13e519524SHoward Hinnant// -*- C++ -*-
23e519524SHoward Hinnant//===-------------------------- algorithm ---------------------------------===//
33e519524SHoward Hinnant//
457b08b09SChandler Carruth// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
557b08b09SChandler Carruth// See https://llvm.org/LICENSE.txt for license information.
657b08b09SChandler Carruth// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
73e519524SHoward Hinnant//
83e519524SHoward Hinnant//===----------------------------------------------------------------------===//
93e519524SHoward Hinnant
103e519524SHoward Hinnant#ifndef _LIBCPP_ALGORITHM
113e519524SHoward Hinnant#define _LIBCPP_ALGORITHM
123e519524SHoward Hinnant
133e519524SHoward Hinnant/*
143e519524SHoward Hinnant    algorithm synopsis
153e519524SHoward Hinnant
163e519524SHoward Hinnant#include <initializer_list>
173e519524SHoward Hinnant
183e519524SHoward Hinnantnamespace std
193e519524SHoward Hinnant{
203e519524SHoward Hinnant
213e519524SHoward Hinnanttemplate <class InputIterator, class Predicate>
22706ffef7SMarshall Clow    constexpr bool     // constexpr in C++20
233e519524SHoward Hinnant    all_of(InputIterator first, InputIterator last, Predicate pred);
243e519524SHoward Hinnant
253e519524SHoward Hinnanttemplate <class InputIterator, class Predicate>
26706ffef7SMarshall Clow    constexpr bool     // constexpr in C++20
273e519524SHoward Hinnant    any_of(InputIterator first, InputIterator last, Predicate pred);
283e519524SHoward Hinnant
293e519524SHoward Hinnanttemplate <class InputIterator, class Predicate>
30706ffef7SMarshall Clow    constexpr bool     // constexpr in C++20
313e519524SHoward Hinnant    none_of(InputIterator first, InputIterator last, Predicate pred);
323e519524SHoward Hinnant
333e519524SHoward Hinnanttemplate <class InputIterator, class Function>
341b9a4ffdSMarshall Clow    constexpr Function          // constexpr in C++20
353e519524SHoward Hinnant    for_each(InputIterator first, InputIterator last, Function f);
363e519524SHoward Hinnant
37d5c65ffaSMarshall Clowtemplate<class InputIterator, class Size, class Function>
381b9a4ffdSMarshall Clow    constexpr InputIterator     // constexpr in C++20
391b9a4ffdSMarshall Clow    for_each_n(InputIterator first, Size n, Function f); // C++17
40d5c65ffaSMarshall Clow
413e519524SHoward Hinnanttemplate <class InputIterator, class T>
4249c7643cSMarshall Clow    constexpr InputIterator     // constexpr in C++20
433e519524SHoward Hinnant    find(InputIterator first, InputIterator last, const T& value);
443e519524SHoward Hinnant
453e519524SHoward Hinnanttemplate <class InputIterator, class Predicate>
4649c7643cSMarshall Clow    constexpr InputIterator     // constexpr in C++20
473e519524SHoward Hinnant    find_if(InputIterator first, InputIterator last, Predicate pred);
483e519524SHoward Hinnant
493e519524SHoward Hinnanttemplate<class InputIterator, class Predicate>
50b8bc4e15SArthur O'Dwyer    constexpr InputIterator     // constexpr in C++20
513e519524SHoward Hinnant    find_if_not(InputIterator first, InputIterator last, Predicate pred);
523e519524SHoward Hinnant
533e519524SHoward Hinnanttemplate <class ForwardIterator1, class ForwardIterator2>
54b8bc4e15SArthur O'Dwyer    constexpr ForwardIterator1  // constexpr in C++20
553e519524SHoward Hinnant    find_end(ForwardIterator1 first1, ForwardIterator1 last1,
563e519524SHoward Hinnant             ForwardIterator2 first2, ForwardIterator2 last2);
573e519524SHoward Hinnant
583e519524SHoward Hinnanttemplate <class ForwardIterator1, class ForwardIterator2, class BinaryPredicate>
59b8bc4e15SArthur O'Dwyer    constexpr ForwardIterator1  // constexpr in C++20
603e519524SHoward Hinnant    find_end(ForwardIterator1 first1, ForwardIterator1 last1,
613e519524SHoward Hinnant             ForwardIterator2 first2, ForwardIterator2 last2, BinaryPredicate pred);
623e519524SHoward Hinnant
633e519524SHoward Hinnanttemplate <class ForwardIterator1, class ForwardIterator2>
648694428eSMarshall Clow    constexpr ForwardIterator1  // constexpr in C++20
653e519524SHoward Hinnant    find_first_of(ForwardIterator1 first1, ForwardIterator1 last1,
663e519524SHoward Hinnant                  ForwardIterator2 first2, ForwardIterator2 last2);
673e519524SHoward Hinnant
683e519524SHoward Hinnanttemplate <class ForwardIterator1, class ForwardIterator2, class BinaryPredicate>
698694428eSMarshall Clow    constexpr ForwardIterator1  // constexpr in C++20
703e519524SHoward Hinnant    find_first_of(ForwardIterator1 first1, ForwardIterator1 last1,
713e519524SHoward Hinnant                  ForwardIterator2 first2, ForwardIterator2 last2, BinaryPredicate pred);
723e519524SHoward Hinnant
733e519524SHoward Hinnanttemplate <class ForwardIterator>
748694428eSMarshall Clow    constexpr ForwardIterator   // constexpr in C++20
753e519524SHoward Hinnant    adjacent_find(ForwardIterator first, ForwardIterator last);
763e519524SHoward Hinnant
773e519524SHoward Hinnanttemplate <class ForwardIterator, class BinaryPredicate>
788694428eSMarshall Clow    constexpr ForwardIterator   // constexpr in C++20
793e519524SHoward Hinnant    adjacent_find(ForwardIterator first, ForwardIterator last, BinaryPredicate pred);
803e519524SHoward Hinnant
813e519524SHoward Hinnanttemplate <class InputIterator, class T>
82056f15e3SMarshall Clow    constexpr typename iterator_traits<InputIterator>::difference_type  // constexpr in C++20
833e519524SHoward Hinnant    count(InputIterator first, InputIterator last, const T& value);
843e519524SHoward Hinnant
853e519524SHoward Hinnanttemplate <class InputIterator, class Predicate>
86056f15e3SMarshall Clow    constexpr typename iterator_traits<InputIterator>::difference_type // constexpr in C++20
873e519524SHoward Hinnant    count_if(InputIterator first, InputIterator last, Predicate pred);
883e519524SHoward Hinnant
893e519524SHoward Hinnanttemplate <class InputIterator1, class InputIterator2>
906538e28dSMarshall Clow    constexpr pair<InputIterator1, InputIterator2>   // constexpr in C++20
913e519524SHoward Hinnant    mismatch(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2);
923e519524SHoward Hinnant
930b0bbd2fSMarshall Clowtemplate <class InputIterator1, class InputIterator2>
946538e28dSMarshall Clow    constexpr pair<InputIterator1, InputIterator2>   // constexpr in C++20
950b0bbd2fSMarshall Clow    mismatch(InputIterator1 first1, InputIterator1 last1,
960b0bbd2fSMarshall Clow             InputIterator2 first2, InputIterator2 last2); // **C++14**
970b0bbd2fSMarshall Clow
983e519524SHoward Hinnanttemplate <class InputIterator1, class InputIterator2, class BinaryPredicate>
996538e28dSMarshall Clow    constexpr pair<InputIterator1, InputIterator2>   // constexpr in C++20
1003e519524SHoward Hinnant    mismatch(InputIterator1 first1, InputIterator1 last1,
1013e519524SHoward Hinnant             InputIterator2 first2, BinaryPredicate pred);
1023e519524SHoward Hinnant
1030b0bbd2fSMarshall Clowtemplate <class InputIterator1, class InputIterator2, class BinaryPredicate>
1046538e28dSMarshall Clow    constexpr pair<InputIterator1, InputIterator2>   // constexpr in C++20
1050b0bbd2fSMarshall Clow    mismatch(InputIterator1 first1, InputIterator1 last1,
1060b0bbd2fSMarshall Clow             InputIterator2 first2, InputIterator2 last2,
1070b0bbd2fSMarshall Clow             BinaryPredicate pred); // **C++14**
1080b0bbd2fSMarshall Clow
1093e519524SHoward Hinnanttemplate <class InputIterator1, class InputIterator2>
1106538e28dSMarshall Clow    constexpr bool      // constexpr in C++20
1113e519524SHoward Hinnant    equal(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2);
1123e519524SHoward Hinnant
1130b0bbd2fSMarshall Clowtemplate <class InputIterator1, class InputIterator2>
1146538e28dSMarshall Clow    constexpr bool      // constexpr in C++20
1150b0bbd2fSMarshall Clow    equal(InputIterator1 first1, InputIterator1 last1,
1160b0bbd2fSMarshall Clow          InputIterator2 first2, InputIterator2 last2); // **C++14**
1170b0bbd2fSMarshall Clow
1183e519524SHoward Hinnanttemplate <class InputIterator1, class InputIterator2, class BinaryPredicate>
1196538e28dSMarshall Clow    constexpr bool      // constexpr in C++20
1203e519524SHoward Hinnant    equal(InputIterator1 first1, InputIterator1 last1,
1213e519524SHoward Hinnant          InputIterator2 first2, BinaryPredicate pred);
1223e519524SHoward Hinnant
1230b0bbd2fSMarshall Clowtemplate <class InputIterator1, class InputIterator2, class BinaryPredicate>
1246538e28dSMarshall Clow    constexpr bool      // constexpr in C++20
1250b0bbd2fSMarshall Clow    equal(InputIterator1 first1, InputIterator1 last1,
1260b0bbd2fSMarshall Clow          InputIterator2 first2, InputIterator2 last2,
1270b0bbd2fSMarshall Clow          BinaryPredicate pred); // **C++14**
1280b0bbd2fSMarshall Clow
1293e519524SHoward Hinnanttemplate<class ForwardIterator1, class ForwardIterator2>
13049c7643cSMarshall Clow    constexpr bool      // constexpr in C++20
1313e519524SHoward Hinnant    is_permutation(ForwardIterator1 first1, ForwardIterator1 last1,
1323e519524SHoward Hinnant                   ForwardIterator2 first2);
1333e519524SHoward Hinnant
1340b0bbd2fSMarshall Clowtemplate<class ForwardIterator1, class ForwardIterator2>
13549c7643cSMarshall Clow    constexpr bool      // constexpr in C++20
1360b0bbd2fSMarshall Clow    is_permutation(ForwardIterator1 first1, ForwardIterator1 last1,
1370b0bbd2fSMarshall Clow                   ForwardIterator2 first2, ForwardIterator2 last2); // **C++14**
1380b0bbd2fSMarshall Clow
1393e519524SHoward Hinnanttemplate<class ForwardIterator1, class ForwardIterator2, class BinaryPredicate>
14049c7643cSMarshall Clow    constexpr bool      // constexpr in C++20
1413e519524SHoward Hinnant    is_permutation(ForwardIterator1 first1, ForwardIterator1 last1,
1423e519524SHoward Hinnant                   ForwardIterator2 first2, BinaryPredicate pred);
1433e519524SHoward Hinnant
1440b0bbd2fSMarshall Clowtemplate<class ForwardIterator1, class ForwardIterator2, class BinaryPredicate>
14549c7643cSMarshall Clow    constexpr bool      // constexpr in C++20
1460b0bbd2fSMarshall Clow    is_permutation(ForwardIterator1 first1, ForwardIterator1 last1,
1470b0bbd2fSMarshall Clow                   ForwardIterator2 first2, ForwardIterator2 last2,
1480b0bbd2fSMarshall Clow                   BinaryPredicate pred);  // **C++14**
1490b0bbd2fSMarshall Clow
1503e519524SHoward Hinnanttemplate <class ForwardIterator1, class ForwardIterator2>
15112f0a779SMarshall Clow    constexpr ForwardIterator1      // constexpr in C++20
1523e519524SHoward Hinnant    search(ForwardIterator1 first1, ForwardIterator1 last1,
1533e519524SHoward Hinnant           ForwardIterator2 first2, ForwardIterator2 last2);
1543e519524SHoward Hinnant
1553e519524SHoward Hinnanttemplate <class ForwardIterator1, class ForwardIterator2, class BinaryPredicate>
15612f0a779SMarshall Clow    constexpr ForwardIterator1      // constexpr in C++20
1573e519524SHoward Hinnant    search(ForwardIterator1 first1, ForwardIterator1 last1,
1583e519524SHoward Hinnant           ForwardIterator2 first2, ForwardIterator2 last2, BinaryPredicate pred);
1593e519524SHoward Hinnant
1603e519524SHoward Hinnanttemplate <class ForwardIterator, class Size, class T>
16112f0a779SMarshall Clow    constexpr ForwardIterator       // constexpr in C++20
1623e519524SHoward Hinnant    search_n(ForwardIterator first, ForwardIterator last, Size count, const T& value);
1633e519524SHoward Hinnant
1643e519524SHoward Hinnanttemplate <class ForwardIterator, class Size, class T, class BinaryPredicate>
16512f0a779SMarshall Clow    constexpr ForwardIterator       // constexpr in C++20
1663e519524SHoward Hinnant    search_n(ForwardIterator first, ForwardIterator last,
1673e519524SHoward Hinnant             Size count, const T& value, BinaryPredicate pred);
1683e519524SHoward Hinnant
1693e519524SHoward Hinnanttemplate <class InputIterator, class OutputIterator>
17013c90a57SLouis Dionne    constexpr OutputIterator      // constexpr in C++20
1713e519524SHoward Hinnant    copy(InputIterator first, InputIterator last, OutputIterator result);
1723e519524SHoward Hinnant
1733e519524SHoward Hinnanttemplate<class InputIterator, class OutputIterator, class Predicate>
17413c90a57SLouis Dionne    constexpr OutputIterator      // constexpr in C++20
1753e519524SHoward Hinnant    copy_if(InputIterator first, InputIterator last,
1763e519524SHoward Hinnant            OutputIterator result, Predicate pred);
1773e519524SHoward Hinnant
1783e519524SHoward Hinnanttemplate<class InputIterator, class Size, class OutputIterator>
17913c90a57SLouis Dionne    constexpr OutputIterator      // constexpr in C++20
1803e519524SHoward Hinnant    copy_n(InputIterator first, Size n, OutputIterator result);
1813e519524SHoward Hinnant
1823e519524SHoward Hinnanttemplate <class BidirectionalIterator1, class BidirectionalIterator2>
18313c90a57SLouis Dionne    constexpr BidirectionalIterator2      // constexpr in C++20
1843e519524SHoward Hinnant    copy_backward(BidirectionalIterator1 first, BidirectionalIterator1 last,
1853e519524SHoward Hinnant                  BidirectionalIterator2 result);
1863e519524SHoward Hinnant
1873e519524SHoward Hinnanttemplate <class ForwardIterator1, class ForwardIterator2>
188b8bc4e15SArthur O'Dwyer    constexpr ForwardIterator2    // constexpr in C++20
1893e519524SHoward Hinnant    swap_ranges(ForwardIterator1 first1, ForwardIterator1 last1, ForwardIterator2 first2);
1903e519524SHoward Hinnant
1913e519524SHoward Hinnanttemplate <class ForwardIterator1, class ForwardIterator2>
192b8bc4e15SArthur O'Dwyer    constexpr void                // constexpr in C++20
1933e519524SHoward Hinnant    iter_swap(ForwardIterator1 a, ForwardIterator2 b);
1943e519524SHoward Hinnant
1953e519524SHoward Hinnanttemplate <class InputIterator, class OutputIterator, class UnaryOperation>
19699894b61SMarshall Clow    constexpr OutputIterator      // constexpr in C++20
1973e519524SHoward Hinnant    transform(InputIterator first, InputIterator last, OutputIterator result, UnaryOperation op);
1983e519524SHoward Hinnant
1993e519524SHoward Hinnanttemplate <class InputIterator1, class InputIterator2, class OutputIterator, class BinaryOperation>
20099894b61SMarshall Clow    constexpr OutputIterator      // constexpr in C++20
2013e519524SHoward Hinnant    transform(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2,
2023e519524SHoward Hinnant              OutputIterator result, BinaryOperation binary_op);
2033e519524SHoward Hinnant
2043e519524SHoward Hinnanttemplate <class ForwardIterator, class T>
20512c7423fSMarshall Clow    constexpr void      // constexpr in C++20
2063e519524SHoward Hinnant    replace(ForwardIterator first, ForwardIterator last, const T& old_value, const T& new_value);
2073e519524SHoward Hinnant
2083e519524SHoward Hinnanttemplate <class ForwardIterator, class Predicate, class T>
20912c7423fSMarshall Clow    constexpr void      // constexpr in C++20
2103e519524SHoward Hinnant    replace_if(ForwardIterator first, ForwardIterator last, Predicate pred, const T& new_value);
2113e519524SHoward Hinnant
2123e519524SHoward Hinnanttemplate <class InputIterator, class OutputIterator, class T>
21312c7423fSMarshall Clow    constexpr OutputIterator      // constexpr in C++20
2143e519524SHoward Hinnant    replace_copy(InputIterator first, InputIterator last, OutputIterator result,
2153e519524SHoward Hinnant                 const T& old_value, const T& new_value);
2163e519524SHoward Hinnant
2173e519524SHoward Hinnanttemplate <class InputIterator, class OutputIterator, class Predicate, class T>
21812c7423fSMarshall Clow    constexpr OutputIterator      // constexpr in C++20
2193e519524SHoward Hinnant    replace_copy_if(InputIterator first, InputIterator last, OutputIterator result, Predicate pred, const T& new_value);
2203e519524SHoward Hinnant
2213e519524SHoward Hinnanttemplate <class ForwardIterator, class T>
2224bfb9313SMarshall Clow    constexpr void      // constexpr in C++20
2233e519524SHoward Hinnant    fill(ForwardIterator first, ForwardIterator last, const T& value);
2243e519524SHoward Hinnant
2253e519524SHoward Hinnanttemplate <class OutputIterator, class Size, class T>
2264bfb9313SMarshall Clow    constexpr OutputIterator      // constexpr in C++20
2273e519524SHoward Hinnant    fill_n(OutputIterator first, Size n, const T& value);
2283e519524SHoward Hinnant
2293e519524SHoward Hinnanttemplate <class ForwardIterator, class Generator>
2304bfb9313SMarshall Clow    constexpr void      // constexpr in C++20
2313e519524SHoward Hinnant    generate(ForwardIterator first, ForwardIterator last, Generator gen);
2323e519524SHoward Hinnant
2333e519524SHoward Hinnanttemplate <class OutputIterator, class Size, class Generator>
2344bfb9313SMarshall Clow    constexpr OutputIterator      // constexpr in C++20
2353e519524SHoward Hinnant    generate_n(OutputIterator first, Size n, Generator gen);
2363e519524SHoward Hinnant
2373e519524SHoward Hinnanttemplate <class ForwardIterator, class T>
238e8ea8296SMarshall Clow    constexpr ForwardIterator     // constexpr in C++20
2393e519524SHoward Hinnant    remove(ForwardIterator first, ForwardIterator last, const T& value);
2403e519524SHoward Hinnant
2413e519524SHoward Hinnanttemplate <class ForwardIterator, class Predicate>
242e8ea8296SMarshall Clow    constexpr ForwardIterator     // constexpr in C++20
2433e519524SHoward Hinnant    remove_if(ForwardIterator first, ForwardIterator last, Predicate pred);
2443e519524SHoward Hinnant
2453e519524SHoward Hinnanttemplate <class InputIterator, class OutputIterator, class T>
246e8ea8296SMarshall Clow    constexpr OutputIterator     // constexpr in C++20
2473e519524SHoward Hinnant    remove_copy(InputIterator first, InputIterator last, OutputIterator result, const T& value);
2483e519524SHoward Hinnant
2493e519524SHoward Hinnanttemplate <class InputIterator, class OutputIterator, class Predicate>
250e8ea8296SMarshall Clow    constexpr OutputIterator     // constexpr in C++20
2513e519524SHoward Hinnant    remove_copy_if(InputIterator first, InputIterator last, OutputIterator result, Predicate pred);
2523e519524SHoward Hinnant
2533e519524SHoward Hinnanttemplate <class ForwardIterator>
254b8bc4e15SArthur O'Dwyer    constexpr ForwardIterator    // constexpr in C++20
2553e519524SHoward Hinnant    unique(ForwardIterator first, ForwardIterator last);
2563e519524SHoward Hinnant
2573e519524SHoward Hinnanttemplate <class ForwardIterator, class BinaryPredicate>
258b8bc4e15SArthur O'Dwyer    constexpr ForwardIterator    // constexpr in C++20
2593e519524SHoward Hinnant    unique(ForwardIterator first, ForwardIterator last, BinaryPredicate pred);
2603e519524SHoward Hinnant
2613e519524SHoward Hinnanttemplate <class InputIterator, class OutputIterator>
262b8bc4e15SArthur O'Dwyer    constexpr OutputIterator     // constexpr in C++20
2633e519524SHoward Hinnant    unique_copy(InputIterator first, InputIterator last, OutputIterator result);
2643e519524SHoward Hinnant
2653e519524SHoward Hinnanttemplate <class InputIterator, class OutputIterator, class BinaryPredicate>
266b8bc4e15SArthur O'Dwyer    constexpr OutputIterator     // constexpr in C++20
2673e519524SHoward Hinnant    unique_copy(InputIterator first, InputIterator last, OutputIterator result, BinaryPredicate pred);
2683e519524SHoward Hinnant
2693e519524SHoward Hinnanttemplate <class BidirectionalIterator>
270f851db3dSArthur O'Dwyer    constexpr void               // constexpr in C++20
2713e519524SHoward Hinnant    reverse(BidirectionalIterator first, BidirectionalIterator last);
2723e519524SHoward Hinnant
2733e519524SHoward Hinnanttemplate <class BidirectionalIterator, class OutputIterator>
274e8ea8296SMarshall Clow    constexpr OutputIterator       // constexpr in C++20
2753e519524SHoward Hinnant    reverse_copy(BidirectionalIterator first, BidirectionalIterator last, OutputIterator result);
2763e519524SHoward Hinnant
2773e519524SHoward Hinnanttemplate <class ForwardIterator>
278b8bc4e15SArthur O'Dwyer    constexpr ForwardIterator      // constexpr in C++20
2793e519524SHoward Hinnant    rotate(ForwardIterator first, ForwardIterator middle, ForwardIterator last);
2803e519524SHoward Hinnant
2813e519524SHoward Hinnanttemplate <class ForwardIterator, class OutputIterator>
282b8bc4e15SArthur O'Dwyer    constexpr OutputIterator       // constexpr in C++20
2833e519524SHoward Hinnant    rotate_copy(ForwardIterator first, ForwardIterator middle, ForwardIterator last, OutputIterator result);
2843e519524SHoward Hinnant
2853e519524SHoward Hinnanttemplate <class RandomAccessIterator>
2863e519524SHoward Hinnant    void
2870f37a410SMarshall Clow    random_shuffle(RandomAccessIterator first, RandomAccessIterator last); // deprecated in C++14, removed in C++17
2883e519524SHoward Hinnant
2893e519524SHoward Hinnanttemplate <class RandomAccessIterator, class RandomNumberGenerator>
2903e519524SHoward Hinnant    void
29106965c1fSMarshall Clow    random_shuffle(RandomAccessIterator first, RandomAccessIterator last,
2920f37a410SMarshall Clow                   RandomNumberGenerator& rand);  // deprecated in C++14, removed in C++17
2933e519524SHoward Hinnant
294e7154709SEric Fiseliertemplate<class PopulationIterator, class SampleIterator,
295e7154709SEric Fiselier         class Distance, class UniformRandomBitGenerator>
296e7154709SEric Fiselier    SampleIterator sample(PopulationIterator first, PopulationIterator last,
297e7154709SEric Fiselier                          SampleIterator out, Distance n,
298e7154709SEric Fiselier                          UniformRandomBitGenerator&& g); // C++17
299e7154709SEric Fiselier
300f9d540b0SHoward Hinnanttemplate<class RandomAccessIterator, class UniformRandomNumberGenerator>
301f9d540b0SHoward Hinnant    void shuffle(RandomAccessIterator first, RandomAccessIterator last,
302fb340102SHoward Hinnant                 UniformRandomNumberGenerator&& g);
303f9d540b0SHoward Hinnant
3043fbd3eafSArthur O'Dwyertemplate<class ForwardIterator>
3053fbd3eafSArthur O'Dwyer  constexpr ForwardIterator
3063fbd3eafSArthur O'Dwyer    shift_left(ForwardIterator first, ForwardIterator last,
3073fbd3eafSArthur O'Dwyer               typename iterator_traits<ForwardIterator>::difference_type n); // C++20
3083fbd3eafSArthur O'Dwyer
3093fbd3eafSArthur O'Dwyertemplate<class ForwardIterator>
3103fbd3eafSArthur O'Dwyer  constexpr ForwardIterator
3113fbd3eafSArthur O'Dwyer    shift_right(ForwardIterator first, ForwardIterator last,
3123fbd3eafSArthur O'Dwyer                typename iterator_traits<ForwardIterator>::difference_type n); // C++20
3133fbd3eafSArthur O'Dwyer
3143e519524SHoward Hinnanttemplate <class InputIterator, class Predicate>
31549c7643cSMarshall Clow    constexpr bool  // constexpr in C++20
3163e519524SHoward Hinnant    is_partitioned(InputIterator first, InputIterator last, Predicate pred);
3173e519524SHoward Hinnant
3183e519524SHoward Hinnanttemplate <class ForwardIterator, class Predicate>
319f851db3dSArthur O'Dwyer    constexpr ForwardIterator  // constexpr in C++20
3203e519524SHoward Hinnant    partition(ForwardIterator first, ForwardIterator last, Predicate pred);
3213e519524SHoward Hinnant
3223e519524SHoward Hinnanttemplate <class InputIterator, class OutputIterator1,
3233e519524SHoward Hinnant          class OutputIterator2, class Predicate>
3241b9a4ffdSMarshall Clow    constexpr pair<OutputIterator1, OutputIterator2>   // constexpr in C++20
3253e519524SHoward Hinnant    partition_copy(InputIterator first, InputIterator last,
3263e519524SHoward Hinnant                   OutputIterator1 out_true, OutputIterator2 out_false,
3273e519524SHoward Hinnant                   Predicate pred);
3283e519524SHoward Hinnant
3293e519524SHoward Hinnanttemplate <class ForwardIterator, class Predicate>
3303e519524SHoward Hinnant    ForwardIterator
3313e519524SHoward Hinnant    stable_partition(ForwardIterator first, ForwardIterator last, Predicate pred);
3323e519524SHoward Hinnant
3333e519524SHoward Hinnanttemplate<class ForwardIterator, class Predicate>
334d57c03ddSMarshall Clow    constexpr ForwardIterator  // constexpr in C++20
3353e519524SHoward Hinnant    partition_point(ForwardIterator first, ForwardIterator last, Predicate pred);
3363e519524SHoward Hinnant
3373e519524SHoward Hinnanttemplate <class ForwardIterator>
33849c7643cSMarshall Clow    constexpr bool  // constexpr in C++20
3393e519524SHoward Hinnant    is_sorted(ForwardIterator first, ForwardIterator last);
3403e519524SHoward Hinnant
3413e519524SHoward Hinnanttemplate <class ForwardIterator, class Compare>
342b8bc4e15SArthur O'Dwyer    constexpr bool  // constexpr in C++20
3433e519524SHoward Hinnant    is_sorted(ForwardIterator first, ForwardIterator last, Compare comp);
3443e519524SHoward Hinnant
3453e519524SHoward Hinnanttemplate<class ForwardIterator>
346056f15e3SMarshall Clow    constexpr ForwardIterator    // constexpr in C++20
3473e519524SHoward Hinnant    is_sorted_until(ForwardIterator first, ForwardIterator last);
3483e519524SHoward Hinnant
3493e519524SHoward Hinnanttemplate <class ForwardIterator, class Compare>
350056f15e3SMarshall Clow    constexpr ForwardIterator    // constexpr in C++20
3513e519524SHoward Hinnant    is_sorted_until(ForwardIterator first, ForwardIterator last, Compare comp);
3523e519524SHoward Hinnant
3533e519524SHoward Hinnanttemplate <class RandomAccessIterator>
354493f1407SArthur O'Dwyer    constexpr void               // constexpr in C++20
3553e519524SHoward Hinnant    sort(RandomAccessIterator first, RandomAccessIterator last);
3563e519524SHoward Hinnant
3573e519524SHoward Hinnanttemplate <class RandomAccessIterator, class Compare>
358493f1407SArthur O'Dwyer    constexpr void               // constexpr in C++20
3593e519524SHoward Hinnant    sort(RandomAccessIterator first, RandomAccessIterator last, Compare comp);
3603e519524SHoward Hinnant
3613e519524SHoward Hinnanttemplate <class RandomAccessIterator>
3623e519524SHoward Hinnant    void
3633e519524SHoward Hinnant    stable_sort(RandomAccessIterator first, RandomAccessIterator last);
3643e519524SHoward Hinnant
3653e519524SHoward Hinnanttemplate <class RandomAccessIterator, class Compare>
3663e519524SHoward Hinnant    void
3673e519524SHoward Hinnant    stable_sort(RandomAccessIterator first, RandomAccessIterator last, Compare comp);
3683e519524SHoward Hinnant
3693e519524SHoward Hinnanttemplate <class RandomAccessIterator>
3705386aa26SArthur O'Dwyer    constexpr void                    // constexpr in C++20
3713e519524SHoward Hinnant    partial_sort(RandomAccessIterator first, RandomAccessIterator middle, RandomAccessIterator last);
3723e519524SHoward Hinnant
3733e519524SHoward Hinnanttemplate <class RandomAccessIterator, class Compare>
3745386aa26SArthur O'Dwyer    constexpr void                    // constexpr in C++20
3753e519524SHoward Hinnant    partial_sort(RandomAccessIterator first, RandomAccessIterator middle, RandomAccessIterator last, Compare comp);
3763e519524SHoward Hinnant
3773e519524SHoward Hinnanttemplate <class InputIterator, class RandomAccessIterator>
3785386aa26SArthur O'Dwyer    constexpr RandomAccessIterator    // constexpr in C++20
3793e519524SHoward Hinnant    partial_sort_copy(InputIterator first, InputIterator last,
3803e519524SHoward Hinnant                      RandomAccessIterator result_first, RandomAccessIterator result_last);
3813e519524SHoward Hinnant
3823e519524SHoward Hinnanttemplate <class InputIterator, class RandomAccessIterator, class Compare>
3835386aa26SArthur O'Dwyer    constexpr RandomAccessIterator    // constexpr in C++20
3843e519524SHoward Hinnant    partial_sort_copy(InputIterator first, InputIterator last,
3853e519524SHoward Hinnant                      RandomAccessIterator result_first, RandomAccessIterator result_last, Compare comp);
3863e519524SHoward Hinnant
3873e519524SHoward Hinnanttemplate <class RandomAccessIterator>
388*b6ffece3SJordan Rupprecht    void
3893e519524SHoward Hinnant    nth_element(RandomAccessIterator first, RandomAccessIterator nth, RandomAccessIterator last);
3903e519524SHoward Hinnant
3913e519524SHoward Hinnanttemplate <class RandomAccessIterator, class Compare>
392*b6ffece3SJordan Rupprecht    void
3933e519524SHoward Hinnant    nth_element(RandomAccessIterator first, RandomAccessIterator nth, RandomAccessIterator last, Compare comp);
3943e519524SHoward Hinnant
3953e519524SHoward Hinnanttemplate <class ForwardIterator, class T>
396d57c03ddSMarshall Clow    constexpr ForwardIterator                         // constexpr in C++20
3973e519524SHoward Hinnant    lower_bound(ForwardIterator first, ForwardIterator last, const T& value);
3983e519524SHoward Hinnant
3993e519524SHoward Hinnanttemplate <class ForwardIterator, class T, class Compare>
400d57c03ddSMarshall Clow    constexpr ForwardIterator                         // constexpr in C++20
4013e519524SHoward Hinnant    lower_bound(ForwardIterator first, ForwardIterator last, const T& value, Compare comp);
4023e519524SHoward Hinnant
4033e519524SHoward Hinnanttemplate <class ForwardIterator, class T>
404d57c03ddSMarshall Clow    constexpr ForwardIterator                         // constexpr in C++20
4053e519524SHoward Hinnant    upper_bound(ForwardIterator first, ForwardIterator last, const T& value);
4063e519524SHoward Hinnant
4073e519524SHoward Hinnanttemplate <class ForwardIterator, class T, class Compare>
408d57c03ddSMarshall Clow    constexpr ForwardIterator                         // constexpr in C++20
4093e519524SHoward Hinnant    upper_bound(ForwardIterator first, ForwardIterator last, const T& value, Compare comp);
4103e519524SHoward Hinnant
4113e519524SHoward Hinnanttemplate <class ForwardIterator, class T>
412d57c03ddSMarshall Clow    constexpr pair<ForwardIterator, ForwardIterator>  // constexpr in C++20
4133e519524SHoward Hinnant    equal_range(ForwardIterator first, ForwardIterator last, const T& value);
4143e519524SHoward Hinnant
4153e519524SHoward Hinnanttemplate <class ForwardIterator, class T, class Compare>
416d57c03ddSMarshall Clow    constexpr pair<ForwardIterator, ForwardIterator>  // constexpr in C++20
4173e519524SHoward Hinnant    equal_range(ForwardIterator first, ForwardIterator last, const T& value, Compare comp);
4183e519524SHoward Hinnant
4193e519524SHoward Hinnanttemplate <class ForwardIterator, class T>
420d57c03ddSMarshall Clow    constexpr bool                                    // constexpr in C++20
4213e519524SHoward Hinnant    binary_search(ForwardIterator first, ForwardIterator last, const T& value);
4223e519524SHoward Hinnant
4233e519524SHoward Hinnanttemplate <class ForwardIterator, class T, class Compare>
4248da1a487SMarshall Clow    constexpr bool                                    // constexpr in C++20
4253e519524SHoward Hinnant    binary_search(ForwardIterator first, ForwardIterator last, const T& value, Compare comp);
4263e519524SHoward Hinnant
4273e519524SHoward Hinnanttemplate <class InputIterator1, class InputIterator2, class OutputIterator>
42814098cf6SArthur O'Dwyer    constexpr OutputIterator                          // constexpr in C++20
4293e519524SHoward Hinnant    merge(InputIterator1 first1, InputIterator1 last1,
4303e519524SHoward Hinnant          InputIterator2 first2, InputIterator2 last2, OutputIterator result);
4313e519524SHoward Hinnant
4323e519524SHoward Hinnanttemplate <class InputIterator1, class InputIterator2, class OutputIterator, class Compare>
43314098cf6SArthur O'Dwyer    constexpr OutputIterator                          // constexpr in C++20
4343e519524SHoward Hinnant    merge(InputIterator1 first1, InputIterator1 last1,
4353e519524SHoward Hinnant          InputIterator2 first2, InputIterator2 last2, OutputIterator result, Compare comp);
4363e519524SHoward Hinnant
4373e519524SHoward Hinnanttemplate <class BidirectionalIterator>
4383e519524SHoward Hinnant    void
4393e519524SHoward Hinnant    inplace_merge(BidirectionalIterator first, BidirectionalIterator middle, BidirectionalIterator last);
4403e519524SHoward Hinnant
4413e519524SHoward Hinnanttemplate <class BidirectionalIterator, class Compare>
4423e519524SHoward Hinnant    void
4433e519524SHoward Hinnant    inplace_merge(BidirectionalIterator first, BidirectionalIterator middle, BidirectionalIterator last, Compare comp);
4443e519524SHoward Hinnant
4453e519524SHoward Hinnanttemplate <class InputIterator1, class InputIterator2>
4468da1a487SMarshall Clow    constexpr bool                                    // constexpr in C++20
4473e519524SHoward Hinnant    includes(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, InputIterator2 last2);
4483e519524SHoward Hinnant
4493e519524SHoward Hinnanttemplate <class InputIterator1, class InputIterator2, class Compare>
4508da1a487SMarshall Clow    constexpr bool                                    // constexpr in C++20
4513e519524SHoward Hinnant    includes(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, InputIterator2 last2, Compare comp);
4523e519524SHoward Hinnant
4533e519524SHoward Hinnanttemplate <class InputIterator1, class InputIterator2, class OutputIterator>
45414098cf6SArthur O'Dwyer    constexpr OutputIterator                          // constexpr in C++20
4553e519524SHoward Hinnant    set_union(InputIterator1 first1, InputIterator1 last1,
4563e519524SHoward Hinnant              InputIterator2 first2, InputIterator2 last2, OutputIterator result);
4573e519524SHoward Hinnant
4583e519524SHoward Hinnanttemplate <class InputIterator1, class InputIterator2, class OutputIterator, class Compare>
45914098cf6SArthur O'Dwyer    constexpr OutputIterator                          // constexpr in C++20
4603e519524SHoward Hinnant    set_union(InputIterator1 first1, InputIterator1 last1,
4613e519524SHoward Hinnant              InputIterator2 first2, InputIterator2 last2, OutputIterator result, Compare comp);
4623e519524SHoward Hinnant
4633e519524SHoward Hinnanttemplate <class InputIterator1, class InputIterator2, class OutputIterator>
4648da1a487SMarshall Clow    constexpr OutputIterator                         // constexpr in C++20
4653e519524SHoward Hinnant    set_intersection(InputIterator1 first1, InputIterator1 last1,
4663e519524SHoward Hinnant                     InputIterator2 first2, InputIterator2 last2, OutputIterator result);
4673e519524SHoward Hinnant
4683e519524SHoward Hinnanttemplate <class InputIterator1, class InputIterator2, class OutputIterator, class Compare>
4698da1a487SMarshall Clow    constexpr OutputIterator                         // constexpr in C++20
4703e519524SHoward Hinnant    set_intersection(InputIterator1 first1, InputIterator1 last1,
4713e519524SHoward Hinnant                     InputIterator2 first2, InputIterator2 last2, OutputIterator result, Compare comp);
4723e519524SHoward Hinnant
4733e519524SHoward Hinnanttemplate <class InputIterator1, class InputIterator2, class OutputIterator>
47414098cf6SArthur O'Dwyer    constexpr OutputIterator                         // constexpr in C++20
4753e519524SHoward Hinnant    set_difference(InputIterator1 first1, InputIterator1 last1,
4763e519524SHoward Hinnant                   InputIterator2 first2, InputIterator2 last2, OutputIterator result);
4773e519524SHoward Hinnant
4783e519524SHoward Hinnanttemplate <class InputIterator1, class InputIterator2, class OutputIterator, class Compare>
47914098cf6SArthur O'Dwyer    constexpr OutputIterator                         // constexpr in C++20
4803e519524SHoward Hinnant    set_difference(InputIterator1 first1, InputIterator1 last1,
4813e519524SHoward Hinnant                   InputIterator2 first2, InputIterator2 last2, OutputIterator result, Compare comp);
4823e519524SHoward Hinnant
4833e519524SHoward Hinnanttemplate <class InputIterator1, class InputIterator2, class OutputIterator>
48414098cf6SArthur O'Dwyer    constexpr OutputIterator                         // constexpr in C++20
4853e519524SHoward Hinnant    set_symmetric_difference(InputIterator1 first1, InputIterator1 last1,
4863e519524SHoward Hinnant                             InputIterator2 first2, InputIterator2 last2, OutputIterator result);
4873e519524SHoward Hinnant
4883e519524SHoward Hinnanttemplate <class InputIterator1, class InputIterator2, class OutputIterator, class Compare>
48914098cf6SArthur O'Dwyer    constexpr OutputIterator                         // constexpr in C++20
4903e519524SHoward Hinnant    set_symmetric_difference(InputIterator1 first1, InputIterator1 last1,
4913e519524SHoward Hinnant                             InputIterator2 first2, InputIterator2 last2, OutputIterator result, Compare comp);
4923e519524SHoward Hinnant
4933e519524SHoward Hinnanttemplate <class RandomAccessIterator>
4945386aa26SArthur O'Dwyer    constexpr void                                   // constexpr in C++20
4953e519524SHoward Hinnant    push_heap(RandomAccessIterator first, RandomAccessIterator last);
4963e519524SHoward Hinnant
4973e519524SHoward Hinnanttemplate <class RandomAccessIterator, class Compare>
4985386aa26SArthur O'Dwyer    constexpr void                                   // constexpr in C++20
4993e519524SHoward Hinnant    push_heap(RandomAccessIterator first, RandomAccessIterator last, Compare comp);
5003e519524SHoward Hinnant
5013e519524SHoward Hinnanttemplate <class RandomAccessIterator>
5025386aa26SArthur O'Dwyer    constexpr void                                   // constexpr in C++20
5033e519524SHoward Hinnant    pop_heap(RandomAccessIterator first, RandomAccessIterator last);
5043e519524SHoward Hinnant
5053e519524SHoward Hinnanttemplate <class RandomAccessIterator, class Compare>
5065386aa26SArthur O'Dwyer    constexpr void                                   // constexpr in C++20
5073e519524SHoward Hinnant    pop_heap(RandomAccessIterator first, RandomAccessIterator last, Compare comp);
5083e519524SHoward Hinnant
5093e519524SHoward Hinnanttemplate <class RandomAccessIterator>
5105386aa26SArthur O'Dwyer    constexpr void                                   // constexpr in C++20
5113e519524SHoward Hinnant    make_heap(RandomAccessIterator first, RandomAccessIterator last);
5123e519524SHoward Hinnant
5133e519524SHoward Hinnanttemplate <class RandomAccessIterator, class Compare>
5145386aa26SArthur O'Dwyer    constexpr void                                   // constexpr in C++20
5153e519524SHoward Hinnant    make_heap(RandomAccessIterator first, RandomAccessIterator last, Compare comp);
5163e519524SHoward Hinnant
5173e519524SHoward Hinnanttemplate <class RandomAccessIterator>
5185386aa26SArthur O'Dwyer    constexpr void                                   // constexpr in C++20
5193e519524SHoward Hinnant    sort_heap(RandomAccessIterator first, RandomAccessIterator last);
5203e519524SHoward Hinnant
5213e519524SHoward Hinnanttemplate <class RandomAccessIterator, class Compare>
5225386aa26SArthur O'Dwyer    constexpr void                                   // constexpr in C++20
5233e519524SHoward Hinnant    sort_heap(RandomAccessIterator first, RandomAccessIterator last, Compare comp);
5243e519524SHoward Hinnant
5253e519524SHoward Hinnanttemplate <class RandomAccessIterator>
52649c7643cSMarshall Clow    constexpr bool   // constexpr in C++20
5273e519524SHoward Hinnant    is_heap(RandomAccessIterator first, RandomAccessiterator last);
5283e519524SHoward Hinnant
5293e519524SHoward Hinnanttemplate <class RandomAccessIterator, class Compare>
53049c7643cSMarshall Clow    constexpr bool   // constexpr in C++20
5313e519524SHoward Hinnant    is_heap(RandomAccessIterator first, RandomAccessiterator last, Compare comp);
5323e519524SHoward Hinnant
5333e519524SHoward Hinnanttemplate <class RandomAccessIterator>
53449c7643cSMarshall Clow    constexpr RandomAccessIterator   // constexpr in C++20
5353e519524SHoward Hinnant    is_heap_until(RandomAccessIterator first, RandomAccessiterator last);
5363e519524SHoward Hinnant
5373e519524SHoward Hinnanttemplate <class RandomAccessIterator, class Compare>
53849c7643cSMarshall Clow    constexpr RandomAccessIterator   // constexpr in C++20
5393e519524SHoward Hinnant    is_heap_until(RandomAccessIterator first, RandomAccessiterator last, Compare comp);
5403e519524SHoward Hinnant
5414eb27b79SHoward Hinnanttemplate <class ForwardIterator>
542b8bc4e15SArthur O'Dwyer    constexpr ForwardIterator        // constexpr in C++14
543b8bc4e15SArthur O'Dwyer    min_element(ForwardIterator first, ForwardIterator last);
5444eb27b79SHoward Hinnant
5454eb27b79SHoward Hinnanttemplate <class ForwardIterator, class Compare>
546b8bc4e15SArthur O'Dwyer    constexpr ForwardIterator        // constexpr in C++14
547b8bc4e15SArthur O'Dwyer    min_element(ForwardIterator first, ForwardIterator last, Compare comp);
5484eb27b79SHoward Hinnant
5493e519524SHoward Hinnanttemplate <class T>
550b8bc4e15SArthur O'Dwyer    constexpr const T&               // constexpr in C++14
551b8bc4e15SArthur O'Dwyer    min(const T& a, const T& b);
5523e519524SHoward Hinnant
5533e519524SHoward Hinnanttemplate <class T, class Compare>
554b8bc4e15SArthur O'Dwyer    constexpr const T&               // constexpr in C++14
555b8bc4e15SArthur O'Dwyer    min(const T& a, const T& b, Compare comp);
5563e519524SHoward Hinnant
5573e519524SHoward Hinnanttemplate<class T>
558b8bc4e15SArthur O'Dwyer    constexpr T                      // constexpr in C++14
559b8bc4e15SArthur O'Dwyer    min(initializer_list<T> t);
5603e519524SHoward Hinnant
5613e519524SHoward Hinnanttemplate<class T, class Compare>
562b8bc4e15SArthur O'Dwyer    constexpr T                      // constexpr in C++14
563b8bc4e15SArthur O'Dwyer    min(initializer_list<T> t, Compare comp);
5643e519524SHoward Hinnant
565146c14acSMarshall Clowtemplate<class T>
566146c14acSMarshall Clow    constexpr const T& clamp(const T& v, const T& lo, const T& hi);               // C++17
567146c14acSMarshall Clow
568146c14acSMarshall Clowtemplate<class T, class Compare>
569146c14acSMarshall Clow    constexpr const T& clamp(const T& v, const T& lo, const T& hi, Compare comp); // C++17
570146c14acSMarshall Clow
5713e519524SHoward Hinnanttemplate <class ForwardIterator>
572b8bc4e15SArthur O'Dwyer    constexpr ForwardIterator        // constexpr in C++14
573b8bc4e15SArthur O'Dwyer    max_element(ForwardIterator first, ForwardIterator last);
5743e519524SHoward Hinnant
5753e519524SHoward Hinnanttemplate <class ForwardIterator, class Compare>
576b8bc4e15SArthur O'Dwyer    constexpr ForwardIterator        // constexpr in C++14
577b8bc4e15SArthur O'Dwyer    max_element(ForwardIterator first, ForwardIterator last, Compare comp);
5783e519524SHoward Hinnant
5794eb27b79SHoward Hinnanttemplate <class T>
580b8bc4e15SArthur O'Dwyer    constexpr const T&               // constexpr in C++14
581b8bc4e15SArthur O'Dwyer    max(const T& a, const T& b);
5824eb27b79SHoward Hinnant
5834eb27b79SHoward Hinnanttemplate <class T, class Compare>
584b8bc4e15SArthur O'Dwyer    constexpr const T&               // constexpr in C++14
585b8bc4e15SArthur O'Dwyer    max(const T& a, const T& b, Compare comp);
5864eb27b79SHoward Hinnant
5874eb27b79SHoward Hinnanttemplate<class T>
588b8bc4e15SArthur O'Dwyer    constexpr T                      // constexpr in C++14
589b8bc4e15SArthur O'Dwyer    max(initializer_list<T> t);
5904eb27b79SHoward Hinnant
5914eb27b79SHoward Hinnanttemplate<class T, class Compare>
592b8bc4e15SArthur O'Dwyer    constexpr T                      // constexpr in C++14
593b8bc4e15SArthur O'Dwyer    max(initializer_list<T> t, Compare comp);
5944eb27b79SHoward Hinnant
5954eb27b79SHoward Hinnanttemplate<class ForwardIterator>
596b8bc4e15SArthur O'Dwyer    constexpr pair<ForwardIterator, ForwardIterator>  // constexpr in C++14
597b8bc4e15SArthur O'Dwyer    minmax_element(ForwardIterator first, ForwardIterator last);
5984eb27b79SHoward Hinnant
5994eb27b79SHoward Hinnanttemplate<class ForwardIterator, class Compare>
600b8bc4e15SArthur O'Dwyer    constexpr pair<ForwardIterator, ForwardIterator>  // constexpr in C++14
601b8bc4e15SArthur O'Dwyer    minmax_element(ForwardIterator first, ForwardIterator last, Compare comp);
6024eb27b79SHoward Hinnant
6034eb27b79SHoward Hinnanttemplate<class T>
604b8bc4e15SArthur O'Dwyer    constexpr pair<const T&, const T&>  // constexpr in C++14
605b8bc4e15SArthur O'Dwyer    minmax(const T& a, const T& b);
6064eb27b79SHoward Hinnant
6074eb27b79SHoward Hinnanttemplate<class T, class Compare>
608b8bc4e15SArthur O'Dwyer    constexpr pair<const T&, const T&>  // constexpr in C++14
609b8bc4e15SArthur O'Dwyer    minmax(const T& a, const T& b, Compare comp);
6104eb27b79SHoward Hinnant
6114eb27b79SHoward Hinnanttemplate<class T>
612b8bc4e15SArthur O'Dwyer    constexpr pair<T, T>                // constexpr in C++14
613b8bc4e15SArthur O'Dwyer    minmax(initializer_list<T> t);
6144eb27b79SHoward Hinnant
6154eb27b79SHoward Hinnanttemplate<class T, class Compare>
616b8bc4e15SArthur O'Dwyer    constexpr pair<T, T>                // constexpr in C++14
617b8bc4e15SArthur O'Dwyer    minmax(initializer_list<T> t, Compare comp);
6184eb27b79SHoward Hinnant
6193e519524SHoward Hinnanttemplate <class InputIterator1, class InputIterator2>
6201b9a4ffdSMarshall Clow    constexpr bool     // constexpr in C++20
6213e519524SHoward Hinnant    lexicographical_compare(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, InputIterator2 last2);
6223e519524SHoward Hinnant
6233e519524SHoward Hinnanttemplate <class InputIterator1, class InputIterator2, class Compare>
6241b9a4ffdSMarshall Clow    constexpr bool     // constexpr in C++20
6253e519524SHoward Hinnant    lexicographical_compare(InputIterator1 first1, InputIterator1 last1,
6263e519524SHoward Hinnant                            InputIterator2 first2, InputIterator2 last2, Compare comp);
6273e519524SHoward Hinnant
6283e519524SHoward Hinnanttemplate <class BidirectionalIterator>
629f851db3dSArthur O'Dwyer    constexpr bool     // constexpr in C++20
6303e519524SHoward Hinnant    next_permutation(BidirectionalIterator first, BidirectionalIterator last);
6313e519524SHoward Hinnant
6323e519524SHoward Hinnanttemplate <class BidirectionalIterator, class Compare>
633f851db3dSArthur O'Dwyer    constexpr bool     // constexpr in C++20
6343e519524SHoward Hinnant    next_permutation(BidirectionalIterator first, BidirectionalIterator last, Compare comp);
6353e519524SHoward Hinnant
6363e519524SHoward Hinnanttemplate <class BidirectionalIterator>
637f851db3dSArthur O'Dwyer    constexpr bool     // constexpr in C++20
6383e519524SHoward Hinnant    prev_permutation(BidirectionalIterator first, BidirectionalIterator last);
6393e519524SHoward Hinnant
6403e519524SHoward Hinnanttemplate <class BidirectionalIterator, class Compare>
641f851db3dSArthur O'Dwyer    constexpr bool     // constexpr in C++20
6423e519524SHoward Hinnant    prev_permutation(BidirectionalIterator first, BidirectionalIterator last, Compare comp);
6433e519524SHoward Hinnant
6443e519524SHoward Hinnant}  // std
6453e519524SHoward Hinnant
6463e519524SHoward Hinnant*/
6473e519524SHoward Hinnant
6483e519524SHoward Hinnant#include <__config>
6493e519524SHoward Hinnant#include <initializer_list>
6503e519524SHoward Hinnant#include <type_traits>
6513e519524SHoward Hinnant#include <cstring>
652f07dd8d0SEric Fiselier#include <utility> // needed to provide swap_ranges.
6533e519524SHoward Hinnant#include <memory>
654d835e592SMarshall Clow#include <functional>
6553e519524SHoward Hinnant#include <iterator>
656a1d07d57SHoward Hinnant#include <cstddef>
657e02ee4f0SMarshall Clow#include <bit>
658f56972e2SMarshall Clow#include <version>
6595d1a701dSHoward Hinnant
660c1bd9197SEric Fiselier#include <__debug>
661c1bd9197SEric Fiselier
662073458b1SHoward Hinnant#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
6633e519524SHoward Hinnant#pragma GCC system_header
664073458b1SHoward Hinnant#endif
6653e519524SHoward Hinnant
666a016efb1SEric Fiselier_LIBCPP_PUSH_MACROS
667a016efb1SEric Fiselier#include <__undef_macros>
668a016efb1SEric Fiselier
669a016efb1SEric Fiselier
6703e519524SHoward Hinnant_LIBCPP_BEGIN_NAMESPACE_STD
6713e519524SHoward Hinnant
6729d67c6d5SMarshall Clow// I'd like to replace these with _VSTD::equal_to<void>, but can't because:
6739d67c6d5SMarshall Clow//   * That only works with C++14 and later, and
6749d67c6d5SMarshall Clow//   * We haven't included <functional> here.
6753e519524SHoward Hinnanttemplate <class _T1, class _T2 = _T1>
6763e519524SHoward Hinnantstruct __equal_to
6773e519524SHoward Hinnant{
678d8098f97SMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 bool operator()(const _T1& __x, const _T1& __y) const {return __x == __y;}
679d8098f97SMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 bool operator()(const _T1& __x, const _T2& __y) const {return __x == __y;}
680d8098f97SMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 bool operator()(const _T2& __x, const _T1& __y) const {return __x == __y;}
681d8098f97SMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 bool operator()(const _T2& __x, const _T2& __y) const {return __x == __y;}
6823e519524SHoward Hinnant};
6833e519524SHoward Hinnant
6843e519524SHoward Hinnanttemplate <class _T1>
6853e519524SHoward Hinnantstruct __equal_to<_T1, _T1>
6863e519524SHoward Hinnant{
6879d67c6d5SMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
6889d67c6d5SMarshall Clow    bool operator()(const _T1& __x, const _T1& __y) const {return __x == __y;}
6893e519524SHoward Hinnant};
6903e519524SHoward Hinnant
6913e519524SHoward Hinnanttemplate <class _T1>
6923e519524SHoward Hinnantstruct __equal_to<const _T1, _T1>
6933e519524SHoward Hinnant{
6949d67c6d5SMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
6959d67c6d5SMarshall Clow    bool operator()(const _T1& __x, const _T1& __y) const {return __x == __y;}
6963e519524SHoward Hinnant};
6973e519524SHoward Hinnant
6983e519524SHoward Hinnanttemplate <class _T1>
6993e519524SHoward Hinnantstruct __equal_to<_T1, const _T1>
7003e519524SHoward Hinnant{
7019d67c6d5SMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
7029d67c6d5SMarshall Clow    bool operator()(const _T1& __x, const _T1& __y) const {return __x == __y;}
7033e519524SHoward Hinnant};
7043e519524SHoward Hinnant
7053e519524SHoward Hinnanttemplate <class _T1, class _T2 = _T1>
7063e519524SHoward Hinnantstruct __less
7073e519524SHoward Hinnant{
7089d67c6d5SMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
7099d67c6d5SMarshall Clow    bool operator()(const _T1& __x, const _T1& __y) const {return __x < __y;}
7109d67c6d5SMarshall Clow
7119d67c6d5SMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
7129d67c6d5SMarshall Clow    bool operator()(const _T1& __x, const _T2& __y) const {return __x < __y;}
7139d67c6d5SMarshall Clow
7149d67c6d5SMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
7159d67c6d5SMarshall Clow    bool operator()(const _T2& __x, const _T1& __y) const {return __x < __y;}
7169d67c6d5SMarshall Clow
7179d67c6d5SMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
7189d67c6d5SMarshall Clow    bool operator()(const _T2& __x, const _T2& __y) const {return __x < __y;}
7193e519524SHoward Hinnant};
7203e519524SHoward Hinnant
7213e519524SHoward Hinnanttemplate <class _T1>
7223e519524SHoward Hinnantstruct __less<_T1, _T1>
7233e519524SHoward Hinnant{
7249d67c6d5SMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
7259d67c6d5SMarshall Clow    bool operator()(const _T1& __x, const _T1& __y) const {return __x < __y;}
7263e519524SHoward Hinnant};
7273e519524SHoward Hinnant
7283e519524SHoward Hinnanttemplate <class _T1>
7293e519524SHoward Hinnantstruct __less<const _T1, _T1>
7303e519524SHoward Hinnant{
7319d67c6d5SMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
7329d67c6d5SMarshall Clow    bool operator()(const _T1& __x, const _T1& __y) const {return __x < __y;}
7333e519524SHoward Hinnant};
7343e519524SHoward Hinnant
7353e519524SHoward Hinnanttemplate <class _T1>
7363e519524SHoward Hinnantstruct __less<_T1, const _T1>
7373e519524SHoward Hinnant{
7389d67c6d5SMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
7399d67c6d5SMarshall Clow    bool operator()(const _T1& __x, const _T1& __y) const {return __x < __y;}
7403e519524SHoward Hinnant};
7413e519524SHoward Hinnant
7423e519524SHoward Hinnanttemplate <class _Predicate>
743a763b36fSMarshall Clowclass __invert // invert the sense of a comparison
7443e519524SHoward Hinnant{
7453e519524SHoward Hinnantprivate:
7463e519524SHoward Hinnant    _Predicate __p_;
7473e519524SHoward Hinnantpublic:
748a763b36fSMarshall Clow    _LIBCPP_INLINE_VISIBILITY __invert() {}
7493e519524SHoward Hinnant
7503e519524SHoward Hinnant    _LIBCPP_INLINE_VISIBILITY
751a763b36fSMarshall Clow    explicit __invert(_Predicate __p) : __p_(__p) {}
7523e519524SHoward Hinnant
7533e519524SHoward Hinnant    template <class _T1>
7543e519524SHoward Hinnant    _LIBCPP_INLINE_VISIBILITY
7553e519524SHoward Hinnant    bool operator()(const _T1& __x) {return !__p_(__x);}
7563e519524SHoward Hinnant
7573e519524SHoward Hinnant    template <class _T1, class _T2>
7583e519524SHoward Hinnant    _LIBCPP_INLINE_VISIBILITY
759a763b36fSMarshall Clow    bool operator()(const _T1& __x, const _T2& __y) {return __p_(__y, __x);}
7603e519524SHoward Hinnant};
7613e519524SHoward Hinnant
76204695a75SLouis Dionne// Perform division by two quickly for positive integers (llvm.org/PR39129)
76304695a75SLouis Dionne
76404695a75SLouis Dionnetemplate <typename _Integral>
76504695a75SLouis Dionne_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
76604695a75SLouis Dionnetypename enable_if
76704695a75SLouis Dionne<
76804695a75SLouis Dionne    is_integral<_Integral>::value,
76904695a75SLouis Dionne    _Integral
77004695a75SLouis Dionne>::type
77104695a75SLouis Dionne__half_positive(_Integral __value)
77204695a75SLouis Dionne{
77304695a75SLouis Dionne    return static_cast<_Integral>(static_cast<typename make_unsigned<_Integral>::type>(__value) / 2);
77404695a75SLouis Dionne}
77504695a75SLouis Dionne
77604695a75SLouis Dionnetemplate <typename _Tp>
77704695a75SLouis Dionne_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
77804695a75SLouis Dionnetypename enable_if
77904695a75SLouis Dionne<
78004695a75SLouis Dionne    !is_integral<_Tp>::value,
78104695a75SLouis Dionne    _Tp
78204695a75SLouis Dionne>::type
78304695a75SLouis Dionne__half_positive(_Tp __value)
78404695a75SLouis Dionne{
78504695a75SLouis Dionne    return __value / 2;
78604695a75SLouis Dionne}
78704695a75SLouis Dionne
788145afa17SHoward Hinnant#ifdef _LIBCPP_DEBUG
7893e519524SHoward Hinnant
7903e519524SHoward Hinnanttemplate <class _Compare>
7913e519524SHoward Hinnantstruct __debug_less
7923e519524SHoward Hinnant{
793aa1cad15SEric Fiselier    _Compare &__comp_;
794aa1cad15SEric Fiselier    _LIBCPP_CONSTEXPR_AFTER_CXX17
7953e519524SHoward Hinnant    __debug_less(_Compare& __c) : __comp_(__c) {}
796331d2159SEric Fiselier
7973e519524SHoward Hinnant    template <class _Tp, class _Up>
7986ab51de0SThomas Anderson    _LIBCPP_CONSTEXPR_AFTER_CXX17
7993c3ccc00SThomas Anderson    bool operator()(const _Tp& __x,  const _Up& __y)
8003c3ccc00SThomas Anderson    {
8013c3ccc00SThomas Anderson        bool __r = __comp_(__x, __y);
8023c3ccc00SThomas Anderson        if (__r)
8033c3ccc00SThomas Anderson            __do_compare_assert(0, __y, __x);
8043c3ccc00SThomas Anderson        return __r;
8053c3ccc00SThomas Anderson    }
8063c3ccc00SThomas Anderson
8073c3ccc00SThomas Anderson    template <class _Tp, class _Up>
808aa1cad15SEric Fiselier    _LIBCPP_CONSTEXPR_AFTER_CXX17
8096e4ec602SEric Fiselier    bool operator()(_Tp& __x,  _Up& __y)
8103e519524SHoward Hinnant    {
8113e519524SHoward Hinnant        bool __r = __comp_(__x, __y);
8123e519524SHoward Hinnant        if (__r)
813331d2159SEric Fiselier            __do_compare_assert(0, __y, __x);
8143e519524SHoward Hinnant        return __r;
8153e519524SHoward Hinnant    }
816331d2159SEric Fiselier
817331d2159SEric Fiselier    template <class _LHS, class _RHS>
818aa1cad15SEric Fiselier    _LIBCPP_CONSTEXPR_AFTER_CXX17
819331d2159SEric Fiselier    inline _LIBCPP_INLINE_VISIBILITY
820331d2159SEric Fiselier    decltype((void)_VSTD::declval<_Compare&>()(
8216e4ec602SEric Fiselier        _VSTD::declval<_LHS &>(), _VSTD::declval<_RHS &>()))
8226e4ec602SEric Fiselier    __do_compare_assert(int, _LHS & __l, _RHS & __r) {
823331d2159SEric Fiselier        _LIBCPP_ASSERT(!__comp_(__l, __r),
824331d2159SEric Fiselier            "Comparator does not induce a strict weak ordering");
825331d2159SEric Fiselier    }
826331d2159SEric Fiselier
827331d2159SEric Fiselier    template <class _LHS, class _RHS>
828aa1cad15SEric Fiselier    _LIBCPP_CONSTEXPR_AFTER_CXX17
829331d2159SEric Fiselier    inline _LIBCPP_INLINE_VISIBILITY
8306e4ec602SEric Fiselier    void __do_compare_assert(long, _LHS &, _RHS &) {}
8313e519524SHoward Hinnant};
8323e519524SHoward Hinnant
833145afa17SHoward Hinnant#endif // _LIBCPP_DEBUG
8343e519524SHoward Hinnant
835aa1cad15SEric Fiseliertemplate <class _Comp>
836aa1cad15SEric Fiselierstruct __comp_ref_type {
837aa1cad15SEric Fiselier  // Pass the comparator by lvalue reference. Or in debug mode, using a
838aa1cad15SEric Fiselier  // debugging wrapper that stores a reference.
839aa1cad15SEric Fiselier#ifndef _LIBCPP_DEBUG
840aa1cad15SEric Fiselier  typedef typename add_lvalue_reference<_Comp>::type type;
841aa1cad15SEric Fiselier#else
842aa1cad15SEric Fiselier  typedef __debug_less<_Comp> type;
843aa1cad15SEric Fiselier#endif
844aa1cad15SEric Fiselier};
845aa1cad15SEric Fiselier
8463e519524SHoward Hinnant// all_of
8473e519524SHoward Hinnant
8483e519524SHoward Hinnanttemplate <class _InputIterator, class _Predicate>
8491362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
8501362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
8513e519524SHoward Hinnantbool
8523e519524SHoward Hinnantall_of(_InputIterator __first, _InputIterator __last, _Predicate __pred)
8533e519524SHoward Hinnant{
8543e519524SHoward Hinnant    for (; __first != __last; ++__first)
8553e519524SHoward Hinnant        if (!__pred(*__first))
8563e519524SHoward Hinnant            return false;
8573e519524SHoward Hinnant    return true;
8583e519524SHoward Hinnant}
8593e519524SHoward Hinnant
8603e519524SHoward Hinnant// any_of
8613e519524SHoward Hinnant
8623e519524SHoward Hinnanttemplate <class _InputIterator, class _Predicate>
8631362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
8641362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
8653e519524SHoward Hinnantbool
8663e519524SHoward Hinnantany_of(_InputIterator __first, _InputIterator __last, _Predicate __pred)
8673e519524SHoward Hinnant{
8683e519524SHoward Hinnant    for (; __first != __last; ++__first)
8693e519524SHoward Hinnant        if (__pred(*__first))
8703e519524SHoward Hinnant            return true;
8713e519524SHoward Hinnant    return false;
8723e519524SHoward Hinnant}
8733e519524SHoward Hinnant
8743e519524SHoward Hinnant// none_of
8753e519524SHoward Hinnant
8763e519524SHoward Hinnanttemplate <class _InputIterator, class _Predicate>
8771362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
8781362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
8793e519524SHoward Hinnantbool
8803e519524SHoward Hinnantnone_of(_InputIterator __first, _InputIterator __last, _Predicate __pred)
8813e519524SHoward Hinnant{
8823e519524SHoward Hinnant    for (; __first != __last; ++__first)
8833e519524SHoward Hinnant        if (__pred(*__first))
8843e519524SHoward Hinnant            return false;
8853e519524SHoward Hinnant    return true;
8863e519524SHoward Hinnant}
8873e519524SHoward Hinnant
8883e519524SHoward Hinnant// for_each
8893e519524SHoward Hinnant
8903e519524SHoward Hinnanttemplate <class _InputIterator, class _Function>
8911b9a4ffdSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
8923e519524SHoward Hinnant_Function
8933e519524SHoward Hinnantfor_each(_InputIterator __first, _InputIterator __last, _Function __f)
8943e519524SHoward Hinnant{
8953e519524SHoward Hinnant    for (; __first != __last; ++__first)
8963e519524SHoward Hinnant        __f(*__first);
8971c7fe126SMarshall Clow    return __f;
8983e519524SHoward Hinnant}
8993e519524SHoward Hinnant
9001d02996dSMarshall Clow#if _LIBCPP_STD_VER > 14
901d5c65ffaSMarshall Clow// for_each_n
902d5c65ffaSMarshall Clow
903d5c65ffaSMarshall Clowtemplate <class _InputIterator, class _Size, class _Function>
9041b9a4ffdSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
905d5c65ffaSMarshall Clow_InputIterator
906d5c65ffaSMarshall Clowfor_each_n(_InputIterator __first, _Size __orig_n, _Function __f)
907d5c65ffaSMarshall Clow{
908c0428b3cSArthur O'Dwyer    typedef decltype(_VSTD::__convert_to_integral(__orig_n)) _IntegralSize;
909d5c65ffaSMarshall Clow    _IntegralSize __n = __orig_n;
910d5c65ffaSMarshall Clow    while (__n > 0)
911d5c65ffaSMarshall Clow    {
912d5c65ffaSMarshall Clow         __f(*__first);
913d5c65ffaSMarshall Clow         ++__first;
914d5c65ffaSMarshall Clow         --__n;
915d5c65ffaSMarshall Clow    }
916d5c65ffaSMarshall Clow    return __first;
917d5c65ffaSMarshall Clow}
9181d02996dSMarshall Clow#endif
919d5c65ffaSMarshall Clow
9203e519524SHoward Hinnant// find
9213e519524SHoward Hinnant
9223e519524SHoward Hinnanttemplate <class _InputIterator, class _Tp>
9231362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
9241362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
9253e519524SHoward Hinnant_InputIterator
926e4383379SHoward Hinnantfind(_InputIterator __first, _InputIterator __last, const _Tp& __value_)
9273e519524SHoward Hinnant{
9283e519524SHoward Hinnant    for (; __first != __last; ++__first)
929e4383379SHoward Hinnant        if (*__first == __value_)
9303e519524SHoward Hinnant            break;
9313e519524SHoward Hinnant    return __first;
9323e519524SHoward Hinnant}
9333e519524SHoward Hinnant
9343e519524SHoward Hinnant// find_if
9353e519524SHoward Hinnant
9363e519524SHoward Hinnanttemplate <class _InputIterator, class _Predicate>
9371362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
9381362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
9393e519524SHoward Hinnant_InputIterator
9403e519524SHoward Hinnantfind_if(_InputIterator __first, _InputIterator __last, _Predicate __pred)
9413e519524SHoward Hinnant{
9423e519524SHoward Hinnant    for (; __first != __last; ++__first)
9433e519524SHoward Hinnant        if (__pred(*__first))
9443e519524SHoward Hinnant            break;
9453e519524SHoward Hinnant    return __first;
9463e519524SHoward Hinnant}
9473e519524SHoward Hinnant
9483e519524SHoward Hinnant// find_if_not
9493e519524SHoward Hinnant
9503e519524SHoward Hinnanttemplate<class _InputIterator, class _Predicate>
9511362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
9521362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
9533e519524SHoward Hinnant_InputIterator
9543e519524SHoward Hinnantfind_if_not(_InputIterator __first, _InputIterator __last, _Predicate __pred)
9553e519524SHoward Hinnant{
9563e519524SHoward Hinnant    for (; __first != __last; ++__first)
9573e519524SHoward Hinnant        if (!__pred(*__first))
9583e519524SHoward Hinnant            break;
9593e519524SHoward Hinnant    return __first;
9603e519524SHoward Hinnant}
9613e519524SHoward Hinnant
9623e519524SHoward Hinnant// find_end
9633e519524SHoward Hinnant
9643e519524SHoward Hinnanttemplate <class _BinaryPredicate, class _ForwardIterator1, class _ForwardIterator2>
9658694428eSMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator1
9663e519524SHoward Hinnant__find_end(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
9673e519524SHoward Hinnant           _ForwardIterator2 __first2, _ForwardIterator2 __last2, _BinaryPredicate __pred,
9683e519524SHoward Hinnant           forward_iterator_tag, forward_iterator_tag)
9693e519524SHoward Hinnant{
9703e519524SHoward Hinnant    // modeled after search algorithm
9713e519524SHoward Hinnant    _ForwardIterator1 __r = __last1;  // __last1 is the "default" answer
9723e519524SHoward Hinnant    if (__first2 == __last2)
9733e519524SHoward Hinnant        return __r;
9743e519524SHoward Hinnant    while (true)
9753e519524SHoward Hinnant    {
9763e519524SHoward Hinnant        while (true)
9773e519524SHoward Hinnant        {
9783e519524SHoward Hinnant            if (__first1 == __last1)         // if source exhausted return last correct answer
9793e519524SHoward Hinnant                return __r;                  //    (or __last1 if never found)
9803e519524SHoward Hinnant            if (__pred(*__first1, *__first2))
9813e519524SHoward Hinnant                break;
9823e519524SHoward Hinnant            ++__first1;
9833e519524SHoward Hinnant        }
9843e519524SHoward Hinnant        // *__first1 matches *__first2, now match elements after here
9853e519524SHoward Hinnant        _ForwardIterator1 __m1 = __first1;
9863e519524SHoward Hinnant        _ForwardIterator2 __m2 = __first2;
9873e519524SHoward Hinnant        while (true)
9883e519524SHoward Hinnant        {
9893e519524SHoward Hinnant            if (++__m2 == __last2)
9903e519524SHoward Hinnant            {                         // Pattern exhaused, record answer and search for another one
9913e519524SHoward Hinnant                __r = __first1;
9923e519524SHoward Hinnant                ++__first1;
9933e519524SHoward Hinnant                break;
9943e519524SHoward Hinnant            }
9953e519524SHoward Hinnant            if (++__m1 == __last1)     // Source exhausted, return last answer
9963e519524SHoward Hinnant                return __r;
9973e519524SHoward Hinnant            if (!__pred(*__m1, *__m2))  // mismatch, restart with a new __first
9983e519524SHoward Hinnant            {
9993e519524SHoward Hinnant                ++__first1;
10003e519524SHoward Hinnant                break;
10013e519524SHoward Hinnant            }  // else there is a match, check next elements
10023e519524SHoward Hinnant        }
10033e519524SHoward Hinnant    }
10043e519524SHoward Hinnant}
10053e519524SHoward Hinnant
10063e519524SHoward Hinnanttemplate <class _BinaryPredicate, class _BidirectionalIterator1, class _BidirectionalIterator2>
10078694428eSMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 _BidirectionalIterator1
10083e519524SHoward Hinnant__find_end(_BidirectionalIterator1 __first1, _BidirectionalIterator1 __last1,
10093e519524SHoward Hinnant           _BidirectionalIterator2 __first2, _BidirectionalIterator2 __last2, _BinaryPredicate __pred,
10103e519524SHoward Hinnant           bidirectional_iterator_tag, bidirectional_iterator_tag)
10113e519524SHoward Hinnant{
10123e519524SHoward Hinnant    // modeled after search algorithm (in reverse)
10133e519524SHoward Hinnant    if (__first2 == __last2)
10143e519524SHoward Hinnant        return __last1;  // Everything matches an empty sequence
10153e519524SHoward Hinnant    _BidirectionalIterator1 __l1 = __last1;
10163e519524SHoward Hinnant    _BidirectionalIterator2 __l2 = __last2;
10173e519524SHoward Hinnant    --__l2;
10183e519524SHoward Hinnant    while (true)
10193e519524SHoward Hinnant    {
10203e519524SHoward Hinnant        // Find last element in sequence 1 that matchs *(__last2-1), with a mininum of loop checks
10213e519524SHoward Hinnant        while (true)
10223e519524SHoward Hinnant        {
10233e519524SHoward Hinnant            if (__first1 == __l1)  // return __last1 if no element matches *__first2
10243e519524SHoward Hinnant                return __last1;
10253e519524SHoward Hinnant            if (__pred(*--__l1, *__l2))
10263e519524SHoward Hinnant                break;
10273e519524SHoward Hinnant        }
10283e519524SHoward Hinnant        // *__l1 matches *__l2, now match elements before here
10293e519524SHoward Hinnant        _BidirectionalIterator1 __m1 = __l1;
10303e519524SHoward Hinnant        _BidirectionalIterator2 __m2 = __l2;
10313e519524SHoward Hinnant        while (true)
10323e519524SHoward Hinnant        {
10333e519524SHoward Hinnant            if (__m2 == __first2)  // If pattern exhausted, __m1 is the answer (works for 1 element pattern)
10343e519524SHoward Hinnant                return __m1;
10353e519524SHoward Hinnant            if (__m1 == __first1)  // Otherwise if source exhaused, pattern not found
10363e519524SHoward Hinnant                return __last1;
10373e519524SHoward Hinnant            if (!__pred(*--__m1, *--__m2))  // if there is a mismatch, restart with a new __l1
10383e519524SHoward Hinnant            {
10393e519524SHoward Hinnant                break;
10403e519524SHoward Hinnant            }  // else there is a match, check next elements
10413e519524SHoward Hinnant        }
10423e519524SHoward Hinnant    }
10433e519524SHoward Hinnant}
10443e519524SHoward Hinnant
10453e519524SHoward Hinnanttemplate <class _BinaryPredicate, class _RandomAccessIterator1, class _RandomAccessIterator2>
10469b0af34dSMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX11 _RandomAccessIterator1
10473e519524SHoward Hinnant__find_end(_RandomAccessIterator1 __first1, _RandomAccessIterator1 __last1,
10483e519524SHoward Hinnant           _RandomAccessIterator2 __first2, _RandomAccessIterator2 __last2, _BinaryPredicate __pred,
10493e519524SHoward Hinnant           random_access_iterator_tag, random_access_iterator_tag)
10503e519524SHoward Hinnant{
10513e519524SHoward Hinnant    // Take advantage of knowing source and pattern lengths.  Stop short when source is smaller than pattern
10523e519524SHoward Hinnant    typename iterator_traits<_RandomAccessIterator2>::difference_type __len2 = __last2 - __first2;
10533e519524SHoward Hinnant    if (__len2 == 0)
10543e519524SHoward Hinnant        return __last1;
10553e519524SHoward Hinnant    typename iterator_traits<_RandomAccessIterator1>::difference_type __len1 = __last1 - __first1;
10563e519524SHoward Hinnant    if (__len1 < __len2)
10573e519524SHoward Hinnant        return __last1;
10583e519524SHoward Hinnant    const _RandomAccessIterator1 __s = __first1 + (__len2 - 1);  // End of pattern match can't go before here
10593e519524SHoward Hinnant    _RandomAccessIterator1 __l1 = __last1;
10603e519524SHoward Hinnant    _RandomAccessIterator2 __l2 = __last2;
10613e519524SHoward Hinnant    --__l2;
10623e519524SHoward Hinnant    while (true)
10633e519524SHoward Hinnant    {
10643e519524SHoward Hinnant        while (true)
10653e519524SHoward Hinnant        {
10663e519524SHoward Hinnant            if (__s == __l1)
10673e519524SHoward Hinnant                return __last1;
10683e519524SHoward Hinnant            if (__pred(*--__l1, *__l2))
10693e519524SHoward Hinnant                break;
10703e519524SHoward Hinnant        }
10713e519524SHoward Hinnant        _RandomAccessIterator1 __m1 = __l1;
10723e519524SHoward Hinnant        _RandomAccessIterator2 __m2 = __l2;
10733e519524SHoward Hinnant        while (true)
10743e519524SHoward Hinnant        {
10753e519524SHoward Hinnant            if (__m2 == __first2)
10763e519524SHoward Hinnant                return __m1;
10773e519524SHoward Hinnant                                 // no need to check range on __m1 because __s guarantees we have enough source
10783e519524SHoward Hinnant            if (!__pred(*--__m1, *--__m2))
10793e519524SHoward Hinnant            {
10803e519524SHoward Hinnant                break;
10813e519524SHoward Hinnant            }
10823e519524SHoward Hinnant        }
10833e519524SHoward Hinnant    }
10843e519524SHoward Hinnant}
10853e519524SHoward Hinnant
10863e519524SHoward Hinnanttemplate <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
10871362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
10881362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
10893e519524SHoward Hinnant_ForwardIterator1
10903e519524SHoward Hinnantfind_end(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
10913e519524SHoward Hinnant         _ForwardIterator2 __first2, _ForwardIterator2 __last2, _BinaryPredicate __pred)
10923e519524SHoward Hinnant{
1093ce48a113SHoward Hinnant    return _VSTD::__find_end<typename add_lvalue_reference<_BinaryPredicate>::type>
10943e519524SHoward Hinnant                         (__first1, __last1, __first2, __last2, __pred,
10953e519524SHoward Hinnant                          typename iterator_traits<_ForwardIterator1>::iterator_category(),
10963e519524SHoward Hinnant                          typename iterator_traits<_ForwardIterator2>::iterator_category());
10973e519524SHoward Hinnant}
10983e519524SHoward Hinnant
10993e519524SHoward Hinnanttemplate <class _ForwardIterator1, class _ForwardIterator2>
11001362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
11011362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
11023e519524SHoward Hinnant_ForwardIterator1
11033e519524SHoward Hinnantfind_end(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
11043e519524SHoward Hinnant         _ForwardIterator2 __first2, _ForwardIterator2 __last2)
11053e519524SHoward Hinnant{
11063e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator1>::value_type __v1;
11073e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator2>::value_type __v2;
1108ce48a113SHoward Hinnant    return _VSTD::find_end(__first1, __last1, __first2, __last2, __equal_to<__v1, __v2>());
11093e519524SHoward Hinnant}
11103e519524SHoward Hinnant
11113e519524SHoward Hinnant// find_first_of
11123e519524SHoward Hinnant
11133e519524SHoward Hinnanttemplate <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
11149b0af34dSMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX11 _ForwardIterator1
11159b0af34dSMarshall Clow__find_first_of_ce(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
11163e519524SHoward Hinnant              _ForwardIterator2 __first2, _ForwardIterator2 __last2, _BinaryPredicate __pred)
11173e519524SHoward Hinnant{
11183e519524SHoward Hinnant    for (; __first1 != __last1; ++__first1)
11193e519524SHoward Hinnant        for (_ForwardIterator2 __j = __first2; __j != __last2; ++__j)
11203e519524SHoward Hinnant            if (__pred(*__first1, *__j))
11213e519524SHoward Hinnant                return __first1;
11223e519524SHoward Hinnant    return __last1;
11233e519524SHoward Hinnant}
11243e519524SHoward Hinnant
11259b0af34dSMarshall Clow
11269b0af34dSMarshall Clowtemplate <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
11271362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
11281362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
11299b0af34dSMarshall Clow_ForwardIterator1
11309b0af34dSMarshall Clowfind_first_of(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
11319b0af34dSMarshall Clow              _ForwardIterator2 __first2, _ForwardIterator2 __last2, _BinaryPredicate __pred)
11329b0af34dSMarshall Clow{
11339b0af34dSMarshall Clow    return _VSTD::__find_first_of_ce(__first1, __last1, __first2, __last2, __pred);
11349b0af34dSMarshall Clow}
11359b0af34dSMarshall Clow
11363e519524SHoward Hinnanttemplate <class _ForwardIterator1, class _ForwardIterator2>
11371362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
11381362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
11393e519524SHoward Hinnant_ForwardIterator1
11403e519524SHoward Hinnantfind_first_of(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
11413e519524SHoward Hinnant              _ForwardIterator2 __first2, _ForwardIterator2 __last2)
11423e519524SHoward Hinnant{
11433e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator1>::value_type __v1;
11443e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator2>::value_type __v2;
11459b0af34dSMarshall Clow    return _VSTD::__find_first_of_ce(__first1, __last1, __first2, __last2, __equal_to<__v1, __v2>());
11463e519524SHoward Hinnant}
11473e519524SHoward Hinnant
11483e519524SHoward Hinnant// adjacent_find
11493e519524SHoward Hinnant
11503e519524SHoward Hinnanttemplate <class _ForwardIterator, class _BinaryPredicate>
11511362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
11521362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
11533e519524SHoward Hinnant_ForwardIterator
11543e519524SHoward Hinnantadjacent_find(_ForwardIterator __first, _ForwardIterator __last, _BinaryPredicate __pred)
11553e519524SHoward Hinnant{
11563e519524SHoward Hinnant    if (__first != __last)
11573e519524SHoward Hinnant    {
11583e519524SHoward Hinnant        _ForwardIterator __i = __first;
11593e519524SHoward Hinnant        while (++__i != __last)
11603e519524SHoward Hinnant        {
11613e519524SHoward Hinnant            if (__pred(*__first, *__i))
11623e519524SHoward Hinnant                return __first;
11633e519524SHoward Hinnant            __first = __i;
11643e519524SHoward Hinnant        }
11653e519524SHoward Hinnant    }
11663e519524SHoward Hinnant    return __last;
11673e519524SHoward Hinnant}
11683e519524SHoward Hinnant
11693e519524SHoward Hinnanttemplate <class _ForwardIterator>
11701362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
11711362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
11723e519524SHoward Hinnant_ForwardIterator
11733e519524SHoward Hinnantadjacent_find(_ForwardIterator __first, _ForwardIterator __last)
11743e519524SHoward Hinnant{
11753e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator>::value_type __v;
1176ce48a113SHoward Hinnant    return _VSTD::adjacent_find(__first, __last, __equal_to<__v>());
11773e519524SHoward Hinnant}
11783e519524SHoward Hinnant
11793e519524SHoward Hinnant// count
11803e519524SHoward Hinnant
11813e519524SHoward Hinnanttemplate <class _InputIterator, class _Tp>
11821362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
11831362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
11843e519524SHoward Hinnanttypename iterator_traits<_InputIterator>::difference_type
1185e4383379SHoward Hinnantcount(_InputIterator __first, _InputIterator __last, const _Tp& __value_)
11863e519524SHoward Hinnant{
11873e519524SHoward Hinnant    typename iterator_traits<_InputIterator>::difference_type __r(0);
11883e519524SHoward Hinnant    for (; __first != __last; ++__first)
1189e4383379SHoward Hinnant        if (*__first == __value_)
11903e519524SHoward Hinnant            ++__r;
11913e519524SHoward Hinnant    return __r;
11923e519524SHoward Hinnant}
11933e519524SHoward Hinnant
11943e519524SHoward Hinnant// count_if
11953e519524SHoward Hinnant
11963e519524SHoward Hinnanttemplate <class _InputIterator, class _Predicate>
11971362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
11981362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
11993e519524SHoward Hinnanttypename iterator_traits<_InputIterator>::difference_type
12003e519524SHoward Hinnantcount_if(_InputIterator __first, _InputIterator __last, _Predicate __pred)
12013e519524SHoward Hinnant{
12023e519524SHoward Hinnant    typename iterator_traits<_InputIterator>::difference_type __r(0);
12033e519524SHoward Hinnant    for (; __first != __last; ++__first)
12043e519524SHoward Hinnant        if (__pred(*__first))
12053e519524SHoward Hinnant            ++__r;
12063e519524SHoward Hinnant    return __r;
12073e519524SHoward Hinnant}
12083e519524SHoward Hinnant
12093e519524SHoward Hinnant// mismatch
12103e519524SHoward Hinnant
12113e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
12121362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
12131362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
12143e519524SHoward Hinnantpair<_InputIterator1, _InputIterator2>
12153e519524SHoward Hinnantmismatch(_InputIterator1 __first1, _InputIterator1 __last1,
12163e519524SHoward Hinnant         _InputIterator2 __first2, _BinaryPredicate __pred)
12173e519524SHoward Hinnant{
1218bd7c7b55SMarshall Clow    for (; __first1 != __last1; ++__first1, (void) ++__first2)
12193e519524SHoward Hinnant        if (!__pred(*__first1, *__first2))
12203e519524SHoward Hinnant            break;
12213e519524SHoward Hinnant    return pair<_InputIterator1, _InputIterator2>(__first1, __first2);
12223e519524SHoward Hinnant}
12233e519524SHoward Hinnant
12243e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2>
12251362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
12261362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
12273e519524SHoward Hinnantpair<_InputIterator1, _InputIterator2>
12283e519524SHoward Hinnantmismatch(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2)
12293e519524SHoward Hinnant{
12303e519524SHoward Hinnant    typedef typename iterator_traits<_InputIterator1>::value_type __v1;
12313e519524SHoward Hinnant    typedef typename iterator_traits<_InputIterator2>::value_type __v2;
1232ce48a113SHoward Hinnant    return _VSTD::mismatch(__first1, __last1, __first2, __equal_to<__v1, __v2>());
12333e519524SHoward Hinnant}
12343e519524SHoward Hinnant
12350b0bbd2fSMarshall Clow#if _LIBCPP_STD_VER > 11
12360b0bbd2fSMarshall Clowtemplate <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
12371362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
12381362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
12390b0bbd2fSMarshall Clowpair<_InputIterator1, _InputIterator2>
12400b0bbd2fSMarshall Clowmismatch(_InputIterator1 __first1, _InputIterator1 __last1,
12410b0bbd2fSMarshall Clow         _InputIterator2 __first2, _InputIterator2 __last2,
12420b0bbd2fSMarshall Clow         _BinaryPredicate __pred)
12430b0bbd2fSMarshall Clow{
1244bd7c7b55SMarshall Clow    for (; __first1 != __last1 && __first2 != __last2; ++__first1, (void) ++__first2)
12450b0bbd2fSMarshall Clow        if (!__pred(*__first1, *__first2))
12460b0bbd2fSMarshall Clow            break;
12470b0bbd2fSMarshall Clow    return pair<_InputIterator1, _InputIterator2>(__first1, __first2);
12480b0bbd2fSMarshall Clow}
12490b0bbd2fSMarshall Clow
12500b0bbd2fSMarshall Clowtemplate <class _InputIterator1, class _InputIterator2>
12511362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
12521362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
12530b0bbd2fSMarshall Clowpair<_InputIterator1, _InputIterator2>
12540b0bbd2fSMarshall Clowmismatch(_InputIterator1 __first1, _InputIterator1 __last1,
12550b0bbd2fSMarshall Clow         _InputIterator2 __first2, _InputIterator2 __last2)
12560b0bbd2fSMarshall Clow{
12570b0bbd2fSMarshall Clow    typedef typename iterator_traits<_InputIterator1>::value_type __v1;
12580b0bbd2fSMarshall Clow    typedef typename iterator_traits<_InputIterator2>::value_type __v2;
12590b0bbd2fSMarshall Clow    return _VSTD::mismatch(__first1, __last1, __first2, __last2, __equal_to<__v1, __v2>());
12600b0bbd2fSMarshall Clow}
12610b0bbd2fSMarshall Clow#endif
12620b0bbd2fSMarshall Clow
12633e519524SHoward Hinnant// equal
12643e519524SHoward Hinnant
12653e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
12661362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
12671362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
12683e519524SHoward Hinnantbool
12693e519524SHoward Hinnantequal(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _BinaryPredicate __pred)
12703e519524SHoward Hinnant{
1271910285b2SEric Fiselier    for (; __first1 != __last1; ++__first1, (void) ++__first2)
12723e519524SHoward Hinnant        if (!__pred(*__first1, *__first2))
12733e519524SHoward Hinnant            return false;
12743e519524SHoward Hinnant    return true;
12753e519524SHoward Hinnant}
12763e519524SHoward Hinnant
12773e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2>
12781362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
12791362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
12803e519524SHoward Hinnantbool
12813e519524SHoward Hinnantequal(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2)
12823e519524SHoward Hinnant{
12833e519524SHoward Hinnant    typedef typename iterator_traits<_InputIterator1>::value_type __v1;
12843e519524SHoward Hinnant    typedef typename iterator_traits<_InputIterator2>::value_type __v2;
1285ce48a113SHoward Hinnant    return _VSTD::equal(__first1, __last1, __first2, __equal_to<__v1, __v2>());
12863e519524SHoward Hinnant}
12873e519524SHoward Hinnant
12880b0bbd2fSMarshall Clow#if _LIBCPP_STD_VER > 11
12890b0bbd2fSMarshall Clowtemplate <class _BinaryPredicate, class _InputIterator1, class _InputIterator2>
12906538e28dSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
12910b0bbd2fSMarshall Clowbool
12920b0bbd2fSMarshall Clow__equal(_InputIterator1 __first1, _InputIterator1 __last1,
12930b0bbd2fSMarshall Clow        _InputIterator2 __first2, _InputIterator2 __last2, _BinaryPredicate __pred,
12940b0bbd2fSMarshall Clow        input_iterator_tag, input_iterator_tag )
12950b0bbd2fSMarshall Clow{
1296910285b2SEric Fiselier    for (; __first1 != __last1 && __first2 != __last2; ++__first1, (void) ++__first2)
12970b0bbd2fSMarshall Clow        if (!__pred(*__first1, *__first2))
12980b0bbd2fSMarshall Clow            return false;
12990b0bbd2fSMarshall Clow    return __first1 == __last1 && __first2 == __last2;
13000b0bbd2fSMarshall Clow}
13010b0bbd2fSMarshall Clow
13020b0bbd2fSMarshall Clowtemplate <class _BinaryPredicate, class _RandomAccessIterator1, class _RandomAccessIterator2>
13036538e28dSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
13040b0bbd2fSMarshall Clowbool
13050b0bbd2fSMarshall Clow__equal(_RandomAccessIterator1 __first1, _RandomAccessIterator1 __last1,
13060b0bbd2fSMarshall Clow        _RandomAccessIterator2 __first2, _RandomAccessIterator2 __last2, _BinaryPredicate __pred,
13070b0bbd2fSMarshall Clow      random_access_iterator_tag, random_access_iterator_tag )
13080b0bbd2fSMarshall Clow{
13090b0bbd2fSMarshall Clow    if ( _VSTD::distance(__first1, __last1) != _VSTD::distance(__first2, __last2))
13100b0bbd2fSMarshall Clow        return false;
13110b0bbd2fSMarshall Clow    return _VSTD::equal<_RandomAccessIterator1, _RandomAccessIterator2,
13120b0bbd2fSMarshall Clow                        typename add_lvalue_reference<_BinaryPredicate>::type>
13130b0bbd2fSMarshall Clow                       (__first1, __last1, __first2, __pred );
13140b0bbd2fSMarshall Clow}
13150b0bbd2fSMarshall Clow
13160b0bbd2fSMarshall Clowtemplate <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
13171362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
13181362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
13190b0bbd2fSMarshall Clowbool
13200b0bbd2fSMarshall Clowequal(_InputIterator1 __first1, _InputIterator1 __last1,
13210b0bbd2fSMarshall Clow      _InputIterator2 __first2, _InputIterator2 __last2, _BinaryPredicate __pred )
13220b0bbd2fSMarshall Clow{
13230b0bbd2fSMarshall Clow    return _VSTD::__equal<typename add_lvalue_reference<_BinaryPredicate>::type>
13240b0bbd2fSMarshall Clow       (__first1, __last1, __first2, __last2, __pred,
13250b0bbd2fSMarshall Clow        typename iterator_traits<_InputIterator1>::iterator_category(),
13260b0bbd2fSMarshall Clow        typename iterator_traits<_InputIterator2>::iterator_category());
13270b0bbd2fSMarshall Clow}
13280b0bbd2fSMarshall Clow
13290b0bbd2fSMarshall Clowtemplate <class _InputIterator1, class _InputIterator2>
13301362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
13311362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
13320b0bbd2fSMarshall Clowbool
13330b0bbd2fSMarshall Clowequal(_InputIterator1 __first1, _InputIterator1 __last1,
13340b0bbd2fSMarshall Clow      _InputIterator2 __first2, _InputIterator2 __last2)
13350b0bbd2fSMarshall Clow{
13360b0bbd2fSMarshall Clow    typedef typename iterator_traits<_InputIterator1>::value_type __v1;
13370b0bbd2fSMarshall Clow    typedef typename iterator_traits<_InputIterator2>::value_type __v2;
13380b0bbd2fSMarshall Clow    return _VSTD::__equal(__first1, __last1, __first2, __last2, __equal_to<__v1, __v2>(),
13390b0bbd2fSMarshall Clow        typename iterator_traits<_InputIterator1>::iterator_category(),
13400b0bbd2fSMarshall Clow        typename iterator_traits<_InputIterator2>::iterator_category());
13410b0bbd2fSMarshall Clow}
13420b0bbd2fSMarshall Clow#endif
13430b0bbd2fSMarshall Clow
13443e519524SHoward Hinnant// is_permutation
13453e519524SHoward Hinnant
13463e519524SHoward Hinnanttemplate<class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
13471362d7efSNico Weber_LIBCPP_NODISCARD_EXT _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
13483e519524SHoward Hinnantis_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
13493e519524SHoward Hinnant               _ForwardIterator2 __first2, _BinaryPredicate __pred)
13503e519524SHoward Hinnant{
135149c7643cSMarshall Clow//  shorten sequences as much as possible by lopping of any equal prefix
1352910285b2SEric Fiselier    for (; __first1 != __last1; ++__first1, (void) ++__first2)
13533e519524SHoward Hinnant        if (!__pred(*__first1, *__first2))
135449c7643cSMarshall Clow            break;
135549c7643cSMarshall Clow    if (__first1 == __last1)
13563e519524SHoward Hinnant        return true;
135749c7643cSMarshall Clow
13583e519524SHoward Hinnant//  __first1 != __last1 && *__first1 != *__first2
13593e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator1>::difference_type _D1;
1360ce48a113SHoward Hinnant    _D1 __l1 = _VSTD::distance(__first1, __last1);
13613e519524SHoward Hinnant    if (__l1 == _D1(1))
13623e519524SHoward Hinnant        return false;
1363ce48a113SHoward Hinnant    _ForwardIterator2 __last2 = _VSTD::next(__first2, __l1);
13643e519524SHoward Hinnant    // For each element in [f1, l1) see if there are the same number of
13653e519524SHoward Hinnant    //    equal elements in [f2, l2)
13663e519524SHoward Hinnant    for (_ForwardIterator1 __i = __first1; __i != __last1; ++__i)
13673e519524SHoward Hinnant    {
13683e519524SHoward Hinnant    //  Have we already counted the number of *__i in [f1, l1)?
1369939b1623SPeter Collingbourne        _ForwardIterator1 __match = __first1;
1370939b1623SPeter Collingbourne        for (; __match != __i; ++__match)
1371939b1623SPeter Collingbourne            if (__pred(*__match, *__i))
1372939b1623SPeter Collingbourne                break;
1373939b1623SPeter Collingbourne        if (__match == __i) {
13743e519524SHoward Hinnant            // Count number of *__i in [f2, l2)
13753e519524SHoward Hinnant            _D1 __c2 = 0;
13763e519524SHoward Hinnant            for (_ForwardIterator2 __j = __first2; __j != __last2; ++__j)
13773e519524SHoward Hinnant                if (__pred(*__i, *__j))
13783e519524SHoward Hinnant                    ++__c2;
13793e519524SHoward Hinnant            if (__c2 == 0)
13803e519524SHoward Hinnant                return false;
13813e519524SHoward Hinnant            // Count number of *__i in [__i, l1) (we can start with 1)
13823e519524SHoward Hinnant            _D1 __c1 = 1;
1383ce48a113SHoward Hinnant            for (_ForwardIterator1 __j = _VSTD::next(__i); __j != __last1; ++__j)
13843e519524SHoward Hinnant                if (__pred(*__i, *__j))
13853e519524SHoward Hinnant                    ++__c1;
13863e519524SHoward Hinnant            if (__c1 != __c2)
13873e519524SHoward Hinnant                return false;
13883e519524SHoward Hinnant        }
13893e519524SHoward Hinnant    }
13903e519524SHoward Hinnant    return true;
13913e519524SHoward Hinnant}
13923e519524SHoward Hinnant
13933e519524SHoward Hinnanttemplate<class _ForwardIterator1, class _ForwardIterator2>
13941362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
13951362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
13963e519524SHoward Hinnantbool
13973e519524SHoward Hinnantis_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
13983e519524SHoward Hinnant               _ForwardIterator2 __first2)
13993e519524SHoward Hinnant{
14003e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator1>::value_type __v1;
14013e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator2>::value_type __v2;
1402ce48a113SHoward Hinnant    return _VSTD::is_permutation(__first1, __last1, __first2, __equal_to<__v1, __v2>());
14033e519524SHoward Hinnant}
14043e519524SHoward Hinnant
14050b0bbd2fSMarshall Clow#if _LIBCPP_STD_VER > 11
14060b0bbd2fSMarshall Clowtemplate<class _BinaryPredicate, class _ForwardIterator1, class _ForwardIterator2>
140749c7643cSMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
14080b0bbd2fSMarshall Clow__is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
14090b0bbd2fSMarshall Clow                 _ForwardIterator2 __first2, _ForwardIterator2 __last2,
14100b0bbd2fSMarshall Clow                 _BinaryPredicate __pred,
14110b0bbd2fSMarshall Clow                 forward_iterator_tag, forward_iterator_tag )
14120b0bbd2fSMarshall Clow{
141349c7643cSMarshall Clow//  shorten sequences as much as possible by lopping of any equal prefix
1414847ee131SEric Fiselier    for (; __first1 != __last1 && __first2 != __last2; ++__first1, (void) ++__first2)
14150b0bbd2fSMarshall Clow        if (!__pred(*__first1, *__first2))
141649c7643cSMarshall Clow            break;
141749c7643cSMarshall Clow    if (__first1 == __last1)
141849c7643cSMarshall Clow        return __first2 == __last2;
141949c7643cSMarshall Clow    else if (__first2 == __last2)
142049c7643cSMarshall Clow        return false;
142149c7643cSMarshall Clow
14220b0bbd2fSMarshall Clow    typedef typename iterator_traits<_ForwardIterator1>::difference_type _D1;
14230b0bbd2fSMarshall Clow    _D1 __l1 = _VSTD::distance(__first1, __last1);
14240b0bbd2fSMarshall Clow
14250b0bbd2fSMarshall Clow    typedef typename iterator_traits<_ForwardIterator2>::difference_type _D2;
1426fce85ba4SMarshall Clow    _D2 __l2 = _VSTD::distance(__first2, __last2);
14270b0bbd2fSMarshall Clow    if (__l1 != __l2)
14280b0bbd2fSMarshall Clow        return false;
14290b0bbd2fSMarshall Clow
14300b0bbd2fSMarshall Clow    // For each element in [f1, l1) see if there are the same number of
14310b0bbd2fSMarshall Clow    //    equal elements in [f2, l2)
14320b0bbd2fSMarshall Clow    for (_ForwardIterator1 __i = __first1; __i != __last1; ++__i)
14330b0bbd2fSMarshall Clow    {
14340b0bbd2fSMarshall Clow    //  Have we already counted the number of *__i in [f1, l1)?
1435939b1623SPeter Collingbourne        _ForwardIterator1 __match = __first1;
1436939b1623SPeter Collingbourne        for (; __match != __i; ++__match)
1437939b1623SPeter Collingbourne            if (__pred(*__match, *__i))
1438939b1623SPeter Collingbourne                break;
1439939b1623SPeter Collingbourne        if (__match == __i) {
14400b0bbd2fSMarshall Clow            // Count number of *__i in [f2, l2)
14410b0bbd2fSMarshall Clow            _D1 __c2 = 0;
14420b0bbd2fSMarshall Clow            for (_ForwardIterator2 __j = __first2; __j != __last2; ++__j)
14430b0bbd2fSMarshall Clow                if (__pred(*__i, *__j))
14440b0bbd2fSMarshall Clow                    ++__c2;
14450b0bbd2fSMarshall Clow            if (__c2 == 0)
14460b0bbd2fSMarshall Clow                return false;
14470b0bbd2fSMarshall Clow            // Count number of *__i in [__i, l1) (we can start with 1)
14480b0bbd2fSMarshall Clow            _D1 __c1 = 1;
14490b0bbd2fSMarshall Clow            for (_ForwardIterator1 __j = _VSTD::next(__i); __j != __last1; ++__j)
14500b0bbd2fSMarshall Clow                if (__pred(*__i, *__j))
14510b0bbd2fSMarshall Clow                    ++__c1;
14520b0bbd2fSMarshall Clow            if (__c1 != __c2)
14530b0bbd2fSMarshall Clow                return false;
14540b0bbd2fSMarshall Clow        }
14550b0bbd2fSMarshall Clow    }
14560b0bbd2fSMarshall Clow    return true;
14570b0bbd2fSMarshall Clow}
14580b0bbd2fSMarshall Clow
14590b0bbd2fSMarshall Clowtemplate<class _BinaryPredicate, class _RandomAccessIterator1, class _RandomAccessIterator2>
146049c7643cSMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
14610b0bbd2fSMarshall Clow__is_permutation(_RandomAccessIterator1 __first1, _RandomAccessIterator2 __last1,
14620b0bbd2fSMarshall Clow               _RandomAccessIterator1 __first2, _RandomAccessIterator2 __last2,
14630b0bbd2fSMarshall Clow               _BinaryPredicate __pred,
14640b0bbd2fSMarshall Clow               random_access_iterator_tag, random_access_iterator_tag )
14650b0bbd2fSMarshall Clow{
14660b0bbd2fSMarshall Clow    if ( _VSTD::distance(__first1, __last1) != _VSTD::distance(__first2, __last2))
14670b0bbd2fSMarshall Clow        return false;
14680b0bbd2fSMarshall Clow    return _VSTD::is_permutation<_RandomAccessIterator1, _RandomAccessIterator2,
14690b0bbd2fSMarshall Clow                                 typename add_lvalue_reference<_BinaryPredicate>::type>
14700b0bbd2fSMarshall Clow                                (__first1, __last1, __first2, __pred );
14710b0bbd2fSMarshall Clow}
14720b0bbd2fSMarshall Clow
14730b0bbd2fSMarshall Clowtemplate<class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
14741362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
14751362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
14760b0bbd2fSMarshall Clowbool
14770b0bbd2fSMarshall Clowis_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
14780b0bbd2fSMarshall Clow               _ForwardIterator2 __first2, _ForwardIterator2 __last2,
14790b0bbd2fSMarshall Clow               _BinaryPredicate __pred )
14800b0bbd2fSMarshall Clow{
14810b0bbd2fSMarshall Clow    return _VSTD::__is_permutation<typename add_lvalue_reference<_BinaryPredicate>::type>
14820b0bbd2fSMarshall Clow       (__first1, __last1, __first2, __last2, __pred,
14830b0bbd2fSMarshall Clow        typename iterator_traits<_ForwardIterator1>::iterator_category(),
14840b0bbd2fSMarshall Clow        typename iterator_traits<_ForwardIterator2>::iterator_category());
14850b0bbd2fSMarshall Clow}
14860b0bbd2fSMarshall Clow
14870b0bbd2fSMarshall Clowtemplate<class _ForwardIterator1, class _ForwardIterator2>
14881362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
14891362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
14900b0bbd2fSMarshall Clowbool
14910b0bbd2fSMarshall Clowis_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
14920b0bbd2fSMarshall Clow               _ForwardIterator2 __first2, _ForwardIterator2 __last2)
14930b0bbd2fSMarshall Clow{
14940b0bbd2fSMarshall Clow    typedef typename iterator_traits<_ForwardIterator1>::value_type __v1;
14950b0bbd2fSMarshall Clow    typedef typename iterator_traits<_ForwardIterator2>::value_type __v2;
14960b0bbd2fSMarshall Clow    return _VSTD::__is_permutation(__first1, __last1, __first2, __last2,
14970b0bbd2fSMarshall Clow        __equal_to<__v1, __v2>(),
14980b0bbd2fSMarshall Clow        typename iterator_traits<_ForwardIterator1>::iterator_category(),
14990b0bbd2fSMarshall Clow        typename iterator_traits<_ForwardIterator2>::iterator_category());
15000b0bbd2fSMarshall Clow}
15010b0bbd2fSMarshall Clow#endif
15020b0bbd2fSMarshall Clow
15033e519524SHoward Hinnant// search
1504d835e592SMarshall Clow// __search is in <functional>
15053e519524SHoward Hinnant
15063e519524SHoward Hinnanttemplate <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
15071362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
15081362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
15093e519524SHoward Hinnant_ForwardIterator1
15103e519524SHoward Hinnantsearch(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
15113e519524SHoward Hinnant       _ForwardIterator2 __first2, _ForwardIterator2 __last2, _BinaryPredicate __pred)
15123e519524SHoward Hinnant{
1513ce48a113SHoward Hinnant    return _VSTD::__search<typename add_lvalue_reference<_BinaryPredicate>::type>
15143e519524SHoward Hinnant                         (__first1, __last1, __first2, __last2, __pred,
151528cc4ddeSMarshall Clow                          typename iterator_traits<_ForwardIterator1>::iterator_category(),
151628cc4ddeSMarshall Clow                          typename iterator_traits<_ForwardIterator2>::iterator_category())
151728cc4ddeSMarshall Clow            .first;
15183e519524SHoward Hinnant}
15193e519524SHoward Hinnant
15203e519524SHoward Hinnanttemplate <class _ForwardIterator1, class _ForwardIterator2>
15211362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
15221362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
15233e519524SHoward Hinnant_ForwardIterator1
15243e519524SHoward Hinnantsearch(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
15253e519524SHoward Hinnant       _ForwardIterator2 __first2, _ForwardIterator2 __last2)
15263e519524SHoward Hinnant{
152728cc4ddeSMarshall Clow    typedef typename iterator_traits<_ForwardIterator1>::value_type __v1;
152828cc4ddeSMarshall Clow    typedef typename iterator_traits<_ForwardIterator2>::value_type __v2;
1529ce48a113SHoward Hinnant    return _VSTD::search(__first1, __last1, __first2, __last2, __equal_to<__v1, __v2>());
15303e519524SHoward Hinnant}
15313e519524SHoward Hinnant
1532d835e592SMarshall Clow
1533d835e592SMarshall Clow#if _LIBCPP_STD_VER > 14
1534d835e592SMarshall Clowtemplate <class _ForwardIterator, class _Searcher>
15351362d7efSNico Weber_LIBCPP_NODISCARD_EXT _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
1536d835e592SMarshall Clow_ForwardIterator search(_ForwardIterator __f, _ForwardIterator __l, const _Searcher &__s)
1537d835e592SMarshall Clow{ return __s(__f, __l).first; }
1538d835e592SMarshall Clow#endif
1539d835e592SMarshall Clow
15403e519524SHoward Hinnant// search_n
15413e519524SHoward Hinnant
15423e519524SHoward Hinnanttemplate <class _BinaryPredicate, class _ForwardIterator, class _Size, class _Tp>
154312f0a779SMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
15443e519524SHoward Hinnant__search_n(_ForwardIterator __first, _ForwardIterator __last,
1545e4383379SHoward Hinnant           _Size __count, const _Tp& __value_, _BinaryPredicate __pred, forward_iterator_tag)
15463e519524SHoward Hinnant{
15473e519524SHoward Hinnant    if (__count <= 0)
15483e519524SHoward Hinnant        return __first;
15493e519524SHoward Hinnant    while (true)
15503e519524SHoward Hinnant    {
1551e4383379SHoward Hinnant        // Find first element in sequence that matchs __value_, with a mininum of loop checks
15523e519524SHoward Hinnant        while (true)
15533e519524SHoward Hinnant        {
1554e4383379SHoward Hinnant            if (__first == __last)  // return __last if no element matches __value_
15553e519524SHoward Hinnant                return __last;
1556e4383379SHoward Hinnant            if (__pred(*__first, __value_))
15573e519524SHoward Hinnant                break;
15583e519524SHoward Hinnant            ++__first;
15593e519524SHoward Hinnant        }
1560e4383379SHoward Hinnant        // *__first matches __value_, now match elements after here
15613e519524SHoward Hinnant        _ForwardIterator __m = __first;
15623e519524SHoward Hinnant        _Size __c(0);
15633e519524SHoward Hinnant        while (true)
15643e519524SHoward Hinnant        {
15653e519524SHoward Hinnant            if (++__c == __count)  // If pattern exhausted, __first is the answer (works for 1 element pattern)
15663e519524SHoward Hinnant                return __first;
15673e519524SHoward Hinnant            if (++__m == __last)  // Otherwise if source exhaused, pattern not found
15683e519524SHoward Hinnant                return __last;
1569e4383379SHoward Hinnant            if (!__pred(*__m, __value_))  // if there is a mismatch, restart with a new __first
15703e519524SHoward Hinnant            {
15713e519524SHoward Hinnant                __first = __m;
15723e519524SHoward Hinnant                ++__first;
15733e519524SHoward Hinnant                break;
15743e519524SHoward Hinnant            }  // else there is a match, check next elements
15753e519524SHoward Hinnant        }
15763e519524SHoward Hinnant    }
15773e519524SHoward Hinnant}
15783e519524SHoward Hinnant
15793e519524SHoward Hinnanttemplate <class _BinaryPredicate, class _RandomAccessIterator, class _Size, class _Tp>
158012f0a779SMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 _RandomAccessIterator
15813e519524SHoward Hinnant__search_n(_RandomAccessIterator __first, _RandomAccessIterator __last,
1582e4383379SHoward Hinnant           _Size __count, const _Tp& __value_, _BinaryPredicate __pred, random_access_iterator_tag)
15833e519524SHoward Hinnant{
15843e519524SHoward Hinnant    if (__count <= 0)
15853e519524SHoward Hinnant        return __first;
15863e519524SHoward Hinnant    _Size __len = static_cast<_Size>(__last - __first);
15873e519524SHoward Hinnant    if (__len < __count)
15883e519524SHoward Hinnant        return __last;
15893e519524SHoward Hinnant    const _RandomAccessIterator __s = __last - (__count - 1);  // Start of pattern match can't go beyond here
15903e519524SHoward Hinnant    while (true)
15913e519524SHoward Hinnant    {
1592e4383379SHoward Hinnant        // Find first element in sequence that matchs __value_, with a mininum of loop checks
15933e519524SHoward Hinnant        while (true)
15943e519524SHoward Hinnant        {
1595b13fcad6SHoward Hinnant            if (__first >= __s)  // return __last if no element matches __value_
15963e519524SHoward Hinnant                return __last;
1597e4383379SHoward Hinnant            if (__pred(*__first, __value_))
15983e519524SHoward Hinnant                break;
15993e519524SHoward Hinnant            ++__first;
16003e519524SHoward Hinnant        }
1601e4383379SHoward Hinnant        // *__first matches __value_, now match elements after here
16023e519524SHoward Hinnant        _RandomAccessIterator __m = __first;
16033e519524SHoward Hinnant        _Size __c(0);
16043e519524SHoward Hinnant        while (true)
16053e519524SHoward Hinnant        {
16063e519524SHoward Hinnant            if (++__c == __count)  // If pattern exhausted, __first is the answer (works for 1 element pattern)
16073e519524SHoward Hinnant                return __first;
16083e519524SHoward Hinnant             ++__m;          // no need to check range on __m because __s guarantees we have enough source
1609e4383379SHoward Hinnant            if (!__pred(*__m, __value_))  // if there is a mismatch, restart with a new __first
16103e519524SHoward Hinnant            {
16113e519524SHoward Hinnant                __first = __m;
16123e519524SHoward Hinnant                ++__first;
16133e519524SHoward Hinnant                break;
16143e519524SHoward Hinnant            }  // else there is a match, check next elements
16153e519524SHoward Hinnant        }
16163e519524SHoward Hinnant    }
16173e519524SHoward Hinnant}
16183e519524SHoward Hinnant
16193e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Size, class _Tp, class _BinaryPredicate>
16201362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
16211362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
16223e519524SHoward Hinnant_ForwardIterator
16233e519524SHoward Hinnantsearch_n(_ForwardIterator __first, _ForwardIterator __last,
1624e4383379SHoward Hinnant         _Size __count, const _Tp& __value_, _BinaryPredicate __pred)
16253e519524SHoward Hinnant{
1626ce48a113SHoward Hinnant    return _VSTD::__search_n<typename add_lvalue_reference<_BinaryPredicate>::type>
1627c0428b3cSArthur O'Dwyer           (__first, __last, _VSTD::__convert_to_integral(__count), __value_, __pred,
162851544023SEric Fiselier           typename iterator_traits<_ForwardIterator>::iterator_category());
16293e519524SHoward Hinnant}
16303e519524SHoward Hinnant
16313e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Size, class _Tp>
16321362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
16331362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
16343e519524SHoward Hinnant_ForwardIterator
1635e4383379SHoward Hinnantsearch_n(_ForwardIterator __first, _ForwardIterator __last, _Size __count, const _Tp& __value_)
16363e519524SHoward Hinnant{
16373e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator>::value_type __v;
1638c0428b3cSArthur O'Dwyer    return _VSTD::search_n(__first, __last, _VSTD::__convert_to_integral(__count),
163951544023SEric Fiselier                           __value_, __equal_to<__v, _Tp>());
16403e519524SHoward Hinnant}
16413e519524SHoward Hinnant
1642d41c6d51SArthur O'Dwyer// __unwrap_iter
1643d41c6d51SArthur O'Dwyer
1644d41c6d51SArthur O'Dwyer// The job of __unwrap_iter is to lower iterators-that-are-tantamount-to-pointers
1645d41c6d51SArthur O'Dwyer// (such as vector<T>::iterator) into pointers, to reduce the number of template
1646d41c6d51SArthur O'Dwyer// instantiations and to enable pointer-based optimizations e.g. in std::copy.
1647d41c6d51SArthur O'Dwyer// In debug mode, we don't do this.
1648d41c6d51SArthur O'Dwyer
1649d41c6d51SArthur O'Dwyertemplate <class _Iter, bool = __is_cpp17_contiguous_iterator<_Iter>::value>
1650d41c6d51SArthur O'Dwyerstruct __unwrap_iter_impl {
1651d41c6d51SArthur O'Dwyer    static _LIBCPP_CONSTEXPR _Iter
1652d41c6d51SArthur O'Dwyer    __apply(_Iter __i) _NOEXCEPT {
16533e519524SHoward Hinnant        return __i;
16543e519524SHoward Hinnant    }
1655d41c6d51SArthur O'Dwyer};
16563e519524SHoward Hinnant
1657fc88dbd2SHoward Hinnant#if _LIBCPP_DEBUG_LEVEL < 2
1658fc88dbd2SHoward Hinnant
1659d41c6d51SArthur O'Dwyertemplate <class _Iter>
1660d41c6d51SArthur O'Dwyerstruct __unwrap_iter_impl<_Iter, true> {
1661d41c6d51SArthur O'Dwyer    static _LIBCPP_CONSTEXPR decltype(_VSTD::__to_address(declval<_Iter>()))
1662d41c6d51SArthur O'Dwyer    __apply(_Iter __i) _NOEXCEPT {
1663d41c6d51SArthur O'Dwyer        return _VSTD::__to_address(__i);
16643e519524SHoward Hinnant    }
1665d41c6d51SArthur O'Dwyer};
166614bd0bf0SEric Fiselier
1667fc88dbd2SHoward Hinnant#endif  // _LIBCPP_DEBUG_LEVEL < 2
1668fc88dbd2SHoward Hinnant
1669d41c6d51SArthur O'Dwyertemplate<class _Iter, class _Impl = __unwrap_iter_impl<_Iter> >
1670d41c6d51SArthur O'Dwyerinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
1671d41c6d51SArthur O'Dwyerdecltype(_Impl::__apply(_VSTD::declval<_Iter>()))
1672d41c6d51SArthur O'Dwyer__unwrap_iter(_Iter __i) _NOEXCEPT
1673d41c6d51SArthur O'Dwyer{
1674d41c6d51SArthur O'Dwyer    return _Impl::__apply(__i);
1675d41c6d51SArthur O'Dwyer}
1676d41c6d51SArthur O'Dwyer
1677d41c6d51SArthur O'Dwyer// copy
1678d41c6d51SArthur O'Dwyer
16793e519524SHoward Hinnanttemplate <class _InputIterator, class _OutputIterator>
168013c90a57SLouis Dionneinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
16813e519524SHoward Hinnant_OutputIterator
168213c90a57SLouis Dionne__copy_constexpr(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
16833e519524SHoward Hinnant{
1684910285b2SEric Fiselier    for (; __first != __last; ++__first, (void) ++__result)
16853e519524SHoward Hinnant        *__result = *__first;
16863e519524SHoward Hinnant    return __result;
16873e519524SHoward Hinnant}
16883e519524SHoward Hinnant
168913c90a57SLouis Dionnetemplate <class _InputIterator, class _OutputIterator>
169013c90a57SLouis Dionneinline _LIBCPP_INLINE_VISIBILITY
169113c90a57SLouis Dionne_OutputIterator
169213c90a57SLouis Dionne__copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
169313c90a57SLouis Dionne{
16941968804aSArthur O'Dwyer    return _VSTD::__copy_constexpr(__first, __last, __result);
169513c90a57SLouis Dionne}
169613c90a57SLouis Dionne
16973e519524SHoward Hinnanttemplate <class _Tp, class _Up>
16983e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
16993e519524SHoward Hinnanttypename enable_if
17003e519524SHoward Hinnant<
17013e519524SHoward Hinnant    is_same<typename remove_const<_Tp>::type, _Up>::value &&
1702ca740483SHoward Hinnant    is_trivially_copy_assignable<_Up>::value,
17033e519524SHoward Hinnant    _Up*
17043e519524SHoward Hinnant>::type
17053e519524SHoward Hinnant__copy(_Tp* __first, _Tp* __last, _Up* __result)
17063e519524SHoward Hinnant{
17073e519524SHoward Hinnant    const size_t __n = static_cast<size_t>(__last - __first);
17085b312052SMarshall Clow    if (__n > 0)
1709ce48a113SHoward Hinnant        _VSTD::memmove(__result, __first, __n * sizeof(_Up));
17103e519524SHoward Hinnant    return __result + __n;
17113e519524SHoward Hinnant}
17123e519524SHoward Hinnant
17133e519524SHoward Hinnanttemplate <class _InputIterator, class _OutputIterator>
1714ee95c702SArthur O'Dwyerinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
17153e519524SHoward Hinnant_OutputIterator
17163e519524SHoward Hinnantcopy(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
17173e519524SHoward Hinnant{
171813c90a57SLouis Dionne    if (__libcpp_is_constant_evaluated()) {
171913c90a57SLouis Dionne        return _VSTD::__copy_constexpr(
17201968804aSArthur O'Dwyer            _VSTD::__unwrap_iter(__first), _VSTD::__unwrap_iter(__last), _VSTD::__unwrap_iter(__result));
172113c90a57SLouis Dionne    } else {
172213c90a57SLouis Dionne        return _VSTD::__copy(
17231968804aSArthur O'Dwyer            _VSTD::__unwrap_iter(__first), _VSTD::__unwrap_iter(__last), _VSTD::__unwrap_iter(__result));
172413c90a57SLouis Dionne    }
17253e519524SHoward Hinnant}
17263e519524SHoward Hinnant
17273e519524SHoward Hinnant// copy_backward
17283e519524SHoward Hinnant
1729d3d4356fSHoward Hinnanttemplate <class _BidirectionalIterator, class _OutputIterator>
173013c90a57SLouis Dionneinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
173113c90a57SLouis Dionne_OutputIterator
173213c90a57SLouis Dionne__copy_backward_constexpr(_BidirectionalIterator __first, _BidirectionalIterator __last, _OutputIterator __result)
173313c90a57SLouis Dionne{
173413c90a57SLouis Dionne    while (__first != __last)
173513c90a57SLouis Dionne        *--__result = *--__last;
173613c90a57SLouis Dionne    return __result;
173713c90a57SLouis Dionne}
173813c90a57SLouis Dionne
173913c90a57SLouis Dionnetemplate <class _BidirectionalIterator, class _OutputIterator>
17403e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
17413e519524SHoward Hinnant_OutputIterator
1742d3d4356fSHoward Hinnant__copy_backward(_BidirectionalIterator __first, _BidirectionalIterator __last, _OutputIterator __result)
17433e519524SHoward Hinnant{
17441968804aSArthur O'Dwyer    return _VSTD::__copy_backward_constexpr(__first, __last, __result);
17453e519524SHoward Hinnant}
17463e519524SHoward Hinnant
17473e519524SHoward Hinnanttemplate <class _Tp, class _Up>
17483e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
17493e519524SHoward Hinnanttypename enable_if
17503e519524SHoward Hinnant<
17513e519524SHoward Hinnant    is_same<typename remove_const<_Tp>::type, _Up>::value &&
1752ca740483SHoward Hinnant    is_trivially_copy_assignable<_Up>::value,
17533e519524SHoward Hinnant    _Up*
17543e519524SHoward Hinnant>::type
17553e519524SHoward Hinnant__copy_backward(_Tp* __first, _Tp* __last, _Up* __result)
17563e519524SHoward Hinnant{
17573e519524SHoward Hinnant    const size_t __n = static_cast<size_t>(__last - __first);
17585b312052SMarshall Clow    if (__n > 0)
17595b312052SMarshall Clow    {
17603e519524SHoward Hinnant        __result -= __n;
1761ce48a113SHoward Hinnant        _VSTD::memmove(__result, __first, __n * sizeof(_Up));
17625b312052SMarshall Clow    }
17633e519524SHoward Hinnant    return __result;
17643e519524SHoward Hinnant}
17653e519524SHoward Hinnant
17663e519524SHoward Hinnanttemplate <class _BidirectionalIterator1, class _BidirectionalIterator2>
1767ee95c702SArthur O'Dwyerinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
17683e519524SHoward Hinnant_BidirectionalIterator2
17693e519524SHoward Hinnantcopy_backward(_BidirectionalIterator1 __first, _BidirectionalIterator1 __last,
17703e519524SHoward Hinnant              _BidirectionalIterator2 __result)
17713e519524SHoward Hinnant{
177213c90a57SLouis Dionne    if (__libcpp_is_constant_evaluated()) {
17731968804aSArthur O'Dwyer        return _VSTD::__copy_backward_constexpr(_VSTD::__unwrap_iter(__first),
17741968804aSArthur O'Dwyer                                                _VSTD::__unwrap_iter(__last),
17751968804aSArthur O'Dwyer                                                _VSTD::__unwrap_iter(__result));
177613c90a57SLouis Dionne    } else {
17771968804aSArthur O'Dwyer        return _VSTD::__copy_backward(_VSTD::__unwrap_iter(__first),
17781968804aSArthur O'Dwyer                                      _VSTD::__unwrap_iter(__last),
17791968804aSArthur O'Dwyer                                      _VSTD::__unwrap_iter(__result));
17803e519524SHoward Hinnant    }
178113c90a57SLouis Dionne}
17823e519524SHoward Hinnant
17833e519524SHoward Hinnant// copy_if
17843e519524SHoward Hinnant
17853e519524SHoward Hinnanttemplate<class _InputIterator, class _OutputIterator, class _Predicate>
178613c90a57SLouis Dionneinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
17873e519524SHoward Hinnant_OutputIterator
17883e519524SHoward Hinnantcopy_if(_InputIterator __first, _InputIterator __last,
17893e519524SHoward Hinnant        _OutputIterator __result, _Predicate __pred)
17903e519524SHoward Hinnant{
17913e519524SHoward Hinnant    for (; __first != __last; ++__first)
17923e519524SHoward Hinnant    {
17933e519524SHoward Hinnant        if (__pred(*__first))
17943e519524SHoward Hinnant        {
17953e519524SHoward Hinnant            *__result = *__first;
17963e519524SHoward Hinnant            ++__result;
17973e519524SHoward Hinnant        }
17983e519524SHoward Hinnant    }
17993e519524SHoward Hinnant    return __result;
18003e519524SHoward Hinnant}
18013e519524SHoward Hinnant
18023e519524SHoward Hinnant// copy_n
18033e519524SHoward Hinnant
18043e519524SHoward Hinnanttemplate<class _InputIterator, class _Size, class _OutputIterator>
1805ee95c702SArthur O'Dwyerinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
18063e519524SHoward Hinnanttypename enable_if
18073e519524SHoward Hinnant<
1808f82dba01SEric Fiselier    __is_cpp17_input_iterator<_InputIterator>::value &&
1809f82dba01SEric Fiselier   !__is_cpp17_random_access_iterator<_InputIterator>::value,
18103e519524SHoward Hinnant    _OutputIterator
18113e519524SHoward Hinnant>::type
181251544023SEric Fiseliercopy_n(_InputIterator __first, _Size __orig_n, _OutputIterator __result)
18133e519524SHoward Hinnant{
1814c0428b3cSArthur O'Dwyer    typedef decltype(_VSTD::__convert_to_integral(__orig_n)) _IntegralSize;
181551544023SEric Fiselier    _IntegralSize __n = __orig_n;
181699847d2bSHoward Hinnant    if (__n > 0)
181799847d2bSHoward Hinnant    {
18183e519524SHoward Hinnant        *__result = *__first;
181999847d2bSHoward Hinnant        ++__result;
182099847d2bSHoward Hinnant        for (--__n; __n > 0; --__n)
182199847d2bSHoward Hinnant        {
182299847d2bSHoward Hinnant            ++__first;
182399847d2bSHoward Hinnant            *__result = *__first;
182499847d2bSHoward Hinnant            ++__result;
182599847d2bSHoward Hinnant        }
182699847d2bSHoward Hinnant    }
18273e519524SHoward Hinnant    return __result;
18283e519524SHoward Hinnant}
18293e519524SHoward Hinnant
18303e519524SHoward Hinnanttemplate<class _InputIterator, class _Size, class _OutputIterator>
1831ee95c702SArthur O'Dwyerinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
18323e519524SHoward Hinnanttypename enable_if
18333e519524SHoward Hinnant<
1834f82dba01SEric Fiselier    __is_cpp17_random_access_iterator<_InputIterator>::value,
18353e519524SHoward Hinnant    _OutputIterator
18363e519524SHoward Hinnant>::type
183751544023SEric Fiseliercopy_n(_InputIterator __first, _Size __orig_n, _OutputIterator __result)
18383e519524SHoward Hinnant{
1839c0428b3cSArthur O'Dwyer    typedef decltype(_VSTD::__convert_to_integral(__orig_n)) _IntegralSize;
184051544023SEric Fiselier    _IntegralSize __n = __orig_n;
1841ce48a113SHoward Hinnant    return _VSTD::copy(__first, __first + __n, __result);
18423e519524SHoward Hinnant}
18433e519524SHoward Hinnant
18443e519524SHoward Hinnant// move
18453e519524SHoward Hinnant
18463ed89b51Szoecarver// __move_constexpr exists so that __move doesn't call itself when delegating to the constexpr
18473ed89b51Szoecarver// version of __move.
18483e519524SHoward Hinnanttemplate <class _InputIterator, class _OutputIterator>
18493ed89b51Szoecarverinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
18503e519524SHoward Hinnant_OutputIterator
18513ed89b51Szoecarver__move_constexpr(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
18523e519524SHoward Hinnant{
1853910285b2SEric Fiselier    for (; __first != __last; ++__first, (void) ++__result)
1854ce48a113SHoward Hinnant        *__result = _VSTD::move(*__first);
18553e519524SHoward Hinnant    return __result;
18563e519524SHoward Hinnant}
18573e519524SHoward Hinnant
18583ed89b51Szoecarvertemplate <class _InputIterator, class _OutputIterator>
18593ed89b51Szoecarverinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
18603ed89b51Szoecarver_OutputIterator
18613ed89b51Szoecarver__move(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
18623ed89b51Szoecarver{
18631968804aSArthur O'Dwyer    return _VSTD::__move_constexpr(__first, __last, __result);
18643ed89b51Szoecarver}
18653ed89b51Szoecarver
18663e519524SHoward Hinnanttemplate <class _Tp, class _Up>
18673ed89b51Szoecarverinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
18683e519524SHoward Hinnanttypename enable_if
18693e519524SHoward Hinnant<
18703e519524SHoward Hinnant    is_same<typename remove_const<_Tp>::type, _Up>::value &&
1871d41c6d51SArthur O'Dwyer    is_trivially_move_assignable<_Up>::value,
18723e519524SHoward Hinnant    _Up*
18733e519524SHoward Hinnant>::type
18743e519524SHoward Hinnant__move(_Tp* __first, _Tp* __last, _Up* __result)
18753e519524SHoward Hinnant{
18763ed89b51Szoecarver    if (__libcpp_is_constant_evaluated())
18771968804aSArthur O'Dwyer        return _VSTD::__move_constexpr(__first, __last, __result);
18783e519524SHoward Hinnant    const size_t __n = static_cast<size_t>(__last - __first);
18795b312052SMarshall Clow    if (__n > 0)
1880ce48a113SHoward Hinnant        _VSTD::memmove(__result, __first, __n * sizeof(_Up));
18813e519524SHoward Hinnant    return __result + __n;
18823e519524SHoward Hinnant}
18833e519524SHoward Hinnant
18843e519524SHoward Hinnanttemplate <class _InputIterator, class _OutputIterator>
18853ed89b51Szoecarverinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
18863e519524SHoward Hinnant_OutputIterator
18873e519524SHoward Hinnantmove(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
18883e519524SHoward Hinnant{
18891968804aSArthur O'Dwyer    return _VSTD::__move(_VSTD::__unwrap_iter(__first), _VSTD::__unwrap_iter(__last), _VSTD::__unwrap_iter(__result));
18903e519524SHoward Hinnant}
18913e519524SHoward Hinnant
18923e519524SHoward Hinnant// move_backward
18933e519524SHoward Hinnant
18943ed89b51Szoecarver// __move_backward_constexpr exists so that __move_backward doesn't call itself when delegating to
18953ed89b51Szoecarver// the constexpr version of __move_backward.
18963e519524SHoward Hinnanttemplate <class _InputIterator, class _OutputIterator>
18973ed89b51Szoecarverinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
18983e519524SHoward Hinnant_OutputIterator
18993ed89b51Szoecarver__move_backward_constexpr(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
19003e519524SHoward Hinnant{
19013e519524SHoward Hinnant    while (__first != __last)
1902ce48a113SHoward Hinnant        *--__result = _VSTD::move(*--__last);
19033e519524SHoward Hinnant    return __result;
19043e519524SHoward Hinnant}
19053e519524SHoward Hinnant
19063ed89b51Szoecarvertemplate <class _InputIterator, class _OutputIterator>
19073ed89b51Szoecarverinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
19083ed89b51Szoecarver_OutputIterator
19093ed89b51Szoecarver__move_backward(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
19103ed89b51Szoecarver{
19111968804aSArthur O'Dwyer    return _VSTD::__move_backward_constexpr(__first, __last, __result);
19123ed89b51Szoecarver}
19133ed89b51Szoecarver
19143e519524SHoward Hinnanttemplate <class _Tp, class _Up>
19153ed89b51Szoecarverinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
19163e519524SHoward Hinnanttypename enable_if
19173e519524SHoward Hinnant<
19183e519524SHoward Hinnant    is_same<typename remove_const<_Tp>::type, _Up>::value &&
1919d41c6d51SArthur O'Dwyer    is_trivially_move_assignable<_Up>::value,
19203e519524SHoward Hinnant    _Up*
19213e519524SHoward Hinnant>::type
19223e519524SHoward Hinnant__move_backward(_Tp* __first, _Tp* __last, _Up* __result)
19233e519524SHoward Hinnant{
19243ed89b51Szoecarver    if (__libcpp_is_constant_evaluated())
19251968804aSArthur O'Dwyer        return _VSTD::__move_backward_constexpr(__first, __last, __result);
19263e519524SHoward Hinnant    const size_t __n = static_cast<size_t>(__last - __first);
19275b312052SMarshall Clow    if (__n > 0)
19285b312052SMarshall Clow    {
19293e519524SHoward Hinnant        __result -= __n;
1930ce48a113SHoward Hinnant        _VSTD::memmove(__result, __first, __n * sizeof(_Up));
19315b312052SMarshall Clow    }
19323e519524SHoward Hinnant    return __result;
19333e519524SHoward Hinnant}
19343e519524SHoward Hinnant
19353e519524SHoward Hinnanttemplate <class _BidirectionalIterator1, class _BidirectionalIterator2>
19363ed89b51Szoecarverinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
19373e519524SHoward Hinnant_BidirectionalIterator2
19383e519524SHoward Hinnantmove_backward(_BidirectionalIterator1 __first, _BidirectionalIterator1 __last,
19393e519524SHoward Hinnant              _BidirectionalIterator2 __result)
19403e519524SHoward Hinnant{
19411968804aSArthur O'Dwyer    return _VSTD::__move_backward(_VSTD::__unwrap_iter(__first), _VSTD::__unwrap_iter(__last), _VSTD::__unwrap_iter(__result));
19423e519524SHoward Hinnant}
19433e519524SHoward Hinnant
19443e519524SHoward Hinnant// iter_swap
19453e519524SHoward Hinnant
1946a676f7d3SHoward Hinnant// moved to <type_traits> for better swap / noexcept support
19473e519524SHoward Hinnant
19483e519524SHoward Hinnant// transform
19493e519524SHoward Hinnant
19503e519524SHoward Hinnanttemplate <class _InputIterator, class _OutputIterator, class _UnaryOperation>
195199894b61SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
19523e519524SHoward Hinnant_OutputIterator
19533e519524SHoward Hinnanttransform(_InputIterator __first, _InputIterator __last, _OutputIterator __result, _UnaryOperation __op)
19543e519524SHoward Hinnant{
1955910285b2SEric Fiselier    for (; __first != __last; ++__first, (void) ++__result)
19563e519524SHoward Hinnant        *__result = __op(*__first);
19573e519524SHoward Hinnant    return __result;
19583e519524SHoward Hinnant}
19593e519524SHoward Hinnant
19603e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _BinaryOperation>
196199894b61SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
19623e519524SHoward Hinnant_OutputIterator
19633e519524SHoward Hinnanttransform(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2,
19643e519524SHoward Hinnant          _OutputIterator __result, _BinaryOperation __binary_op)
19653e519524SHoward Hinnant{
1966910285b2SEric Fiselier    for (; __first1 != __last1; ++__first1, (void) ++__first2, ++__result)
19673e519524SHoward Hinnant        *__result = __binary_op(*__first1, *__first2);
19683e519524SHoward Hinnant    return __result;
19693e519524SHoward Hinnant}
19703e519524SHoward Hinnant
19713e519524SHoward Hinnant// replace
19723e519524SHoward Hinnant
19733e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Tp>
197412c7423fSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
19753e519524SHoward Hinnantvoid
19763e519524SHoward Hinnantreplace(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __old_value, const _Tp& __new_value)
19773e519524SHoward Hinnant{
19783e519524SHoward Hinnant    for (; __first != __last; ++__first)
19793e519524SHoward Hinnant        if (*__first == __old_value)
19803e519524SHoward Hinnant            *__first = __new_value;
19813e519524SHoward Hinnant}
19823e519524SHoward Hinnant
19833e519524SHoward Hinnant// replace_if
19843e519524SHoward Hinnant
19853e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Predicate, class _Tp>
198612c7423fSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
19873e519524SHoward Hinnantvoid
19883e519524SHoward Hinnantreplace_if(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred, const _Tp& __new_value)
19893e519524SHoward Hinnant{
19903e519524SHoward Hinnant    for (; __first != __last; ++__first)
19913e519524SHoward Hinnant        if (__pred(*__first))
19923e519524SHoward Hinnant            *__first = __new_value;
19933e519524SHoward Hinnant}
19943e519524SHoward Hinnant
19953e519524SHoward Hinnant// replace_copy
19963e519524SHoward Hinnant
19973e519524SHoward Hinnanttemplate <class _InputIterator, class _OutputIterator, class _Tp>
199812c7423fSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
19993e519524SHoward Hinnant_OutputIterator
20003e519524SHoward Hinnantreplace_copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result,
20013e519524SHoward Hinnant             const _Tp& __old_value, const _Tp& __new_value)
20023e519524SHoward Hinnant{
2003910285b2SEric Fiselier    for (; __first != __last; ++__first, (void) ++__result)
20043e519524SHoward Hinnant        if (*__first == __old_value)
20053e519524SHoward Hinnant            *__result = __new_value;
20063e519524SHoward Hinnant        else
20073e519524SHoward Hinnant            *__result = *__first;
20083e519524SHoward Hinnant    return __result;
20093e519524SHoward Hinnant}
20103e519524SHoward Hinnant
20113e519524SHoward Hinnant// replace_copy_if
20123e519524SHoward Hinnant
20133e519524SHoward Hinnanttemplate <class _InputIterator, class _OutputIterator, class _Predicate, class _Tp>
201412c7423fSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
20153e519524SHoward Hinnant_OutputIterator
20163e519524SHoward Hinnantreplace_copy_if(_InputIterator __first, _InputIterator __last, _OutputIterator __result,
20173e519524SHoward Hinnant                _Predicate __pred, const _Tp& __new_value)
20183e519524SHoward Hinnant{
2019910285b2SEric Fiselier    for (; __first != __last; ++__first, (void) ++__result)
20203e519524SHoward Hinnant        if (__pred(*__first))
20213e519524SHoward Hinnant            *__result = __new_value;
20223e519524SHoward Hinnant        else
20233e519524SHoward Hinnant            *__result = *__first;
20243e519524SHoward Hinnant    return __result;
20253e519524SHoward Hinnant}
20263e519524SHoward Hinnant
20273e519524SHoward Hinnant// fill_n
20283e519524SHoward Hinnant
20293e519524SHoward Hinnanttemplate <class _OutputIterator, class _Size, class _Tp>
20304bfb9313SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
20313e519524SHoward Hinnant_OutputIterator
20320f242beaSHoward Hinnant__fill_n(_OutputIterator __first, _Size __n, const _Tp& __value_)
20333e519524SHoward Hinnant{
2034910285b2SEric Fiselier    for (; __n > 0; ++__first, (void) --__n)
2035e4383379SHoward Hinnant        *__first = __value_;
20363e519524SHoward Hinnant    return __first;
20373e519524SHoward Hinnant}
20383e519524SHoward Hinnant
20393e519524SHoward Hinnanttemplate <class _OutputIterator, class _Size, class _Tp>
20404bfb9313SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
20413e519524SHoward Hinnant_OutputIterator
2042e4383379SHoward Hinnantfill_n(_OutputIterator __first, _Size __n, const _Tp& __value_)
20433e519524SHoward Hinnant{
2044c0428b3cSArthur O'Dwyer   return _VSTD::__fill_n(__first, _VSTD::__convert_to_integral(__n), __value_);
20453e519524SHoward Hinnant}
20463e519524SHoward Hinnant
20473e519524SHoward Hinnant// fill
20483e519524SHoward Hinnant
20493e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Tp>
20504bfb9313SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
20513e519524SHoward Hinnantvoid
2052e4383379SHoward Hinnant__fill(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, forward_iterator_tag)
20533e519524SHoward Hinnant{
20543e519524SHoward Hinnant    for (; __first != __last; ++__first)
2055e4383379SHoward Hinnant        *__first = __value_;
20563e519524SHoward Hinnant}
20573e519524SHoward Hinnant
20583e519524SHoward Hinnanttemplate <class _RandomAccessIterator, class _Tp>
20594bfb9313SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
20603e519524SHoward Hinnantvoid
2061e4383379SHoward Hinnant__fill(_RandomAccessIterator __first, _RandomAccessIterator __last, const _Tp& __value_, random_access_iterator_tag)
20623e519524SHoward Hinnant{
2063e4383379SHoward Hinnant    _VSTD::fill_n(__first, __last - __first, __value_);
20643e519524SHoward Hinnant}
20653e519524SHoward Hinnant
20663e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Tp>
20674bfb9313SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
20683e519524SHoward Hinnantvoid
2069e4383379SHoward Hinnantfill(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_)
20703e519524SHoward Hinnant{
2071e4383379SHoward Hinnant    _VSTD::__fill(__first, __last, __value_, typename iterator_traits<_ForwardIterator>::iterator_category());
20723e519524SHoward Hinnant}
20733e519524SHoward Hinnant
20743e519524SHoward Hinnant// generate
20753e519524SHoward Hinnant
20763e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Generator>
20774bfb9313SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
20783e519524SHoward Hinnantvoid
20793e519524SHoward Hinnantgenerate(_ForwardIterator __first, _ForwardIterator __last, _Generator __gen)
20803e519524SHoward Hinnant{
20813e519524SHoward Hinnant    for (; __first != __last; ++__first)
20823e519524SHoward Hinnant        *__first = __gen();
20833e519524SHoward Hinnant}
20843e519524SHoward Hinnant
20853e519524SHoward Hinnant// generate_n
20863e519524SHoward Hinnant
20873e519524SHoward Hinnanttemplate <class _OutputIterator, class _Size, class _Generator>
20884bfb9313SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
20893e519524SHoward Hinnant_OutputIterator
209051544023SEric Fiseliergenerate_n(_OutputIterator __first, _Size __orig_n, _Generator __gen)
20913e519524SHoward Hinnant{
2092c0428b3cSArthur O'Dwyer    typedef decltype(_VSTD::__convert_to_integral(__orig_n)) _IntegralSize;
209351544023SEric Fiselier    _IntegralSize __n = __orig_n;
2094910285b2SEric Fiselier    for (; __n > 0; ++__first, (void) --__n)
20953e519524SHoward Hinnant        *__first = __gen();
20963e519524SHoward Hinnant    return __first;
20973e519524SHoward Hinnant}
20983e519524SHoward Hinnant
20993e519524SHoward Hinnant// remove
21003e519524SHoward Hinnant
21013e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Tp>
21021362d7efSNico Weber_LIBCPP_NODISCARD_EXT _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
2103e4383379SHoward Hinnantremove(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_)
21043e519524SHoward Hinnant{
2105e4383379SHoward Hinnant    __first = _VSTD::find(__first, __last, __value_);
21063e519524SHoward Hinnant    if (__first != __last)
21073e519524SHoward Hinnant    {
21083e519524SHoward Hinnant        _ForwardIterator __i = __first;
21093e519524SHoward Hinnant        while (++__i != __last)
21103e519524SHoward Hinnant        {
2111e4383379SHoward Hinnant            if (!(*__i == __value_))
21123e519524SHoward Hinnant            {
2113ce48a113SHoward Hinnant                *__first = _VSTD::move(*__i);
21143e519524SHoward Hinnant                ++__first;
21153e519524SHoward Hinnant            }
21163e519524SHoward Hinnant        }
21173e519524SHoward Hinnant    }
21183e519524SHoward Hinnant    return __first;
21193e519524SHoward Hinnant}
21203e519524SHoward Hinnant
21213e519524SHoward Hinnant// remove_if
21223e519524SHoward Hinnant
21233e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Predicate>
21241362d7efSNico Weber_LIBCPP_NODISCARD_EXT _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
21253e519524SHoward Hinnantremove_if(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred)
21263e519524SHoward Hinnant{
2127ce48a113SHoward Hinnant    __first = _VSTD::find_if<_ForwardIterator, typename add_lvalue_reference<_Predicate>::type>
21283e519524SHoward Hinnant                           (__first, __last, __pred);
21293e519524SHoward Hinnant    if (__first != __last)
21303e519524SHoward Hinnant    {
21313e519524SHoward Hinnant        _ForwardIterator __i = __first;
21323e519524SHoward Hinnant        while (++__i != __last)
21333e519524SHoward Hinnant        {
21343e519524SHoward Hinnant            if (!__pred(*__i))
21353e519524SHoward Hinnant            {
2136ce48a113SHoward Hinnant                *__first = _VSTD::move(*__i);
21373e519524SHoward Hinnant                ++__first;
21383e519524SHoward Hinnant            }
21393e519524SHoward Hinnant        }
21403e519524SHoward Hinnant    }
21413e519524SHoward Hinnant    return __first;
21423e519524SHoward Hinnant}
21433e519524SHoward Hinnant
21443e519524SHoward Hinnant// remove_copy
21453e519524SHoward Hinnant
21463e519524SHoward Hinnanttemplate <class _InputIterator, class _OutputIterator, class _Tp>
2147e8ea8296SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
21483e519524SHoward Hinnant_OutputIterator
2149e4383379SHoward Hinnantremove_copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result, const _Tp& __value_)
21503e519524SHoward Hinnant{
21513e519524SHoward Hinnant    for (; __first != __last; ++__first)
21523e519524SHoward Hinnant    {
2153e4383379SHoward Hinnant        if (!(*__first == __value_))
21543e519524SHoward Hinnant        {
21553e519524SHoward Hinnant            *__result = *__first;
21563e519524SHoward Hinnant            ++__result;
21573e519524SHoward Hinnant        }
21583e519524SHoward Hinnant    }
21593e519524SHoward Hinnant    return __result;
21603e519524SHoward Hinnant}
21613e519524SHoward Hinnant
21623e519524SHoward Hinnant// remove_copy_if
21633e519524SHoward Hinnant
21643e519524SHoward Hinnanttemplate <class _InputIterator, class _OutputIterator, class _Predicate>
2165e8ea8296SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
21663e519524SHoward Hinnant_OutputIterator
21673e519524SHoward Hinnantremove_copy_if(_InputIterator __first, _InputIterator __last, _OutputIterator __result, _Predicate __pred)
21683e519524SHoward Hinnant{
21693e519524SHoward Hinnant    for (; __first != __last; ++__first)
21703e519524SHoward Hinnant    {
21713e519524SHoward Hinnant        if (!__pred(*__first))
21723e519524SHoward Hinnant        {
21733e519524SHoward Hinnant            *__result = *__first;
21743e519524SHoward Hinnant            ++__result;
21753e519524SHoward Hinnant        }
21763e519524SHoward Hinnant    }
21773e519524SHoward Hinnant    return __result;
21783e519524SHoward Hinnant}
21793e519524SHoward Hinnant
21803e519524SHoward Hinnant// unique
21813e519524SHoward Hinnant
21823e519524SHoward Hinnanttemplate <class _ForwardIterator, class _BinaryPredicate>
21831362d7efSNico Weber_LIBCPP_NODISCARD_EXT _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
21843e519524SHoward Hinnantunique(_ForwardIterator __first, _ForwardIterator __last, _BinaryPredicate __pred)
21853e519524SHoward Hinnant{
2186ce48a113SHoward Hinnant    __first = _VSTD::adjacent_find<_ForwardIterator, typename add_lvalue_reference<_BinaryPredicate>::type>
21873e519524SHoward Hinnant                                 (__first, __last, __pred);
21883e519524SHoward Hinnant    if (__first != __last)
21893e519524SHoward Hinnant    {
21903e519524SHoward Hinnant        // ...  a  a  ?  ...
21913e519524SHoward Hinnant        //      f     i
21923e519524SHoward Hinnant        _ForwardIterator __i = __first;
21933e519524SHoward Hinnant        for (++__i; ++__i != __last;)
21943e519524SHoward Hinnant            if (!__pred(*__first, *__i))
2195ce48a113SHoward Hinnant                *++__first = _VSTD::move(*__i);
21963e519524SHoward Hinnant        ++__first;
21973e519524SHoward Hinnant    }
21983e519524SHoward Hinnant    return __first;
21993e519524SHoward Hinnant}
22003e519524SHoward Hinnant
22013e519524SHoward Hinnanttemplate <class _ForwardIterator>
22021362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
22031362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
22043e519524SHoward Hinnant_ForwardIterator
22053e519524SHoward Hinnantunique(_ForwardIterator __first, _ForwardIterator __last)
22063e519524SHoward Hinnant{
22073e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator>::value_type __v;
2208ce48a113SHoward Hinnant    return _VSTD::unique(__first, __last, __equal_to<__v>());
22093e519524SHoward Hinnant}
22103e519524SHoward Hinnant
22113e519524SHoward Hinnant// unique_copy
22123e519524SHoward Hinnant
22133e519524SHoward Hinnanttemplate <class _BinaryPredicate, class _InputIterator, class _OutputIterator>
22144bfb9313SMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 _OutputIterator
22153e519524SHoward Hinnant__unique_copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result, _BinaryPredicate __pred,
22163e519524SHoward Hinnant              input_iterator_tag, output_iterator_tag)
22173e519524SHoward Hinnant{
22183e519524SHoward Hinnant    if (__first != __last)
22193e519524SHoward Hinnant    {
22203e519524SHoward Hinnant        typename iterator_traits<_InputIterator>::value_type __t(*__first);
22213e519524SHoward Hinnant        *__result = __t;
22223e519524SHoward Hinnant        ++__result;
22233e519524SHoward Hinnant        while (++__first != __last)
22243e519524SHoward Hinnant        {
22253e519524SHoward Hinnant            if (!__pred(__t, *__first))
22263e519524SHoward Hinnant            {
22273e519524SHoward Hinnant                __t = *__first;
22283e519524SHoward Hinnant                *__result = __t;
22293e519524SHoward Hinnant                ++__result;
22303e519524SHoward Hinnant            }
22313e519524SHoward Hinnant        }
22323e519524SHoward Hinnant    }
22333e519524SHoward Hinnant    return __result;
22343e519524SHoward Hinnant}
22353e519524SHoward Hinnant
22363e519524SHoward Hinnanttemplate <class _BinaryPredicate, class _ForwardIterator, class _OutputIterator>
22374bfb9313SMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 _OutputIterator
22383e519524SHoward Hinnant__unique_copy(_ForwardIterator __first, _ForwardIterator __last, _OutputIterator __result, _BinaryPredicate __pred,
22393e519524SHoward Hinnant              forward_iterator_tag, output_iterator_tag)
22403e519524SHoward Hinnant{
22413e519524SHoward Hinnant    if (__first != __last)
22423e519524SHoward Hinnant    {
22433e519524SHoward Hinnant        _ForwardIterator __i = __first;
22443e519524SHoward Hinnant        *__result = *__i;
22453e519524SHoward Hinnant        ++__result;
22463e519524SHoward Hinnant        while (++__first != __last)
22473e519524SHoward Hinnant        {
22483e519524SHoward Hinnant            if (!__pred(*__i, *__first))
22493e519524SHoward Hinnant            {
22503e519524SHoward Hinnant                *__result = *__first;
22513e519524SHoward Hinnant                ++__result;
22523e519524SHoward Hinnant                __i = __first;
22533e519524SHoward Hinnant            }
22543e519524SHoward Hinnant        }
22553e519524SHoward Hinnant    }
22563e519524SHoward Hinnant    return __result;
22573e519524SHoward Hinnant}
22583e519524SHoward Hinnant
22593e519524SHoward Hinnanttemplate <class _BinaryPredicate, class _InputIterator, class _ForwardIterator>
22604bfb9313SMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
22613e519524SHoward Hinnant__unique_copy(_InputIterator __first, _InputIterator __last, _ForwardIterator __result, _BinaryPredicate __pred,
22623e519524SHoward Hinnant              input_iterator_tag, forward_iterator_tag)
22633e519524SHoward Hinnant{
22643e519524SHoward Hinnant    if (__first != __last)
22653e519524SHoward Hinnant    {
22663e519524SHoward Hinnant        *__result = *__first;
22673e519524SHoward Hinnant        while (++__first != __last)
22683e519524SHoward Hinnant            if (!__pred(*__result, *__first))
22693e519524SHoward Hinnant                *++__result = *__first;
22703e519524SHoward Hinnant        ++__result;
22713e519524SHoward Hinnant    }
22723e519524SHoward Hinnant    return __result;
22733e519524SHoward Hinnant}
22743e519524SHoward Hinnant
22753e519524SHoward Hinnanttemplate <class _InputIterator, class _OutputIterator, class _BinaryPredicate>
22764bfb9313SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
22773e519524SHoward Hinnant_OutputIterator
22783e519524SHoward Hinnantunique_copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result, _BinaryPredicate __pred)
22793e519524SHoward Hinnant{
2280ce48a113SHoward Hinnant    return _VSTD::__unique_copy<typename add_lvalue_reference<_BinaryPredicate>::type>
22813e519524SHoward Hinnant                              (__first, __last, __result, __pred,
22823e519524SHoward Hinnant                               typename iterator_traits<_InputIterator>::iterator_category(),
22833e519524SHoward Hinnant                               typename iterator_traits<_OutputIterator>::iterator_category());
22843e519524SHoward Hinnant}
22853e519524SHoward Hinnant
22863e519524SHoward Hinnanttemplate <class _InputIterator, class _OutputIterator>
22874bfb9313SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
22883e519524SHoward Hinnant_OutputIterator
22893e519524SHoward Hinnantunique_copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
22903e519524SHoward Hinnant{
22913e519524SHoward Hinnant    typedef typename iterator_traits<_InputIterator>::value_type __v;
2292ce48a113SHoward Hinnant    return _VSTD::unique_copy(__first, __last, __result, __equal_to<__v>());
22933e519524SHoward Hinnant}
22943e519524SHoward Hinnant
22953e519524SHoward Hinnant// reverse
22963e519524SHoward Hinnant
22973e519524SHoward Hinnanttemplate <class _BidirectionalIterator>
2298f851db3dSArthur O'Dwyerinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
22993e519524SHoward Hinnantvoid
23003e519524SHoward Hinnant__reverse(_BidirectionalIterator __first, _BidirectionalIterator __last, bidirectional_iterator_tag)
23013e519524SHoward Hinnant{
23023e519524SHoward Hinnant    while (__first != __last)
23033e519524SHoward Hinnant    {
23043e519524SHoward Hinnant        if (__first == --__last)
23053e519524SHoward Hinnant            break;
2306def501d1SMarshall Clow        _VSTD::iter_swap(__first, __last);
23073e519524SHoward Hinnant        ++__first;
23083e519524SHoward Hinnant    }
23093e519524SHoward Hinnant}
23103e519524SHoward Hinnant
23113e519524SHoward Hinnanttemplate <class _RandomAccessIterator>
2312f851db3dSArthur O'Dwyerinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
23133e519524SHoward Hinnantvoid
23143e519524SHoward Hinnant__reverse(_RandomAccessIterator __first, _RandomAccessIterator __last, random_access_iterator_tag)
23153e519524SHoward Hinnant{
23163e519524SHoward Hinnant    if (__first != __last)
23173e519524SHoward Hinnant        for (; __first < --__last; ++__first)
2318def501d1SMarshall Clow            _VSTD::iter_swap(__first, __last);
23193e519524SHoward Hinnant}
23203e519524SHoward Hinnant
23213e519524SHoward Hinnanttemplate <class _BidirectionalIterator>
2322f851db3dSArthur O'Dwyerinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
23233e519524SHoward Hinnantvoid
23243e519524SHoward Hinnantreverse(_BidirectionalIterator __first, _BidirectionalIterator __last)
23253e519524SHoward Hinnant{
2326ce48a113SHoward Hinnant    _VSTD::__reverse(__first, __last, typename iterator_traits<_BidirectionalIterator>::iterator_category());
23273e519524SHoward Hinnant}
23283e519524SHoward Hinnant
23293e519524SHoward Hinnant// reverse_copy
23303e519524SHoward Hinnant
23313e519524SHoward Hinnanttemplate <class _BidirectionalIterator, class _OutputIterator>
2332e8ea8296SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
23333e519524SHoward Hinnant_OutputIterator
23343e519524SHoward Hinnantreverse_copy(_BidirectionalIterator __first, _BidirectionalIterator __last, _OutputIterator __result)
23353e519524SHoward Hinnant{
23363e519524SHoward Hinnant    for (; __first != __last; ++__result)
23373e519524SHoward Hinnant        *__result = *--__last;
23383e519524SHoward Hinnant    return __result;
23393e519524SHoward Hinnant}
23403e519524SHoward Hinnant
23413e519524SHoward Hinnant// rotate
23423e519524SHoward Hinnant
23433e519524SHoward Hinnanttemplate <class _ForwardIterator>
23443ed89b51Szoecarver_LIBCPP_CONSTEXPR_AFTER_CXX11 _ForwardIterator
2345aca09de3SHoward Hinnant__rotate_left(_ForwardIterator __first, _ForwardIterator __last)
23463e519524SHoward Hinnant{
2347aca09de3SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
2348aca09de3SHoward Hinnant    value_type __tmp = _VSTD::move(*__first);
2349aca09de3SHoward Hinnant    _ForwardIterator __lm1 = _VSTD::move(_VSTD::next(__first), __last, __first);
2350aca09de3SHoward Hinnant    *__lm1 = _VSTD::move(__tmp);
2351aca09de3SHoward Hinnant    return __lm1;
2352aca09de3SHoward Hinnant}
2353aca09de3SHoward Hinnant
2354aca09de3SHoward Hinnanttemplate <class _BidirectionalIterator>
23553ed89b51Szoecarver_LIBCPP_CONSTEXPR_AFTER_CXX11 _BidirectionalIterator
2356aca09de3SHoward Hinnant__rotate_right(_BidirectionalIterator __first, _BidirectionalIterator __last)
2357aca09de3SHoward Hinnant{
2358aca09de3SHoward Hinnant    typedef typename iterator_traits<_BidirectionalIterator>::value_type value_type;
2359aca09de3SHoward Hinnant    _BidirectionalIterator __lm1 = _VSTD::prev(__last);
2360aca09de3SHoward Hinnant    value_type __tmp = _VSTD::move(*__lm1);
2361aca09de3SHoward Hinnant    _BidirectionalIterator __fp1 = _VSTD::move_backward(__first, __lm1, __last);
2362aca09de3SHoward Hinnant    *__first = _VSTD::move(__tmp);
2363aca09de3SHoward Hinnant    return __fp1;
2364aca09de3SHoward Hinnant}
2365aca09de3SHoward Hinnant
2366aca09de3SHoward Hinnanttemplate <class _ForwardIterator>
23673ed89b51Szoecarver_LIBCPP_CONSTEXPR_AFTER_CXX14 _ForwardIterator
2368aca09de3SHoward Hinnant__rotate_forward(_ForwardIterator __first, _ForwardIterator __middle, _ForwardIterator __last)
2369aca09de3SHoward Hinnant{
23703e519524SHoward Hinnant    _ForwardIterator __i = __middle;
23713e519524SHoward Hinnant    while (true)
23723e519524SHoward Hinnant    {
23733e519524SHoward Hinnant        swap(*__first, *__i);
23743e519524SHoward Hinnant        ++__first;
23753e519524SHoward Hinnant        if (++__i == __last)
23763e519524SHoward Hinnant            break;
23773e519524SHoward Hinnant        if (__first == __middle)
23783e519524SHoward Hinnant            __middle = __i;
23793e519524SHoward Hinnant    }
23803e519524SHoward Hinnant    _ForwardIterator __r = __first;
23813e519524SHoward Hinnant    if (__first != __middle)
23823e519524SHoward Hinnant    {
23833e519524SHoward Hinnant        __i = __middle;
23843e519524SHoward Hinnant        while (true)
23853e519524SHoward Hinnant        {
23863e519524SHoward Hinnant            swap(*__first, *__i);
23873e519524SHoward Hinnant            ++__first;
23883e519524SHoward Hinnant            if (++__i == __last)
23893e519524SHoward Hinnant            {
23903e519524SHoward Hinnant                if (__first == __middle)
23913e519524SHoward Hinnant                    break;
23923e519524SHoward Hinnant                __i = __middle;
23933e519524SHoward Hinnant            }
23943e519524SHoward Hinnant            else if (__first == __middle)
23953e519524SHoward Hinnant                __middle = __i;
23963e519524SHoward Hinnant        }
23973e519524SHoward Hinnant    }
23983e519524SHoward Hinnant    return __r;
23993e519524SHoward Hinnant}
24003e519524SHoward Hinnant
24013e519524SHoward Hinnanttemplate<typename _Integral>
24023e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
24033ed89b51Szoecarver_LIBCPP_CONSTEXPR_AFTER_CXX14 _Integral
240419b4035fSMarshall Clow__algo_gcd(_Integral __x, _Integral __y)
24053e519524SHoward Hinnant{
24063e519524SHoward Hinnant    do
24073e519524SHoward Hinnant    {
24083e519524SHoward Hinnant        _Integral __t = __x % __y;
24093e519524SHoward Hinnant        __x = __y;
24103e519524SHoward Hinnant        __y = __t;
24113e519524SHoward Hinnant    } while (__y);
24123e519524SHoward Hinnant    return __x;
24133e519524SHoward Hinnant}
24143e519524SHoward Hinnant
24153e519524SHoward Hinnanttemplate<typename _RandomAccessIterator>
24163ed89b51Szoecarver_LIBCPP_CONSTEXPR_AFTER_CXX14 _RandomAccessIterator
2417aca09de3SHoward Hinnant__rotate_gcd(_RandomAccessIterator __first, _RandomAccessIterator __middle, _RandomAccessIterator __last)
24183e519524SHoward Hinnant{
24193e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
24203e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
24213e519524SHoward Hinnant
24223e519524SHoward Hinnant    const difference_type __m1 = __middle - __first;
24233e519524SHoward Hinnant    const difference_type __m2 = __last - __middle;
24243e519524SHoward Hinnant    if (__m1 == __m2)
24253e519524SHoward Hinnant    {
2426ce48a113SHoward Hinnant        _VSTD::swap_ranges(__first, __middle, __middle);
24273e519524SHoward Hinnant        return __middle;
24283e519524SHoward Hinnant    }
242919b4035fSMarshall Clow    const difference_type __g = _VSTD::__algo_gcd(__m1, __m2);
24303e519524SHoward Hinnant    for (_RandomAccessIterator __p = __first + __g; __p != __first;)
24313e519524SHoward Hinnant    {
2432aca09de3SHoward Hinnant        value_type __t(_VSTD::move(*--__p));
24333e519524SHoward Hinnant        _RandomAccessIterator __p1 = __p;
24343e519524SHoward Hinnant        _RandomAccessIterator __p2 = __p1 + __m1;
24353e519524SHoward Hinnant        do
24363e519524SHoward Hinnant        {
2437aca09de3SHoward Hinnant            *__p1 = _VSTD::move(*__p2);
24383e519524SHoward Hinnant            __p1 = __p2;
24393e519524SHoward Hinnant            const difference_type __d = __last - __p2;
24403e519524SHoward Hinnant            if (__m1 < __d)
24413e519524SHoward Hinnant                __p2 += __m1;
24423e519524SHoward Hinnant            else
24433e519524SHoward Hinnant                __p2 = __first + (__m1 - __d);
24443e519524SHoward Hinnant        } while (__p2 != __p);
2445aca09de3SHoward Hinnant        *__p1 = _VSTD::move(__t);
24463e519524SHoward Hinnant    }
24473e519524SHoward Hinnant    return __first + __m2;
24483e519524SHoward Hinnant}
24493e519524SHoward Hinnant
24503e519524SHoward Hinnanttemplate <class _ForwardIterator>
24513e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
24523ed89b51Szoecarver_LIBCPP_CONSTEXPR_AFTER_CXX11 _ForwardIterator
2453aca09de3SHoward Hinnant__rotate(_ForwardIterator __first, _ForwardIterator __middle, _ForwardIterator __last,
2454aca09de3SHoward Hinnant         _VSTD::forward_iterator_tag)
2455aca09de3SHoward Hinnant{
2456aca09de3SHoward Hinnant    typedef typename _VSTD::iterator_traits<_ForwardIterator>::value_type value_type;
2457aca09de3SHoward Hinnant    if (_VSTD::is_trivially_move_assignable<value_type>::value)
2458aca09de3SHoward Hinnant    {
2459aca09de3SHoward Hinnant        if (_VSTD::next(__first) == __middle)
2460aca09de3SHoward Hinnant            return _VSTD::__rotate_left(__first, __last);
2461aca09de3SHoward Hinnant    }
2462aca09de3SHoward Hinnant    return _VSTD::__rotate_forward(__first, __middle, __last);
2463aca09de3SHoward Hinnant}
2464aca09de3SHoward Hinnant
2465aca09de3SHoward Hinnanttemplate <class _BidirectionalIterator>
2466aca09de3SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
24673ed89b51Szoecarver_LIBCPP_CONSTEXPR_AFTER_CXX11 _BidirectionalIterator
2468aca09de3SHoward Hinnant__rotate(_BidirectionalIterator __first, _BidirectionalIterator __middle, _BidirectionalIterator __last,
2469aca09de3SHoward Hinnant         _VSTD::bidirectional_iterator_tag)
2470aca09de3SHoward Hinnant{
2471aca09de3SHoward Hinnant    typedef typename _VSTD::iterator_traits<_BidirectionalIterator>::value_type value_type;
2472aca09de3SHoward Hinnant    if (_VSTD::is_trivially_move_assignable<value_type>::value)
2473aca09de3SHoward Hinnant    {
2474aca09de3SHoward Hinnant        if (_VSTD::next(__first) == __middle)
2475aca09de3SHoward Hinnant            return _VSTD::__rotate_left(__first, __last);
2476aca09de3SHoward Hinnant        if (_VSTD::next(__middle) == __last)
2477aca09de3SHoward Hinnant            return _VSTD::__rotate_right(__first, __last);
2478aca09de3SHoward Hinnant    }
2479aca09de3SHoward Hinnant    return _VSTD::__rotate_forward(__first, __middle, __last);
2480aca09de3SHoward Hinnant}
2481aca09de3SHoward Hinnant
2482aca09de3SHoward Hinnanttemplate <class _RandomAccessIterator>
2483aca09de3SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
24843ed89b51Szoecarver_LIBCPP_CONSTEXPR_AFTER_CXX11 _RandomAccessIterator
2485aca09de3SHoward Hinnant__rotate(_RandomAccessIterator __first, _RandomAccessIterator __middle, _RandomAccessIterator __last,
2486aca09de3SHoward Hinnant         _VSTD::random_access_iterator_tag)
2487aca09de3SHoward Hinnant{
2488aca09de3SHoward Hinnant    typedef typename _VSTD::iterator_traits<_RandomAccessIterator>::value_type value_type;
2489aca09de3SHoward Hinnant    if (_VSTD::is_trivially_move_assignable<value_type>::value)
2490aca09de3SHoward Hinnant    {
2491aca09de3SHoward Hinnant        if (_VSTD::next(__first) == __middle)
2492aca09de3SHoward Hinnant            return _VSTD::__rotate_left(__first, __last);
2493aca09de3SHoward Hinnant        if (_VSTD::next(__middle) == __last)
2494aca09de3SHoward Hinnant            return _VSTD::__rotate_right(__first, __last);
2495aca09de3SHoward Hinnant        return _VSTD::__rotate_gcd(__first, __middle, __last);
2496aca09de3SHoward Hinnant    }
2497aca09de3SHoward Hinnant    return _VSTD::__rotate_forward(__first, __middle, __last);
2498aca09de3SHoward Hinnant}
2499aca09de3SHoward Hinnant
2500aca09de3SHoward Hinnanttemplate <class _ForwardIterator>
2501aca09de3SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
25023ed89b51Szoecarver_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
25033e519524SHoward Hinnantrotate(_ForwardIterator __first, _ForwardIterator __middle, _ForwardIterator __last)
25043e519524SHoward Hinnant{
2505aca09de3SHoward Hinnant    if (__first == __middle)
2506aca09de3SHoward Hinnant        return __last;
2507aca09de3SHoward Hinnant    if (__middle == __last)
2508aca09de3SHoward Hinnant        return __first;
2509ce48a113SHoward Hinnant    return _VSTD::__rotate(__first, __middle, __last,
2510aca09de3SHoward Hinnant                           typename _VSTD::iterator_traits<_ForwardIterator>::iterator_category());
25113e519524SHoward Hinnant}
25123e519524SHoward Hinnant
25133e519524SHoward Hinnant// rotate_copy
25143e519524SHoward Hinnant
25153e519524SHoward Hinnanttemplate <class _ForwardIterator, class _OutputIterator>
2516b552a302SNicholas-Baroninline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
25173e519524SHoward Hinnant_OutputIterator
25183e519524SHoward Hinnantrotate_copy(_ForwardIterator __first, _ForwardIterator __middle, _ForwardIterator __last, _OutputIterator __result)
25193e519524SHoward Hinnant{
2520ce48a113SHoward Hinnant    return _VSTD::copy(__first, __middle, _VSTD::copy(__middle, __last, __result));
25213e519524SHoward Hinnant}
25223e519524SHoward Hinnant
25233e519524SHoward Hinnant// min_element
25243e519524SHoward Hinnant
25253e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Compare>
25261362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
25271362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
25283e519524SHoward Hinnant_ForwardIterator
25290b0671aeSMarshall Clowmin_element(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp)
25303e519524SHoward Hinnant{
2531f82dba01SEric Fiselier    static_assert(__is_cpp17_forward_iterator<_ForwardIterator>::value,
2532a60d7facSEric Fiselier        "std::min_element requires a ForwardIterator");
25333e519524SHoward Hinnant    if (__first != __last)
25343e519524SHoward Hinnant    {
25353e519524SHoward Hinnant        _ForwardIterator __i = __first;
25363e519524SHoward Hinnant        while (++__i != __last)
25373e519524SHoward Hinnant            if (__comp(*__i, *__first))
25383e519524SHoward Hinnant                __first = __i;
25393e519524SHoward Hinnant    }
25403e519524SHoward Hinnant    return __first;
25413e519524SHoward Hinnant}
25423e519524SHoward Hinnant
25433e519524SHoward Hinnanttemplate <class _ForwardIterator>
25441362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
25451362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
25463e519524SHoward Hinnant_ForwardIterator
25473e519524SHoward Hinnantmin_element(_ForwardIterator __first, _ForwardIterator __last)
25483e519524SHoward Hinnant{
25490b0671aeSMarshall Clow    return _VSTD::min_element(__first, __last,
25504eb27b79SHoward Hinnant              __less<typename iterator_traits<_ForwardIterator>::value_type>());
25514eb27b79SHoward Hinnant}
25524eb27b79SHoward Hinnant
25534eb27b79SHoward Hinnant// min
25544eb27b79SHoward Hinnant
25554eb27b79SHoward Hinnanttemplate <class _Tp, class _Compare>
25561362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
25571362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
25584eb27b79SHoward Hinnantconst _Tp&
25594eb27b79SHoward Hinnantmin(const _Tp& __a, const _Tp& __b, _Compare __comp)
25604eb27b79SHoward Hinnant{
25614eb27b79SHoward Hinnant    return __comp(__b, __a) ? __b : __a;
25624eb27b79SHoward Hinnant}
25634eb27b79SHoward Hinnant
25644eb27b79SHoward Hinnanttemplate <class _Tp>
25651362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
25661362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
25674eb27b79SHoward Hinnantconst _Tp&
25684eb27b79SHoward Hinnantmin(const _Tp& __a, const _Tp& __b)
25694eb27b79SHoward Hinnant{
2570ce48a113SHoward Hinnant    return _VSTD::min(__a, __b, __less<_Tp>());
25714eb27b79SHoward Hinnant}
25724eb27b79SHoward Hinnant
2573ddda456aSEric Fiselier#ifndef _LIBCPP_CXX03_LANG
257454976f26SHoward Hinnant
25754eb27b79SHoward Hinnanttemplate<class _Tp, class _Compare>
25761362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
25771362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
25784eb27b79SHoward Hinnant_Tp
25794eb27b79SHoward Hinnantmin(initializer_list<_Tp> __t, _Compare __comp)
25804eb27b79SHoward Hinnant{
25810b0671aeSMarshall Clow    return *_VSTD::min_element(__t.begin(), __t.end(), __comp);
25824eb27b79SHoward Hinnant}
25834eb27b79SHoward Hinnant
25844eb27b79SHoward Hinnanttemplate<class _Tp>
25851362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
25861362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
25874eb27b79SHoward Hinnant_Tp
25884eb27b79SHoward Hinnantmin(initializer_list<_Tp> __t)
25894eb27b79SHoward Hinnant{
25900b0671aeSMarshall Clow    return *_VSTD::min_element(__t.begin(), __t.end(), __less<_Tp>());
25913e519524SHoward Hinnant}
25923e519524SHoward Hinnant
2593ddda456aSEric Fiselier#endif  // _LIBCPP_CXX03_LANG
259454976f26SHoward Hinnant
25953e519524SHoward Hinnant// max_element
25963e519524SHoward Hinnant
25973e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Compare>
25981362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
25991362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
26003e519524SHoward Hinnant_ForwardIterator
26010b0671aeSMarshall Clowmax_element(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp)
26023e519524SHoward Hinnant{
2603f82dba01SEric Fiselier    static_assert(__is_cpp17_forward_iterator<_ForwardIterator>::value,
2604a60d7facSEric Fiselier        "std::max_element requires a ForwardIterator");
26053e519524SHoward Hinnant    if (__first != __last)
26063e519524SHoward Hinnant    {
26073e519524SHoward Hinnant        _ForwardIterator __i = __first;
26083e519524SHoward Hinnant        while (++__i != __last)
26093e519524SHoward Hinnant            if (__comp(*__first, *__i))
26103e519524SHoward Hinnant                __first = __i;
26113e519524SHoward Hinnant    }
26123e519524SHoward Hinnant    return __first;
26133e519524SHoward Hinnant}
26143e519524SHoward Hinnant
26159d67c6d5SMarshall Clow
26163e519524SHoward Hinnanttemplate <class _ForwardIterator>
26171362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
26181362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
26193e519524SHoward Hinnant_ForwardIterator
26203e519524SHoward Hinnantmax_element(_ForwardIterator __first, _ForwardIterator __last)
26213e519524SHoward Hinnant{
26220b0671aeSMarshall Clow    return _VSTD::max_element(__first, __last,
26234eb27b79SHoward Hinnant              __less<typename iterator_traits<_ForwardIterator>::value_type>());
26244eb27b79SHoward Hinnant}
26254eb27b79SHoward Hinnant
26264eb27b79SHoward Hinnant// max
26274eb27b79SHoward Hinnant
26284eb27b79SHoward Hinnanttemplate <class _Tp, class _Compare>
26291362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
26301362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
26314eb27b79SHoward Hinnantconst _Tp&
26324eb27b79SHoward Hinnantmax(const _Tp& __a, const _Tp& __b, _Compare __comp)
26334eb27b79SHoward Hinnant{
26344eb27b79SHoward Hinnant    return __comp(__a, __b) ? __b : __a;
26354eb27b79SHoward Hinnant}
26364eb27b79SHoward Hinnant
26374eb27b79SHoward Hinnanttemplate <class _Tp>
26381362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
26391362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
26404eb27b79SHoward Hinnantconst _Tp&
26414eb27b79SHoward Hinnantmax(const _Tp& __a, const _Tp& __b)
26424eb27b79SHoward Hinnant{
2643ce48a113SHoward Hinnant    return _VSTD::max(__a, __b, __less<_Tp>());
26444eb27b79SHoward Hinnant}
26454eb27b79SHoward Hinnant
2646ddda456aSEric Fiselier#ifndef _LIBCPP_CXX03_LANG
264754976f26SHoward Hinnant
26484eb27b79SHoward Hinnanttemplate<class _Tp, class _Compare>
26491362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
26501362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
26514eb27b79SHoward Hinnant_Tp
26524eb27b79SHoward Hinnantmax(initializer_list<_Tp> __t, _Compare __comp)
26534eb27b79SHoward Hinnant{
26540b0671aeSMarshall Clow    return *_VSTD::max_element(__t.begin(), __t.end(), __comp);
26554eb27b79SHoward Hinnant}
26564eb27b79SHoward Hinnant
26574eb27b79SHoward Hinnanttemplate<class _Tp>
26581362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
26591362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
26604eb27b79SHoward Hinnant_Tp
26614eb27b79SHoward Hinnantmax(initializer_list<_Tp> __t)
26624eb27b79SHoward Hinnant{
26630b0671aeSMarshall Clow    return *_VSTD::max_element(__t.begin(), __t.end(), __less<_Tp>());
26643e519524SHoward Hinnant}
26653e519524SHoward Hinnant
2666ddda456aSEric Fiselier#endif  // _LIBCPP_CXX03_LANG
266754976f26SHoward Hinnant
2668146c14acSMarshall Clow#if _LIBCPP_STD_VER > 14
2669146c14acSMarshall Clow// clamp
2670146c14acSMarshall Clowtemplate<class _Tp, class _Compare>
26711362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
26721362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
2673146c14acSMarshall Clowconst _Tp&
2674146c14acSMarshall Clowclamp(const _Tp& __v, const _Tp& __lo, const _Tp& __hi, _Compare __comp)
2675146c14acSMarshall Clow{
2676146c14acSMarshall Clow    _LIBCPP_ASSERT(!__comp(__hi, __lo), "Bad bounds passed to std::clamp");
2677146c14acSMarshall Clow    return __comp(__v, __lo) ? __lo : __comp(__hi, __v) ? __hi : __v;
2678146c14acSMarshall Clow
2679146c14acSMarshall Clow}
2680146c14acSMarshall Clow
2681146c14acSMarshall Clowtemplate<class _Tp>
26821362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
26831362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
2684146c14acSMarshall Clowconst _Tp&
2685146c14acSMarshall Clowclamp(const _Tp& __v, const _Tp& __lo, const _Tp& __hi)
2686146c14acSMarshall Clow{
2687146c14acSMarshall Clow    return _VSTD::clamp(__v, __lo, __hi, __less<_Tp>());
2688146c14acSMarshall Clow}
2689146c14acSMarshall Clow#endif
2690146c14acSMarshall Clow
26913e519524SHoward Hinnant// minmax_element
26923e519524SHoward Hinnant
26933e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Compare>
26941362d7efSNico Weber_LIBCPP_NODISCARD_EXT _LIBCPP_CONSTEXPR_AFTER_CXX11
2695d586f92cSArthur O'Dwyerpair<_ForwardIterator, _ForwardIterator>
26963e519524SHoward Hinnantminmax_element(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp)
26973e519524SHoward Hinnant{
2698f82dba01SEric Fiselier  static_assert(__is_cpp17_forward_iterator<_ForwardIterator>::value,
2699a60d7facSEric Fiselier        "std::minmax_element requires a ForwardIterator");
2700d586f92cSArthur O'Dwyer  pair<_ForwardIterator, _ForwardIterator> __result(__first, __first);
27013e519524SHoward Hinnant  if (__first != __last)
27023e519524SHoward Hinnant  {
27033e519524SHoward Hinnant      if (++__first != __last)
27043e519524SHoward Hinnant      {
27053e519524SHoward Hinnant          if (__comp(*__first, *__result.first))
27063e519524SHoward Hinnant              __result.first = __first;
27073e519524SHoward Hinnant          else
27083e519524SHoward Hinnant              __result.second = __first;
27093e519524SHoward Hinnant          while (++__first != __last)
27103e519524SHoward Hinnant          {
27113e519524SHoward Hinnant              _ForwardIterator __i = __first;
27123e519524SHoward Hinnant              if (++__first == __last)
27133e519524SHoward Hinnant              {
27143e519524SHoward Hinnant                  if (__comp(*__i, *__result.first))
27153e519524SHoward Hinnant                      __result.first = __i;
27163e519524SHoward Hinnant                  else if (!__comp(*__i, *__result.second))
27173e519524SHoward Hinnant                      __result.second = __i;
27183e519524SHoward Hinnant                  break;
27193e519524SHoward Hinnant              }
27203e519524SHoward Hinnant              else
27213e519524SHoward Hinnant              {
27223e519524SHoward Hinnant                  if (__comp(*__first, *__i))
27233e519524SHoward Hinnant                  {
27243e519524SHoward Hinnant                      if (__comp(*__first, *__result.first))
27253e519524SHoward Hinnant                          __result.first = __first;
27263e519524SHoward Hinnant                      if (!__comp(*__i, *__result.second))
27273e519524SHoward Hinnant                          __result.second = __i;
27283e519524SHoward Hinnant                  }
27293e519524SHoward Hinnant                  else
27303e519524SHoward Hinnant                  {
27313e519524SHoward Hinnant                      if (__comp(*__i, *__result.first))
27323e519524SHoward Hinnant                          __result.first = __i;
27333e519524SHoward Hinnant                      if (!__comp(*__first, *__result.second))
27343e519524SHoward Hinnant                          __result.second = __first;
27353e519524SHoward Hinnant                  }
27363e519524SHoward Hinnant              }
27373e519524SHoward Hinnant          }
27383e519524SHoward Hinnant      }
27393e519524SHoward Hinnant  }
27403e519524SHoward Hinnant  return __result;
27413e519524SHoward Hinnant}
27423e519524SHoward Hinnant
27433e519524SHoward Hinnanttemplate <class _ForwardIterator>
27441362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
27451362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
2746d586f92cSArthur O'Dwyerpair<_ForwardIterator, _ForwardIterator>
27473e519524SHoward Hinnantminmax_element(_ForwardIterator __first, _ForwardIterator __last)
27483e519524SHoward Hinnant{
27499d67c6d5SMarshall Clow    return _VSTD::minmax_element(__first, __last,
27509d67c6d5SMarshall Clow              __less<typename iterator_traits<_ForwardIterator>::value_type>());
27513e519524SHoward Hinnant}
27523e519524SHoward Hinnant
27534eb27b79SHoward Hinnant// minmax
27544eb27b79SHoward Hinnant
27554eb27b79SHoward Hinnanttemplate<class _Tp, class _Compare>
27561362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
27571362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
27584eb27b79SHoward Hinnantpair<const _Tp&, const _Tp&>
27594eb27b79SHoward Hinnantminmax(const _Tp& __a, const _Tp& __b, _Compare __comp)
27604eb27b79SHoward Hinnant{
27614eb27b79SHoward Hinnant    return __comp(__b, __a) ? pair<const _Tp&, const _Tp&>(__b, __a) :
27624eb27b79SHoward Hinnant                              pair<const _Tp&, const _Tp&>(__a, __b);
27634eb27b79SHoward Hinnant}
27644eb27b79SHoward Hinnant
27654eb27b79SHoward Hinnanttemplate<class _Tp>
27661362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
27671362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
27684eb27b79SHoward Hinnantpair<const _Tp&, const _Tp&>
27694eb27b79SHoward Hinnantminmax(const _Tp& __a, const _Tp& __b)
27704eb27b79SHoward Hinnant{
2771ce48a113SHoward Hinnant    return _VSTD::minmax(__a, __b, __less<_Tp>());
27724eb27b79SHoward Hinnant}
27734eb27b79SHoward Hinnant
2774ddda456aSEric Fiselier#ifndef _LIBCPP_CXX03_LANG
277554976f26SHoward Hinnant
27764eb27b79SHoward Hinnanttemplate<class _Tp, class _Compare>
27771362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
27781362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
27794eb27b79SHoward Hinnantpair<_Tp, _Tp>
27804eb27b79SHoward Hinnantminmax(initializer_list<_Tp> __t, _Compare __comp)
27814eb27b79SHoward Hinnant{
27829d67c6d5SMarshall Clow    typedef typename initializer_list<_Tp>::const_iterator _Iter;
27839d67c6d5SMarshall Clow    _Iter __first = __t.begin();
27849d67c6d5SMarshall Clow    _Iter __last  = __t.end();
2785d586f92cSArthur O'Dwyer    pair<_Tp, _Tp> __result(*__first, *__first);
27869d67c6d5SMarshall Clow
27879d67c6d5SMarshall Clow    ++__first;
27889d67c6d5SMarshall Clow    if (__t.size() % 2 == 0)
27899d67c6d5SMarshall Clow    {
27909d67c6d5SMarshall Clow        if (__comp(*__first,  __result.first))
27919d67c6d5SMarshall Clow            __result.first  = *__first;
27929d67c6d5SMarshall Clow        else
27939d67c6d5SMarshall Clow            __result.second = *__first;
27949d67c6d5SMarshall Clow        ++__first;
27959d67c6d5SMarshall Clow    }
27969d67c6d5SMarshall Clow
27979d67c6d5SMarshall Clow    while (__first != __last)
27989d67c6d5SMarshall Clow    {
27999d67c6d5SMarshall Clow        _Tp __prev = *__first++;
2800002144f6SMarshall Clow        if (__comp(*__first, __prev)) {
2801002144f6SMarshall Clow            if ( __comp(*__first, __result.first)) __result.first  = *__first;
2802002144f6SMarshall Clow            if (!__comp(__prev, __result.second))  __result.second = __prev;
28039d67c6d5SMarshall Clow            }
28049d67c6d5SMarshall Clow        else {
2805002144f6SMarshall Clow            if ( __comp(__prev, __result.first))    __result.first  = __prev;
2806002144f6SMarshall Clow            if (!__comp(*__first, __result.second)) __result.second = *__first;
28079d67c6d5SMarshall Clow            }
28089d67c6d5SMarshall Clow
28099d67c6d5SMarshall Clow        __first++;
28109d67c6d5SMarshall Clow    }
28119d67c6d5SMarshall Clow    return __result;
28129d67c6d5SMarshall Clow}
28139d67c6d5SMarshall Clow
28149d67c6d5SMarshall Clowtemplate<class _Tp>
28151362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
28161362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
28179d67c6d5SMarshall Clowpair<_Tp, _Tp>
28189d67c6d5SMarshall Clowminmax(initializer_list<_Tp> __t)
28199d67c6d5SMarshall Clow{
28209d67c6d5SMarshall Clow    return _VSTD::minmax(__t, __less<_Tp>());
28214eb27b79SHoward Hinnant}
28224eb27b79SHoward Hinnant
2823ddda456aSEric Fiselier#endif  // _LIBCPP_CXX03_LANG
282454976f26SHoward Hinnant
28253e519524SHoward Hinnant// random_shuffle
28263e519524SHoward Hinnant
2827f9d540b0SHoward Hinnant// __independent_bits_engine
2828f9d540b0SHoward Hinnant
2829c003db1fSHoward Hinnanttemplate <unsigned long long _Xp, size_t _Rp>
2830f9d540b0SHoward Hinnantstruct __log2_imp
28313e519524SHoward Hinnant{
2832c003db1fSHoward Hinnant    static const size_t value = _Xp & ((unsigned long long)(1) << _Rp) ? _Rp
2833c003db1fSHoward Hinnant                                           : __log2_imp<_Xp, _Rp - 1>::value;
28343e519524SHoward Hinnant};
28353e519524SHoward Hinnant
2836c003db1fSHoward Hinnanttemplate <unsigned long long _Xp>
2837c003db1fSHoward Hinnantstruct __log2_imp<_Xp, 0>
28383e519524SHoward Hinnant{
2839f9d540b0SHoward Hinnant    static const size_t value = 0;
28403e519524SHoward Hinnant};
28413e519524SHoward Hinnant
2842c003db1fSHoward Hinnanttemplate <size_t _Rp>
2843c003db1fSHoward Hinnantstruct __log2_imp<0, _Rp>
28443e519524SHoward Hinnant{
2845c003db1fSHoward Hinnant    static const size_t value = _Rp + 1;
28463e519524SHoward Hinnant};
28473e519524SHoward Hinnant
284889918caaSEric Fiseliertemplate <class _UIntType, _UIntType _Xp>
2849f9d540b0SHoward Hinnantstruct __log2
28503e519524SHoward Hinnant{
2851c003db1fSHoward Hinnant    static const size_t value = __log2_imp<_Xp,
285289918caaSEric Fiselier                                         sizeof(_UIntType) * __CHAR_BIT__ - 1>::value;
28533e519524SHoward Hinnant};
28543e519524SHoward Hinnant
2855f9d540b0SHoward Hinnanttemplate<class _Engine, class _UIntType>
2856f9d540b0SHoward Hinnantclass __independent_bits_engine
28573e519524SHoward Hinnant{
2858f9d540b0SHoward Hinnantpublic:
2859f9d540b0SHoward Hinnant    // types
2860f9d540b0SHoward Hinnant    typedef _UIntType result_type;
2861f9d540b0SHoward Hinnant
2862f9d540b0SHoward Hinnantprivate:
2863f9d540b0SHoward Hinnant    typedef typename _Engine::result_type _Engine_result_type;
2864f9d540b0SHoward Hinnant    typedef typename conditional
2865f9d540b0SHoward Hinnant        <
2866f9d540b0SHoward Hinnant            sizeof(_Engine_result_type) <= sizeof(result_type),
2867f9d540b0SHoward Hinnant                result_type,
2868f9d540b0SHoward Hinnant                _Engine_result_type
2869f9d540b0SHoward Hinnant        >::type _Working_result_type;
2870f9d540b0SHoward Hinnant
2871f9d540b0SHoward Hinnant    _Engine& __e_;
2872f9d540b0SHoward Hinnant    size_t __w_;
2873f9d540b0SHoward Hinnant    size_t __w0_;
2874f9d540b0SHoward Hinnant    size_t __n_;
2875f9d540b0SHoward Hinnant    size_t __n0_;
2876f9d540b0SHoward Hinnant    _Working_result_type __y0_;
2877f9d540b0SHoward Hinnant    _Working_result_type __y1_;
2878f9d540b0SHoward Hinnant    _Engine_result_type __mask0_;
2879f9d540b0SHoward Hinnant    _Engine_result_type __mask1_;
2880f9d540b0SHoward Hinnant
2881ddda456aSEric Fiselier#ifdef _LIBCPP_CXX03_LANG
2882c003db1fSHoward Hinnant    static const _Working_result_type _Rp = _Engine::_Max - _Engine::_Min
2883f9d540b0SHoward Hinnant                                          + _Working_result_type(1);
2884e386b7b3SHoward Hinnant#else
2885e386b7b3SHoward Hinnant    static _LIBCPP_CONSTEXPR const _Working_result_type _Rp = _Engine::max() - _Engine::min()
2886e386b7b3SHoward Hinnant                                                      + _Working_result_type(1);
2887e386b7b3SHoward Hinnant#endif
2888e386b7b3SHoward Hinnant    static _LIBCPP_CONSTEXPR const size_t __m = __log2<_Working_result_type, _Rp>::value;
2889e386b7b3SHoward Hinnant    static _LIBCPP_CONSTEXPR const size_t _WDt = numeric_limits<_Working_result_type>::digits;
2890e386b7b3SHoward Hinnant    static _LIBCPP_CONSTEXPR const size_t _EDt = numeric_limits<_Engine_result_type>::digits;
2891f9d540b0SHoward Hinnant
2892f9d540b0SHoward Hinnantpublic:
2893f9d540b0SHoward Hinnant    // constructors and seeding functions
2894f9d540b0SHoward Hinnant    __independent_bits_engine(_Engine& __e, size_t __w);
2895f9d540b0SHoward Hinnant
2896f9d540b0SHoward Hinnant    // generating functions
2897c003db1fSHoward Hinnant    result_type operator()() {return __eval(integral_constant<bool, _Rp != 0>());}
2898f9d540b0SHoward Hinnant
2899f9d540b0SHoward Hinnantprivate:
290008bba64aSMarshall Clow    result_type __eval(false_type);
290108bba64aSMarshall Clow    result_type __eval(true_type);
2902f9d540b0SHoward Hinnant};
2903f9d540b0SHoward Hinnant
2904f9d540b0SHoward Hinnanttemplate<class _Engine, class _UIntType>
2905f9d540b0SHoward Hinnant__independent_bits_engine<_Engine, _UIntType>
2906f9d540b0SHoward Hinnant    ::__independent_bits_engine(_Engine& __e, size_t __w)
2907f9d540b0SHoward Hinnant        : __e_(__e),
2908f9d540b0SHoward Hinnant          __w_(__w)
2909f9d540b0SHoward Hinnant{
2910f9d540b0SHoward Hinnant    __n_ = __w_ / __m + (__w_ % __m != 0);
2911f9d540b0SHoward Hinnant    __w0_ = __w_ / __n_;
2912c003db1fSHoward Hinnant    if (_Rp == 0)
2913c003db1fSHoward Hinnant        __y0_ = _Rp;
2914f9d540b0SHoward Hinnant    else if (__w0_ < _WDt)
2915c003db1fSHoward Hinnant        __y0_ = (_Rp >> __w0_) << __w0_;
2916f9d540b0SHoward Hinnant    else
2917f9d540b0SHoward Hinnant        __y0_ = 0;
2918c003db1fSHoward Hinnant    if (_Rp - __y0_ > __y0_ / __n_)
2919f9d540b0SHoward Hinnant    {
2920f9d540b0SHoward Hinnant        ++__n_;
2921f9d540b0SHoward Hinnant        __w0_ = __w_ / __n_;
2922f9d540b0SHoward Hinnant        if (__w0_ < _WDt)
2923c003db1fSHoward Hinnant            __y0_ = (_Rp >> __w0_) << __w0_;
2924f9d540b0SHoward Hinnant        else
2925f9d540b0SHoward Hinnant            __y0_ = 0;
2926f9d540b0SHoward Hinnant    }
2927f9d540b0SHoward Hinnant    __n0_ = __n_ - __w_ % __n_;
2928f9d540b0SHoward Hinnant    if (__w0_ < _WDt - 1)
2929c003db1fSHoward Hinnant        __y1_ = (_Rp >> (__w0_ + 1)) << (__w0_ + 1);
2930f9d540b0SHoward Hinnant    else
2931f9d540b0SHoward Hinnant        __y1_ = 0;
2932f9d540b0SHoward Hinnant    __mask0_ = __w0_ > 0 ? _Engine_result_type(~0) >> (_EDt - __w0_) :
2933f9d540b0SHoward Hinnant                          _Engine_result_type(0);
2934f9d540b0SHoward Hinnant    __mask1_ = __w0_ < _EDt - 1 ?
2935f9d540b0SHoward Hinnant                               _Engine_result_type(~0) >> (_EDt - (__w0_ + 1)) :
2936f9d540b0SHoward Hinnant                               _Engine_result_type(~0);
29373e519524SHoward Hinnant}
29383e519524SHoward Hinnant
2939f9d540b0SHoward Hinnanttemplate<class _Engine, class _UIntType>
2940f9d540b0SHoward Hinnantinline
2941f9d540b0SHoward Hinnant_UIntType
294208bba64aSMarshall Clow__independent_bits_engine<_Engine, _UIntType>::__eval(false_type)
29433e519524SHoward Hinnant{
2944f9d540b0SHoward Hinnant    return static_cast<result_type>(__e_() & __mask0_);
29453e519524SHoward Hinnant}
29463e519524SHoward Hinnant
2947f9d540b0SHoward Hinnanttemplate<class _Engine, class _UIntType>
2948f9d540b0SHoward Hinnant_UIntType
294908bba64aSMarshall Clow__independent_bits_engine<_Engine, _UIntType>::__eval(true_type)
29503e519524SHoward Hinnant{
29515beb2c3aSMarshall Clow    const size_t _WRt = numeric_limits<result_type>::digits;
2952c003db1fSHoward Hinnant    result_type _Sp = 0;
2953f9d540b0SHoward Hinnant    for (size_t __k = 0; __k < __n0_; ++__k)
2954f9d540b0SHoward Hinnant    {
2955f9d540b0SHoward Hinnant        _Engine_result_type __u;
29563e519524SHoward Hinnant        do
2957f9d540b0SHoward Hinnant        {
2958f9d540b0SHoward Hinnant            __u = __e_() - _Engine::min();
2959f9d540b0SHoward Hinnant        } while (__u >= __y0_);
29605beb2c3aSMarshall Clow        if (__w0_ < _WRt)
2961c003db1fSHoward Hinnant            _Sp <<= __w0_;
2962f9d540b0SHoward Hinnant        else
2963c003db1fSHoward Hinnant            _Sp = 0;
2964c003db1fSHoward Hinnant        _Sp += __u & __mask0_;
2965f9d540b0SHoward Hinnant    }
2966f9d540b0SHoward Hinnant    for (size_t __k = __n0_; __k < __n_; ++__k)
2967f9d540b0SHoward Hinnant    {
2968f9d540b0SHoward Hinnant        _Engine_result_type __u;
2969f9d540b0SHoward Hinnant        do
2970f9d540b0SHoward Hinnant        {
2971f9d540b0SHoward Hinnant            __u = __e_() - _Engine::min();
2972f9d540b0SHoward Hinnant        } while (__u >= __y1_);
29735beb2c3aSMarshall Clow        if (__w0_ < _WRt - 1)
2974c003db1fSHoward Hinnant            _Sp <<= __w0_ + 1;
2975f9d540b0SHoward Hinnant        else
2976c003db1fSHoward Hinnant            _Sp = 0;
2977c003db1fSHoward Hinnant        _Sp += __u & __mask1_;
2978f9d540b0SHoward Hinnant    }
2979c003db1fSHoward Hinnant    return _Sp;
29803e519524SHoward Hinnant}
29813e519524SHoward Hinnant
2982f9d540b0SHoward Hinnant// uniform_int_distribution
29833e519524SHoward Hinnant
2984f9d540b0SHoward Hinnanttemplate<class _IntType = int>
2985f9d540b0SHoward Hinnantclass uniform_int_distribution
29863e519524SHoward Hinnant{
2987f9d540b0SHoward Hinnantpublic:
2988f9d540b0SHoward Hinnant    // types
2989f9d540b0SHoward Hinnant    typedef _IntType result_type;
2990f9d540b0SHoward Hinnant
2991f9d540b0SHoward Hinnant    class param_type
2992f9d540b0SHoward Hinnant    {
2993f9d540b0SHoward Hinnant        result_type __a_;
2994f9d540b0SHoward Hinnant        result_type __b_;
2995f9d540b0SHoward Hinnant    public:
2996f9d540b0SHoward Hinnant        typedef uniform_int_distribution distribution_type;
2997f9d540b0SHoward Hinnant
2998f9d540b0SHoward Hinnant        explicit param_type(result_type __a = 0,
2999f9d540b0SHoward Hinnant                            result_type __b = numeric_limits<result_type>::max())
3000f9d540b0SHoward Hinnant            : __a_(__a), __b_(__b) {}
3001f9d540b0SHoward Hinnant
3002f9d540b0SHoward Hinnant        result_type a() const {return __a_;}
3003f9d540b0SHoward Hinnant        result_type b() const {return __b_;}
3004f9d540b0SHoward Hinnant
3005f9d540b0SHoward Hinnant        friend bool operator==(const param_type& __x, const param_type& __y)
3006f9d540b0SHoward Hinnant            {return __x.__a_ == __y.__a_ && __x.__b_ == __y.__b_;}
3007f9d540b0SHoward Hinnant        friend bool operator!=(const param_type& __x, const param_type& __y)
3008f9d540b0SHoward Hinnant            {return !(__x == __y);}
30093e519524SHoward Hinnant    };
30103e519524SHoward Hinnant
3011f9d540b0SHoward Hinnantprivate:
3012f9d540b0SHoward Hinnant    param_type __p_;
30133e519524SHoward Hinnant
3014f9d540b0SHoward Hinnantpublic:
3015f9d540b0SHoward Hinnant    // constructors and reset functions
3016a11f8b1aSMarek Kurdej#ifndef _LIBCPP_CXX03_LANG
3017a11f8b1aSMarek Kurdej    uniform_int_distribution() : uniform_int_distribution(0) {}
3018a11f8b1aSMarek Kurdej    explicit uniform_int_distribution(
3019a11f8b1aSMarek Kurdej        result_type __a, result_type __b = numeric_limits<result_type>::max())
3020a11f8b1aSMarek Kurdej        : __p_(param_type(__a, __b)) {}
3021a11f8b1aSMarek Kurdej#else
3022a11f8b1aSMarek Kurdej    explicit uniform_int_distribution(
3023a11f8b1aSMarek Kurdej        result_type __a = 0,
3024f9d540b0SHoward Hinnant        result_type __b = numeric_limits<result_type>::max())
3025f9d540b0SHoward Hinnant        : __p_(param_type(__a, __b)) {}
3026a11f8b1aSMarek Kurdej#endif
3027f9d540b0SHoward Hinnant    explicit uniform_int_distribution(const param_type& __p) : __p_(__p) {}
3028f9d540b0SHoward Hinnant    void reset() {}
3029f9d540b0SHoward Hinnant
3030f9d540b0SHoward Hinnant    // generating functions
3031f9d540b0SHoward Hinnant    template<class _URNG> result_type operator()(_URNG& __g)
3032f9d540b0SHoward Hinnant        {return (*this)(__g, __p_);}
3033f9d540b0SHoward Hinnant    template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
3034f9d540b0SHoward Hinnant
3035f9d540b0SHoward Hinnant    // property functions
3036f9d540b0SHoward Hinnant    result_type a() const {return __p_.a();}
3037f9d540b0SHoward Hinnant    result_type b() const {return __p_.b();}
3038f9d540b0SHoward Hinnant
3039f9d540b0SHoward Hinnant    param_type param() const {return __p_;}
3040f9d540b0SHoward Hinnant    void param(const param_type& __p) {__p_ = __p;}
3041f9d540b0SHoward Hinnant
3042f9d540b0SHoward Hinnant    result_type min() const {return a();}
3043f9d540b0SHoward Hinnant    result_type max() const {return b();}
3044f9d540b0SHoward Hinnant
3045f9d540b0SHoward Hinnant    friend bool operator==(const uniform_int_distribution& __x,
3046f9d540b0SHoward Hinnant                           const uniform_int_distribution& __y)
3047f9d540b0SHoward Hinnant        {return __x.__p_ == __y.__p_;}
3048f9d540b0SHoward Hinnant    friend bool operator!=(const uniform_int_distribution& __x,
3049f9d540b0SHoward Hinnant                           const uniform_int_distribution& __y)
3050f9d540b0SHoward Hinnant            {return !(__x == __y);}
30513e519524SHoward Hinnant};
30523e519524SHoward Hinnant
3053f9d540b0SHoward Hinnanttemplate<class _IntType>
3054f9d540b0SHoward Hinnanttemplate<class _URNG>
3055f9d540b0SHoward Hinnanttypename uniform_int_distribution<_IntType>::result_type
3056f9d540b0SHoward Hinnantuniform_int_distribution<_IntType>::operator()(_URNG& __g, const param_type& __p)
30572dd53352SMarshall Clow_LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK
30583e519524SHoward Hinnant{
3059f9d540b0SHoward Hinnant    typedef typename conditional<sizeof(result_type) <= sizeof(uint32_t),
3060f9d540b0SHoward Hinnant                                            uint32_t, uint64_t>::type _UIntType;
30612dd53352SMarshall Clow    const _UIntType _Rp = _UIntType(__p.b()) - _UIntType(__p.a()) + _UIntType(1);
3062c003db1fSHoward Hinnant    if (_Rp == 1)
3063f9d540b0SHoward Hinnant        return __p.a();
3064f9d540b0SHoward Hinnant    const size_t _Dt = numeric_limits<_UIntType>::digits;
3065f9d540b0SHoward Hinnant    typedef __independent_bits_engine<_URNG, _UIntType> _Eng;
3066c003db1fSHoward Hinnant    if (_Rp == 0)
3067f9d540b0SHoward Hinnant        return static_cast<result_type>(_Eng(__g, _Dt)());
3068f3b851f0SMarshall Clow    size_t __w = _Dt - __libcpp_clz(_Rp) - 1;
3069d586f92cSArthur O'Dwyer    if ((_Rp & (numeric_limits<_UIntType>::max() >> (_Dt - __w))) != 0)
3070f9d540b0SHoward Hinnant        ++__w;
3071f9d540b0SHoward Hinnant    _Eng __e(__g, __w);
3072f9d540b0SHoward Hinnant    _UIntType __u;
3073f9d540b0SHoward Hinnant    do
30743e519524SHoward Hinnant    {
3075f9d540b0SHoward Hinnant        __u = __e();
3076c003db1fSHoward Hinnant    } while (__u >= _Rp);
3077f9d540b0SHoward Hinnant    return static_cast<result_type>(__u + __p.a());
30783e519524SHoward Hinnant}
3079f9d540b0SHoward Hinnant
308066f1ec46SEric Fiselier#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_RANDOM_SHUFFLE) \
308166f1ec46SEric Fiselier  || defined(_LIBCPP_BUILDING_LIBRARY)
3082f0544c20SHoward Hinnantclass _LIBCPP_TYPE_VIS __rs_default;
3083f9d540b0SHoward Hinnant
3084f0544c20SHoward Hinnant_LIBCPP_FUNC_VIS __rs_default __rs_get();
3085f9d540b0SHoward Hinnant
3086f0544c20SHoward Hinnantclass _LIBCPP_TYPE_VIS __rs_default
30873e519524SHoward Hinnant{
3088f9d540b0SHoward Hinnant    static unsigned __c_;
3089f9d540b0SHoward Hinnant
3090f9d540b0SHoward Hinnant    __rs_default();
3091f9d540b0SHoward Hinnantpublic:
3092b6e5f854SMarshall Clow    typedef uint_fast32_t result_type;
3093f9d540b0SHoward Hinnant
3094f9d540b0SHoward Hinnant    static const result_type _Min = 0;
3095f9d540b0SHoward Hinnant    static const result_type _Max = 0xFFFFFFFF;
3096f9d540b0SHoward Hinnant
3097f9d540b0SHoward Hinnant    __rs_default(const __rs_default&);
3098f9d540b0SHoward Hinnant    ~__rs_default();
3099f9d540b0SHoward Hinnant
3100f9d540b0SHoward Hinnant    result_type operator()();
3101f9d540b0SHoward Hinnant
3102788c9979SHoward Hinnant    static _LIBCPP_CONSTEXPR result_type min() {return _Min;}
3103788c9979SHoward Hinnant    static _LIBCPP_CONSTEXPR result_type max() {return _Max;}
3104f9d540b0SHoward Hinnant
3105f0544c20SHoward Hinnant    friend _LIBCPP_FUNC_VIS __rs_default __rs_get();
3106f9d540b0SHoward Hinnant};
3107f9d540b0SHoward Hinnant
3108f0544c20SHoward Hinnant_LIBCPP_FUNC_VIS __rs_default __rs_get();
31093e519524SHoward Hinnant
31103e519524SHoward Hinnanttemplate <class _RandomAccessIterator>
3111ea5cd3b4SLouis Dionne_LIBCPP_DEPRECATED_IN_CXX14 void
31123e519524SHoward Hinnantrandom_shuffle(_RandomAccessIterator __first, _RandomAccessIterator __last)
31133e519524SHoward Hinnant{
31143e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
3115c003db1fSHoward Hinnant    typedef uniform_int_distribution<ptrdiff_t> _Dp;
3116c003db1fSHoward Hinnant    typedef typename _Dp::param_type _Pp;
31173e519524SHoward Hinnant    difference_type __d = __last - __first;
31183e519524SHoward Hinnant    if (__d > 1)
31193e519524SHoward Hinnant    {
3120c003db1fSHoward Hinnant        _Dp __uid;
3121f9d540b0SHoward Hinnant        __rs_default __g = __rs_get();
31225a8525e0SMarshall Clow        for (--__last, (void) --__d; __first < __last; ++__first, (void) --__d)
3123007b26beSHoward Hinnant        {
3124c003db1fSHoward Hinnant            difference_type __i = __uid(__g, _Pp(0, __d));
3125007b26beSHoward Hinnant            if (__i != difference_type(0))
3126007b26beSHoward Hinnant                swap(*__first, *(__first + __i));
3127007b26beSHoward Hinnant        }
31283e519524SHoward Hinnant    }
31293e519524SHoward Hinnant}
31303e519524SHoward Hinnant
31313e519524SHoward Hinnanttemplate <class _RandomAccessIterator, class _RandomNumberGenerator>
3132ea5cd3b4SLouis Dionne_LIBCPP_DEPRECATED_IN_CXX14 void
31333e519524SHoward Hinnantrandom_shuffle(_RandomAccessIterator __first, _RandomAccessIterator __last,
3134ddda456aSEric Fiselier#ifndef _LIBCPP_CXX03_LANG
31353e519524SHoward Hinnant               _RandomNumberGenerator&& __rand)
31363e519524SHoward Hinnant#else
31373e519524SHoward Hinnant               _RandomNumberGenerator& __rand)
31383e519524SHoward Hinnant#endif
31393e519524SHoward Hinnant{
31403e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
31413e519524SHoward Hinnant    difference_type __d = __last - __first;
31423e519524SHoward Hinnant    if (__d > 1)
31433e519524SHoward Hinnant    {
31445a8525e0SMarshall Clow        for (--__last; __first < __last; ++__first, (void) --__d)
3145007b26beSHoward Hinnant        {
3146007b26beSHoward Hinnant            difference_type __i = __rand(__d);
3147e9cc5451SMarshall Clow            if (__i != difference_type(0))
3148007b26beSHoward Hinnant              swap(*__first, *(__first + __i));
3149007b26beSHoward Hinnant        }
31503e519524SHoward Hinnant    }
31513e519524SHoward Hinnant}
31520f37a410SMarshall Clow#endif
31533e519524SHoward Hinnant
3154e7154709SEric Fiseliertemplate <class _PopulationIterator, class _SampleIterator, class _Distance,
3155e7154709SEric Fiselier          class _UniformRandomNumberGenerator>
3156e7154709SEric Fiselier_LIBCPP_INLINE_VISIBILITY
3157e7154709SEric Fiselier_SampleIterator __sample(_PopulationIterator __first,
315842bfedd9SAlexander Richardson                         _PopulationIterator __last, _SampleIterator __output_iter,
3159e7154709SEric Fiselier                         _Distance __n,
3160e7154709SEric Fiselier                         _UniformRandomNumberGenerator & __g,
3161e7154709SEric Fiselier                         input_iterator_tag) {
3162e7154709SEric Fiselier
3163e7154709SEric Fiselier  _Distance __k = 0;
3164e7154709SEric Fiselier  for (; __first != __last && __k < __n; ++__first, (void) ++__k)
316542bfedd9SAlexander Richardson    __output_iter[__k] = *__first;
3166e7154709SEric Fiselier  _Distance __sz = __k;
3167e7154709SEric Fiselier  for (; __first != __last; ++__first, (void) ++__k) {
3168e7154709SEric Fiselier    _Distance __r = _VSTD::uniform_int_distribution<_Distance>(0, __k)(__g);
3169e7154709SEric Fiselier    if (__r < __sz)
317042bfedd9SAlexander Richardson      __output_iter[__r] = *__first;
3171e7154709SEric Fiselier  }
317242bfedd9SAlexander Richardson  return __output_iter + _VSTD::min(__n, __k);
3173e7154709SEric Fiselier}
3174e7154709SEric Fiselier
3175e7154709SEric Fiseliertemplate <class _PopulationIterator, class _SampleIterator, class _Distance,
3176e7154709SEric Fiselier          class _UniformRandomNumberGenerator>
3177e7154709SEric Fiselier_LIBCPP_INLINE_VISIBILITY
3178e7154709SEric Fiselier_SampleIterator __sample(_PopulationIterator __first,
317942bfedd9SAlexander Richardson                         _PopulationIterator __last, _SampleIterator __output_iter,
3180e7154709SEric Fiselier                         _Distance __n,
3181e7154709SEric Fiselier                         _UniformRandomNumberGenerator& __g,
3182e7154709SEric Fiselier                         forward_iterator_tag) {
3183e7154709SEric Fiselier  _Distance __unsampled_sz = _VSTD::distance(__first, __last);
3184e7154709SEric Fiselier  for (__n = _VSTD::min(__n, __unsampled_sz); __n != 0; ++__first) {
3185e7154709SEric Fiselier    _Distance __r =
3186e7154709SEric Fiselier        _VSTD::uniform_int_distribution<_Distance>(0, --__unsampled_sz)(__g);
3187e7154709SEric Fiselier    if (__r < __n) {
318842bfedd9SAlexander Richardson      *__output_iter++ = *__first;
3189e7154709SEric Fiselier      --__n;
3190e7154709SEric Fiselier    }
3191e7154709SEric Fiselier  }
319242bfedd9SAlexander Richardson  return __output_iter;
3193e7154709SEric Fiselier}
3194e7154709SEric Fiselier
3195e7154709SEric Fiseliertemplate <class _PopulationIterator, class _SampleIterator, class _Distance,
3196e7154709SEric Fiselier          class _UniformRandomNumberGenerator>
3197e7154709SEric Fiselier_LIBCPP_INLINE_VISIBILITY
3198e7154709SEric Fiselier_SampleIterator __sample(_PopulationIterator __first,
319942bfedd9SAlexander Richardson                         _PopulationIterator __last, _SampleIterator __output_iter,
3200e7154709SEric Fiselier                         _Distance __n, _UniformRandomNumberGenerator& __g) {
3201e7154709SEric Fiselier  typedef typename iterator_traits<_PopulationIterator>::iterator_category
3202e7154709SEric Fiselier        _PopCategory;
3203e7154709SEric Fiselier  typedef typename iterator_traits<_PopulationIterator>::difference_type
3204e7154709SEric Fiselier        _Difference;
3205f82dba01SEric Fiselier  static_assert(__is_cpp17_forward_iterator<_PopulationIterator>::value ||
3206f82dba01SEric Fiselier                __is_cpp17_random_access_iterator<_SampleIterator>::value,
3207e7154709SEric Fiselier                "SampleIterator must meet the requirements of RandomAccessIterator");
3208e7154709SEric Fiselier  typedef typename common_type<_Distance, _Difference>::type _CommonType;
3209e7154709SEric Fiselier  _LIBCPP_ASSERT(__n >= 0, "N must be a positive number.");
3210e7154709SEric Fiselier  return _VSTD::__sample(
321142bfedd9SAlexander Richardson      __first, __last, __output_iter, _CommonType(__n),
3212e7154709SEric Fiselier      __g, _PopCategory());
3213e7154709SEric Fiselier}
3214e7154709SEric Fiselier
3215e7154709SEric Fiselier#if _LIBCPP_STD_VER > 14
3216e7154709SEric Fiseliertemplate <class _PopulationIterator, class _SampleIterator, class _Distance,
3217e7154709SEric Fiselier          class _UniformRandomNumberGenerator>
3218e7154709SEric Fiselierinline _LIBCPP_INLINE_VISIBILITY
3219e7154709SEric Fiselier_SampleIterator sample(_PopulationIterator __first,
322042bfedd9SAlexander Richardson                       _PopulationIterator __last, _SampleIterator __output_iter,
3221e7154709SEric Fiselier                       _Distance __n, _UniformRandomNumberGenerator&& __g) {
322242bfedd9SAlexander Richardson    return _VSTD::__sample(__first, __last, __output_iter, __n, __g);
3223e7154709SEric Fiselier}
3224e7154709SEric Fiselier#endif // _LIBCPP_STD_VER > 14
3225e7154709SEric Fiselier
3226f9d540b0SHoward Hinnanttemplate<class _RandomAccessIterator, class _UniformRandomNumberGenerator>
3227f9d540b0SHoward Hinnant    void shuffle(_RandomAccessIterator __first, _RandomAccessIterator __last,
3228fb340102SHoward Hinnant                 _UniformRandomNumberGenerator&& __g)
3229f9d540b0SHoward Hinnant{
3230f9d540b0SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
3231c003db1fSHoward Hinnant    typedef uniform_int_distribution<ptrdiff_t> _Dp;
3232c003db1fSHoward Hinnant    typedef typename _Dp::param_type _Pp;
3233f9d540b0SHoward Hinnant    difference_type __d = __last - __first;
3234f9d540b0SHoward Hinnant    if (__d > 1)
3235f9d540b0SHoward Hinnant    {
3236c003db1fSHoward Hinnant        _Dp __uid;
32377fa68653SMarshall Clow        for (--__last, (void) --__d; __first < __last; ++__first, (void) --__d)
3238007b26beSHoward Hinnant        {
3239c003db1fSHoward Hinnant            difference_type __i = __uid(__g, _Pp(0, __d));
3240007b26beSHoward Hinnant            if (__i != difference_type(0))
3241007b26beSHoward Hinnant                swap(*__first, *(__first + __i));
3242007b26beSHoward Hinnant        }
3243f9d540b0SHoward Hinnant    }
3244f9d540b0SHoward Hinnant}
3245f9d540b0SHoward Hinnant
32463fbd3eafSArthur O'Dwyer#if _LIBCPP_STD_VER > 17
32473fbd3eafSArthur O'Dwyer
32483fbd3eafSArthur O'Dwyer// shift_left, shift_right
32493fbd3eafSArthur O'Dwyer
32503fbd3eafSArthur O'Dwyertemplate <class _ForwardIterator>
32513fbd3eafSArthur O'Dwyerinline _LIBCPP_INLINE_VISIBILITY constexpr
32523fbd3eafSArthur O'Dwyer_ForwardIterator
32533fbd3eafSArthur O'Dwyershift_left(_ForwardIterator __first, _ForwardIterator __last,
32543fbd3eafSArthur O'Dwyer           typename iterator_traits<_ForwardIterator>::difference_type __n)
32553fbd3eafSArthur O'Dwyer{
32563fbd3eafSArthur O'Dwyer    if (__n == 0) {
32573fbd3eafSArthur O'Dwyer        return __last;
32583fbd3eafSArthur O'Dwyer    }
32593fbd3eafSArthur O'Dwyer
32603fbd3eafSArthur O'Dwyer    _ForwardIterator __m = __first;
32613fbd3eafSArthur O'Dwyer    if constexpr (__is_cpp17_random_access_iterator<_ForwardIterator>::value) {
32623fbd3eafSArthur O'Dwyer        if (__n >= __last - __first) {
32633fbd3eafSArthur O'Dwyer            return __first;
32643fbd3eafSArthur O'Dwyer        }
32653fbd3eafSArthur O'Dwyer        __m += __n;
32663fbd3eafSArthur O'Dwyer    } else {
32673fbd3eafSArthur O'Dwyer        for (; __n > 0; --__n) {
32683fbd3eafSArthur O'Dwyer            if (__m == __last) {
32693fbd3eafSArthur O'Dwyer                return __first;
32703fbd3eafSArthur O'Dwyer            }
32713fbd3eafSArthur O'Dwyer            ++__m;
32723fbd3eafSArthur O'Dwyer        }
32733fbd3eafSArthur O'Dwyer    }
32743fbd3eafSArthur O'Dwyer    return _VSTD::move(__m, __last, __first);
32753fbd3eafSArthur O'Dwyer}
32763fbd3eafSArthur O'Dwyer
32773fbd3eafSArthur O'Dwyertemplate <class _ForwardIterator>
32783fbd3eafSArthur O'Dwyerinline _LIBCPP_INLINE_VISIBILITY constexpr
32793fbd3eafSArthur O'Dwyer_ForwardIterator
32803fbd3eafSArthur O'Dwyershift_right(_ForwardIterator __first, _ForwardIterator __last,
32813fbd3eafSArthur O'Dwyer            typename iterator_traits<_ForwardIterator>::difference_type __n)
32823fbd3eafSArthur O'Dwyer{
32833fbd3eafSArthur O'Dwyer    if (__n == 0) {
32843fbd3eafSArthur O'Dwyer        return __first;
32853fbd3eafSArthur O'Dwyer    }
32863fbd3eafSArthur O'Dwyer
32873fbd3eafSArthur O'Dwyer    if constexpr (__is_cpp17_random_access_iterator<_ForwardIterator>::value) {
32883fbd3eafSArthur O'Dwyer        decltype(__n) __d = __last - __first;
32893fbd3eafSArthur O'Dwyer        if (__n >= __d) {
32903fbd3eafSArthur O'Dwyer            return __last;
32913fbd3eafSArthur O'Dwyer        }
32923fbd3eafSArthur O'Dwyer        _ForwardIterator __m = __first + (__d - __n);
32933fbd3eafSArthur O'Dwyer        return _VSTD::move_backward(__first, __m, __last);
32943fbd3eafSArthur O'Dwyer    } else if constexpr (__is_cpp17_bidirectional_iterator<_ForwardIterator>::value) {
32953fbd3eafSArthur O'Dwyer        _ForwardIterator __m = __last;
32963fbd3eafSArthur O'Dwyer        for (; __n > 0; --__n) {
32973fbd3eafSArthur O'Dwyer            if (__m == __first) {
32983fbd3eafSArthur O'Dwyer                return __last;
32993fbd3eafSArthur O'Dwyer            }
33003fbd3eafSArthur O'Dwyer            --__m;
33013fbd3eafSArthur O'Dwyer        }
33023fbd3eafSArthur O'Dwyer        return _VSTD::move_backward(__first, __m, __last);
33033fbd3eafSArthur O'Dwyer    } else {
33043fbd3eafSArthur O'Dwyer        _ForwardIterator __ret = __first;
33053fbd3eafSArthur O'Dwyer        for (; __n > 0; --__n) {
33063fbd3eafSArthur O'Dwyer            if (__ret == __last) {
33073fbd3eafSArthur O'Dwyer                return __last;
33083fbd3eafSArthur O'Dwyer            }
33093fbd3eafSArthur O'Dwyer            ++__ret;
33103fbd3eafSArthur O'Dwyer        }
33113fbd3eafSArthur O'Dwyer
33123fbd3eafSArthur O'Dwyer        // We have an __n-element scratch space from __first to __ret.
33133fbd3eafSArthur O'Dwyer        // Slide an __n-element window [__trail, __lead) from left to right.
33143fbd3eafSArthur O'Dwyer        // We're essentially doing swap_ranges(__first, __ret, __trail, __lead)
33153fbd3eafSArthur O'Dwyer        // over and over; but once __lead reaches __last we needn't bother
33163fbd3eafSArthur O'Dwyer        // to save the values of elements [__trail, __last).
33173fbd3eafSArthur O'Dwyer
33183fbd3eafSArthur O'Dwyer        auto __trail = __first;
33193fbd3eafSArthur O'Dwyer        auto __lead = __ret;
33203fbd3eafSArthur O'Dwyer        while (__trail != __ret) {
33213fbd3eafSArthur O'Dwyer            if (__lead == __last) {
33223fbd3eafSArthur O'Dwyer                _VSTD::move(__first, __trail, __ret);
33233fbd3eafSArthur O'Dwyer                return __ret;
33243fbd3eafSArthur O'Dwyer            }
33253fbd3eafSArthur O'Dwyer            ++__trail;
33263fbd3eafSArthur O'Dwyer            ++__lead;
33273fbd3eafSArthur O'Dwyer        }
33283fbd3eafSArthur O'Dwyer
33293fbd3eafSArthur O'Dwyer        _ForwardIterator __mid = __first;
33303fbd3eafSArthur O'Dwyer        while (true) {
33313fbd3eafSArthur O'Dwyer            if (__lead == __last) {
33323fbd3eafSArthur O'Dwyer                __trail = _VSTD::move(__mid, __ret, __trail);
33333fbd3eafSArthur O'Dwyer                _VSTD::move(__first, __mid, __trail);
33343fbd3eafSArthur O'Dwyer                return __ret;
33353fbd3eafSArthur O'Dwyer            }
33363fbd3eafSArthur O'Dwyer            swap(*__mid, *__trail);
33373fbd3eafSArthur O'Dwyer            ++__mid;
33383fbd3eafSArthur O'Dwyer            ++__trail;
33393fbd3eafSArthur O'Dwyer            ++__lead;
33403fbd3eafSArthur O'Dwyer            if (__mid == __ret) {
33413fbd3eafSArthur O'Dwyer                __mid = __first;
33423fbd3eafSArthur O'Dwyer            }
33433fbd3eafSArthur O'Dwyer        }
33443fbd3eafSArthur O'Dwyer    }
33453fbd3eafSArthur O'Dwyer}
33463fbd3eafSArthur O'Dwyer
33473fbd3eafSArthur O'Dwyer#endif // _LIBCPP_STD_VER > 17
33483fbd3eafSArthur O'Dwyer
33493fbd3eafSArthur O'Dwyer// is_partitioned
33503fbd3eafSArthur O'Dwyer
33513e519524SHoward Hinnanttemplate <class _InputIterator, class _Predicate>
33521362d7efSNico Weber_LIBCPP_NODISCARD_EXT _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
33533e519524SHoward Hinnantis_partitioned(_InputIterator __first, _InputIterator __last, _Predicate __pred)
33543e519524SHoward Hinnant{
33553e519524SHoward Hinnant    for (; __first != __last; ++__first)
33563e519524SHoward Hinnant        if (!__pred(*__first))
33573e519524SHoward Hinnant            break;
3358b9595b79SMarshall Clow    if ( __first == __last )
3359b9595b79SMarshall Clow        return true;
3360b9595b79SMarshall Clow    ++__first;
33613e519524SHoward Hinnant    for (; __first != __last; ++__first)
33623e519524SHoward Hinnant        if (__pred(*__first))
33633e519524SHoward Hinnant            return false;
33643e519524SHoward Hinnant    return true;
33653e519524SHoward Hinnant}
33663e519524SHoward Hinnant
33673e519524SHoward Hinnant// partition
33683e519524SHoward Hinnant
33693e519524SHoward Hinnanttemplate <class _Predicate, class _ForwardIterator>
3370f851db3dSArthur O'Dwyer_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
33713e519524SHoward Hinnant__partition(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred, forward_iterator_tag)
33723e519524SHoward Hinnant{
33733e519524SHoward Hinnant    while (true)
33743e519524SHoward Hinnant    {
33753e519524SHoward Hinnant        if (__first == __last)
33763e519524SHoward Hinnant            return __first;
33773e519524SHoward Hinnant        if (!__pred(*__first))
33783e519524SHoward Hinnant            break;
33793e519524SHoward Hinnant        ++__first;
33803e519524SHoward Hinnant    }
33813e519524SHoward Hinnant    for (_ForwardIterator __p = __first; ++__p != __last;)
33823e519524SHoward Hinnant    {
33833e519524SHoward Hinnant        if (__pred(*__p))
33843e519524SHoward Hinnant        {
33853e519524SHoward Hinnant            swap(*__first, *__p);
33863e519524SHoward Hinnant            ++__first;
33873e519524SHoward Hinnant        }
33883e519524SHoward Hinnant    }
33893e519524SHoward Hinnant    return __first;
33903e519524SHoward Hinnant}
33913e519524SHoward Hinnant
33923e519524SHoward Hinnanttemplate <class _Predicate, class _BidirectionalIterator>
3393f851db3dSArthur O'Dwyer_LIBCPP_CONSTEXPR_AFTER_CXX17 _BidirectionalIterator
33943e519524SHoward Hinnant__partition(_BidirectionalIterator __first, _BidirectionalIterator __last, _Predicate __pred,
33953e519524SHoward Hinnant            bidirectional_iterator_tag)
33963e519524SHoward Hinnant{
33973e519524SHoward Hinnant    while (true)
33983e519524SHoward Hinnant    {
33993e519524SHoward Hinnant        while (true)
34003e519524SHoward Hinnant        {
34013e519524SHoward Hinnant            if (__first == __last)
34023e519524SHoward Hinnant                return __first;
34033e519524SHoward Hinnant            if (!__pred(*__first))
34043e519524SHoward Hinnant                break;
34053e519524SHoward Hinnant            ++__first;
34063e519524SHoward Hinnant        }
34073e519524SHoward Hinnant        do
34083e519524SHoward Hinnant        {
34093e519524SHoward Hinnant            if (__first == --__last)
34103e519524SHoward Hinnant                return __first;
34113e519524SHoward Hinnant        } while (!__pred(*__last));
34123e519524SHoward Hinnant        swap(*__first, *__last);
34133e519524SHoward Hinnant        ++__first;
34143e519524SHoward Hinnant    }
34153e519524SHoward Hinnant}
34163e519524SHoward Hinnant
34173e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Predicate>
3418f851db3dSArthur O'Dwyerinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
34193e519524SHoward Hinnant_ForwardIterator
34203e519524SHoward Hinnantpartition(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred)
34213e519524SHoward Hinnant{
3422ce48a113SHoward Hinnant    return _VSTD::__partition<typename add_lvalue_reference<_Predicate>::type>
34233e519524SHoward Hinnant                            (__first, __last, __pred, typename iterator_traits<_ForwardIterator>::iterator_category());
34243e519524SHoward Hinnant}
34253e519524SHoward Hinnant
34263e519524SHoward Hinnant// partition_copy
34273e519524SHoward Hinnant
34283e519524SHoward Hinnanttemplate <class _InputIterator, class _OutputIterator1,
34293e519524SHoward Hinnant          class _OutputIterator2, class _Predicate>
34301b9a4ffdSMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 pair<_OutputIterator1, _OutputIterator2>
34313e519524SHoward Hinnantpartition_copy(_InputIterator __first, _InputIterator __last,
34323e519524SHoward Hinnant               _OutputIterator1 __out_true, _OutputIterator2 __out_false,
34333e519524SHoward Hinnant               _Predicate __pred)
34343e519524SHoward Hinnant{
34353e519524SHoward Hinnant    for (; __first != __last; ++__first)
34363e519524SHoward Hinnant    {
34373e519524SHoward Hinnant        if (__pred(*__first))
34383e519524SHoward Hinnant        {
34393e519524SHoward Hinnant            *__out_true = *__first;
34403e519524SHoward Hinnant            ++__out_true;
34413e519524SHoward Hinnant        }
34423e519524SHoward Hinnant        else
34433e519524SHoward Hinnant        {
34443e519524SHoward Hinnant            *__out_false = *__first;
34453e519524SHoward Hinnant            ++__out_false;
34463e519524SHoward Hinnant        }
34473e519524SHoward Hinnant    }
34483e519524SHoward Hinnant    return pair<_OutputIterator1, _OutputIterator2>(__out_true, __out_false);
34493e519524SHoward Hinnant}
34503e519524SHoward Hinnant
34513e519524SHoward Hinnant// partition_point
34523e519524SHoward Hinnant
34533e519524SHoward Hinnanttemplate<class _ForwardIterator, class _Predicate>
3454674f9128SMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
34553e519524SHoward Hinnantpartition_point(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred)
34563e519524SHoward Hinnant{
34573e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator>::difference_type difference_type;
3458ce48a113SHoward Hinnant    difference_type __len = _VSTD::distance(__first, __last);
34593e519524SHoward Hinnant    while (__len != 0)
34603e519524SHoward Hinnant    {
346104695a75SLouis Dionne        difference_type __l2 = _VSTD::__half_positive(__len);
34623e519524SHoward Hinnant        _ForwardIterator __m = __first;
3463ce48a113SHoward Hinnant        _VSTD::advance(__m, __l2);
34643e519524SHoward Hinnant        if (__pred(*__m))
34653e519524SHoward Hinnant        {
34663e519524SHoward Hinnant            __first = ++__m;
34673e519524SHoward Hinnant            __len -= __l2 + 1;
34683e519524SHoward Hinnant        }
34693e519524SHoward Hinnant        else
34703e519524SHoward Hinnant            __len = __l2;
34713e519524SHoward Hinnant    }
34723e519524SHoward Hinnant    return __first;
34733e519524SHoward Hinnant}
34743e519524SHoward Hinnant
34753e519524SHoward Hinnant// stable_partition
34763e519524SHoward Hinnant
34773e519524SHoward Hinnanttemplate <class _Predicate, class _ForwardIterator, class _Distance, class _Pair>
34783e519524SHoward Hinnant_ForwardIterator
34793e519524SHoward Hinnant__stable_partition(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred,
34803e519524SHoward Hinnant                   _Distance __len, _Pair __p, forward_iterator_tag __fit)
34813e519524SHoward Hinnant{
34823e519524SHoward Hinnant    // *__first is known to be false
34833e519524SHoward Hinnant    // __len >= 1
34843e519524SHoward Hinnant    if (__len == 1)
34853e519524SHoward Hinnant        return __first;
34863e519524SHoward Hinnant    if (__len == 2)
34873e519524SHoward Hinnant    {
34883e519524SHoward Hinnant        _ForwardIterator __m = __first;
34893e519524SHoward Hinnant        if (__pred(*++__m))
34903e519524SHoward Hinnant        {
34913e519524SHoward Hinnant            swap(*__first, *__m);
34923e519524SHoward Hinnant            return __m;
34933e519524SHoward Hinnant        }
34943e519524SHoward Hinnant        return __first;
34953e519524SHoward Hinnant    }
34963e519524SHoward Hinnant    if (__len <= __p.second)
34973e519524SHoward Hinnant    {   // The buffer is big enough to use
34983e519524SHoward Hinnant        typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
34993e519524SHoward Hinnant        __destruct_n __d(0);
35003e519524SHoward Hinnant        unique_ptr<value_type, __destruct_n&> __h(__p.first, __d);
35013e519524SHoward Hinnant        // Move the falses into the temporary buffer, and the trues to the front of the line
35023e519524SHoward Hinnant        // Update __first to always point to the end of the trues
35033e519524SHoward Hinnant        value_type* __t = __p.first;
3504be4c657bSArthur O'Dwyer        ::new ((void*)__t) value_type(_VSTD::move(*__first));
3505527a7fdfSBruce Mitchener        __d.template __incr<value_type>();
35063e519524SHoward Hinnant        ++__t;
35073e519524SHoward Hinnant        _ForwardIterator __i = __first;
35083e519524SHoward Hinnant        while (++__i != __last)
35093e519524SHoward Hinnant        {
35103e519524SHoward Hinnant            if (__pred(*__i))
35113e519524SHoward Hinnant            {
3512ce48a113SHoward Hinnant                *__first = _VSTD::move(*__i);
35133e519524SHoward Hinnant                ++__first;
35143e519524SHoward Hinnant            }
35153e519524SHoward Hinnant            else
35163e519524SHoward Hinnant            {
3517be4c657bSArthur O'Dwyer                ::new ((void*)__t) value_type(_VSTD::move(*__i));
3518527a7fdfSBruce Mitchener                __d.template __incr<value_type>();
35193e519524SHoward Hinnant                ++__t;
35203e519524SHoward Hinnant            }
35213e519524SHoward Hinnant        }
35223e519524SHoward Hinnant        // All trues now at start of range, all falses in buffer
35233e519524SHoward Hinnant        // Move falses back into range, but don't mess up __first which points to first false
35243e519524SHoward Hinnant        __i = __first;
35257fa68653SMarshall Clow        for (value_type* __t2 = __p.first; __t2 < __t; ++__t2, (void) ++__i)
3526ce48a113SHoward Hinnant            *__i = _VSTD::move(*__t2);
35273e519524SHoward Hinnant        // __h destructs moved-from values out of the temp buffer, but doesn't deallocate buffer
35283e519524SHoward Hinnant        return __first;
35293e519524SHoward Hinnant    }
35303e519524SHoward Hinnant    // Else not enough buffer, do in place
35313e519524SHoward Hinnant    // __len >= 3
35323e519524SHoward Hinnant    _ForwardIterator __m = __first;
35333e519524SHoward Hinnant    _Distance __len2 = __len / 2;  // __len2 >= 2
3534ce48a113SHoward Hinnant    _VSTD::advance(__m, __len2);
35353e519524SHoward Hinnant    // recurse on [__first, __m), *__first know to be false
35363e519524SHoward Hinnant    // F?????????????????
35373e519524SHoward Hinnant    // f       m         l
35383e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Predicate>::type _PredRef;
35391968804aSArthur O'Dwyer    _ForwardIterator __first_false = _VSTD::__stable_partition<_PredRef>(__first, __m, __pred, __len2, __p, __fit);
35403e519524SHoward Hinnant    // TTTFFFFF??????????
35413e519524SHoward Hinnant    // f  ff   m         l
35423e519524SHoward Hinnant    // recurse on [__m, __last], except increase __m until *(__m) is false, *__last know to be true
35433e519524SHoward Hinnant    _ForwardIterator __m1 = __m;
35443e519524SHoward Hinnant    _ForwardIterator __second_false = __last;
35453e519524SHoward Hinnant    _Distance __len_half = __len - __len2;
35463e519524SHoward Hinnant    while (__pred(*__m1))
35473e519524SHoward Hinnant    {
35483e519524SHoward Hinnant        if (++__m1 == __last)
35493e519524SHoward Hinnant            goto __second_half_done;
35503e519524SHoward Hinnant        --__len_half;
35513e519524SHoward Hinnant    }
35523e519524SHoward Hinnant    // TTTFFFFFTTTF??????
35533e519524SHoward Hinnant    // f  ff   m  m1     l
35541968804aSArthur O'Dwyer    __second_false = _VSTD::__stable_partition<_PredRef>(__m1, __last, __pred, __len_half, __p, __fit);
35553e519524SHoward Hinnant__second_half_done:
35563e519524SHoward Hinnant    // TTTFFFFFTTTTTFFFFF
35573e519524SHoward Hinnant    // f  ff   m    sf   l
3558ce48a113SHoward Hinnant    return _VSTD::rotate(__first_false, __m, __second_false);
35593e519524SHoward Hinnant    // TTTTTTTTFFFFFFFFFF
35603e519524SHoward Hinnant    //         |
35613e519524SHoward Hinnant}
35623e519524SHoward Hinnant
35633e519524SHoward Hinnantstruct __return_temporary_buffer
35643e519524SHoward Hinnant{
35653e519524SHoward Hinnant    template <class _Tp>
3566ce48a113SHoward Hinnant    _LIBCPP_INLINE_VISIBILITY void operator()(_Tp* __p) const {_VSTD::return_temporary_buffer(__p);}
35673e519524SHoward Hinnant};
35683e519524SHoward Hinnant
35693e519524SHoward Hinnanttemplate <class _Predicate, class _ForwardIterator>
35703e519524SHoward Hinnant_ForwardIterator
35713e519524SHoward Hinnant__stable_partition(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred,
35723e519524SHoward Hinnant                   forward_iterator_tag)
35733e519524SHoward Hinnant{
35743e519524SHoward Hinnant    const unsigned __alloc_limit = 3;  // might want to make this a function of trivial assignment
35753e519524SHoward Hinnant    // Either prove all true and return __first or point to first false
35763e519524SHoward Hinnant    while (true)
35773e519524SHoward Hinnant    {
35783e519524SHoward Hinnant        if (__first == __last)
35793e519524SHoward Hinnant            return __first;
35803e519524SHoward Hinnant        if (!__pred(*__first))
35813e519524SHoward Hinnant            break;
35823e519524SHoward Hinnant        ++__first;
35833e519524SHoward Hinnant    }
35843e519524SHoward Hinnant    // We now have a reduced range [__first, __last)
35853e519524SHoward Hinnant    // *__first is known to be false
35863e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator>::difference_type difference_type;
35873e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
3588ce48a113SHoward Hinnant    difference_type __len = _VSTD::distance(__first, __last);
35893e519524SHoward Hinnant    pair<value_type*, ptrdiff_t> __p(0, 0);
35903e519524SHoward Hinnant    unique_ptr<value_type, __return_temporary_buffer> __h;
35913e519524SHoward Hinnant    if (__len >= __alloc_limit)
35923e519524SHoward Hinnant    {
3593ce48a113SHoward Hinnant        __p = _VSTD::get_temporary_buffer<value_type>(__len);
35943e519524SHoward Hinnant        __h.reset(__p.first);
35953e519524SHoward Hinnant    }
35961968804aSArthur O'Dwyer    return _VSTD::__stable_partition<typename add_lvalue_reference<_Predicate>::type>
35973e519524SHoward Hinnant                             (__first, __last, __pred, __len, __p, forward_iterator_tag());
35983e519524SHoward Hinnant}
35993e519524SHoward Hinnant
36003e519524SHoward Hinnanttemplate <class _Predicate, class _BidirectionalIterator, class _Distance, class _Pair>
36013e519524SHoward Hinnant_BidirectionalIterator
36023e519524SHoward Hinnant__stable_partition(_BidirectionalIterator __first, _BidirectionalIterator __last, _Predicate __pred,
36033e519524SHoward Hinnant                   _Distance __len, _Pair __p, bidirectional_iterator_tag __bit)
36043e519524SHoward Hinnant{
36053e519524SHoward Hinnant    // *__first is known to be false
36063e519524SHoward Hinnant    // *__last is known to be true
36073e519524SHoward Hinnant    // __len >= 2
36083e519524SHoward Hinnant    if (__len == 2)
36093e519524SHoward Hinnant    {
36103e519524SHoward Hinnant        swap(*__first, *__last);
36113e519524SHoward Hinnant        return __last;
36123e519524SHoward Hinnant    }
36133e519524SHoward Hinnant    if (__len == 3)
36143e519524SHoward Hinnant    {
36153e519524SHoward Hinnant        _BidirectionalIterator __m = __first;
36163e519524SHoward Hinnant        if (__pred(*++__m))
36173e519524SHoward Hinnant        {
36183e519524SHoward Hinnant            swap(*__first, *__m);
36193e519524SHoward Hinnant            swap(*__m, *__last);
36203e519524SHoward Hinnant            return __last;
36213e519524SHoward Hinnant        }
36223e519524SHoward Hinnant        swap(*__m, *__last);
36233e519524SHoward Hinnant        swap(*__first, *__m);
36243e519524SHoward Hinnant        return __m;
36253e519524SHoward Hinnant    }
36263e519524SHoward Hinnant    if (__len <= __p.second)
36273e519524SHoward Hinnant    {   // The buffer is big enough to use
36283e519524SHoward Hinnant        typedef typename iterator_traits<_BidirectionalIterator>::value_type value_type;
36293e519524SHoward Hinnant        __destruct_n __d(0);
36303e519524SHoward Hinnant        unique_ptr<value_type, __destruct_n&> __h(__p.first, __d);
36313e519524SHoward Hinnant        // Move the falses into the temporary buffer, and the trues to the front of the line
36323e519524SHoward Hinnant        // Update __first to always point to the end of the trues
36333e519524SHoward Hinnant        value_type* __t = __p.first;
3634be4c657bSArthur O'Dwyer        ::new ((void*)__t) value_type(_VSTD::move(*__first));
3635527a7fdfSBruce Mitchener        __d.template __incr<value_type>();
36363e519524SHoward Hinnant        ++__t;
36373e519524SHoward Hinnant        _BidirectionalIterator __i = __first;
36383e519524SHoward Hinnant        while (++__i != __last)
36393e519524SHoward Hinnant        {
36403e519524SHoward Hinnant            if (__pred(*__i))
36413e519524SHoward Hinnant            {
3642ce48a113SHoward Hinnant                *__first = _VSTD::move(*__i);
36433e519524SHoward Hinnant                ++__first;
36443e519524SHoward Hinnant            }
36453e519524SHoward Hinnant            else
36463e519524SHoward Hinnant            {
3647be4c657bSArthur O'Dwyer                ::new ((void*)__t) value_type(_VSTD::move(*__i));
3648527a7fdfSBruce Mitchener                __d.template __incr<value_type>();
36493e519524SHoward Hinnant                ++__t;
36503e519524SHoward Hinnant            }
36513e519524SHoward Hinnant        }
36523e519524SHoward Hinnant        // move *__last, known to be true
3653ce48a113SHoward Hinnant        *__first = _VSTD::move(*__i);
36543e519524SHoward Hinnant        __i = ++__first;
36553e519524SHoward Hinnant        // All trues now at start of range, all falses in buffer
36563e519524SHoward Hinnant        // Move falses back into range, but don't mess up __first which points to first false
36577fa68653SMarshall Clow        for (value_type* __t2 = __p.first; __t2 < __t; ++__t2, (void) ++__i)
3658ce48a113SHoward Hinnant            *__i = _VSTD::move(*__t2);
36593e519524SHoward Hinnant        // __h destructs moved-from values out of the temp buffer, but doesn't deallocate buffer
36603e519524SHoward Hinnant        return __first;
36613e519524SHoward Hinnant    }
36623e519524SHoward Hinnant    // Else not enough buffer, do in place
36633e519524SHoward Hinnant    // __len >= 4
36643e519524SHoward Hinnant    _BidirectionalIterator __m = __first;
36653e519524SHoward Hinnant    _Distance __len2 = __len / 2;  // __len2 >= 2
3666ce48a113SHoward Hinnant    _VSTD::advance(__m, __len2);
36673e519524SHoward Hinnant    // recurse on [__first, __m-1], except reduce __m-1 until *(__m-1) is true, *__first know to be false
36683e519524SHoward Hinnant    // F????????????????T
36693e519524SHoward Hinnant    // f       m        l
36703e519524SHoward Hinnant    _BidirectionalIterator __m1 = __m;
36713e519524SHoward Hinnant    _BidirectionalIterator __first_false = __first;
36723e519524SHoward Hinnant    _Distance __len_half = __len2;
36733e519524SHoward Hinnant    while (!__pred(*--__m1))
36743e519524SHoward Hinnant    {
36753e519524SHoward Hinnant        if (__m1 == __first)
36763e519524SHoward Hinnant            goto __first_half_done;
36773e519524SHoward Hinnant        --__len_half;
36783e519524SHoward Hinnant    }
36793e519524SHoward Hinnant    // F???TFFF?????????T
36803e519524SHoward Hinnant    // f   m1  m        l
36813e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Predicate>::type _PredRef;
36821968804aSArthur O'Dwyer    __first_false = _VSTD::__stable_partition<_PredRef>(__first, __m1, __pred, __len_half, __p, __bit);
36833e519524SHoward Hinnant__first_half_done:
36843e519524SHoward Hinnant    // TTTFFFFF?????????T
36853e519524SHoward Hinnant    // f  ff   m        l
36863e519524SHoward Hinnant    // recurse on [__m, __last], except increase __m until *(__m) is false, *__last know to be true
36873e519524SHoward Hinnant    __m1 = __m;
36883e519524SHoward Hinnant    _BidirectionalIterator __second_false = __last;
36893e519524SHoward Hinnant    ++__second_false;
36903e519524SHoward Hinnant    __len_half = __len - __len2;
36913e519524SHoward Hinnant    while (__pred(*__m1))
36923e519524SHoward Hinnant    {
36933e519524SHoward Hinnant        if (++__m1 == __last)
36943e519524SHoward Hinnant            goto __second_half_done;
36953e519524SHoward Hinnant        --__len_half;
36963e519524SHoward Hinnant    }
36973e519524SHoward Hinnant    // TTTFFFFFTTTF?????T
36983e519524SHoward Hinnant    // f  ff   m  m1    l
36991968804aSArthur O'Dwyer    __second_false = _VSTD::__stable_partition<_PredRef>(__m1, __last, __pred, __len_half, __p, __bit);
37003e519524SHoward Hinnant__second_half_done:
37013e519524SHoward Hinnant    // TTTFFFFFTTTTTFFFFF
37023e519524SHoward Hinnant    // f  ff   m    sf  l
3703ce48a113SHoward Hinnant    return _VSTD::rotate(__first_false, __m, __second_false);
37043e519524SHoward Hinnant    // TTTTTTTTFFFFFFFFFF
37053e519524SHoward Hinnant    //         |
37063e519524SHoward Hinnant}
37073e519524SHoward Hinnant
37083e519524SHoward Hinnanttemplate <class _Predicate, class _BidirectionalIterator>
37093e519524SHoward Hinnant_BidirectionalIterator
37103e519524SHoward Hinnant__stable_partition(_BidirectionalIterator __first, _BidirectionalIterator __last, _Predicate __pred,
37113e519524SHoward Hinnant                   bidirectional_iterator_tag)
37123e519524SHoward Hinnant{
37133e519524SHoward Hinnant    typedef typename iterator_traits<_BidirectionalIterator>::difference_type difference_type;
37143e519524SHoward Hinnant    typedef typename iterator_traits<_BidirectionalIterator>::value_type value_type;
37153e519524SHoward Hinnant    const difference_type __alloc_limit = 4;  // might want to make this a function of trivial assignment
37163e519524SHoward Hinnant    // Either prove all true and return __first or point to first false
37173e519524SHoward Hinnant    while (true)
37183e519524SHoward Hinnant    {
37193e519524SHoward Hinnant        if (__first == __last)
37203e519524SHoward Hinnant            return __first;
37213e519524SHoward Hinnant        if (!__pred(*__first))
37223e519524SHoward Hinnant            break;
37233e519524SHoward Hinnant        ++__first;
37243e519524SHoward Hinnant    }
37253e519524SHoward Hinnant    // __first points to first false, everything prior to __first is already set.
37263e519524SHoward Hinnant    // Either prove [__first, __last) is all false and return __first, or point __last to last true
37273e519524SHoward Hinnant    do
37283e519524SHoward Hinnant    {
37293e519524SHoward Hinnant        if (__first == --__last)
37303e519524SHoward Hinnant            return __first;
37313e519524SHoward Hinnant    } while (!__pred(*__last));
37323e519524SHoward Hinnant    // We now have a reduced range [__first, __last]
37333e519524SHoward Hinnant    // *__first is known to be false
37343e519524SHoward Hinnant    // *__last is known to be true
37353e519524SHoward Hinnant    // __len >= 2
3736ce48a113SHoward Hinnant    difference_type __len = _VSTD::distance(__first, __last) + 1;
37373e519524SHoward Hinnant    pair<value_type*, ptrdiff_t> __p(0, 0);
37383e519524SHoward Hinnant    unique_ptr<value_type, __return_temporary_buffer> __h;
37393e519524SHoward Hinnant    if (__len >= __alloc_limit)
37403e519524SHoward Hinnant    {
3741ce48a113SHoward Hinnant        __p = _VSTD::get_temporary_buffer<value_type>(__len);
37423e519524SHoward Hinnant        __h.reset(__p.first);
37433e519524SHoward Hinnant    }
37441968804aSArthur O'Dwyer    return _VSTD::__stable_partition<typename add_lvalue_reference<_Predicate>::type>
37453e519524SHoward Hinnant                             (__first, __last, __pred, __len, __p, bidirectional_iterator_tag());
37463e519524SHoward Hinnant}
37473e519524SHoward Hinnant
37483e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Predicate>
37493e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
37503e519524SHoward Hinnant_ForwardIterator
37513e519524SHoward Hinnantstable_partition(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred)
37523e519524SHoward Hinnant{
37531968804aSArthur O'Dwyer    return _VSTD::__stable_partition<typename add_lvalue_reference<_Predicate>::type>
37543e519524SHoward Hinnant                             (__first, __last, __pred, typename iterator_traits<_ForwardIterator>::iterator_category());
37553e519524SHoward Hinnant}
37563e519524SHoward Hinnant
37573e519524SHoward Hinnant// is_sorted_until
37583e519524SHoward Hinnant
37593e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Compare>
37601362d7efSNico Weber_LIBCPP_NODISCARD_EXT _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
37613e519524SHoward Hinnantis_sorted_until(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp)
37623e519524SHoward Hinnant{
37633e519524SHoward Hinnant    if (__first != __last)
37643e519524SHoward Hinnant    {
37653e519524SHoward Hinnant        _ForwardIterator __i = __first;
37663e519524SHoward Hinnant        while (++__i != __last)
37673e519524SHoward Hinnant        {
37683e519524SHoward Hinnant            if (__comp(*__i, *__first))
37693e519524SHoward Hinnant                return __i;
37703e519524SHoward Hinnant            __first = __i;
37713e519524SHoward Hinnant        }
37723e519524SHoward Hinnant    }
37733e519524SHoward Hinnant    return __last;
37743e519524SHoward Hinnant}
37753e519524SHoward Hinnant
37763e519524SHoward Hinnanttemplate<class _ForwardIterator>
37771362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
37781362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
37793e519524SHoward Hinnant_ForwardIterator
37803e519524SHoward Hinnantis_sorted_until(_ForwardIterator __first, _ForwardIterator __last)
37813e519524SHoward Hinnant{
3782ce48a113SHoward Hinnant    return _VSTD::is_sorted_until(__first, __last, __less<typename iterator_traits<_ForwardIterator>::value_type>());
37833e519524SHoward Hinnant}
37843e519524SHoward Hinnant
37853e519524SHoward Hinnant// is_sorted
37863e519524SHoward Hinnant
37873e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Compare>
37881362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
37891362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
37903e519524SHoward Hinnantbool
37913e519524SHoward Hinnantis_sorted(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp)
37923e519524SHoward Hinnant{
3793ce48a113SHoward Hinnant    return _VSTD::is_sorted_until(__first, __last, __comp) == __last;
37943e519524SHoward Hinnant}
37953e519524SHoward Hinnant
37963e519524SHoward Hinnanttemplate<class _ForwardIterator>
37971362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
37981362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
37993e519524SHoward Hinnantbool
38003e519524SHoward Hinnantis_sorted(_ForwardIterator __first, _ForwardIterator __last)
38013e519524SHoward Hinnant{
3802ce48a113SHoward Hinnant    return _VSTD::is_sorted(__first, __last, __less<typename iterator_traits<_ForwardIterator>::value_type>());
38033e519524SHoward Hinnant}
38043e519524SHoward Hinnant
38053e519524SHoward Hinnant// sort
38063e519524SHoward Hinnant
38073e519524SHoward Hinnant// stable, 2-3 compares, 0-2 swaps
38083e519524SHoward Hinnant
38093e519524SHoward Hinnanttemplate <class _Compare, class _ForwardIterator>
3810*b6ffece3SJordan Rupprechtunsigned
38113e519524SHoward Hinnant__sort3(_ForwardIterator __x, _ForwardIterator __y, _ForwardIterator __z, _Compare __c)
38123e519524SHoward Hinnant{
38133e519524SHoward Hinnant    unsigned __r = 0;
38143e519524SHoward Hinnant    if (!__c(*__y, *__x))          // if x <= y
38153e519524SHoward Hinnant    {
38163e519524SHoward Hinnant        if (!__c(*__z, *__y))      // if y <= z
38173e519524SHoward Hinnant            return __r;            // x <= y && y <= z
38183e519524SHoward Hinnant                                   // x <= y && y > z
38193e519524SHoward Hinnant        swap(*__y, *__z);          // x <= z && y < z
38203e519524SHoward Hinnant        __r = 1;
38213e519524SHoward Hinnant        if (__c(*__y, *__x))       // if x > y
38223e519524SHoward Hinnant        {
38233e519524SHoward Hinnant            swap(*__x, *__y);      // x < y && y <= z
38243e519524SHoward Hinnant            __r = 2;
38253e519524SHoward Hinnant        }
38263e519524SHoward Hinnant        return __r;                // x <= y && y < z
38273e519524SHoward Hinnant    }
38283e519524SHoward Hinnant    if (__c(*__z, *__y))           // x > y, if y > z
38293e519524SHoward Hinnant    {
38303e519524SHoward Hinnant        swap(*__x, *__z);          // x < y && y < z
38313e519524SHoward Hinnant        __r = 1;
38323e519524SHoward Hinnant        return __r;
38333e519524SHoward Hinnant    }
38343e519524SHoward Hinnant    swap(*__x, *__y);              // x > y && y <= z
38353e519524SHoward Hinnant    __r = 1;                       // x < y && x <= z
38363e519524SHoward Hinnant    if (__c(*__z, *__y))           // if y > z
38373e519524SHoward Hinnant    {
38383e519524SHoward Hinnant        swap(*__y, *__z);          // x <= y && y < z
38393e519524SHoward Hinnant        __r = 2;
38403e519524SHoward Hinnant    }
38413e519524SHoward Hinnant    return __r;
38423e519524SHoward Hinnant}                                  // x <= y && y <= z
38433e519524SHoward Hinnant
38443e519524SHoward Hinnant// stable, 3-6 compares, 0-5 swaps
38453e519524SHoward Hinnant
38463e519524SHoward Hinnanttemplate <class _Compare, class _ForwardIterator>
38473e519524SHoward Hinnantunsigned
38483e519524SHoward Hinnant__sort4(_ForwardIterator __x1, _ForwardIterator __x2, _ForwardIterator __x3,
38493e519524SHoward Hinnant            _ForwardIterator __x4, _Compare __c)
38503e519524SHoward Hinnant{
38511968804aSArthur O'Dwyer    unsigned __r = _VSTD::__sort3<_Compare>(__x1, __x2, __x3, __c);
38523e519524SHoward Hinnant    if (__c(*__x4, *__x3))
38533e519524SHoward Hinnant    {
38543e519524SHoward Hinnant        swap(*__x3, *__x4);
38553e519524SHoward Hinnant        ++__r;
38563e519524SHoward Hinnant        if (__c(*__x3, *__x2))
38573e519524SHoward Hinnant        {
38583e519524SHoward Hinnant            swap(*__x2, *__x3);
38593e519524SHoward Hinnant            ++__r;
38603e519524SHoward Hinnant            if (__c(*__x2, *__x1))
38613e519524SHoward Hinnant            {
38623e519524SHoward Hinnant                swap(*__x1, *__x2);
38633e519524SHoward Hinnant                ++__r;
38643e519524SHoward Hinnant            }
38653e519524SHoward Hinnant        }
38663e519524SHoward Hinnant    }
38673e519524SHoward Hinnant    return __r;
38683e519524SHoward Hinnant}
38693e519524SHoward Hinnant
38703e519524SHoward Hinnant// stable, 4-10 compares, 0-9 swaps
38713e519524SHoward Hinnant
38723e519524SHoward Hinnanttemplate <class _Compare, class _ForwardIterator>
3873835140a4SLouis Dionne_LIBCPP_HIDDEN
38743e519524SHoward Hinnantunsigned
38753e519524SHoward Hinnant__sort5(_ForwardIterator __x1, _ForwardIterator __x2, _ForwardIterator __x3,
38763e519524SHoward Hinnant            _ForwardIterator __x4, _ForwardIterator __x5, _Compare __c)
38773e519524SHoward Hinnant{
38781968804aSArthur O'Dwyer    unsigned __r = _VSTD::__sort4<_Compare>(__x1, __x2, __x3, __x4, __c);
38793e519524SHoward Hinnant    if (__c(*__x5, *__x4))
38803e519524SHoward Hinnant    {
38813e519524SHoward Hinnant        swap(*__x4, *__x5);
38823e519524SHoward Hinnant        ++__r;
38833e519524SHoward Hinnant        if (__c(*__x4, *__x3))
38843e519524SHoward Hinnant        {
38853e519524SHoward Hinnant            swap(*__x3, *__x4);
38863e519524SHoward Hinnant            ++__r;
38873e519524SHoward Hinnant            if (__c(*__x3, *__x2))
38883e519524SHoward Hinnant            {
38893e519524SHoward Hinnant                swap(*__x2, *__x3);
38903e519524SHoward Hinnant                ++__r;
38913e519524SHoward Hinnant                if (__c(*__x2, *__x1))
38923e519524SHoward Hinnant                {
38933e519524SHoward Hinnant                    swap(*__x1, *__x2);
38943e519524SHoward Hinnant                    ++__r;
38953e519524SHoward Hinnant                }
38963e519524SHoward Hinnant            }
38973e519524SHoward Hinnant        }
38983e519524SHoward Hinnant    }
38993e519524SHoward Hinnant    return __r;
39003e519524SHoward Hinnant}
39013e519524SHoward Hinnant
39023e519524SHoward Hinnant// Assumes size > 0
39031d7c39e1SArthur O'Dwyertemplate <class _Compare, class _BidirectionalIterator>
3904*b6ffece3SJordan Rupprechtvoid
39051d7c39e1SArthur O'Dwyer__selection_sort(_BidirectionalIterator __first, _BidirectionalIterator __last, _Compare __comp)
39063e519524SHoward Hinnant{
39071d7c39e1SArthur O'Dwyer    _BidirectionalIterator __lm1 = __last;
39083e519524SHoward Hinnant    for (--__lm1; __first != __lm1; ++__first)
39093e519524SHoward Hinnant    {
39101d7c39e1SArthur O'Dwyer        _BidirectionalIterator __i = _VSTD::min_element<_BidirectionalIterator,
39113e519524SHoward Hinnant                                                        typename add_lvalue_reference<_Compare>::type>
39123e519524SHoward Hinnant                                                       (__first, __last, __comp);
39133e519524SHoward Hinnant        if (__i != __first)
39143e519524SHoward Hinnant            swap(*__first, *__i);
39153e519524SHoward Hinnant    }
39163e519524SHoward Hinnant}
39173e519524SHoward Hinnant
39181d7c39e1SArthur O'Dwyertemplate <class _Compare, class _BidirectionalIterator>
39193e519524SHoward Hinnantvoid
39201d7c39e1SArthur O'Dwyer__insertion_sort(_BidirectionalIterator __first, _BidirectionalIterator __last, _Compare __comp)
39213e519524SHoward Hinnant{
39221d7c39e1SArthur O'Dwyer    typedef typename iterator_traits<_BidirectionalIterator>::value_type value_type;
39233e519524SHoward Hinnant    if (__first != __last)
39243e519524SHoward Hinnant    {
39251d7c39e1SArthur O'Dwyer        _BidirectionalIterator __i = __first;
39263e519524SHoward Hinnant        for (++__i; __i != __last; ++__i)
39273e519524SHoward Hinnant        {
39281d7c39e1SArthur O'Dwyer            _BidirectionalIterator __j = __i;
3929ce48a113SHoward Hinnant            value_type __t(_VSTD::move(*__j));
39301d7c39e1SArthur O'Dwyer            for (_BidirectionalIterator __k = __i; __k != __first && __comp(__t,  *--__k); --__j)
3931ce48a113SHoward Hinnant                *__j = _VSTD::move(*__k);
3932ce48a113SHoward Hinnant            *__j = _VSTD::move(__t);
39333e519524SHoward Hinnant        }
39343e519524SHoward Hinnant    }
39353e519524SHoward Hinnant}
39363e519524SHoward Hinnant
39373e519524SHoward Hinnanttemplate <class _Compare, class _RandomAccessIterator>
39383e519524SHoward Hinnantvoid
39393e519524SHoward Hinnant__insertion_sort_3(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
39403e519524SHoward Hinnant{
39413e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
39423e519524SHoward Hinnant    _RandomAccessIterator __j = __first+2;
39431968804aSArthur O'Dwyer    _VSTD::__sort3<_Compare>(__first, __first+1, __j, __comp);
39443e519524SHoward Hinnant    for (_RandomAccessIterator __i = __j+1; __i != __last; ++__i)
39453e519524SHoward Hinnant    {
39463e519524SHoward Hinnant        if (__comp(*__i, *__j))
39473e519524SHoward Hinnant        {
3948ce48a113SHoward Hinnant            value_type __t(_VSTD::move(*__i));
39493e519524SHoward Hinnant            _RandomAccessIterator __k = __j;
39503e519524SHoward Hinnant            __j = __i;
39513e519524SHoward Hinnant            do
39523e519524SHoward Hinnant            {
3953ce48a113SHoward Hinnant                *__j = _VSTD::move(*__k);
39543e519524SHoward Hinnant                __j = __k;
39553e519524SHoward Hinnant            } while (__j != __first && __comp(__t, *--__k));
3956ce48a113SHoward Hinnant            *__j = _VSTD::move(__t);
39573e519524SHoward Hinnant        }
39583e519524SHoward Hinnant        __j = __i;
39593e519524SHoward Hinnant    }
39603e519524SHoward Hinnant}
39613e519524SHoward Hinnant
39623e519524SHoward Hinnanttemplate <class _Compare, class _RandomAccessIterator>
39633e519524SHoward Hinnantbool
39643e519524SHoward Hinnant__insertion_sort_incomplete(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
39653e519524SHoward Hinnant{
39663e519524SHoward Hinnant    switch (__last - __first)
39673e519524SHoward Hinnant    {
39683e519524SHoward Hinnant    case 0:
39693e519524SHoward Hinnant    case 1:
39703e519524SHoward Hinnant        return true;
39713e519524SHoward Hinnant    case 2:
39723e519524SHoward Hinnant        if (__comp(*--__last, *__first))
39733e519524SHoward Hinnant            swap(*__first, *__last);
39743e519524SHoward Hinnant        return true;
39753e519524SHoward Hinnant    case 3:
3976ce48a113SHoward Hinnant        _VSTD::__sort3<_Compare>(__first, __first+1, --__last, __comp);
39773e519524SHoward Hinnant        return true;
39783e519524SHoward Hinnant    case 4:
3979ce48a113SHoward Hinnant        _VSTD::__sort4<_Compare>(__first, __first+1, __first+2, --__last, __comp);
39803e519524SHoward Hinnant        return true;
39813e519524SHoward Hinnant    case 5:
3982ce48a113SHoward Hinnant        _VSTD::__sort5<_Compare>(__first, __first+1, __first+2, __first+3, --__last, __comp);
39833e519524SHoward Hinnant        return true;
39843e519524SHoward Hinnant    }
39853e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
39863e519524SHoward Hinnant    _RandomAccessIterator __j = __first+2;
39871968804aSArthur O'Dwyer    _VSTD::__sort3<_Compare>(__first, __first+1, __j, __comp);
39883e519524SHoward Hinnant    const unsigned __limit = 8;
39893e519524SHoward Hinnant    unsigned __count = 0;
39903e519524SHoward Hinnant    for (_RandomAccessIterator __i = __j+1; __i != __last; ++__i)
39913e519524SHoward Hinnant    {
39923e519524SHoward Hinnant        if (__comp(*__i, *__j))
39933e519524SHoward Hinnant        {
3994ce48a113SHoward Hinnant            value_type __t(_VSTD::move(*__i));
39953e519524SHoward Hinnant            _RandomAccessIterator __k = __j;
39963e519524SHoward Hinnant            __j = __i;
39973e519524SHoward Hinnant            do
39983e519524SHoward Hinnant            {
3999ce48a113SHoward Hinnant                *__j = _VSTD::move(*__k);
40003e519524SHoward Hinnant                __j = __k;
40013e519524SHoward Hinnant            } while (__j != __first && __comp(__t, *--__k));
4002ce48a113SHoward Hinnant            *__j = _VSTD::move(__t);
40033e519524SHoward Hinnant            if (++__count == __limit)
40043e519524SHoward Hinnant                return ++__i == __last;
40053e519524SHoward Hinnant        }
40063e519524SHoward Hinnant        __j = __i;
40073e519524SHoward Hinnant    }
40083e519524SHoward Hinnant    return true;
40093e519524SHoward Hinnant}
40103e519524SHoward Hinnant
40111d7c39e1SArthur O'Dwyertemplate <class _Compare, class _BidirectionalIterator>
40123e519524SHoward Hinnantvoid
40131d7c39e1SArthur O'Dwyer__insertion_sort_move(_BidirectionalIterator __first1, _BidirectionalIterator __last1,
40141d7c39e1SArthur O'Dwyer                      typename iterator_traits<_BidirectionalIterator>::value_type* __first2, _Compare __comp)
40153e519524SHoward Hinnant{
40161d7c39e1SArthur O'Dwyer    typedef typename iterator_traits<_BidirectionalIterator>::value_type value_type;
40173e519524SHoward Hinnant    if (__first1 != __last1)
40183e519524SHoward Hinnant    {
40193e519524SHoward Hinnant        __destruct_n __d(0);
40203e519524SHoward Hinnant        unique_ptr<value_type, __destruct_n&> __h(__first2, __d);
40213e519524SHoward Hinnant        value_type* __last2 = __first2;
4022be4c657bSArthur O'Dwyer        ::new ((void*)__last2) value_type(_VSTD::move(*__first1));
4023527a7fdfSBruce Mitchener        __d.template __incr<value_type>();
40243e519524SHoward Hinnant        for (++__last2; ++__first1 != __last1; ++__last2)
40253e519524SHoward Hinnant        {
40263e519524SHoward Hinnant            value_type* __j2 = __last2;
40273e519524SHoward Hinnant            value_type* __i2 = __j2;
40283e519524SHoward Hinnant            if (__comp(*__first1, *--__i2))
40293e519524SHoward Hinnant            {
4030be4c657bSArthur O'Dwyer                ::new ((void*)__j2) value_type(_VSTD::move(*__i2));
4031527a7fdfSBruce Mitchener                __d.template __incr<value_type>();
40323e519524SHoward Hinnant                for (--__j2; __i2 != __first2 && __comp(*__first1,  *--__i2); --__j2)
4033ce48a113SHoward Hinnant                    *__j2 = _VSTD::move(*__i2);
4034ce48a113SHoward Hinnant                *__j2 = _VSTD::move(*__first1);
40353e519524SHoward Hinnant            }
40363e519524SHoward Hinnant            else
40373e519524SHoward Hinnant            {
4038be4c657bSArthur O'Dwyer                ::new ((void*)__j2) value_type(_VSTD::move(*__first1));
4039527a7fdfSBruce Mitchener                __d.template __incr<value_type>();
40403e519524SHoward Hinnant            }
40413e519524SHoward Hinnant        }
40423e519524SHoward Hinnant        __h.release();
40433e519524SHoward Hinnant    }
40443e519524SHoward Hinnant}
40453e519524SHoward Hinnant
40463e519524SHoward Hinnanttemplate <class _Compare, class _RandomAccessIterator>
40473e519524SHoward Hinnantvoid
40483e519524SHoward Hinnant__sort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
40493e519524SHoward Hinnant{
40503e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
40513e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
4052ca740483SHoward Hinnant    const difference_type __limit = is_trivially_copy_constructible<value_type>::value &&
4053ca740483SHoward Hinnant                                    is_trivially_copy_assignable<value_type>::value ? 30 : 6;
40543e519524SHoward Hinnant    while (true)
40553e519524SHoward Hinnant    {
40563e519524SHoward Hinnant    __restart:
40573e519524SHoward Hinnant        difference_type __len = __last - __first;
40583e519524SHoward Hinnant        switch (__len)
40593e519524SHoward Hinnant        {
40603e519524SHoward Hinnant        case 0:
40613e519524SHoward Hinnant        case 1:
40623e519524SHoward Hinnant            return;
40633e519524SHoward Hinnant        case 2:
40643e519524SHoward Hinnant            if (__comp(*--__last, *__first))
40653e519524SHoward Hinnant                swap(*__first, *__last);
40663e519524SHoward Hinnant            return;
40673e519524SHoward Hinnant        case 3:
4068ce48a113SHoward Hinnant            _VSTD::__sort3<_Compare>(__first, __first+1, --__last, __comp);
40693e519524SHoward Hinnant            return;
40703e519524SHoward Hinnant        case 4:
4071ce48a113SHoward Hinnant            _VSTD::__sort4<_Compare>(__first, __first+1, __first+2, --__last, __comp);
40723e519524SHoward Hinnant            return;
40733e519524SHoward Hinnant        case 5:
4074ce48a113SHoward Hinnant            _VSTD::__sort5<_Compare>(__first, __first+1, __first+2, __first+3, --__last, __comp);
40753e519524SHoward Hinnant            return;
40763e519524SHoward Hinnant        }
40773e519524SHoward Hinnant        if (__len <= __limit)
40783e519524SHoward Hinnant        {
4079ce48a113SHoward Hinnant            _VSTD::__insertion_sort_3<_Compare>(__first, __last, __comp);
40803e519524SHoward Hinnant            return;
40813e519524SHoward Hinnant        }
40823e519524SHoward Hinnant        // __len > 5
40833e519524SHoward Hinnant        _RandomAccessIterator __m = __first;
40843e519524SHoward Hinnant        _RandomAccessIterator __lm1 = __last;
40853e519524SHoward Hinnant        --__lm1;
40863e519524SHoward Hinnant        unsigned __n_swaps;
40873e519524SHoward Hinnant        {
40883e519524SHoward Hinnant        difference_type __delta;
40893e519524SHoward Hinnant        if (__len >= 1000)
40903e519524SHoward Hinnant        {
40913e519524SHoward Hinnant            __delta = __len/2;
40923e519524SHoward Hinnant            __m += __delta;
40933e519524SHoward Hinnant            __delta /= 2;
4094ce48a113SHoward Hinnant            __n_swaps = _VSTD::__sort5<_Compare>(__first, __first + __delta, __m, __m+__delta, __lm1, __comp);
40953e519524SHoward Hinnant        }
40963e519524SHoward Hinnant        else
40973e519524SHoward Hinnant        {
40983e519524SHoward Hinnant            __delta = __len/2;
40993e519524SHoward Hinnant            __m += __delta;
4100ce48a113SHoward Hinnant            __n_swaps = _VSTD::__sort3<_Compare>(__first, __m, __lm1, __comp);
41013e519524SHoward Hinnant        }
41023e519524SHoward Hinnant        }
41033e519524SHoward Hinnant        // *__m is median
41043e519524SHoward Hinnant        // partition [__first, __m) < *__m and *__m <= [__m, __last)
41053e519524SHoward Hinnant        // (this inhibits tossing elements equivalent to __m around unnecessarily)
41063e519524SHoward Hinnant        _RandomAccessIterator __i = __first;
41073e519524SHoward Hinnant        _RandomAccessIterator __j = __lm1;
41083e519524SHoward Hinnant        // j points beyond range to be tested, *__m is known to be <= *__lm1
41093e519524SHoward Hinnant        // The search going up is known to be guarded but the search coming down isn't.
41103e519524SHoward Hinnant        // Prime the downward search with a guard.
41113e519524SHoward Hinnant        if (!__comp(*__i, *__m))  // if *__first == *__m
41123e519524SHoward Hinnant        {
41133e519524SHoward Hinnant            // *__first == *__m, *__first doesn't go in first part
41143e519524SHoward Hinnant            // manually guard downward moving __j against __i
41153e519524SHoward Hinnant            while (true)
41163e519524SHoward Hinnant            {
41173e519524SHoward Hinnant                if (__i == --__j)
41183e519524SHoward Hinnant                {
41193e519524SHoward Hinnant                    // *__first == *__m, *__m <= all other elements
41203e519524SHoward Hinnant                    // Parition instead into [__first, __i) == *__first and *__first < [__i, __last)
41213e519524SHoward Hinnant                    ++__i;  // __first + 1
41223e519524SHoward Hinnant                    __j = __last;
41233e519524SHoward Hinnant                    if (!__comp(*__first, *--__j))  // we need a guard if *__first == *(__last-1)
41243e519524SHoward Hinnant                    {
41253e519524SHoward Hinnant                        while (true)
41263e519524SHoward Hinnant                        {
41273e519524SHoward Hinnant                            if (__i == __j)
41283e519524SHoward Hinnant                                return;  // [__first, __last) all equivalent elements
41293e519524SHoward Hinnant                            if (__comp(*__first, *__i))
41303e519524SHoward Hinnant                            {
41313e519524SHoward Hinnant                                swap(*__i, *__j);
41323e519524SHoward Hinnant                                ++__n_swaps;
41333e519524SHoward Hinnant                                ++__i;
41343e519524SHoward Hinnant                                break;
41353e519524SHoward Hinnant                            }
41363e519524SHoward Hinnant                            ++__i;
41373e519524SHoward Hinnant                        }
41383e519524SHoward Hinnant                    }
41393e519524SHoward Hinnant                    // [__first, __i) == *__first and *__first < [__j, __last) and __j == __last - 1
41403e519524SHoward Hinnant                    if (__i == __j)
41413e519524SHoward Hinnant                        return;
41423e519524SHoward Hinnant                    while (true)
41433e519524SHoward Hinnant                    {
41443e519524SHoward Hinnant                        while (!__comp(*__first, *__i))
41453e519524SHoward Hinnant                            ++__i;
41463e519524SHoward Hinnant                        while (__comp(*__first, *--__j))
41473e519524SHoward Hinnant                            ;
41483e519524SHoward Hinnant                        if (__i >= __j)
41493e519524SHoward Hinnant                            break;
41503e519524SHoward Hinnant                        swap(*__i, *__j);
41513e519524SHoward Hinnant                        ++__n_swaps;
41523e519524SHoward Hinnant                        ++__i;
41533e519524SHoward Hinnant                    }
41543e519524SHoward Hinnant                    // [__first, __i) == *__first and *__first < [__i, __last)
4155b6f19174SArthur O'Dwyer                    // The first part is sorted, sort the second part
4156ce48a113SHoward Hinnant                    // _VSTD::__sort<_Compare>(__i, __last, __comp);
41573e519524SHoward Hinnant                    __first = __i;
41583e519524SHoward Hinnant                    goto __restart;
41593e519524SHoward Hinnant                }
41603e519524SHoward Hinnant                if (__comp(*__j, *__m))
41613e519524SHoward Hinnant                {
41623e519524SHoward Hinnant                    swap(*__i, *__j);
41633e519524SHoward Hinnant                    ++__n_swaps;
41643e519524SHoward Hinnant                    break;  // found guard for downward moving __j, now use unguarded partition
41653e519524SHoward Hinnant                }
41663e519524SHoward Hinnant            }
41673e519524SHoward Hinnant        }
41683e519524SHoward Hinnant        // It is known that *__i < *__m
41693e519524SHoward Hinnant        ++__i;
41703e519524SHoward Hinnant        // j points beyond range to be tested, *__m is known to be <= *__lm1
41713e519524SHoward Hinnant        // if not yet partitioned...
41723e519524SHoward Hinnant        if (__i < __j)
41733e519524SHoward Hinnant        {
41743e519524SHoward Hinnant            // known that *(__i - 1) < *__m
41753e519524SHoward Hinnant            // known that __i <= __m
41763e519524SHoward Hinnant            while (true)
41773e519524SHoward Hinnant            {
41783e519524SHoward Hinnant                // __m still guards upward moving __i
41793e519524SHoward Hinnant                while (__comp(*__i, *__m))
41803e519524SHoward Hinnant                    ++__i;
41813e519524SHoward Hinnant                // It is now known that a guard exists for downward moving __j
41823e519524SHoward Hinnant                while (!__comp(*--__j, *__m))
41833e519524SHoward Hinnant                    ;
41843e519524SHoward Hinnant                if (__i > __j)
41853e519524SHoward Hinnant                    break;
41863e519524SHoward Hinnant                swap(*__i, *__j);
41873e519524SHoward Hinnant                ++__n_swaps;
41883e519524SHoward Hinnant                // It is known that __m != __j
41893e519524SHoward Hinnant                // If __m just moved, follow it
41903e519524SHoward Hinnant                if (__m == __i)
41913e519524SHoward Hinnant                    __m = __j;
41923e519524SHoward Hinnant                ++__i;
41933e519524SHoward Hinnant            }
41943e519524SHoward Hinnant        }
41953e519524SHoward Hinnant        // [__first, __i) < *__m and *__m <= [__i, __last)
41963e519524SHoward Hinnant        if (__i != __m && __comp(*__m, *__i))
41973e519524SHoward Hinnant        {
41983e519524SHoward Hinnant            swap(*__i, *__m);
41993e519524SHoward Hinnant            ++__n_swaps;
42003e519524SHoward Hinnant        }
42013e519524SHoward Hinnant        // [__first, __i) < *__i and *__i <= [__i+1, __last)
42023e519524SHoward Hinnant        // If we were given a perfect partition, see if insertion sort is quick...
42033e519524SHoward Hinnant        if (__n_swaps == 0)
42043e519524SHoward Hinnant        {
4205ce48a113SHoward Hinnant            bool __fs = _VSTD::__insertion_sort_incomplete<_Compare>(__first, __i, __comp);
4206ce48a113SHoward Hinnant            if (_VSTD::__insertion_sort_incomplete<_Compare>(__i+1, __last, __comp))
42073e519524SHoward Hinnant            {
42083e519524SHoward Hinnant                if (__fs)
42093e519524SHoward Hinnant                    return;
42103e519524SHoward Hinnant                __last = __i;
42113e519524SHoward Hinnant                continue;
42123e519524SHoward Hinnant            }
42133e519524SHoward Hinnant            else
42143e519524SHoward Hinnant            {
42153e519524SHoward Hinnant                if (__fs)
42163e519524SHoward Hinnant                {
42173e519524SHoward Hinnant                    __first = ++__i;
42183e519524SHoward Hinnant                    continue;
42193e519524SHoward Hinnant                }
42203e519524SHoward Hinnant            }
42213e519524SHoward Hinnant        }
42223e519524SHoward Hinnant        // sort smaller range with recursive call and larger with tail recursion elimination
42233e519524SHoward Hinnant        if (__i - __first < __last - __i)
42243e519524SHoward Hinnant        {
4225ce48a113SHoward Hinnant            _VSTD::__sort<_Compare>(__first, __i, __comp);
4226ce48a113SHoward Hinnant            // _VSTD::__sort<_Compare>(__i+1, __last, __comp);
42273e519524SHoward Hinnant            __first = ++__i;
42283e519524SHoward Hinnant        }
42293e519524SHoward Hinnant        else
42303e519524SHoward Hinnant        {
4231ce48a113SHoward Hinnant            _VSTD::__sort<_Compare>(__i+1, __last, __comp);
4232ce48a113SHoward Hinnant            // _VSTD::__sort<_Compare>(__first, __i, __comp);
42333e519524SHoward Hinnant            __last = __i;
42343e519524SHoward Hinnant        }
42353e519524SHoward Hinnant    }
42363e519524SHoward Hinnant}
42373e519524SHoward Hinnant
4238493f1407SArthur O'Dwyertemplate <class _Compare, class _Tp>
42393e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
42403e519524SHoward Hinnantvoid
4241493f1407SArthur O'Dwyer__sort(_Tp** __first, _Tp** __last, __less<_Tp*>&)
42423e519524SHoward Hinnant{
4243493f1407SArthur O'Dwyer    __less<uintptr_t> __comp;
4244493f1407SArthur O'Dwyer    _VSTD::__sort<__less<uintptr_t>&, uintptr_t*>((uintptr_t*)__first, (uintptr_t*)__last, __comp);
4245f554add5SHoward Hinnant}
4246f554add5SHoward Hinnant
4247f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<char>&, char*>(char*, char*, __less<char>&))
4248f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<wchar_t>&, wchar_t*>(wchar_t*, wchar_t*, __less<wchar_t>&))
4249f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<signed char>&, signed char*>(signed char*, signed char*, __less<signed char>&))
4250f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<unsigned char>&, unsigned char*>(unsigned char*, unsigned char*, __less<unsigned char>&))
4251f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<short>&, short*>(short*, short*, __less<short>&))
4252f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<unsigned short>&, unsigned short*>(unsigned short*, unsigned short*, __less<unsigned short>&))
4253f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<int>&, int*>(int*, int*, __less<int>&))
4254f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<unsigned>&, unsigned*>(unsigned*, unsigned*, __less<unsigned>&))
4255f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<long>&, long*>(long*, long*, __less<long>&))
4256f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<unsigned long>&, unsigned long*>(unsigned long*, unsigned long*, __less<unsigned long>&))
4257f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<long long>&, long long*>(long long*, long long*, __less<long long>&))
4258f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<unsigned long long>&, unsigned long long*>(unsigned long long*, unsigned long long*, __less<unsigned long long>&))
4259f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<float>&, float*>(float*, float*, __less<float>&))
4260f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<double>&, double*>(double*, double*, __less<double>&))
4261f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<long double>&, long double*>(long double*, long double*, __less<long double>&))
42623e519524SHoward Hinnant
4263f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<char>&, char*>(char*, char*, __less<char>&))
4264f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<wchar_t>&, wchar_t*>(wchar_t*, wchar_t*, __less<wchar_t>&))
4265f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<signed char>&, signed char*>(signed char*, signed char*, __less<signed char>&))
4266f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<unsigned char>&, unsigned char*>(unsigned char*, unsigned char*, __less<unsigned char>&))
4267f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<short>&, short*>(short*, short*, __less<short>&))
4268f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<unsigned short>&, unsigned short*>(unsigned short*, unsigned short*, __less<unsigned short>&))
4269f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<int>&, int*>(int*, int*, __less<int>&))
4270f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<unsigned>&, unsigned*>(unsigned*, unsigned*, __less<unsigned>&))
4271f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<long>&, long*>(long*, long*, __less<long>&))
4272f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<unsigned long>&, unsigned long*>(unsigned long*, unsigned long*, __less<unsigned long>&))
4273f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<long long>&, long long*>(long long*, long long*, __less<long long>&))
4274f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<unsigned long long>&, unsigned long long*>(unsigned long long*, unsigned long long*, __less<unsigned long long>&))
4275f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<float>&, float*>(float*, float*, __less<float>&))
4276f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<double>&, double*>(double*, double*, __less<double>&))
4277f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<long double>&, long double*>(long double*, long double*, __less<long double>&))
42783e519524SHoward Hinnant
4279f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS unsigned __sort5<__less<long double>&, long double*>(long double*, long double*, long double*, long double*, long double*, __less<long double>&))
42803e519524SHoward Hinnant
42813e519524SHoward Hinnant// lower_bound
42823e519524SHoward Hinnant
42833e519524SHoward Hinnanttemplate <class _Compare, class _ForwardIterator, class _Tp>
4284d57c03ddSMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
4285e4383379SHoward Hinnant__lower_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
42863e519524SHoward Hinnant{
42873e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator>::difference_type difference_type;
4288ce48a113SHoward Hinnant    difference_type __len = _VSTD::distance(__first, __last);
42893e519524SHoward Hinnant    while (__len != 0)
42903e519524SHoward Hinnant    {
429104695a75SLouis Dionne        difference_type __l2 = _VSTD::__half_positive(__len);
42923e519524SHoward Hinnant        _ForwardIterator __m = __first;
4293ce48a113SHoward Hinnant        _VSTD::advance(__m, __l2);
4294e4383379SHoward Hinnant        if (__comp(*__m, __value_))
42953e519524SHoward Hinnant        {
42963e519524SHoward Hinnant            __first = ++__m;
42973e519524SHoward Hinnant            __len -= __l2 + 1;
42983e519524SHoward Hinnant        }
42993e519524SHoward Hinnant        else
43003e519524SHoward Hinnant            __len = __l2;
43013e519524SHoward Hinnant    }
43023e519524SHoward Hinnant    return __first;
43033e519524SHoward Hinnant}
43043e519524SHoward Hinnant
43053e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Tp, class _Compare>
43061362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
43071362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
43083e519524SHoward Hinnant_ForwardIterator
4309e4383379SHoward Hinnantlower_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
43103e519524SHoward Hinnant{
43113e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
43121968804aSArthur O'Dwyer    return _VSTD::__lower_bound<_Comp_ref>(__first, __last, __value_, __comp);
43133e519524SHoward Hinnant}
43143e519524SHoward Hinnant
43153e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Tp>
43161362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
43171362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
43183e519524SHoward Hinnant_ForwardIterator
4319e4383379SHoward Hinnantlower_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_)
43203e519524SHoward Hinnant{
4321e4383379SHoward Hinnant    return _VSTD::lower_bound(__first, __last, __value_,
43223e519524SHoward Hinnant                             __less<typename iterator_traits<_ForwardIterator>::value_type, _Tp>());
43233e519524SHoward Hinnant}
43243e519524SHoward Hinnant
43253e519524SHoward Hinnant// upper_bound
43263e519524SHoward Hinnant
43273e519524SHoward Hinnanttemplate <class _Compare, class _ForwardIterator, class _Tp>
4328d57c03ddSMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
4329e4383379SHoward Hinnant__upper_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
43303e519524SHoward Hinnant{
43313e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator>::difference_type difference_type;
4332ce48a113SHoward Hinnant    difference_type __len = _VSTD::distance(__first, __last);
43333e519524SHoward Hinnant    while (__len != 0)
43343e519524SHoward Hinnant    {
433504695a75SLouis Dionne        difference_type __l2 = _VSTD::__half_positive(__len);
43363e519524SHoward Hinnant        _ForwardIterator __m = __first;
4337ce48a113SHoward Hinnant        _VSTD::advance(__m, __l2);
4338e4383379SHoward Hinnant        if (__comp(__value_, *__m))
43393e519524SHoward Hinnant            __len = __l2;
43403e519524SHoward Hinnant        else
43413e519524SHoward Hinnant        {
43423e519524SHoward Hinnant            __first = ++__m;
43433e519524SHoward Hinnant            __len -= __l2 + 1;
43443e519524SHoward Hinnant        }
43453e519524SHoward Hinnant    }
43463e519524SHoward Hinnant    return __first;
43473e519524SHoward Hinnant}
43483e519524SHoward Hinnant
43493e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Tp, class _Compare>
43501362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
43511362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
43523e519524SHoward Hinnant_ForwardIterator
4353e4383379SHoward Hinnantupper_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
43543e519524SHoward Hinnant{
43553e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
43561968804aSArthur O'Dwyer    return _VSTD::__upper_bound<_Comp_ref>(__first, __last, __value_, __comp);
43573e519524SHoward Hinnant}
43583e519524SHoward Hinnant
43593e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Tp>
43601362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
43611362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
43623e519524SHoward Hinnant_ForwardIterator
4363e4383379SHoward Hinnantupper_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_)
43643e519524SHoward Hinnant{
4365e4383379SHoward Hinnant    return _VSTD::upper_bound(__first, __last, __value_,
43663e519524SHoward Hinnant                             __less<_Tp, typename iterator_traits<_ForwardIterator>::value_type>());
43673e519524SHoward Hinnant}
43683e519524SHoward Hinnant
43693e519524SHoward Hinnant// equal_range
43703e519524SHoward Hinnant
43713e519524SHoward Hinnanttemplate <class _Compare, class _ForwardIterator, class _Tp>
4372d57c03ddSMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 pair<_ForwardIterator, _ForwardIterator>
4373e4383379SHoward Hinnant__equal_range(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
43743e519524SHoward Hinnant{
43753e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator>::difference_type difference_type;
4376ce48a113SHoward Hinnant    difference_type __len = _VSTD::distance(__first, __last);
43773e519524SHoward Hinnant    while (__len != 0)
43783e519524SHoward Hinnant    {
437904695a75SLouis Dionne        difference_type __l2 = _VSTD::__half_positive(__len);
43803e519524SHoward Hinnant        _ForwardIterator __m = __first;
4381ce48a113SHoward Hinnant        _VSTD::advance(__m, __l2);
4382e4383379SHoward Hinnant        if (__comp(*__m, __value_))
43833e519524SHoward Hinnant        {
43843e519524SHoward Hinnant            __first = ++__m;
43853e519524SHoward Hinnant            __len -= __l2 + 1;
43863e519524SHoward Hinnant        }
4387e4383379SHoward Hinnant        else if (__comp(__value_, *__m))
43883e519524SHoward Hinnant        {
43893e519524SHoward Hinnant            __last = __m;
43903e519524SHoward Hinnant            __len = __l2;
43913e519524SHoward Hinnant        }
43923e519524SHoward Hinnant        else
43933e519524SHoward Hinnant        {
43943e519524SHoward Hinnant            _ForwardIterator __mp1 = __m;
43953e519524SHoward Hinnant            return pair<_ForwardIterator, _ForwardIterator>
43963e519524SHoward Hinnant                   (
43971968804aSArthur O'Dwyer                      _VSTD::__lower_bound<_Compare>(__first, __m, __value_, __comp),
43981968804aSArthur O'Dwyer                      _VSTD::__upper_bound<_Compare>(++__mp1, __last, __value_, __comp)
43993e519524SHoward Hinnant                   );
44003e519524SHoward Hinnant        }
44013e519524SHoward Hinnant    }
44023e519524SHoward Hinnant    return pair<_ForwardIterator, _ForwardIterator>(__first, __first);
44033e519524SHoward Hinnant}
44043e519524SHoward Hinnant
44053e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Tp, class _Compare>
44061362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
44071362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
44083e519524SHoward Hinnantpair<_ForwardIterator, _ForwardIterator>
4409e4383379SHoward Hinnantequal_range(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
44103e519524SHoward Hinnant{
4411aa1cad15SEric Fiselier    typedef typename __comp_ref_type<_Compare>::type _Comp_ref;
44121968804aSArthur O'Dwyer    return _VSTD::__equal_range<_Comp_ref>(__first, __last, __value_, __comp);
44133e519524SHoward Hinnant}
44143e519524SHoward Hinnant
44153e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Tp>
44161362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
44171362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
44183e519524SHoward Hinnantpair<_ForwardIterator, _ForwardIterator>
4419e4383379SHoward Hinnantequal_range(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_)
44203e519524SHoward Hinnant{
4421e4383379SHoward Hinnant    return _VSTD::equal_range(__first, __last, __value_,
44223e519524SHoward Hinnant                             __less<typename iterator_traits<_ForwardIterator>::value_type, _Tp>());
44233e519524SHoward Hinnant}
44243e519524SHoward Hinnant
44253e519524SHoward Hinnant// binary_search
44263e519524SHoward Hinnant
44273e519524SHoward Hinnanttemplate <class _Compare, class _ForwardIterator, class _Tp>
4428d57c03ddSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
44293e519524SHoward Hinnantbool
4430e4383379SHoward Hinnant__binary_search(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
44313e519524SHoward Hinnant{
44321968804aSArthur O'Dwyer    __first = _VSTD::__lower_bound<_Compare>(__first, __last, __value_, __comp);
4433e4383379SHoward Hinnant    return __first != __last && !__comp(__value_, *__first);
44343e519524SHoward Hinnant}
44353e519524SHoward Hinnant
44363e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Tp, class _Compare>
44371362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
44381362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
44393e519524SHoward Hinnantbool
4440e4383379SHoward Hinnantbinary_search(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
44413e519524SHoward Hinnant{
4442aa1cad15SEric Fiselier    typedef typename __comp_ref_type<_Compare>::type _Comp_ref;
44431968804aSArthur O'Dwyer    return _VSTD::__binary_search<_Comp_ref>(__first, __last, __value_, __comp);
44443e519524SHoward Hinnant}
44453e519524SHoward Hinnant
44463e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Tp>
44471362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
44481362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
44493e519524SHoward Hinnantbool
4450e4383379SHoward Hinnantbinary_search(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_)
44513e519524SHoward Hinnant{
4452e4383379SHoward Hinnant    return _VSTD::binary_search(__first, __last, __value_,
44533e519524SHoward Hinnant                             __less<typename iterator_traits<_ForwardIterator>::value_type, _Tp>());
44543e519524SHoward Hinnant}
44553e519524SHoward Hinnant
44563e519524SHoward Hinnant// merge
44573e519524SHoward Hinnant
44583e519524SHoward Hinnanttemplate <class _Compare, class _InputIterator1, class _InputIterator2, class _OutputIterator>
4459b552a302SNicholas-Baron_LIBCPP_CONSTEXPR_AFTER_CXX17
44603e519524SHoward Hinnant_OutputIterator
44613e519524SHoward Hinnant__merge(_InputIterator1 __first1, _InputIterator1 __last1,
44623e519524SHoward Hinnant        _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
44633e519524SHoward Hinnant{
44643e519524SHoward Hinnant    for (; __first1 != __last1; ++__result)
44653e519524SHoward Hinnant    {
44663e519524SHoward Hinnant        if (__first2 == __last2)
4467ce48a113SHoward Hinnant            return _VSTD::copy(__first1, __last1, __result);
44683e519524SHoward Hinnant        if (__comp(*__first2, *__first1))
44693e519524SHoward Hinnant        {
44703e519524SHoward Hinnant            *__result = *__first2;
44713e519524SHoward Hinnant            ++__first2;
44723e519524SHoward Hinnant        }
44733e519524SHoward Hinnant        else
44743e519524SHoward Hinnant        {
44753e519524SHoward Hinnant            *__result = *__first1;
44763e519524SHoward Hinnant            ++__first1;
44773e519524SHoward Hinnant        }
44783e519524SHoward Hinnant    }
4479ce48a113SHoward Hinnant    return _VSTD::copy(__first2, __last2, __result);
44803e519524SHoward Hinnant}
44813e519524SHoward Hinnant
44823e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
4483b552a302SNicholas-Baroninline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
44843e519524SHoward Hinnant_OutputIterator
44853e519524SHoward Hinnantmerge(_InputIterator1 __first1, _InputIterator1 __last1,
44863e519524SHoward Hinnant      _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
44873e519524SHoward Hinnant{
4488aa1cad15SEric Fiselier    typedef typename __comp_ref_type<_Compare>::type _Comp_ref;
4489ce48a113SHoward Hinnant    return _VSTD::__merge<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __comp);
44903e519524SHoward Hinnant}
44913e519524SHoward Hinnant
44923e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _OutputIterator>
4493b552a302SNicholas-Baroninline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
44943e519524SHoward Hinnant_OutputIterator
44953e519524SHoward Hinnantmerge(_InputIterator1 __first1, _InputIterator1 __last1,
44963e519524SHoward Hinnant      _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result)
44973e519524SHoward Hinnant{
44983e519524SHoward Hinnant    typedef typename iterator_traits<_InputIterator1>::value_type __v1;
44993e519524SHoward Hinnant    typedef typename iterator_traits<_InputIterator2>::value_type __v2;
45004f41779cSMarshall Clow    return _VSTD::merge(__first1, __last1, __first2, __last2, __result, __less<__v1, __v2>());
45013e519524SHoward Hinnant}
45023e519524SHoward Hinnant
45033e519524SHoward Hinnant// inplace_merge
45043e519524SHoward Hinnant
4505adfdae18SMarshall Clowtemplate <class _Compare, class _InputIterator1, class _InputIterator2,
4506adfdae18SMarshall Clow          class _OutputIterator>
4507adfdae18SMarshall Clowvoid __half_inplace_merge(_InputIterator1 __first1, _InputIterator1 __last1,
4508adfdae18SMarshall Clow                          _InputIterator2 __first2, _InputIterator2 __last2,
4509adfdae18SMarshall Clow                          _OutputIterator __result, _Compare __comp)
4510adfdae18SMarshall Clow{
4511adfdae18SMarshall Clow    for (; __first1 != __last1; ++__result)
4512adfdae18SMarshall Clow    {
4513adfdae18SMarshall Clow        if (__first2 == __last2)
4514adfdae18SMarshall Clow        {
4515adfdae18SMarshall Clow            _VSTD::move(__first1, __last1, __result);
4516adfdae18SMarshall Clow            return;
4517adfdae18SMarshall Clow        }
4518adfdae18SMarshall Clow
4519adfdae18SMarshall Clow        if (__comp(*__first2, *__first1))
4520adfdae18SMarshall Clow        {
4521adfdae18SMarshall Clow            *__result = _VSTD::move(*__first2);
4522adfdae18SMarshall Clow            ++__first2;
4523adfdae18SMarshall Clow        }
4524adfdae18SMarshall Clow        else
4525adfdae18SMarshall Clow        {
4526adfdae18SMarshall Clow            *__result = _VSTD::move(*__first1);
4527adfdae18SMarshall Clow            ++__first1;
4528adfdae18SMarshall Clow        }
4529adfdae18SMarshall Clow    }
4530adfdae18SMarshall Clow    // __first2 through __last2 are already in the right spot.
4531adfdae18SMarshall Clow}
4532adfdae18SMarshall Clow
45333e519524SHoward Hinnanttemplate <class _Compare, class _BidirectionalIterator>
45343e519524SHoward Hinnantvoid
45353e519524SHoward Hinnant__buffered_inplace_merge(_BidirectionalIterator __first, _BidirectionalIterator __middle, _BidirectionalIterator __last,
45363e519524SHoward Hinnant                _Compare __comp, typename iterator_traits<_BidirectionalIterator>::difference_type __len1,
45373e519524SHoward Hinnant                                 typename iterator_traits<_BidirectionalIterator>::difference_type __len2,
45383e519524SHoward Hinnant                typename iterator_traits<_BidirectionalIterator>::value_type* __buff)
45393e519524SHoward Hinnant{
45403e519524SHoward Hinnant    typedef typename iterator_traits<_BidirectionalIterator>::value_type value_type;
45413e519524SHoward Hinnant    __destruct_n __d(0);
45423e519524SHoward Hinnant    unique_ptr<value_type, __destruct_n&> __h2(__buff, __d);
45433e519524SHoward Hinnant    if (__len1 <= __len2)
45443e519524SHoward Hinnant    {
45453e519524SHoward Hinnant        value_type* __p = __buff;
4546527a7fdfSBruce Mitchener        for (_BidirectionalIterator __i = __first; __i != __middle; __d.template __incr<value_type>(), (void) ++__i, (void) ++__p)
4547be4c657bSArthur O'Dwyer            ::new ((void*)__p) value_type(_VSTD::move(*__i));
4548eef4bdbbSArthur O'Dwyer        _VSTD::__half_inplace_merge<_Compare>(__buff, __p, __middle, __last, __first, __comp);
45493e519524SHoward Hinnant    }
45503e519524SHoward Hinnant    else
45513e519524SHoward Hinnant    {
45523e519524SHoward Hinnant        value_type* __p = __buff;
4553527a7fdfSBruce Mitchener        for (_BidirectionalIterator __i = __middle; __i != __last; __d.template __incr<value_type>(), (void) ++__i, (void) ++__p)
4554be4c657bSArthur O'Dwyer            ::new ((void*)__p) value_type(_VSTD::move(*__i));
45553e519524SHoward Hinnant        typedef reverse_iterator<_BidirectionalIterator> _RBi;
45563e519524SHoward Hinnant        typedef reverse_iterator<value_type*> _Rv;
4557eef4bdbbSArthur O'Dwyer        typedef __invert<_Compare> _Inverted;
4558eef4bdbbSArthur O'Dwyer        _VSTD::__half_inplace_merge<_Inverted>(_Rv(__p), _Rv(__buff),
4559adfdae18SMarshall Clow                                    _RBi(__middle), _RBi(__first),
4560eef4bdbbSArthur O'Dwyer                                    _RBi(__last), _Inverted(__comp));
45613e519524SHoward Hinnant    }
45623e519524SHoward Hinnant}
45633e519524SHoward Hinnant
45643e519524SHoward Hinnanttemplate <class _Compare, class _BidirectionalIterator>
45653e519524SHoward Hinnantvoid
45663e519524SHoward Hinnant__inplace_merge(_BidirectionalIterator __first, _BidirectionalIterator __middle, _BidirectionalIterator __last,
45673e519524SHoward Hinnant                _Compare __comp, typename iterator_traits<_BidirectionalIterator>::difference_type __len1,
45683e519524SHoward Hinnant                                 typename iterator_traits<_BidirectionalIterator>::difference_type __len2,
45693e519524SHoward Hinnant                typename iterator_traits<_BidirectionalIterator>::value_type* __buff, ptrdiff_t __buff_size)
45703e519524SHoward Hinnant{
45713e519524SHoward Hinnant    typedef typename iterator_traits<_BidirectionalIterator>::difference_type difference_type;
45723e519524SHoward Hinnant    while (true)
45733e519524SHoward Hinnant    {
45743e519524SHoward Hinnant        // if __middle == __last, we're done
45753e519524SHoward Hinnant        if (__len2 == 0)
45763e519524SHoward Hinnant            return;
4577526e0929SMarshall Clow        if (__len1 <= __buff_size || __len2 <= __buff_size)
45781968804aSArthur O'Dwyer            return _VSTD::__buffered_inplace_merge<_Compare>
4579526e0929SMarshall Clow                   (__first, __middle, __last, __comp, __len1, __len2, __buff);
45803e519524SHoward Hinnant        // shrink [__first, __middle) as much as possible (with no moves), returning if it shrinks to 0
4581910285b2SEric Fiselier        for (; true; ++__first, (void) --__len1)
45823e519524SHoward Hinnant        {
45833e519524SHoward Hinnant            if (__len1 == 0)
45843e519524SHoward Hinnant                return;
45853e519524SHoward Hinnant            if (__comp(*__middle, *__first))
45863e519524SHoward Hinnant                break;
45873e519524SHoward Hinnant        }
45883e519524SHoward Hinnant        // __first < __middle < __last
45893e519524SHoward Hinnant        // *__first > *__middle
45903e519524SHoward Hinnant        // partition [__first, __m1) [__m1, __middle) [__middle, __m2) [__m2, __last) such that
45913e519524SHoward Hinnant        //     all elements in:
45923e519524SHoward Hinnant        //         [__first, __m1)  <= [__middle, __m2)
45933e519524SHoward Hinnant        //         [__middle, __m2) <  [__m1, __middle)
45943e519524SHoward Hinnant        //         [__m1, __middle) <= [__m2, __last)
45953e519524SHoward Hinnant        //     and __m1 or __m2 is in the middle of its range
45963e519524SHoward Hinnant        _BidirectionalIterator __m1;  // "median" of [__first, __middle)
45973e519524SHoward Hinnant        _BidirectionalIterator __m2;  // "median" of [__middle, __last)
45983e519524SHoward Hinnant        difference_type __len11;      // distance(__first, __m1)
45993e519524SHoward Hinnant        difference_type __len21;      // distance(__middle, __m2)
46003e519524SHoward Hinnant        // binary search smaller range
46013e519524SHoward Hinnant        if (__len1 < __len2)
46023e519524SHoward Hinnant        {   // __len >= 1, __len2 >= 2
46033e519524SHoward Hinnant            __len21 = __len2 / 2;
46043e519524SHoward Hinnant            __m2 = __middle;
4605ce48a113SHoward Hinnant            _VSTD::advance(__m2, __len21);
46061968804aSArthur O'Dwyer            __m1 = _VSTD::__upper_bound<_Compare>(__first, __middle, *__m2, __comp);
4607ce48a113SHoward Hinnant            __len11 = _VSTD::distance(__first, __m1);
46083e519524SHoward Hinnant        }
46093e519524SHoward Hinnant        else
46103e519524SHoward Hinnant        {
46113e519524SHoward Hinnant            if (__len1 == 1)
46123e519524SHoward Hinnant            {   // __len1 >= __len2 && __len2 > 0, therefore __len2 == 1
46133e519524SHoward Hinnant                // It is known *__first > *__middle
46143e519524SHoward Hinnant                swap(*__first, *__middle);
46153e519524SHoward Hinnant                return;
46163e519524SHoward Hinnant            }
46173e519524SHoward Hinnant            // __len1 >= 2, __len2 >= 1
46183e519524SHoward Hinnant            __len11 = __len1 / 2;
46193e519524SHoward Hinnant            __m1 = __first;
4620ce48a113SHoward Hinnant            _VSTD::advance(__m1, __len11);
46211968804aSArthur O'Dwyer            __m2 = _VSTD::__lower_bound<_Compare>(__middle, __last, *__m1, __comp);
4622ce48a113SHoward Hinnant            __len21 = _VSTD::distance(__middle, __m2);
46233e519524SHoward Hinnant        }
46243e519524SHoward Hinnant        difference_type __len12 = __len1 - __len11;  // distance(__m1, __middle)
46253e519524SHoward Hinnant        difference_type __len22 = __len2 - __len21;  // distance(__m2, __last)
46263e519524SHoward Hinnant        // [__first, __m1) [__m1, __middle) [__middle, __m2) [__m2, __last)
46273e519524SHoward Hinnant        // swap middle two partitions
4628ce48a113SHoward Hinnant        __middle = _VSTD::rotate(__m1, __middle, __m2);
46293e519524SHoward Hinnant        // __len12 and __len21 now have swapped meanings
4630b6f19174SArthur O'Dwyer        // merge smaller range with recursive call and larger with tail recursion elimination
46313e519524SHoward Hinnant        if (__len11 + __len21 < __len12 + __len22)
46323e519524SHoward Hinnant        {
46331968804aSArthur O'Dwyer            _VSTD::__inplace_merge<_Compare>(__first, __m1, __middle, __comp, __len11, __len21, __buff, __buff_size);
46341968804aSArthur O'Dwyer//          _VSTD::__inplace_merge<_Compare>(__middle, __m2, __last, __comp, __len12, __len22, __buff, __buff_size);
46353e519524SHoward Hinnant            __first = __middle;
46363e519524SHoward Hinnant            __middle = __m2;
46373e519524SHoward Hinnant            __len1 = __len12;
46383e519524SHoward Hinnant            __len2 = __len22;
46393e519524SHoward Hinnant        }
46403e519524SHoward Hinnant        else
46413e519524SHoward Hinnant        {
46421968804aSArthur O'Dwyer            _VSTD::__inplace_merge<_Compare>(__middle, __m2, __last, __comp, __len12, __len22, __buff, __buff_size);
46431968804aSArthur O'Dwyer//          _VSTD::__inplace_merge<_Compare>(__first, __m1, __middle, __comp, __len11, __len21, __buff, __buff_size);
46443e519524SHoward Hinnant            __last = __middle;
46453e519524SHoward Hinnant            __middle = __m1;
46463e519524SHoward Hinnant            __len1 = __len11;
46473e519524SHoward Hinnant            __len2 = __len21;
46483e519524SHoward Hinnant        }
46493e519524SHoward Hinnant    }
46503e519524SHoward Hinnant}
46513e519524SHoward Hinnant
46523e519524SHoward Hinnanttemplate <class _BidirectionalIterator, class _Compare>
46533e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
46543e519524SHoward Hinnantvoid
46553e519524SHoward Hinnantinplace_merge(_BidirectionalIterator __first, _BidirectionalIterator __middle, _BidirectionalIterator __last,
46563e519524SHoward Hinnant              _Compare __comp)
46573e519524SHoward Hinnant{
46583e519524SHoward Hinnant    typedef typename iterator_traits<_BidirectionalIterator>::value_type value_type;
46593e519524SHoward Hinnant    typedef typename iterator_traits<_BidirectionalIterator>::difference_type difference_type;
4660ce48a113SHoward Hinnant    difference_type __len1 = _VSTD::distance(__first, __middle);
4661ce48a113SHoward Hinnant    difference_type __len2 = _VSTD::distance(__middle, __last);
4662ce48a113SHoward Hinnant    difference_type __buf_size = _VSTD::min(__len1, __len2);
46630b48cf9aSMarshall Clow    pair<value_type*, ptrdiff_t> __buf = _VSTD::get_temporary_buffer<value_type>(__buf_size);
46640b48cf9aSMarshall Clow    unique_ptr<value_type, __return_temporary_buffer> __h(__buf.first);
4665aa1cad15SEric Fiselier    typedef typename __comp_ref_type<_Compare>::type _Comp_ref;
4666ce48a113SHoward Hinnant    return _VSTD::__inplace_merge<_Comp_ref>(__first, __middle, __last, __comp, __len1, __len2,
46673e519524SHoward Hinnant                                            __buf.first, __buf.second);
46683e519524SHoward Hinnant}
46693e519524SHoward Hinnant
46703e519524SHoward Hinnanttemplate <class _BidirectionalIterator>
46713e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
46723e519524SHoward Hinnantvoid
46733e519524SHoward Hinnantinplace_merge(_BidirectionalIterator __first, _BidirectionalIterator __middle, _BidirectionalIterator __last)
46743e519524SHoward Hinnant{
4675ce48a113SHoward Hinnant    _VSTD::inplace_merge(__first, __middle, __last,
46763e519524SHoward Hinnant                        __less<typename iterator_traits<_BidirectionalIterator>::value_type>());
46773e519524SHoward Hinnant}
46783e519524SHoward Hinnant
46793e519524SHoward Hinnant// stable_sort
46803e519524SHoward Hinnant
46813e519524SHoward Hinnanttemplate <class _Compare, class _InputIterator1, class _InputIterator2>
46823e519524SHoward Hinnantvoid
46833e519524SHoward Hinnant__merge_move_construct(_InputIterator1 __first1, _InputIterator1 __last1,
46843e519524SHoward Hinnant        _InputIterator2 __first2, _InputIterator2 __last2,
46853e519524SHoward Hinnant        typename iterator_traits<_InputIterator1>::value_type* __result, _Compare __comp)
46863e519524SHoward Hinnant{
46873e519524SHoward Hinnant    typedef typename iterator_traits<_InputIterator1>::value_type value_type;
46883e519524SHoward Hinnant    __destruct_n __d(0);
46893e519524SHoward Hinnant    unique_ptr<value_type, __destruct_n&> __h(__result, __d);
46903e519524SHoward Hinnant    for (; true; ++__result)
46913e519524SHoward Hinnant    {
46923e519524SHoward Hinnant        if (__first1 == __last1)
46933e519524SHoward Hinnant        {
4694527a7fdfSBruce Mitchener            for (; __first2 != __last2; ++__first2, ++__result, (void)__d.template __incr<value_type>())
4695be4c657bSArthur O'Dwyer                ::new ((void*)__result) value_type(_VSTD::move(*__first2));
46963e519524SHoward Hinnant            __h.release();
46973e519524SHoward Hinnant            return;
46983e519524SHoward Hinnant        }
46993e519524SHoward Hinnant        if (__first2 == __last2)
47003e519524SHoward Hinnant        {
4701527a7fdfSBruce Mitchener            for (; __first1 != __last1; ++__first1, ++__result, (void)__d.template __incr<value_type>())
4702be4c657bSArthur O'Dwyer                ::new ((void*)__result) value_type(_VSTD::move(*__first1));
47033e519524SHoward Hinnant            __h.release();
47043e519524SHoward Hinnant            return;
47053e519524SHoward Hinnant        }
47063e519524SHoward Hinnant        if (__comp(*__first2, *__first1))
47073e519524SHoward Hinnant        {
4708be4c657bSArthur O'Dwyer            ::new ((void*)__result) value_type(_VSTD::move(*__first2));
4709527a7fdfSBruce Mitchener            __d.template __incr<value_type>();
47103e519524SHoward Hinnant            ++__first2;
47113e519524SHoward Hinnant        }
47123e519524SHoward Hinnant        else
47133e519524SHoward Hinnant        {
4714be4c657bSArthur O'Dwyer            ::new ((void*)__result) value_type(_VSTD::move(*__first1));
4715527a7fdfSBruce Mitchener            __d.template __incr<value_type>();
47163e519524SHoward Hinnant            ++__first1;
47173e519524SHoward Hinnant        }
47183e519524SHoward Hinnant    }
47193e519524SHoward Hinnant}
47203e519524SHoward Hinnant
47213e519524SHoward Hinnanttemplate <class _Compare, class _InputIterator1, class _InputIterator2, class _OutputIterator>
47223e519524SHoward Hinnantvoid
47233e519524SHoward Hinnant__merge_move_assign(_InputIterator1 __first1, _InputIterator1 __last1,
47243e519524SHoward Hinnant        _InputIterator2 __first2, _InputIterator2 __last2,
47253e519524SHoward Hinnant        _OutputIterator __result, _Compare __comp)
47263e519524SHoward Hinnant{
47273e519524SHoward Hinnant    for (; __first1 != __last1; ++__result)
47283e519524SHoward Hinnant    {
47293e519524SHoward Hinnant        if (__first2 == __last2)
47303e519524SHoward Hinnant        {
47317fa68653SMarshall Clow            for (; __first1 != __last1; ++__first1, (void) ++__result)
4732ce48a113SHoward Hinnant                *__result = _VSTD::move(*__first1);
47333e519524SHoward Hinnant            return;
47343e519524SHoward Hinnant        }
47353e519524SHoward Hinnant        if (__comp(*__first2, *__first1))
47363e519524SHoward Hinnant        {
4737ce48a113SHoward Hinnant            *__result = _VSTD::move(*__first2);
47383e519524SHoward Hinnant            ++__first2;
47393e519524SHoward Hinnant        }
47403e519524SHoward Hinnant        else
47413e519524SHoward Hinnant        {
4742ce48a113SHoward Hinnant            *__result = _VSTD::move(*__first1);
47433e519524SHoward Hinnant            ++__first1;
47443e519524SHoward Hinnant        }
47453e519524SHoward Hinnant    }
47467fa68653SMarshall Clow    for (; __first2 != __last2; ++__first2, (void) ++__result)
4747ce48a113SHoward Hinnant        *__result = _VSTD::move(*__first2);
47483e519524SHoward Hinnant}
47493e519524SHoward Hinnant
47503e519524SHoward Hinnanttemplate <class _Compare, class _RandomAccessIterator>
47513e519524SHoward Hinnantvoid
47523e519524SHoward Hinnant__stable_sort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp,
47533e519524SHoward Hinnant              typename iterator_traits<_RandomAccessIterator>::difference_type __len,
47543e519524SHoward Hinnant              typename iterator_traits<_RandomAccessIterator>::value_type* __buff, ptrdiff_t __buff_size);
47553e519524SHoward Hinnant
47563e519524SHoward Hinnanttemplate <class _Compare, class _RandomAccessIterator>
47573e519524SHoward Hinnantvoid
47583e519524SHoward Hinnant__stable_sort_move(_RandomAccessIterator __first1, _RandomAccessIterator __last1, _Compare __comp,
47593e519524SHoward Hinnant                   typename iterator_traits<_RandomAccessIterator>::difference_type __len,
47603e519524SHoward Hinnant                   typename iterator_traits<_RandomAccessIterator>::value_type* __first2)
47613e519524SHoward Hinnant{
47623e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
47633e519524SHoward Hinnant    switch (__len)
47643e519524SHoward Hinnant    {
47653e519524SHoward Hinnant    case 0:
47663e519524SHoward Hinnant        return;
47673e519524SHoward Hinnant    case 1:
4768be4c657bSArthur O'Dwyer        ::new ((void*)__first2) value_type(_VSTD::move(*__first1));
47693e519524SHoward Hinnant        return;
47703e519524SHoward Hinnant    case 2:
47713e519524SHoward Hinnant        __destruct_n __d(0);
47723e519524SHoward Hinnant        unique_ptr<value_type, __destruct_n&> __h2(__first2, __d);
47733e519524SHoward Hinnant        if (__comp(*--__last1, *__first1))
47743e519524SHoward Hinnant        {
4775be4c657bSArthur O'Dwyer            ::new ((void*)__first2) value_type(_VSTD::move(*__last1));
4776527a7fdfSBruce Mitchener            __d.template __incr<value_type>();
47773e519524SHoward Hinnant            ++__first2;
4778be4c657bSArthur O'Dwyer            ::new ((void*)__first2) value_type(_VSTD::move(*__first1));
47793e519524SHoward Hinnant        }
47803e519524SHoward Hinnant        else
47813e519524SHoward Hinnant        {
4782be4c657bSArthur O'Dwyer            ::new ((void*)__first2) value_type(_VSTD::move(*__first1));
4783527a7fdfSBruce Mitchener            __d.template __incr<value_type>();
47843e519524SHoward Hinnant            ++__first2;
4785be4c657bSArthur O'Dwyer            ::new ((void*)__first2) value_type(_VSTD::move(*__last1));
47863e519524SHoward Hinnant        }
47873e519524SHoward Hinnant        __h2.release();
47883e519524SHoward Hinnant        return;
47893e519524SHoward Hinnant    }
47903e519524SHoward Hinnant    if (__len <= 8)
47913e519524SHoward Hinnant    {
47921968804aSArthur O'Dwyer        _VSTD::__insertion_sort_move<_Compare>(__first1, __last1, __first2, __comp);
47933e519524SHoward Hinnant        return;
47943e519524SHoward Hinnant    }
47953e519524SHoward Hinnant    typename iterator_traits<_RandomAccessIterator>::difference_type __l2 = __len / 2;
47963e519524SHoward Hinnant    _RandomAccessIterator __m = __first1 + __l2;
47971968804aSArthur O'Dwyer    _VSTD::__stable_sort<_Compare>(__first1, __m, __comp, __l2, __first2, __l2);
47981968804aSArthur O'Dwyer    _VSTD::__stable_sort<_Compare>(__m, __last1, __comp, __len - __l2, __first2 + __l2, __len - __l2);
47991968804aSArthur O'Dwyer    _VSTD::__merge_move_construct<_Compare>(__first1, __m, __m, __last1, __first2, __comp);
48003e519524SHoward Hinnant}
48013e519524SHoward Hinnant
48023e519524SHoward Hinnanttemplate <class _Tp>
48033e519524SHoward Hinnantstruct __stable_sort_switch
48043e519524SHoward Hinnant{
4805ca740483SHoward Hinnant    static const unsigned value = 128*is_trivially_copy_assignable<_Tp>::value;
48063e519524SHoward Hinnant};
48073e519524SHoward Hinnant
48083e519524SHoward Hinnanttemplate <class _Compare, class _RandomAccessIterator>
48093e519524SHoward Hinnantvoid
48103e519524SHoward Hinnant__stable_sort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp,
48113e519524SHoward Hinnant              typename iterator_traits<_RandomAccessIterator>::difference_type __len,
48123e519524SHoward Hinnant              typename iterator_traits<_RandomAccessIterator>::value_type* __buff, ptrdiff_t __buff_size)
48133e519524SHoward Hinnant{
48143e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
48153e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
48163e519524SHoward Hinnant    switch (__len)
48173e519524SHoward Hinnant    {
48183e519524SHoward Hinnant    case 0:
48193e519524SHoward Hinnant    case 1:
48203e519524SHoward Hinnant        return;
48213e519524SHoward Hinnant    case 2:
48223e519524SHoward Hinnant        if (__comp(*--__last, *__first))
48233e519524SHoward Hinnant            swap(*__first, *__last);
48243e519524SHoward Hinnant        return;
48253e519524SHoward Hinnant    }
48263e519524SHoward Hinnant    if (__len <= static_cast<difference_type>(__stable_sort_switch<value_type>::value))
48273e519524SHoward Hinnant    {
48281968804aSArthur O'Dwyer        _VSTD::__insertion_sort<_Compare>(__first, __last, __comp);
48293e519524SHoward Hinnant        return;
48303e519524SHoward Hinnant    }
48313e519524SHoward Hinnant    typename iterator_traits<_RandomAccessIterator>::difference_type __l2 = __len / 2;
48323e519524SHoward Hinnant    _RandomAccessIterator __m = __first + __l2;
48333e519524SHoward Hinnant    if (__len <= __buff_size)
48343e519524SHoward Hinnant    {
48353e519524SHoward Hinnant        __destruct_n __d(0);
48363e519524SHoward Hinnant        unique_ptr<value_type, __destruct_n&> __h2(__buff, __d);
48371968804aSArthur O'Dwyer        _VSTD::__stable_sort_move<_Compare>(__first, __m, __comp, __l2, __buff);
4838527a7fdfSBruce Mitchener        __d.__set(__l2, (value_type*)nullptr);
48391968804aSArthur O'Dwyer        _VSTD::__stable_sort_move<_Compare>(__m, __last, __comp, __len - __l2, __buff + __l2);
4840527a7fdfSBruce Mitchener        __d.__set(__len, (value_type*)nullptr);
48411968804aSArthur O'Dwyer        _VSTD::__merge_move_assign<_Compare>(__buff, __buff + __l2, __buff + __l2, __buff + __len, __first, __comp);
48421968804aSArthur O'Dwyer//         _VSTD::__merge<_Compare>(move_iterator<value_type*>(__buff),
48433e519524SHoward Hinnant//                                  move_iterator<value_type*>(__buff + __l2),
48443e519524SHoward Hinnant//                                  move_iterator<_RandomAccessIterator>(__buff + __l2),
48453e519524SHoward Hinnant//                                  move_iterator<_RandomAccessIterator>(__buff + __len),
48463e519524SHoward Hinnant//                                  __first, __comp);
48473e519524SHoward Hinnant        return;
48483e519524SHoward Hinnant    }
48491968804aSArthur O'Dwyer    _VSTD::__stable_sort<_Compare>(__first, __m, __comp, __l2, __buff, __buff_size);
48501968804aSArthur O'Dwyer    _VSTD::__stable_sort<_Compare>(__m, __last, __comp, __len - __l2, __buff, __buff_size);
48511968804aSArthur O'Dwyer    _VSTD::__inplace_merge<_Compare>(__first, __m, __last, __comp, __l2, __len - __l2, __buff, __buff_size);
48523e519524SHoward Hinnant}
48533e519524SHoward Hinnant
48543e519524SHoward Hinnanttemplate <class _RandomAccessIterator, class _Compare>
48553e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
48563e519524SHoward Hinnantvoid
48573e519524SHoward Hinnantstable_sort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
48583e519524SHoward Hinnant{
48593e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
48603e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
48613e519524SHoward Hinnant    difference_type __len = __last - __first;
48623e519524SHoward Hinnant    pair<value_type*, ptrdiff_t> __buf(0, 0);
48633e519524SHoward Hinnant    unique_ptr<value_type, __return_temporary_buffer> __h;
48643e519524SHoward Hinnant    if (__len > static_cast<difference_type>(__stable_sort_switch<value_type>::value))
48653e519524SHoward Hinnant    {
4866ce48a113SHoward Hinnant        __buf = _VSTD::get_temporary_buffer<value_type>(__len);
48673e519524SHoward Hinnant        __h.reset(__buf.first);
48683e519524SHoward Hinnant    }
4869aa1cad15SEric Fiselier    typedef typename __comp_ref_type<_Compare>::type _Comp_ref;
48701968804aSArthur O'Dwyer    _VSTD::__stable_sort<_Comp_ref>(__first, __last, __comp, __len, __buf.first, __buf.second);
48713e519524SHoward Hinnant}
48723e519524SHoward Hinnant
48733e519524SHoward Hinnanttemplate <class _RandomAccessIterator>
48743e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
48753e519524SHoward Hinnantvoid
48763e519524SHoward Hinnantstable_sort(_RandomAccessIterator __first, _RandomAccessIterator __last)
48773e519524SHoward Hinnant{
4878ce48a113SHoward Hinnant    _VSTD::stable_sort(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
48793e519524SHoward Hinnant}
48803e519524SHoward Hinnant
48813e519524SHoward Hinnant// is_heap_until
48823e519524SHoward Hinnant
48833e519524SHoward Hinnanttemplate <class _RandomAccessIterator, class _Compare>
48841362d7efSNico Weber_LIBCPP_NODISCARD_EXT _LIBCPP_CONSTEXPR_AFTER_CXX17 _RandomAccessIterator
48853e519524SHoward Hinnantis_heap_until(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
48863e519524SHoward Hinnant{
4887ce48a113SHoward Hinnant    typedef typename _VSTD::iterator_traits<_RandomAccessIterator>::difference_type difference_type;
48883e519524SHoward Hinnant    difference_type __len = __last - __first;
48893e519524SHoward Hinnant    difference_type __p = 0;
48903e519524SHoward Hinnant    difference_type __c = 1;
48913e519524SHoward Hinnant    _RandomAccessIterator __pp = __first;
48923e519524SHoward Hinnant    while (__c < __len)
48933e519524SHoward Hinnant    {
48943e519524SHoward Hinnant        _RandomAccessIterator __cp = __first + __c;
48953e519524SHoward Hinnant        if (__comp(*__pp, *__cp))
48963e519524SHoward Hinnant            return __cp;
48973e519524SHoward Hinnant        ++__c;
48983e519524SHoward Hinnant        ++__cp;
48993e519524SHoward Hinnant        if (__c == __len)
49003e519524SHoward Hinnant            return __last;
49013e519524SHoward Hinnant        if (__comp(*__pp, *__cp))
49023e519524SHoward Hinnant            return __cp;
49033e519524SHoward Hinnant        ++__p;
49043e519524SHoward Hinnant        ++__pp;
49053e519524SHoward Hinnant        __c = 2 * __p + 1;
49063e519524SHoward Hinnant    }
49073e519524SHoward Hinnant    return __last;
49083e519524SHoward Hinnant}
49093e519524SHoward Hinnant
49103e519524SHoward Hinnanttemplate<class _RandomAccessIterator>
49111362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
49121362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
49133e519524SHoward Hinnant_RandomAccessIterator
49143e519524SHoward Hinnantis_heap_until(_RandomAccessIterator __first, _RandomAccessIterator __last)
49153e519524SHoward Hinnant{
4916ce48a113SHoward Hinnant    return _VSTD::is_heap_until(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
49173e519524SHoward Hinnant}
49183e519524SHoward Hinnant
49193e519524SHoward Hinnant// is_heap
49203e519524SHoward Hinnant
49213e519524SHoward Hinnanttemplate <class _RandomAccessIterator, class _Compare>
49221362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
49231362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
49243e519524SHoward Hinnantbool
49253e519524SHoward Hinnantis_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
49263e519524SHoward Hinnant{
4927ce48a113SHoward Hinnant    return _VSTD::is_heap_until(__first, __last, __comp) == __last;
49283e519524SHoward Hinnant}
49293e519524SHoward Hinnant
49303e519524SHoward Hinnanttemplate<class _RandomAccessIterator>
49311362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
49321362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
49333e519524SHoward Hinnantbool
49343e519524SHoward Hinnantis_heap(_RandomAccessIterator __first, _RandomAccessIterator __last)
49353e519524SHoward Hinnant{
4936ce48a113SHoward Hinnant    return _VSTD::is_heap(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
49373e519524SHoward Hinnant}
49383e519524SHoward Hinnant
49393e519524SHoward Hinnant// push_heap
49403e519524SHoward Hinnant
49413e519524SHoward Hinnanttemplate <class _Compare, class _RandomAccessIterator>
49425386aa26SArthur O'Dwyer_LIBCPP_CONSTEXPR_AFTER_CXX11 void
49438b512602SDavid Majnemer__sift_up(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp,
49443e519524SHoward Hinnant          typename iterator_traits<_RandomAccessIterator>::difference_type __len)
49453e519524SHoward Hinnant{
49463e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
49473e519524SHoward Hinnant    if (__len > 1)
49483e519524SHoward Hinnant    {
49493e519524SHoward Hinnant        __len = (__len - 2) / 2;
49503e519524SHoward Hinnant        _RandomAccessIterator __ptr = __first + __len;
49513e519524SHoward Hinnant        if (__comp(*__ptr, *--__last))
49523e519524SHoward Hinnant        {
4953ce48a113SHoward Hinnant            value_type __t(_VSTD::move(*__last));
49543e519524SHoward Hinnant            do
49553e519524SHoward Hinnant            {
4956ce48a113SHoward Hinnant                *__last = _VSTD::move(*__ptr);
49573e519524SHoward Hinnant                __last = __ptr;
49583e519524SHoward Hinnant                if (__len == 0)
49593e519524SHoward Hinnant                    break;
49603e519524SHoward Hinnant                __len = (__len - 1) / 2;
49613e519524SHoward Hinnant                __ptr = __first + __len;
49623e519524SHoward Hinnant            } while (__comp(*__ptr, __t));
4963ce48a113SHoward Hinnant            *__last = _VSTD::move(__t);
49643e519524SHoward Hinnant        }
49653e519524SHoward Hinnant    }
49663e519524SHoward Hinnant}
49673e519524SHoward Hinnant
49683e519524SHoward Hinnanttemplate <class _RandomAccessIterator, class _Compare>
49695386aa26SArthur O'Dwyerinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
49703e519524SHoward Hinnantvoid
49713e519524SHoward Hinnantpush_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
49723e519524SHoward Hinnant{
4973aa1cad15SEric Fiselier    typedef typename __comp_ref_type<_Compare>::type _Comp_ref;
49741968804aSArthur O'Dwyer    _VSTD::__sift_up<_Comp_ref>(__first, __last, __comp, __last - __first);
49753e519524SHoward Hinnant}
49763e519524SHoward Hinnant
49773e519524SHoward Hinnanttemplate <class _RandomAccessIterator>
49785386aa26SArthur O'Dwyerinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
49793e519524SHoward Hinnantvoid
49803e519524SHoward Hinnantpush_heap(_RandomAccessIterator __first, _RandomAccessIterator __last)
49813e519524SHoward Hinnant{
4982ce48a113SHoward Hinnant    _VSTD::push_heap(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
49833e519524SHoward Hinnant}
49843e519524SHoward Hinnant
49853e519524SHoward Hinnant// pop_heap
49863e519524SHoward Hinnant
49873e519524SHoward Hinnanttemplate <class _Compare, class _RandomAccessIterator>
49885386aa26SArthur O'Dwyer_LIBCPP_CONSTEXPR_AFTER_CXX11 void
4989fd838227SEric Fiselier__sift_down(_RandomAccessIterator __first, _RandomAccessIterator /*__last*/,
4990fd838227SEric Fiselier            _Compare __comp,
49918b512602SDavid Majnemer            typename iterator_traits<_RandomAccessIterator>::difference_type __len,
49928b512602SDavid Majnemer            _RandomAccessIterator __start)
49938b512602SDavid Majnemer{
49948b512602SDavid Majnemer    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
49958b512602SDavid Majnemer    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
49968b512602SDavid Majnemer    // left-child of __start is at 2 * __start + 1
49978b512602SDavid Majnemer    // right-child of __start is at 2 * __start + 2
49988b512602SDavid Majnemer    difference_type __child = __start - __first;
49998b512602SDavid Majnemer
50008b512602SDavid Majnemer    if (__len < 2 || (__len - 2) / 2 < __child)
50018b512602SDavid Majnemer        return;
50028b512602SDavid Majnemer
50038b512602SDavid Majnemer    __child = 2 * __child + 1;
50048b512602SDavid Majnemer    _RandomAccessIterator __child_i = __first + __child;
50058b512602SDavid Majnemer
50068b512602SDavid Majnemer    if ((__child + 1) < __len && __comp(*__child_i, *(__child_i + 1))) {
50078b512602SDavid Majnemer        // right-child exists and is greater than left-child
50088b512602SDavid Majnemer        ++__child_i;
50098b512602SDavid Majnemer        ++__child;
50108b512602SDavid Majnemer    }
50118b512602SDavid Majnemer
50128b512602SDavid Majnemer    // check if we are in heap-order
50138b512602SDavid Majnemer    if (__comp(*__child_i, *__start))
50148b512602SDavid Majnemer        // we are, __start is larger than it's largest child
50158b512602SDavid Majnemer        return;
50168b512602SDavid Majnemer
50178b512602SDavid Majnemer    value_type __top(_VSTD::move(*__start));
50188b512602SDavid Majnemer    do
50198b512602SDavid Majnemer    {
50205386aa26SArthur O'Dwyer        // we are not in heap-order, swap the parent with its largest child
50218b512602SDavid Majnemer        *__start = _VSTD::move(*__child_i);
50228b512602SDavid Majnemer        __start = __child_i;
50238b512602SDavid Majnemer
50248b512602SDavid Majnemer        if ((__len - 2) / 2 < __child)
50258b512602SDavid Majnemer            break;
50268b512602SDavid Majnemer
50278b512602SDavid Majnemer        // recompute the child based off of the updated parent
50288b512602SDavid Majnemer        __child = 2 * __child + 1;
50298b512602SDavid Majnemer        __child_i = __first + __child;
50308b512602SDavid Majnemer
50318b512602SDavid Majnemer        if ((__child + 1) < __len && __comp(*__child_i, *(__child_i + 1))) {
50328b512602SDavid Majnemer            // right-child exists and is greater than left-child
50338b512602SDavid Majnemer            ++__child_i;
50348b512602SDavid Majnemer            ++__child;
50358b512602SDavid Majnemer        }
50368b512602SDavid Majnemer
50378b512602SDavid Majnemer        // check if we are in heap-order
50388b512602SDavid Majnemer    } while (!__comp(*__child_i, __top));
50398b512602SDavid Majnemer    *__start = _VSTD::move(__top);
50408b512602SDavid Majnemer}
50418b512602SDavid Majnemer
50428b512602SDavid Majnemertemplate <class _Compare, class _RandomAccessIterator>
50435386aa26SArthur O'Dwyerinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
50443e519524SHoward Hinnantvoid
50453e519524SHoward Hinnant__pop_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp,
50463e519524SHoward Hinnant           typename iterator_traits<_RandomAccessIterator>::difference_type __len)
50473e519524SHoward Hinnant{
50483e519524SHoward Hinnant    if (__len > 1)
50493e519524SHoward Hinnant    {
50503e519524SHoward Hinnant        swap(*__first, *--__last);
50511968804aSArthur O'Dwyer        _VSTD::__sift_down<_Compare>(__first, __last, __comp, __len - 1, __first);
50523e519524SHoward Hinnant    }
50533e519524SHoward Hinnant}
50543e519524SHoward Hinnant
50553e519524SHoward Hinnanttemplate <class _RandomAccessIterator, class _Compare>
50565386aa26SArthur O'Dwyerinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
50573e519524SHoward Hinnantvoid
50583e519524SHoward Hinnantpop_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
50593e519524SHoward Hinnant{
5060aa1cad15SEric Fiselier    typedef typename __comp_ref_type<_Compare>::type _Comp_ref;
50611968804aSArthur O'Dwyer    _VSTD::__pop_heap<_Comp_ref>(__first, __last, __comp, __last - __first);
50623e519524SHoward Hinnant}
50633e519524SHoward Hinnant
50643e519524SHoward Hinnanttemplate <class _RandomAccessIterator>
50655386aa26SArthur O'Dwyerinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
50663e519524SHoward Hinnantvoid
50673e519524SHoward Hinnantpop_heap(_RandomAccessIterator __first, _RandomAccessIterator __last)
50683e519524SHoward Hinnant{
5069ce48a113SHoward Hinnant    _VSTD::pop_heap(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
50703e519524SHoward Hinnant}
50713e519524SHoward Hinnant
50723e519524SHoward Hinnant// make_heap
50733e519524SHoward Hinnant
50743e519524SHoward Hinnanttemplate <class _Compare, class _RandomAccessIterator>
50755386aa26SArthur O'Dwyer_LIBCPP_CONSTEXPR_AFTER_CXX11 void
50763e519524SHoward Hinnant__make_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
50773e519524SHoward Hinnant{
50783e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
50793e519524SHoward Hinnant    difference_type __n = __last - __first;
50803e519524SHoward Hinnant    if (__n > 1)
50813e519524SHoward Hinnant    {
50828b512602SDavid Majnemer        // start from the first parent, there is no need to consider children
50838b512602SDavid Majnemer        for (difference_type __start = (__n - 2) / 2; __start >= 0; --__start)
50848b512602SDavid Majnemer        {
50851968804aSArthur O'Dwyer            _VSTD::__sift_down<_Compare>(__first, __last, __comp, __n, __first + __start);
50868b512602SDavid Majnemer        }
50873e519524SHoward Hinnant    }
50883e519524SHoward Hinnant}
50893e519524SHoward Hinnant
50903e519524SHoward Hinnanttemplate <class _RandomAccessIterator, class _Compare>
50915386aa26SArthur O'Dwyerinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
50923e519524SHoward Hinnantvoid
50933e519524SHoward Hinnantmake_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
50943e519524SHoward Hinnant{
5095aa1cad15SEric Fiselier    typedef typename __comp_ref_type<_Compare>::type _Comp_ref;
50961968804aSArthur O'Dwyer    _VSTD::__make_heap<_Comp_ref>(__first, __last, __comp);
50973e519524SHoward Hinnant}
50983e519524SHoward Hinnant
50993e519524SHoward Hinnanttemplate <class _RandomAccessIterator>
51005386aa26SArthur O'Dwyerinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
51013e519524SHoward Hinnantvoid
51023e519524SHoward Hinnantmake_heap(_RandomAccessIterator __first, _RandomAccessIterator __last)
51033e519524SHoward Hinnant{
5104ce48a113SHoward Hinnant    _VSTD::make_heap(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
51053e519524SHoward Hinnant}
51063e519524SHoward Hinnant
51073e519524SHoward Hinnant// sort_heap
51083e519524SHoward Hinnant
51093e519524SHoward Hinnanttemplate <class _Compare, class _RandomAccessIterator>
51105386aa26SArthur O'Dwyer_LIBCPP_CONSTEXPR_AFTER_CXX17 void
51113e519524SHoward Hinnant__sort_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
51123e519524SHoward Hinnant{
51133e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
51147fa68653SMarshall Clow    for (difference_type __n = __last - __first; __n > 1; --__last, (void) --__n)
51151968804aSArthur O'Dwyer        _VSTD::__pop_heap<_Compare>(__first, __last, __comp, __n);
51163e519524SHoward Hinnant}
51173e519524SHoward Hinnant
51183e519524SHoward Hinnanttemplate <class _RandomAccessIterator, class _Compare>
51195386aa26SArthur O'Dwyerinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
51203e519524SHoward Hinnantvoid
51213e519524SHoward Hinnantsort_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
51223e519524SHoward Hinnant{
5123aa1cad15SEric Fiselier    typedef typename __comp_ref_type<_Compare>::type _Comp_ref;
51241968804aSArthur O'Dwyer    _VSTD::__sort_heap<_Comp_ref>(__first, __last, __comp);
51253e519524SHoward Hinnant}
51263e519524SHoward Hinnant
51273e519524SHoward Hinnanttemplate <class _RandomAccessIterator>
51285386aa26SArthur O'Dwyerinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
51293e519524SHoward Hinnantvoid
51303e519524SHoward Hinnantsort_heap(_RandomAccessIterator __first, _RandomAccessIterator __last)
51313e519524SHoward Hinnant{
5132ce48a113SHoward Hinnant    _VSTD::sort_heap(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
51333e519524SHoward Hinnant}
51343e519524SHoward Hinnant
51353e519524SHoward Hinnant// partial_sort
51363e519524SHoward Hinnant
51373e519524SHoward Hinnanttemplate <class _Compare, class _RandomAccessIterator>
51385386aa26SArthur O'Dwyer_LIBCPP_CONSTEXPR_AFTER_CXX17 void
51393e519524SHoward Hinnant__partial_sort(_RandomAccessIterator __first, _RandomAccessIterator __middle, _RandomAccessIterator __last,
51403e519524SHoward Hinnant             _Compare __comp)
51413e519524SHoward Hinnant{
51421968804aSArthur O'Dwyer    _VSTD::__make_heap<_Compare>(__first, __middle, __comp);
51433e519524SHoward Hinnant    typename iterator_traits<_RandomAccessIterator>::difference_type __len = __middle - __first;
51443e519524SHoward Hinnant    for (_RandomAccessIterator __i = __middle; __i != __last; ++__i)
51453e519524SHoward Hinnant    {
51463e519524SHoward Hinnant        if (__comp(*__i, *__first))
51473e519524SHoward Hinnant        {
51483e519524SHoward Hinnant            swap(*__i, *__first);
51491968804aSArthur O'Dwyer            _VSTD::__sift_down<_Compare>(__first, __middle, __comp, __len, __first);
51503e519524SHoward Hinnant        }
51513e519524SHoward Hinnant    }
51521968804aSArthur O'Dwyer    _VSTD::__sort_heap<_Compare>(__first, __middle, __comp);
51533e519524SHoward Hinnant}
51543e519524SHoward Hinnant
51553e519524SHoward Hinnanttemplate <class _RandomAccessIterator, class _Compare>
51565386aa26SArthur O'Dwyerinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
51573e519524SHoward Hinnantvoid
51583e519524SHoward Hinnantpartial_sort(_RandomAccessIterator __first, _RandomAccessIterator __middle, _RandomAccessIterator __last,
51593e519524SHoward Hinnant             _Compare __comp)
51603e519524SHoward Hinnant{
5161aa1cad15SEric Fiselier    typedef typename __comp_ref_type<_Compare>::type _Comp_ref;
51621968804aSArthur O'Dwyer    _VSTD::__partial_sort<_Comp_ref>(__first, __middle, __last, __comp);
51633e519524SHoward Hinnant}
51643e519524SHoward Hinnant
51653e519524SHoward Hinnanttemplate <class _RandomAccessIterator>
51665386aa26SArthur O'Dwyerinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
51673e519524SHoward Hinnantvoid
51683e519524SHoward Hinnantpartial_sort(_RandomAccessIterator __first, _RandomAccessIterator __middle, _RandomAccessIterator __last)
51693e519524SHoward Hinnant{
5170ce48a113SHoward Hinnant    _VSTD::partial_sort(__first, __middle, __last,
51713e519524SHoward Hinnant                       __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
51723e519524SHoward Hinnant}
51733e519524SHoward Hinnant
51743e519524SHoward Hinnant// partial_sort_copy
51753e519524SHoward Hinnant
51763e519524SHoward Hinnanttemplate <class _Compare, class _InputIterator, class _RandomAccessIterator>
51775386aa26SArthur O'Dwyer_LIBCPP_CONSTEXPR_AFTER_CXX17 _RandomAccessIterator
51783e519524SHoward Hinnant__partial_sort_copy(_InputIterator __first, _InputIterator __last,
51793e519524SHoward Hinnant                    _RandomAccessIterator __result_first, _RandomAccessIterator __result_last, _Compare __comp)
51803e519524SHoward Hinnant{
51813e519524SHoward Hinnant    _RandomAccessIterator __r = __result_first;
51823e519524SHoward Hinnant    if (__r != __result_last)
51833e519524SHoward Hinnant    {
51847fa68653SMarshall Clow        for (; __first != __last && __r != __result_last; ++__first, (void) ++__r)
51853e519524SHoward Hinnant            *__r = *__first;
51861968804aSArthur O'Dwyer        _VSTD::__make_heap<_Compare>(__result_first, __r, __comp);
51878b512602SDavid Majnemer        typename iterator_traits<_RandomAccessIterator>::difference_type __len = __r - __result_first;
51883e519524SHoward Hinnant        for (; __first != __last; ++__first)
51893e519524SHoward Hinnant            if (__comp(*__first, *__result_first))
51903e519524SHoward Hinnant            {
51913e519524SHoward Hinnant                *__result_first = *__first;
51921968804aSArthur O'Dwyer                _VSTD::__sift_down<_Compare>(__result_first, __r, __comp, __len, __result_first);
51933e519524SHoward Hinnant            }
51941968804aSArthur O'Dwyer        _VSTD::__sort_heap<_Compare>(__result_first, __r, __comp);
51953e519524SHoward Hinnant    }
51963e519524SHoward Hinnant    return __r;
51973e519524SHoward Hinnant}
51983e519524SHoward Hinnant
51993e519524SHoward Hinnanttemplate <class _InputIterator, class _RandomAccessIterator, class _Compare>
52005386aa26SArthur O'Dwyerinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
52013e519524SHoward Hinnant_RandomAccessIterator
52023e519524SHoward Hinnantpartial_sort_copy(_InputIterator __first, _InputIterator __last,
52033e519524SHoward Hinnant                  _RandomAccessIterator __result_first, _RandomAccessIterator __result_last, _Compare __comp)
52043e519524SHoward Hinnant{
5205aa1cad15SEric Fiselier    typedef typename __comp_ref_type<_Compare>::type _Comp_ref;
52061968804aSArthur O'Dwyer    return _VSTD::__partial_sort_copy<_Comp_ref>(__first, __last, __result_first, __result_last, __comp);
52073e519524SHoward Hinnant}
52083e519524SHoward Hinnant
52093e519524SHoward Hinnanttemplate <class _InputIterator, class _RandomAccessIterator>
52105386aa26SArthur O'Dwyerinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
52113e519524SHoward Hinnant_RandomAccessIterator
52123e519524SHoward Hinnantpartial_sort_copy(_InputIterator __first, _InputIterator __last,
52133e519524SHoward Hinnant                  _RandomAccessIterator __result_first, _RandomAccessIterator __result_last)
52143e519524SHoward Hinnant{
5215ce48a113SHoward Hinnant    return _VSTD::partial_sort_copy(__first, __last, __result_first, __result_last,
52163e519524SHoward Hinnant                                   __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
52173e519524SHoward Hinnant}
52183e519524SHoward Hinnant
52193e519524SHoward Hinnant// nth_element
52203e519524SHoward Hinnant
52213e519524SHoward Hinnanttemplate <class _Compare, class _RandomAccessIterator>
5222*b6ffece3SJordan Rupprechtvoid
52233e519524SHoward Hinnant__nth_element(_RandomAccessIterator __first, _RandomAccessIterator __nth, _RandomAccessIterator __last, _Compare __comp)
52243e519524SHoward Hinnant{
52253e519524SHoward Hinnant    // _Compare is known to be a reference type
52263e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
52273e519524SHoward Hinnant    const difference_type __limit = 7;
52283e519524SHoward Hinnant    while (true)
52293e519524SHoward Hinnant    {
5230*b6ffece3SJordan Rupprecht    __restart:
5231b34b4819SHoward Hinnant        if (__nth == __last)
5232b34b4819SHoward Hinnant            return;
52333e519524SHoward Hinnant        difference_type __len = __last - __first;
52343e519524SHoward Hinnant        switch (__len)
52353e519524SHoward Hinnant        {
52363e519524SHoward Hinnant        case 0:
52373e519524SHoward Hinnant        case 1:
52383e519524SHoward Hinnant            return;
52393e519524SHoward Hinnant        case 2:
52403e519524SHoward Hinnant            if (__comp(*--__last, *__first))
52413e519524SHoward Hinnant                swap(*__first, *__last);
52423e519524SHoward Hinnant            return;
52433e519524SHoward Hinnant        case 3:
52443e519524SHoward Hinnant            {
52453e519524SHoward Hinnant            _RandomAccessIterator __m = __first;
5246ce48a113SHoward Hinnant            _VSTD::__sort3<_Compare>(__first, ++__m, --__last, __comp);
52473e519524SHoward Hinnant            return;
52483e519524SHoward Hinnant            }
52493e519524SHoward Hinnant        }
52503e519524SHoward Hinnant        if (__len <= __limit)
52513e519524SHoward Hinnant        {
52521968804aSArthur O'Dwyer            _VSTD::__selection_sort<_Compare>(__first, __last, __comp);
52533e519524SHoward Hinnant            return;
52543e519524SHoward Hinnant        }
52553e519524SHoward Hinnant        // __len > __limit >= 3
52563e519524SHoward Hinnant        _RandomAccessIterator __m = __first + __len/2;
52573e519524SHoward Hinnant        _RandomAccessIterator __lm1 = __last;
5258ce48a113SHoward Hinnant        unsigned __n_swaps = _VSTD::__sort3<_Compare>(__first, __m, --__lm1, __comp);
52593e519524SHoward Hinnant        // *__m is median
52603e519524SHoward Hinnant        // partition [__first, __m) < *__m and *__m <= [__m, __last)
52613e519524SHoward Hinnant        // (this inhibits tossing elements equivalent to __m around unnecessarily)
52623e519524SHoward Hinnant        _RandomAccessIterator __i = __first;
52633e519524SHoward Hinnant        _RandomAccessIterator __j = __lm1;
52643e519524SHoward Hinnant        // j points beyond range to be tested, *__lm1 is known to be <= *__m
52653e519524SHoward Hinnant        // The search going up is known to be guarded but the search coming down isn't.
52663e519524SHoward Hinnant        // Prime the downward search with a guard.
52673e519524SHoward Hinnant        if (!__comp(*__i, *__m))  // if *__first == *__m
52683e519524SHoward Hinnant        {
52693e519524SHoward Hinnant            // *__first == *__m, *__first doesn't go in first part
5270*b6ffece3SJordan Rupprecht            // manually guard downward moving __j against __i
5271*b6ffece3SJordan Rupprecht            while (true)
5272*b6ffece3SJordan Rupprecht            {
5273*b6ffece3SJordan Rupprecht                if (__i == --__j)
5274*b6ffece3SJordan Rupprecht                {
5275*b6ffece3SJordan Rupprecht                    // *__first == *__m, *__m <= all other elements
5276*b6ffece3SJordan Rupprecht                    // Partition instead into [__first, __i) == *__first and *__first < [__i, __last)
5277*b6ffece3SJordan Rupprecht                    ++__i;  // __first + 1
5278*b6ffece3SJordan Rupprecht                    __j = __last;
5279*b6ffece3SJordan Rupprecht                    if (!__comp(*__first, *--__j))  // we need a guard if *__first == *(__last-1)
5280*b6ffece3SJordan Rupprecht                    {
5281*b6ffece3SJordan Rupprecht                        while (true)
5282*b6ffece3SJordan Rupprecht                        {
5283*b6ffece3SJordan Rupprecht                            if (__i == __j)
5284*b6ffece3SJordan Rupprecht                                return;  // [__first, __last) all equivalent elements
5285*b6ffece3SJordan Rupprecht                            if (__comp(*__first, *__i))
5286*b6ffece3SJordan Rupprecht                            {
52873e519524SHoward Hinnant                                swap(*__i, *__j);
52883e519524SHoward Hinnant                                ++__n_swaps;
5289*b6ffece3SJordan Rupprecht                                ++__i;
5290*b6ffece3SJordan Rupprecht                                break;
5291*b6ffece3SJordan Rupprecht                            }
5292*b6ffece3SJordan Rupprecht                            ++__i;
5293*b6ffece3SJordan Rupprecht                        }
5294*b6ffece3SJordan Rupprecht                    }
5295*b6ffece3SJordan Rupprecht                    // [__first, __i) == *__first and *__first < [__j, __last) and __j == __last - 1
5296*b6ffece3SJordan Rupprecht                    if (__i == __j)
52973e519524SHoward Hinnant                        return;
5298*b6ffece3SJordan Rupprecht                    while (true)
5299*b6ffece3SJordan Rupprecht                    {
5300*b6ffece3SJordan Rupprecht                        while (!__comp(*__first, *__i))
5301*b6ffece3SJordan Rupprecht                            ++__i;
5302*b6ffece3SJordan Rupprecht                        while (__comp(*__first, *--__j))
5303*b6ffece3SJordan Rupprecht                            ;
5304*b6ffece3SJordan Rupprecht                        if (__i >= __j)
5305*b6ffece3SJordan Rupprecht                            break;
5306*b6ffece3SJordan Rupprecht                        swap(*__i, *__j);
5307*b6ffece3SJordan Rupprecht                        ++__n_swaps;
5308*b6ffece3SJordan Rupprecht                        ++__i;
5309*b6ffece3SJordan Rupprecht                    }
5310*b6ffece3SJordan Rupprecht                    // [__first, __i) == *__first and *__first < [__i, __last)
5311*b6ffece3SJordan Rupprecht                    // The first part is sorted,
5312*b6ffece3SJordan Rupprecht                    if (__nth < __i)
53133e519524SHoward Hinnant                        return;
53141968804aSArthur O'Dwyer                    // __nth_element the second part
53151968804aSArthur O'Dwyer                    // _VSTD::__nth_element<_Compare>(__i, __nth, __last, __comp);
53163e519524SHoward Hinnant                    __first = __i;
5317*b6ffece3SJordan Rupprecht                    goto __restart;
5318*b6ffece3SJordan Rupprecht                }
5319*b6ffece3SJordan Rupprecht                if (__comp(*__j, *__m))
5320*b6ffece3SJordan Rupprecht                {
5321*b6ffece3SJordan Rupprecht                    swap(*__i, *__j);
5322*b6ffece3SJordan Rupprecht                    ++__n_swaps;
5323*b6ffece3SJordan Rupprecht                    break;  // found guard for downward moving __j, now use unguarded partition
5324*b6ffece3SJordan Rupprecht                }
53253e519524SHoward Hinnant            }
53263e519524SHoward Hinnant        }
53273e519524SHoward Hinnant        ++__i;
53283e519524SHoward Hinnant        // j points beyond range to be tested, *__lm1 is known to be <= *__m
53293e519524SHoward Hinnant        // if not yet partitioned...
53303e519524SHoward Hinnant        if (__i < __j)
53313e519524SHoward Hinnant        {
53323e519524SHoward Hinnant            // known that *(__i - 1) < *__m
53333e519524SHoward Hinnant            while (true)
53343e519524SHoward Hinnant            {
53353e519524SHoward Hinnant                // __m still guards upward moving __i
53363e519524SHoward Hinnant                while (__comp(*__i, *__m))
53373e519524SHoward Hinnant                    ++__i;
53383e519524SHoward Hinnant                // It is now known that a guard exists for downward moving __j
53393e519524SHoward Hinnant                while (!__comp(*--__j, *__m))
53403e519524SHoward Hinnant                    ;
53413e519524SHoward Hinnant                if (__i >= __j)
53423e519524SHoward Hinnant                    break;
53433e519524SHoward Hinnant                swap(*__i, *__j);
53443e519524SHoward Hinnant                ++__n_swaps;
53453e519524SHoward Hinnant                // It is known that __m != __j
53463e519524SHoward Hinnant                // If __m just moved, follow it
53473e519524SHoward Hinnant                if (__m == __i)
53483e519524SHoward Hinnant                    __m = __j;
53493e519524SHoward Hinnant                ++__i;
53503e519524SHoward Hinnant            }
53513e519524SHoward Hinnant        }
53523e519524SHoward Hinnant        // [__first, __i) < *__m and *__m <= [__i, __last)
53533e519524SHoward Hinnant        if (__i != __m && __comp(*__m, *__i))
53543e519524SHoward Hinnant        {
53553e519524SHoward Hinnant            swap(*__i, *__m);
53563e519524SHoward Hinnant            ++__n_swaps;
53573e519524SHoward Hinnant        }
53583e519524SHoward Hinnant        // [__first, __i) < *__i and *__i <= [__i+1, __last)
53593e519524SHoward Hinnant        if (__nth == __i)
53603e519524SHoward Hinnant            return;
53613e519524SHoward Hinnant        if (__n_swaps == 0)
53623e519524SHoward Hinnant        {
53633e519524SHoward Hinnant            // We were given a perfectly partitioned sequence.  Coincidence?
53643e519524SHoward Hinnant            if (__nth < __i)
53653e519524SHoward Hinnant            {
53663e519524SHoward Hinnant                // Check for [__first, __i) already sorted
53673e519524SHoward Hinnant                __j = __m = __first;
5368*b6ffece3SJordan Rupprecht                while (++__j != __i)
53693e519524SHoward Hinnant                {
5370207d4be4SArthur O'Dwyer                    if (__comp(*__j, *__m))
5371207d4be4SArthur O'Dwyer                        // not yet sorted, so sort
5372*b6ffece3SJordan Rupprecht                        goto not_sorted;
5373207d4be4SArthur O'Dwyer                    __m = __j;
5374207d4be4SArthur O'Dwyer                }
5375*b6ffece3SJordan Rupprecht                // [__first, __i) sorted
5376*b6ffece3SJordan Rupprecht                return;
53773e519524SHoward Hinnant            }
53783e519524SHoward Hinnant            else
53793e519524SHoward Hinnant            {
53803e519524SHoward Hinnant                // Check for [__i, __last) already sorted
53813e519524SHoward Hinnant                __j = __m = __i;
53823e519524SHoward Hinnant                while (++__j != __last)
53833e519524SHoward Hinnant                {
5384207d4be4SArthur O'Dwyer                    if (__comp(*__j, *__m))
5385207d4be4SArthur O'Dwyer                        // not yet sorted, so sort
5386*b6ffece3SJordan Rupprecht                        goto not_sorted;
5387207d4be4SArthur O'Dwyer                    __m = __j;
53883e519524SHoward Hinnant                }
5389*b6ffece3SJordan Rupprecht                // [__i, __last) sorted
5390*b6ffece3SJordan Rupprecht                return;
53913e519524SHoward Hinnant            }
5392207d4be4SArthur O'Dwyer        }
5393*b6ffece3SJordan Rupprechtnot_sorted:
53943e519524SHoward Hinnant        // __nth_element on range containing __nth
53953e519524SHoward Hinnant        if (__nth < __i)
53963e519524SHoward Hinnant        {
53971968804aSArthur O'Dwyer            // _VSTD::__nth_element<_Compare>(__first, __nth, __i, __comp);
53983e519524SHoward Hinnant            __last = __i;
53993e519524SHoward Hinnant        }
54003e519524SHoward Hinnant        else
54013e519524SHoward Hinnant        {
54021968804aSArthur O'Dwyer            // _VSTD::__nth_element<_Compare>(__i+1, __nth, __last, __comp);
54033e519524SHoward Hinnant            __first = ++__i;
54043e519524SHoward Hinnant        }
54053e519524SHoward Hinnant    }
54063e519524SHoward Hinnant}
54073e519524SHoward Hinnant
54083e519524SHoward Hinnanttemplate <class _RandomAccessIterator, class _Compare>
5409*b6ffece3SJordan Rupprechtinline _LIBCPP_INLINE_VISIBILITY
54103e519524SHoward Hinnantvoid
54113e519524SHoward Hinnantnth_element(_RandomAccessIterator __first, _RandomAccessIterator __nth, _RandomAccessIterator __last, _Compare __comp)
54123e519524SHoward Hinnant{
5413aa1cad15SEric Fiselier    typedef typename __comp_ref_type<_Compare>::type _Comp_ref;
54141968804aSArthur O'Dwyer    _VSTD::__nth_element<_Comp_ref>(__first, __nth, __last, __comp);
54153e519524SHoward Hinnant}
54163e519524SHoward Hinnant
54173e519524SHoward Hinnanttemplate <class _RandomAccessIterator>
5418*b6ffece3SJordan Rupprechtinline _LIBCPP_INLINE_VISIBILITY
54193e519524SHoward Hinnantvoid
54203e519524SHoward Hinnantnth_element(_RandomAccessIterator __first, _RandomAccessIterator __nth, _RandomAccessIterator __last)
54213e519524SHoward Hinnant{
5422ce48a113SHoward Hinnant    _VSTD::nth_element(__first, __nth, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
54233e519524SHoward Hinnant}
54243e519524SHoward Hinnant
5425493f1407SArthur O'Dwyer// sort
5426493f1407SArthur O'Dwyer
5427493f1407SArthur O'Dwyertemplate <class _RandomAccessIterator, class _Compare>
5428493f1407SArthur O'Dwyerinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
5429493f1407SArthur O'Dwyervoid
5430493f1407SArthur O'Dwyersort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
5431493f1407SArthur O'Dwyer{
5432493f1407SArthur O'Dwyer    typedef typename __comp_ref_type<_Compare>::type _Comp_ref;
5433493f1407SArthur O'Dwyer    if (__libcpp_is_constant_evaluated()) {
5434493f1407SArthur O'Dwyer        _VSTD::__partial_sort<_Comp_ref>(__first, __last, __last, _Comp_ref(__comp));
5435493f1407SArthur O'Dwyer    } else {
5436493f1407SArthur O'Dwyer        _VSTD::__sort<_Comp_ref>(_VSTD::__unwrap_iter(__first), _VSTD::__unwrap_iter(__last), _Comp_ref(__comp));
5437493f1407SArthur O'Dwyer    }
5438493f1407SArthur O'Dwyer}
5439493f1407SArthur O'Dwyer
5440493f1407SArthur O'Dwyertemplate <class _RandomAccessIterator>
5441493f1407SArthur O'Dwyerinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
5442493f1407SArthur O'Dwyervoid
5443493f1407SArthur O'Dwyersort(_RandomAccessIterator __first, _RandomAccessIterator __last)
5444493f1407SArthur O'Dwyer{
5445493f1407SArthur O'Dwyer    _VSTD::sort(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
5446493f1407SArthur O'Dwyer}
5447493f1407SArthur O'Dwyer
54483e519524SHoward Hinnant// includes
54493e519524SHoward Hinnant
54503e519524SHoward Hinnanttemplate <class _Compare, class _InputIterator1, class _InputIterator2>
54518da1a487SMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
54523e519524SHoward Hinnant__includes(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2,
54533e519524SHoward Hinnant           _Compare __comp)
54543e519524SHoward Hinnant{
54553e519524SHoward Hinnant    for (; __first2 != __last2; ++__first1)
54563e519524SHoward Hinnant    {
54573e519524SHoward Hinnant        if (__first1 == __last1 || __comp(*__first2, *__first1))
54583e519524SHoward Hinnant            return false;
54593e519524SHoward Hinnant        if (!__comp(*__first1, *__first2))
54603e519524SHoward Hinnant            ++__first2;
54613e519524SHoward Hinnant    }
54623e519524SHoward Hinnant    return true;
54633e519524SHoward Hinnant}
54643e519524SHoward Hinnant
54653e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _Compare>
54661362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
54671362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
54683e519524SHoward Hinnantbool
54693e519524SHoward Hinnantincludes(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2,
54703e519524SHoward Hinnant         _Compare __comp)
54713e519524SHoward Hinnant{
5472aa1cad15SEric Fiselier    typedef typename __comp_ref_type<_Compare>::type _Comp_ref;
54731968804aSArthur O'Dwyer    return _VSTD::__includes<_Comp_ref>(__first1, __last1, __first2, __last2, __comp);
54743e519524SHoward Hinnant}
54753e519524SHoward Hinnant
54763e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2>
54771362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
54781362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
54793e519524SHoward Hinnantbool
54803e519524SHoward Hinnantincludes(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2)
54813e519524SHoward Hinnant{
5482ce48a113SHoward Hinnant    return _VSTD::includes(__first1, __last1, __first2, __last2,
54833e519524SHoward Hinnant                          __less<typename iterator_traits<_InputIterator1>::value_type,
54843e519524SHoward Hinnant                                 typename iterator_traits<_InputIterator2>::value_type>());
54853e519524SHoward Hinnant}
54863e519524SHoward Hinnant
54873e519524SHoward Hinnant// set_union
54883e519524SHoward Hinnant
54893e519524SHoward Hinnanttemplate <class _Compare, class _InputIterator1, class _InputIterator2, class _OutputIterator>
549014098cf6SArthur O'Dwyer_LIBCPP_CONSTEXPR_AFTER_CXX17 _OutputIterator
54913e519524SHoward Hinnant__set_union(_InputIterator1 __first1, _InputIterator1 __last1,
54923e519524SHoward Hinnant            _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
54933e519524SHoward Hinnant{
54943e519524SHoward Hinnant    for (; __first1 != __last1; ++__result)
54953e519524SHoward Hinnant    {
54963e519524SHoward Hinnant        if (__first2 == __last2)
5497ce48a113SHoward Hinnant            return _VSTD::copy(__first1, __last1, __result);
54983e519524SHoward Hinnant        if (__comp(*__first2, *__first1))
54993e519524SHoward Hinnant        {
55003e519524SHoward Hinnant            *__result = *__first2;
55013e519524SHoward Hinnant            ++__first2;
55023e519524SHoward Hinnant        }
55033e519524SHoward Hinnant        else
55043e519524SHoward Hinnant        {
55053e519524SHoward Hinnant            if (!__comp(*__first1, *__first2))
55063e519524SHoward Hinnant                ++__first2;
550705da5b02SMarshall Clow            *__result = *__first1;
55083e519524SHoward Hinnant            ++__first1;
55093e519524SHoward Hinnant        }
55103e519524SHoward Hinnant    }
5511ce48a113SHoward Hinnant    return _VSTD::copy(__first2, __last2, __result);
55123e519524SHoward Hinnant}
55133e519524SHoward Hinnant
55143e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
551514098cf6SArthur O'Dwyerinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
55163e519524SHoward Hinnant_OutputIterator
55173e519524SHoward Hinnantset_union(_InputIterator1 __first1, _InputIterator1 __last1,
55183e519524SHoward Hinnant          _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
55193e519524SHoward Hinnant{
5520aa1cad15SEric Fiselier    typedef typename __comp_ref_type<_Compare>::type _Comp_ref;
55211968804aSArthur O'Dwyer    return _VSTD::__set_union<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __comp);
55223e519524SHoward Hinnant}
55233e519524SHoward Hinnant
55243e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _OutputIterator>
552514098cf6SArthur O'Dwyerinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
55263e519524SHoward Hinnant_OutputIterator
55273e519524SHoward Hinnantset_union(_InputIterator1 __first1, _InputIterator1 __last1,
55283e519524SHoward Hinnant          _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result)
55293e519524SHoward Hinnant{
5530ce48a113SHoward Hinnant    return _VSTD::set_union(__first1, __last1, __first2, __last2, __result,
55313e519524SHoward Hinnant                          __less<typename iterator_traits<_InputIterator1>::value_type,
55323e519524SHoward Hinnant                                 typename iterator_traits<_InputIterator2>::value_type>());
55333e519524SHoward Hinnant}
55343e519524SHoward Hinnant
55353e519524SHoward Hinnant// set_intersection
55363e519524SHoward Hinnant
55373e519524SHoward Hinnanttemplate <class _Compare, class _InputIterator1, class _InputIterator2, class _OutputIterator>
55388da1a487SMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 _OutputIterator
55393e519524SHoward Hinnant__set_intersection(_InputIterator1 __first1, _InputIterator1 __last1,
55403e519524SHoward Hinnant                   _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
55413e519524SHoward Hinnant{
55423e519524SHoward Hinnant    while (__first1 != __last1 && __first2 != __last2)
55433e519524SHoward Hinnant    {
55443e519524SHoward Hinnant        if (__comp(*__first1, *__first2))
55453e519524SHoward Hinnant            ++__first1;
55463e519524SHoward Hinnant        else
55473e519524SHoward Hinnant        {
55483e519524SHoward Hinnant            if (!__comp(*__first2, *__first1))
55493e519524SHoward Hinnant            {
55503e519524SHoward Hinnant                *__result = *__first1;
55513e519524SHoward Hinnant                ++__result;
55523e519524SHoward Hinnant                ++__first1;
55533e519524SHoward Hinnant            }
55543e519524SHoward Hinnant            ++__first2;
55553e519524SHoward Hinnant        }
55563e519524SHoward Hinnant    }
55573e519524SHoward Hinnant    return __result;
55583e519524SHoward Hinnant}
55593e519524SHoward Hinnant
55603e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
55618da1a487SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
55623e519524SHoward Hinnant_OutputIterator
55633e519524SHoward Hinnantset_intersection(_InputIterator1 __first1, _InputIterator1 __last1,
55643e519524SHoward Hinnant                 _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
55653e519524SHoward Hinnant{
5566aa1cad15SEric Fiselier    typedef typename __comp_ref_type<_Compare>::type _Comp_ref;
55671968804aSArthur O'Dwyer    return _VSTD::__set_intersection<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __comp);
55683e519524SHoward Hinnant}
55693e519524SHoward Hinnant
55703e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _OutputIterator>
55718da1a487SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
55723e519524SHoward Hinnant_OutputIterator
55733e519524SHoward Hinnantset_intersection(_InputIterator1 __first1, _InputIterator1 __last1,
55743e519524SHoward Hinnant                 _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result)
55753e519524SHoward Hinnant{
5576ce48a113SHoward Hinnant    return _VSTD::set_intersection(__first1, __last1, __first2, __last2, __result,
55773e519524SHoward Hinnant                                  __less<typename iterator_traits<_InputIterator1>::value_type,
55783e519524SHoward Hinnant                                         typename iterator_traits<_InputIterator2>::value_type>());
55793e519524SHoward Hinnant}
55803e519524SHoward Hinnant
55813e519524SHoward Hinnant// set_difference
55823e519524SHoward Hinnant
55833e519524SHoward Hinnanttemplate <class _Compare, class _InputIterator1, class _InputIterator2, class _OutputIterator>
558414098cf6SArthur O'Dwyer_LIBCPP_CONSTEXPR_AFTER_CXX17 _OutputIterator
55853e519524SHoward Hinnant__set_difference(_InputIterator1 __first1, _InputIterator1 __last1,
55863e519524SHoward Hinnant                 _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
55873e519524SHoward Hinnant{
55883e519524SHoward Hinnant    while (__first1 != __last1)
55893e519524SHoward Hinnant    {
55903e519524SHoward Hinnant        if (__first2 == __last2)
5591ce48a113SHoward Hinnant            return _VSTD::copy(__first1, __last1, __result);
55923e519524SHoward Hinnant        if (__comp(*__first1, *__first2))
55933e519524SHoward Hinnant        {
55943e519524SHoward Hinnant            *__result = *__first1;
55953e519524SHoward Hinnant            ++__result;
55963e519524SHoward Hinnant            ++__first1;
55973e519524SHoward Hinnant        }
55983e519524SHoward Hinnant        else
55993e519524SHoward Hinnant        {
56003e519524SHoward Hinnant            if (!__comp(*__first2, *__first1))
56013e519524SHoward Hinnant                ++__first1;
56023e519524SHoward Hinnant            ++__first2;
56033e519524SHoward Hinnant        }
56043e519524SHoward Hinnant    }
56053e519524SHoward Hinnant    return __result;
56063e519524SHoward Hinnant}
56073e519524SHoward Hinnant
56083e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
560914098cf6SArthur O'Dwyerinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
56103e519524SHoward Hinnant_OutputIterator
56113e519524SHoward Hinnantset_difference(_InputIterator1 __first1, _InputIterator1 __last1,
56123e519524SHoward Hinnant               _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
56133e519524SHoward Hinnant{
5614aa1cad15SEric Fiselier    typedef typename __comp_ref_type<_Compare>::type _Comp_ref;
56151968804aSArthur O'Dwyer    return _VSTD::__set_difference<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __comp);
56163e519524SHoward Hinnant}
56173e519524SHoward Hinnant
56183e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _OutputIterator>
561914098cf6SArthur O'Dwyerinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
56203e519524SHoward Hinnant_OutputIterator
56213e519524SHoward Hinnantset_difference(_InputIterator1 __first1, _InputIterator1 __last1,
56223e519524SHoward Hinnant               _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result)
56233e519524SHoward Hinnant{
5624ce48a113SHoward Hinnant    return _VSTD::set_difference(__first1, __last1, __first2, __last2, __result,
56253e519524SHoward Hinnant                                __less<typename iterator_traits<_InputIterator1>::value_type,
56263e519524SHoward Hinnant                                       typename iterator_traits<_InputIterator2>::value_type>());
56273e519524SHoward Hinnant}
56283e519524SHoward Hinnant
56293e519524SHoward Hinnant// set_symmetric_difference
56303e519524SHoward Hinnant
56313e519524SHoward Hinnanttemplate <class _Compare, class _InputIterator1, class _InputIterator2, class _OutputIterator>
563214098cf6SArthur O'Dwyer_LIBCPP_CONSTEXPR_AFTER_CXX17 _OutputIterator
56333e519524SHoward Hinnant__set_symmetric_difference(_InputIterator1 __first1, _InputIterator1 __last1,
56343e519524SHoward Hinnant                           _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
56353e519524SHoward Hinnant{
56363e519524SHoward Hinnant    while (__first1 != __last1)
56373e519524SHoward Hinnant    {
56383e519524SHoward Hinnant        if (__first2 == __last2)
5639ce48a113SHoward Hinnant            return _VSTD::copy(__first1, __last1, __result);
56403e519524SHoward Hinnant        if (__comp(*__first1, *__first2))
56413e519524SHoward Hinnant        {
56423e519524SHoward Hinnant            *__result = *__first1;
56433e519524SHoward Hinnant            ++__result;
56443e519524SHoward Hinnant            ++__first1;
56453e519524SHoward Hinnant        }
56463e519524SHoward Hinnant        else
56473e519524SHoward Hinnant        {
56483e519524SHoward Hinnant            if (__comp(*__first2, *__first1))
56493e519524SHoward Hinnant            {
56503e519524SHoward Hinnant                *__result = *__first2;
56513e519524SHoward Hinnant                ++__result;
56523e519524SHoward Hinnant            }
56533e519524SHoward Hinnant            else
56543e519524SHoward Hinnant                ++__first1;
56553e519524SHoward Hinnant            ++__first2;
56563e519524SHoward Hinnant        }
56573e519524SHoward Hinnant    }
5658ce48a113SHoward Hinnant    return _VSTD::copy(__first2, __last2, __result);
56593e519524SHoward Hinnant}
56603e519524SHoward Hinnant
56613e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
566214098cf6SArthur O'Dwyerinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
56633e519524SHoward Hinnant_OutputIterator
56643e519524SHoward Hinnantset_symmetric_difference(_InputIterator1 __first1, _InputIterator1 __last1,
56653e519524SHoward Hinnant                         _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
56663e519524SHoward Hinnant{
5667aa1cad15SEric Fiselier    typedef typename __comp_ref_type<_Compare>::type _Comp_ref;
56681968804aSArthur O'Dwyer    return _VSTD::__set_symmetric_difference<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __comp);
56693e519524SHoward Hinnant}
56703e519524SHoward Hinnant
56713e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _OutputIterator>
567214098cf6SArthur O'Dwyerinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
56733e519524SHoward Hinnant_OutputIterator
56743e519524SHoward Hinnantset_symmetric_difference(_InputIterator1 __first1, _InputIterator1 __last1,
56753e519524SHoward Hinnant                         _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result)
56763e519524SHoward Hinnant{
5677ce48a113SHoward Hinnant    return _VSTD::set_symmetric_difference(__first1, __last1, __first2, __last2, __result,
56783e519524SHoward Hinnant                                          __less<typename iterator_traits<_InputIterator1>::value_type,
56793e519524SHoward Hinnant                                                 typename iterator_traits<_InputIterator2>::value_type>());
56803e519524SHoward Hinnant}
56813e519524SHoward Hinnant
56823e519524SHoward Hinnant// lexicographical_compare
56833e519524SHoward Hinnant
56843e519524SHoward Hinnanttemplate <class _Compare, class _InputIterator1, class _InputIterator2>
56851b9a4ffdSMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
56863e519524SHoward Hinnant__lexicographical_compare(_InputIterator1 __first1, _InputIterator1 __last1,
56873e519524SHoward Hinnant                          _InputIterator2 __first2, _InputIterator2 __last2, _Compare __comp)
56883e519524SHoward Hinnant{
5689910285b2SEric Fiselier    for (; __first2 != __last2; ++__first1, (void) ++__first2)
56903e519524SHoward Hinnant    {
56913e519524SHoward Hinnant        if (__first1 == __last1 || __comp(*__first1, *__first2))
56923e519524SHoward Hinnant            return true;
56933e519524SHoward Hinnant        if (__comp(*__first2, *__first1))
56943e519524SHoward Hinnant            return false;
56953e519524SHoward Hinnant    }
56963e519524SHoward Hinnant    return false;
56973e519524SHoward Hinnant}
56983e519524SHoward Hinnant
56993e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _Compare>
57001362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
57011362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
57023e519524SHoward Hinnantbool
57033e519524SHoward Hinnantlexicographical_compare(_InputIterator1 __first1, _InputIterator1 __last1,
57043e519524SHoward Hinnant                        _InputIterator2 __first2, _InputIterator2 __last2, _Compare __comp)
57053e519524SHoward Hinnant{
5706aa1cad15SEric Fiselier    typedef typename __comp_ref_type<_Compare>::type _Comp_ref;
57071968804aSArthur O'Dwyer    return _VSTD::__lexicographical_compare<_Comp_ref>(__first1, __last1, __first2, __last2, __comp);
57083e519524SHoward Hinnant}
57093e519524SHoward Hinnant
57103e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2>
57111362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
57121362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
57133e519524SHoward Hinnantbool
57143e519524SHoward Hinnantlexicographical_compare(_InputIterator1 __first1, _InputIterator1 __last1,
57153e519524SHoward Hinnant                        _InputIterator2 __first2, _InputIterator2 __last2)
57163e519524SHoward Hinnant{
5717ce48a113SHoward Hinnant    return _VSTD::lexicographical_compare(__first1, __last1, __first2, __last2,
57183e519524SHoward Hinnant                                         __less<typename iterator_traits<_InputIterator1>::value_type,
57193e519524SHoward Hinnant                                                typename iterator_traits<_InputIterator2>::value_type>());
57203e519524SHoward Hinnant}
57213e519524SHoward Hinnant
57223e519524SHoward Hinnant// next_permutation
57233e519524SHoward Hinnant
57243e519524SHoward Hinnanttemplate <class _Compare, class _BidirectionalIterator>
5725f851db3dSArthur O'Dwyer_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
57263e519524SHoward Hinnant__next_permutation(_BidirectionalIterator __first, _BidirectionalIterator __last, _Compare __comp)
57273e519524SHoward Hinnant{
57283e519524SHoward Hinnant    _BidirectionalIterator __i = __last;
57293e519524SHoward Hinnant    if (__first == __last || __first == --__i)
57303e519524SHoward Hinnant        return false;
57313e519524SHoward Hinnant    while (true)
57323e519524SHoward Hinnant    {
57333e519524SHoward Hinnant        _BidirectionalIterator __ip1 = __i;
57343e519524SHoward Hinnant        if (__comp(*--__i, *__ip1))
57353e519524SHoward Hinnant        {
57363e519524SHoward Hinnant            _BidirectionalIterator __j = __last;
57373e519524SHoward Hinnant            while (!__comp(*__i, *--__j))
57383e519524SHoward Hinnant                ;
57393e519524SHoward Hinnant            swap(*__i, *__j);
5740ce48a113SHoward Hinnant            _VSTD::reverse(__ip1, __last);
57413e519524SHoward Hinnant            return true;
57423e519524SHoward Hinnant        }
57433e519524SHoward Hinnant        if (__i == __first)
57443e519524SHoward Hinnant        {
5745ce48a113SHoward Hinnant            _VSTD::reverse(__first, __last);
57463e519524SHoward Hinnant            return false;
57473e519524SHoward Hinnant        }
57483e519524SHoward Hinnant    }
57493e519524SHoward Hinnant}
57503e519524SHoward Hinnant
57513e519524SHoward Hinnanttemplate <class _BidirectionalIterator, class _Compare>
5752f851db3dSArthur O'Dwyerinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
57533e519524SHoward Hinnantbool
57543e519524SHoward Hinnantnext_permutation(_BidirectionalIterator __first, _BidirectionalIterator __last, _Compare __comp)
57553e519524SHoward Hinnant{
5756aa1cad15SEric Fiselier    typedef typename __comp_ref_type<_Compare>::type _Comp_ref;
57571968804aSArthur O'Dwyer    return _VSTD::__next_permutation<_Comp_ref>(__first, __last, __comp);
57583e519524SHoward Hinnant}
57593e519524SHoward Hinnant
57603e519524SHoward Hinnanttemplate <class _BidirectionalIterator>
5761f851db3dSArthur O'Dwyerinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
57623e519524SHoward Hinnantbool
57633e519524SHoward Hinnantnext_permutation(_BidirectionalIterator __first, _BidirectionalIterator __last)
57643e519524SHoward Hinnant{
5765ce48a113SHoward Hinnant    return _VSTD::next_permutation(__first, __last,
57663e519524SHoward Hinnant                                  __less<typename iterator_traits<_BidirectionalIterator>::value_type>());
57673e519524SHoward Hinnant}
57683e519524SHoward Hinnant
57693e519524SHoward Hinnant// prev_permutation
57703e519524SHoward Hinnant
57713e519524SHoward Hinnanttemplate <class _Compare, class _BidirectionalIterator>
5772f851db3dSArthur O'Dwyer_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
57733e519524SHoward Hinnant__prev_permutation(_BidirectionalIterator __first, _BidirectionalIterator __last, _Compare __comp)
57743e519524SHoward Hinnant{
57753e519524SHoward Hinnant    _BidirectionalIterator __i = __last;
57763e519524SHoward Hinnant    if (__first == __last || __first == --__i)
57773e519524SHoward Hinnant        return false;
57783e519524SHoward Hinnant    while (true)
57793e519524SHoward Hinnant    {
57803e519524SHoward Hinnant        _BidirectionalIterator __ip1 = __i;
57813e519524SHoward Hinnant        if (__comp(*__ip1, *--__i))
57823e519524SHoward Hinnant        {
57833e519524SHoward Hinnant            _BidirectionalIterator __j = __last;
57843e519524SHoward Hinnant            while (!__comp(*--__j, *__i))
57853e519524SHoward Hinnant                ;
57863e519524SHoward Hinnant            swap(*__i, *__j);
5787ce48a113SHoward Hinnant            _VSTD::reverse(__ip1, __last);
57883e519524SHoward Hinnant            return true;
57893e519524SHoward Hinnant        }
57903e519524SHoward Hinnant        if (__i == __first)
57913e519524SHoward Hinnant        {
5792ce48a113SHoward Hinnant            _VSTD::reverse(__first, __last);
57933e519524SHoward Hinnant            return false;
57943e519524SHoward Hinnant        }
57953e519524SHoward Hinnant    }
57963e519524SHoward Hinnant}
57973e519524SHoward Hinnant
57983e519524SHoward Hinnanttemplate <class _BidirectionalIterator, class _Compare>
5799f851db3dSArthur O'Dwyerinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
58003e519524SHoward Hinnantbool
58013e519524SHoward Hinnantprev_permutation(_BidirectionalIterator __first, _BidirectionalIterator __last, _Compare __comp)
58023e519524SHoward Hinnant{
5803aa1cad15SEric Fiselier    typedef typename __comp_ref_type<_Compare>::type _Comp_ref;
58041968804aSArthur O'Dwyer    return _VSTD::__prev_permutation<_Comp_ref>(__first, __last, __comp);
58053e519524SHoward Hinnant}
58063e519524SHoward Hinnant
58073e519524SHoward Hinnanttemplate <class _BidirectionalIterator>
5808f851db3dSArthur O'Dwyerinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
58093e519524SHoward Hinnantbool
58103e519524SHoward Hinnantprev_permutation(_BidirectionalIterator __first, _BidirectionalIterator __last)
58113e519524SHoward Hinnant{
5812ce48a113SHoward Hinnant    return _VSTD::prev_permutation(__first, __last,
58133e519524SHoward Hinnant                                  __less<typename iterator_traits<_BidirectionalIterator>::value_type>());
58143e519524SHoward Hinnant}
58153e519524SHoward Hinnant
58163e519524SHoward Hinnant_LIBCPP_END_NAMESPACE_STD
58173e519524SHoward Hinnant
5818a016efb1SEric Fiselier_LIBCPP_POP_MACROS
5819a016efb1SEric Fiselier
58200a06eb91SLouis Dionne#if defined(_LIBCPP_HAS_PARALLEL_ALGORITHMS) && _LIBCPP_STD_VER >= 17
582195689243SLouis Dionne#   include <__pstl_algorithm>
58220a06eb91SLouis Dionne#endif
58230a06eb91SLouis Dionne
58243e519524SHoward Hinnant#endif  // _LIBCPP_ALGORITHM
5825