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>
508694428eSMarshall Clow    InputIterator               // constexpr in C++20
513e519524SHoward Hinnant    find_if_not(InputIterator first, InputIterator last, Predicate pred);
523e519524SHoward Hinnant
533e519524SHoward Hinnanttemplate <class ForwardIterator1, class ForwardIterator2>
548694428eSMarshall Clow    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>
598694428eSMarshall Clow    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>
1883e519524SHoward Hinnant    ForwardIterator2
1893e519524SHoward Hinnant    swap_ranges(ForwardIterator1 first1, ForwardIterator1 last1, ForwardIterator2 first2);
1903e519524SHoward Hinnant
1913e519524SHoward Hinnanttemplate <class ForwardIterator1, class ForwardIterator2>
1923e519524SHoward Hinnant    void
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>
2543e519524SHoward Hinnant    ForwardIterator
2553e519524SHoward Hinnant    unique(ForwardIterator first, ForwardIterator last);
2563e519524SHoward Hinnant
2573e519524SHoward Hinnanttemplate <class ForwardIterator, class BinaryPredicate>
2583e519524SHoward Hinnant    ForwardIterator
2593e519524SHoward Hinnant    unique(ForwardIterator first, ForwardIterator last, BinaryPredicate pred);
2603e519524SHoward Hinnant
2613e519524SHoward Hinnanttemplate <class InputIterator, class OutputIterator>
2623e519524SHoward Hinnant    OutputIterator
2633e519524SHoward Hinnant    unique_copy(InputIterator first, InputIterator last, OutputIterator result);
2643e519524SHoward Hinnant
2653e519524SHoward Hinnanttemplate <class InputIterator, class OutputIterator, class BinaryPredicate>
2663e519524SHoward Hinnant    OutputIterator
2673e519524SHoward Hinnant    unique_copy(InputIterator first, InputIterator last, OutputIterator result, BinaryPredicate pred);
2683e519524SHoward Hinnant
2693e519524SHoward Hinnanttemplate <class BidirectionalIterator>
2703e519524SHoward Hinnant    void
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>
2783e519524SHoward Hinnant    ForwardIterator
2793e519524SHoward Hinnant    rotate(ForwardIterator first, ForwardIterator middle, ForwardIterator last);
2803e519524SHoward Hinnant
2813e519524SHoward Hinnanttemplate <class ForwardIterator, class OutputIterator>
2823e519524SHoward Hinnant    OutputIterator
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
3043e519524SHoward Hinnanttemplate <class InputIterator, class Predicate>
30549c7643cSMarshall Clow    constexpr bool  // constexpr in C++20
3063e519524SHoward Hinnant    is_partitioned(InputIterator first, InputIterator last, Predicate pred);
3073e519524SHoward Hinnant
3083e519524SHoward Hinnanttemplate <class ForwardIterator, class Predicate>
3093e519524SHoward Hinnant    ForwardIterator
3103e519524SHoward Hinnant    partition(ForwardIterator first, ForwardIterator last, Predicate pred);
3113e519524SHoward Hinnant
3123e519524SHoward Hinnanttemplate <class InputIterator, class OutputIterator1,
3133e519524SHoward Hinnant          class OutputIterator2, class Predicate>
3141b9a4ffdSMarshall Clow    constexpr pair<OutputIterator1, OutputIterator2>   // constexpr in C++20
3153e519524SHoward Hinnant    partition_copy(InputIterator first, InputIterator last,
3163e519524SHoward Hinnant                   OutputIterator1 out_true, OutputIterator2 out_false,
3173e519524SHoward Hinnant                   Predicate pred);
3183e519524SHoward Hinnant
3193e519524SHoward Hinnanttemplate <class ForwardIterator, class Predicate>
3203e519524SHoward Hinnant    ForwardIterator
3213e519524SHoward Hinnant    stable_partition(ForwardIterator first, ForwardIterator last, Predicate pred);
3223e519524SHoward Hinnant
3233e519524SHoward Hinnanttemplate<class ForwardIterator, class Predicate>
324d57c03ddSMarshall Clow    constexpr ForwardIterator  // constexpr in C++20
3253e519524SHoward Hinnant    partition_point(ForwardIterator first, ForwardIterator last, Predicate pred);
3263e519524SHoward Hinnant
3273e519524SHoward Hinnanttemplate <class ForwardIterator>
32849c7643cSMarshall Clow    constexpr bool  // constexpr in C++20
3293e519524SHoward Hinnant    is_sorted(ForwardIterator first, ForwardIterator last);
3303e519524SHoward Hinnant
3313e519524SHoward Hinnanttemplate <class ForwardIterator, class Compare>
3323e519524SHoward Hinnant    bool
3333e519524SHoward Hinnant    is_sorted(ForwardIterator first, ForwardIterator last, Compare comp);
3343e519524SHoward Hinnant
3353e519524SHoward Hinnanttemplate<class ForwardIterator>
336056f15e3SMarshall Clow    constexpr ForwardIterator    // constexpr in C++20
3373e519524SHoward Hinnant    is_sorted_until(ForwardIterator first, ForwardIterator last);
3383e519524SHoward Hinnant
3393e519524SHoward Hinnanttemplate <class ForwardIterator, class Compare>
340056f15e3SMarshall Clow    constexpr ForwardIterator    // constexpr in C++20
3413e519524SHoward Hinnant    is_sorted_until(ForwardIterator first, ForwardIterator last, Compare comp);
3423e519524SHoward Hinnant
3433e519524SHoward Hinnanttemplate <class RandomAccessIterator>
3443e519524SHoward Hinnant    void
3453e519524SHoward Hinnant    sort(RandomAccessIterator first, RandomAccessIterator last);
3463e519524SHoward Hinnant
3473e519524SHoward Hinnanttemplate <class RandomAccessIterator, class Compare>
3483e519524SHoward Hinnant    void
3493e519524SHoward Hinnant    sort(RandomAccessIterator first, RandomAccessIterator last, Compare comp);
3503e519524SHoward Hinnant
3513e519524SHoward Hinnanttemplate <class RandomAccessIterator>
3523e519524SHoward Hinnant    void
3533e519524SHoward Hinnant    stable_sort(RandomAccessIterator first, RandomAccessIterator last);
3543e519524SHoward Hinnant
3553e519524SHoward Hinnanttemplate <class RandomAccessIterator, class Compare>
3563e519524SHoward Hinnant    void
3573e519524SHoward Hinnant    stable_sort(RandomAccessIterator first, RandomAccessIterator last, Compare comp);
3583e519524SHoward Hinnant
3593e519524SHoward Hinnanttemplate <class RandomAccessIterator>
3603e519524SHoward Hinnant    void
3613e519524SHoward Hinnant    partial_sort(RandomAccessIterator first, RandomAccessIterator middle, RandomAccessIterator last);
3623e519524SHoward Hinnant
3633e519524SHoward Hinnanttemplate <class RandomAccessIterator, class Compare>
3643e519524SHoward Hinnant    void
3653e519524SHoward Hinnant    partial_sort(RandomAccessIterator first, RandomAccessIterator middle, RandomAccessIterator last, Compare comp);
3663e519524SHoward Hinnant
3673e519524SHoward Hinnanttemplate <class InputIterator, class RandomAccessIterator>
3683e519524SHoward Hinnant    RandomAccessIterator
3693e519524SHoward Hinnant    partial_sort_copy(InputIterator first, InputIterator last,
3703e519524SHoward Hinnant                      RandomAccessIterator result_first, RandomAccessIterator result_last);
3713e519524SHoward Hinnant
3723e519524SHoward Hinnanttemplate <class InputIterator, class RandomAccessIterator, class Compare>
3733e519524SHoward Hinnant    RandomAccessIterator
3743e519524SHoward Hinnant    partial_sort_copy(InputIterator first, InputIterator last,
3753e519524SHoward Hinnant                      RandomAccessIterator result_first, RandomAccessIterator result_last, Compare comp);
3763e519524SHoward Hinnant
3773e519524SHoward Hinnanttemplate <class RandomAccessIterator>
3783e519524SHoward Hinnant    void
3793e519524SHoward Hinnant    nth_element(RandomAccessIterator first, RandomAccessIterator nth, RandomAccessIterator last);
3803e519524SHoward Hinnant
3813e519524SHoward Hinnanttemplate <class RandomAccessIterator, class Compare>
3823e519524SHoward Hinnant    void
3833e519524SHoward Hinnant    nth_element(RandomAccessIterator first, RandomAccessIterator nth, RandomAccessIterator last, Compare comp);
3843e519524SHoward Hinnant
3853e519524SHoward Hinnanttemplate <class ForwardIterator, class T>
386d57c03ddSMarshall Clow    constexpr ForwardIterator                         // constexpr in C++20
3873e519524SHoward Hinnant    lower_bound(ForwardIterator first, ForwardIterator last, const T& value);
3883e519524SHoward Hinnant
3893e519524SHoward Hinnanttemplate <class ForwardIterator, class T, class Compare>
390d57c03ddSMarshall Clow    constexpr ForwardIterator                         // constexpr in C++20
3913e519524SHoward Hinnant    lower_bound(ForwardIterator first, ForwardIterator last, const T& value, Compare comp);
3923e519524SHoward Hinnant
3933e519524SHoward Hinnanttemplate <class ForwardIterator, class T>
394d57c03ddSMarshall Clow    constexpr ForwardIterator                         // constexpr in C++20
3953e519524SHoward Hinnant    upper_bound(ForwardIterator first, ForwardIterator last, const T& value);
3963e519524SHoward Hinnant
3973e519524SHoward Hinnanttemplate <class ForwardIterator, class T, class Compare>
398d57c03ddSMarshall Clow    constexpr ForwardIterator                         // constexpr in C++20
3993e519524SHoward Hinnant    upper_bound(ForwardIterator first, ForwardIterator last, const T& value, Compare comp);
4003e519524SHoward Hinnant
4013e519524SHoward Hinnanttemplate <class ForwardIterator, class T>
402d57c03ddSMarshall Clow    constexpr pair<ForwardIterator, ForwardIterator>  // constexpr in C++20
4033e519524SHoward Hinnant    equal_range(ForwardIterator first, ForwardIterator last, const T& value);
4043e519524SHoward Hinnant
4053e519524SHoward Hinnanttemplate <class ForwardIterator, class T, class Compare>
406d57c03ddSMarshall Clow    constexpr pair<ForwardIterator, ForwardIterator>  // constexpr in C++20
4073e519524SHoward Hinnant    equal_range(ForwardIterator first, ForwardIterator last, const T& value, Compare comp);
4083e519524SHoward Hinnant
4093e519524SHoward Hinnanttemplate <class ForwardIterator, class T>
410d57c03ddSMarshall Clow    constexpr bool                                    // constexpr in C++20
4113e519524SHoward Hinnant    binary_search(ForwardIterator first, ForwardIterator last, const T& value);
4123e519524SHoward Hinnant
4133e519524SHoward Hinnanttemplate <class ForwardIterator, class T, class Compare>
4148da1a487SMarshall Clow    constexpr bool                                    // constexpr in C++20
4153e519524SHoward Hinnant    binary_search(ForwardIterator first, ForwardIterator last, const T& value, Compare comp);
4163e519524SHoward Hinnant
4173e519524SHoward Hinnanttemplate <class InputIterator1, class InputIterator2, class OutputIterator>
4183e519524SHoward Hinnant    OutputIterator
4193e519524SHoward Hinnant    merge(InputIterator1 first1, InputIterator1 last1,
4203e519524SHoward Hinnant          InputIterator2 first2, InputIterator2 last2, OutputIterator result);
4213e519524SHoward Hinnant
4223e519524SHoward Hinnanttemplate <class InputIterator1, class InputIterator2, class OutputIterator, class Compare>
4233e519524SHoward Hinnant    OutputIterator
4243e519524SHoward Hinnant    merge(InputIterator1 first1, InputIterator1 last1,
4253e519524SHoward Hinnant          InputIterator2 first2, InputIterator2 last2, OutputIterator result, Compare comp);
4263e519524SHoward Hinnant
4273e519524SHoward Hinnanttemplate <class BidirectionalIterator>
4283e519524SHoward Hinnant    void
4293e519524SHoward Hinnant    inplace_merge(BidirectionalIterator first, BidirectionalIterator middle, BidirectionalIterator last);
4303e519524SHoward Hinnant
4313e519524SHoward Hinnanttemplate <class BidirectionalIterator, class Compare>
4323e519524SHoward Hinnant    void
4333e519524SHoward Hinnant    inplace_merge(BidirectionalIterator first, BidirectionalIterator middle, BidirectionalIterator last, Compare comp);
4343e519524SHoward Hinnant
4353e519524SHoward Hinnanttemplate <class InputIterator1, class InputIterator2>
4368da1a487SMarshall Clow    constexpr bool                                    // constexpr in C++20
4373e519524SHoward Hinnant    includes(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, InputIterator2 last2);
4383e519524SHoward Hinnant
4393e519524SHoward Hinnanttemplate <class InputIterator1, class InputIterator2, class Compare>
4408da1a487SMarshall Clow    constexpr bool                                    // constexpr in C++20
4413e519524SHoward Hinnant    includes(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, InputIterator2 last2, Compare comp);
4423e519524SHoward Hinnant
4433e519524SHoward Hinnanttemplate <class InputIterator1, class InputIterator2, class OutputIterator>
4443e519524SHoward Hinnant    OutputIterator
4453e519524SHoward Hinnant    set_union(InputIterator1 first1, InputIterator1 last1,
4463e519524SHoward Hinnant              InputIterator2 first2, InputIterator2 last2, OutputIterator result);
4473e519524SHoward Hinnant
4483e519524SHoward Hinnanttemplate <class InputIterator1, class InputIterator2, class OutputIterator, class Compare>
4493e519524SHoward Hinnant    OutputIterator
4503e519524SHoward Hinnant    set_union(InputIterator1 first1, InputIterator1 last1,
4513e519524SHoward Hinnant              InputIterator2 first2, InputIterator2 last2, OutputIterator result, Compare comp);
4523e519524SHoward Hinnant
4533e519524SHoward Hinnanttemplate <class InputIterator1, class InputIterator2, class OutputIterator>
4548da1a487SMarshall Clow    constexpr OutputIterator                         // constexpr in C++20
4553e519524SHoward Hinnant    set_intersection(InputIterator1 first1, InputIterator1 last1,
4563e519524SHoward Hinnant                     InputIterator2 first2, InputIterator2 last2, OutputIterator result);
4573e519524SHoward Hinnant
4583e519524SHoward Hinnanttemplate <class InputIterator1, class InputIterator2, class OutputIterator, class Compare>
4598da1a487SMarshall Clow    constexpr OutputIterator                         // constexpr in C++20
4603e519524SHoward Hinnant    set_intersection(InputIterator1 first1, InputIterator1 last1,
4613e519524SHoward Hinnant                     InputIterator2 first2, InputIterator2 last2, OutputIterator result, Compare comp);
4623e519524SHoward Hinnant
4633e519524SHoward Hinnanttemplate <class InputIterator1, class InputIterator2, class OutputIterator>
4643e519524SHoward Hinnant    OutputIterator
4653e519524SHoward Hinnant    set_difference(InputIterator1 first1, InputIterator1 last1,
4663e519524SHoward Hinnant                   InputIterator2 first2, InputIterator2 last2, OutputIterator result);
4673e519524SHoward Hinnant
4683e519524SHoward Hinnanttemplate <class InputIterator1, class InputIterator2, class OutputIterator, class Compare>
4693e519524SHoward Hinnant    OutputIterator
4703e519524SHoward Hinnant    set_difference(InputIterator1 first1, InputIterator1 last1,
4713e519524SHoward Hinnant                   InputIterator2 first2, InputIterator2 last2, OutputIterator result, Compare comp);
4723e519524SHoward Hinnant
4733e519524SHoward Hinnanttemplate <class InputIterator1, class InputIterator2, class OutputIterator>
4743e519524SHoward Hinnant    OutputIterator
4753e519524SHoward Hinnant    set_symmetric_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>
4793e519524SHoward Hinnant    OutputIterator
4803e519524SHoward Hinnant    set_symmetric_difference(InputIterator1 first1, InputIterator1 last1,
4813e519524SHoward Hinnant                             InputIterator2 first2, InputIterator2 last2, OutputIterator result, Compare comp);
4823e519524SHoward Hinnant
4833e519524SHoward Hinnanttemplate <class RandomAccessIterator>
4843e519524SHoward Hinnant    void
4853e519524SHoward Hinnant    push_heap(RandomAccessIterator first, RandomAccessIterator last);
4863e519524SHoward Hinnant
4873e519524SHoward Hinnanttemplate <class RandomAccessIterator, class Compare>
4883e519524SHoward Hinnant    void
4893e519524SHoward Hinnant    push_heap(RandomAccessIterator first, RandomAccessIterator last, Compare comp);
4903e519524SHoward Hinnant
4913e519524SHoward Hinnanttemplate <class RandomAccessIterator>
4923e519524SHoward Hinnant    void
4933e519524SHoward Hinnant    pop_heap(RandomAccessIterator first, RandomAccessIterator last);
4943e519524SHoward Hinnant
4953e519524SHoward Hinnanttemplate <class RandomAccessIterator, class Compare>
4963e519524SHoward Hinnant    void
4973e519524SHoward Hinnant    pop_heap(RandomAccessIterator first, RandomAccessIterator last, Compare comp);
4983e519524SHoward Hinnant
4993e519524SHoward Hinnanttemplate <class RandomAccessIterator>
5003e519524SHoward Hinnant    void
5013e519524SHoward Hinnant    make_heap(RandomAccessIterator first, RandomAccessIterator last);
5023e519524SHoward Hinnant
5033e519524SHoward Hinnanttemplate <class RandomAccessIterator, class Compare>
5043e519524SHoward Hinnant    void
5053e519524SHoward Hinnant    make_heap(RandomAccessIterator first, RandomAccessIterator last, Compare comp);
5063e519524SHoward Hinnant
5073e519524SHoward Hinnanttemplate <class RandomAccessIterator>
5083e519524SHoward Hinnant    void
5093e519524SHoward Hinnant    sort_heap(RandomAccessIterator first, RandomAccessIterator last);
5103e519524SHoward Hinnant
5113e519524SHoward Hinnanttemplate <class RandomAccessIterator, class Compare>
5123e519524SHoward Hinnant    void
5133e519524SHoward Hinnant    sort_heap(RandomAccessIterator first, RandomAccessIterator last, Compare comp);
5143e519524SHoward Hinnant
5153e519524SHoward Hinnanttemplate <class RandomAccessIterator>
51649c7643cSMarshall Clow    constexpr bool   // constexpr in C++20
5173e519524SHoward Hinnant    is_heap(RandomAccessIterator first, RandomAccessiterator last);
5183e519524SHoward Hinnant
5193e519524SHoward Hinnanttemplate <class RandomAccessIterator, class Compare>
52049c7643cSMarshall Clow    constexpr bool   // constexpr in C++20
5213e519524SHoward Hinnant    is_heap(RandomAccessIterator first, RandomAccessiterator last, Compare comp);
5223e519524SHoward Hinnant
5233e519524SHoward Hinnanttemplate <class RandomAccessIterator>
52449c7643cSMarshall Clow    constexpr RandomAccessIterator   // constexpr in C++20
5253e519524SHoward Hinnant    is_heap_until(RandomAccessIterator first, RandomAccessiterator last);
5263e519524SHoward Hinnant
5273e519524SHoward Hinnanttemplate <class RandomAccessIterator, class Compare>
52849c7643cSMarshall Clow    constexpr RandomAccessIterator   // constexpr in C++20
5293e519524SHoward Hinnant    is_heap_until(RandomAccessIterator first, RandomAccessiterator last, Compare comp);
5303e519524SHoward Hinnant
5314eb27b79SHoward Hinnanttemplate <class ForwardIterator>
5324eb27b79SHoward Hinnant    ForwardIterator
5330b0671aeSMarshall Clow    min_element(ForwardIterator first, ForwardIterator last);  // constexpr in C++14
5344eb27b79SHoward Hinnant
5354eb27b79SHoward Hinnanttemplate <class ForwardIterator, class Compare>
5364eb27b79SHoward Hinnant    ForwardIterator
5370b0671aeSMarshall Clow    min_element(ForwardIterator first, ForwardIterator last, Compare comp);  // constexpr in C++14
5384eb27b79SHoward Hinnant
5393e519524SHoward Hinnanttemplate <class T>
5403e519524SHoward Hinnant    const T&
5419d67c6d5SMarshall Clow    min(const T& a, const T& b);  // constexpr in C++14
5423e519524SHoward Hinnant
5433e519524SHoward Hinnanttemplate <class T, class Compare>
5443e519524SHoward Hinnant    const T&
5459d67c6d5SMarshall Clow    min(const T& a, const T& b, Compare comp);  // constexpr in C++14
5463e519524SHoward Hinnant
5473e519524SHoward Hinnanttemplate<class T>
5484eb27b79SHoward Hinnant    T
5499d67c6d5SMarshall Clow    min(initializer_list<T> t);  // constexpr in C++14
5503e519524SHoward Hinnant
5513e519524SHoward Hinnanttemplate<class T, class Compare>
5524eb27b79SHoward Hinnant    T
5539d67c6d5SMarshall Clow    min(initializer_list<T> t, Compare comp);  // constexpr in C++14
5543e519524SHoward Hinnant
555146c14acSMarshall Clowtemplate<class T>
556146c14acSMarshall Clow    constexpr const T& clamp( const T& v, const T& lo, const T& hi );               // C++17
557146c14acSMarshall Clow
558146c14acSMarshall Clowtemplate<class T, class Compare>
559146c14acSMarshall Clow    constexpr const T& clamp( const T& v, const T& lo, const T& hi, Compare comp ); // C++17
560146c14acSMarshall Clow
5613e519524SHoward Hinnanttemplate <class ForwardIterator>
5623e519524SHoward Hinnant    ForwardIterator
5630b0671aeSMarshall Clow    max_element(ForwardIterator first, ForwardIterator last);  // constexpr in C++14
5643e519524SHoward Hinnant
5653e519524SHoward Hinnanttemplate <class ForwardIterator, class Compare>
5663e519524SHoward Hinnant    ForwardIterator
5670b0671aeSMarshall Clow    max_element(ForwardIterator first, ForwardIterator last, Compare comp);  // constexpr in C++14
5683e519524SHoward Hinnant
5694eb27b79SHoward Hinnanttemplate <class T>
5704eb27b79SHoward Hinnant    const T&
5719d67c6d5SMarshall Clow    max(const T& a, const T& b); // constexpr in C++14
5724eb27b79SHoward Hinnant
5734eb27b79SHoward Hinnanttemplate <class T, class Compare>
5744eb27b79SHoward Hinnant    const T&
5759d67c6d5SMarshall Clow    max(const T& a, const T& b, Compare comp);  // constexpr in C++14
5764eb27b79SHoward Hinnant
5774eb27b79SHoward Hinnanttemplate<class T>
5784eb27b79SHoward Hinnant    T
5799d67c6d5SMarshall Clow    max(initializer_list<T> t);  // constexpr in C++14
5804eb27b79SHoward Hinnant
5814eb27b79SHoward Hinnanttemplate<class T, class Compare>
5824eb27b79SHoward Hinnant    T
5839d67c6d5SMarshall Clow    max(initializer_list<T> t, Compare comp);  // constexpr in C++14
5844eb27b79SHoward Hinnant
5854eb27b79SHoward Hinnanttemplate<class ForwardIterator>
5864eb27b79SHoward Hinnant    pair<ForwardIterator, ForwardIterator>
5870b0671aeSMarshall Clow    minmax_element(ForwardIterator first, ForwardIterator last);   // constexpr in C++14
5884eb27b79SHoward Hinnant
5894eb27b79SHoward Hinnanttemplate<class ForwardIterator, class Compare>
5904eb27b79SHoward Hinnant    pair<ForwardIterator, ForwardIterator>
5910b0671aeSMarshall Clow    minmax_element(ForwardIterator first, ForwardIterator last, Compare comp);   // constexpr in C++14
5924eb27b79SHoward Hinnant
5934eb27b79SHoward Hinnanttemplate<class T>
5944eb27b79SHoward Hinnant    pair<const T&, const T&>
5959d67c6d5SMarshall Clow    minmax(const T& a, const T& b);  // constexpr in C++14
5964eb27b79SHoward Hinnant
5974eb27b79SHoward Hinnanttemplate<class T, class Compare>
5984eb27b79SHoward Hinnant    pair<const T&, const T&>
5999d67c6d5SMarshall Clow    minmax(const T& a, const T& b, Compare comp);  // constexpr in C++14
6004eb27b79SHoward Hinnant
6014eb27b79SHoward Hinnanttemplate<class T>
6024eb27b79SHoward Hinnant    pair<T, T>
6039d67c6d5SMarshall Clow    minmax(initializer_list<T> t);  // constexpr in C++14
6044eb27b79SHoward Hinnant
6054eb27b79SHoward Hinnanttemplate<class T, class Compare>
6064eb27b79SHoward Hinnant    pair<T, T>
6079d67c6d5SMarshall Clow    minmax(initializer_list<T> t, Compare comp);  // constexpr in C++14
6084eb27b79SHoward Hinnant
6093e519524SHoward Hinnanttemplate <class InputIterator1, class InputIterator2>
6101b9a4ffdSMarshall Clow    constexpr bool     // constexpr in C++20
6113e519524SHoward Hinnant    lexicographical_compare(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, InputIterator2 last2);
6123e519524SHoward Hinnant
6133e519524SHoward Hinnanttemplate <class InputIterator1, class InputIterator2, class Compare>
6141b9a4ffdSMarshall Clow    constexpr bool     // constexpr in C++20
6153e519524SHoward Hinnant    lexicographical_compare(InputIterator1 first1, InputIterator1 last1,
6163e519524SHoward Hinnant                            InputIterator2 first2, InputIterator2 last2, Compare comp);
6173e519524SHoward Hinnant
6183e519524SHoward Hinnanttemplate <class BidirectionalIterator>
6193e519524SHoward Hinnant    bool
6203e519524SHoward Hinnant    next_permutation(BidirectionalIterator first, BidirectionalIterator last);
6213e519524SHoward Hinnant
6223e519524SHoward Hinnanttemplate <class BidirectionalIterator, class Compare>
6233e519524SHoward Hinnant    bool
6243e519524SHoward Hinnant    next_permutation(BidirectionalIterator first, BidirectionalIterator last, Compare comp);
6253e519524SHoward Hinnant
6263e519524SHoward Hinnanttemplate <class BidirectionalIterator>
6273e519524SHoward Hinnant    bool
6283e519524SHoward Hinnant    prev_permutation(BidirectionalIterator first, BidirectionalIterator last);
6293e519524SHoward Hinnant
6303e519524SHoward Hinnanttemplate <class BidirectionalIterator, class Compare>
6313e519524SHoward Hinnant    bool
6323e519524SHoward Hinnant    prev_permutation(BidirectionalIterator first, BidirectionalIterator last, Compare comp);
6333e519524SHoward Hinnant
6343e519524SHoward Hinnant}  // std
6353e519524SHoward Hinnant
6363e519524SHoward Hinnant*/
6373e519524SHoward Hinnant
6383e519524SHoward Hinnant#include <__config>
6393e519524SHoward Hinnant#include <initializer_list>
6403e519524SHoward Hinnant#include <type_traits>
6413e519524SHoward Hinnant#include <cstring>
642f07dd8d0SEric Fiselier#include <utility> // needed to provide swap_ranges.
6433e519524SHoward Hinnant#include <memory>
644d835e592SMarshall Clow#include <functional>
6453e519524SHoward Hinnant#include <iterator>
646a1d07d57SHoward Hinnant#include <cstddef>
647e02ee4f0SMarshall Clow#include <bit>
648f56972e2SMarshall Clow#include <version>
6495d1a701dSHoward Hinnant
650c1bd9197SEric Fiselier#include <__debug>
651c1bd9197SEric Fiselier
652073458b1SHoward Hinnant#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
6533e519524SHoward Hinnant#pragma GCC system_header
654073458b1SHoward Hinnant#endif
6553e519524SHoward Hinnant
656a016efb1SEric Fiselier_LIBCPP_PUSH_MACROS
657a016efb1SEric Fiselier#include <__undef_macros>
658a016efb1SEric Fiselier
659a016efb1SEric Fiselier
6603e519524SHoward Hinnant_LIBCPP_BEGIN_NAMESPACE_STD
6613e519524SHoward Hinnant
6629d67c6d5SMarshall Clow// I'd like to replace these with _VSTD::equal_to<void>, but can't because:
6639d67c6d5SMarshall Clow//   * That only works with C++14 and later, and
6649d67c6d5SMarshall Clow//   * We haven't included <functional> here.
6653e519524SHoward Hinnanttemplate <class _T1, class _T2 = _T1>
6663e519524SHoward Hinnantstruct __equal_to
6673e519524SHoward Hinnant{
668d8098f97SMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 bool operator()(const _T1& __x, const _T1& __y) const {return __x == __y;}
669d8098f97SMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 bool operator()(const _T1& __x, const _T2& __y) const {return __x == __y;}
670d8098f97SMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 bool operator()(const _T2& __x, const _T1& __y) const {return __x == __y;}
671d8098f97SMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 bool operator()(const _T2& __x, const _T2& __y) const {return __x == __y;}
6723e519524SHoward Hinnant};
6733e519524SHoward Hinnant
6743e519524SHoward Hinnanttemplate <class _T1>
6753e519524SHoward Hinnantstruct __equal_to<_T1, _T1>
6763e519524SHoward Hinnant{
6779d67c6d5SMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
6789d67c6d5SMarshall Clow    bool operator()(const _T1& __x, const _T1& __y) const {return __x == __y;}
6793e519524SHoward Hinnant};
6803e519524SHoward Hinnant
6813e519524SHoward Hinnanttemplate <class _T1>
6823e519524SHoward Hinnantstruct __equal_to<const _T1, _T1>
6833e519524SHoward Hinnant{
6849d67c6d5SMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
6859d67c6d5SMarshall Clow    bool operator()(const _T1& __x, const _T1& __y) const {return __x == __y;}
6863e519524SHoward Hinnant};
6873e519524SHoward Hinnant
6883e519524SHoward Hinnanttemplate <class _T1>
6893e519524SHoward Hinnantstruct __equal_to<_T1, const _T1>
6903e519524SHoward Hinnant{
6919d67c6d5SMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
6929d67c6d5SMarshall Clow    bool operator()(const _T1& __x, const _T1& __y) const {return __x == __y;}
6933e519524SHoward Hinnant};
6943e519524SHoward Hinnant
6953e519524SHoward Hinnanttemplate <class _T1, class _T2 = _T1>
6963e519524SHoward Hinnantstruct __less
6973e519524SHoward Hinnant{
6989d67c6d5SMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
6999d67c6d5SMarshall Clow    bool operator()(const _T1& __x, const _T1& __y) const {return __x < __y;}
7009d67c6d5SMarshall Clow
7019d67c6d5SMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
7029d67c6d5SMarshall Clow    bool operator()(const _T1& __x, const _T2& __y) const {return __x < __y;}
7039d67c6d5SMarshall Clow
7049d67c6d5SMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
7059d67c6d5SMarshall Clow    bool operator()(const _T2& __x, const _T1& __y) const {return __x < __y;}
7069d67c6d5SMarshall Clow
7079d67c6d5SMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
7089d67c6d5SMarshall Clow    bool operator()(const _T2& __x, const _T2& __y) const {return __x < __y;}
7093e519524SHoward Hinnant};
7103e519524SHoward Hinnant
7113e519524SHoward Hinnanttemplate <class _T1>
7123e519524SHoward Hinnantstruct __less<_T1, _T1>
7133e519524SHoward Hinnant{
7149d67c6d5SMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
7159d67c6d5SMarshall Clow    bool operator()(const _T1& __x, const _T1& __y) const {return __x < __y;}
7163e519524SHoward Hinnant};
7173e519524SHoward Hinnant
7183e519524SHoward Hinnanttemplate <class _T1>
7193e519524SHoward Hinnantstruct __less<const _T1, _T1>
7203e519524SHoward Hinnant{
7219d67c6d5SMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
7229d67c6d5SMarshall Clow    bool operator()(const _T1& __x, const _T1& __y) const {return __x < __y;}
7233e519524SHoward Hinnant};
7243e519524SHoward Hinnant
7253e519524SHoward Hinnanttemplate <class _T1>
7263e519524SHoward Hinnantstruct __less<_T1, const _T1>
7273e519524SHoward Hinnant{
7289d67c6d5SMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
7299d67c6d5SMarshall Clow    bool operator()(const _T1& __x, const _T1& __y) const {return __x < __y;}
7303e519524SHoward Hinnant};
7313e519524SHoward Hinnant
7323e519524SHoward Hinnanttemplate <class _Predicate>
733a763b36fSMarshall Clowclass __invert // invert the sense of a comparison
7343e519524SHoward Hinnant{
7353e519524SHoward Hinnantprivate:
7363e519524SHoward Hinnant    _Predicate __p_;
7373e519524SHoward Hinnantpublic:
738a763b36fSMarshall Clow    _LIBCPP_INLINE_VISIBILITY __invert() {}
7393e519524SHoward Hinnant
7403e519524SHoward Hinnant    _LIBCPP_INLINE_VISIBILITY
741a763b36fSMarshall Clow    explicit __invert(_Predicate __p) : __p_(__p) {}
7423e519524SHoward Hinnant
7433e519524SHoward Hinnant    template <class _T1>
7443e519524SHoward Hinnant    _LIBCPP_INLINE_VISIBILITY
7453e519524SHoward Hinnant    bool operator()(const _T1& __x) {return !__p_(__x);}
7463e519524SHoward Hinnant
7473e519524SHoward Hinnant    template <class _T1, class _T2>
7483e519524SHoward Hinnant    _LIBCPP_INLINE_VISIBILITY
749a763b36fSMarshall Clow    bool operator()(const _T1& __x, const _T2& __y) {return __p_(__y, __x);}
7503e519524SHoward Hinnant};
7513e519524SHoward Hinnant
75204695a75SLouis Dionne// Perform division by two quickly for positive integers (llvm.org/PR39129)
75304695a75SLouis Dionne
75404695a75SLouis Dionnetemplate <typename _Integral>
75504695a75SLouis Dionne_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
75604695a75SLouis Dionnetypename enable_if
75704695a75SLouis Dionne<
75804695a75SLouis Dionne    is_integral<_Integral>::value,
75904695a75SLouis Dionne    _Integral
76004695a75SLouis Dionne>::type
76104695a75SLouis Dionne__half_positive(_Integral __value)
76204695a75SLouis Dionne{
76304695a75SLouis Dionne    return static_cast<_Integral>(static_cast<typename make_unsigned<_Integral>::type>(__value) / 2);
76404695a75SLouis Dionne}
76504695a75SLouis Dionne
76604695a75SLouis Dionnetemplate <typename _Tp>
76704695a75SLouis Dionne_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
76804695a75SLouis Dionnetypename enable_if
76904695a75SLouis Dionne<
77004695a75SLouis Dionne    !is_integral<_Tp>::value,
77104695a75SLouis Dionne    _Tp
77204695a75SLouis Dionne>::type
77304695a75SLouis Dionne__half_positive(_Tp __value)
77404695a75SLouis Dionne{
77504695a75SLouis Dionne    return __value / 2;
77604695a75SLouis Dionne}
77704695a75SLouis Dionne
778145afa17SHoward Hinnant#ifdef _LIBCPP_DEBUG
7793e519524SHoward Hinnant
7803e519524SHoward Hinnanttemplate <class _Compare>
7813e519524SHoward Hinnantstruct __debug_less
7823e519524SHoward Hinnant{
783aa1cad15SEric Fiselier    _Compare &__comp_;
784aa1cad15SEric Fiselier    _LIBCPP_CONSTEXPR_AFTER_CXX17
7853e519524SHoward Hinnant    __debug_less(_Compare& __c) : __comp_(__c) {}
786331d2159SEric Fiselier
7873e519524SHoward Hinnant    template <class _Tp, class _Up>
7886ab51de0SThomas Anderson    _LIBCPP_CONSTEXPR_AFTER_CXX17
7893c3ccc00SThomas Anderson    bool operator()(const _Tp& __x,  const _Up& __y)
7903c3ccc00SThomas Anderson    {
7913c3ccc00SThomas Anderson        bool __r = __comp_(__x, __y);
7923c3ccc00SThomas Anderson        if (__r)
7933c3ccc00SThomas Anderson            __do_compare_assert(0, __y, __x);
7943c3ccc00SThomas Anderson        return __r;
7953c3ccc00SThomas Anderson    }
7963c3ccc00SThomas Anderson
7973c3ccc00SThomas Anderson    template <class _Tp, class _Up>
798aa1cad15SEric Fiselier    _LIBCPP_CONSTEXPR_AFTER_CXX17
7996e4ec602SEric Fiselier    bool operator()(_Tp& __x,  _Up& __y)
8003e519524SHoward Hinnant    {
8013e519524SHoward Hinnant        bool __r = __comp_(__x, __y);
8023e519524SHoward Hinnant        if (__r)
803331d2159SEric Fiselier            __do_compare_assert(0, __y, __x);
8043e519524SHoward Hinnant        return __r;
8053e519524SHoward Hinnant    }
806331d2159SEric Fiselier
807331d2159SEric Fiselier    template <class _LHS, class _RHS>
808aa1cad15SEric Fiselier    _LIBCPP_CONSTEXPR_AFTER_CXX17
809331d2159SEric Fiselier    inline _LIBCPP_INLINE_VISIBILITY
810331d2159SEric Fiselier    decltype((void)_VSTD::declval<_Compare&>()(
8116e4ec602SEric Fiselier        _VSTD::declval<_LHS &>(), _VSTD::declval<_RHS &>()))
8126e4ec602SEric Fiselier    __do_compare_assert(int, _LHS & __l, _RHS & __r) {
813331d2159SEric Fiselier        _LIBCPP_ASSERT(!__comp_(__l, __r),
814331d2159SEric Fiselier            "Comparator does not induce a strict weak ordering");
815331d2159SEric Fiselier    }
816331d2159SEric Fiselier
817331d2159SEric Fiselier    template <class _LHS, class _RHS>
818aa1cad15SEric Fiselier    _LIBCPP_CONSTEXPR_AFTER_CXX17
819331d2159SEric Fiselier    inline _LIBCPP_INLINE_VISIBILITY
8206e4ec602SEric Fiselier    void __do_compare_assert(long, _LHS &, _RHS &) {}
8213e519524SHoward Hinnant};
8223e519524SHoward Hinnant
823145afa17SHoward Hinnant#endif // _LIBCPP_DEBUG
8243e519524SHoward Hinnant
825aa1cad15SEric Fiseliertemplate <class _Comp>
826aa1cad15SEric Fiselierstruct __comp_ref_type {
827aa1cad15SEric Fiselier  // Pass the comparator by lvalue reference. Or in debug mode, using a
828aa1cad15SEric Fiselier  // debugging wrapper that stores a reference.
829aa1cad15SEric Fiselier#ifndef _LIBCPP_DEBUG
830aa1cad15SEric Fiselier  typedef typename add_lvalue_reference<_Comp>::type type;
831aa1cad15SEric Fiselier#else
832aa1cad15SEric Fiselier  typedef __debug_less<_Comp> type;
833aa1cad15SEric Fiselier#endif
834aa1cad15SEric Fiselier};
835aa1cad15SEric Fiselier
8363e519524SHoward Hinnant// all_of
8373e519524SHoward Hinnant
8383e519524SHoward Hinnanttemplate <class _InputIterator, class _Predicate>
8391362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
8401362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
8413e519524SHoward Hinnantbool
8423e519524SHoward Hinnantall_of(_InputIterator __first, _InputIterator __last, _Predicate __pred)
8433e519524SHoward Hinnant{
8443e519524SHoward Hinnant    for (; __first != __last; ++__first)
8453e519524SHoward Hinnant        if (!__pred(*__first))
8463e519524SHoward Hinnant            return false;
8473e519524SHoward Hinnant    return true;
8483e519524SHoward Hinnant}
8493e519524SHoward Hinnant
8503e519524SHoward Hinnant// any_of
8513e519524SHoward Hinnant
8523e519524SHoward Hinnanttemplate <class _InputIterator, class _Predicate>
8531362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
8541362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
8553e519524SHoward Hinnantbool
8563e519524SHoward Hinnantany_of(_InputIterator __first, _InputIterator __last, _Predicate __pred)
8573e519524SHoward Hinnant{
8583e519524SHoward Hinnant    for (; __first != __last; ++__first)
8593e519524SHoward Hinnant        if (__pred(*__first))
8603e519524SHoward Hinnant            return true;
8613e519524SHoward Hinnant    return false;
8623e519524SHoward Hinnant}
8633e519524SHoward Hinnant
8643e519524SHoward Hinnant// none_of
8653e519524SHoward Hinnant
8663e519524SHoward Hinnanttemplate <class _InputIterator, class _Predicate>
8671362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
8681362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
8693e519524SHoward Hinnantbool
8703e519524SHoward Hinnantnone_of(_InputIterator __first, _InputIterator __last, _Predicate __pred)
8713e519524SHoward Hinnant{
8723e519524SHoward Hinnant    for (; __first != __last; ++__first)
8733e519524SHoward Hinnant        if (__pred(*__first))
8743e519524SHoward Hinnant            return false;
8753e519524SHoward Hinnant    return true;
8763e519524SHoward Hinnant}
8773e519524SHoward Hinnant
8783e519524SHoward Hinnant// for_each
8793e519524SHoward Hinnant
8803e519524SHoward Hinnanttemplate <class _InputIterator, class _Function>
8811b9a4ffdSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
8823e519524SHoward Hinnant_Function
8833e519524SHoward Hinnantfor_each(_InputIterator __first, _InputIterator __last, _Function __f)
8843e519524SHoward Hinnant{
8853e519524SHoward Hinnant    for (; __first != __last; ++__first)
8863e519524SHoward Hinnant        __f(*__first);
8871c7fe126SMarshall Clow    return __f;
8883e519524SHoward Hinnant}
8893e519524SHoward Hinnant
8901d02996dSMarshall Clow#if _LIBCPP_STD_VER > 14
891d5c65ffaSMarshall Clow// for_each_n
892d5c65ffaSMarshall Clow
893d5c65ffaSMarshall Clowtemplate <class _InputIterator, class _Size, class _Function>
8941b9a4ffdSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
895d5c65ffaSMarshall Clow_InputIterator
896d5c65ffaSMarshall Clowfor_each_n(_InputIterator __first, _Size __orig_n, _Function __f)
897d5c65ffaSMarshall Clow{
898d5c65ffaSMarshall Clow    typedef decltype(__convert_to_integral(__orig_n)) _IntegralSize;
899d5c65ffaSMarshall Clow    _IntegralSize __n = __orig_n;
900d5c65ffaSMarshall Clow    while (__n > 0)
901d5c65ffaSMarshall Clow    {
902d5c65ffaSMarshall Clow         __f(*__first);
903d5c65ffaSMarshall Clow         ++__first;
904d5c65ffaSMarshall Clow         --__n;
905d5c65ffaSMarshall Clow    }
906d5c65ffaSMarshall Clow    return __first;
907d5c65ffaSMarshall Clow}
9081d02996dSMarshall Clow#endif
909d5c65ffaSMarshall Clow
9103e519524SHoward Hinnant// find
9113e519524SHoward Hinnant
9123e519524SHoward Hinnanttemplate <class _InputIterator, class _Tp>
9131362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
9141362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
9153e519524SHoward Hinnant_InputIterator
916e4383379SHoward Hinnantfind(_InputIterator __first, _InputIterator __last, const _Tp& __value_)
9173e519524SHoward Hinnant{
9183e519524SHoward Hinnant    for (; __first != __last; ++__first)
919e4383379SHoward Hinnant        if (*__first == __value_)
9203e519524SHoward Hinnant            break;
9213e519524SHoward Hinnant    return __first;
9223e519524SHoward Hinnant}
9233e519524SHoward Hinnant
9243e519524SHoward Hinnant// find_if
9253e519524SHoward Hinnant
9263e519524SHoward Hinnanttemplate <class _InputIterator, class _Predicate>
9271362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
9281362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
9293e519524SHoward Hinnant_InputIterator
9303e519524SHoward Hinnantfind_if(_InputIterator __first, _InputIterator __last, _Predicate __pred)
9313e519524SHoward Hinnant{
9323e519524SHoward Hinnant    for (; __first != __last; ++__first)
9333e519524SHoward Hinnant        if (__pred(*__first))
9343e519524SHoward Hinnant            break;
9353e519524SHoward Hinnant    return __first;
9363e519524SHoward Hinnant}
9373e519524SHoward Hinnant
9383e519524SHoward Hinnant// find_if_not
9393e519524SHoward Hinnant
9403e519524SHoward Hinnanttemplate<class _InputIterator, class _Predicate>
9411362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
9421362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
9433e519524SHoward Hinnant_InputIterator
9443e519524SHoward Hinnantfind_if_not(_InputIterator __first, _InputIterator __last, _Predicate __pred)
9453e519524SHoward Hinnant{
9463e519524SHoward Hinnant    for (; __first != __last; ++__first)
9473e519524SHoward Hinnant        if (!__pred(*__first))
9483e519524SHoward Hinnant            break;
9493e519524SHoward Hinnant    return __first;
9503e519524SHoward Hinnant}
9513e519524SHoward Hinnant
9523e519524SHoward Hinnant// find_end
9533e519524SHoward Hinnant
9543e519524SHoward Hinnanttemplate <class _BinaryPredicate, class _ForwardIterator1, class _ForwardIterator2>
9558694428eSMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator1
9563e519524SHoward Hinnant__find_end(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
9573e519524SHoward Hinnant           _ForwardIterator2 __first2, _ForwardIterator2 __last2, _BinaryPredicate __pred,
9583e519524SHoward Hinnant           forward_iterator_tag, forward_iterator_tag)
9593e519524SHoward Hinnant{
9603e519524SHoward Hinnant    // modeled after search algorithm
9613e519524SHoward Hinnant    _ForwardIterator1 __r = __last1;  // __last1 is the "default" answer
9623e519524SHoward Hinnant    if (__first2 == __last2)
9633e519524SHoward Hinnant        return __r;
9643e519524SHoward Hinnant    while (true)
9653e519524SHoward Hinnant    {
9663e519524SHoward Hinnant        while (true)
9673e519524SHoward Hinnant        {
9683e519524SHoward Hinnant            if (__first1 == __last1)         // if source exhausted return last correct answer
9693e519524SHoward Hinnant                return __r;                  //    (or __last1 if never found)
9703e519524SHoward Hinnant            if (__pred(*__first1, *__first2))
9713e519524SHoward Hinnant                break;
9723e519524SHoward Hinnant            ++__first1;
9733e519524SHoward Hinnant        }
9743e519524SHoward Hinnant        // *__first1 matches *__first2, now match elements after here
9753e519524SHoward Hinnant        _ForwardIterator1 __m1 = __first1;
9763e519524SHoward Hinnant        _ForwardIterator2 __m2 = __first2;
9773e519524SHoward Hinnant        while (true)
9783e519524SHoward Hinnant        {
9793e519524SHoward Hinnant            if (++__m2 == __last2)
9803e519524SHoward Hinnant            {                         // Pattern exhaused, record answer and search for another one
9813e519524SHoward Hinnant                __r = __first1;
9823e519524SHoward Hinnant                ++__first1;
9833e519524SHoward Hinnant                break;
9843e519524SHoward Hinnant            }
9853e519524SHoward Hinnant            if (++__m1 == __last1)     // Source exhausted, return last answer
9863e519524SHoward Hinnant                return __r;
9873e519524SHoward Hinnant            if (!__pred(*__m1, *__m2))  // mismatch, restart with a new __first
9883e519524SHoward Hinnant            {
9893e519524SHoward Hinnant                ++__first1;
9903e519524SHoward Hinnant                break;
9913e519524SHoward Hinnant            }  // else there is a match, check next elements
9923e519524SHoward Hinnant        }
9933e519524SHoward Hinnant    }
9943e519524SHoward Hinnant}
9953e519524SHoward Hinnant
9963e519524SHoward Hinnanttemplate <class _BinaryPredicate, class _BidirectionalIterator1, class _BidirectionalIterator2>
9978694428eSMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 _BidirectionalIterator1
9983e519524SHoward Hinnant__find_end(_BidirectionalIterator1 __first1, _BidirectionalIterator1 __last1,
9993e519524SHoward Hinnant           _BidirectionalIterator2 __first2, _BidirectionalIterator2 __last2, _BinaryPredicate __pred,
10003e519524SHoward Hinnant           bidirectional_iterator_tag, bidirectional_iterator_tag)
10013e519524SHoward Hinnant{
10023e519524SHoward Hinnant    // modeled after search algorithm (in reverse)
10033e519524SHoward Hinnant    if (__first2 == __last2)
10043e519524SHoward Hinnant        return __last1;  // Everything matches an empty sequence
10053e519524SHoward Hinnant    _BidirectionalIterator1 __l1 = __last1;
10063e519524SHoward Hinnant    _BidirectionalIterator2 __l2 = __last2;
10073e519524SHoward Hinnant    --__l2;
10083e519524SHoward Hinnant    while (true)
10093e519524SHoward Hinnant    {
10103e519524SHoward Hinnant        // Find last element in sequence 1 that matchs *(__last2-1), with a mininum of loop checks
10113e519524SHoward Hinnant        while (true)
10123e519524SHoward Hinnant        {
10133e519524SHoward Hinnant            if (__first1 == __l1)  // return __last1 if no element matches *__first2
10143e519524SHoward Hinnant                return __last1;
10153e519524SHoward Hinnant            if (__pred(*--__l1, *__l2))
10163e519524SHoward Hinnant                break;
10173e519524SHoward Hinnant        }
10183e519524SHoward Hinnant        // *__l1 matches *__l2, now match elements before here
10193e519524SHoward Hinnant        _BidirectionalIterator1 __m1 = __l1;
10203e519524SHoward Hinnant        _BidirectionalIterator2 __m2 = __l2;
10213e519524SHoward Hinnant        while (true)
10223e519524SHoward Hinnant        {
10233e519524SHoward Hinnant            if (__m2 == __first2)  // If pattern exhausted, __m1 is the answer (works for 1 element pattern)
10243e519524SHoward Hinnant                return __m1;
10253e519524SHoward Hinnant            if (__m1 == __first1)  // Otherwise if source exhaused, pattern not found
10263e519524SHoward Hinnant                return __last1;
10273e519524SHoward Hinnant            if (!__pred(*--__m1, *--__m2))  // if there is a mismatch, restart with a new __l1
10283e519524SHoward Hinnant            {
10293e519524SHoward Hinnant                break;
10303e519524SHoward Hinnant            }  // else there is a match, check next elements
10313e519524SHoward Hinnant        }
10323e519524SHoward Hinnant    }
10333e519524SHoward Hinnant}
10343e519524SHoward Hinnant
10353e519524SHoward Hinnanttemplate <class _BinaryPredicate, class _RandomAccessIterator1, class _RandomAccessIterator2>
10369b0af34dSMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX11 _RandomAccessIterator1
10373e519524SHoward Hinnant__find_end(_RandomAccessIterator1 __first1, _RandomAccessIterator1 __last1,
10383e519524SHoward Hinnant           _RandomAccessIterator2 __first2, _RandomAccessIterator2 __last2, _BinaryPredicate __pred,
10393e519524SHoward Hinnant           random_access_iterator_tag, random_access_iterator_tag)
10403e519524SHoward Hinnant{
10413e519524SHoward Hinnant    // Take advantage of knowing source and pattern lengths.  Stop short when source is smaller than pattern
10423e519524SHoward Hinnant    typename iterator_traits<_RandomAccessIterator2>::difference_type __len2 = __last2 - __first2;
10433e519524SHoward Hinnant    if (__len2 == 0)
10443e519524SHoward Hinnant        return __last1;
10453e519524SHoward Hinnant    typename iterator_traits<_RandomAccessIterator1>::difference_type __len1 = __last1 - __first1;
10463e519524SHoward Hinnant    if (__len1 < __len2)
10473e519524SHoward Hinnant        return __last1;
10483e519524SHoward Hinnant    const _RandomAccessIterator1 __s = __first1 + (__len2 - 1);  // End of pattern match can't go before here
10493e519524SHoward Hinnant    _RandomAccessIterator1 __l1 = __last1;
10503e519524SHoward Hinnant    _RandomAccessIterator2 __l2 = __last2;
10513e519524SHoward Hinnant    --__l2;
10523e519524SHoward Hinnant    while (true)
10533e519524SHoward Hinnant    {
10543e519524SHoward Hinnant        while (true)
10553e519524SHoward Hinnant        {
10563e519524SHoward Hinnant            if (__s == __l1)
10573e519524SHoward Hinnant                return __last1;
10583e519524SHoward Hinnant            if (__pred(*--__l1, *__l2))
10593e519524SHoward Hinnant                break;
10603e519524SHoward Hinnant        }
10613e519524SHoward Hinnant        _RandomAccessIterator1 __m1 = __l1;
10623e519524SHoward Hinnant        _RandomAccessIterator2 __m2 = __l2;
10633e519524SHoward Hinnant        while (true)
10643e519524SHoward Hinnant        {
10653e519524SHoward Hinnant            if (__m2 == __first2)
10663e519524SHoward Hinnant                return __m1;
10673e519524SHoward Hinnant                                 // no need to check range on __m1 because __s guarantees we have enough source
10683e519524SHoward Hinnant            if (!__pred(*--__m1, *--__m2))
10693e519524SHoward Hinnant            {
10703e519524SHoward Hinnant                break;
10713e519524SHoward Hinnant            }
10723e519524SHoward Hinnant        }
10733e519524SHoward Hinnant    }
10743e519524SHoward Hinnant}
10753e519524SHoward Hinnant
10763e519524SHoward Hinnanttemplate <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
10771362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
10781362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
10793e519524SHoward Hinnant_ForwardIterator1
10803e519524SHoward Hinnantfind_end(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
10813e519524SHoward Hinnant         _ForwardIterator2 __first2, _ForwardIterator2 __last2, _BinaryPredicate __pred)
10823e519524SHoward Hinnant{
1083ce48a113SHoward Hinnant    return _VSTD::__find_end<typename add_lvalue_reference<_BinaryPredicate>::type>
10843e519524SHoward Hinnant                         (__first1, __last1, __first2, __last2, __pred,
10853e519524SHoward Hinnant                          typename iterator_traits<_ForwardIterator1>::iterator_category(),
10863e519524SHoward Hinnant                          typename iterator_traits<_ForwardIterator2>::iterator_category());
10873e519524SHoward Hinnant}
10883e519524SHoward Hinnant
10893e519524SHoward Hinnanttemplate <class _ForwardIterator1, class _ForwardIterator2>
10901362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
10911362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
10923e519524SHoward Hinnant_ForwardIterator1
10933e519524SHoward Hinnantfind_end(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
10943e519524SHoward Hinnant         _ForwardIterator2 __first2, _ForwardIterator2 __last2)
10953e519524SHoward Hinnant{
10963e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator1>::value_type __v1;
10973e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator2>::value_type __v2;
1098ce48a113SHoward Hinnant    return _VSTD::find_end(__first1, __last1, __first2, __last2, __equal_to<__v1, __v2>());
10993e519524SHoward Hinnant}
11003e519524SHoward Hinnant
11013e519524SHoward Hinnant// find_first_of
11023e519524SHoward Hinnant
11033e519524SHoward Hinnanttemplate <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
11049b0af34dSMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX11 _ForwardIterator1
11059b0af34dSMarshall Clow__find_first_of_ce(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
11063e519524SHoward Hinnant              _ForwardIterator2 __first2, _ForwardIterator2 __last2, _BinaryPredicate __pred)
11073e519524SHoward Hinnant{
11083e519524SHoward Hinnant    for (; __first1 != __last1; ++__first1)
11093e519524SHoward Hinnant        for (_ForwardIterator2 __j = __first2; __j != __last2; ++__j)
11103e519524SHoward Hinnant            if (__pred(*__first1, *__j))
11113e519524SHoward Hinnant                return __first1;
11123e519524SHoward Hinnant    return __last1;
11133e519524SHoward Hinnant}
11143e519524SHoward Hinnant
11159b0af34dSMarshall Clow
11169b0af34dSMarshall Clowtemplate <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
11171362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
11181362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
11199b0af34dSMarshall Clow_ForwardIterator1
11209b0af34dSMarshall Clowfind_first_of(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
11219b0af34dSMarshall Clow              _ForwardIterator2 __first2, _ForwardIterator2 __last2, _BinaryPredicate __pred)
11229b0af34dSMarshall Clow{
11239b0af34dSMarshall Clow    return _VSTD::__find_first_of_ce(__first1, __last1, __first2, __last2, __pred);
11249b0af34dSMarshall Clow}
11259b0af34dSMarshall Clow
11263e519524SHoward Hinnanttemplate <class _ForwardIterator1, class _ForwardIterator2>
11271362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
11281362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
11293e519524SHoward Hinnant_ForwardIterator1
11303e519524SHoward Hinnantfind_first_of(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
11313e519524SHoward Hinnant              _ForwardIterator2 __first2, _ForwardIterator2 __last2)
11323e519524SHoward Hinnant{
11333e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator1>::value_type __v1;
11343e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator2>::value_type __v2;
11359b0af34dSMarshall Clow    return _VSTD::__find_first_of_ce(__first1, __last1, __first2, __last2, __equal_to<__v1, __v2>());
11363e519524SHoward Hinnant}
11373e519524SHoward Hinnant
11383e519524SHoward Hinnant// adjacent_find
11393e519524SHoward Hinnant
11403e519524SHoward Hinnanttemplate <class _ForwardIterator, class _BinaryPredicate>
11411362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
11421362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
11433e519524SHoward Hinnant_ForwardIterator
11443e519524SHoward Hinnantadjacent_find(_ForwardIterator __first, _ForwardIterator __last, _BinaryPredicate __pred)
11453e519524SHoward Hinnant{
11463e519524SHoward Hinnant    if (__first != __last)
11473e519524SHoward Hinnant    {
11483e519524SHoward Hinnant        _ForwardIterator __i = __first;
11493e519524SHoward Hinnant        while (++__i != __last)
11503e519524SHoward Hinnant        {
11513e519524SHoward Hinnant            if (__pred(*__first, *__i))
11523e519524SHoward Hinnant                return __first;
11533e519524SHoward Hinnant            __first = __i;
11543e519524SHoward Hinnant        }
11553e519524SHoward Hinnant    }
11563e519524SHoward Hinnant    return __last;
11573e519524SHoward Hinnant}
11583e519524SHoward Hinnant
11593e519524SHoward Hinnanttemplate <class _ForwardIterator>
11601362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
11611362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
11623e519524SHoward Hinnant_ForwardIterator
11633e519524SHoward Hinnantadjacent_find(_ForwardIterator __first, _ForwardIterator __last)
11643e519524SHoward Hinnant{
11653e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator>::value_type __v;
1166ce48a113SHoward Hinnant    return _VSTD::adjacent_find(__first, __last, __equal_to<__v>());
11673e519524SHoward Hinnant}
11683e519524SHoward Hinnant
11693e519524SHoward Hinnant// count
11703e519524SHoward Hinnant
11713e519524SHoward Hinnanttemplate <class _InputIterator, class _Tp>
11721362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
11731362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
11743e519524SHoward Hinnanttypename iterator_traits<_InputIterator>::difference_type
1175e4383379SHoward Hinnantcount(_InputIterator __first, _InputIterator __last, const _Tp& __value_)
11763e519524SHoward Hinnant{
11773e519524SHoward Hinnant    typename iterator_traits<_InputIterator>::difference_type __r(0);
11783e519524SHoward Hinnant    for (; __first != __last; ++__first)
1179e4383379SHoward Hinnant        if (*__first == __value_)
11803e519524SHoward Hinnant            ++__r;
11813e519524SHoward Hinnant    return __r;
11823e519524SHoward Hinnant}
11833e519524SHoward Hinnant
11843e519524SHoward Hinnant// count_if
11853e519524SHoward Hinnant
11863e519524SHoward Hinnanttemplate <class _InputIterator, class _Predicate>
11871362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
11881362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
11893e519524SHoward Hinnanttypename iterator_traits<_InputIterator>::difference_type
11903e519524SHoward Hinnantcount_if(_InputIterator __first, _InputIterator __last, _Predicate __pred)
11913e519524SHoward Hinnant{
11923e519524SHoward Hinnant    typename iterator_traits<_InputIterator>::difference_type __r(0);
11933e519524SHoward Hinnant    for (; __first != __last; ++__first)
11943e519524SHoward Hinnant        if (__pred(*__first))
11953e519524SHoward Hinnant            ++__r;
11963e519524SHoward Hinnant    return __r;
11973e519524SHoward Hinnant}
11983e519524SHoward Hinnant
11993e519524SHoward Hinnant// mismatch
12003e519524SHoward Hinnant
12013e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
12021362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
12031362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
12043e519524SHoward Hinnantpair<_InputIterator1, _InputIterator2>
12053e519524SHoward Hinnantmismatch(_InputIterator1 __first1, _InputIterator1 __last1,
12063e519524SHoward Hinnant         _InputIterator2 __first2, _BinaryPredicate __pred)
12073e519524SHoward Hinnant{
1208bd7c7b55SMarshall Clow    for (; __first1 != __last1; ++__first1, (void) ++__first2)
12093e519524SHoward Hinnant        if (!__pred(*__first1, *__first2))
12103e519524SHoward Hinnant            break;
12113e519524SHoward Hinnant    return pair<_InputIterator1, _InputIterator2>(__first1, __first2);
12123e519524SHoward Hinnant}
12133e519524SHoward Hinnant
12143e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2>
12151362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
12161362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
12173e519524SHoward Hinnantpair<_InputIterator1, _InputIterator2>
12183e519524SHoward Hinnantmismatch(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2)
12193e519524SHoward Hinnant{
12203e519524SHoward Hinnant    typedef typename iterator_traits<_InputIterator1>::value_type __v1;
12213e519524SHoward Hinnant    typedef typename iterator_traits<_InputIterator2>::value_type __v2;
1222ce48a113SHoward Hinnant    return _VSTD::mismatch(__first1, __last1, __first2, __equal_to<__v1, __v2>());
12233e519524SHoward Hinnant}
12243e519524SHoward Hinnant
12250b0bbd2fSMarshall Clow#if _LIBCPP_STD_VER > 11
12260b0bbd2fSMarshall Clowtemplate <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
12271362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
12281362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
12290b0bbd2fSMarshall Clowpair<_InputIterator1, _InputIterator2>
12300b0bbd2fSMarshall Clowmismatch(_InputIterator1 __first1, _InputIterator1 __last1,
12310b0bbd2fSMarshall Clow         _InputIterator2 __first2, _InputIterator2 __last2,
12320b0bbd2fSMarshall Clow         _BinaryPredicate __pred)
12330b0bbd2fSMarshall Clow{
1234bd7c7b55SMarshall Clow    for (; __first1 != __last1 && __first2 != __last2; ++__first1, (void) ++__first2)
12350b0bbd2fSMarshall Clow        if (!__pred(*__first1, *__first2))
12360b0bbd2fSMarshall Clow            break;
12370b0bbd2fSMarshall Clow    return pair<_InputIterator1, _InputIterator2>(__first1, __first2);
12380b0bbd2fSMarshall Clow}
12390b0bbd2fSMarshall Clow
12400b0bbd2fSMarshall Clowtemplate <class _InputIterator1, class _InputIterator2>
12411362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
12421362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
12430b0bbd2fSMarshall Clowpair<_InputIterator1, _InputIterator2>
12440b0bbd2fSMarshall Clowmismatch(_InputIterator1 __first1, _InputIterator1 __last1,
12450b0bbd2fSMarshall Clow         _InputIterator2 __first2, _InputIterator2 __last2)
12460b0bbd2fSMarshall Clow{
12470b0bbd2fSMarshall Clow    typedef typename iterator_traits<_InputIterator1>::value_type __v1;
12480b0bbd2fSMarshall Clow    typedef typename iterator_traits<_InputIterator2>::value_type __v2;
12490b0bbd2fSMarshall Clow    return _VSTD::mismatch(__first1, __last1, __first2, __last2, __equal_to<__v1, __v2>());
12500b0bbd2fSMarshall Clow}
12510b0bbd2fSMarshall Clow#endif
12520b0bbd2fSMarshall Clow
12533e519524SHoward Hinnant// equal
12543e519524SHoward Hinnant
12553e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
12561362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
12571362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
12583e519524SHoward Hinnantbool
12593e519524SHoward Hinnantequal(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _BinaryPredicate __pred)
12603e519524SHoward Hinnant{
1261910285b2SEric Fiselier    for (; __first1 != __last1; ++__first1, (void) ++__first2)
12623e519524SHoward Hinnant        if (!__pred(*__first1, *__first2))
12633e519524SHoward Hinnant            return false;
12643e519524SHoward Hinnant    return true;
12653e519524SHoward Hinnant}
12663e519524SHoward Hinnant
12673e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2>
12681362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
12691362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
12703e519524SHoward Hinnantbool
12713e519524SHoward Hinnantequal(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2)
12723e519524SHoward Hinnant{
12733e519524SHoward Hinnant    typedef typename iterator_traits<_InputIterator1>::value_type __v1;
12743e519524SHoward Hinnant    typedef typename iterator_traits<_InputIterator2>::value_type __v2;
1275ce48a113SHoward Hinnant    return _VSTD::equal(__first1, __last1, __first2, __equal_to<__v1, __v2>());
12763e519524SHoward Hinnant}
12773e519524SHoward Hinnant
12780b0bbd2fSMarshall Clow#if _LIBCPP_STD_VER > 11
12790b0bbd2fSMarshall Clowtemplate <class _BinaryPredicate, class _InputIterator1, class _InputIterator2>
12806538e28dSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
12810b0bbd2fSMarshall Clowbool
12820b0bbd2fSMarshall Clow__equal(_InputIterator1 __first1, _InputIterator1 __last1,
12830b0bbd2fSMarshall Clow        _InputIterator2 __first2, _InputIterator2 __last2, _BinaryPredicate __pred,
12840b0bbd2fSMarshall Clow        input_iterator_tag, input_iterator_tag )
12850b0bbd2fSMarshall Clow{
1286910285b2SEric Fiselier    for (; __first1 != __last1 && __first2 != __last2; ++__first1, (void) ++__first2)
12870b0bbd2fSMarshall Clow        if (!__pred(*__first1, *__first2))
12880b0bbd2fSMarshall Clow            return false;
12890b0bbd2fSMarshall Clow    return __first1 == __last1 && __first2 == __last2;
12900b0bbd2fSMarshall Clow}
12910b0bbd2fSMarshall Clow
12920b0bbd2fSMarshall Clowtemplate <class _BinaryPredicate, class _RandomAccessIterator1, class _RandomAccessIterator2>
12936538e28dSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
12940b0bbd2fSMarshall Clowbool
12950b0bbd2fSMarshall Clow__equal(_RandomAccessIterator1 __first1, _RandomAccessIterator1 __last1,
12960b0bbd2fSMarshall Clow        _RandomAccessIterator2 __first2, _RandomAccessIterator2 __last2, _BinaryPredicate __pred,
12970b0bbd2fSMarshall Clow      random_access_iterator_tag, random_access_iterator_tag )
12980b0bbd2fSMarshall Clow{
12990b0bbd2fSMarshall Clow    if ( _VSTD::distance(__first1, __last1) != _VSTD::distance(__first2, __last2))
13000b0bbd2fSMarshall Clow        return false;
13010b0bbd2fSMarshall Clow    return _VSTD::equal<_RandomAccessIterator1, _RandomAccessIterator2,
13020b0bbd2fSMarshall Clow                        typename add_lvalue_reference<_BinaryPredicate>::type>
13030b0bbd2fSMarshall Clow                       (__first1, __last1, __first2, __pred );
13040b0bbd2fSMarshall Clow}
13050b0bbd2fSMarshall Clow
13060b0bbd2fSMarshall Clowtemplate <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
13071362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
13081362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
13090b0bbd2fSMarshall Clowbool
13100b0bbd2fSMarshall Clowequal(_InputIterator1 __first1, _InputIterator1 __last1,
13110b0bbd2fSMarshall Clow      _InputIterator2 __first2, _InputIterator2 __last2, _BinaryPredicate __pred )
13120b0bbd2fSMarshall Clow{
13130b0bbd2fSMarshall Clow    return _VSTD::__equal<typename add_lvalue_reference<_BinaryPredicate>::type>
13140b0bbd2fSMarshall Clow       (__first1, __last1, __first2, __last2, __pred,
13150b0bbd2fSMarshall Clow        typename iterator_traits<_InputIterator1>::iterator_category(),
13160b0bbd2fSMarshall Clow        typename iterator_traits<_InputIterator2>::iterator_category());
13170b0bbd2fSMarshall Clow}
13180b0bbd2fSMarshall Clow
13190b0bbd2fSMarshall Clowtemplate <class _InputIterator1, class _InputIterator2>
13201362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
13211362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
13220b0bbd2fSMarshall Clowbool
13230b0bbd2fSMarshall Clowequal(_InputIterator1 __first1, _InputIterator1 __last1,
13240b0bbd2fSMarshall Clow      _InputIterator2 __first2, _InputIterator2 __last2)
13250b0bbd2fSMarshall Clow{
13260b0bbd2fSMarshall Clow    typedef typename iterator_traits<_InputIterator1>::value_type __v1;
13270b0bbd2fSMarshall Clow    typedef typename iterator_traits<_InputIterator2>::value_type __v2;
13280b0bbd2fSMarshall Clow    return _VSTD::__equal(__first1, __last1, __first2, __last2, __equal_to<__v1, __v2>(),
13290b0bbd2fSMarshall Clow        typename iterator_traits<_InputIterator1>::iterator_category(),
13300b0bbd2fSMarshall Clow        typename iterator_traits<_InputIterator2>::iterator_category());
13310b0bbd2fSMarshall Clow}
13320b0bbd2fSMarshall Clow#endif
13330b0bbd2fSMarshall Clow
13343e519524SHoward Hinnant// is_permutation
13353e519524SHoward Hinnant
13363e519524SHoward Hinnanttemplate<class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
13371362d7efSNico Weber_LIBCPP_NODISCARD_EXT _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
13383e519524SHoward Hinnantis_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
13393e519524SHoward Hinnant               _ForwardIterator2 __first2, _BinaryPredicate __pred)
13403e519524SHoward Hinnant{
134149c7643cSMarshall Clow//  shorten sequences as much as possible by lopping of any equal prefix
1342910285b2SEric Fiselier    for (; __first1 != __last1; ++__first1, (void) ++__first2)
13433e519524SHoward Hinnant        if (!__pred(*__first1, *__first2))
134449c7643cSMarshall Clow            break;
134549c7643cSMarshall Clow    if (__first1 == __last1)
13463e519524SHoward Hinnant        return true;
134749c7643cSMarshall Clow
13483e519524SHoward Hinnant//  __first1 != __last1 && *__first1 != *__first2
13493e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator1>::difference_type _D1;
1350ce48a113SHoward Hinnant    _D1 __l1 = _VSTD::distance(__first1, __last1);
13513e519524SHoward Hinnant    if (__l1 == _D1(1))
13523e519524SHoward Hinnant        return false;
1353ce48a113SHoward Hinnant    _ForwardIterator2 __last2 = _VSTD::next(__first2, __l1);
13543e519524SHoward Hinnant    // For each element in [f1, l1) see if there are the same number of
13553e519524SHoward Hinnant    //    equal elements in [f2, l2)
13563e519524SHoward Hinnant    for (_ForwardIterator1 __i = __first1; __i != __last1; ++__i)
13573e519524SHoward Hinnant    {
13583e519524SHoward Hinnant    //  Have we already counted the number of *__i in [f1, l1)?
1359939b1623SPeter Collingbourne        _ForwardIterator1 __match = __first1;
1360939b1623SPeter Collingbourne        for (; __match != __i; ++__match)
1361939b1623SPeter Collingbourne            if (__pred(*__match, *__i))
1362939b1623SPeter Collingbourne                break;
1363939b1623SPeter Collingbourne        if (__match == __i) {
13643e519524SHoward Hinnant            // Count number of *__i in [f2, l2)
13653e519524SHoward Hinnant            _D1 __c2 = 0;
13663e519524SHoward Hinnant            for (_ForwardIterator2 __j = __first2; __j != __last2; ++__j)
13673e519524SHoward Hinnant                if (__pred(*__i, *__j))
13683e519524SHoward Hinnant                    ++__c2;
13693e519524SHoward Hinnant            if (__c2 == 0)
13703e519524SHoward Hinnant                return false;
13713e519524SHoward Hinnant            // Count number of *__i in [__i, l1) (we can start with 1)
13723e519524SHoward Hinnant            _D1 __c1 = 1;
1373ce48a113SHoward Hinnant            for (_ForwardIterator1 __j = _VSTD::next(__i); __j != __last1; ++__j)
13743e519524SHoward Hinnant                if (__pred(*__i, *__j))
13753e519524SHoward Hinnant                    ++__c1;
13763e519524SHoward Hinnant            if (__c1 != __c2)
13773e519524SHoward Hinnant                return false;
13783e519524SHoward Hinnant        }
13793e519524SHoward Hinnant    }
13803e519524SHoward Hinnant    return true;
13813e519524SHoward Hinnant}
13823e519524SHoward Hinnant
13833e519524SHoward Hinnanttemplate<class _ForwardIterator1, class _ForwardIterator2>
13841362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
13851362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
13863e519524SHoward Hinnantbool
13873e519524SHoward Hinnantis_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
13883e519524SHoward Hinnant               _ForwardIterator2 __first2)
13893e519524SHoward Hinnant{
13903e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator1>::value_type __v1;
13913e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator2>::value_type __v2;
1392ce48a113SHoward Hinnant    return _VSTD::is_permutation(__first1, __last1, __first2, __equal_to<__v1, __v2>());
13933e519524SHoward Hinnant}
13943e519524SHoward Hinnant
13950b0bbd2fSMarshall Clow#if _LIBCPP_STD_VER > 11
13960b0bbd2fSMarshall Clowtemplate<class _BinaryPredicate, class _ForwardIterator1, class _ForwardIterator2>
139749c7643cSMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
13980b0bbd2fSMarshall Clow__is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
13990b0bbd2fSMarshall Clow                 _ForwardIterator2 __first2, _ForwardIterator2 __last2,
14000b0bbd2fSMarshall Clow                 _BinaryPredicate __pred,
14010b0bbd2fSMarshall Clow                 forward_iterator_tag, forward_iterator_tag )
14020b0bbd2fSMarshall Clow{
140349c7643cSMarshall Clow//  shorten sequences as much as possible by lopping of any equal prefix
1404847ee131SEric Fiselier    for (; __first1 != __last1 && __first2 != __last2; ++__first1, (void) ++__first2)
14050b0bbd2fSMarshall Clow        if (!__pred(*__first1, *__first2))
140649c7643cSMarshall Clow            break;
140749c7643cSMarshall Clow    if (__first1 == __last1)
140849c7643cSMarshall Clow        return __first2 == __last2;
140949c7643cSMarshall Clow    else if (__first2 == __last2)
141049c7643cSMarshall Clow        return false;
141149c7643cSMarshall Clow
14120b0bbd2fSMarshall Clow    typedef typename iterator_traits<_ForwardIterator1>::difference_type _D1;
14130b0bbd2fSMarshall Clow    _D1 __l1 = _VSTD::distance(__first1, __last1);
14140b0bbd2fSMarshall Clow
14150b0bbd2fSMarshall Clow    typedef typename iterator_traits<_ForwardIterator2>::difference_type _D2;
1416fce85ba4SMarshall Clow    _D2 __l2 = _VSTD::distance(__first2, __last2);
14170b0bbd2fSMarshall Clow    if (__l1 != __l2)
14180b0bbd2fSMarshall Clow        return false;
14190b0bbd2fSMarshall Clow
14200b0bbd2fSMarshall Clow    // For each element in [f1, l1) see if there are the same number of
14210b0bbd2fSMarshall Clow    //    equal elements in [f2, l2)
14220b0bbd2fSMarshall Clow    for (_ForwardIterator1 __i = __first1; __i != __last1; ++__i)
14230b0bbd2fSMarshall Clow    {
14240b0bbd2fSMarshall Clow    //  Have we already counted the number of *__i in [f1, l1)?
1425939b1623SPeter Collingbourne        _ForwardIterator1 __match = __first1;
1426939b1623SPeter Collingbourne        for (; __match != __i; ++__match)
1427939b1623SPeter Collingbourne            if (__pred(*__match, *__i))
1428939b1623SPeter Collingbourne                break;
1429939b1623SPeter Collingbourne        if (__match == __i) {
14300b0bbd2fSMarshall Clow            // Count number of *__i in [f2, l2)
14310b0bbd2fSMarshall Clow            _D1 __c2 = 0;
14320b0bbd2fSMarshall Clow            for (_ForwardIterator2 __j = __first2; __j != __last2; ++__j)
14330b0bbd2fSMarshall Clow                if (__pred(*__i, *__j))
14340b0bbd2fSMarshall Clow                    ++__c2;
14350b0bbd2fSMarshall Clow            if (__c2 == 0)
14360b0bbd2fSMarshall Clow                return false;
14370b0bbd2fSMarshall Clow            // Count number of *__i in [__i, l1) (we can start with 1)
14380b0bbd2fSMarshall Clow            _D1 __c1 = 1;
14390b0bbd2fSMarshall Clow            for (_ForwardIterator1 __j = _VSTD::next(__i); __j != __last1; ++__j)
14400b0bbd2fSMarshall Clow                if (__pred(*__i, *__j))
14410b0bbd2fSMarshall Clow                    ++__c1;
14420b0bbd2fSMarshall Clow            if (__c1 != __c2)
14430b0bbd2fSMarshall Clow                return false;
14440b0bbd2fSMarshall Clow        }
14450b0bbd2fSMarshall Clow    }
14460b0bbd2fSMarshall Clow    return true;
14470b0bbd2fSMarshall Clow}
14480b0bbd2fSMarshall Clow
14490b0bbd2fSMarshall Clowtemplate<class _BinaryPredicate, class _RandomAccessIterator1, class _RandomAccessIterator2>
145049c7643cSMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
14510b0bbd2fSMarshall Clow__is_permutation(_RandomAccessIterator1 __first1, _RandomAccessIterator2 __last1,
14520b0bbd2fSMarshall Clow               _RandomAccessIterator1 __first2, _RandomAccessIterator2 __last2,
14530b0bbd2fSMarshall Clow               _BinaryPredicate __pred,
14540b0bbd2fSMarshall Clow               random_access_iterator_tag, random_access_iterator_tag )
14550b0bbd2fSMarshall Clow{
14560b0bbd2fSMarshall Clow    if ( _VSTD::distance(__first1, __last1) != _VSTD::distance(__first2, __last2))
14570b0bbd2fSMarshall Clow        return false;
14580b0bbd2fSMarshall Clow    return _VSTD::is_permutation<_RandomAccessIterator1, _RandomAccessIterator2,
14590b0bbd2fSMarshall Clow                                 typename add_lvalue_reference<_BinaryPredicate>::type>
14600b0bbd2fSMarshall Clow                                (__first1, __last1, __first2, __pred );
14610b0bbd2fSMarshall Clow}
14620b0bbd2fSMarshall Clow
14630b0bbd2fSMarshall Clowtemplate<class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
14641362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
14651362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
14660b0bbd2fSMarshall Clowbool
14670b0bbd2fSMarshall Clowis_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
14680b0bbd2fSMarshall Clow               _ForwardIterator2 __first2, _ForwardIterator2 __last2,
14690b0bbd2fSMarshall Clow               _BinaryPredicate __pred )
14700b0bbd2fSMarshall Clow{
14710b0bbd2fSMarshall Clow    return _VSTD::__is_permutation<typename add_lvalue_reference<_BinaryPredicate>::type>
14720b0bbd2fSMarshall Clow       (__first1, __last1, __first2, __last2, __pred,
14730b0bbd2fSMarshall Clow        typename iterator_traits<_ForwardIterator1>::iterator_category(),
14740b0bbd2fSMarshall Clow        typename iterator_traits<_ForwardIterator2>::iterator_category());
14750b0bbd2fSMarshall Clow}
14760b0bbd2fSMarshall Clow
14770b0bbd2fSMarshall Clowtemplate<class _ForwardIterator1, class _ForwardIterator2>
14781362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
14791362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
14800b0bbd2fSMarshall Clowbool
14810b0bbd2fSMarshall Clowis_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
14820b0bbd2fSMarshall Clow               _ForwardIterator2 __first2, _ForwardIterator2 __last2)
14830b0bbd2fSMarshall Clow{
14840b0bbd2fSMarshall Clow    typedef typename iterator_traits<_ForwardIterator1>::value_type __v1;
14850b0bbd2fSMarshall Clow    typedef typename iterator_traits<_ForwardIterator2>::value_type __v2;
14860b0bbd2fSMarshall Clow    return _VSTD::__is_permutation(__first1, __last1, __first2, __last2,
14870b0bbd2fSMarshall Clow        __equal_to<__v1, __v2>(),
14880b0bbd2fSMarshall Clow        typename iterator_traits<_ForwardIterator1>::iterator_category(),
14890b0bbd2fSMarshall Clow        typename iterator_traits<_ForwardIterator2>::iterator_category());
14900b0bbd2fSMarshall Clow}
14910b0bbd2fSMarshall Clow#endif
14920b0bbd2fSMarshall Clow
14933e519524SHoward Hinnant// search
1494d835e592SMarshall Clow// __search is in <functional>
14953e519524SHoward Hinnant
14963e519524SHoward Hinnanttemplate <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
14971362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
14981362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
14993e519524SHoward Hinnant_ForwardIterator1
15003e519524SHoward Hinnantsearch(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
15013e519524SHoward Hinnant       _ForwardIterator2 __first2, _ForwardIterator2 __last2, _BinaryPredicate __pred)
15023e519524SHoward Hinnant{
1503ce48a113SHoward Hinnant    return _VSTD::__search<typename add_lvalue_reference<_BinaryPredicate>::type>
15043e519524SHoward Hinnant                         (__first1, __last1, __first2, __last2, __pred,
150528cc4ddeSMarshall Clow                          typename iterator_traits<_ForwardIterator1>::iterator_category(),
150628cc4ddeSMarshall Clow                          typename iterator_traits<_ForwardIterator2>::iterator_category())
150728cc4ddeSMarshall Clow            .first;
15083e519524SHoward Hinnant}
15093e519524SHoward Hinnant
15103e519524SHoward Hinnanttemplate <class _ForwardIterator1, class _ForwardIterator2>
15111362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
15121362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
15133e519524SHoward Hinnant_ForwardIterator1
15143e519524SHoward Hinnantsearch(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
15153e519524SHoward Hinnant       _ForwardIterator2 __first2, _ForwardIterator2 __last2)
15163e519524SHoward Hinnant{
151728cc4ddeSMarshall Clow    typedef typename iterator_traits<_ForwardIterator1>::value_type __v1;
151828cc4ddeSMarshall Clow    typedef typename iterator_traits<_ForwardIterator2>::value_type __v2;
1519ce48a113SHoward Hinnant    return _VSTD::search(__first1, __last1, __first2, __last2, __equal_to<__v1, __v2>());
15203e519524SHoward Hinnant}
15213e519524SHoward Hinnant
1522d835e592SMarshall Clow
1523d835e592SMarshall Clow#if _LIBCPP_STD_VER > 14
1524d835e592SMarshall Clowtemplate <class _ForwardIterator, class _Searcher>
15251362d7efSNico Weber_LIBCPP_NODISCARD_EXT _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
1526d835e592SMarshall Clow_ForwardIterator search(_ForwardIterator __f, _ForwardIterator __l, const _Searcher &__s)
1527d835e592SMarshall Clow{ return __s(__f, __l).first; }
1528d835e592SMarshall Clow#endif
1529d835e592SMarshall Clow
15303e519524SHoward Hinnant// search_n
15313e519524SHoward Hinnant
15323e519524SHoward Hinnanttemplate <class _BinaryPredicate, class _ForwardIterator, class _Size, class _Tp>
153312f0a779SMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
15343e519524SHoward Hinnant__search_n(_ForwardIterator __first, _ForwardIterator __last,
1535e4383379SHoward Hinnant           _Size __count, const _Tp& __value_, _BinaryPredicate __pred, forward_iterator_tag)
15363e519524SHoward Hinnant{
15373e519524SHoward Hinnant    if (__count <= 0)
15383e519524SHoward Hinnant        return __first;
15393e519524SHoward Hinnant    while (true)
15403e519524SHoward Hinnant    {
1541e4383379SHoward Hinnant        // Find first element in sequence that matchs __value_, with a mininum of loop checks
15423e519524SHoward Hinnant        while (true)
15433e519524SHoward Hinnant        {
1544e4383379SHoward Hinnant            if (__first == __last)  // return __last if no element matches __value_
15453e519524SHoward Hinnant                return __last;
1546e4383379SHoward Hinnant            if (__pred(*__first, __value_))
15473e519524SHoward Hinnant                break;
15483e519524SHoward Hinnant            ++__first;
15493e519524SHoward Hinnant        }
1550e4383379SHoward Hinnant        // *__first matches __value_, now match elements after here
15513e519524SHoward Hinnant        _ForwardIterator __m = __first;
15523e519524SHoward Hinnant        _Size __c(0);
15533e519524SHoward Hinnant        while (true)
15543e519524SHoward Hinnant        {
15553e519524SHoward Hinnant            if (++__c == __count)  // If pattern exhausted, __first is the answer (works for 1 element pattern)
15563e519524SHoward Hinnant                return __first;
15573e519524SHoward Hinnant            if (++__m == __last)  // Otherwise if source exhaused, pattern not found
15583e519524SHoward Hinnant                return __last;
1559e4383379SHoward Hinnant            if (!__pred(*__m, __value_))  // if there is a mismatch, restart with a new __first
15603e519524SHoward Hinnant            {
15613e519524SHoward Hinnant                __first = __m;
15623e519524SHoward Hinnant                ++__first;
15633e519524SHoward Hinnant                break;
15643e519524SHoward Hinnant            }  // else there is a match, check next elements
15653e519524SHoward Hinnant        }
15663e519524SHoward Hinnant    }
15673e519524SHoward Hinnant}
15683e519524SHoward Hinnant
15693e519524SHoward Hinnanttemplate <class _BinaryPredicate, class _RandomAccessIterator, class _Size, class _Tp>
157012f0a779SMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 _RandomAccessIterator
15713e519524SHoward Hinnant__search_n(_RandomAccessIterator __first, _RandomAccessIterator __last,
1572e4383379SHoward Hinnant           _Size __count, const _Tp& __value_, _BinaryPredicate __pred, random_access_iterator_tag)
15733e519524SHoward Hinnant{
15743e519524SHoward Hinnant    if (__count <= 0)
15753e519524SHoward Hinnant        return __first;
15763e519524SHoward Hinnant    _Size __len = static_cast<_Size>(__last - __first);
15773e519524SHoward Hinnant    if (__len < __count)
15783e519524SHoward Hinnant        return __last;
15793e519524SHoward Hinnant    const _RandomAccessIterator __s = __last - (__count - 1);  // Start of pattern match can't go beyond here
15803e519524SHoward Hinnant    while (true)
15813e519524SHoward Hinnant    {
1582e4383379SHoward Hinnant        // Find first element in sequence that matchs __value_, with a mininum of loop checks
15833e519524SHoward Hinnant        while (true)
15843e519524SHoward Hinnant        {
1585b13fcad6SHoward Hinnant            if (__first >= __s)  // return __last if no element matches __value_
15863e519524SHoward Hinnant                return __last;
1587e4383379SHoward Hinnant            if (__pred(*__first, __value_))
15883e519524SHoward Hinnant                break;
15893e519524SHoward Hinnant            ++__first;
15903e519524SHoward Hinnant        }
1591e4383379SHoward Hinnant        // *__first matches __value_, now match elements after here
15923e519524SHoward Hinnant        _RandomAccessIterator __m = __first;
15933e519524SHoward Hinnant        _Size __c(0);
15943e519524SHoward Hinnant        while (true)
15953e519524SHoward Hinnant        {
15963e519524SHoward Hinnant            if (++__c == __count)  // If pattern exhausted, __first is the answer (works for 1 element pattern)
15973e519524SHoward Hinnant                return __first;
15983e519524SHoward Hinnant             ++__m;          // no need to check range on __m because __s guarantees we have enough source
1599e4383379SHoward Hinnant            if (!__pred(*__m, __value_))  // if there is a mismatch, restart with a new __first
16003e519524SHoward Hinnant            {
16013e519524SHoward Hinnant                __first = __m;
16023e519524SHoward Hinnant                ++__first;
16033e519524SHoward Hinnant                break;
16043e519524SHoward Hinnant            }  // else there is a match, check next elements
16053e519524SHoward Hinnant        }
16063e519524SHoward Hinnant    }
16073e519524SHoward Hinnant}
16083e519524SHoward Hinnant
16093e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Size, class _Tp, class _BinaryPredicate>
16101362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
16111362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
16123e519524SHoward Hinnant_ForwardIterator
16133e519524SHoward Hinnantsearch_n(_ForwardIterator __first, _ForwardIterator __last,
1614e4383379SHoward Hinnant         _Size __count, const _Tp& __value_, _BinaryPredicate __pred)
16153e519524SHoward Hinnant{
1616ce48a113SHoward Hinnant    return _VSTD::__search_n<typename add_lvalue_reference<_BinaryPredicate>::type>
161751544023SEric Fiselier           (__first, __last, __convert_to_integral(__count), __value_, __pred,
161851544023SEric Fiselier           typename iterator_traits<_ForwardIterator>::iterator_category());
16193e519524SHoward Hinnant}
16203e519524SHoward Hinnant
16213e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Size, class _Tp>
16221362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
16231362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
16243e519524SHoward Hinnant_ForwardIterator
1625e4383379SHoward Hinnantsearch_n(_ForwardIterator __first, _ForwardIterator __last, _Size __count, const _Tp& __value_)
16263e519524SHoward Hinnant{
16273e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator>::value_type __v;
162851544023SEric Fiselier    return _VSTD::search_n(__first, __last, __convert_to_integral(__count),
162951544023SEric Fiselier                           __value_, __equal_to<__v, _Tp>());
16303e519524SHoward Hinnant}
16313e519524SHoward Hinnant
16323e519524SHoward Hinnant// copy
16333e519524SHoward Hinnanttemplate <class _Iter>
1634*1ec02efeSzoecarverinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
16353e519524SHoward Hinnant_Iter
16363e519524SHoward Hinnant__unwrap_iter(_Iter __i)
16373e519524SHoward Hinnant{
16383e519524SHoward Hinnant    return __i;
16393e519524SHoward Hinnant}
16403e519524SHoward Hinnant
16413e519524SHoward Hinnanttemplate <class _Tp>
1642*1ec02efeSzoecarverinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
16433e519524SHoward Hinnanttypename enable_if
16443e519524SHoward Hinnant<
1645ca740483SHoward Hinnant    is_trivially_copy_assignable<_Tp>::value,
16463e519524SHoward Hinnant    _Tp*
16473e519524SHoward Hinnant>::type
16483e519524SHoward Hinnant__unwrap_iter(move_iterator<_Tp*> __i)
16493e519524SHoward Hinnant{
16503e519524SHoward Hinnant    return __i.base();
16513e519524SHoward Hinnant}
16523e519524SHoward Hinnant
1653fc88dbd2SHoward Hinnant#if _LIBCPP_DEBUG_LEVEL < 2
1654fc88dbd2SHoward Hinnant
16553e519524SHoward Hinnanttemplate <class _Tp>
1656*1ec02efeSzoecarverinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
16573e519524SHoward Hinnanttypename enable_if
16583e519524SHoward Hinnant<
1659ca740483SHoward Hinnant    is_trivially_copy_assignable<_Tp>::value,
16603e519524SHoward Hinnant    _Tp*
16613e519524SHoward Hinnant>::type
16623e519524SHoward Hinnant__unwrap_iter(__wrap_iter<_Tp*> __i)
16633e519524SHoward Hinnant{
16643e519524SHoward Hinnant    return __i.base();
16653e519524SHoward Hinnant}
16663e519524SHoward Hinnant
1667c8879ab2SMarshall Clowtemplate <class _Tp>
1668*1ec02efeSzoecarverinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
1669c8879ab2SMarshall Clowtypename enable_if
1670c8879ab2SMarshall Clow<
1671c8879ab2SMarshall Clow    is_trivially_copy_assignable<_Tp>::value,
1672c8879ab2SMarshall Clow    const _Tp*
1673c8879ab2SMarshall Clow>::type
1674c8879ab2SMarshall Clow__unwrap_iter(__wrap_iter<const _Tp*> __i)
1675c8879ab2SMarshall Clow{
1676c8879ab2SMarshall Clow    return __i.base();
1677c8879ab2SMarshall Clow}
1678c8879ab2SMarshall Clow
167914bd0bf0SEric Fiselier#else
168014bd0bf0SEric Fiselier
168114bd0bf0SEric Fiseliertemplate <class _Tp>
1682*1ec02efeSzoecarverinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
168314bd0bf0SEric Fiseliertypename enable_if
168414bd0bf0SEric Fiselier<
168514bd0bf0SEric Fiselier    is_trivially_copy_assignable<_Tp>::value,
168614bd0bf0SEric Fiselier    __wrap_iter<_Tp*>
168714bd0bf0SEric Fiselier>::type
168814bd0bf0SEric Fiselier__unwrap_iter(__wrap_iter<_Tp*> __i)
168914bd0bf0SEric Fiselier{
169014bd0bf0SEric Fiselier    return __i;
169114bd0bf0SEric Fiselier}
169214bd0bf0SEric Fiselier
1693fc88dbd2SHoward Hinnant#endif  // _LIBCPP_DEBUG_LEVEL < 2
1694fc88dbd2SHoward Hinnant
16953e519524SHoward Hinnanttemplate <class _InputIterator, class _OutputIterator>
169613c90a57SLouis Dionneinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
16973e519524SHoward Hinnant_OutputIterator
169813c90a57SLouis Dionne__copy_constexpr(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
16993e519524SHoward Hinnant{
1700910285b2SEric Fiselier    for (; __first != __last; ++__first, (void) ++__result)
17013e519524SHoward Hinnant        *__result = *__first;
17023e519524SHoward Hinnant    return __result;
17033e519524SHoward Hinnant}
17043e519524SHoward Hinnant
170513c90a57SLouis Dionnetemplate <class _InputIterator, class _OutputIterator>
170613c90a57SLouis Dionneinline _LIBCPP_INLINE_VISIBILITY
170713c90a57SLouis Dionne_OutputIterator
170813c90a57SLouis Dionne__copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
170913c90a57SLouis Dionne{
171013c90a57SLouis Dionne    return __copy_constexpr(__first, __last, __result);
171113c90a57SLouis Dionne}
171213c90a57SLouis Dionne
17133e519524SHoward Hinnanttemplate <class _Tp, class _Up>
17143e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
17153e519524SHoward Hinnanttypename enable_if
17163e519524SHoward Hinnant<
17173e519524SHoward Hinnant    is_same<typename remove_const<_Tp>::type, _Up>::value &&
1718ca740483SHoward Hinnant    is_trivially_copy_assignable<_Up>::value,
17193e519524SHoward Hinnant    _Up*
17203e519524SHoward Hinnant>::type
17213e519524SHoward Hinnant__copy(_Tp* __first, _Tp* __last, _Up* __result)
17223e519524SHoward Hinnant{
17233e519524SHoward Hinnant    const size_t __n = static_cast<size_t>(__last - __first);
17245b312052SMarshall Clow    if (__n > 0)
1725ce48a113SHoward Hinnant        _VSTD::memmove(__result, __first, __n * sizeof(_Up));
17263e519524SHoward Hinnant    return __result + __n;
17273e519524SHoward Hinnant}
17283e519524SHoward Hinnant
17293e519524SHoward Hinnanttemplate <class _InputIterator, class _OutputIterator>
173083901cbeSLouis Dionneinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17_WITH_IS_CONSTANT_EVALUATED
17313e519524SHoward Hinnant_OutputIterator
17323e519524SHoward Hinnantcopy(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
17333e519524SHoward Hinnant{
173413c90a57SLouis Dionne    if (__libcpp_is_constant_evaluated()) {
173513c90a57SLouis Dionne        return _VSTD::__copy_constexpr(
173613c90a57SLouis Dionne            __unwrap_iter(__first), __unwrap_iter(__last), __unwrap_iter(__result));
173713c90a57SLouis Dionne    } else {
173813c90a57SLouis Dionne        return _VSTD::__copy(
173913c90a57SLouis Dionne            __unwrap_iter(__first), __unwrap_iter(__last), __unwrap_iter(__result));
174013c90a57SLouis Dionne    }
17413e519524SHoward Hinnant}
17423e519524SHoward Hinnant
17433e519524SHoward Hinnant// copy_backward
17443e519524SHoward Hinnant
1745d3d4356fSHoward Hinnanttemplate <class _BidirectionalIterator, class _OutputIterator>
174613c90a57SLouis Dionneinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
174713c90a57SLouis Dionne_OutputIterator
174813c90a57SLouis Dionne__copy_backward_constexpr(_BidirectionalIterator __first, _BidirectionalIterator __last, _OutputIterator __result)
174913c90a57SLouis Dionne{
175013c90a57SLouis Dionne    while (__first != __last)
175113c90a57SLouis Dionne        *--__result = *--__last;
175213c90a57SLouis Dionne    return __result;
175313c90a57SLouis Dionne}
175413c90a57SLouis Dionne
175513c90a57SLouis Dionnetemplate <class _BidirectionalIterator, class _OutputIterator>
17563e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
17573e519524SHoward Hinnant_OutputIterator
1758d3d4356fSHoward Hinnant__copy_backward(_BidirectionalIterator __first, _BidirectionalIterator __last, _OutputIterator __result)
17593e519524SHoward Hinnant{
176013c90a57SLouis Dionne    return __copy_backward_constexpr(__first, __last, __result);
17613e519524SHoward Hinnant}
17623e519524SHoward Hinnant
17633e519524SHoward Hinnanttemplate <class _Tp, class _Up>
17643e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
17653e519524SHoward Hinnanttypename enable_if
17663e519524SHoward Hinnant<
17673e519524SHoward Hinnant    is_same<typename remove_const<_Tp>::type, _Up>::value &&
1768ca740483SHoward Hinnant    is_trivially_copy_assignable<_Up>::value,
17693e519524SHoward Hinnant    _Up*
17703e519524SHoward Hinnant>::type
17713e519524SHoward Hinnant__copy_backward(_Tp* __first, _Tp* __last, _Up* __result)
17723e519524SHoward Hinnant{
17733e519524SHoward Hinnant    const size_t __n = static_cast<size_t>(__last - __first);
17745b312052SMarshall Clow    if (__n > 0)
17755b312052SMarshall Clow    {
17763e519524SHoward Hinnant        __result -= __n;
1777ce48a113SHoward Hinnant        _VSTD::memmove(__result, __first, __n * sizeof(_Up));
17785b312052SMarshall Clow    }
17793e519524SHoward Hinnant    return __result;
17803e519524SHoward Hinnant}
17813e519524SHoward Hinnant
17823e519524SHoward Hinnanttemplate <class _BidirectionalIterator1, class _BidirectionalIterator2>
178383901cbeSLouis Dionneinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17_WITH_IS_CONSTANT_EVALUATED
17843e519524SHoward Hinnant_BidirectionalIterator2
17853e519524SHoward Hinnantcopy_backward(_BidirectionalIterator1 __first, _BidirectionalIterator1 __last,
17863e519524SHoward Hinnant              _BidirectionalIterator2 __result)
17873e519524SHoward Hinnant{
178813c90a57SLouis Dionne    if (__libcpp_is_constant_evaluated()) {
178913c90a57SLouis Dionne        return _VSTD::__copy_backward_constexpr(__unwrap_iter(__first),
179013c90a57SLouis Dionne                                                __unwrap_iter(__last),
179113c90a57SLouis Dionne                                                __unwrap_iter(__result));
179213c90a57SLouis Dionne    } else {
1793fd838227SEric Fiselier        return _VSTD::__copy_backward(__unwrap_iter(__first),
1794fd838227SEric Fiselier                                      __unwrap_iter(__last),
1795fd838227SEric Fiselier                                      __unwrap_iter(__result));
17963e519524SHoward Hinnant    }
179713c90a57SLouis Dionne}
17983e519524SHoward Hinnant
17993e519524SHoward Hinnant// copy_if
18003e519524SHoward Hinnant
18013e519524SHoward Hinnanttemplate<class _InputIterator, class _OutputIterator, class _Predicate>
180213c90a57SLouis Dionneinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
18033e519524SHoward Hinnant_OutputIterator
18043e519524SHoward Hinnantcopy_if(_InputIterator __first, _InputIterator __last,
18053e519524SHoward Hinnant        _OutputIterator __result, _Predicate __pred)
18063e519524SHoward Hinnant{
18073e519524SHoward Hinnant    for (; __first != __last; ++__first)
18083e519524SHoward Hinnant    {
18093e519524SHoward Hinnant        if (__pred(*__first))
18103e519524SHoward Hinnant        {
18113e519524SHoward Hinnant            *__result = *__first;
18123e519524SHoward Hinnant            ++__result;
18133e519524SHoward Hinnant        }
18143e519524SHoward Hinnant    }
18153e519524SHoward Hinnant    return __result;
18163e519524SHoward Hinnant}
18173e519524SHoward Hinnant
18183e519524SHoward Hinnant// copy_n
18193e519524SHoward Hinnant
18203e519524SHoward Hinnanttemplate<class _InputIterator, class _Size, class _OutputIterator>
182183901cbeSLouis Dionneinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17_WITH_IS_CONSTANT_EVALUATED
18223e519524SHoward Hinnanttypename enable_if
18233e519524SHoward Hinnant<
1824f82dba01SEric Fiselier    __is_cpp17_input_iterator<_InputIterator>::value &&
1825f82dba01SEric Fiselier   !__is_cpp17_random_access_iterator<_InputIterator>::value,
18263e519524SHoward Hinnant    _OutputIterator
18273e519524SHoward Hinnant>::type
182851544023SEric Fiseliercopy_n(_InputIterator __first, _Size __orig_n, _OutputIterator __result)
18293e519524SHoward Hinnant{
183051544023SEric Fiselier    typedef decltype(__convert_to_integral(__orig_n)) _IntegralSize;
183151544023SEric Fiselier    _IntegralSize __n = __orig_n;
183299847d2bSHoward Hinnant    if (__n > 0)
183399847d2bSHoward Hinnant    {
18343e519524SHoward Hinnant        *__result = *__first;
183599847d2bSHoward Hinnant        ++__result;
183699847d2bSHoward Hinnant        for (--__n; __n > 0; --__n)
183799847d2bSHoward Hinnant        {
183899847d2bSHoward Hinnant            ++__first;
183999847d2bSHoward Hinnant            *__result = *__first;
184099847d2bSHoward Hinnant            ++__result;
184199847d2bSHoward Hinnant        }
184299847d2bSHoward Hinnant    }
18433e519524SHoward Hinnant    return __result;
18443e519524SHoward Hinnant}
18453e519524SHoward Hinnant
18463e519524SHoward Hinnanttemplate<class _InputIterator, class _Size, class _OutputIterator>
184783901cbeSLouis Dionneinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17_WITH_IS_CONSTANT_EVALUATED
18483e519524SHoward Hinnanttypename enable_if
18493e519524SHoward Hinnant<
1850f82dba01SEric Fiselier    __is_cpp17_random_access_iterator<_InputIterator>::value,
18513e519524SHoward Hinnant    _OutputIterator
18523e519524SHoward Hinnant>::type
185351544023SEric Fiseliercopy_n(_InputIterator __first, _Size __orig_n, _OutputIterator __result)
18543e519524SHoward Hinnant{
185551544023SEric Fiselier    typedef decltype(__convert_to_integral(__orig_n)) _IntegralSize;
185651544023SEric Fiselier    _IntegralSize __n = __orig_n;
1857ce48a113SHoward Hinnant    return _VSTD::copy(__first, __first + __n, __result);
18583e519524SHoward Hinnant}
18593e519524SHoward Hinnant
18603e519524SHoward Hinnant// move
18613e519524SHoward Hinnant
1862*1ec02efeSzoecarver// __move_constexpr exists so that __move doesn't call itself when delegating to the constexpr
1863*1ec02efeSzoecarver// version of __move.
18643e519524SHoward Hinnanttemplate <class _InputIterator, class _OutputIterator>
1865*1ec02efeSzoecarverinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
18663e519524SHoward Hinnant_OutputIterator
1867*1ec02efeSzoecarver__move_constexpr(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
18683e519524SHoward Hinnant{
1869910285b2SEric Fiselier    for (; __first != __last; ++__first, (void) ++__result)
1870ce48a113SHoward Hinnant        *__result = _VSTD::move(*__first);
18713e519524SHoward Hinnant    return __result;
18723e519524SHoward Hinnant}
18733e519524SHoward Hinnant
1874*1ec02efeSzoecarvertemplate <class _InputIterator, class _OutputIterator>
1875*1ec02efeSzoecarverinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1876*1ec02efeSzoecarver_OutputIterator
1877*1ec02efeSzoecarver__move(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
1878*1ec02efeSzoecarver{
1879*1ec02efeSzoecarver    return __move_constexpr(__first, __last, __result);
1880*1ec02efeSzoecarver}
1881*1ec02efeSzoecarver
18823e519524SHoward Hinnanttemplate <class _Tp, class _Up>
1883*1ec02efeSzoecarverinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
18843e519524SHoward Hinnanttypename enable_if
18853e519524SHoward Hinnant<
18863e519524SHoward Hinnant    is_same<typename remove_const<_Tp>::type, _Up>::value &&
1887ca740483SHoward Hinnant    is_trivially_copy_assignable<_Up>::value,
18883e519524SHoward Hinnant    _Up*
18893e519524SHoward Hinnant>::type
18903e519524SHoward Hinnant__move(_Tp* __first, _Tp* __last, _Up* __result)
18913e519524SHoward Hinnant{
1892*1ec02efeSzoecarver    if (__libcpp_is_constant_evaluated())
1893*1ec02efeSzoecarver        return __move_constexpr(__first, __last, __result);
18943e519524SHoward Hinnant    const size_t __n = static_cast<size_t>(__last - __first);
18955b312052SMarshall Clow    if (__n > 0)
1896ce48a113SHoward Hinnant        _VSTD::memmove(__result, __first, __n * sizeof(_Up));
18973e519524SHoward Hinnant    return __result + __n;
18983e519524SHoward Hinnant}
18993e519524SHoward Hinnant
19003e519524SHoward Hinnanttemplate <class _InputIterator, class _OutputIterator>
1901*1ec02efeSzoecarverinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
19023e519524SHoward Hinnant_OutputIterator
19033e519524SHoward Hinnantmove(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
19043e519524SHoward Hinnant{
1905ce48a113SHoward Hinnant    return _VSTD::__move(__unwrap_iter(__first), __unwrap_iter(__last), __unwrap_iter(__result));
19063e519524SHoward Hinnant}
19073e519524SHoward Hinnant
19083e519524SHoward Hinnant// move_backward
19093e519524SHoward Hinnant
1910*1ec02efeSzoecarver// __move_backward_constexpr exists so that __move_backward doesn't call itself when delegating to
1911*1ec02efeSzoecarver// the constexpr version of __move_backward.
19123e519524SHoward Hinnanttemplate <class _InputIterator, class _OutputIterator>
1913*1ec02efeSzoecarverinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
19143e519524SHoward Hinnant_OutputIterator
1915*1ec02efeSzoecarver__move_backward_constexpr(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
19163e519524SHoward Hinnant{
19173e519524SHoward Hinnant    while (__first != __last)
1918ce48a113SHoward Hinnant        *--__result = _VSTD::move(*--__last);
19193e519524SHoward Hinnant    return __result;
19203e519524SHoward Hinnant}
19213e519524SHoward Hinnant
1922*1ec02efeSzoecarvertemplate <class _InputIterator, class _OutputIterator>
1923*1ec02efeSzoecarverinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1924*1ec02efeSzoecarver_OutputIterator
1925*1ec02efeSzoecarver__move_backward(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
1926*1ec02efeSzoecarver{
1927*1ec02efeSzoecarver    return __move_backward_constexpr(__first, __last, __result);
1928*1ec02efeSzoecarver}
1929*1ec02efeSzoecarver
19303e519524SHoward Hinnanttemplate <class _Tp, class _Up>
1931*1ec02efeSzoecarverinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
19323e519524SHoward Hinnanttypename enable_if
19333e519524SHoward Hinnant<
19343e519524SHoward Hinnant    is_same<typename remove_const<_Tp>::type, _Up>::value &&
1935ca740483SHoward Hinnant    is_trivially_copy_assignable<_Up>::value,
19363e519524SHoward Hinnant    _Up*
19373e519524SHoward Hinnant>::type
19383e519524SHoward Hinnant__move_backward(_Tp* __first, _Tp* __last, _Up* __result)
19393e519524SHoward Hinnant{
1940*1ec02efeSzoecarver    if (__libcpp_is_constant_evaluated())
1941*1ec02efeSzoecarver        return __move_backward_constexpr(__first, __last, __result);
19423e519524SHoward Hinnant    const size_t __n = static_cast<size_t>(__last - __first);
19435b312052SMarshall Clow    if (__n > 0)
19445b312052SMarshall Clow    {
19453e519524SHoward Hinnant        __result -= __n;
1946ce48a113SHoward Hinnant        _VSTD::memmove(__result, __first, __n * sizeof(_Up));
19475b312052SMarshall Clow    }
19483e519524SHoward Hinnant    return __result;
19493e519524SHoward Hinnant}
19503e519524SHoward Hinnant
19513e519524SHoward Hinnanttemplate <class _BidirectionalIterator1, class _BidirectionalIterator2>
1952*1ec02efeSzoecarverinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
19533e519524SHoward Hinnant_BidirectionalIterator2
19543e519524SHoward Hinnantmove_backward(_BidirectionalIterator1 __first, _BidirectionalIterator1 __last,
19553e519524SHoward Hinnant              _BidirectionalIterator2 __result)
19563e519524SHoward Hinnant{
1957ce48a113SHoward Hinnant    return _VSTD::__move_backward(__unwrap_iter(__first), __unwrap_iter(__last), __unwrap_iter(__result));
19583e519524SHoward Hinnant}
19593e519524SHoward Hinnant
19603e519524SHoward Hinnant// iter_swap
19613e519524SHoward Hinnant
1962a676f7d3SHoward Hinnant// moved to <type_traits> for better swap / noexcept support
19633e519524SHoward Hinnant
19643e519524SHoward Hinnant// transform
19653e519524SHoward Hinnant
19663e519524SHoward Hinnanttemplate <class _InputIterator, class _OutputIterator, class _UnaryOperation>
196799894b61SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
19683e519524SHoward Hinnant_OutputIterator
19693e519524SHoward Hinnanttransform(_InputIterator __first, _InputIterator __last, _OutputIterator __result, _UnaryOperation __op)
19703e519524SHoward Hinnant{
1971910285b2SEric Fiselier    for (; __first != __last; ++__first, (void) ++__result)
19723e519524SHoward Hinnant        *__result = __op(*__first);
19733e519524SHoward Hinnant    return __result;
19743e519524SHoward Hinnant}
19753e519524SHoward Hinnant
19763e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _BinaryOperation>
197799894b61SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
19783e519524SHoward Hinnant_OutputIterator
19793e519524SHoward Hinnanttransform(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2,
19803e519524SHoward Hinnant          _OutputIterator __result, _BinaryOperation __binary_op)
19813e519524SHoward Hinnant{
1982910285b2SEric Fiselier    for (; __first1 != __last1; ++__first1, (void) ++__first2, ++__result)
19833e519524SHoward Hinnant        *__result = __binary_op(*__first1, *__first2);
19843e519524SHoward Hinnant    return __result;
19853e519524SHoward Hinnant}
19863e519524SHoward Hinnant
19873e519524SHoward Hinnant// replace
19883e519524SHoward Hinnant
19893e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Tp>
199012c7423fSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
19913e519524SHoward Hinnantvoid
19923e519524SHoward Hinnantreplace(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __old_value, const _Tp& __new_value)
19933e519524SHoward Hinnant{
19943e519524SHoward Hinnant    for (; __first != __last; ++__first)
19953e519524SHoward Hinnant        if (*__first == __old_value)
19963e519524SHoward Hinnant            *__first = __new_value;
19973e519524SHoward Hinnant}
19983e519524SHoward Hinnant
19993e519524SHoward Hinnant// replace_if
20003e519524SHoward Hinnant
20013e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Predicate, class _Tp>
200212c7423fSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
20033e519524SHoward Hinnantvoid
20043e519524SHoward Hinnantreplace_if(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred, const _Tp& __new_value)
20053e519524SHoward Hinnant{
20063e519524SHoward Hinnant    for (; __first != __last; ++__first)
20073e519524SHoward Hinnant        if (__pred(*__first))
20083e519524SHoward Hinnant            *__first = __new_value;
20093e519524SHoward Hinnant}
20103e519524SHoward Hinnant
20113e519524SHoward Hinnant// replace_copy
20123e519524SHoward Hinnant
20133e519524SHoward Hinnanttemplate <class _InputIterator, class _OutputIterator, class _Tp>
201412c7423fSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
20153e519524SHoward Hinnant_OutputIterator
20163e519524SHoward Hinnantreplace_copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result,
20173e519524SHoward Hinnant             const _Tp& __old_value, const _Tp& __new_value)
20183e519524SHoward Hinnant{
2019910285b2SEric Fiselier    for (; __first != __last; ++__first, (void) ++__result)
20203e519524SHoward Hinnant        if (*__first == __old_value)
20213e519524SHoward Hinnant            *__result = __new_value;
20223e519524SHoward Hinnant        else
20233e519524SHoward Hinnant            *__result = *__first;
20243e519524SHoward Hinnant    return __result;
20253e519524SHoward Hinnant}
20263e519524SHoward Hinnant
20273e519524SHoward Hinnant// replace_copy_if
20283e519524SHoward Hinnant
20293e519524SHoward Hinnanttemplate <class _InputIterator, class _OutputIterator, class _Predicate, class _Tp>
203012c7423fSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
20313e519524SHoward Hinnant_OutputIterator
20323e519524SHoward Hinnantreplace_copy_if(_InputIterator __first, _InputIterator __last, _OutputIterator __result,
20333e519524SHoward Hinnant                _Predicate __pred, const _Tp& __new_value)
20343e519524SHoward Hinnant{
2035910285b2SEric Fiselier    for (; __first != __last; ++__first, (void) ++__result)
20363e519524SHoward Hinnant        if (__pred(*__first))
20373e519524SHoward Hinnant            *__result = __new_value;
20383e519524SHoward Hinnant        else
20393e519524SHoward Hinnant            *__result = *__first;
20403e519524SHoward Hinnant    return __result;
20413e519524SHoward Hinnant}
20423e519524SHoward Hinnant
20433e519524SHoward Hinnant// fill_n
20443e519524SHoward Hinnant
20453e519524SHoward Hinnanttemplate <class _OutputIterator, class _Size, class _Tp>
20464bfb9313SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
20473e519524SHoward Hinnant_OutputIterator
20480f242beaSHoward Hinnant__fill_n(_OutputIterator __first, _Size __n, const _Tp& __value_)
20493e519524SHoward Hinnant{
2050910285b2SEric Fiselier    for (; __n > 0; ++__first, (void) --__n)
2051e4383379SHoward Hinnant        *__first = __value_;
20523e519524SHoward Hinnant    return __first;
20533e519524SHoward Hinnant}
20543e519524SHoward Hinnant
20553e519524SHoward Hinnanttemplate <class _OutputIterator, class _Size, class _Tp>
20564bfb9313SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
20573e519524SHoward Hinnant_OutputIterator
2058e4383379SHoward Hinnantfill_n(_OutputIterator __first, _Size __n, const _Tp& __value_)
20593e519524SHoward Hinnant{
206051544023SEric Fiselier   return _VSTD::__fill_n(__first, __convert_to_integral(__n), __value_);
20613e519524SHoward Hinnant}
20623e519524SHoward Hinnant
20633e519524SHoward Hinnant// fill
20643e519524SHoward Hinnant
20653e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Tp>
20664bfb9313SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
20673e519524SHoward Hinnantvoid
2068e4383379SHoward Hinnant__fill(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, forward_iterator_tag)
20693e519524SHoward Hinnant{
20703e519524SHoward Hinnant    for (; __first != __last; ++__first)
2071e4383379SHoward Hinnant        *__first = __value_;
20723e519524SHoward Hinnant}
20733e519524SHoward Hinnant
20743e519524SHoward Hinnanttemplate <class _RandomAccessIterator, class _Tp>
20754bfb9313SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
20763e519524SHoward Hinnantvoid
2077e4383379SHoward Hinnant__fill(_RandomAccessIterator __first, _RandomAccessIterator __last, const _Tp& __value_, random_access_iterator_tag)
20783e519524SHoward Hinnant{
2079e4383379SHoward Hinnant    _VSTD::fill_n(__first, __last - __first, __value_);
20803e519524SHoward Hinnant}
20813e519524SHoward Hinnant
20823e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Tp>
20834bfb9313SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
20843e519524SHoward Hinnantvoid
2085e4383379SHoward Hinnantfill(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_)
20863e519524SHoward Hinnant{
2087e4383379SHoward Hinnant    _VSTD::__fill(__first, __last, __value_, typename iterator_traits<_ForwardIterator>::iterator_category());
20883e519524SHoward Hinnant}
20893e519524SHoward Hinnant
20903e519524SHoward Hinnant// generate
20913e519524SHoward Hinnant
20923e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Generator>
20934bfb9313SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
20943e519524SHoward Hinnantvoid
20953e519524SHoward Hinnantgenerate(_ForwardIterator __first, _ForwardIterator __last, _Generator __gen)
20963e519524SHoward Hinnant{
20973e519524SHoward Hinnant    for (; __first != __last; ++__first)
20983e519524SHoward Hinnant        *__first = __gen();
20993e519524SHoward Hinnant}
21003e519524SHoward Hinnant
21013e519524SHoward Hinnant// generate_n
21023e519524SHoward Hinnant
21033e519524SHoward Hinnanttemplate <class _OutputIterator, class _Size, class _Generator>
21044bfb9313SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
21053e519524SHoward Hinnant_OutputIterator
210651544023SEric Fiseliergenerate_n(_OutputIterator __first, _Size __orig_n, _Generator __gen)
21073e519524SHoward Hinnant{
210851544023SEric Fiselier    typedef decltype(__convert_to_integral(__orig_n)) _IntegralSize;
210951544023SEric Fiselier    _IntegralSize __n = __orig_n;
2110910285b2SEric Fiselier    for (; __n > 0; ++__first, (void) --__n)
21113e519524SHoward Hinnant        *__first = __gen();
21123e519524SHoward Hinnant    return __first;
21133e519524SHoward Hinnant}
21143e519524SHoward Hinnant
21153e519524SHoward Hinnant// remove
21163e519524SHoward Hinnant
21173e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Tp>
21181362d7efSNico Weber_LIBCPP_NODISCARD_EXT _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
2119e4383379SHoward Hinnantremove(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_)
21203e519524SHoward Hinnant{
2121e4383379SHoward Hinnant    __first = _VSTD::find(__first, __last, __value_);
21223e519524SHoward Hinnant    if (__first != __last)
21233e519524SHoward Hinnant    {
21243e519524SHoward Hinnant        _ForwardIterator __i = __first;
21253e519524SHoward Hinnant        while (++__i != __last)
21263e519524SHoward Hinnant        {
2127e4383379SHoward Hinnant            if (!(*__i == __value_))
21283e519524SHoward Hinnant            {
2129ce48a113SHoward Hinnant                *__first = _VSTD::move(*__i);
21303e519524SHoward Hinnant                ++__first;
21313e519524SHoward Hinnant            }
21323e519524SHoward Hinnant        }
21333e519524SHoward Hinnant    }
21343e519524SHoward Hinnant    return __first;
21353e519524SHoward Hinnant}
21363e519524SHoward Hinnant
21373e519524SHoward Hinnant// remove_if
21383e519524SHoward Hinnant
21393e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Predicate>
21401362d7efSNico Weber_LIBCPP_NODISCARD_EXT _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
21413e519524SHoward Hinnantremove_if(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred)
21423e519524SHoward Hinnant{
2143ce48a113SHoward Hinnant    __first = _VSTD::find_if<_ForwardIterator, typename add_lvalue_reference<_Predicate>::type>
21443e519524SHoward Hinnant                           (__first, __last, __pred);
21453e519524SHoward Hinnant    if (__first != __last)
21463e519524SHoward Hinnant    {
21473e519524SHoward Hinnant        _ForwardIterator __i = __first;
21483e519524SHoward Hinnant        while (++__i != __last)
21493e519524SHoward Hinnant        {
21503e519524SHoward Hinnant            if (!__pred(*__i))
21513e519524SHoward Hinnant            {
2152ce48a113SHoward Hinnant                *__first = _VSTD::move(*__i);
21533e519524SHoward Hinnant                ++__first;
21543e519524SHoward Hinnant            }
21553e519524SHoward Hinnant        }
21563e519524SHoward Hinnant    }
21573e519524SHoward Hinnant    return __first;
21583e519524SHoward Hinnant}
21593e519524SHoward Hinnant
21603e519524SHoward Hinnant// remove_copy
21613e519524SHoward Hinnant
21623e519524SHoward Hinnanttemplate <class _InputIterator, class _OutputIterator, class _Tp>
2163e8ea8296SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
21643e519524SHoward Hinnant_OutputIterator
2165e4383379SHoward Hinnantremove_copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result, const _Tp& __value_)
21663e519524SHoward Hinnant{
21673e519524SHoward Hinnant    for (; __first != __last; ++__first)
21683e519524SHoward Hinnant    {
2169e4383379SHoward Hinnant        if (!(*__first == __value_))
21703e519524SHoward Hinnant        {
21713e519524SHoward Hinnant            *__result = *__first;
21723e519524SHoward Hinnant            ++__result;
21733e519524SHoward Hinnant        }
21743e519524SHoward Hinnant    }
21753e519524SHoward Hinnant    return __result;
21763e519524SHoward Hinnant}
21773e519524SHoward Hinnant
21783e519524SHoward Hinnant// remove_copy_if
21793e519524SHoward Hinnant
21803e519524SHoward Hinnanttemplate <class _InputIterator, class _OutputIterator, class _Predicate>
2181e8ea8296SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
21823e519524SHoward Hinnant_OutputIterator
21833e519524SHoward Hinnantremove_copy_if(_InputIterator __first, _InputIterator __last, _OutputIterator __result, _Predicate __pred)
21843e519524SHoward Hinnant{
21853e519524SHoward Hinnant    for (; __first != __last; ++__first)
21863e519524SHoward Hinnant    {
21873e519524SHoward Hinnant        if (!__pred(*__first))
21883e519524SHoward Hinnant        {
21893e519524SHoward Hinnant            *__result = *__first;
21903e519524SHoward Hinnant            ++__result;
21913e519524SHoward Hinnant        }
21923e519524SHoward Hinnant    }
21933e519524SHoward Hinnant    return __result;
21943e519524SHoward Hinnant}
21953e519524SHoward Hinnant
21963e519524SHoward Hinnant// unique
21973e519524SHoward Hinnant
21983e519524SHoward Hinnanttemplate <class _ForwardIterator, class _BinaryPredicate>
21991362d7efSNico Weber_LIBCPP_NODISCARD_EXT _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
22003e519524SHoward Hinnantunique(_ForwardIterator __first, _ForwardIterator __last, _BinaryPredicate __pred)
22013e519524SHoward Hinnant{
2202ce48a113SHoward Hinnant    __first = _VSTD::adjacent_find<_ForwardIterator, typename add_lvalue_reference<_BinaryPredicate>::type>
22033e519524SHoward Hinnant                                 (__first, __last, __pred);
22043e519524SHoward Hinnant    if (__first != __last)
22053e519524SHoward Hinnant    {
22063e519524SHoward Hinnant        // ...  a  a  ?  ...
22073e519524SHoward Hinnant        //      f     i
22083e519524SHoward Hinnant        _ForwardIterator __i = __first;
22093e519524SHoward Hinnant        for (++__i; ++__i != __last;)
22103e519524SHoward Hinnant            if (!__pred(*__first, *__i))
2211ce48a113SHoward Hinnant                *++__first = _VSTD::move(*__i);
22123e519524SHoward Hinnant        ++__first;
22133e519524SHoward Hinnant    }
22143e519524SHoward Hinnant    return __first;
22153e519524SHoward Hinnant}
22163e519524SHoward Hinnant
22173e519524SHoward Hinnanttemplate <class _ForwardIterator>
22181362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
22191362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
22203e519524SHoward Hinnant_ForwardIterator
22213e519524SHoward Hinnantunique(_ForwardIterator __first, _ForwardIterator __last)
22223e519524SHoward Hinnant{
22233e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator>::value_type __v;
2224ce48a113SHoward Hinnant    return _VSTD::unique(__first, __last, __equal_to<__v>());
22253e519524SHoward Hinnant}
22263e519524SHoward Hinnant
22273e519524SHoward Hinnant// unique_copy
22283e519524SHoward Hinnant
22293e519524SHoward Hinnanttemplate <class _BinaryPredicate, class _InputIterator, class _OutputIterator>
22304bfb9313SMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 _OutputIterator
22313e519524SHoward Hinnant__unique_copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result, _BinaryPredicate __pred,
22323e519524SHoward Hinnant              input_iterator_tag, output_iterator_tag)
22333e519524SHoward Hinnant{
22343e519524SHoward Hinnant    if (__first != __last)
22353e519524SHoward Hinnant    {
22363e519524SHoward Hinnant        typename iterator_traits<_InputIterator>::value_type __t(*__first);
22373e519524SHoward Hinnant        *__result = __t;
22383e519524SHoward Hinnant        ++__result;
22393e519524SHoward Hinnant        while (++__first != __last)
22403e519524SHoward Hinnant        {
22413e519524SHoward Hinnant            if (!__pred(__t, *__first))
22423e519524SHoward Hinnant            {
22433e519524SHoward Hinnant                __t = *__first;
22443e519524SHoward Hinnant                *__result = __t;
22453e519524SHoward Hinnant                ++__result;
22463e519524SHoward Hinnant            }
22473e519524SHoward Hinnant        }
22483e519524SHoward Hinnant    }
22493e519524SHoward Hinnant    return __result;
22503e519524SHoward Hinnant}
22513e519524SHoward Hinnant
22523e519524SHoward Hinnanttemplate <class _BinaryPredicate, class _ForwardIterator, class _OutputIterator>
22534bfb9313SMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 _OutputIterator
22543e519524SHoward Hinnant__unique_copy(_ForwardIterator __first, _ForwardIterator __last, _OutputIterator __result, _BinaryPredicate __pred,
22553e519524SHoward Hinnant              forward_iterator_tag, output_iterator_tag)
22563e519524SHoward Hinnant{
22573e519524SHoward Hinnant    if (__first != __last)
22583e519524SHoward Hinnant    {
22593e519524SHoward Hinnant        _ForwardIterator __i = __first;
22603e519524SHoward Hinnant        *__result = *__i;
22613e519524SHoward Hinnant        ++__result;
22623e519524SHoward Hinnant        while (++__first != __last)
22633e519524SHoward Hinnant        {
22643e519524SHoward Hinnant            if (!__pred(*__i, *__first))
22653e519524SHoward Hinnant            {
22663e519524SHoward Hinnant                *__result = *__first;
22673e519524SHoward Hinnant                ++__result;
22683e519524SHoward Hinnant                __i = __first;
22693e519524SHoward Hinnant            }
22703e519524SHoward Hinnant        }
22713e519524SHoward Hinnant    }
22723e519524SHoward Hinnant    return __result;
22733e519524SHoward Hinnant}
22743e519524SHoward Hinnant
22753e519524SHoward Hinnanttemplate <class _BinaryPredicate, class _InputIterator, class _ForwardIterator>
22764bfb9313SMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
22773e519524SHoward Hinnant__unique_copy(_InputIterator __first, _InputIterator __last, _ForwardIterator __result, _BinaryPredicate __pred,
22783e519524SHoward Hinnant              input_iterator_tag, forward_iterator_tag)
22793e519524SHoward Hinnant{
22803e519524SHoward Hinnant    if (__first != __last)
22813e519524SHoward Hinnant    {
22823e519524SHoward Hinnant        *__result = *__first;
22833e519524SHoward Hinnant        while (++__first != __last)
22843e519524SHoward Hinnant            if (!__pred(*__result, *__first))
22853e519524SHoward Hinnant                *++__result = *__first;
22863e519524SHoward Hinnant        ++__result;
22873e519524SHoward Hinnant    }
22883e519524SHoward Hinnant    return __result;
22893e519524SHoward Hinnant}
22903e519524SHoward Hinnant
22913e519524SHoward Hinnanttemplate <class _InputIterator, class _OutputIterator, class _BinaryPredicate>
22924bfb9313SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
22933e519524SHoward Hinnant_OutputIterator
22943e519524SHoward Hinnantunique_copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result, _BinaryPredicate __pred)
22953e519524SHoward Hinnant{
2296ce48a113SHoward Hinnant    return _VSTD::__unique_copy<typename add_lvalue_reference<_BinaryPredicate>::type>
22973e519524SHoward Hinnant                              (__first, __last, __result, __pred,
22983e519524SHoward Hinnant                               typename iterator_traits<_InputIterator>::iterator_category(),
22993e519524SHoward Hinnant                               typename iterator_traits<_OutputIterator>::iterator_category());
23003e519524SHoward Hinnant}
23013e519524SHoward Hinnant
23023e519524SHoward Hinnanttemplate <class _InputIterator, class _OutputIterator>
23034bfb9313SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
23043e519524SHoward Hinnant_OutputIterator
23053e519524SHoward Hinnantunique_copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
23063e519524SHoward Hinnant{
23073e519524SHoward Hinnant    typedef typename iterator_traits<_InputIterator>::value_type __v;
2308ce48a113SHoward Hinnant    return _VSTD::unique_copy(__first, __last, __result, __equal_to<__v>());
23093e519524SHoward Hinnant}
23103e519524SHoward Hinnant
23113e519524SHoward Hinnant// reverse
23123e519524SHoward Hinnant
23133e519524SHoward Hinnanttemplate <class _BidirectionalIterator>
23143e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
23153e519524SHoward Hinnantvoid
23163e519524SHoward Hinnant__reverse(_BidirectionalIterator __first, _BidirectionalIterator __last, bidirectional_iterator_tag)
23173e519524SHoward Hinnant{
23183e519524SHoward Hinnant    while (__first != __last)
23193e519524SHoward Hinnant    {
23203e519524SHoward Hinnant        if (__first == --__last)
23213e519524SHoward Hinnant            break;
2322def501d1SMarshall Clow        _VSTD::iter_swap(__first, __last);
23233e519524SHoward Hinnant        ++__first;
23243e519524SHoward Hinnant    }
23253e519524SHoward Hinnant}
23263e519524SHoward Hinnant
23273e519524SHoward Hinnanttemplate <class _RandomAccessIterator>
23283e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
23293e519524SHoward Hinnantvoid
23303e519524SHoward Hinnant__reverse(_RandomAccessIterator __first, _RandomAccessIterator __last, random_access_iterator_tag)
23313e519524SHoward Hinnant{
23323e519524SHoward Hinnant    if (__first != __last)
23333e519524SHoward Hinnant        for (; __first < --__last; ++__first)
2334def501d1SMarshall Clow            _VSTD::iter_swap(__first, __last);
23353e519524SHoward Hinnant}
23363e519524SHoward Hinnant
23373e519524SHoward Hinnanttemplate <class _BidirectionalIterator>
23383e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
23393e519524SHoward Hinnantvoid
23403e519524SHoward Hinnantreverse(_BidirectionalIterator __first, _BidirectionalIterator __last)
23413e519524SHoward Hinnant{
2342ce48a113SHoward Hinnant    _VSTD::__reverse(__first, __last, typename iterator_traits<_BidirectionalIterator>::iterator_category());
23433e519524SHoward Hinnant}
23443e519524SHoward Hinnant
23453e519524SHoward Hinnant// reverse_copy
23463e519524SHoward Hinnant
23473e519524SHoward Hinnanttemplate <class _BidirectionalIterator, class _OutputIterator>
2348e8ea8296SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
23493e519524SHoward Hinnant_OutputIterator
23503e519524SHoward Hinnantreverse_copy(_BidirectionalIterator __first, _BidirectionalIterator __last, _OutputIterator __result)
23513e519524SHoward Hinnant{
23523e519524SHoward Hinnant    for (; __first != __last; ++__result)
23533e519524SHoward Hinnant        *__result = *--__last;
23543e519524SHoward Hinnant    return __result;
23553e519524SHoward Hinnant}
23563e519524SHoward Hinnant
23573e519524SHoward Hinnant// rotate
23583e519524SHoward Hinnant
23593e519524SHoward Hinnanttemplate <class _ForwardIterator>
2360*1ec02efeSzoecarver_LIBCPP_CONSTEXPR_AFTER_CXX11 _ForwardIterator
2361aca09de3SHoward Hinnant__rotate_left(_ForwardIterator __first, _ForwardIterator __last)
23623e519524SHoward Hinnant{
2363aca09de3SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
2364aca09de3SHoward Hinnant    value_type __tmp = _VSTD::move(*__first);
2365aca09de3SHoward Hinnant    _ForwardIterator __lm1 = _VSTD::move(_VSTD::next(__first), __last, __first);
2366aca09de3SHoward Hinnant    *__lm1 = _VSTD::move(__tmp);
2367aca09de3SHoward Hinnant    return __lm1;
2368aca09de3SHoward Hinnant}
2369aca09de3SHoward Hinnant
2370aca09de3SHoward Hinnanttemplate <class _BidirectionalIterator>
2371*1ec02efeSzoecarver_LIBCPP_CONSTEXPR_AFTER_CXX11 _BidirectionalIterator
2372aca09de3SHoward Hinnant__rotate_right(_BidirectionalIterator __first, _BidirectionalIterator __last)
2373aca09de3SHoward Hinnant{
2374aca09de3SHoward Hinnant    typedef typename iterator_traits<_BidirectionalIterator>::value_type value_type;
2375aca09de3SHoward Hinnant    _BidirectionalIterator __lm1 = _VSTD::prev(__last);
2376aca09de3SHoward Hinnant    value_type __tmp = _VSTD::move(*__lm1);
2377aca09de3SHoward Hinnant    _BidirectionalIterator __fp1 = _VSTD::move_backward(__first, __lm1, __last);
2378aca09de3SHoward Hinnant    *__first = _VSTD::move(__tmp);
2379aca09de3SHoward Hinnant    return __fp1;
2380aca09de3SHoward Hinnant}
2381aca09de3SHoward Hinnant
2382aca09de3SHoward Hinnanttemplate <class _ForwardIterator>
2383*1ec02efeSzoecarver_LIBCPP_CONSTEXPR_AFTER_CXX14 _ForwardIterator
2384aca09de3SHoward Hinnant__rotate_forward(_ForwardIterator __first, _ForwardIterator __middle, _ForwardIterator __last)
2385aca09de3SHoward Hinnant{
23863e519524SHoward Hinnant    _ForwardIterator __i = __middle;
23873e519524SHoward Hinnant    while (true)
23883e519524SHoward Hinnant    {
23893e519524SHoward Hinnant        swap(*__first, *__i);
23903e519524SHoward Hinnant        ++__first;
23913e519524SHoward Hinnant        if (++__i == __last)
23923e519524SHoward Hinnant            break;
23933e519524SHoward Hinnant        if (__first == __middle)
23943e519524SHoward Hinnant            __middle = __i;
23953e519524SHoward Hinnant    }
23963e519524SHoward Hinnant    _ForwardIterator __r = __first;
23973e519524SHoward Hinnant    if (__first != __middle)
23983e519524SHoward Hinnant    {
23993e519524SHoward Hinnant        __i = __middle;
24003e519524SHoward Hinnant        while (true)
24013e519524SHoward Hinnant        {
24023e519524SHoward Hinnant            swap(*__first, *__i);
24033e519524SHoward Hinnant            ++__first;
24043e519524SHoward Hinnant            if (++__i == __last)
24053e519524SHoward Hinnant            {
24063e519524SHoward Hinnant                if (__first == __middle)
24073e519524SHoward Hinnant                    break;
24083e519524SHoward Hinnant                __i = __middle;
24093e519524SHoward Hinnant            }
24103e519524SHoward Hinnant            else if (__first == __middle)
24113e519524SHoward Hinnant                __middle = __i;
24123e519524SHoward Hinnant        }
24133e519524SHoward Hinnant    }
24143e519524SHoward Hinnant    return __r;
24153e519524SHoward Hinnant}
24163e519524SHoward Hinnant
24173e519524SHoward Hinnanttemplate<typename _Integral>
24183e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
2419*1ec02efeSzoecarver_LIBCPP_CONSTEXPR_AFTER_CXX14 _Integral
242019b4035fSMarshall Clow__algo_gcd(_Integral __x, _Integral __y)
24213e519524SHoward Hinnant{
24223e519524SHoward Hinnant    do
24233e519524SHoward Hinnant    {
24243e519524SHoward Hinnant        _Integral __t = __x % __y;
24253e519524SHoward Hinnant        __x = __y;
24263e519524SHoward Hinnant        __y = __t;
24273e519524SHoward Hinnant    } while (__y);
24283e519524SHoward Hinnant    return __x;
24293e519524SHoward Hinnant}
24303e519524SHoward Hinnant
24313e519524SHoward Hinnanttemplate<typename _RandomAccessIterator>
2432*1ec02efeSzoecarver_LIBCPP_CONSTEXPR_AFTER_CXX14 _RandomAccessIterator
2433aca09de3SHoward Hinnant__rotate_gcd(_RandomAccessIterator __first, _RandomAccessIterator __middle, _RandomAccessIterator __last)
24343e519524SHoward Hinnant{
24353e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
24363e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
24373e519524SHoward Hinnant
24383e519524SHoward Hinnant    const difference_type __m1 = __middle - __first;
24393e519524SHoward Hinnant    const difference_type __m2 = __last - __middle;
24403e519524SHoward Hinnant    if (__m1 == __m2)
24413e519524SHoward Hinnant    {
2442ce48a113SHoward Hinnant        _VSTD::swap_ranges(__first, __middle, __middle);
24433e519524SHoward Hinnant        return __middle;
24443e519524SHoward Hinnant    }
244519b4035fSMarshall Clow    const difference_type __g = _VSTD::__algo_gcd(__m1, __m2);
24463e519524SHoward Hinnant    for (_RandomAccessIterator __p = __first + __g; __p != __first;)
24473e519524SHoward Hinnant    {
2448aca09de3SHoward Hinnant        value_type __t(_VSTD::move(*--__p));
24493e519524SHoward Hinnant        _RandomAccessIterator __p1 = __p;
24503e519524SHoward Hinnant        _RandomAccessIterator __p2 = __p1 + __m1;
24513e519524SHoward Hinnant        do
24523e519524SHoward Hinnant        {
2453aca09de3SHoward Hinnant            *__p1 = _VSTD::move(*__p2);
24543e519524SHoward Hinnant            __p1 = __p2;
24553e519524SHoward Hinnant            const difference_type __d = __last - __p2;
24563e519524SHoward Hinnant            if (__m1 < __d)
24573e519524SHoward Hinnant                __p2 += __m1;
24583e519524SHoward Hinnant            else
24593e519524SHoward Hinnant                __p2 = __first + (__m1 - __d);
24603e519524SHoward Hinnant        } while (__p2 != __p);
2461aca09de3SHoward Hinnant        *__p1 = _VSTD::move(__t);
24623e519524SHoward Hinnant    }
24633e519524SHoward Hinnant    return __first + __m2;
24643e519524SHoward Hinnant}
24653e519524SHoward Hinnant
24663e519524SHoward Hinnanttemplate <class _ForwardIterator>
24673e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
2468*1ec02efeSzoecarver_LIBCPP_CONSTEXPR_AFTER_CXX11 _ForwardIterator
2469aca09de3SHoward Hinnant__rotate(_ForwardIterator __first, _ForwardIterator __middle, _ForwardIterator __last,
2470aca09de3SHoward Hinnant         _VSTD::forward_iterator_tag)
2471aca09de3SHoward Hinnant{
2472aca09de3SHoward Hinnant    typedef typename _VSTD::iterator_traits<_ForwardIterator>::value_type value_type;
2473aca09de3SHoward Hinnant    if (_VSTD::is_trivially_move_assignable<value_type>::value)
2474aca09de3SHoward Hinnant    {
2475aca09de3SHoward Hinnant        if (_VSTD::next(__first) == __middle)
2476aca09de3SHoward Hinnant            return _VSTD::__rotate_left(__first, __last);
2477aca09de3SHoward Hinnant    }
2478aca09de3SHoward Hinnant    return _VSTD::__rotate_forward(__first, __middle, __last);
2479aca09de3SHoward Hinnant}
2480aca09de3SHoward Hinnant
2481aca09de3SHoward Hinnanttemplate <class _BidirectionalIterator>
2482aca09de3SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
2483*1ec02efeSzoecarver_LIBCPP_CONSTEXPR_AFTER_CXX11 _BidirectionalIterator
2484aca09de3SHoward Hinnant__rotate(_BidirectionalIterator __first, _BidirectionalIterator __middle, _BidirectionalIterator __last,
2485aca09de3SHoward Hinnant         _VSTD::bidirectional_iterator_tag)
2486aca09de3SHoward Hinnant{
2487aca09de3SHoward Hinnant    typedef typename _VSTD::iterator_traits<_BidirectionalIterator>::value_type value_type;
2488aca09de3SHoward Hinnant    if (_VSTD::is_trivially_move_assignable<value_type>::value)
2489aca09de3SHoward Hinnant    {
2490aca09de3SHoward Hinnant        if (_VSTD::next(__first) == __middle)
2491aca09de3SHoward Hinnant            return _VSTD::__rotate_left(__first, __last);
2492aca09de3SHoward Hinnant        if (_VSTD::next(__middle) == __last)
2493aca09de3SHoward Hinnant            return _VSTD::__rotate_right(__first, __last);
2494aca09de3SHoward Hinnant    }
2495aca09de3SHoward Hinnant    return _VSTD::__rotate_forward(__first, __middle, __last);
2496aca09de3SHoward Hinnant}
2497aca09de3SHoward Hinnant
2498aca09de3SHoward Hinnanttemplate <class _RandomAccessIterator>
2499aca09de3SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
2500*1ec02efeSzoecarver_LIBCPP_CONSTEXPR_AFTER_CXX11 _RandomAccessIterator
2501aca09de3SHoward Hinnant__rotate(_RandomAccessIterator __first, _RandomAccessIterator __middle, _RandomAccessIterator __last,
2502aca09de3SHoward Hinnant         _VSTD::random_access_iterator_tag)
2503aca09de3SHoward Hinnant{
2504aca09de3SHoward Hinnant    typedef typename _VSTD::iterator_traits<_RandomAccessIterator>::value_type value_type;
2505aca09de3SHoward Hinnant    if (_VSTD::is_trivially_move_assignable<value_type>::value)
2506aca09de3SHoward Hinnant    {
2507aca09de3SHoward Hinnant        if (_VSTD::next(__first) == __middle)
2508aca09de3SHoward Hinnant            return _VSTD::__rotate_left(__first, __last);
2509aca09de3SHoward Hinnant        if (_VSTD::next(__middle) == __last)
2510aca09de3SHoward Hinnant            return _VSTD::__rotate_right(__first, __last);
2511aca09de3SHoward Hinnant        return _VSTD::__rotate_gcd(__first, __middle, __last);
2512aca09de3SHoward Hinnant    }
2513aca09de3SHoward Hinnant    return _VSTD::__rotate_forward(__first, __middle, __last);
2514aca09de3SHoward Hinnant}
2515aca09de3SHoward Hinnant
2516aca09de3SHoward Hinnanttemplate <class _ForwardIterator>
2517aca09de3SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
2518*1ec02efeSzoecarver_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
25193e519524SHoward Hinnantrotate(_ForwardIterator __first, _ForwardIterator __middle, _ForwardIterator __last)
25203e519524SHoward Hinnant{
2521aca09de3SHoward Hinnant    if (__first == __middle)
2522aca09de3SHoward Hinnant        return __last;
2523aca09de3SHoward Hinnant    if (__middle == __last)
2524aca09de3SHoward Hinnant        return __first;
2525ce48a113SHoward Hinnant    return _VSTD::__rotate(__first, __middle, __last,
2526aca09de3SHoward Hinnant                           typename _VSTD::iterator_traits<_ForwardIterator>::iterator_category());
25273e519524SHoward Hinnant}
25283e519524SHoward Hinnant
25293e519524SHoward Hinnant// rotate_copy
25303e519524SHoward Hinnant
25313e519524SHoward Hinnanttemplate <class _ForwardIterator, class _OutputIterator>
25323e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
25333e519524SHoward Hinnant_OutputIterator
25343e519524SHoward Hinnantrotate_copy(_ForwardIterator __first, _ForwardIterator __middle, _ForwardIterator __last, _OutputIterator __result)
25353e519524SHoward Hinnant{
2536ce48a113SHoward Hinnant    return _VSTD::copy(__first, __middle, _VSTD::copy(__middle, __last, __result));
25373e519524SHoward Hinnant}
25383e519524SHoward Hinnant
25393e519524SHoward Hinnant// min_element
25403e519524SHoward Hinnant
25413e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Compare>
25421362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
25431362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
25443e519524SHoward Hinnant_ForwardIterator
25450b0671aeSMarshall Clowmin_element(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp)
25463e519524SHoward Hinnant{
2547f82dba01SEric Fiselier    static_assert(__is_cpp17_forward_iterator<_ForwardIterator>::value,
2548a60d7facSEric Fiselier        "std::min_element requires a ForwardIterator");
25493e519524SHoward Hinnant    if (__first != __last)
25503e519524SHoward Hinnant    {
25513e519524SHoward Hinnant        _ForwardIterator __i = __first;
25523e519524SHoward Hinnant        while (++__i != __last)
25533e519524SHoward Hinnant            if (__comp(*__i, *__first))
25543e519524SHoward Hinnant                __first = __i;
25553e519524SHoward Hinnant    }
25563e519524SHoward Hinnant    return __first;
25573e519524SHoward Hinnant}
25583e519524SHoward Hinnant
25593e519524SHoward Hinnanttemplate <class _ForwardIterator>
25601362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
25611362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
25623e519524SHoward Hinnant_ForwardIterator
25633e519524SHoward Hinnantmin_element(_ForwardIterator __first, _ForwardIterator __last)
25643e519524SHoward Hinnant{
25650b0671aeSMarshall Clow    return _VSTD::min_element(__first, __last,
25664eb27b79SHoward Hinnant              __less<typename iterator_traits<_ForwardIterator>::value_type>());
25674eb27b79SHoward Hinnant}
25684eb27b79SHoward Hinnant
25694eb27b79SHoward Hinnant// min
25704eb27b79SHoward Hinnant
25714eb27b79SHoward Hinnanttemplate <class _Tp, class _Compare>
25721362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
25731362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
25744eb27b79SHoward Hinnantconst _Tp&
25754eb27b79SHoward Hinnantmin(const _Tp& __a, const _Tp& __b, _Compare __comp)
25764eb27b79SHoward Hinnant{
25774eb27b79SHoward Hinnant    return __comp(__b, __a) ? __b : __a;
25784eb27b79SHoward Hinnant}
25794eb27b79SHoward Hinnant
25804eb27b79SHoward Hinnanttemplate <class _Tp>
25811362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
25821362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
25834eb27b79SHoward Hinnantconst _Tp&
25844eb27b79SHoward Hinnantmin(const _Tp& __a, const _Tp& __b)
25854eb27b79SHoward Hinnant{
2586ce48a113SHoward Hinnant    return _VSTD::min(__a, __b, __less<_Tp>());
25874eb27b79SHoward Hinnant}
25884eb27b79SHoward Hinnant
2589ddda456aSEric Fiselier#ifndef _LIBCPP_CXX03_LANG
259054976f26SHoward Hinnant
25914eb27b79SHoward Hinnanttemplate<class _Tp, class _Compare>
25921362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
25931362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
25944eb27b79SHoward Hinnant_Tp
25954eb27b79SHoward Hinnantmin(initializer_list<_Tp> __t, _Compare __comp)
25964eb27b79SHoward Hinnant{
25970b0671aeSMarshall Clow    return *_VSTD::min_element(__t.begin(), __t.end(), __comp);
25984eb27b79SHoward Hinnant}
25994eb27b79SHoward Hinnant
26004eb27b79SHoward Hinnanttemplate<class _Tp>
26011362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
26021362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
26034eb27b79SHoward Hinnant_Tp
26044eb27b79SHoward Hinnantmin(initializer_list<_Tp> __t)
26054eb27b79SHoward Hinnant{
26060b0671aeSMarshall Clow    return *_VSTD::min_element(__t.begin(), __t.end(), __less<_Tp>());
26073e519524SHoward Hinnant}
26083e519524SHoward Hinnant
2609ddda456aSEric Fiselier#endif  // _LIBCPP_CXX03_LANG
261054976f26SHoward Hinnant
26113e519524SHoward Hinnant// max_element
26123e519524SHoward Hinnant
26133e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Compare>
26141362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
26151362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
26163e519524SHoward Hinnant_ForwardIterator
26170b0671aeSMarshall Clowmax_element(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp)
26183e519524SHoward Hinnant{
2619f82dba01SEric Fiselier    static_assert(__is_cpp17_forward_iterator<_ForwardIterator>::value,
2620a60d7facSEric Fiselier        "std::max_element requires a ForwardIterator");
26213e519524SHoward Hinnant    if (__first != __last)
26223e519524SHoward Hinnant    {
26233e519524SHoward Hinnant        _ForwardIterator __i = __first;
26243e519524SHoward Hinnant        while (++__i != __last)
26253e519524SHoward Hinnant            if (__comp(*__first, *__i))
26263e519524SHoward Hinnant                __first = __i;
26273e519524SHoward Hinnant    }
26283e519524SHoward Hinnant    return __first;
26293e519524SHoward Hinnant}
26303e519524SHoward Hinnant
26319d67c6d5SMarshall Clow
26323e519524SHoward Hinnanttemplate <class _ForwardIterator>
26331362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
26341362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
26353e519524SHoward Hinnant_ForwardIterator
26363e519524SHoward Hinnantmax_element(_ForwardIterator __first, _ForwardIterator __last)
26373e519524SHoward Hinnant{
26380b0671aeSMarshall Clow    return _VSTD::max_element(__first, __last,
26394eb27b79SHoward Hinnant              __less<typename iterator_traits<_ForwardIterator>::value_type>());
26404eb27b79SHoward Hinnant}
26414eb27b79SHoward Hinnant
26424eb27b79SHoward Hinnant// max
26434eb27b79SHoward Hinnant
26444eb27b79SHoward Hinnanttemplate <class _Tp, class _Compare>
26451362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
26461362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
26474eb27b79SHoward Hinnantconst _Tp&
26484eb27b79SHoward Hinnantmax(const _Tp& __a, const _Tp& __b, _Compare __comp)
26494eb27b79SHoward Hinnant{
26504eb27b79SHoward Hinnant    return __comp(__a, __b) ? __b : __a;
26514eb27b79SHoward Hinnant}
26524eb27b79SHoward Hinnant
26534eb27b79SHoward Hinnanttemplate <class _Tp>
26541362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
26551362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
26564eb27b79SHoward Hinnantconst _Tp&
26574eb27b79SHoward Hinnantmax(const _Tp& __a, const _Tp& __b)
26584eb27b79SHoward Hinnant{
2659ce48a113SHoward Hinnant    return _VSTD::max(__a, __b, __less<_Tp>());
26604eb27b79SHoward Hinnant}
26614eb27b79SHoward Hinnant
2662ddda456aSEric Fiselier#ifndef _LIBCPP_CXX03_LANG
266354976f26SHoward Hinnant
26644eb27b79SHoward Hinnanttemplate<class _Tp, class _Compare>
26651362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
26661362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
26674eb27b79SHoward Hinnant_Tp
26684eb27b79SHoward Hinnantmax(initializer_list<_Tp> __t, _Compare __comp)
26694eb27b79SHoward Hinnant{
26700b0671aeSMarshall Clow    return *_VSTD::max_element(__t.begin(), __t.end(), __comp);
26714eb27b79SHoward Hinnant}
26724eb27b79SHoward Hinnant
26734eb27b79SHoward Hinnanttemplate<class _Tp>
26741362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
26751362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
26764eb27b79SHoward Hinnant_Tp
26774eb27b79SHoward Hinnantmax(initializer_list<_Tp> __t)
26784eb27b79SHoward Hinnant{
26790b0671aeSMarshall Clow    return *_VSTD::max_element(__t.begin(), __t.end(), __less<_Tp>());
26803e519524SHoward Hinnant}
26813e519524SHoward Hinnant
2682ddda456aSEric Fiselier#endif  // _LIBCPP_CXX03_LANG
268354976f26SHoward Hinnant
2684146c14acSMarshall Clow#if _LIBCPP_STD_VER > 14
2685146c14acSMarshall Clow// clamp
2686146c14acSMarshall Clowtemplate<class _Tp, class _Compare>
26871362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
26881362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
2689146c14acSMarshall Clowconst _Tp&
2690146c14acSMarshall Clowclamp(const _Tp& __v, const _Tp& __lo, const _Tp& __hi, _Compare __comp)
2691146c14acSMarshall Clow{
2692146c14acSMarshall Clow    _LIBCPP_ASSERT(!__comp(__hi, __lo), "Bad bounds passed to std::clamp");
2693146c14acSMarshall Clow    return __comp(__v, __lo) ? __lo : __comp(__hi, __v) ? __hi : __v;
2694146c14acSMarshall Clow
2695146c14acSMarshall Clow}
2696146c14acSMarshall Clow
2697146c14acSMarshall Clowtemplate<class _Tp>
26981362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
26991362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
2700146c14acSMarshall Clowconst _Tp&
2701146c14acSMarshall Clowclamp(const _Tp& __v, const _Tp& __lo, const _Tp& __hi)
2702146c14acSMarshall Clow{
2703146c14acSMarshall Clow    return _VSTD::clamp(__v, __lo, __hi, __less<_Tp>());
2704146c14acSMarshall Clow}
2705146c14acSMarshall Clow#endif
2706146c14acSMarshall Clow
27073e519524SHoward Hinnant// minmax_element
27083e519524SHoward Hinnant
27093e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Compare>
27101362d7efSNico Weber_LIBCPP_NODISCARD_EXT _LIBCPP_CONSTEXPR_AFTER_CXX11
27113e519524SHoward Hinnantstd::pair<_ForwardIterator, _ForwardIterator>
27123e519524SHoward Hinnantminmax_element(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp)
27133e519524SHoward Hinnant{
2714f82dba01SEric Fiselier  static_assert(__is_cpp17_forward_iterator<_ForwardIterator>::value,
2715a60d7facSEric Fiselier        "std::minmax_element requires a ForwardIterator");
27163e519524SHoward Hinnant  std::pair<_ForwardIterator, _ForwardIterator> __result(__first, __first);
27173e519524SHoward Hinnant  if (__first != __last)
27183e519524SHoward Hinnant  {
27193e519524SHoward Hinnant      if (++__first != __last)
27203e519524SHoward Hinnant      {
27213e519524SHoward Hinnant          if (__comp(*__first, *__result.first))
27223e519524SHoward Hinnant              __result.first = __first;
27233e519524SHoward Hinnant          else
27243e519524SHoward Hinnant              __result.second = __first;
27253e519524SHoward Hinnant          while (++__first != __last)
27263e519524SHoward Hinnant          {
27273e519524SHoward Hinnant              _ForwardIterator __i = __first;
27283e519524SHoward Hinnant              if (++__first == __last)
27293e519524SHoward Hinnant              {
27303e519524SHoward Hinnant                  if (__comp(*__i, *__result.first))
27313e519524SHoward Hinnant                      __result.first = __i;
27323e519524SHoward Hinnant                  else if (!__comp(*__i, *__result.second))
27333e519524SHoward Hinnant                      __result.second = __i;
27343e519524SHoward Hinnant                  break;
27353e519524SHoward Hinnant              }
27363e519524SHoward Hinnant              else
27373e519524SHoward Hinnant              {
27383e519524SHoward Hinnant                  if (__comp(*__first, *__i))
27393e519524SHoward Hinnant                  {
27403e519524SHoward Hinnant                      if (__comp(*__first, *__result.first))
27413e519524SHoward Hinnant                          __result.first = __first;
27423e519524SHoward Hinnant                      if (!__comp(*__i, *__result.second))
27433e519524SHoward Hinnant                          __result.second = __i;
27443e519524SHoward Hinnant                  }
27453e519524SHoward Hinnant                  else
27463e519524SHoward Hinnant                  {
27473e519524SHoward Hinnant                      if (__comp(*__i, *__result.first))
27483e519524SHoward Hinnant                          __result.first = __i;
27493e519524SHoward Hinnant                      if (!__comp(*__first, *__result.second))
27503e519524SHoward Hinnant                          __result.second = __first;
27513e519524SHoward Hinnant                  }
27523e519524SHoward Hinnant              }
27533e519524SHoward Hinnant          }
27543e519524SHoward Hinnant      }
27553e519524SHoward Hinnant  }
27563e519524SHoward Hinnant  return __result;
27573e519524SHoward Hinnant}
27583e519524SHoward Hinnant
27593e519524SHoward Hinnanttemplate <class _ForwardIterator>
27601362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
27611362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
27623e519524SHoward Hinnantstd::pair<_ForwardIterator, _ForwardIterator>
27633e519524SHoward Hinnantminmax_element(_ForwardIterator __first, _ForwardIterator __last)
27643e519524SHoward Hinnant{
27659d67c6d5SMarshall Clow    return _VSTD::minmax_element(__first, __last,
27669d67c6d5SMarshall Clow              __less<typename iterator_traits<_ForwardIterator>::value_type>());
27673e519524SHoward Hinnant}
27683e519524SHoward Hinnant
27694eb27b79SHoward Hinnant// minmax
27704eb27b79SHoward Hinnant
27714eb27b79SHoward Hinnanttemplate<class _Tp, class _Compare>
27721362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
27731362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
27744eb27b79SHoward Hinnantpair<const _Tp&, const _Tp&>
27754eb27b79SHoward Hinnantminmax(const _Tp& __a, const _Tp& __b, _Compare __comp)
27764eb27b79SHoward Hinnant{
27774eb27b79SHoward Hinnant    return __comp(__b, __a) ? pair<const _Tp&, const _Tp&>(__b, __a) :
27784eb27b79SHoward Hinnant                              pair<const _Tp&, const _Tp&>(__a, __b);
27794eb27b79SHoward Hinnant}
27804eb27b79SHoward Hinnant
27814eb27b79SHoward Hinnanttemplate<class _Tp>
27821362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
27831362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
27844eb27b79SHoward Hinnantpair<const _Tp&, const _Tp&>
27854eb27b79SHoward Hinnantminmax(const _Tp& __a, const _Tp& __b)
27864eb27b79SHoward Hinnant{
2787ce48a113SHoward Hinnant    return _VSTD::minmax(__a, __b, __less<_Tp>());
27884eb27b79SHoward Hinnant}
27894eb27b79SHoward Hinnant
2790ddda456aSEric Fiselier#ifndef _LIBCPP_CXX03_LANG
279154976f26SHoward Hinnant
27924eb27b79SHoward Hinnanttemplate<class _Tp, class _Compare>
27931362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
27941362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
27954eb27b79SHoward Hinnantpair<_Tp, _Tp>
27964eb27b79SHoward Hinnantminmax(initializer_list<_Tp> __t, _Compare __comp)
27974eb27b79SHoward Hinnant{
27989d67c6d5SMarshall Clow    typedef typename initializer_list<_Tp>::const_iterator _Iter;
27999d67c6d5SMarshall Clow    _Iter __first = __t.begin();
28009d67c6d5SMarshall Clow    _Iter __last  = __t.end();
28019d67c6d5SMarshall Clow    std::pair<_Tp, _Tp> __result(*__first, *__first);
28029d67c6d5SMarshall Clow
28039d67c6d5SMarshall Clow    ++__first;
28049d67c6d5SMarshall Clow    if (__t.size() % 2 == 0)
28059d67c6d5SMarshall Clow    {
28069d67c6d5SMarshall Clow        if (__comp(*__first,  __result.first))
28079d67c6d5SMarshall Clow            __result.first  = *__first;
28089d67c6d5SMarshall Clow        else
28099d67c6d5SMarshall Clow            __result.second = *__first;
28109d67c6d5SMarshall Clow        ++__first;
28119d67c6d5SMarshall Clow    }
28129d67c6d5SMarshall Clow
28139d67c6d5SMarshall Clow    while (__first != __last)
28149d67c6d5SMarshall Clow    {
28159d67c6d5SMarshall Clow        _Tp __prev = *__first++;
2816002144f6SMarshall Clow        if (__comp(*__first, __prev)) {
2817002144f6SMarshall Clow            if ( __comp(*__first, __result.first)) __result.first  = *__first;
2818002144f6SMarshall Clow            if (!__comp(__prev, __result.second))  __result.second = __prev;
28199d67c6d5SMarshall Clow            }
28209d67c6d5SMarshall Clow        else {
2821002144f6SMarshall Clow            if ( __comp(__prev, __result.first))    __result.first  = __prev;
2822002144f6SMarshall Clow            if (!__comp(*__first, __result.second)) __result.second = *__first;
28239d67c6d5SMarshall Clow            }
28249d67c6d5SMarshall Clow
28259d67c6d5SMarshall Clow        __first++;
28269d67c6d5SMarshall Clow    }
28279d67c6d5SMarshall Clow    return __result;
28289d67c6d5SMarshall Clow}
28299d67c6d5SMarshall Clow
28309d67c6d5SMarshall Clowtemplate<class _Tp>
28311362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
28321362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
28339d67c6d5SMarshall Clowpair<_Tp, _Tp>
28349d67c6d5SMarshall Clowminmax(initializer_list<_Tp> __t)
28359d67c6d5SMarshall Clow{
28369d67c6d5SMarshall Clow    return _VSTD::minmax(__t, __less<_Tp>());
28374eb27b79SHoward Hinnant}
28384eb27b79SHoward Hinnant
2839ddda456aSEric Fiselier#endif  // _LIBCPP_CXX03_LANG
284054976f26SHoward Hinnant
28413e519524SHoward Hinnant// random_shuffle
28423e519524SHoward Hinnant
2843f9d540b0SHoward Hinnant// __independent_bits_engine
2844f9d540b0SHoward Hinnant
2845c003db1fSHoward Hinnanttemplate <unsigned long long _Xp, size_t _Rp>
2846f9d540b0SHoward Hinnantstruct __log2_imp
28473e519524SHoward Hinnant{
2848c003db1fSHoward Hinnant    static const size_t value = _Xp & ((unsigned long long)(1) << _Rp) ? _Rp
2849c003db1fSHoward Hinnant                                           : __log2_imp<_Xp, _Rp - 1>::value;
28503e519524SHoward Hinnant};
28513e519524SHoward Hinnant
2852c003db1fSHoward Hinnanttemplate <unsigned long long _Xp>
2853c003db1fSHoward Hinnantstruct __log2_imp<_Xp, 0>
28543e519524SHoward Hinnant{
2855f9d540b0SHoward Hinnant    static const size_t value = 0;
28563e519524SHoward Hinnant};
28573e519524SHoward Hinnant
2858c003db1fSHoward Hinnanttemplate <size_t _Rp>
2859c003db1fSHoward Hinnantstruct __log2_imp<0, _Rp>
28603e519524SHoward Hinnant{
2861c003db1fSHoward Hinnant    static const size_t value = _Rp + 1;
28623e519524SHoward Hinnant};
28633e519524SHoward Hinnant
286489918caaSEric Fiseliertemplate <class _UIntType, _UIntType _Xp>
2865f9d540b0SHoward Hinnantstruct __log2
28663e519524SHoward Hinnant{
2867c003db1fSHoward Hinnant    static const size_t value = __log2_imp<_Xp,
286889918caaSEric Fiselier                                         sizeof(_UIntType) * __CHAR_BIT__ - 1>::value;
28693e519524SHoward Hinnant};
28703e519524SHoward Hinnant
2871f9d540b0SHoward Hinnanttemplate<class _Engine, class _UIntType>
2872f9d540b0SHoward Hinnantclass __independent_bits_engine
28733e519524SHoward Hinnant{
2874f9d540b0SHoward Hinnantpublic:
2875f9d540b0SHoward Hinnant    // types
2876f9d540b0SHoward Hinnant    typedef _UIntType result_type;
2877f9d540b0SHoward Hinnant
2878f9d540b0SHoward Hinnantprivate:
2879f9d540b0SHoward Hinnant    typedef typename _Engine::result_type _Engine_result_type;
2880f9d540b0SHoward Hinnant    typedef typename conditional
2881f9d540b0SHoward Hinnant        <
2882f9d540b0SHoward Hinnant            sizeof(_Engine_result_type) <= sizeof(result_type),
2883f9d540b0SHoward Hinnant                result_type,
2884f9d540b0SHoward Hinnant                _Engine_result_type
2885f9d540b0SHoward Hinnant        >::type _Working_result_type;
2886f9d540b0SHoward Hinnant
2887f9d540b0SHoward Hinnant    _Engine& __e_;
2888f9d540b0SHoward Hinnant    size_t __w_;
2889f9d540b0SHoward Hinnant    size_t __w0_;
2890f9d540b0SHoward Hinnant    size_t __n_;
2891f9d540b0SHoward Hinnant    size_t __n0_;
2892f9d540b0SHoward Hinnant    _Working_result_type __y0_;
2893f9d540b0SHoward Hinnant    _Working_result_type __y1_;
2894f9d540b0SHoward Hinnant    _Engine_result_type __mask0_;
2895f9d540b0SHoward Hinnant    _Engine_result_type __mask1_;
2896f9d540b0SHoward Hinnant
2897ddda456aSEric Fiselier#ifdef _LIBCPP_CXX03_LANG
2898c003db1fSHoward Hinnant    static const _Working_result_type _Rp = _Engine::_Max - _Engine::_Min
2899f9d540b0SHoward Hinnant                                          + _Working_result_type(1);
2900e386b7b3SHoward Hinnant#else
2901e386b7b3SHoward Hinnant    static _LIBCPP_CONSTEXPR const _Working_result_type _Rp = _Engine::max() - _Engine::min()
2902e386b7b3SHoward Hinnant                                                      + _Working_result_type(1);
2903e386b7b3SHoward Hinnant#endif
2904e386b7b3SHoward Hinnant    static _LIBCPP_CONSTEXPR const size_t __m = __log2<_Working_result_type, _Rp>::value;
2905e386b7b3SHoward Hinnant    static _LIBCPP_CONSTEXPR const size_t _WDt = numeric_limits<_Working_result_type>::digits;
2906e386b7b3SHoward Hinnant    static _LIBCPP_CONSTEXPR const size_t _EDt = numeric_limits<_Engine_result_type>::digits;
2907f9d540b0SHoward Hinnant
2908f9d540b0SHoward Hinnantpublic:
2909f9d540b0SHoward Hinnant    // constructors and seeding functions
2910f9d540b0SHoward Hinnant    __independent_bits_engine(_Engine& __e, size_t __w);
2911f9d540b0SHoward Hinnant
2912f9d540b0SHoward Hinnant    // generating functions
2913c003db1fSHoward Hinnant    result_type operator()() {return __eval(integral_constant<bool, _Rp != 0>());}
2914f9d540b0SHoward Hinnant
2915f9d540b0SHoward Hinnantprivate:
291608bba64aSMarshall Clow    result_type __eval(false_type);
291708bba64aSMarshall Clow    result_type __eval(true_type);
2918f9d540b0SHoward Hinnant};
2919f9d540b0SHoward Hinnant
2920f9d540b0SHoward Hinnanttemplate<class _Engine, class _UIntType>
2921f9d540b0SHoward Hinnant__independent_bits_engine<_Engine, _UIntType>
2922f9d540b0SHoward Hinnant    ::__independent_bits_engine(_Engine& __e, size_t __w)
2923f9d540b0SHoward Hinnant        : __e_(__e),
2924f9d540b0SHoward Hinnant          __w_(__w)
2925f9d540b0SHoward Hinnant{
2926f9d540b0SHoward Hinnant    __n_ = __w_ / __m + (__w_ % __m != 0);
2927f9d540b0SHoward Hinnant    __w0_ = __w_ / __n_;
2928c003db1fSHoward Hinnant    if (_Rp == 0)
2929c003db1fSHoward Hinnant        __y0_ = _Rp;
2930f9d540b0SHoward Hinnant    else if (__w0_ < _WDt)
2931c003db1fSHoward Hinnant        __y0_ = (_Rp >> __w0_) << __w0_;
2932f9d540b0SHoward Hinnant    else
2933f9d540b0SHoward Hinnant        __y0_ = 0;
2934c003db1fSHoward Hinnant    if (_Rp - __y0_ > __y0_ / __n_)
2935f9d540b0SHoward Hinnant    {
2936f9d540b0SHoward Hinnant        ++__n_;
2937f9d540b0SHoward Hinnant        __w0_ = __w_ / __n_;
2938f9d540b0SHoward Hinnant        if (__w0_ < _WDt)
2939c003db1fSHoward Hinnant            __y0_ = (_Rp >> __w0_) << __w0_;
2940f9d540b0SHoward Hinnant        else
2941f9d540b0SHoward Hinnant            __y0_ = 0;
2942f9d540b0SHoward Hinnant    }
2943f9d540b0SHoward Hinnant    __n0_ = __n_ - __w_ % __n_;
2944f9d540b0SHoward Hinnant    if (__w0_ < _WDt - 1)
2945c003db1fSHoward Hinnant        __y1_ = (_Rp >> (__w0_ + 1)) << (__w0_ + 1);
2946f9d540b0SHoward Hinnant    else
2947f9d540b0SHoward Hinnant        __y1_ = 0;
2948f9d540b0SHoward Hinnant    __mask0_ = __w0_ > 0 ? _Engine_result_type(~0) >> (_EDt - __w0_) :
2949f9d540b0SHoward Hinnant                          _Engine_result_type(0);
2950f9d540b0SHoward Hinnant    __mask1_ = __w0_ < _EDt - 1 ?
2951f9d540b0SHoward Hinnant                               _Engine_result_type(~0) >> (_EDt - (__w0_ + 1)) :
2952f9d540b0SHoward Hinnant                               _Engine_result_type(~0);
29533e519524SHoward Hinnant}
29543e519524SHoward Hinnant
2955f9d540b0SHoward Hinnanttemplate<class _Engine, class _UIntType>
2956f9d540b0SHoward Hinnantinline
2957f9d540b0SHoward Hinnant_UIntType
295808bba64aSMarshall Clow__independent_bits_engine<_Engine, _UIntType>::__eval(false_type)
29593e519524SHoward Hinnant{
2960f9d540b0SHoward Hinnant    return static_cast<result_type>(__e_() & __mask0_);
29613e519524SHoward Hinnant}
29623e519524SHoward Hinnant
2963f9d540b0SHoward Hinnanttemplate<class _Engine, class _UIntType>
2964f9d540b0SHoward Hinnant_UIntType
296508bba64aSMarshall Clow__independent_bits_engine<_Engine, _UIntType>::__eval(true_type)
29663e519524SHoward Hinnant{
29675beb2c3aSMarshall Clow    const size_t _WRt = numeric_limits<result_type>::digits;
2968c003db1fSHoward Hinnant    result_type _Sp = 0;
2969f9d540b0SHoward Hinnant    for (size_t __k = 0; __k < __n0_; ++__k)
2970f9d540b0SHoward Hinnant    {
2971f9d540b0SHoward Hinnant        _Engine_result_type __u;
29723e519524SHoward Hinnant        do
2973f9d540b0SHoward Hinnant        {
2974f9d540b0SHoward Hinnant            __u = __e_() - _Engine::min();
2975f9d540b0SHoward Hinnant        } while (__u >= __y0_);
29765beb2c3aSMarshall Clow        if (__w0_ < _WRt)
2977c003db1fSHoward Hinnant            _Sp <<= __w0_;
2978f9d540b0SHoward Hinnant        else
2979c003db1fSHoward Hinnant            _Sp = 0;
2980c003db1fSHoward Hinnant        _Sp += __u & __mask0_;
2981f9d540b0SHoward Hinnant    }
2982f9d540b0SHoward Hinnant    for (size_t __k = __n0_; __k < __n_; ++__k)
2983f9d540b0SHoward Hinnant    {
2984f9d540b0SHoward Hinnant        _Engine_result_type __u;
2985f9d540b0SHoward Hinnant        do
2986f9d540b0SHoward Hinnant        {
2987f9d540b0SHoward Hinnant            __u = __e_() - _Engine::min();
2988f9d540b0SHoward Hinnant        } while (__u >= __y1_);
29895beb2c3aSMarshall Clow        if (__w0_ < _WRt - 1)
2990c003db1fSHoward Hinnant            _Sp <<= __w0_ + 1;
2991f9d540b0SHoward Hinnant        else
2992c003db1fSHoward Hinnant            _Sp = 0;
2993c003db1fSHoward Hinnant        _Sp += __u & __mask1_;
2994f9d540b0SHoward Hinnant    }
2995c003db1fSHoward Hinnant    return _Sp;
29963e519524SHoward Hinnant}
29973e519524SHoward Hinnant
2998f9d540b0SHoward Hinnant// uniform_int_distribution
29993e519524SHoward Hinnant
3000f9d540b0SHoward Hinnanttemplate<class _IntType = int>
3001f9d540b0SHoward Hinnantclass uniform_int_distribution
30023e519524SHoward Hinnant{
3003f9d540b0SHoward Hinnantpublic:
3004f9d540b0SHoward Hinnant    // types
3005f9d540b0SHoward Hinnant    typedef _IntType result_type;
3006f9d540b0SHoward Hinnant
3007f9d540b0SHoward Hinnant    class param_type
3008f9d540b0SHoward Hinnant    {
3009f9d540b0SHoward Hinnant        result_type __a_;
3010f9d540b0SHoward Hinnant        result_type __b_;
3011f9d540b0SHoward Hinnant    public:
3012f9d540b0SHoward Hinnant        typedef uniform_int_distribution distribution_type;
3013f9d540b0SHoward Hinnant
3014f9d540b0SHoward Hinnant        explicit param_type(result_type __a = 0,
3015f9d540b0SHoward Hinnant                            result_type __b = numeric_limits<result_type>::max())
3016f9d540b0SHoward Hinnant            : __a_(__a), __b_(__b) {}
3017f9d540b0SHoward Hinnant
3018f9d540b0SHoward Hinnant        result_type a() const {return __a_;}
3019f9d540b0SHoward Hinnant        result_type b() const {return __b_;}
3020f9d540b0SHoward Hinnant
3021f9d540b0SHoward Hinnant        friend bool operator==(const param_type& __x, const param_type& __y)
3022f9d540b0SHoward Hinnant            {return __x.__a_ == __y.__a_ && __x.__b_ == __y.__b_;}
3023f9d540b0SHoward Hinnant        friend bool operator!=(const param_type& __x, const param_type& __y)
3024f9d540b0SHoward Hinnant            {return !(__x == __y);}
30253e519524SHoward Hinnant    };
30263e519524SHoward Hinnant
3027f9d540b0SHoward Hinnantprivate:
3028f9d540b0SHoward Hinnant    param_type __p_;
30293e519524SHoward Hinnant
3030f9d540b0SHoward Hinnantpublic:
3031f9d540b0SHoward Hinnant    // constructors and reset functions
3032f9d540b0SHoward Hinnant    explicit uniform_int_distribution(result_type __a = 0,
3033f9d540b0SHoward Hinnant                                      result_type __b = numeric_limits<result_type>::max())
3034f9d540b0SHoward Hinnant        : __p_(param_type(__a, __b)) {}
3035f9d540b0SHoward Hinnant    explicit uniform_int_distribution(const param_type& __p) : __p_(__p) {}
3036f9d540b0SHoward Hinnant    void reset() {}
3037f9d540b0SHoward Hinnant
3038f9d540b0SHoward Hinnant    // generating functions
3039f9d540b0SHoward Hinnant    template<class _URNG> result_type operator()(_URNG& __g)
3040f9d540b0SHoward Hinnant        {return (*this)(__g, __p_);}
3041f9d540b0SHoward Hinnant    template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
3042f9d540b0SHoward Hinnant
3043f9d540b0SHoward Hinnant    // property functions
3044f9d540b0SHoward Hinnant    result_type a() const {return __p_.a();}
3045f9d540b0SHoward Hinnant    result_type b() const {return __p_.b();}
3046f9d540b0SHoward Hinnant
3047f9d540b0SHoward Hinnant    param_type param() const {return __p_;}
3048f9d540b0SHoward Hinnant    void param(const param_type& __p) {__p_ = __p;}
3049f9d540b0SHoward Hinnant
3050f9d540b0SHoward Hinnant    result_type min() const {return a();}
3051f9d540b0SHoward Hinnant    result_type max() const {return b();}
3052f9d540b0SHoward Hinnant
3053f9d540b0SHoward Hinnant    friend bool operator==(const uniform_int_distribution& __x,
3054f9d540b0SHoward Hinnant                           const uniform_int_distribution& __y)
3055f9d540b0SHoward Hinnant        {return __x.__p_ == __y.__p_;}
3056f9d540b0SHoward Hinnant    friend bool operator!=(const uniform_int_distribution& __x,
3057f9d540b0SHoward Hinnant                           const uniform_int_distribution& __y)
3058f9d540b0SHoward Hinnant            {return !(__x == __y);}
30593e519524SHoward Hinnant};
30603e519524SHoward Hinnant
3061f9d540b0SHoward Hinnanttemplate<class _IntType>
3062f9d540b0SHoward Hinnanttemplate<class _URNG>
3063f9d540b0SHoward Hinnanttypename uniform_int_distribution<_IntType>::result_type
3064f9d540b0SHoward Hinnantuniform_int_distribution<_IntType>::operator()(_URNG& __g, const param_type& __p)
30652dd53352SMarshall Clow_LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK
30663e519524SHoward Hinnant{
3067f9d540b0SHoward Hinnant    typedef typename conditional<sizeof(result_type) <= sizeof(uint32_t),
3068f9d540b0SHoward Hinnant                                            uint32_t, uint64_t>::type _UIntType;
30692dd53352SMarshall Clow    const _UIntType _Rp = _UIntType(__p.b()) - _UIntType(__p.a()) + _UIntType(1);
3070c003db1fSHoward Hinnant    if (_Rp == 1)
3071f9d540b0SHoward Hinnant        return __p.a();
3072f9d540b0SHoward Hinnant    const size_t _Dt = numeric_limits<_UIntType>::digits;
3073f9d540b0SHoward Hinnant    typedef __independent_bits_engine<_URNG, _UIntType> _Eng;
3074c003db1fSHoward Hinnant    if (_Rp == 0)
3075f9d540b0SHoward Hinnant        return static_cast<result_type>(_Eng(__g, _Dt)());
3076f3b851f0SMarshall Clow    size_t __w = _Dt - __libcpp_clz(_Rp) - 1;
3077a6438ca1SMarshall Clow    if ((_Rp & (std::numeric_limits<_UIntType>::max() >> (_Dt - __w))) != 0)
3078f9d540b0SHoward Hinnant        ++__w;
3079f9d540b0SHoward Hinnant    _Eng __e(__g, __w);
3080f9d540b0SHoward Hinnant    _UIntType __u;
3081f9d540b0SHoward Hinnant    do
30823e519524SHoward Hinnant    {
3083f9d540b0SHoward Hinnant        __u = __e();
3084c003db1fSHoward Hinnant    } while (__u >= _Rp);
3085f9d540b0SHoward Hinnant    return static_cast<result_type>(__u + __p.a());
30863e519524SHoward Hinnant}
3087f9d540b0SHoward Hinnant
308866f1ec46SEric Fiselier#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_RANDOM_SHUFFLE) \
308966f1ec46SEric Fiselier  || defined(_LIBCPP_BUILDING_LIBRARY)
3090f0544c20SHoward Hinnantclass _LIBCPP_TYPE_VIS __rs_default;
3091f9d540b0SHoward Hinnant
3092f0544c20SHoward Hinnant_LIBCPP_FUNC_VIS __rs_default __rs_get();
3093f9d540b0SHoward Hinnant
3094f0544c20SHoward Hinnantclass _LIBCPP_TYPE_VIS __rs_default
30953e519524SHoward Hinnant{
3096f9d540b0SHoward Hinnant    static unsigned __c_;
3097f9d540b0SHoward Hinnant
3098f9d540b0SHoward Hinnant    __rs_default();
3099f9d540b0SHoward Hinnantpublic:
3100b6e5f854SMarshall Clow    typedef uint_fast32_t result_type;
3101f9d540b0SHoward Hinnant
3102f9d540b0SHoward Hinnant    static const result_type _Min = 0;
3103f9d540b0SHoward Hinnant    static const result_type _Max = 0xFFFFFFFF;
3104f9d540b0SHoward Hinnant
3105f9d540b0SHoward Hinnant    __rs_default(const __rs_default&);
3106f9d540b0SHoward Hinnant    ~__rs_default();
3107f9d540b0SHoward Hinnant
3108f9d540b0SHoward Hinnant    result_type operator()();
3109f9d540b0SHoward Hinnant
3110788c9979SHoward Hinnant    static _LIBCPP_CONSTEXPR result_type min() {return _Min;}
3111788c9979SHoward Hinnant    static _LIBCPP_CONSTEXPR result_type max() {return _Max;}
3112f9d540b0SHoward Hinnant
3113f0544c20SHoward Hinnant    friend _LIBCPP_FUNC_VIS __rs_default __rs_get();
3114f9d540b0SHoward Hinnant};
3115f9d540b0SHoward Hinnant
3116f0544c20SHoward Hinnant_LIBCPP_FUNC_VIS __rs_default __rs_get();
31173e519524SHoward Hinnant
31183e519524SHoward Hinnanttemplate <class _RandomAccessIterator>
3119ea5cd3b4SLouis Dionne_LIBCPP_DEPRECATED_IN_CXX14 void
31203e519524SHoward Hinnantrandom_shuffle(_RandomAccessIterator __first, _RandomAccessIterator __last)
31213e519524SHoward Hinnant{
31223e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
3123c003db1fSHoward Hinnant    typedef uniform_int_distribution<ptrdiff_t> _Dp;
3124c003db1fSHoward Hinnant    typedef typename _Dp::param_type _Pp;
31253e519524SHoward Hinnant    difference_type __d = __last - __first;
31263e519524SHoward Hinnant    if (__d > 1)
31273e519524SHoward Hinnant    {
3128c003db1fSHoward Hinnant        _Dp __uid;
3129f9d540b0SHoward Hinnant        __rs_default __g = __rs_get();
31305a8525e0SMarshall Clow        for (--__last, (void) --__d; __first < __last; ++__first, (void) --__d)
3131007b26beSHoward Hinnant        {
3132c003db1fSHoward Hinnant            difference_type __i = __uid(__g, _Pp(0, __d));
3133007b26beSHoward Hinnant            if (__i != difference_type(0))
3134007b26beSHoward Hinnant                swap(*__first, *(__first + __i));
3135007b26beSHoward Hinnant        }
31363e519524SHoward Hinnant    }
31373e519524SHoward Hinnant}
31383e519524SHoward Hinnant
31393e519524SHoward Hinnanttemplate <class _RandomAccessIterator, class _RandomNumberGenerator>
3140ea5cd3b4SLouis Dionne_LIBCPP_DEPRECATED_IN_CXX14 void
31413e519524SHoward Hinnantrandom_shuffle(_RandomAccessIterator __first, _RandomAccessIterator __last,
3142ddda456aSEric Fiselier#ifndef _LIBCPP_CXX03_LANG
31433e519524SHoward Hinnant               _RandomNumberGenerator&& __rand)
31443e519524SHoward Hinnant#else
31453e519524SHoward Hinnant               _RandomNumberGenerator& __rand)
31463e519524SHoward Hinnant#endif
31473e519524SHoward Hinnant{
31483e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
31493e519524SHoward Hinnant    difference_type __d = __last - __first;
31503e519524SHoward Hinnant    if (__d > 1)
31513e519524SHoward Hinnant    {
31525a8525e0SMarshall Clow        for (--__last; __first < __last; ++__first, (void) --__d)
3153007b26beSHoward Hinnant        {
3154007b26beSHoward Hinnant            difference_type __i = __rand(__d);
3155e9cc5451SMarshall Clow            if (__i != difference_type(0))
3156007b26beSHoward Hinnant              swap(*__first, *(__first + __i));
3157007b26beSHoward Hinnant        }
31583e519524SHoward Hinnant    }
31593e519524SHoward Hinnant}
31600f37a410SMarshall Clow#endif
31613e519524SHoward Hinnant
3162e7154709SEric Fiseliertemplate <class _PopulationIterator, class _SampleIterator, class _Distance,
3163e7154709SEric Fiselier          class _UniformRandomNumberGenerator>
3164e7154709SEric Fiselier_LIBCPP_INLINE_VISIBILITY
3165e7154709SEric Fiselier_SampleIterator __sample(_PopulationIterator __first,
316642bfedd9SAlexander Richardson                         _PopulationIterator __last, _SampleIterator __output_iter,
3167e7154709SEric Fiselier                         _Distance __n,
3168e7154709SEric Fiselier                         _UniformRandomNumberGenerator & __g,
3169e7154709SEric Fiselier                         input_iterator_tag) {
3170e7154709SEric Fiselier
3171e7154709SEric Fiselier  _Distance __k = 0;
3172e7154709SEric Fiselier  for (; __first != __last && __k < __n; ++__first, (void) ++__k)
317342bfedd9SAlexander Richardson    __output_iter[__k] = *__first;
3174e7154709SEric Fiselier  _Distance __sz = __k;
3175e7154709SEric Fiselier  for (; __first != __last; ++__first, (void) ++__k) {
3176e7154709SEric Fiselier    _Distance __r = _VSTD::uniform_int_distribution<_Distance>(0, __k)(__g);
3177e7154709SEric Fiselier    if (__r < __sz)
317842bfedd9SAlexander Richardson      __output_iter[__r] = *__first;
3179e7154709SEric Fiselier  }
318042bfedd9SAlexander Richardson  return __output_iter + _VSTD::min(__n, __k);
3181e7154709SEric Fiselier}
3182e7154709SEric Fiselier
3183e7154709SEric Fiseliertemplate <class _PopulationIterator, class _SampleIterator, class _Distance,
3184e7154709SEric Fiselier          class _UniformRandomNumberGenerator>
3185e7154709SEric Fiselier_LIBCPP_INLINE_VISIBILITY
3186e7154709SEric Fiselier_SampleIterator __sample(_PopulationIterator __first,
318742bfedd9SAlexander Richardson                         _PopulationIterator __last, _SampleIterator __output_iter,
3188e7154709SEric Fiselier                         _Distance __n,
3189e7154709SEric Fiselier                         _UniformRandomNumberGenerator& __g,
3190e7154709SEric Fiselier                         forward_iterator_tag) {
3191e7154709SEric Fiselier  _Distance __unsampled_sz = _VSTD::distance(__first, __last);
3192e7154709SEric Fiselier  for (__n = _VSTD::min(__n, __unsampled_sz); __n != 0; ++__first) {
3193e7154709SEric Fiselier    _Distance __r =
3194e7154709SEric Fiselier        _VSTD::uniform_int_distribution<_Distance>(0, --__unsampled_sz)(__g);
3195e7154709SEric Fiselier    if (__r < __n) {
319642bfedd9SAlexander Richardson      *__output_iter++ = *__first;
3197e7154709SEric Fiselier      --__n;
3198e7154709SEric Fiselier    }
3199e7154709SEric Fiselier  }
320042bfedd9SAlexander Richardson  return __output_iter;
3201e7154709SEric Fiselier}
3202e7154709SEric Fiselier
3203e7154709SEric Fiseliertemplate <class _PopulationIterator, class _SampleIterator, class _Distance,
3204e7154709SEric Fiselier          class _UniformRandomNumberGenerator>
3205e7154709SEric Fiselier_LIBCPP_INLINE_VISIBILITY
3206e7154709SEric Fiselier_SampleIterator __sample(_PopulationIterator __first,
320742bfedd9SAlexander Richardson                         _PopulationIterator __last, _SampleIterator __output_iter,
3208e7154709SEric Fiselier                         _Distance __n, _UniformRandomNumberGenerator& __g) {
3209e7154709SEric Fiselier  typedef typename iterator_traits<_PopulationIterator>::iterator_category
3210e7154709SEric Fiselier        _PopCategory;
3211e7154709SEric Fiselier  typedef typename iterator_traits<_PopulationIterator>::difference_type
3212e7154709SEric Fiselier        _Difference;
3213f82dba01SEric Fiselier  static_assert(__is_cpp17_forward_iterator<_PopulationIterator>::value ||
3214f82dba01SEric Fiselier                __is_cpp17_random_access_iterator<_SampleIterator>::value,
3215e7154709SEric Fiselier                "SampleIterator must meet the requirements of RandomAccessIterator");
3216e7154709SEric Fiselier  typedef typename common_type<_Distance, _Difference>::type _CommonType;
3217e7154709SEric Fiselier  _LIBCPP_ASSERT(__n >= 0, "N must be a positive number.");
3218e7154709SEric Fiselier  return _VSTD::__sample(
321942bfedd9SAlexander Richardson      __first, __last, __output_iter, _CommonType(__n),
3220e7154709SEric Fiselier      __g, _PopCategory());
3221e7154709SEric Fiselier}
3222e7154709SEric Fiselier
3223e7154709SEric Fiselier#if _LIBCPP_STD_VER > 14
3224e7154709SEric Fiseliertemplate <class _PopulationIterator, class _SampleIterator, class _Distance,
3225e7154709SEric Fiselier          class _UniformRandomNumberGenerator>
3226e7154709SEric Fiselierinline _LIBCPP_INLINE_VISIBILITY
3227e7154709SEric Fiselier_SampleIterator sample(_PopulationIterator __first,
322842bfedd9SAlexander Richardson                       _PopulationIterator __last, _SampleIterator __output_iter,
3229e7154709SEric Fiselier                       _Distance __n, _UniformRandomNumberGenerator&& __g) {
323042bfedd9SAlexander Richardson    return _VSTD::__sample(__first, __last, __output_iter, __n, __g);
3231e7154709SEric Fiselier}
3232e7154709SEric Fiselier#endif // _LIBCPP_STD_VER > 14
3233e7154709SEric Fiselier
3234f9d540b0SHoward Hinnanttemplate<class _RandomAccessIterator, class _UniformRandomNumberGenerator>
3235f9d540b0SHoward Hinnant    void shuffle(_RandomAccessIterator __first, _RandomAccessIterator __last,
3236fb340102SHoward Hinnant                 _UniformRandomNumberGenerator&& __g)
3237f9d540b0SHoward Hinnant{
3238f9d540b0SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
3239c003db1fSHoward Hinnant    typedef uniform_int_distribution<ptrdiff_t> _Dp;
3240c003db1fSHoward Hinnant    typedef typename _Dp::param_type _Pp;
3241f9d540b0SHoward Hinnant    difference_type __d = __last - __first;
3242f9d540b0SHoward Hinnant    if (__d > 1)
3243f9d540b0SHoward Hinnant    {
3244c003db1fSHoward Hinnant        _Dp __uid;
32457fa68653SMarshall Clow        for (--__last, (void) --__d; __first < __last; ++__first, (void) --__d)
3246007b26beSHoward Hinnant        {
3247c003db1fSHoward Hinnant            difference_type __i = __uid(__g, _Pp(0, __d));
3248007b26beSHoward Hinnant            if (__i != difference_type(0))
3249007b26beSHoward Hinnant                swap(*__first, *(__first + __i));
3250007b26beSHoward Hinnant        }
3251f9d540b0SHoward Hinnant    }
3252f9d540b0SHoward Hinnant}
3253f9d540b0SHoward Hinnant
32543e519524SHoward Hinnanttemplate <class _InputIterator, class _Predicate>
32551362d7efSNico Weber_LIBCPP_NODISCARD_EXT _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
32563e519524SHoward Hinnantis_partitioned(_InputIterator __first, _InputIterator __last, _Predicate __pred)
32573e519524SHoward Hinnant{
32583e519524SHoward Hinnant    for (; __first != __last; ++__first)
32593e519524SHoward Hinnant        if (!__pred(*__first))
32603e519524SHoward Hinnant            break;
3261b9595b79SMarshall Clow    if ( __first == __last )
3262b9595b79SMarshall Clow        return true;
3263b9595b79SMarshall Clow    ++__first;
32643e519524SHoward Hinnant    for (; __first != __last; ++__first)
32653e519524SHoward Hinnant        if (__pred(*__first))
32663e519524SHoward Hinnant            return false;
32673e519524SHoward Hinnant    return true;
32683e519524SHoward Hinnant}
32693e519524SHoward Hinnant
32703e519524SHoward Hinnant// partition
32713e519524SHoward Hinnant
32723e519524SHoward Hinnanttemplate <class _Predicate, class _ForwardIterator>
32733e519524SHoward Hinnant_ForwardIterator
32743e519524SHoward Hinnant__partition(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred, forward_iterator_tag)
32753e519524SHoward Hinnant{
32763e519524SHoward Hinnant    while (true)
32773e519524SHoward Hinnant    {
32783e519524SHoward Hinnant        if (__first == __last)
32793e519524SHoward Hinnant            return __first;
32803e519524SHoward Hinnant        if (!__pred(*__first))
32813e519524SHoward Hinnant            break;
32823e519524SHoward Hinnant        ++__first;
32833e519524SHoward Hinnant    }
32843e519524SHoward Hinnant    for (_ForwardIterator __p = __first; ++__p != __last;)
32853e519524SHoward Hinnant    {
32863e519524SHoward Hinnant        if (__pred(*__p))
32873e519524SHoward Hinnant        {
32883e519524SHoward Hinnant            swap(*__first, *__p);
32893e519524SHoward Hinnant            ++__first;
32903e519524SHoward Hinnant        }
32913e519524SHoward Hinnant    }
32923e519524SHoward Hinnant    return __first;
32933e519524SHoward Hinnant}
32943e519524SHoward Hinnant
32953e519524SHoward Hinnanttemplate <class _Predicate, class _BidirectionalIterator>
32963e519524SHoward Hinnant_BidirectionalIterator
32973e519524SHoward Hinnant__partition(_BidirectionalIterator __first, _BidirectionalIterator __last, _Predicate __pred,
32983e519524SHoward Hinnant            bidirectional_iterator_tag)
32993e519524SHoward Hinnant{
33003e519524SHoward Hinnant    while (true)
33013e519524SHoward Hinnant    {
33023e519524SHoward Hinnant        while (true)
33033e519524SHoward Hinnant        {
33043e519524SHoward Hinnant            if (__first == __last)
33053e519524SHoward Hinnant                return __first;
33063e519524SHoward Hinnant            if (!__pred(*__first))
33073e519524SHoward Hinnant                break;
33083e519524SHoward Hinnant            ++__first;
33093e519524SHoward Hinnant        }
33103e519524SHoward Hinnant        do
33113e519524SHoward Hinnant        {
33123e519524SHoward Hinnant            if (__first == --__last)
33133e519524SHoward Hinnant                return __first;
33143e519524SHoward Hinnant        } while (!__pred(*__last));
33153e519524SHoward Hinnant        swap(*__first, *__last);
33163e519524SHoward Hinnant        ++__first;
33173e519524SHoward Hinnant    }
33183e519524SHoward Hinnant}
33193e519524SHoward Hinnant
33203e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Predicate>
33213e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
33223e519524SHoward Hinnant_ForwardIterator
33233e519524SHoward Hinnantpartition(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred)
33243e519524SHoward Hinnant{
3325ce48a113SHoward Hinnant    return _VSTD::__partition<typename add_lvalue_reference<_Predicate>::type>
33263e519524SHoward Hinnant                            (__first, __last, __pred, typename iterator_traits<_ForwardIterator>::iterator_category());
33273e519524SHoward Hinnant}
33283e519524SHoward Hinnant
33293e519524SHoward Hinnant// partition_copy
33303e519524SHoward Hinnant
33313e519524SHoward Hinnanttemplate <class _InputIterator, class _OutputIterator1,
33323e519524SHoward Hinnant          class _OutputIterator2, class _Predicate>
33331b9a4ffdSMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 pair<_OutputIterator1, _OutputIterator2>
33343e519524SHoward Hinnantpartition_copy(_InputIterator __first, _InputIterator __last,
33353e519524SHoward Hinnant               _OutputIterator1 __out_true, _OutputIterator2 __out_false,
33363e519524SHoward Hinnant               _Predicate __pred)
33373e519524SHoward Hinnant{
33383e519524SHoward Hinnant    for (; __first != __last; ++__first)
33393e519524SHoward Hinnant    {
33403e519524SHoward Hinnant        if (__pred(*__first))
33413e519524SHoward Hinnant        {
33423e519524SHoward Hinnant            *__out_true = *__first;
33433e519524SHoward Hinnant            ++__out_true;
33443e519524SHoward Hinnant        }
33453e519524SHoward Hinnant        else
33463e519524SHoward Hinnant        {
33473e519524SHoward Hinnant            *__out_false = *__first;
33483e519524SHoward Hinnant            ++__out_false;
33493e519524SHoward Hinnant        }
33503e519524SHoward Hinnant    }
33513e519524SHoward Hinnant    return pair<_OutputIterator1, _OutputIterator2>(__out_true, __out_false);
33523e519524SHoward Hinnant}
33533e519524SHoward Hinnant
33543e519524SHoward Hinnant// partition_point
33553e519524SHoward Hinnant
33563e519524SHoward Hinnanttemplate<class _ForwardIterator, class _Predicate>
3357674f9128SMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
33583e519524SHoward Hinnantpartition_point(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred)
33593e519524SHoward Hinnant{
33603e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator>::difference_type difference_type;
3361ce48a113SHoward Hinnant    difference_type __len = _VSTD::distance(__first, __last);
33623e519524SHoward Hinnant    while (__len != 0)
33633e519524SHoward Hinnant    {
336404695a75SLouis Dionne        difference_type __l2 = _VSTD::__half_positive(__len);
33653e519524SHoward Hinnant        _ForwardIterator __m = __first;
3366ce48a113SHoward Hinnant        _VSTD::advance(__m, __l2);
33673e519524SHoward Hinnant        if (__pred(*__m))
33683e519524SHoward Hinnant        {
33693e519524SHoward Hinnant            __first = ++__m;
33703e519524SHoward Hinnant            __len -= __l2 + 1;
33713e519524SHoward Hinnant        }
33723e519524SHoward Hinnant        else
33733e519524SHoward Hinnant            __len = __l2;
33743e519524SHoward Hinnant    }
33753e519524SHoward Hinnant    return __first;
33763e519524SHoward Hinnant}
33773e519524SHoward Hinnant
33783e519524SHoward Hinnant// stable_partition
33793e519524SHoward Hinnant
33803e519524SHoward Hinnanttemplate <class _Predicate, class _ForwardIterator, class _Distance, class _Pair>
33813e519524SHoward Hinnant_ForwardIterator
33823e519524SHoward Hinnant__stable_partition(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred,
33833e519524SHoward Hinnant                   _Distance __len, _Pair __p, forward_iterator_tag __fit)
33843e519524SHoward Hinnant{
33853e519524SHoward Hinnant    // *__first is known to be false
33863e519524SHoward Hinnant    // __len >= 1
33873e519524SHoward Hinnant    if (__len == 1)
33883e519524SHoward Hinnant        return __first;
33893e519524SHoward Hinnant    if (__len == 2)
33903e519524SHoward Hinnant    {
33913e519524SHoward Hinnant        _ForwardIterator __m = __first;
33923e519524SHoward Hinnant        if (__pred(*++__m))
33933e519524SHoward Hinnant        {
33943e519524SHoward Hinnant            swap(*__first, *__m);
33953e519524SHoward Hinnant            return __m;
33963e519524SHoward Hinnant        }
33973e519524SHoward Hinnant        return __first;
33983e519524SHoward Hinnant    }
33993e519524SHoward Hinnant    if (__len <= __p.second)
34003e519524SHoward Hinnant    {   // The buffer is big enough to use
34013e519524SHoward Hinnant        typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
34023e519524SHoward Hinnant        __destruct_n __d(0);
34033e519524SHoward Hinnant        unique_ptr<value_type, __destruct_n&> __h(__p.first, __d);
34043e519524SHoward Hinnant        // Move the falses into the temporary buffer, and the trues to the front of the line
34053e519524SHoward Hinnant        // Update __first to always point to the end of the trues
34063e519524SHoward Hinnant        value_type* __t = __p.first;
3407ce48a113SHoward Hinnant        ::new(__t) value_type(_VSTD::move(*__first));
34083e519524SHoward Hinnant        __d.__incr((value_type*)0);
34093e519524SHoward Hinnant        ++__t;
34103e519524SHoward Hinnant        _ForwardIterator __i = __first;
34113e519524SHoward Hinnant        while (++__i != __last)
34123e519524SHoward Hinnant        {
34133e519524SHoward Hinnant            if (__pred(*__i))
34143e519524SHoward Hinnant            {
3415ce48a113SHoward Hinnant                *__first = _VSTD::move(*__i);
34163e519524SHoward Hinnant                ++__first;
34173e519524SHoward Hinnant            }
34183e519524SHoward Hinnant            else
34193e519524SHoward Hinnant            {
3420ce48a113SHoward Hinnant                ::new(__t) value_type(_VSTD::move(*__i));
34213e519524SHoward Hinnant                __d.__incr((value_type*)0);
34223e519524SHoward Hinnant                ++__t;
34233e519524SHoward Hinnant            }
34243e519524SHoward Hinnant        }
34253e519524SHoward Hinnant        // All trues now at start of range, all falses in buffer
34263e519524SHoward Hinnant        // Move falses back into range, but don't mess up __first which points to first false
34273e519524SHoward Hinnant        __i = __first;
34287fa68653SMarshall Clow        for (value_type* __t2 = __p.first; __t2 < __t; ++__t2, (void) ++__i)
3429ce48a113SHoward Hinnant            *__i = _VSTD::move(*__t2);
34303e519524SHoward Hinnant        // __h destructs moved-from values out of the temp buffer, but doesn't deallocate buffer
34313e519524SHoward Hinnant        return __first;
34323e519524SHoward Hinnant    }
34333e519524SHoward Hinnant    // Else not enough buffer, do in place
34343e519524SHoward Hinnant    // __len >= 3
34353e519524SHoward Hinnant    _ForwardIterator __m = __first;
34363e519524SHoward Hinnant    _Distance __len2 = __len / 2;  // __len2 >= 2
3437ce48a113SHoward Hinnant    _VSTD::advance(__m, __len2);
34383e519524SHoward Hinnant    // recurse on [__first, __m), *__first know to be false
34393e519524SHoward Hinnant    // F?????????????????
34403e519524SHoward Hinnant    // f       m         l
34413e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Predicate>::type _PredRef;
34423e519524SHoward Hinnant    _ForwardIterator __first_false = __stable_partition<_PredRef>(__first, __m, __pred, __len2, __p, __fit);
34433e519524SHoward Hinnant    // TTTFFFFF??????????
34443e519524SHoward Hinnant    // f  ff   m         l
34453e519524SHoward Hinnant    // recurse on [__m, __last], except increase __m until *(__m) is false, *__last know to be true
34463e519524SHoward Hinnant    _ForwardIterator __m1 = __m;
34473e519524SHoward Hinnant    _ForwardIterator __second_false = __last;
34483e519524SHoward Hinnant    _Distance __len_half = __len - __len2;
34493e519524SHoward Hinnant    while (__pred(*__m1))
34503e519524SHoward Hinnant    {
34513e519524SHoward Hinnant        if (++__m1 == __last)
34523e519524SHoward Hinnant            goto __second_half_done;
34533e519524SHoward Hinnant        --__len_half;
34543e519524SHoward Hinnant    }
34553e519524SHoward Hinnant    // TTTFFFFFTTTF??????
34563e519524SHoward Hinnant    // f  ff   m  m1     l
34573e519524SHoward Hinnant    __second_false = __stable_partition<_PredRef>(__m1, __last, __pred, __len_half, __p, __fit);
34583e519524SHoward Hinnant__second_half_done:
34593e519524SHoward Hinnant    // TTTFFFFFTTTTTFFFFF
34603e519524SHoward Hinnant    // f  ff   m    sf   l
3461ce48a113SHoward Hinnant    return _VSTD::rotate(__first_false, __m, __second_false);
34623e519524SHoward Hinnant    // TTTTTTTTFFFFFFFFFF
34633e519524SHoward Hinnant    //         |
34643e519524SHoward Hinnant}
34653e519524SHoward Hinnant
34663e519524SHoward Hinnantstruct __return_temporary_buffer
34673e519524SHoward Hinnant{
34683e519524SHoward Hinnant    template <class _Tp>
3469ce48a113SHoward Hinnant    _LIBCPP_INLINE_VISIBILITY void operator()(_Tp* __p) const {_VSTD::return_temporary_buffer(__p);}
34703e519524SHoward Hinnant};
34713e519524SHoward Hinnant
34723e519524SHoward Hinnanttemplate <class _Predicate, class _ForwardIterator>
34733e519524SHoward Hinnant_ForwardIterator
34743e519524SHoward Hinnant__stable_partition(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred,
34753e519524SHoward Hinnant                   forward_iterator_tag)
34763e519524SHoward Hinnant{
34773e519524SHoward Hinnant    const unsigned __alloc_limit = 3;  // might want to make this a function of trivial assignment
34783e519524SHoward Hinnant    // Either prove all true and return __first or point to first false
34793e519524SHoward Hinnant    while (true)
34803e519524SHoward Hinnant    {
34813e519524SHoward Hinnant        if (__first == __last)
34823e519524SHoward Hinnant            return __first;
34833e519524SHoward Hinnant        if (!__pred(*__first))
34843e519524SHoward Hinnant            break;
34853e519524SHoward Hinnant        ++__first;
34863e519524SHoward Hinnant    }
34873e519524SHoward Hinnant    // We now have a reduced range [__first, __last)
34883e519524SHoward Hinnant    // *__first is known to be false
34893e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator>::difference_type difference_type;
34903e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
3491ce48a113SHoward Hinnant    difference_type __len = _VSTD::distance(__first, __last);
34923e519524SHoward Hinnant    pair<value_type*, ptrdiff_t> __p(0, 0);
34933e519524SHoward Hinnant    unique_ptr<value_type, __return_temporary_buffer> __h;
34943e519524SHoward Hinnant    if (__len >= __alloc_limit)
34953e519524SHoward Hinnant    {
3496ce48a113SHoward Hinnant        __p = _VSTD::get_temporary_buffer<value_type>(__len);
34973e519524SHoward Hinnant        __h.reset(__p.first);
34983e519524SHoward Hinnant    }
34993e519524SHoward Hinnant    return __stable_partition<typename add_lvalue_reference<_Predicate>::type>
35003e519524SHoward Hinnant                             (__first, __last, __pred, __len, __p, forward_iterator_tag());
35013e519524SHoward Hinnant}
35023e519524SHoward Hinnant
35033e519524SHoward Hinnanttemplate <class _Predicate, class _BidirectionalIterator, class _Distance, class _Pair>
35043e519524SHoward Hinnant_BidirectionalIterator
35053e519524SHoward Hinnant__stable_partition(_BidirectionalIterator __first, _BidirectionalIterator __last, _Predicate __pred,
35063e519524SHoward Hinnant                   _Distance __len, _Pair __p, bidirectional_iterator_tag __bit)
35073e519524SHoward Hinnant{
35083e519524SHoward Hinnant    // *__first is known to be false
35093e519524SHoward Hinnant    // *__last is known to be true
35103e519524SHoward Hinnant    // __len >= 2
35113e519524SHoward Hinnant    if (__len == 2)
35123e519524SHoward Hinnant    {
35133e519524SHoward Hinnant        swap(*__first, *__last);
35143e519524SHoward Hinnant        return __last;
35153e519524SHoward Hinnant    }
35163e519524SHoward Hinnant    if (__len == 3)
35173e519524SHoward Hinnant    {
35183e519524SHoward Hinnant        _BidirectionalIterator __m = __first;
35193e519524SHoward Hinnant        if (__pred(*++__m))
35203e519524SHoward Hinnant        {
35213e519524SHoward Hinnant            swap(*__first, *__m);
35223e519524SHoward Hinnant            swap(*__m, *__last);
35233e519524SHoward Hinnant            return __last;
35243e519524SHoward Hinnant        }
35253e519524SHoward Hinnant        swap(*__m, *__last);
35263e519524SHoward Hinnant        swap(*__first, *__m);
35273e519524SHoward Hinnant        return __m;
35283e519524SHoward Hinnant    }
35293e519524SHoward Hinnant    if (__len <= __p.second)
35303e519524SHoward Hinnant    {   // The buffer is big enough to use
35313e519524SHoward Hinnant        typedef typename iterator_traits<_BidirectionalIterator>::value_type value_type;
35323e519524SHoward Hinnant        __destruct_n __d(0);
35333e519524SHoward Hinnant        unique_ptr<value_type, __destruct_n&> __h(__p.first, __d);
35343e519524SHoward Hinnant        // Move the falses into the temporary buffer, and the trues to the front of the line
35353e519524SHoward Hinnant        // Update __first to always point to the end of the trues
35363e519524SHoward Hinnant        value_type* __t = __p.first;
3537ce48a113SHoward Hinnant        ::new(__t) value_type(_VSTD::move(*__first));
35383e519524SHoward Hinnant        __d.__incr((value_type*)0);
35393e519524SHoward Hinnant        ++__t;
35403e519524SHoward Hinnant        _BidirectionalIterator __i = __first;
35413e519524SHoward Hinnant        while (++__i != __last)
35423e519524SHoward Hinnant        {
35433e519524SHoward Hinnant            if (__pred(*__i))
35443e519524SHoward Hinnant            {
3545ce48a113SHoward Hinnant                *__first = _VSTD::move(*__i);
35463e519524SHoward Hinnant                ++__first;
35473e519524SHoward Hinnant            }
35483e519524SHoward Hinnant            else
35493e519524SHoward Hinnant            {
3550ce48a113SHoward Hinnant                ::new(__t) value_type(_VSTD::move(*__i));
35513e519524SHoward Hinnant                __d.__incr((value_type*)0);
35523e519524SHoward Hinnant                ++__t;
35533e519524SHoward Hinnant            }
35543e519524SHoward Hinnant        }
35553e519524SHoward Hinnant        // move *__last, known to be true
3556ce48a113SHoward Hinnant        *__first = _VSTD::move(*__i);
35573e519524SHoward Hinnant        __i = ++__first;
35583e519524SHoward Hinnant        // All trues now at start of range, all falses in buffer
35593e519524SHoward Hinnant        // Move falses back into range, but don't mess up __first which points to first false
35607fa68653SMarshall Clow        for (value_type* __t2 = __p.first; __t2 < __t; ++__t2, (void) ++__i)
3561ce48a113SHoward Hinnant            *__i = _VSTD::move(*__t2);
35623e519524SHoward Hinnant        // __h destructs moved-from values out of the temp buffer, but doesn't deallocate buffer
35633e519524SHoward Hinnant        return __first;
35643e519524SHoward Hinnant    }
35653e519524SHoward Hinnant    // Else not enough buffer, do in place
35663e519524SHoward Hinnant    // __len >= 4
35673e519524SHoward Hinnant    _BidirectionalIterator __m = __first;
35683e519524SHoward Hinnant    _Distance __len2 = __len / 2;  // __len2 >= 2
3569ce48a113SHoward Hinnant    _VSTD::advance(__m, __len2);
35703e519524SHoward Hinnant    // recurse on [__first, __m-1], except reduce __m-1 until *(__m-1) is true, *__first know to be false
35713e519524SHoward Hinnant    // F????????????????T
35723e519524SHoward Hinnant    // f       m        l
35733e519524SHoward Hinnant    _BidirectionalIterator __m1 = __m;
35743e519524SHoward Hinnant    _BidirectionalIterator __first_false = __first;
35753e519524SHoward Hinnant    _Distance __len_half = __len2;
35763e519524SHoward Hinnant    while (!__pred(*--__m1))
35773e519524SHoward Hinnant    {
35783e519524SHoward Hinnant        if (__m1 == __first)
35793e519524SHoward Hinnant            goto __first_half_done;
35803e519524SHoward Hinnant        --__len_half;
35813e519524SHoward Hinnant    }
35823e519524SHoward Hinnant    // F???TFFF?????????T
35833e519524SHoward Hinnant    // f   m1  m        l
35843e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Predicate>::type _PredRef;
35853e519524SHoward Hinnant    __first_false = __stable_partition<_PredRef>(__first, __m1, __pred, __len_half, __p, __bit);
35863e519524SHoward Hinnant__first_half_done:
35873e519524SHoward Hinnant    // TTTFFFFF?????????T
35883e519524SHoward Hinnant    // f  ff   m        l
35893e519524SHoward Hinnant    // recurse on [__m, __last], except increase __m until *(__m) is false, *__last know to be true
35903e519524SHoward Hinnant    __m1 = __m;
35913e519524SHoward Hinnant    _BidirectionalIterator __second_false = __last;
35923e519524SHoward Hinnant    ++__second_false;
35933e519524SHoward Hinnant    __len_half = __len - __len2;
35943e519524SHoward Hinnant    while (__pred(*__m1))
35953e519524SHoward Hinnant    {
35963e519524SHoward Hinnant        if (++__m1 == __last)
35973e519524SHoward Hinnant            goto __second_half_done;
35983e519524SHoward Hinnant        --__len_half;
35993e519524SHoward Hinnant    }
36003e519524SHoward Hinnant    // TTTFFFFFTTTF?????T
36013e519524SHoward Hinnant    // f  ff   m  m1    l
36023e519524SHoward Hinnant    __second_false = __stable_partition<_PredRef>(__m1, __last, __pred, __len_half, __p, __bit);
36033e519524SHoward Hinnant__second_half_done:
36043e519524SHoward Hinnant    // TTTFFFFFTTTTTFFFFF
36053e519524SHoward Hinnant    // f  ff   m    sf  l
3606ce48a113SHoward Hinnant    return _VSTD::rotate(__first_false, __m, __second_false);
36073e519524SHoward Hinnant    // TTTTTTTTFFFFFFFFFF
36083e519524SHoward Hinnant    //         |
36093e519524SHoward Hinnant}
36103e519524SHoward Hinnant
36113e519524SHoward Hinnanttemplate <class _Predicate, class _BidirectionalIterator>
36123e519524SHoward Hinnant_BidirectionalIterator
36133e519524SHoward Hinnant__stable_partition(_BidirectionalIterator __first, _BidirectionalIterator __last, _Predicate __pred,
36143e519524SHoward Hinnant                   bidirectional_iterator_tag)
36153e519524SHoward Hinnant{
36163e519524SHoward Hinnant    typedef typename iterator_traits<_BidirectionalIterator>::difference_type difference_type;
36173e519524SHoward Hinnant    typedef typename iterator_traits<_BidirectionalIterator>::value_type value_type;
36183e519524SHoward Hinnant    const difference_type __alloc_limit = 4;  // might want to make this a function of trivial assignment
36193e519524SHoward Hinnant    // Either prove all true and return __first or point to first false
36203e519524SHoward Hinnant    while (true)
36213e519524SHoward Hinnant    {
36223e519524SHoward Hinnant        if (__first == __last)
36233e519524SHoward Hinnant            return __first;
36243e519524SHoward Hinnant        if (!__pred(*__first))
36253e519524SHoward Hinnant            break;
36263e519524SHoward Hinnant        ++__first;
36273e519524SHoward Hinnant    }
36283e519524SHoward Hinnant    // __first points to first false, everything prior to __first is already set.
36293e519524SHoward Hinnant    // Either prove [__first, __last) is all false and return __first, or point __last to last true
36303e519524SHoward Hinnant    do
36313e519524SHoward Hinnant    {
36323e519524SHoward Hinnant        if (__first == --__last)
36333e519524SHoward Hinnant            return __first;
36343e519524SHoward Hinnant    } while (!__pred(*__last));
36353e519524SHoward Hinnant    // We now have a reduced range [__first, __last]
36363e519524SHoward Hinnant    // *__first is known to be false
36373e519524SHoward Hinnant    // *__last is known to be true
36383e519524SHoward Hinnant    // __len >= 2
3639ce48a113SHoward Hinnant    difference_type __len = _VSTD::distance(__first, __last) + 1;
36403e519524SHoward Hinnant    pair<value_type*, ptrdiff_t> __p(0, 0);
36413e519524SHoward Hinnant    unique_ptr<value_type, __return_temporary_buffer> __h;
36423e519524SHoward Hinnant    if (__len >= __alloc_limit)
36433e519524SHoward Hinnant    {
3644ce48a113SHoward Hinnant        __p = _VSTD::get_temporary_buffer<value_type>(__len);
36453e519524SHoward Hinnant        __h.reset(__p.first);
36463e519524SHoward Hinnant    }
36473e519524SHoward Hinnant    return __stable_partition<typename add_lvalue_reference<_Predicate>::type>
36483e519524SHoward Hinnant                             (__first, __last, __pred, __len, __p, bidirectional_iterator_tag());
36493e519524SHoward Hinnant}
36503e519524SHoward Hinnant
36513e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Predicate>
36523e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
36533e519524SHoward Hinnant_ForwardIterator
36543e519524SHoward Hinnantstable_partition(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred)
36553e519524SHoward Hinnant{
36563e519524SHoward Hinnant    return __stable_partition<typename add_lvalue_reference<_Predicate>::type>
36573e519524SHoward Hinnant                             (__first, __last, __pred, typename iterator_traits<_ForwardIterator>::iterator_category());
36583e519524SHoward Hinnant}
36593e519524SHoward Hinnant
36603e519524SHoward Hinnant// is_sorted_until
36613e519524SHoward Hinnant
36623e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Compare>
36631362d7efSNico Weber_LIBCPP_NODISCARD_EXT _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
36643e519524SHoward Hinnantis_sorted_until(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp)
36653e519524SHoward Hinnant{
36663e519524SHoward Hinnant    if (__first != __last)
36673e519524SHoward Hinnant    {
36683e519524SHoward Hinnant        _ForwardIterator __i = __first;
36693e519524SHoward Hinnant        while (++__i != __last)
36703e519524SHoward Hinnant        {
36713e519524SHoward Hinnant            if (__comp(*__i, *__first))
36723e519524SHoward Hinnant                return __i;
36733e519524SHoward Hinnant            __first = __i;
36743e519524SHoward Hinnant        }
36753e519524SHoward Hinnant    }
36763e519524SHoward Hinnant    return __last;
36773e519524SHoward Hinnant}
36783e519524SHoward Hinnant
36793e519524SHoward Hinnanttemplate<class _ForwardIterator>
36801362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
36811362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
36823e519524SHoward Hinnant_ForwardIterator
36833e519524SHoward Hinnantis_sorted_until(_ForwardIterator __first, _ForwardIterator __last)
36843e519524SHoward Hinnant{
3685ce48a113SHoward Hinnant    return _VSTD::is_sorted_until(__first, __last, __less<typename iterator_traits<_ForwardIterator>::value_type>());
36863e519524SHoward Hinnant}
36873e519524SHoward Hinnant
36883e519524SHoward Hinnant// is_sorted
36893e519524SHoward Hinnant
36903e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Compare>
36911362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
36921362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
36933e519524SHoward Hinnantbool
36943e519524SHoward Hinnantis_sorted(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp)
36953e519524SHoward Hinnant{
3696ce48a113SHoward Hinnant    return _VSTD::is_sorted_until(__first, __last, __comp) == __last;
36973e519524SHoward Hinnant}
36983e519524SHoward Hinnant
36993e519524SHoward Hinnanttemplate<class _ForwardIterator>
37001362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
37011362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
37023e519524SHoward Hinnantbool
37033e519524SHoward Hinnantis_sorted(_ForwardIterator __first, _ForwardIterator __last)
37043e519524SHoward Hinnant{
3705ce48a113SHoward Hinnant    return _VSTD::is_sorted(__first, __last, __less<typename iterator_traits<_ForwardIterator>::value_type>());
37063e519524SHoward Hinnant}
37073e519524SHoward Hinnant
37083e519524SHoward Hinnant// sort
37093e519524SHoward Hinnant
37103e519524SHoward Hinnant// stable, 2-3 compares, 0-2 swaps
37113e519524SHoward Hinnant
37123e519524SHoward Hinnanttemplate <class _Compare, class _ForwardIterator>
37133e519524SHoward Hinnantunsigned
37143e519524SHoward Hinnant__sort3(_ForwardIterator __x, _ForwardIterator __y, _ForwardIterator __z, _Compare __c)
37153e519524SHoward Hinnant{
37163e519524SHoward Hinnant    unsigned __r = 0;
37173e519524SHoward Hinnant    if (!__c(*__y, *__x))          // if x <= y
37183e519524SHoward Hinnant    {
37193e519524SHoward Hinnant        if (!__c(*__z, *__y))      // if y <= z
37203e519524SHoward Hinnant            return __r;            // x <= y && y <= z
37213e519524SHoward Hinnant                                   // x <= y && y > z
37223e519524SHoward Hinnant        swap(*__y, *__z);          // x <= z && y < z
37233e519524SHoward Hinnant        __r = 1;
37243e519524SHoward Hinnant        if (__c(*__y, *__x))       // if x > y
37253e519524SHoward Hinnant        {
37263e519524SHoward Hinnant            swap(*__x, *__y);      // x < y && y <= z
37273e519524SHoward Hinnant            __r = 2;
37283e519524SHoward Hinnant        }
37293e519524SHoward Hinnant        return __r;                // x <= y && y < z
37303e519524SHoward Hinnant    }
37313e519524SHoward Hinnant    if (__c(*__z, *__y))           // x > y, if y > z
37323e519524SHoward Hinnant    {
37333e519524SHoward Hinnant        swap(*__x, *__z);          // x < y && y < z
37343e519524SHoward Hinnant        __r = 1;
37353e519524SHoward Hinnant        return __r;
37363e519524SHoward Hinnant    }
37373e519524SHoward Hinnant    swap(*__x, *__y);              // x > y && y <= z
37383e519524SHoward Hinnant    __r = 1;                       // x < y && x <= z
37393e519524SHoward Hinnant    if (__c(*__z, *__y))           // if y > z
37403e519524SHoward Hinnant    {
37413e519524SHoward Hinnant        swap(*__y, *__z);          // x <= y && y < z
37423e519524SHoward Hinnant        __r = 2;
37433e519524SHoward Hinnant    }
37443e519524SHoward Hinnant    return __r;
37453e519524SHoward Hinnant}                                  // x <= y && y <= z
37463e519524SHoward Hinnant
37473e519524SHoward Hinnant// stable, 3-6 compares, 0-5 swaps
37483e519524SHoward Hinnant
37493e519524SHoward Hinnanttemplate <class _Compare, class _ForwardIterator>
37503e519524SHoward Hinnantunsigned
37513e519524SHoward Hinnant__sort4(_ForwardIterator __x1, _ForwardIterator __x2, _ForwardIterator __x3,
37523e519524SHoward Hinnant            _ForwardIterator __x4, _Compare __c)
37533e519524SHoward Hinnant{
37543e519524SHoward Hinnant    unsigned __r = __sort3<_Compare>(__x1, __x2, __x3, __c);
37553e519524SHoward Hinnant    if (__c(*__x4, *__x3))
37563e519524SHoward Hinnant    {
37573e519524SHoward Hinnant        swap(*__x3, *__x4);
37583e519524SHoward Hinnant        ++__r;
37593e519524SHoward Hinnant        if (__c(*__x3, *__x2))
37603e519524SHoward Hinnant        {
37613e519524SHoward Hinnant            swap(*__x2, *__x3);
37623e519524SHoward Hinnant            ++__r;
37633e519524SHoward Hinnant            if (__c(*__x2, *__x1))
37643e519524SHoward Hinnant            {
37653e519524SHoward Hinnant                swap(*__x1, *__x2);
37663e519524SHoward Hinnant                ++__r;
37673e519524SHoward Hinnant            }
37683e519524SHoward Hinnant        }
37693e519524SHoward Hinnant    }
37703e519524SHoward Hinnant    return __r;
37713e519524SHoward Hinnant}
37723e519524SHoward Hinnant
37733e519524SHoward Hinnant// stable, 4-10 compares, 0-9 swaps
37743e519524SHoward Hinnant
37753e519524SHoward Hinnanttemplate <class _Compare, class _ForwardIterator>
3776835140a4SLouis Dionne_LIBCPP_HIDDEN
37773e519524SHoward Hinnantunsigned
37783e519524SHoward Hinnant__sort5(_ForwardIterator __x1, _ForwardIterator __x2, _ForwardIterator __x3,
37793e519524SHoward Hinnant            _ForwardIterator __x4, _ForwardIterator __x5, _Compare __c)
37803e519524SHoward Hinnant{
37813e519524SHoward Hinnant    unsigned __r = __sort4<_Compare>(__x1, __x2, __x3, __x4, __c);
37823e519524SHoward Hinnant    if (__c(*__x5, *__x4))
37833e519524SHoward Hinnant    {
37843e519524SHoward Hinnant        swap(*__x4, *__x5);
37853e519524SHoward Hinnant        ++__r;
37863e519524SHoward Hinnant        if (__c(*__x4, *__x3))
37873e519524SHoward Hinnant        {
37883e519524SHoward Hinnant            swap(*__x3, *__x4);
37893e519524SHoward Hinnant            ++__r;
37903e519524SHoward Hinnant            if (__c(*__x3, *__x2))
37913e519524SHoward Hinnant            {
37923e519524SHoward Hinnant                swap(*__x2, *__x3);
37933e519524SHoward Hinnant                ++__r;
37943e519524SHoward Hinnant                if (__c(*__x2, *__x1))
37953e519524SHoward Hinnant                {
37963e519524SHoward Hinnant                    swap(*__x1, *__x2);
37973e519524SHoward Hinnant                    ++__r;
37983e519524SHoward Hinnant                }
37993e519524SHoward Hinnant            }
38003e519524SHoward Hinnant        }
38013e519524SHoward Hinnant    }
38023e519524SHoward Hinnant    return __r;
38033e519524SHoward Hinnant}
38043e519524SHoward Hinnant
38053e519524SHoward Hinnant// Assumes size > 0
38063e519524SHoward Hinnanttemplate <class _Compare, class _BirdirectionalIterator>
38073e519524SHoward Hinnantvoid
38083e519524SHoward Hinnant__selection_sort(_BirdirectionalIterator __first, _BirdirectionalIterator __last, _Compare __comp)
38093e519524SHoward Hinnant{
38103e519524SHoward Hinnant    _BirdirectionalIterator __lm1 = __last;
38113e519524SHoward Hinnant    for (--__lm1; __first != __lm1; ++__first)
38123e519524SHoward Hinnant    {
3813ce48a113SHoward Hinnant        _BirdirectionalIterator __i = _VSTD::min_element<_BirdirectionalIterator,
38143e519524SHoward Hinnant                                                        typename add_lvalue_reference<_Compare>::type>
38153e519524SHoward Hinnant                                                       (__first, __last, __comp);
38163e519524SHoward Hinnant        if (__i != __first)
38173e519524SHoward Hinnant            swap(*__first, *__i);
38183e519524SHoward Hinnant    }
38193e519524SHoward Hinnant}
38203e519524SHoward Hinnant
38213e519524SHoward Hinnanttemplate <class _Compare, class _BirdirectionalIterator>
38223e519524SHoward Hinnantvoid
38233e519524SHoward Hinnant__insertion_sort(_BirdirectionalIterator __first, _BirdirectionalIterator __last, _Compare __comp)
38243e519524SHoward Hinnant{
38253e519524SHoward Hinnant    typedef typename iterator_traits<_BirdirectionalIterator>::value_type value_type;
38263e519524SHoward Hinnant    if (__first != __last)
38273e519524SHoward Hinnant    {
38283e519524SHoward Hinnant        _BirdirectionalIterator __i = __first;
38293e519524SHoward Hinnant        for (++__i; __i != __last; ++__i)
38303e519524SHoward Hinnant        {
38313e519524SHoward Hinnant            _BirdirectionalIterator __j = __i;
3832ce48a113SHoward Hinnant            value_type __t(_VSTD::move(*__j));
38333e519524SHoward Hinnant            for (_BirdirectionalIterator __k = __i; __k != __first && __comp(__t,  *--__k); --__j)
3834ce48a113SHoward Hinnant                *__j = _VSTD::move(*__k);
3835ce48a113SHoward Hinnant            *__j = _VSTD::move(__t);
38363e519524SHoward Hinnant        }
38373e519524SHoward Hinnant    }
38383e519524SHoward Hinnant}
38393e519524SHoward Hinnant
38403e519524SHoward Hinnanttemplate <class _Compare, class _RandomAccessIterator>
38413e519524SHoward Hinnantvoid
38423e519524SHoward Hinnant__insertion_sort_3(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
38433e519524SHoward Hinnant{
38443e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
38453e519524SHoward Hinnant    _RandomAccessIterator __j = __first+2;
38463e519524SHoward Hinnant    __sort3<_Compare>(__first, __first+1, __j, __comp);
38473e519524SHoward Hinnant    for (_RandomAccessIterator __i = __j+1; __i != __last; ++__i)
38483e519524SHoward Hinnant    {
38493e519524SHoward Hinnant        if (__comp(*__i, *__j))
38503e519524SHoward Hinnant        {
3851ce48a113SHoward Hinnant            value_type __t(_VSTD::move(*__i));
38523e519524SHoward Hinnant            _RandomAccessIterator __k = __j;
38533e519524SHoward Hinnant            __j = __i;
38543e519524SHoward Hinnant            do
38553e519524SHoward Hinnant            {
3856ce48a113SHoward Hinnant                *__j = _VSTD::move(*__k);
38573e519524SHoward Hinnant                __j = __k;
38583e519524SHoward Hinnant            } while (__j != __first && __comp(__t, *--__k));
3859ce48a113SHoward Hinnant            *__j = _VSTD::move(__t);
38603e519524SHoward Hinnant        }
38613e519524SHoward Hinnant        __j = __i;
38623e519524SHoward Hinnant    }
38633e519524SHoward Hinnant}
38643e519524SHoward Hinnant
38653e519524SHoward Hinnanttemplate <class _Compare, class _RandomAccessIterator>
38663e519524SHoward Hinnantbool
38673e519524SHoward Hinnant__insertion_sort_incomplete(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
38683e519524SHoward Hinnant{
38693e519524SHoward Hinnant    switch (__last - __first)
38703e519524SHoward Hinnant    {
38713e519524SHoward Hinnant    case 0:
38723e519524SHoward Hinnant    case 1:
38733e519524SHoward Hinnant        return true;
38743e519524SHoward Hinnant    case 2:
38753e519524SHoward Hinnant        if (__comp(*--__last, *__first))
38763e519524SHoward Hinnant            swap(*__first, *__last);
38773e519524SHoward Hinnant        return true;
38783e519524SHoward Hinnant    case 3:
3879ce48a113SHoward Hinnant        _VSTD::__sort3<_Compare>(__first, __first+1, --__last, __comp);
38803e519524SHoward Hinnant        return true;
38813e519524SHoward Hinnant    case 4:
3882ce48a113SHoward Hinnant        _VSTD::__sort4<_Compare>(__first, __first+1, __first+2, --__last, __comp);
38833e519524SHoward Hinnant        return true;
38843e519524SHoward Hinnant    case 5:
3885ce48a113SHoward Hinnant        _VSTD::__sort5<_Compare>(__first, __first+1, __first+2, __first+3, --__last, __comp);
38863e519524SHoward Hinnant        return true;
38873e519524SHoward Hinnant    }
38883e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
38893e519524SHoward Hinnant    _RandomAccessIterator __j = __first+2;
38903e519524SHoward Hinnant    __sort3<_Compare>(__first, __first+1, __j, __comp);
38913e519524SHoward Hinnant    const unsigned __limit = 8;
38923e519524SHoward Hinnant    unsigned __count = 0;
38933e519524SHoward Hinnant    for (_RandomAccessIterator __i = __j+1; __i != __last; ++__i)
38943e519524SHoward Hinnant    {
38953e519524SHoward Hinnant        if (__comp(*__i, *__j))
38963e519524SHoward Hinnant        {
3897ce48a113SHoward Hinnant            value_type __t(_VSTD::move(*__i));
38983e519524SHoward Hinnant            _RandomAccessIterator __k = __j;
38993e519524SHoward Hinnant            __j = __i;
39003e519524SHoward Hinnant            do
39013e519524SHoward Hinnant            {
3902ce48a113SHoward Hinnant                *__j = _VSTD::move(*__k);
39033e519524SHoward Hinnant                __j = __k;
39043e519524SHoward Hinnant            } while (__j != __first && __comp(__t, *--__k));
3905ce48a113SHoward Hinnant            *__j = _VSTD::move(__t);
39063e519524SHoward Hinnant            if (++__count == __limit)
39073e519524SHoward Hinnant                return ++__i == __last;
39083e519524SHoward Hinnant        }
39093e519524SHoward Hinnant        __j = __i;
39103e519524SHoward Hinnant    }
39113e519524SHoward Hinnant    return true;
39123e519524SHoward Hinnant}
39133e519524SHoward Hinnant
39143e519524SHoward Hinnanttemplate <class _Compare, class _BirdirectionalIterator>
39153e519524SHoward Hinnantvoid
39163e519524SHoward Hinnant__insertion_sort_move(_BirdirectionalIterator __first1, _BirdirectionalIterator __last1,
39173e519524SHoward Hinnant                      typename iterator_traits<_BirdirectionalIterator>::value_type* __first2, _Compare __comp)
39183e519524SHoward Hinnant{
39193e519524SHoward Hinnant    typedef typename iterator_traits<_BirdirectionalIterator>::value_type value_type;
39203e519524SHoward Hinnant    if (__first1 != __last1)
39213e519524SHoward Hinnant    {
39223e519524SHoward Hinnant        __destruct_n __d(0);
39233e519524SHoward Hinnant        unique_ptr<value_type, __destruct_n&> __h(__first2, __d);
39243e519524SHoward Hinnant        value_type* __last2 = __first2;
3925ce48a113SHoward Hinnant        ::new(__last2) value_type(_VSTD::move(*__first1));
39263e519524SHoward Hinnant        __d.__incr((value_type*)0);
39273e519524SHoward Hinnant        for (++__last2; ++__first1 != __last1; ++__last2)
39283e519524SHoward Hinnant        {
39293e519524SHoward Hinnant            value_type* __j2 = __last2;
39303e519524SHoward Hinnant            value_type* __i2 = __j2;
39313e519524SHoward Hinnant            if (__comp(*__first1, *--__i2))
39323e519524SHoward Hinnant            {
3933ce48a113SHoward Hinnant                ::new(__j2) value_type(_VSTD::move(*__i2));
39343e519524SHoward Hinnant                __d.__incr((value_type*)0);
39353e519524SHoward Hinnant                for (--__j2; __i2 != __first2 && __comp(*__first1,  *--__i2); --__j2)
3936ce48a113SHoward Hinnant                    *__j2 = _VSTD::move(*__i2);
3937ce48a113SHoward Hinnant                *__j2 = _VSTD::move(*__first1);
39383e519524SHoward Hinnant            }
39393e519524SHoward Hinnant            else
39403e519524SHoward Hinnant            {
3941ce48a113SHoward Hinnant                ::new(__j2) value_type(_VSTD::move(*__first1));
39423e519524SHoward Hinnant                __d.__incr((value_type*)0);
39433e519524SHoward Hinnant            }
39443e519524SHoward Hinnant        }
39453e519524SHoward Hinnant        __h.release();
39463e519524SHoward Hinnant    }
39473e519524SHoward Hinnant}
39483e519524SHoward Hinnant
39493e519524SHoward Hinnanttemplate <class _Compare, class _RandomAccessIterator>
39503e519524SHoward Hinnantvoid
39513e519524SHoward Hinnant__sort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
39523e519524SHoward Hinnant{
39533e519524SHoward Hinnant    // _Compare is known to be a reference type
39543e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
39553e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
3956ca740483SHoward Hinnant    const difference_type __limit = is_trivially_copy_constructible<value_type>::value &&
3957ca740483SHoward Hinnant                                    is_trivially_copy_assignable<value_type>::value ? 30 : 6;
39583e519524SHoward Hinnant    while (true)
39593e519524SHoward Hinnant    {
39603e519524SHoward Hinnant    __restart:
39613e519524SHoward Hinnant        difference_type __len = __last - __first;
39623e519524SHoward Hinnant        switch (__len)
39633e519524SHoward Hinnant        {
39643e519524SHoward Hinnant        case 0:
39653e519524SHoward Hinnant        case 1:
39663e519524SHoward Hinnant            return;
39673e519524SHoward Hinnant        case 2:
39683e519524SHoward Hinnant            if (__comp(*--__last, *__first))
39693e519524SHoward Hinnant                swap(*__first, *__last);
39703e519524SHoward Hinnant            return;
39713e519524SHoward Hinnant        case 3:
3972ce48a113SHoward Hinnant            _VSTD::__sort3<_Compare>(__first, __first+1, --__last, __comp);
39733e519524SHoward Hinnant            return;
39743e519524SHoward Hinnant        case 4:
3975ce48a113SHoward Hinnant            _VSTD::__sort4<_Compare>(__first, __first+1, __first+2, --__last, __comp);
39763e519524SHoward Hinnant            return;
39773e519524SHoward Hinnant        case 5:
3978ce48a113SHoward Hinnant            _VSTD::__sort5<_Compare>(__first, __first+1, __first+2, __first+3, --__last, __comp);
39793e519524SHoward Hinnant            return;
39803e519524SHoward Hinnant        }
39813e519524SHoward Hinnant        if (__len <= __limit)
39823e519524SHoward Hinnant        {
3983ce48a113SHoward Hinnant            _VSTD::__insertion_sort_3<_Compare>(__first, __last, __comp);
39843e519524SHoward Hinnant            return;
39853e519524SHoward Hinnant        }
39863e519524SHoward Hinnant        // __len > 5
39873e519524SHoward Hinnant        _RandomAccessIterator __m = __first;
39883e519524SHoward Hinnant        _RandomAccessIterator __lm1 = __last;
39893e519524SHoward Hinnant        --__lm1;
39903e519524SHoward Hinnant        unsigned __n_swaps;
39913e519524SHoward Hinnant        {
39923e519524SHoward Hinnant        difference_type __delta;
39933e519524SHoward Hinnant        if (__len >= 1000)
39943e519524SHoward Hinnant        {
39953e519524SHoward Hinnant            __delta = __len/2;
39963e519524SHoward Hinnant            __m += __delta;
39973e519524SHoward Hinnant            __delta /= 2;
3998ce48a113SHoward Hinnant            __n_swaps = _VSTD::__sort5<_Compare>(__first, __first + __delta, __m, __m+__delta, __lm1, __comp);
39993e519524SHoward Hinnant        }
40003e519524SHoward Hinnant        else
40013e519524SHoward Hinnant        {
40023e519524SHoward Hinnant            __delta = __len/2;
40033e519524SHoward Hinnant            __m += __delta;
4004ce48a113SHoward Hinnant            __n_swaps = _VSTD::__sort3<_Compare>(__first, __m, __lm1, __comp);
40053e519524SHoward Hinnant        }
40063e519524SHoward Hinnant        }
40073e519524SHoward Hinnant        // *__m is median
40083e519524SHoward Hinnant        // partition [__first, __m) < *__m and *__m <= [__m, __last)
40093e519524SHoward Hinnant        // (this inhibits tossing elements equivalent to __m around unnecessarily)
40103e519524SHoward Hinnant        _RandomAccessIterator __i = __first;
40113e519524SHoward Hinnant        _RandomAccessIterator __j = __lm1;
40123e519524SHoward Hinnant        // j points beyond range to be tested, *__m is known to be <= *__lm1
40133e519524SHoward Hinnant        // The search going up is known to be guarded but the search coming down isn't.
40143e519524SHoward Hinnant        // Prime the downward search with a guard.
40153e519524SHoward Hinnant        if (!__comp(*__i, *__m))  // if *__first == *__m
40163e519524SHoward Hinnant        {
40173e519524SHoward Hinnant            // *__first == *__m, *__first doesn't go in first part
40183e519524SHoward Hinnant            // manually guard downward moving __j against __i
40193e519524SHoward Hinnant            while (true)
40203e519524SHoward Hinnant            {
40213e519524SHoward Hinnant                if (__i == --__j)
40223e519524SHoward Hinnant                {
40233e519524SHoward Hinnant                    // *__first == *__m, *__m <= all other elements
40243e519524SHoward Hinnant                    // Parition instead into [__first, __i) == *__first and *__first < [__i, __last)
40253e519524SHoward Hinnant                    ++__i;  // __first + 1
40263e519524SHoward Hinnant                    __j = __last;
40273e519524SHoward Hinnant                    if (!__comp(*__first, *--__j))  // we need a guard if *__first == *(__last-1)
40283e519524SHoward Hinnant                    {
40293e519524SHoward Hinnant                        while (true)
40303e519524SHoward Hinnant                        {
40313e519524SHoward Hinnant                            if (__i == __j)
40323e519524SHoward Hinnant                                return;  // [__first, __last) all equivalent elements
40333e519524SHoward Hinnant                            if (__comp(*__first, *__i))
40343e519524SHoward Hinnant                            {
40353e519524SHoward Hinnant                                swap(*__i, *__j);
40363e519524SHoward Hinnant                                ++__n_swaps;
40373e519524SHoward Hinnant                                ++__i;
40383e519524SHoward Hinnant                                break;
40393e519524SHoward Hinnant                            }
40403e519524SHoward Hinnant                            ++__i;
40413e519524SHoward Hinnant                        }
40423e519524SHoward Hinnant                    }
40433e519524SHoward Hinnant                    // [__first, __i) == *__first and *__first < [__j, __last) and __j == __last - 1
40443e519524SHoward Hinnant                    if (__i == __j)
40453e519524SHoward Hinnant                        return;
40463e519524SHoward Hinnant                    while (true)
40473e519524SHoward Hinnant                    {
40483e519524SHoward Hinnant                        while (!__comp(*__first, *__i))
40493e519524SHoward Hinnant                            ++__i;
40503e519524SHoward Hinnant                        while (__comp(*__first, *--__j))
40513e519524SHoward Hinnant                            ;
40523e519524SHoward Hinnant                        if (__i >= __j)
40533e519524SHoward Hinnant                            break;
40543e519524SHoward Hinnant                        swap(*__i, *__j);
40553e519524SHoward Hinnant                        ++__n_swaps;
40563e519524SHoward Hinnant                        ++__i;
40573e519524SHoward Hinnant                    }
40583e519524SHoward Hinnant                    // [__first, __i) == *__first and *__first < [__i, __last)
40593e519524SHoward Hinnant                    // The first part is sorted, sort the secod part
4060ce48a113SHoward Hinnant                    // _VSTD::__sort<_Compare>(__i, __last, __comp);
40613e519524SHoward Hinnant                    __first = __i;
40623e519524SHoward Hinnant                    goto __restart;
40633e519524SHoward Hinnant                }
40643e519524SHoward Hinnant                if (__comp(*__j, *__m))
40653e519524SHoward Hinnant                {
40663e519524SHoward Hinnant                    swap(*__i, *__j);
40673e519524SHoward Hinnant                    ++__n_swaps;
40683e519524SHoward Hinnant                    break;  // found guard for downward moving __j, now use unguarded partition
40693e519524SHoward Hinnant                }
40703e519524SHoward Hinnant            }
40713e519524SHoward Hinnant        }
40723e519524SHoward Hinnant        // It is known that *__i < *__m
40733e519524SHoward Hinnant        ++__i;
40743e519524SHoward Hinnant        // j points beyond range to be tested, *__m is known to be <= *__lm1
40753e519524SHoward Hinnant        // if not yet partitioned...
40763e519524SHoward Hinnant        if (__i < __j)
40773e519524SHoward Hinnant        {
40783e519524SHoward Hinnant            // known that *(__i - 1) < *__m
40793e519524SHoward Hinnant            // known that __i <= __m
40803e519524SHoward Hinnant            while (true)
40813e519524SHoward Hinnant            {
40823e519524SHoward Hinnant                // __m still guards upward moving __i
40833e519524SHoward Hinnant                while (__comp(*__i, *__m))
40843e519524SHoward Hinnant                    ++__i;
40853e519524SHoward Hinnant                // It is now known that a guard exists for downward moving __j
40863e519524SHoward Hinnant                while (!__comp(*--__j, *__m))
40873e519524SHoward Hinnant                    ;
40883e519524SHoward Hinnant                if (__i > __j)
40893e519524SHoward Hinnant                    break;
40903e519524SHoward Hinnant                swap(*__i, *__j);
40913e519524SHoward Hinnant                ++__n_swaps;
40923e519524SHoward Hinnant                // It is known that __m != __j
40933e519524SHoward Hinnant                // If __m just moved, follow it
40943e519524SHoward Hinnant                if (__m == __i)
40953e519524SHoward Hinnant                    __m = __j;
40963e519524SHoward Hinnant                ++__i;
40973e519524SHoward Hinnant            }
40983e519524SHoward Hinnant        }
40993e519524SHoward Hinnant        // [__first, __i) < *__m and *__m <= [__i, __last)
41003e519524SHoward Hinnant        if (__i != __m && __comp(*__m, *__i))
41013e519524SHoward Hinnant        {
41023e519524SHoward Hinnant            swap(*__i, *__m);
41033e519524SHoward Hinnant            ++__n_swaps;
41043e519524SHoward Hinnant        }
41053e519524SHoward Hinnant        // [__first, __i) < *__i and *__i <= [__i+1, __last)
41063e519524SHoward Hinnant        // If we were given a perfect partition, see if insertion sort is quick...
41073e519524SHoward Hinnant        if (__n_swaps == 0)
41083e519524SHoward Hinnant        {
4109ce48a113SHoward Hinnant            bool __fs = _VSTD::__insertion_sort_incomplete<_Compare>(__first, __i, __comp);
4110ce48a113SHoward Hinnant            if (_VSTD::__insertion_sort_incomplete<_Compare>(__i+1, __last, __comp))
41113e519524SHoward Hinnant            {
41123e519524SHoward Hinnant                if (__fs)
41133e519524SHoward Hinnant                    return;
41143e519524SHoward Hinnant                __last = __i;
41153e519524SHoward Hinnant                continue;
41163e519524SHoward Hinnant            }
41173e519524SHoward Hinnant            else
41183e519524SHoward Hinnant            {
41193e519524SHoward Hinnant                if (__fs)
41203e519524SHoward Hinnant                {
41213e519524SHoward Hinnant                    __first = ++__i;
41223e519524SHoward Hinnant                    continue;
41233e519524SHoward Hinnant                }
41243e519524SHoward Hinnant            }
41253e519524SHoward Hinnant        }
41263e519524SHoward Hinnant        // sort smaller range with recursive call and larger with tail recursion elimination
41273e519524SHoward Hinnant        if (__i - __first < __last - __i)
41283e519524SHoward Hinnant        {
4129ce48a113SHoward Hinnant            _VSTD::__sort<_Compare>(__first, __i, __comp);
4130ce48a113SHoward Hinnant            // _VSTD::__sort<_Compare>(__i+1, __last, __comp);
41313e519524SHoward Hinnant            __first = ++__i;
41323e519524SHoward Hinnant        }
41333e519524SHoward Hinnant        else
41343e519524SHoward Hinnant        {
4135ce48a113SHoward Hinnant            _VSTD::__sort<_Compare>(__i+1, __last, __comp);
4136ce48a113SHoward Hinnant            // _VSTD::__sort<_Compare>(__first, __i, __comp);
41373e519524SHoward Hinnant            __last = __i;
41383e519524SHoward Hinnant        }
41393e519524SHoward Hinnant    }
41403e519524SHoward Hinnant}
41413e519524SHoward Hinnant
41423e519524SHoward Hinnant// This forwarder keeps the top call and the recursive calls using the same instantiation, forcing a reference _Compare
41433e519524SHoward Hinnanttemplate <class _RandomAccessIterator, class _Compare>
41443e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
41453e519524SHoward Hinnantvoid
41463e519524SHoward Hinnantsort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
41473e519524SHoward Hinnant{
4148aa1cad15SEric Fiselier    typedef typename __comp_ref_type<_Compare>::type _Comp_ref;
4149aa1cad15SEric Fiselier    _VSTD::__sort<_Comp_ref>(__first, __last, _Comp_ref(__comp));
41503e519524SHoward Hinnant}
41513e519524SHoward Hinnant
41523e519524SHoward Hinnanttemplate <class _RandomAccessIterator>
41533e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
41543e519524SHoward Hinnantvoid
41553e519524SHoward Hinnantsort(_RandomAccessIterator __first, _RandomAccessIterator __last)
41563e519524SHoward Hinnant{
4157ce48a113SHoward Hinnant    _VSTD::sort(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
41583e519524SHoward Hinnant}
41593e519524SHoward Hinnant
41603e519524SHoward Hinnanttemplate <class _Tp>
41613e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
41623e519524SHoward Hinnantvoid
41633e519524SHoward Hinnantsort(_Tp** __first, _Tp** __last)
41643e519524SHoward Hinnant{
4165ce48a113SHoward Hinnant    _VSTD::sort((size_t*)__first, (size_t*)__last, __less<size_t>());
41663e519524SHoward Hinnant}
41673e519524SHoward Hinnant
41683e519524SHoward Hinnanttemplate <class _Tp>
41693e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
41703e519524SHoward Hinnantvoid
41713e519524SHoward Hinnantsort(__wrap_iter<_Tp*> __first, __wrap_iter<_Tp*> __last)
41723e519524SHoward Hinnant{
4173ce48a113SHoward Hinnant    _VSTD::sort(__first.base(), __last.base());
41743e519524SHoward Hinnant}
41753e519524SHoward Hinnant
4176f554add5SHoward Hinnanttemplate <class _Tp, class _Compare>
4177f554add5SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
4178f554add5SHoward Hinnantvoid
4179f554add5SHoward Hinnantsort(__wrap_iter<_Tp*> __first, __wrap_iter<_Tp*> __last, _Compare __comp)
4180f554add5SHoward Hinnant{
4181f554add5SHoward Hinnant    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
4182f554add5SHoward Hinnant    _VSTD::sort<_Tp*, _Comp_ref>(__first.base(), __last.base(), __comp);
4183f554add5SHoward Hinnant}
4184f554add5SHoward Hinnant
4185f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<char>&, char*>(char*, char*, __less<char>&))
4186f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<wchar_t>&, wchar_t*>(wchar_t*, wchar_t*, __less<wchar_t>&))
4187f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<signed char>&, signed char*>(signed char*, signed char*, __less<signed char>&))
4188f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<unsigned char>&, unsigned char*>(unsigned char*, unsigned char*, __less<unsigned char>&))
4189f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<short>&, short*>(short*, short*, __less<short>&))
4190f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<unsigned short>&, unsigned short*>(unsigned short*, unsigned short*, __less<unsigned short>&))
4191f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<int>&, int*>(int*, int*, __less<int>&))
4192f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<unsigned>&, unsigned*>(unsigned*, unsigned*, __less<unsigned>&))
4193f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<long>&, long*>(long*, long*, __less<long>&))
4194f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<unsigned long>&, unsigned long*>(unsigned long*, unsigned long*, __less<unsigned long>&))
4195f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<long long>&, long long*>(long long*, long long*, __less<long long>&))
4196f0544c20SHoward 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>&))
4197f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<float>&, float*>(float*, float*, __less<float>&))
4198f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<double>&, double*>(double*, double*, __less<double>&))
4199f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<long double>&, long double*>(long double*, long double*, __less<long double>&))
42003e519524SHoward Hinnant
4201f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<char>&, char*>(char*, char*, __less<char>&))
4202f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<wchar_t>&, wchar_t*>(wchar_t*, wchar_t*, __less<wchar_t>&))
4203f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<signed char>&, signed char*>(signed char*, signed char*, __less<signed char>&))
4204f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<unsigned char>&, unsigned char*>(unsigned char*, unsigned char*, __less<unsigned char>&))
4205f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<short>&, short*>(short*, short*, __less<short>&))
4206f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<unsigned short>&, unsigned short*>(unsigned short*, unsigned short*, __less<unsigned short>&))
4207f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<int>&, int*>(int*, int*, __less<int>&))
4208f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<unsigned>&, unsigned*>(unsigned*, unsigned*, __less<unsigned>&))
4209f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<long>&, long*>(long*, long*, __less<long>&))
4210f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<unsigned long>&, unsigned long*>(unsigned long*, unsigned long*, __less<unsigned long>&))
4211f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<long long>&, long long*>(long long*, long long*, __less<long long>&))
4212f0544c20SHoward 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>&))
4213f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<float>&, float*>(float*, float*, __less<float>&))
4214f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<double>&, double*>(double*, double*, __less<double>&))
4215f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<long double>&, long double*>(long double*, long double*, __less<long double>&))
42163e519524SHoward Hinnant
4217f0544c20SHoward 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>&))
42183e519524SHoward Hinnant
42193e519524SHoward Hinnant// lower_bound
42203e519524SHoward Hinnant
42213e519524SHoward Hinnanttemplate <class _Compare, class _ForwardIterator, class _Tp>
4222d57c03ddSMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
4223e4383379SHoward Hinnant__lower_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
42243e519524SHoward Hinnant{
42253e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator>::difference_type difference_type;
4226ce48a113SHoward Hinnant    difference_type __len = _VSTD::distance(__first, __last);
42273e519524SHoward Hinnant    while (__len != 0)
42283e519524SHoward Hinnant    {
422904695a75SLouis Dionne        difference_type __l2 = _VSTD::__half_positive(__len);
42303e519524SHoward Hinnant        _ForwardIterator __m = __first;
4231ce48a113SHoward Hinnant        _VSTD::advance(__m, __l2);
4232e4383379SHoward Hinnant        if (__comp(*__m, __value_))
42333e519524SHoward Hinnant        {
42343e519524SHoward Hinnant            __first = ++__m;
42353e519524SHoward Hinnant            __len -= __l2 + 1;
42363e519524SHoward Hinnant        }
42373e519524SHoward Hinnant        else
42383e519524SHoward Hinnant            __len = __l2;
42393e519524SHoward Hinnant    }
42403e519524SHoward Hinnant    return __first;
42413e519524SHoward Hinnant}
42423e519524SHoward Hinnant
42433e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Tp, class _Compare>
42441362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
42451362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
42463e519524SHoward Hinnant_ForwardIterator
4247e4383379SHoward Hinnantlower_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
42483e519524SHoward Hinnant{
42493e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
4250e4383379SHoward Hinnant    return __lower_bound<_Comp_ref>(__first, __last, __value_, __comp);
42513e519524SHoward Hinnant}
42523e519524SHoward Hinnant
42533e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Tp>
42541362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
42551362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
42563e519524SHoward Hinnant_ForwardIterator
4257e4383379SHoward Hinnantlower_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_)
42583e519524SHoward Hinnant{
4259e4383379SHoward Hinnant    return _VSTD::lower_bound(__first, __last, __value_,
42603e519524SHoward Hinnant                             __less<typename iterator_traits<_ForwardIterator>::value_type, _Tp>());
42613e519524SHoward Hinnant}
42623e519524SHoward Hinnant
42633e519524SHoward Hinnant// upper_bound
42643e519524SHoward Hinnant
42653e519524SHoward Hinnanttemplate <class _Compare, class _ForwardIterator, class _Tp>
4266d57c03ddSMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
4267e4383379SHoward Hinnant__upper_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
42683e519524SHoward Hinnant{
42693e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator>::difference_type difference_type;
4270ce48a113SHoward Hinnant    difference_type __len = _VSTD::distance(__first, __last);
42713e519524SHoward Hinnant    while (__len != 0)
42723e519524SHoward Hinnant    {
427304695a75SLouis Dionne        difference_type __l2 = _VSTD::__half_positive(__len);
42743e519524SHoward Hinnant        _ForwardIterator __m = __first;
4275ce48a113SHoward Hinnant        _VSTD::advance(__m, __l2);
4276e4383379SHoward Hinnant        if (__comp(__value_, *__m))
42773e519524SHoward Hinnant            __len = __l2;
42783e519524SHoward Hinnant        else
42793e519524SHoward Hinnant        {
42803e519524SHoward Hinnant            __first = ++__m;
42813e519524SHoward Hinnant            __len -= __l2 + 1;
42823e519524SHoward Hinnant        }
42833e519524SHoward Hinnant    }
42843e519524SHoward Hinnant    return __first;
42853e519524SHoward Hinnant}
42863e519524SHoward Hinnant
42873e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Tp, class _Compare>
42881362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
42891362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
42903e519524SHoward Hinnant_ForwardIterator
4291e4383379SHoward Hinnantupper_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
42923e519524SHoward Hinnant{
42933e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
4294e4383379SHoward Hinnant    return __upper_bound<_Comp_ref>(__first, __last, __value_, __comp);
42953e519524SHoward Hinnant}
42963e519524SHoward Hinnant
42973e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Tp>
42981362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
42991362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
43003e519524SHoward Hinnant_ForwardIterator
4301e4383379SHoward Hinnantupper_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_)
43023e519524SHoward Hinnant{
4303e4383379SHoward Hinnant    return _VSTD::upper_bound(__first, __last, __value_,
43043e519524SHoward Hinnant                             __less<_Tp, typename iterator_traits<_ForwardIterator>::value_type>());
43053e519524SHoward Hinnant}
43063e519524SHoward Hinnant
43073e519524SHoward Hinnant// equal_range
43083e519524SHoward Hinnant
43093e519524SHoward Hinnanttemplate <class _Compare, class _ForwardIterator, class _Tp>
4310d57c03ddSMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 pair<_ForwardIterator, _ForwardIterator>
4311e4383379SHoward Hinnant__equal_range(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
43123e519524SHoward Hinnant{
43133e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator>::difference_type difference_type;
4314ce48a113SHoward Hinnant    difference_type __len = _VSTD::distance(__first, __last);
43153e519524SHoward Hinnant    while (__len != 0)
43163e519524SHoward Hinnant    {
431704695a75SLouis Dionne        difference_type __l2 = _VSTD::__half_positive(__len);
43183e519524SHoward Hinnant        _ForwardIterator __m = __first;
4319ce48a113SHoward Hinnant        _VSTD::advance(__m, __l2);
4320e4383379SHoward Hinnant        if (__comp(*__m, __value_))
43213e519524SHoward Hinnant        {
43223e519524SHoward Hinnant            __first = ++__m;
43233e519524SHoward Hinnant            __len -= __l2 + 1;
43243e519524SHoward Hinnant        }
4325e4383379SHoward Hinnant        else if (__comp(__value_, *__m))
43263e519524SHoward Hinnant        {
43273e519524SHoward Hinnant            __last = __m;
43283e519524SHoward Hinnant            __len = __l2;
43293e519524SHoward Hinnant        }
43303e519524SHoward Hinnant        else
43313e519524SHoward Hinnant        {
43323e519524SHoward Hinnant            _ForwardIterator __mp1 = __m;
43333e519524SHoward Hinnant            return pair<_ForwardIterator, _ForwardIterator>
43343e519524SHoward Hinnant                   (
4335e4383379SHoward Hinnant                      __lower_bound<_Compare>(__first, __m, __value_, __comp),
4336e4383379SHoward Hinnant                      __upper_bound<_Compare>(++__mp1, __last, __value_, __comp)
43373e519524SHoward Hinnant                   );
43383e519524SHoward Hinnant        }
43393e519524SHoward Hinnant    }
43403e519524SHoward Hinnant    return pair<_ForwardIterator, _ForwardIterator>(__first, __first);
43413e519524SHoward Hinnant}
43423e519524SHoward Hinnant
43433e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Tp, class _Compare>
43441362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
43451362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
43463e519524SHoward Hinnantpair<_ForwardIterator, _ForwardIterator>
4347e4383379SHoward Hinnantequal_range(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
43483e519524SHoward Hinnant{
4349aa1cad15SEric Fiselier    typedef typename __comp_ref_type<_Compare>::type _Comp_ref;
4350e4383379SHoward Hinnant    return __equal_range<_Comp_ref>(__first, __last, __value_, __comp);
43513e519524SHoward Hinnant}
43523e519524SHoward Hinnant
43533e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Tp>
43541362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
43551362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
43563e519524SHoward Hinnantpair<_ForwardIterator, _ForwardIterator>
4357e4383379SHoward Hinnantequal_range(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_)
43583e519524SHoward Hinnant{
4359e4383379SHoward Hinnant    return _VSTD::equal_range(__first, __last, __value_,
43603e519524SHoward Hinnant                             __less<typename iterator_traits<_ForwardIterator>::value_type, _Tp>());
43613e519524SHoward Hinnant}
43623e519524SHoward Hinnant
43633e519524SHoward Hinnant// binary_search
43643e519524SHoward Hinnant
43653e519524SHoward Hinnanttemplate <class _Compare, class _ForwardIterator, class _Tp>
4366d57c03ddSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
43673e519524SHoward Hinnantbool
4368e4383379SHoward Hinnant__binary_search(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
43693e519524SHoward Hinnant{
4370e4383379SHoward Hinnant    __first = __lower_bound<_Compare>(__first, __last, __value_, __comp);
4371e4383379SHoward Hinnant    return __first != __last && !__comp(__value_, *__first);
43723e519524SHoward Hinnant}
43733e519524SHoward Hinnant
43743e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Tp, class _Compare>
43751362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
43761362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
43773e519524SHoward Hinnantbool
4378e4383379SHoward Hinnantbinary_search(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
43793e519524SHoward Hinnant{
4380aa1cad15SEric Fiselier    typedef typename __comp_ref_type<_Compare>::type _Comp_ref;
4381e4383379SHoward Hinnant    return __binary_search<_Comp_ref>(__first, __last, __value_, __comp);
43823e519524SHoward Hinnant}
43833e519524SHoward Hinnant
43843e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Tp>
43851362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
43861362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
43873e519524SHoward Hinnantbool
4388e4383379SHoward Hinnantbinary_search(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_)
43893e519524SHoward Hinnant{
4390e4383379SHoward Hinnant    return _VSTD::binary_search(__first, __last, __value_,
43913e519524SHoward Hinnant                             __less<typename iterator_traits<_ForwardIterator>::value_type, _Tp>());
43923e519524SHoward Hinnant}
43933e519524SHoward Hinnant
43943e519524SHoward Hinnant// merge
43953e519524SHoward Hinnant
43963e519524SHoward Hinnanttemplate <class _Compare, class _InputIterator1, class _InputIterator2, class _OutputIterator>
43973e519524SHoward Hinnant_OutputIterator
43983e519524SHoward Hinnant__merge(_InputIterator1 __first1, _InputIterator1 __last1,
43993e519524SHoward Hinnant        _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
44003e519524SHoward Hinnant{
44013e519524SHoward Hinnant    for (; __first1 != __last1; ++__result)
44023e519524SHoward Hinnant    {
44033e519524SHoward Hinnant        if (__first2 == __last2)
4404ce48a113SHoward Hinnant            return _VSTD::copy(__first1, __last1, __result);
44053e519524SHoward Hinnant        if (__comp(*__first2, *__first1))
44063e519524SHoward Hinnant        {
44073e519524SHoward Hinnant            *__result = *__first2;
44083e519524SHoward Hinnant            ++__first2;
44093e519524SHoward Hinnant        }
44103e519524SHoward Hinnant        else
44113e519524SHoward Hinnant        {
44123e519524SHoward Hinnant            *__result = *__first1;
44133e519524SHoward Hinnant            ++__first1;
44143e519524SHoward Hinnant        }
44153e519524SHoward Hinnant    }
4416ce48a113SHoward Hinnant    return _VSTD::copy(__first2, __last2, __result);
44173e519524SHoward Hinnant}
44183e519524SHoward Hinnant
44193e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
44203e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
44213e519524SHoward Hinnant_OutputIterator
44223e519524SHoward Hinnantmerge(_InputIterator1 __first1, _InputIterator1 __last1,
44233e519524SHoward Hinnant      _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
44243e519524SHoward Hinnant{
4425aa1cad15SEric Fiselier    typedef typename __comp_ref_type<_Compare>::type _Comp_ref;
4426ce48a113SHoward Hinnant    return _VSTD::__merge<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __comp);
44273e519524SHoward Hinnant}
44283e519524SHoward Hinnant
44293e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _OutputIterator>
44303e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
44313e519524SHoward Hinnant_OutputIterator
44323e519524SHoward Hinnantmerge(_InputIterator1 __first1, _InputIterator1 __last1,
44333e519524SHoward Hinnant      _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result)
44343e519524SHoward Hinnant{
44353e519524SHoward Hinnant    typedef typename iterator_traits<_InputIterator1>::value_type __v1;
44363e519524SHoward Hinnant    typedef typename iterator_traits<_InputIterator2>::value_type __v2;
44374f41779cSMarshall Clow    return _VSTD::merge(__first1, __last1, __first2, __last2, __result, __less<__v1, __v2>());
44383e519524SHoward Hinnant}
44393e519524SHoward Hinnant
44403e519524SHoward Hinnant// inplace_merge
44413e519524SHoward Hinnant
4442adfdae18SMarshall Clowtemplate <class _Compare, class _InputIterator1, class _InputIterator2,
4443adfdae18SMarshall Clow          class _OutputIterator>
4444adfdae18SMarshall Clowvoid __half_inplace_merge(_InputIterator1 __first1, _InputIterator1 __last1,
4445adfdae18SMarshall Clow                          _InputIterator2 __first2, _InputIterator2 __last2,
4446adfdae18SMarshall Clow                          _OutputIterator __result, _Compare __comp)
4447adfdae18SMarshall Clow{
4448adfdae18SMarshall Clow    for (; __first1 != __last1; ++__result)
4449adfdae18SMarshall Clow    {
4450adfdae18SMarshall Clow        if (__first2 == __last2)
4451adfdae18SMarshall Clow        {
4452adfdae18SMarshall Clow            _VSTD::move(__first1, __last1, __result);
4453adfdae18SMarshall Clow            return;
4454adfdae18SMarshall Clow        }
4455adfdae18SMarshall Clow
4456adfdae18SMarshall Clow        if (__comp(*__first2, *__first1))
4457adfdae18SMarshall Clow        {
4458adfdae18SMarshall Clow            *__result = _VSTD::move(*__first2);
4459adfdae18SMarshall Clow            ++__first2;
4460adfdae18SMarshall Clow        }
4461adfdae18SMarshall Clow        else
4462adfdae18SMarshall Clow        {
4463adfdae18SMarshall Clow            *__result = _VSTD::move(*__first1);
4464adfdae18SMarshall Clow            ++__first1;
4465adfdae18SMarshall Clow        }
4466adfdae18SMarshall Clow    }
4467adfdae18SMarshall Clow    // __first2 through __last2 are already in the right spot.
4468adfdae18SMarshall Clow}
4469adfdae18SMarshall Clow
44703e519524SHoward Hinnanttemplate <class _Compare, class _BidirectionalIterator>
44713e519524SHoward Hinnantvoid
44723e519524SHoward Hinnant__buffered_inplace_merge(_BidirectionalIterator __first, _BidirectionalIterator __middle, _BidirectionalIterator __last,
44733e519524SHoward Hinnant                _Compare __comp, typename iterator_traits<_BidirectionalIterator>::difference_type __len1,
44743e519524SHoward Hinnant                                 typename iterator_traits<_BidirectionalIterator>::difference_type __len2,
44753e519524SHoward Hinnant                typename iterator_traits<_BidirectionalIterator>::value_type* __buff)
44763e519524SHoward Hinnant{
44773e519524SHoward Hinnant    typedef typename iterator_traits<_BidirectionalIterator>::value_type value_type;
44783e519524SHoward Hinnant    __destruct_n __d(0);
44793e519524SHoward Hinnant    unique_ptr<value_type, __destruct_n&> __h2(__buff, __d);
44803e519524SHoward Hinnant    if (__len1 <= __len2)
44813e519524SHoward Hinnant    {
44823e519524SHoward Hinnant        value_type* __p = __buff;
44837fa68653SMarshall Clow        for (_BidirectionalIterator __i = __first; __i != __middle; __d.__incr((value_type*)0), (void) ++__i, (void) ++__p)
4484ce48a113SHoward Hinnant            ::new(__p) value_type(_VSTD::move(*__i));
4485adfdae18SMarshall Clow        __half_inplace_merge(__buff, __p, __middle, __last, __first, __comp);
44863e519524SHoward Hinnant    }
44873e519524SHoward Hinnant    else
44883e519524SHoward Hinnant    {
44893e519524SHoward Hinnant        value_type* __p = __buff;
44907fa68653SMarshall Clow        for (_BidirectionalIterator __i = __middle; __i != __last; __d.__incr((value_type*)0), (void) ++__i, (void) ++__p)
4491ce48a113SHoward Hinnant            ::new(__p) value_type(_VSTD::move(*__i));
44923e519524SHoward Hinnant        typedef reverse_iterator<_BidirectionalIterator> _RBi;
44933e519524SHoward Hinnant        typedef reverse_iterator<value_type*> _Rv;
4494adfdae18SMarshall Clow        __half_inplace_merge(_Rv(__p), _Rv(__buff),
4495adfdae18SMarshall Clow                             _RBi(__middle), _RBi(__first),
4496a763b36fSMarshall Clow                             _RBi(__last), __invert<_Compare>(__comp));
44973e519524SHoward Hinnant    }
44983e519524SHoward Hinnant}
44993e519524SHoward Hinnant
45003e519524SHoward Hinnanttemplate <class _Compare, class _BidirectionalIterator>
45013e519524SHoward Hinnantvoid
45023e519524SHoward Hinnant__inplace_merge(_BidirectionalIterator __first, _BidirectionalIterator __middle, _BidirectionalIterator __last,
45033e519524SHoward Hinnant                _Compare __comp, typename iterator_traits<_BidirectionalIterator>::difference_type __len1,
45043e519524SHoward Hinnant                                 typename iterator_traits<_BidirectionalIterator>::difference_type __len2,
45053e519524SHoward Hinnant                typename iterator_traits<_BidirectionalIterator>::value_type* __buff, ptrdiff_t __buff_size)
45063e519524SHoward Hinnant{
45073e519524SHoward Hinnant    typedef typename iterator_traits<_BidirectionalIterator>::difference_type difference_type;
45083e519524SHoward Hinnant    while (true)
45093e519524SHoward Hinnant    {
45103e519524SHoward Hinnant        // if __middle == __last, we're done
45113e519524SHoward Hinnant        if (__len2 == 0)
45123e519524SHoward Hinnant            return;
4513526e0929SMarshall Clow        if (__len1 <= __buff_size || __len2 <= __buff_size)
4514526e0929SMarshall Clow            return __buffered_inplace_merge<_Compare>
4515526e0929SMarshall Clow                   (__first, __middle, __last, __comp, __len1, __len2, __buff);
45163e519524SHoward Hinnant        // shrink [__first, __middle) as much as possible (with no moves), returning if it shrinks to 0
4517910285b2SEric Fiselier        for (; true; ++__first, (void) --__len1)
45183e519524SHoward Hinnant        {
45193e519524SHoward Hinnant            if (__len1 == 0)
45203e519524SHoward Hinnant                return;
45213e519524SHoward Hinnant            if (__comp(*__middle, *__first))
45223e519524SHoward Hinnant                break;
45233e519524SHoward Hinnant        }
45243e519524SHoward Hinnant        // __first < __middle < __last
45253e519524SHoward Hinnant        // *__first > *__middle
45263e519524SHoward Hinnant        // partition [__first, __m1) [__m1, __middle) [__middle, __m2) [__m2, __last) such that
45273e519524SHoward Hinnant        //     all elements in:
45283e519524SHoward Hinnant        //         [__first, __m1)  <= [__middle, __m2)
45293e519524SHoward Hinnant        //         [__middle, __m2) <  [__m1, __middle)
45303e519524SHoward Hinnant        //         [__m1, __middle) <= [__m2, __last)
45313e519524SHoward Hinnant        //     and __m1 or __m2 is in the middle of its range
45323e519524SHoward Hinnant        _BidirectionalIterator __m1;  // "median" of [__first, __middle)
45333e519524SHoward Hinnant        _BidirectionalIterator __m2;  // "median" of [__middle, __last)
45343e519524SHoward Hinnant        difference_type __len11;      // distance(__first, __m1)
45353e519524SHoward Hinnant        difference_type __len21;      // distance(__middle, __m2)
45363e519524SHoward Hinnant        // binary search smaller range
45373e519524SHoward Hinnant        if (__len1 < __len2)
45383e519524SHoward Hinnant        {   // __len >= 1, __len2 >= 2
45393e519524SHoward Hinnant            __len21 = __len2 / 2;
45403e519524SHoward Hinnant            __m2 = __middle;
4541ce48a113SHoward Hinnant            _VSTD::advance(__m2, __len21);
45423e519524SHoward Hinnant            __m1 = __upper_bound<_Compare>(__first, __middle, *__m2, __comp);
4543ce48a113SHoward Hinnant            __len11 = _VSTD::distance(__first, __m1);
45443e519524SHoward Hinnant        }
45453e519524SHoward Hinnant        else
45463e519524SHoward Hinnant        {
45473e519524SHoward Hinnant            if (__len1 == 1)
45483e519524SHoward Hinnant            {   // __len1 >= __len2 && __len2 > 0, therefore __len2 == 1
45493e519524SHoward Hinnant                // It is known *__first > *__middle
45503e519524SHoward Hinnant                swap(*__first, *__middle);
45513e519524SHoward Hinnant                return;
45523e519524SHoward Hinnant            }
45533e519524SHoward Hinnant            // __len1 >= 2, __len2 >= 1
45543e519524SHoward Hinnant            __len11 = __len1 / 2;
45553e519524SHoward Hinnant            __m1 = __first;
4556ce48a113SHoward Hinnant            _VSTD::advance(__m1, __len11);
45573e519524SHoward Hinnant            __m2 = __lower_bound<_Compare>(__middle, __last, *__m1, __comp);
4558ce48a113SHoward Hinnant            __len21 = _VSTD::distance(__middle, __m2);
45593e519524SHoward Hinnant        }
45603e519524SHoward Hinnant        difference_type __len12 = __len1 - __len11;  // distance(__m1, __middle)
45613e519524SHoward Hinnant        difference_type __len22 = __len2 - __len21;  // distance(__m2, __last)
45623e519524SHoward Hinnant        // [__first, __m1) [__m1, __middle) [__middle, __m2) [__m2, __last)
45633e519524SHoward Hinnant        // swap middle two partitions
4564ce48a113SHoward Hinnant        __middle = _VSTD::rotate(__m1, __middle, __m2);
45653e519524SHoward Hinnant        // __len12 and __len21 now have swapped meanings
45663e519524SHoward Hinnant        // merge smaller range with recurisve call and larger with tail recursion elimination
45673e519524SHoward Hinnant        if (__len11 + __len21 < __len12 + __len22)
45683e519524SHoward Hinnant        {
45693e519524SHoward Hinnant            __inplace_merge<_Compare>(__first, __m1, __middle, __comp, __len11, __len21, __buff, __buff_size);
45703e519524SHoward Hinnant//          __inplace_merge<_Compare>(__middle, __m2, __last, __comp, __len12, __len22, __buff, __buff_size);
45713e519524SHoward Hinnant            __first = __middle;
45723e519524SHoward Hinnant            __middle = __m2;
45733e519524SHoward Hinnant            __len1 = __len12;
45743e519524SHoward Hinnant            __len2 = __len22;
45753e519524SHoward Hinnant        }
45763e519524SHoward Hinnant        else
45773e519524SHoward Hinnant        {
45783e519524SHoward Hinnant            __inplace_merge<_Compare>(__middle, __m2, __last, __comp, __len12, __len22, __buff, __buff_size);
45793e519524SHoward Hinnant//          __inplace_merge<_Compare>(__first, __m1, __middle, __comp, __len11, __len21, __buff, __buff_size);
45803e519524SHoward Hinnant            __last = __middle;
45813e519524SHoward Hinnant            __middle = __m1;
45823e519524SHoward Hinnant            __len1 = __len11;
45833e519524SHoward Hinnant            __len2 = __len21;
45843e519524SHoward Hinnant        }
45853e519524SHoward Hinnant    }
45863e519524SHoward Hinnant}
45873e519524SHoward Hinnant
45883e519524SHoward Hinnanttemplate <class _BidirectionalIterator, class _Compare>
45893e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
45903e519524SHoward Hinnantvoid
45913e519524SHoward Hinnantinplace_merge(_BidirectionalIterator __first, _BidirectionalIterator __middle, _BidirectionalIterator __last,
45923e519524SHoward Hinnant              _Compare __comp)
45933e519524SHoward Hinnant{
45943e519524SHoward Hinnant    typedef typename iterator_traits<_BidirectionalIterator>::value_type value_type;
45953e519524SHoward Hinnant    typedef typename iterator_traits<_BidirectionalIterator>::difference_type difference_type;
4596ce48a113SHoward Hinnant    difference_type __len1 = _VSTD::distance(__first, __middle);
4597ce48a113SHoward Hinnant    difference_type __len2 = _VSTD::distance(__middle, __last);
4598ce48a113SHoward Hinnant    difference_type __buf_size = _VSTD::min(__len1, __len2);
45990b48cf9aSMarshall Clow    pair<value_type*, ptrdiff_t> __buf = _VSTD::get_temporary_buffer<value_type>(__buf_size);
46000b48cf9aSMarshall Clow    unique_ptr<value_type, __return_temporary_buffer> __h(__buf.first);
4601aa1cad15SEric Fiselier    typedef typename __comp_ref_type<_Compare>::type _Comp_ref;
4602ce48a113SHoward Hinnant    return _VSTD::__inplace_merge<_Comp_ref>(__first, __middle, __last, __comp, __len1, __len2,
46033e519524SHoward Hinnant                                            __buf.first, __buf.second);
46043e519524SHoward Hinnant}
46053e519524SHoward Hinnant
46063e519524SHoward Hinnanttemplate <class _BidirectionalIterator>
46073e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
46083e519524SHoward Hinnantvoid
46093e519524SHoward Hinnantinplace_merge(_BidirectionalIterator __first, _BidirectionalIterator __middle, _BidirectionalIterator __last)
46103e519524SHoward Hinnant{
4611ce48a113SHoward Hinnant    _VSTD::inplace_merge(__first, __middle, __last,
46123e519524SHoward Hinnant                        __less<typename iterator_traits<_BidirectionalIterator>::value_type>());
46133e519524SHoward Hinnant}
46143e519524SHoward Hinnant
46153e519524SHoward Hinnant// stable_sort
46163e519524SHoward Hinnant
46173e519524SHoward Hinnanttemplate <class _Compare, class _InputIterator1, class _InputIterator2>
46183e519524SHoward Hinnantvoid
46193e519524SHoward Hinnant__merge_move_construct(_InputIterator1 __first1, _InputIterator1 __last1,
46203e519524SHoward Hinnant        _InputIterator2 __first2, _InputIterator2 __last2,
46213e519524SHoward Hinnant        typename iterator_traits<_InputIterator1>::value_type* __result, _Compare __comp)
46223e519524SHoward Hinnant{
46233e519524SHoward Hinnant    typedef typename iterator_traits<_InputIterator1>::value_type value_type;
46243e519524SHoward Hinnant    __destruct_n __d(0);
46253e519524SHoward Hinnant    unique_ptr<value_type, __destruct_n&> __h(__result, __d);
46263e519524SHoward Hinnant    for (; true; ++__result)
46273e519524SHoward Hinnant    {
46283e519524SHoward Hinnant        if (__first1 == __last1)
46293e519524SHoward Hinnant        {
46307fa68653SMarshall Clow            for (; __first2 != __last2; ++__first2, ++__result, (void) __d.__incr((value_type*)0))
4631ce48a113SHoward Hinnant                ::new (__result) value_type(_VSTD::move(*__first2));
46323e519524SHoward Hinnant            __h.release();
46333e519524SHoward Hinnant            return;
46343e519524SHoward Hinnant        }
46353e519524SHoward Hinnant        if (__first2 == __last2)
46363e519524SHoward Hinnant        {
46377fa68653SMarshall Clow            for (; __first1 != __last1; ++__first1, ++__result, (void) __d.__incr((value_type*)0))
4638ce48a113SHoward Hinnant                ::new (__result) value_type(_VSTD::move(*__first1));
46393e519524SHoward Hinnant            __h.release();
46403e519524SHoward Hinnant            return;
46413e519524SHoward Hinnant        }
46423e519524SHoward Hinnant        if (__comp(*__first2, *__first1))
46433e519524SHoward Hinnant        {
4644ce48a113SHoward Hinnant            ::new (__result) value_type(_VSTD::move(*__first2));
46453e519524SHoward Hinnant            __d.__incr((value_type*)0);
46463e519524SHoward Hinnant            ++__first2;
46473e519524SHoward Hinnant        }
46483e519524SHoward Hinnant        else
46493e519524SHoward Hinnant        {
4650ce48a113SHoward Hinnant            ::new (__result) value_type(_VSTD::move(*__first1));
46513e519524SHoward Hinnant            __d.__incr((value_type*)0);
46523e519524SHoward Hinnant            ++__first1;
46533e519524SHoward Hinnant        }
46543e519524SHoward Hinnant    }
46553e519524SHoward Hinnant}
46563e519524SHoward Hinnant
46573e519524SHoward Hinnanttemplate <class _Compare, class _InputIterator1, class _InputIterator2, class _OutputIterator>
46583e519524SHoward Hinnantvoid
46593e519524SHoward Hinnant__merge_move_assign(_InputIterator1 __first1, _InputIterator1 __last1,
46603e519524SHoward Hinnant        _InputIterator2 __first2, _InputIterator2 __last2,
46613e519524SHoward Hinnant        _OutputIterator __result, _Compare __comp)
46623e519524SHoward Hinnant{
46633e519524SHoward Hinnant    for (; __first1 != __last1; ++__result)
46643e519524SHoward Hinnant    {
46653e519524SHoward Hinnant        if (__first2 == __last2)
46663e519524SHoward Hinnant        {
46677fa68653SMarshall Clow            for (; __first1 != __last1; ++__first1, (void) ++__result)
4668ce48a113SHoward Hinnant                *__result = _VSTD::move(*__first1);
46693e519524SHoward Hinnant            return;
46703e519524SHoward Hinnant        }
46713e519524SHoward Hinnant        if (__comp(*__first2, *__first1))
46723e519524SHoward Hinnant        {
4673ce48a113SHoward Hinnant            *__result = _VSTD::move(*__first2);
46743e519524SHoward Hinnant            ++__first2;
46753e519524SHoward Hinnant        }
46763e519524SHoward Hinnant        else
46773e519524SHoward Hinnant        {
4678ce48a113SHoward Hinnant            *__result = _VSTD::move(*__first1);
46793e519524SHoward Hinnant            ++__first1;
46803e519524SHoward Hinnant        }
46813e519524SHoward Hinnant    }
46827fa68653SMarshall Clow    for (; __first2 != __last2; ++__first2, (void) ++__result)
4683ce48a113SHoward Hinnant        *__result = _VSTD::move(*__first2);
46843e519524SHoward Hinnant}
46853e519524SHoward Hinnant
46863e519524SHoward Hinnanttemplate <class _Compare, class _RandomAccessIterator>
46873e519524SHoward Hinnantvoid
46883e519524SHoward Hinnant__stable_sort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp,
46893e519524SHoward Hinnant              typename iterator_traits<_RandomAccessIterator>::difference_type __len,
46903e519524SHoward Hinnant              typename iterator_traits<_RandomAccessIterator>::value_type* __buff, ptrdiff_t __buff_size);
46913e519524SHoward Hinnant
46923e519524SHoward Hinnanttemplate <class _Compare, class _RandomAccessIterator>
46933e519524SHoward Hinnantvoid
46943e519524SHoward Hinnant__stable_sort_move(_RandomAccessIterator __first1, _RandomAccessIterator __last1, _Compare __comp,
46953e519524SHoward Hinnant                   typename iterator_traits<_RandomAccessIterator>::difference_type __len,
46963e519524SHoward Hinnant                   typename iterator_traits<_RandomAccessIterator>::value_type* __first2)
46973e519524SHoward Hinnant{
46983e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
46993e519524SHoward Hinnant    switch (__len)
47003e519524SHoward Hinnant    {
47013e519524SHoward Hinnant    case 0:
47023e519524SHoward Hinnant        return;
47033e519524SHoward Hinnant    case 1:
4704ce48a113SHoward Hinnant        ::new(__first2) value_type(_VSTD::move(*__first1));
47053e519524SHoward Hinnant        return;
47063e519524SHoward Hinnant    case 2:
47073e519524SHoward Hinnant        __destruct_n __d(0);
47083e519524SHoward Hinnant        unique_ptr<value_type, __destruct_n&> __h2(__first2, __d);
47093e519524SHoward Hinnant        if (__comp(*--__last1, *__first1))
47103e519524SHoward Hinnant        {
4711ce48a113SHoward Hinnant            ::new(__first2) value_type(_VSTD::move(*__last1));
47123e519524SHoward Hinnant            __d.__incr((value_type*)0);
47133e519524SHoward Hinnant            ++__first2;
4714ce48a113SHoward Hinnant            ::new(__first2) value_type(_VSTD::move(*__first1));
47153e519524SHoward Hinnant        }
47163e519524SHoward Hinnant        else
47173e519524SHoward Hinnant        {
4718ce48a113SHoward Hinnant            ::new(__first2) value_type(_VSTD::move(*__first1));
47193e519524SHoward Hinnant            __d.__incr((value_type*)0);
47203e519524SHoward Hinnant            ++__first2;
4721ce48a113SHoward Hinnant            ::new(__first2) value_type(_VSTD::move(*__last1));
47223e519524SHoward Hinnant        }
47233e519524SHoward Hinnant        __h2.release();
47243e519524SHoward Hinnant        return;
47253e519524SHoward Hinnant    }
47263e519524SHoward Hinnant    if (__len <= 8)
47273e519524SHoward Hinnant    {
47283e519524SHoward Hinnant        __insertion_sort_move<_Compare>(__first1, __last1, __first2, __comp);
47293e519524SHoward Hinnant        return;
47303e519524SHoward Hinnant    }
47313e519524SHoward Hinnant    typename iterator_traits<_RandomAccessIterator>::difference_type __l2 = __len / 2;
47323e519524SHoward Hinnant    _RandomAccessIterator __m = __first1 + __l2;
47333e519524SHoward Hinnant    __stable_sort<_Compare>(__first1, __m, __comp, __l2, __first2, __l2);
47343e519524SHoward Hinnant    __stable_sort<_Compare>(__m, __last1, __comp, __len - __l2, __first2 + __l2, __len - __l2);
47353e519524SHoward Hinnant    __merge_move_construct<_Compare>(__first1, __m, __m, __last1, __first2, __comp);
47363e519524SHoward Hinnant}
47373e519524SHoward Hinnant
47383e519524SHoward Hinnanttemplate <class _Tp>
47393e519524SHoward Hinnantstruct __stable_sort_switch
47403e519524SHoward Hinnant{
4741ca740483SHoward Hinnant    static const unsigned value = 128*is_trivially_copy_assignable<_Tp>::value;
47423e519524SHoward Hinnant};
47433e519524SHoward Hinnant
47443e519524SHoward Hinnanttemplate <class _Compare, class _RandomAccessIterator>
47453e519524SHoward Hinnantvoid
47463e519524SHoward Hinnant__stable_sort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp,
47473e519524SHoward Hinnant              typename iterator_traits<_RandomAccessIterator>::difference_type __len,
47483e519524SHoward Hinnant              typename iterator_traits<_RandomAccessIterator>::value_type* __buff, ptrdiff_t __buff_size)
47493e519524SHoward Hinnant{
47503e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
47513e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
47523e519524SHoward Hinnant    switch (__len)
47533e519524SHoward Hinnant    {
47543e519524SHoward Hinnant    case 0:
47553e519524SHoward Hinnant    case 1:
47563e519524SHoward Hinnant        return;
47573e519524SHoward Hinnant    case 2:
47583e519524SHoward Hinnant        if (__comp(*--__last, *__first))
47593e519524SHoward Hinnant            swap(*__first, *__last);
47603e519524SHoward Hinnant        return;
47613e519524SHoward Hinnant    }
47623e519524SHoward Hinnant    if (__len <= static_cast<difference_type>(__stable_sort_switch<value_type>::value))
47633e519524SHoward Hinnant    {
47643e519524SHoward Hinnant        __insertion_sort<_Compare>(__first, __last, __comp);
47653e519524SHoward Hinnant        return;
47663e519524SHoward Hinnant    }
47673e519524SHoward Hinnant    typename iterator_traits<_RandomAccessIterator>::difference_type __l2 = __len / 2;
47683e519524SHoward Hinnant    _RandomAccessIterator __m = __first + __l2;
47693e519524SHoward Hinnant    if (__len <= __buff_size)
47703e519524SHoward Hinnant    {
47713e519524SHoward Hinnant        __destruct_n __d(0);
47723e519524SHoward Hinnant        unique_ptr<value_type, __destruct_n&> __h2(__buff, __d);
47733e519524SHoward Hinnant        __stable_sort_move<_Compare>(__first, __m, __comp, __l2, __buff);
47743e519524SHoward Hinnant        __d.__set(__l2, (value_type*)0);
47753e519524SHoward Hinnant        __stable_sort_move<_Compare>(__m, __last, __comp, __len - __l2, __buff + __l2);
47763e519524SHoward Hinnant        __d.__set(__len, (value_type*)0);
47773e519524SHoward Hinnant        __merge_move_assign<_Compare>(__buff, __buff + __l2, __buff + __l2, __buff + __len, __first, __comp);
47783e519524SHoward Hinnant//         __merge<_Compare>(move_iterator<value_type*>(__buff),
47793e519524SHoward Hinnant//                           move_iterator<value_type*>(__buff + __l2),
47803e519524SHoward Hinnant//                           move_iterator<_RandomAccessIterator>(__buff + __l2),
47813e519524SHoward Hinnant//                           move_iterator<_RandomAccessIterator>(__buff + __len),
47823e519524SHoward Hinnant//                           __first, __comp);
47833e519524SHoward Hinnant        return;
47843e519524SHoward Hinnant    }
47853e519524SHoward Hinnant    __stable_sort<_Compare>(__first, __m, __comp, __l2, __buff, __buff_size);
47863e519524SHoward Hinnant    __stable_sort<_Compare>(__m, __last, __comp, __len - __l2, __buff, __buff_size);
47873e519524SHoward Hinnant    __inplace_merge<_Compare>(__first, __m, __last, __comp, __l2, __len - __l2, __buff, __buff_size);
47883e519524SHoward Hinnant}
47893e519524SHoward Hinnant
47903e519524SHoward Hinnanttemplate <class _RandomAccessIterator, class _Compare>
47913e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
47923e519524SHoward Hinnantvoid
47933e519524SHoward Hinnantstable_sort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
47943e519524SHoward Hinnant{
47953e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
47963e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
47973e519524SHoward Hinnant    difference_type __len = __last - __first;
47983e519524SHoward Hinnant    pair<value_type*, ptrdiff_t> __buf(0, 0);
47993e519524SHoward Hinnant    unique_ptr<value_type, __return_temporary_buffer> __h;
48003e519524SHoward Hinnant    if (__len > static_cast<difference_type>(__stable_sort_switch<value_type>::value))
48013e519524SHoward Hinnant    {
4802ce48a113SHoward Hinnant        __buf = _VSTD::get_temporary_buffer<value_type>(__len);
48033e519524SHoward Hinnant        __h.reset(__buf.first);
48043e519524SHoward Hinnant    }
4805aa1cad15SEric Fiselier    typedef typename __comp_ref_type<_Compare>::type _Comp_ref;
48063e519524SHoward Hinnant    __stable_sort<_Comp_ref>(__first, __last, __comp, __len, __buf.first, __buf.second);
48073e519524SHoward Hinnant}
48083e519524SHoward Hinnant
48093e519524SHoward Hinnanttemplate <class _RandomAccessIterator>
48103e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
48113e519524SHoward Hinnantvoid
48123e519524SHoward Hinnantstable_sort(_RandomAccessIterator __first, _RandomAccessIterator __last)
48133e519524SHoward Hinnant{
4814ce48a113SHoward Hinnant    _VSTD::stable_sort(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
48153e519524SHoward Hinnant}
48163e519524SHoward Hinnant
48173e519524SHoward Hinnant// is_heap_until
48183e519524SHoward Hinnant
48193e519524SHoward Hinnanttemplate <class _RandomAccessIterator, class _Compare>
48201362d7efSNico Weber_LIBCPP_NODISCARD_EXT _LIBCPP_CONSTEXPR_AFTER_CXX17 _RandomAccessIterator
48213e519524SHoward Hinnantis_heap_until(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
48223e519524SHoward Hinnant{
4823ce48a113SHoward Hinnant    typedef typename _VSTD::iterator_traits<_RandomAccessIterator>::difference_type difference_type;
48243e519524SHoward Hinnant    difference_type __len = __last - __first;
48253e519524SHoward Hinnant    difference_type __p = 0;
48263e519524SHoward Hinnant    difference_type __c = 1;
48273e519524SHoward Hinnant    _RandomAccessIterator __pp = __first;
48283e519524SHoward Hinnant    while (__c < __len)
48293e519524SHoward Hinnant    {
48303e519524SHoward Hinnant        _RandomAccessIterator __cp = __first + __c;
48313e519524SHoward Hinnant        if (__comp(*__pp, *__cp))
48323e519524SHoward Hinnant            return __cp;
48333e519524SHoward Hinnant        ++__c;
48343e519524SHoward Hinnant        ++__cp;
48353e519524SHoward Hinnant        if (__c == __len)
48363e519524SHoward Hinnant            return __last;
48373e519524SHoward Hinnant        if (__comp(*__pp, *__cp))
48383e519524SHoward Hinnant            return __cp;
48393e519524SHoward Hinnant        ++__p;
48403e519524SHoward Hinnant        ++__pp;
48413e519524SHoward Hinnant        __c = 2 * __p + 1;
48423e519524SHoward Hinnant    }
48433e519524SHoward Hinnant    return __last;
48443e519524SHoward Hinnant}
48453e519524SHoward Hinnant
48463e519524SHoward Hinnanttemplate<class _RandomAccessIterator>
48471362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
48481362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
48493e519524SHoward Hinnant_RandomAccessIterator
48503e519524SHoward Hinnantis_heap_until(_RandomAccessIterator __first, _RandomAccessIterator __last)
48513e519524SHoward Hinnant{
4852ce48a113SHoward Hinnant    return _VSTD::is_heap_until(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
48533e519524SHoward Hinnant}
48543e519524SHoward Hinnant
48553e519524SHoward Hinnant// is_heap
48563e519524SHoward Hinnant
48573e519524SHoward Hinnanttemplate <class _RandomAccessIterator, class _Compare>
48581362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
48591362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
48603e519524SHoward Hinnantbool
48613e519524SHoward Hinnantis_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
48623e519524SHoward Hinnant{
4863ce48a113SHoward Hinnant    return _VSTD::is_heap_until(__first, __last, __comp) == __last;
48643e519524SHoward Hinnant}
48653e519524SHoward Hinnant
48663e519524SHoward Hinnanttemplate<class _RandomAccessIterator>
48671362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
48681362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
48693e519524SHoward Hinnantbool
48703e519524SHoward Hinnantis_heap(_RandomAccessIterator __first, _RandomAccessIterator __last)
48713e519524SHoward Hinnant{
4872ce48a113SHoward Hinnant    return _VSTD::is_heap(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
48733e519524SHoward Hinnant}
48743e519524SHoward Hinnant
48753e519524SHoward Hinnant// push_heap
48763e519524SHoward Hinnant
48773e519524SHoward Hinnanttemplate <class _Compare, class _RandomAccessIterator>
48783e519524SHoward Hinnantvoid
48798b512602SDavid Majnemer__sift_up(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp,
48803e519524SHoward Hinnant          typename iterator_traits<_RandomAccessIterator>::difference_type __len)
48813e519524SHoward Hinnant{
48823e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
48833e519524SHoward Hinnant    if (__len > 1)
48843e519524SHoward Hinnant    {
48853e519524SHoward Hinnant        __len = (__len - 2) / 2;
48863e519524SHoward Hinnant        _RandomAccessIterator __ptr = __first + __len;
48873e519524SHoward Hinnant        if (__comp(*__ptr, *--__last))
48883e519524SHoward Hinnant        {
4889ce48a113SHoward Hinnant            value_type __t(_VSTD::move(*__last));
48903e519524SHoward Hinnant            do
48913e519524SHoward Hinnant            {
4892ce48a113SHoward Hinnant                *__last = _VSTD::move(*__ptr);
48933e519524SHoward Hinnant                __last = __ptr;
48943e519524SHoward Hinnant                if (__len == 0)
48953e519524SHoward Hinnant                    break;
48963e519524SHoward Hinnant                __len = (__len - 1) / 2;
48973e519524SHoward Hinnant                __ptr = __first + __len;
48983e519524SHoward Hinnant            } while (__comp(*__ptr, __t));
4899ce48a113SHoward Hinnant            *__last = _VSTD::move(__t);
49003e519524SHoward Hinnant        }
49013e519524SHoward Hinnant    }
49023e519524SHoward Hinnant}
49033e519524SHoward Hinnant
49043e519524SHoward Hinnanttemplate <class _RandomAccessIterator, class _Compare>
49053e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
49063e519524SHoward Hinnantvoid
49073e519524SHoward Hinnantpush_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
49083e519524SHoward Hinnant{
4909aa1cad15SEric Fiselier    typedef typename __comp_ref_type<_Compare>::type _Comp_ref;
49108b512602SDavid Majnemer    __sift_up<_Comp_ref>(__first, __last, __comp, __last - __first);
49113e519524SHoward Hinnant}
49123e519524SHoward Hinnant
49133e519524SHoward Hinnanttemplate <class _RandomAccessIterator>
49143e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
49153e519524SHoward Hinnantvoid
49163e519524SHoward Hinnantpush_heap(_RandomAccessIterator __first, _RandomAccessIterator __last)
49173e519524SHoward Hinnant{
4918ce48a113SHoward Hinnant    _VSTD::push_heap(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
49193e519524SHoward Hinnant}
49203e519524SHoward Hinnant
49213e519524SHoward Hinnant// pop_heap
49223e519524SHoward Hinnant
49233e519524SHoward Hinnanttemplate <class _Compare, class _RandomAccessIterator>
49248b512602SDavid Majnemervoid
4925fd838227SEric Fiselier__sift_down(_RandomAccessIterator __first, _RandomAccessIterator /*__last*/,
4926fd838227SEric Fiselier            _Compare __comp,
49278b512602SDavid Majnemer            typename iterator_traits<_RandomAccessIterator>::difference_type __len,
49288b512602SDavid Majnemer            _RandomAccessIterator __start)
49298b512602SDavid Majnemer{
49308b512602SDavid Majnemer    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
49318b512602SDavid Majnemer    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
49328b512602SDavid Majnemer    // left-child of __start is at 2 * __start + 1
49338b512602SDavid Majnemer    // right-child of __start is at 2 * __start + 2
49348b512602SDavid Majnemer    difference_type __child = __start - __first;
49358b512602SDavid Majnemer
49368b512602SDavid Majnemer    if (__len < 2 || (__len - 2) / 2 < __child)
49378b512602SDavid Majnemer        return;
49388b512602SDavid Majnemer
49398b512602SDavid Majnemer    __child = 2 * __child + 1;
49408b512602SDavid Majnemer    _RandomAccessIterator __child_i = __first + __child;
49418b512602SDavid Majnemer
49428b512602SDavid Majnemer    if ((__child + 1) < __len && __comp(*__child_i, *(__child_i + 1))) {
49438b512602SDavid Majnemer        // right-child exists and is greater than left-child
49448b512602SDavid Majnemer        ++__child_i;
49458b512602SDavid Majnemer        ++__child;
49468b512602SDavid Majnemer    }
49478b512602SDavid Majnemer
49488b512602SDavid Majnemer    // check if we are in heap-order
49498b512602SDavid Majnemer    if (__comp(*__child_i, *__start))
49508b512602SDavid Majnemer        // we are, __start is larger than it's largest child
49518b512602SDavid Majnemer        return;
49528b512602SDavid Majnemer
49538b512602SDavid Majnemer    value_type __top(_VSTD::move(*__start));
49548b512602SDavid Majnemer    do
49558b512602SDavid Majnemer    {
49568b512602SDavid Majnemer        // we are not in heap-order, swap the parent with it's largest child
49578b512602SDavid Majnemer        *__start = _VSTD::move(*__child_i);
49588b512602SDavid Majnemer        __start = __child_i;
49598b512602SDavid Majnemer
49608b512602SDavid Majnemer        if ((__len - 2) / 2 < __child)
49618b512602SDavid Majnemer            break;
49628b512602SDavid Majnemer
49638b512602SDavid Majnemer        // recompute the child based off of the updated parent
49648b512602SDavid Majnemer        __child = 2 * __child + 1;
49658b512602SDavid Majnemer        __child_i = __first + __child;
49668b512602SDavid Majnemer
49678b512602SDavid Majnemer        if ((__child + 1) < __len && __comp(*__child_i, *(__child_i + 1))) {
49688b512602SDavid Majnemer            // right-child exists and is greater than left-child
49698b512602SDavid Majnemer            ++__child_i;
49708b512602SDavid Majnemer            ++__child;
49718b512602SDavid Majnemer        }
49728b512602SDavid Majnemer
49738b512602SDavid Majnemer        // check if we are in heap-order
49748b512602SDavid Majnemer    } while (!__comp(*__child_i, __top));
49758b512602SDavid Majnemer    *__start = _VSTD::move(__top);
49768b512602SDavid Majnemer}
49778b512602SDavid Majnemer
49788b512602SDavid Majnemertemplate <class _Compare, class _RandomAccessIterator>
49793e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
49803e519524SHoward Hinnantvoid
49813e519524SHoward Hinnant__pop_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp,
49823e519524SHoward Hinnant           typename iterator_traits<_RandomAccessIterator>::difference_type __len)
49833e519524SHoward Hinnant{
49843e519524SHoward Hinnant    if (__len > 1)
49853e519524SHoward Hinnant    {
49863e519524SHoward Hinnant        swap(*__first, *--__last);
49878b512602SDavid Majnemer        __sift_down<_Compare>(__first, __last, __comp, __len - 1, __first);
49883e519524SHoward Hinnant    }
49893e519524SHoward Hinnant}
49903e519524SHoward Hinnant
49913e519524SHoward Hinnanttemplate <class _RandomAccessIterator, class _Compare>
49923e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
49933e519524SHoward Hinnantvoid
49943e519524SHoward Hinnantpop_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
49953e519524SHoward Hinnant{
4996aa1cad15SEric Fiselier    typedef typename __comp_ref_type<_Compare>::type _Comp_ref;
49973e519524SHoward Hinnant    __pop_heap<_Comp_ref>(__first, __last, __comp, __last - __first);
49983e519524SHoward Hinnant}
49993e519524SHoward Hinnant
50003e519524SHoward Hinnanttemplate <class _RandomAccessIterator>
50013e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
50023e519524SHoward Hinnantvoid
50033e519524SHoward Hinnantpop_heap(_RandomAccessIterator __first, _RandomAccessIterator __last)
50043e519524SHoward Hinnant{
5005ce48a113SHoward Hinnant    _VSTD::pop_heap(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
50063e519524SHoward Hinnant}
50073e519524SHoward Hinnant
50083e519524SHoward Hinnant// make_heap
50093e519524SHoward Hinnant
50103e519524SHoward Hinnanttemplate <class _Compare, class _RandomAccessIterator>
50113e519524SHoward Hinnantvoid
50123e519524SHoward Hinnant__make_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
50133e519524SHoward Hinnant{
50143e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
50153e519524SHoward Hinnant    difference_type __n = __last - __first;
50163e519524SHoward Hinnant    if (__n > 1)
50173e519524SHoward Hinnant    {
50188b512602SDavid Majnemer        // start from the first parent, there is no need to consider children
50198b512602SDavid Majnemer        for (difference_type __start = (__n - 2) / 2; __start >= 0; --__start)
50208b512602SDavid Majnemer        {
50218b512602SDavid Majnemer            __sift_down<_Compare>(__first, __last, __comp, __n, __first + __start);
50228b512602SDavid Majnemer        }
50233e519524SHoward Hinnant    }
50243e519524SHoward Hinnant}
50253e519524SHoward Hinnant
50263e519524SHoward Hinnanttemplate <class _RandomAccessIterator, class _Compare>
50273e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
50283e519524SHoward Hinnantvoid
50293e519524SHoward Hinnantmake_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
50303e519524SHoward Hinnant{
5031aa1cad15SEric Fiselier    typedef typename __comp_ref_type<_Compare>::type _Comp_ref;
50323e519524SHoward Hinnant    __make_heap<_Comp_ref>(__first, __last, __comp);
50333e519524SHoward Hinnant}
50343e519524SHoward Hinnant
50353e519524SHoward Hinnanttemplate <class _RandomAccessIterator>
50363e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
50373e519524SHoward Hinnantvoid
50383e519524SHoward Hinnantmake_heap(_RandomAccessIterator __first, _RandomAccessIterator __last)
50393e519524SHoward Hinnant{
5040ce48a113SHoward Hinnant    _VSTD::make_heap(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
50413e519524SHoward Hinnant}
50423e519524SHoward Hinnant
50433e519524SHoward Hinnant// sort_heap
50443e519524SHoward Hinnant
50453e519524SHoward Hinnanttemplate <class _Compare, class _RandomAccessIterator>
50463e519524SHoward Hinnantvoid
50473e519524SHoward Hinnant__sort_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
50483e519524SHoward Hinnant{
50493e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
50507fa68653SMarshall Clow    for (difference_type __n = __last - __first; __n > 1; --__last, (void) --__n)
50513e519524SHoward Hinnant        __pop_heap<_Compare>(__first, __last, __comp, __n);
50523e519524SHoward Hinnant}
50533e519524SHoward Hinnant
50543e519524SHoward Hinnanttemplate <class _RandomAccessIterator, class _Compare>
50553e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
50563e519524SHoward Hinnantvoid
50573e519524SHoward Hinnantsort_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
50583e519524SHoward Hinnant{
5059aa1cad15SEric Fiselier    typedef typename __comp_ref_type<_Compare>::type _Comp_ref;
50603e519524SHoward Hinnant    __sort_heap<_Comp_ref>(__first, __last, __comp);
50613e519524SHoward Hinnant}
50623e519524SHoward Hinnant
50633e519524SHoward Hinnanttemplate <class _RandomAccessIterator>
50643e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
50653e519524SHoward Hinnantvoid
50663e519524SHoward Hinnantsort_heap(_RandomAccessIterator __first, _RandomAccessIterator __last)
50673e519524SHoward Hinnant{
5068ce48a113SHoward Hinnant    _VSTD::sort_heap(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
50693e519524SHoward Hinnant}
50703e519524SHoward Hinnant
50713e519524SHoward Hinnant// partial_sort
50723e519524SHoward Hinnant
50733e519524SHoward Hinnanttemplate <class _Compare, class _RandomAccessIterator>
50743e519524SHoward Hinnantvoid
50753e519524SHoward Hinnant__partial_sort(_RandomAccessIterator __first, _RandomAccessIterator __middle, _RandomAccessIterator __last,
50763e519524SHoward Hinnant             _Compare __comp)
50773e519524SHoward Hinnant{
50783e519524SHoward Hinnant    __make_heap<_Compare>(__first, __middle, __comp);
50793e519524SHoward Hinnant    typename iterator_traits<_RandomAccessIterator>::difference_type __len = __middle - __first;
50803e519524SHoward Hinnant    for (_RandomAccessIterator __i = __middle; __i != __last; ++__i)
50813e519524SHoward Hinnant    {
50823e519524SHoward Hinnant        if (__comp(*__i, *__first))
50833e519524SHoward Hinnant        {
50843e519524SHoward Hinnant            swap(*__i, *__first);
50858b512602SDavid Majnemer            __sift_down<_Compare>(__first, __middle, __comp, __len, __first);
50863e519524SHoward Hinnant        }
50873e519524SHoward Hinnant    }
50883e519524SHoward Hinnant    __sort_heap<_Compare>(__first, __middle, __comp);
50893e519524SHoward Hinnant}
50903e519524SHoward Hinnant
50913e519524SHoward Hinnanttemplate <class _RandomAccessIterator, class _Compare>
50923e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
50933e519524SHoward Hinnantvoid
50943e519524SHoward Hinnantpartial_sort(_RandomAccessIterator __first, _RandomAccessIterator __middle, _RandomAccessIterator __last,
50953e519524SHoward Hinnant             _Compare __comp)
50963e519524SHoward Hinnant{
5097aa1cad15SEric Fiselier    typedef typename __comp_ref_type<_Compare>::type _Comp_ref;
50983e519524SHoward Hinnant    __partial_sort<_Comp_ref>(__first, __middle, __last, __comp);
50993e519524SHoward Hinnant}
51003e519524SHoward Hinnant
51013e519524SHoward Hinnanttemplate <class _RandomAccessIterator>
51023e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
51033e519524SHoward Hinnantvoid
51043e519524SHoward Hinnantpartial_sort(_RandomAccessIterator __first, _RandomAccessIterator __middle, _RandomAccessIterator __last)
51053e519524SHoward Hinnant{
5106ce48a113SHoward Hinnant    _VSTD::partial_sort(__first, __middle, __last,
51073e519524SHoward Hinnant                       __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
51083e519524SHoward Hinnant}
51093e519524SHoward Hinnant
51103e519524SHoward Hinnant// partial_sort_copy
51113e519524SHoward Hinnant
51123e519524SHoward Hinnanttemplate <class _Compare, class _InputIterator, class _RandomAccessIterator>
51133e519524SHoward Hinnant_RandomAccessIterator
51143e519524SHoward Hinnant__partial_sort_copy(_InputIterator __first, _InputIterator __last,
51153e519524SHoward Hinnant                    _RandomAccessIterator __result_first, _RandomAccessIterator __result_last, _Compare __comp)
51163e519524SHoward Hinnant{
51173e519524SHoward Hinnant    _RandomAccessIterator __r = __result_first;
51183e519524SHoward Hinnant    if (__r != __result_last)
51193e519524SHoward Hinnant    {
51207fa68653SMarshall Clow        for (; __first != __last && __r != __result_last; ++__first, (void) ++__r)
51213e519524SHoward Hinnant            *__r = *__first;
51223e519524SHoward Hinnant        __make_heap<_Compare>(__result_first, __r, __comp);
51238b512602SDavid Majnemer        typename iterator_traits<_RandomAccessIterator>::difference_type __len = __r - __result_first;
51243e519524SHoward Hinnant        for (; __first != __last; ++__first)
51253e519524SHoward Hinnant            if (__comp(*__first, *__result_first))
51263e519524SHoward Hinnant            {
51273e519524SHoward Hinnant                *__result_first = *__first;
51288b512602SDavid Majnemer                __sift_down<_Compare>(__result_first, __r, __comp, __len, __result_first);
51293e519524SHoward Hinnant            }
51303e519524SHoward Hinnant        __sort_heap<_Compare>(__result_first, __r, __comp);
51313e519524SHoward Hinnant    }
51323e519524SHoward Hinnant    return __r;
51333e519524SHoward Hinnant}
51343e519524SHoward Hinnant
51353e519524SHoward Hinnanttemplate <class _InputIterator, class _RandomAccessIterator, class _Compare>
51363e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
51373e519524SHoward Hinnant_RandomAccessIterator
51383e519524SHoward Hinnantpartial_sort_copy(_InputIterator __first, _InputIterator __last,
51393e519524SHoward Hinnant                  _RandomAccessIterator __result_first, _RandomAccessIterator __result_last, _Compare __comp)
51403e519524SHoward Hinnant{
5141aa1cad15SEric Fiselier    typedef typename __comp_ref_type<_Compare>::type _Comp_ref;
51423e519524SHoward Hinnant    return __partial_sort_copy<_Comp_ref>(__first, __last, __result_first, __result_last, __comp);
51433e519524SHoward Hinnant}
51443e519524SHoward Hinnant
51453e519524SHoward Hinnanttemplate <class _InputIterator, class _RandomAccessIterator>
51463e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
51473e519524SHoward Hinnant_RandomAccessIterator
51483e519524SHoward Hinnantpartial_sort_copy(_InputIterator __first, _InputIterator __last,
51493e519524SHoward Hinnant                  _RandomAccessIterator __result_first, _RandomAccessIterator __result_last)
51503e519524SHoward Hinnant{
5151ce48a113SHoward Hinnant    return _VSTD::partial_sort_copy(__first, __last, __result_first, __result_last,
51523e519524SHoward Hinnant                                   __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
51533e519524SHoward Hinnant}
51543e519524SHoward Hinnant
51553e519524SHoward Hinnant// nth_element
51563e519524SHoward Hinnant
51573e519524SHoward Hinnanttemplate <class _Compare, class _RandomAccessIterator>
51583e519524SHoward Hinnantvoid
51593e519524SHoward Hinnant__nth_element(_RandomAccessIterator __first, _RandomAccessIterator __nth, _RandomAccessIterator __last, _Compare __comp)
51603e519524SHoward Hinnant{
51613e519524SHoward Hinnant    // _Compare is known to be a reference type
51623e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
51633e519524SHoward Hinnant    const difference_type __limit = 7;
51643e519524SHoward Hinnant    while (true)
51653e519524SHoward Hinnant    {
51663e519524SHoward Hinnant    __restart:
5167b34b4819SHoward Hinnant        if (__nth == __last)
5168b34b4819SHoward Hinnant            return;
51693e519524SHoward Hinnant        difference_type __len = __last - __first;
51703e519524SHoward Hinnant        switch (__len)
51713e519524SHoward Hinnant        {
51723e519524SHoward Hinnant        case 0:
51733e519524SHoward Hinnant        case 1:
51743e519524SHoward Hinnant            return;
51753e519524SHoward Hinnant        case 2:
51763e519524SHoward Hinnant            if (__comp(*--__last, *__first))
51773e519524SHoward Hinnant                swap(*__first, *__last);
51783e519524SHoward Hinnant            return;
51793e519524SHoward Hinnant        case 3:
51803e519524SHoward Hinnant            {
51813e519524SHoward Hinnant            _RandomAccessIterator __m = __first;
5182ce48a113SHoward Hinnant            _VSTD::__sort3<_Compare>(__first, ++__m, --__last, __comp);
51833e519524SHoward Hinnant            return;
51843e519524SHoward Hinnant            }
51853e519524SHoward Hinnant        }
51863e519524SHoward Hinnant        if (__len <= __limit)
51873e519524SHoward Hinnant        {
51883e519524SHoward Hinnant            __selection_sort<_Compare>(__first, __last, __comp);
51893e519524SHoward Hinnant            return;
51903e519524SHoward Hinnant        }
51913e519524SHoward Hinnant        // __len > __limit >= 3
51923e519524SHoward Hinnant        _RandomAccessIterator __m = __first + __len/2;
51933e519524SHoward Hinnant        _RandomAccessIterator __lm1 = __last;
5194ce48a113SHoward Hinnant        unsigned __n_swaps = _VSTD::__sort3<_Compare>(__first, __m, --__lm1, __comp);
51953e519524SHoward Hinnant        // *__m is median
51963e519524SHoward Hinnant        // partition [__first, __m) < *__m and *__m <= [__m, __last)
51973e519524SHoward Hinnant        // (this inhibits tossing elements equivalent to __m around unnecessarily)
51983e519524SHoward Hinnant        _RandomAccessIterator __i = __first;
51993e519524SHoward Hinnant        _RandomAccessIterator __j = __lm1;
52003e519524SHoward Hinnant        // j points beyond range to be tested, *__lm1 is known to be <= *__m
52013e519524SHoward Hinnant        // The search going up is known to be guarded but the search coming down isn't.
52023e519524SHoward Hinnant        // Prime the downward search with a guard.
52033e519524SHoward Hinnant        if (!__comp(*__i, *__m))  // if *__first == *__m
52043e519524SHoward Hinnant        {
52053e519524SHoward Hinnant            // *__first == *__m, *__first doesn't go in first part
52063e519524SHoward Hinnant            // manually guard downward moving __j against __i
52073e519524SHoward Hinnant            while (true)
52083e519524SHoward Hinnant            {
52093e519524SHoward Hinnant                if (__i == --__j)
52103e519524SHoward Hinnant                {
52113e519524SHoward Hinnant                    // *__first == *__m, *__m <= all other elements
52123e519524SHoward Hinnant                    // Parition instead into [__first, __i) == *__first and *__first < [__i, __last)
52133e519524SHoward Hinnant                    ++__i;  // __first + 1
52143e519524SHoward Hinnant                    __j = __last;
52153e519524SHoward Hinnant                    if (!__comp(*__first, *--__j))  // we need a guard if *__first == *(__last-1)
52163e519524SHoward Hinnant                    {
52173e519524SHoward Hinnant                        while (true)
52183e519524SHoward Hinnant                        {
52193e519524SHoward Hinnant                            if (__i == __j)
52203e519524SHoward Hinnant                                return;  // [__first, __last) all equivalent elements
52213e519524SHoward Hinnant                            if (__comp(*__first, *__i))
52223e519524SHoward Hinnant                            {
52233e519524SHoward Hinnant                                swap(*__i, *__j);
52243e519524SHoward Hinnant                                ++__n_swaps;
52253e519524SHoward Hinnant                                ++__i;
52263e519524SHoward Hinnant                                break;
52273e519524SHoward Hinnant                            }
52283e519524SHoward Hinnant                            ++__i;
52293e519524SHoward Hinnant                        }
52303e519524SHoward Hinnant                    }
52313e519524SHoward Hinnant                    // [__first, __i) == *__first and *__first < [__j, __last) and __j == __last - 1
52323e519524SHoward Hinnant                    if (__i == __j)
52333e519524SHoward Hinnant                        return;
52343e519524SHoward Hinnant                    while (true)
52353e519524SHoward Hinnant                    {
52363e519524SHoward Hinnant                        while (!__comp(*__first, *__i))
52373e519524SHoward Hinnant                            ++__i;
52383e519524SHoward Hinnant                        while (__comp(*__first, *--__j))
52393e519524SHoward Hinnant                            ;
52403e519524SHoward Hinnant                        if (__i >= __j)
52413e519524SHoward Hinnant                            break;
52423e519524SHoward Hinnant                        swap(*__i, *__j);
52433e519524SHoward Hinnant                        ++__n_swaps;
52443e519524SHoward Hinnant                        ++__i;
52453e519524SHoward Hinnant                    }
52463e519524SHoward Hinnant                    // [__first, __i) == *__first and *__first < [__i, __last)
52473e519524SHoward Hinnant                    // The first part is sorted,
52483e519524SHoward Hinnant                    if (__nth < __i)
52493e519524SHoward Hinnant                        return;
52503e519524SHoward Hinnant                    // __nth_element the secod part
52513e519524SHoward Hinnant                    // __nth_element<_Compare>(__i, __nth, __last, __comp);
52523e519524SHoward Hinnant                    __first = __i;
52533e519524SHoward Hinnant                    goto __restart;
52543e519524SHoward Hinnant                }
52553e519524SHoward Hinnant                if (__comp(*__j, *__m))
52563e519524SHoward Hinnant                {
52573e519524SHoward Hinnant                    swap(*__i, *__j);
52583e519524SHoward Hinnant                    ++__n_swaps;
52593e519524SHoward Hinnant                    break;  // found guard for downward moving __j, now use unguarded partition
52603e519524SHoward Hinnant                }
52613e519524SHoward Hinnant            }
52623e519524SHoward Hinnant        }
52633e519524SHoward Hinnant        ++__i;
52643e519524SHoward Hinnant        // j points beyond range to be tested, *__lm1 is known to be <= *__m
52653e519524SHoward Hinnant        // if not yet partitioned...
52663e519524SHoward Hinnant        if (__i < __j)
52673e519524SHoward Hinnant        {
52683e519524SHoward Hinnant            // known that *(__i - 1) < *__m
52693e519524SHoward Hinnant            while (true)
52703e519524SHoward Hinnant            {
52713e519524SHoward Hinnant                // __m still guards upward moving __i
52723e519524SHoward Hinnant                while (__comp(*__i, *__m))
52733e519524SHoward Hinnant                    ++__i;
52743e519524SHoward Hinnant                // It is now known that a guard exists for downward moving __j
52753e519524SHoward Hinnant                while (!__comp(*--__j, *__m))
52763e519524SHoward Hinnant                    ;
52773e519524SHoward Hinnant                if (__i >= __j)
52783e519524SHoward Hinnant                    break;
52793e519524SHoward Hinnant                swap(*__i, *__j);
52803e519524SHoward Hinnant                ++__n_swaps;
52813e519524SHoward Hinnant                // It is known that __m != __j
52823e519524SHoward Hinnant                // If __m just moved, follow it
52833e519524SHoward Hinnant                if (__m == __i)
52843e519524SHoward Hinnant                    __m = __j;
52853e519524SHoward Hinnant                ++__i;
52863e519524SHoward Hinnant            }
52873e519524SHoward Hinnant        }
52883e519524SHoward Hinnant        // [__first, __i) < *__m and *__m <= [__i, __last)
52893e519524SHoward Hinnant        if (__i != __m && __comp(*__m, *__i))
52903e519524SHoward Hinnant        {
52913e519524SHoward Hinnant            swap(*__i, *__m);
52923e519524SHoward Hinnant            ++__n_swaps;
52933e519524SHoward Hinnant        }
52943e519524SHoward Hinnant        // [__first, __i) < *__i and *__i <= [__i+1, __last)
52953e519524SHoward Hinnant        if (__nth == __i)
52963e519524SHoward Hinnant            return;
52973e519524SHoward Hinnant        if (__n_swaps == 0)
52983e519524SHoward Hinnant        {
52993e519524SHoward Hinnant            // We were given a perfectly partitioned sequence.  Coincidence?
53003e519524SHoward Hinnant            if (__nth < __i)
53013e519524SHoward Hinnant            {
53023e519524SHoward Hinnant                // Check for [__first, __i) already sorted
53033e519524SHoward Hinnant                __j = __m = __first;
53043e519524SHoward Hinnant                while (++__j != __i)
53053e519524SHoward Hinnant                {
53063e519524SHoward Hinnant                    if (__comp(*__j, *__m))
53073e519524SHoward Hinnant                        // not yet sorted, so sort
53083e519524SHoward Hinnant                        goto not_sorted;
53093e519524SHoward Hinnant                    __m = __j;
53103e519524SHoward Hinnant                }
53113e519524SHoward Hinnant                // [__first, __i) sorted
53123e519524SHoward Hinnant                return;
53133e519524SHoward Hinnant            }
53143e519524SHoward Hinnant            else
53153e519524SHoward Hinnant            {
53163e519524SHoward Hinnant                // Check for [__i, __last) already sorted
53173e519524SHoward Hinnant                __j = __m = __i;
53183e519524SHoward Hinnant                while (++__j != __last)
53193e519524SHoward Hinnant                {
53203e519524SHoward Hinnant                    if (__comp(*__j, *__m))
53213e519524SHoward Hinnant                        // not yet sorted, so sort
53223e519524SHoward Hinnant                        goto not_sorted;
53233e519524SHoward Hinnant                    __m = __j;
53243e519524SHoward Hinnant                }
53253e519524SHoward Hinnant                // [__i, __last) sorted
53263e519524SHoward Hinnant                return;
53273e519524SHoward Hinnant            }
53283e519524SHoward Hinnant        }
53293e519524SHoward Hinnantnot_sorted:
53303e519524SHoward Hinnant        // __nth_element on range containing __nth
53313e519524SHoward Hinnant        if (__nth < __i)
53323e519524SHoward Hinnant        {
53333e519524SHoward Hinnant            // __nth_element<_Compare>(__first, __nth, __i, __comp);
53343e519524SHoward Hinnant            __last = __i;
53353e519524SHoward Hinnant        }
53363e519524SHoward Hinnant        else
53373e519524SHoward Hinnant        {
53383e519524SHoward Hinnant            // __nth_element<_Compare>(__i+1, __nth, __last, __comp);
53393e519524SHoward Hinnant            __first = ++__i;
53403e519524SHoward Hinnant        }
53413e519524SHoward Hinnant    }
53423e519524SHoward Hinnant}
53433e519524SHoward Hinnant
53443e519524SHoward Hinnanttemplate <class _RandomAccessIterator, class _Compare>
53453e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
53463e519524SHoward Hinnantvoid
53473e519524SHoward Hinnantnth_element(_RandomAccessIterator __first, _RandomAccessIterator __nth, _RandomAccessIterator __last, _Compare __comp)
53483e519524SHoward Hinnant{
5349aa1cad15SEric Fiselier    typedef typename __comp_ref_type<_Compare>::type _Comp_ref;
53503e519524SHoward Hinnant    __nth_element<_Comp_ref>(__first, __nth, __last, __comp);
53513e519524SHoward Hinnant}
53523e519524SHoward Hinnant
53533e519524SHoward Hinnanttemplate <class _RandomAccessIterator>
53543e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
53553e519524SHoward Hinnantvoid
53563e519524SHoward Hinnantnth_element(_RandomAccessIterator __first, _RandomAccessIterator __nth, _RandomAccessIterator __last)
53573e519524SHoward Hinnant{
5358ce48a113SHoward Hinnant    _VSTD::nth_element(__first, __nth, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
53593e519524SHoward Hinnant}
53603e519524SHoward Hinnant
53613e519524SHoward Hinnant// includes
53623e519524SHoward Hinnant
53633e519524SHoward Hinnanttemplate <class _Compare, class _InputIterator1, class _InputIterator2>
53648da1a487SMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
53653e519524SHoward Hinnant__includes(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2,
53663e519524SHoward Hinnant           _Compare __comp)
53673e519524SHoward Hinnant{
53683e519524SHoward Hinnant    for (; __first2 != __last2; ++__first1)
53693e519524SHoward Hinnant    {
53703e519524SHoward Hinnant        if (__first1 == __last1 || __comp(*__first2, *__first1))
53713e519524SHoward Hinnant            return false;
53723e519524SHoward Hinnant        if (!__comp(*__first1, *__first2))
53733e519524SHoward Hinnant            ++__first2;
53743e519524SHoward Hinnant    }
53753e519524SHoward Hinnant    return true;
53763e519524SHoward Hinnant}
53773e519524SHoward Hinnant
53783e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _Compare>
53791362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
53801362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
53813e519524SHoward Hinnantbool
53823e519524SHoward Hinnantincludes(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2,
53833e519524SHoward Hinnant         _Compare __comp)
53843e519524SHoward Hinnant{
5385aa1cad15SEric Fiselier    typedef typename __comp_ref_type<_Compare>::type _Comp_ref;
53863e519524SHoward Hinnant    return __includes<_Comp_ref>(__first1, __last1, __first2, __last2, __comp);
53873e519524SHoward Hinnant}
53883e519524SHoward Hinnant
53893e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2>
53901362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
53911362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
53923e519524SHoward Hinnantbool
53933e519524SHoward Hinnantincludes(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2)
53943e519524SHoward Hinnant{
5395ce48a113SHoward Hinnant    return _VSTD::includes(__first1, __last1, __first2, __last2,
53963e519524SHoward Hinnant                          __less<typename iterator_traits<_InputIterator1>::value_type,
53973e519524SHoward Hinnant                                 typename iterator_traits<_InputIterator2>::value_type>());
53983e519524SHoward Hinnant}
53993e519524SHoward Hinnant
54003e519524SHoward Hinnant// set_union
54013e519524SHoward Hinnant
54023e519524SHoward Hinnanttemplate <class _Compare, class _InputIterator1, class _InputIterator2, class _OutputIterator>
54033e519524SHoward Hinnant_OutputIterator
54043e519524SHoward Hinnant__set_union(_InputIterator1 __first1, _InputIterator1 __last1,
54053e519524SHoward Hinnant            _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
54063e519524SHoward Hinnant{
54073e519524SHoward Hinnant    for (; __first1 != __last1; ++__result)
54083e519524SHoward Hinnant    {
54093e519524SHoward Hinnant        if (__first2 == __last2)
5410ce48a113SHoward Hinnant            return _VSTD::copy(__first1, __last1, __result);
54113e519524SHoward Hinnant        if (__comp(*__first2, *__first1))
54123e519524SHoward Hinnant        {
54133e519524SHoward Hinnant            *__result = *__first2;
54143e519524SHoward Hinnant            ++__first2;
54153e519524SHoward Hinnant        }
54163e519524SHoward Hinnant        else
54173e519524SHoward Hinnant        {
54183e519524SHoward Hinnant            if (!__comp(*__first1, *__first2))
54193e519524SHoward Hinnant                ++__first2;
542005da5b02SMarshall Clow            *__result = *__first1;
54213e519524SHoward Hinnant            ++__first1;
54223e519524SHoward Hinnant        }
54233e519524SHoward Hinnant    }
5424ce48a113SHoward Hinnant    return _VSTD::copy(__first2, __last2, __result);
54253e519524SHoward Hinnant}
54263e519524SHoward Hinnant
54273e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
54283e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
54293e519524SHoward Hinnant_OutputIterator
54303e519524SHoward Hinnantset_union(_InputIterator1 __first1, _InputIterator1 __last1,
54313e519524SHoward Hinnant          _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
54323e519524SHoward Hinnant{
5433aa1cad15SEric Fiselier    typedef typename __comp_ref_type<_Compare>::type _Comp_ref;
54343e519524SHoward Hinnant    return __set_union<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __comp);
54353e519524SHoward Hinnant}
54363e519524SHoward Hinnant
54373e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _OutputIterator>
54383e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
54393e519524SHoward Hinnant_OutputIterator
54403e519524SHoward Hinnantset_union(_InputIterator1 __first1, _InputIterator1 __last1,
54413e519524SHoward Hinnant          _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result)
54423e519524SHoward Hinnant{
5443ce48a113SHoward Hinnant    return _VSTD::set_union(__first1, __last1, __first2, __last2, __result,
54443e519524SHoward Hinnant                          __less<typename iterator_traits<_InputIterator1>::value_type,
54453e519524SHoward Hinnant                                 typename iterator_traits<_InputIterator2>::value_type>());
54463e519524SHoward Hinnant}
54473e519524SHoward Hinnant
54483e519524SHoward Hinnant// set_intersection
54493e519524SHoward Hinnant
54503e519524SHoward Hinnanttemplate <class _Compare, class _InputIterator1, class _InputIterator2, class _OutputIterator>
54518da1a487SMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 _OutputIterator
54523e519524SHoward Hinnant__set_intersection(_InputIterator1 __first1, _InputIterator1 __last1,
54533e519524SHoward Hinnant                   _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
54543e519524SHoward Hinnant{
54553e519524SHoward Hinnant    while (__first1 != __last1 && __first2 != __last2)
54563e519524SHoward Hinnant    {
54573e519524SHoward Hinnant        if (__comp(*__first1, *__first2))
54583e519524SHoward Hinnant            ++__first1;
54593e519524SHoward Hinnant        else
54603e519524SHoward Hinnant        {
54613e519524SHoward Hinnant            if (!__comp(*__first2, *__first1))
54623e519524SHoward Hinnant            {
54633e519524SHoward Hinnant                *__result = *__first1;
54643e519524SHoward Hinnant                ++__result;
54653e519524SHoward Hinnant                ++__first1;
54663e519524SHoward Hinnant            }
54673e519524SHoward Hinnant            ++__first2;
54683e519524SHoward Hinnant        }
54693e519524SHoward Hinnant    }
54703e519524SHoward Hinnant    return __result;
54713e519524SHoward Hinnant}
54723e519524SHoward Hinnant
54733e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
54748da1a487SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
54753e519524SHoward Hinnant_OutputIterator
54763e519524SHoward Hinnantset_intersection(_InputIterator1 __first1, _InputIterator1 __last1,
54773e519524SHoward Hinnant                 _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
54783e519524SHoward Hinnant{
5479aa1cad15SEric Fiselier    typedef typename __comp_ref_type<_Compare>::type _Comp_ref;
54803e519524SHoward Hinnant    return __set_intersection<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __comp);
54813e519524SHoward Hinnant}
54823e519524SHoward Hinnant
54833e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _OutputIterator>
54848da1a487SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
54853e519524SHoward Hinnant_OutputIterator
54863e519524SHoward Hinnantset_intersection(_InputIterator1 __first1, _InputIterator1 __last1,
54873e519524SHoward Hinnant                 _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result)
54883e519524SHoward Hinnant{
5489ce48a113SHoward Hinnant    return _VSTD::set_intersection(__first1, __last1, __first2, __last2, __result,
54903e519524SHoward Hinnant                                  __less<typename iterator_traits<_InputIterator1>::value_type,
54913e519524SHoward Hinnant                                         typename iterator_traits<_InputIterator2>::value_type>());
54923e519524SHoward Hinnant}
54933e519524SHoward Hinnant
54943e519524SHoward Hinnant// set_difference
54953e519524SHoward Hinnant
54963e519524SHoward Hinnanttemplate <class _Compare, class _InputIterator1, class _InputIterator2, class _OutputIterator>
54973e519524SHoward Hinnant_OutputIterator
54983e519524SHoward Hinnant__set_difference(_InputIterator1 __first1, _InputIterator1 __last1,
54993e519524SHoward Hinnant                 _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
55003e519524SHoward Hinnant{
55013e519524SHoward Hinnant    while (__first1 != __last1)
55023e519524SHoward Hinnant    {
55033e519524SHoward Hinnant        if (__first2 == __last2)
5504ce48a113SHoward Hinnant            return _VSTD::copy(__first1, __last1, __result);
55053e519524SHoward Hinnant        if (__comp(*__first1, *__first2))
55063e519524SHoward Hinnant        {
55073e519524SHoward Hinnant            *__result = *__first1;
55083e519524SHoward Hinnant            ++__result;
55093e519524SHoward Hinnant            ++__first1;
55103e519524SHoward Hinnant        }
55113e519524SHoward Hinnant        else
55123e519524SHoward Hinnant        {
55133e519524SHoward Hinnant            if (!__comp(*__first2, *__first1))
55143e519524SHoward Hinnant                ++__first1;
55153e519524SHoward Hinnant            ++__first2;
55163e519524SHoward Hinnant        }
55173e519524SHoward Hinnant    }
55183e519524SHoward Hinnant    return __result;
55193e519524SHoward Hinnant}
55203e519524SHoward Hinnant
55213e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
55223e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
55233e519524SHoward Hinnant_OutputIterator
55243e519524SHoward Hinnantset_difference(_InputIterator1 __first1, _InputIterator1 __last1,
55253e519524SHoward Hinnant               _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
55263e519524SHoward Hinnant{
5527aa1cad15SEric Fiselier    typedef typename __comp_ref_type<_Compare>::type _Comp_ref;
55283e519524SHoward Hinnant    return __set_difference<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __comp);
55293e519524SHoward Hinnant}
55303e519524SHoward Hinnant
55313e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _OutputIterator>
55323e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
55333e519524SHoward Hinnant_OutputIterator
55343e519524SHoward Hinnantset_difference(_InputIterator1 __first1, _InputIterator1 __last1,
55353e519524SHoward Hinnant               _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result)
55363e519524SHoward Hinnant{
5537ce48a113SHoward Hinnant    return _VSTD::set_difference(__first1, __last1, __first2, __last2, __result,
55383e519524SHoward Hinnant                                __less<typename iterator_traits<_InputIterator1>::value_type,
55393e519524SHoward Hinnant                                       typename iterator_traits<_InputIterator2>::value_type>());
55403e519524SHoward Hinnant}
55413e519524SHoward Hinnant
55423e519524SHoward Hinnant// set_symmetric_difference
55433e519524SHoward Hinnant
55443e519524SHoward Hinnanttemplate <class _Compare, class _InputIterator1, class _InputIterator2, class _OutputIterator>
55453e519524SHoward Hinnant_OutputIterator
55463e519524SHoward Hinnant__set_symmetric_difference(_InputIterator1 __first1, _InputIterator1 __last1,
55473e519524SHoward Hinnant                           _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
55483e519524SHoward Hinnant{
55493e519524SHoward Hinnant    while (__first1 != __last1)
55503e519524SHoward Hinnant    {
55513e519524SHoward Hinnant        if (__first2 == __last2)
5552ce48a113SHoward Hinnant            return _VSTD::copy(__first1, __last1, __result);
55533e519524SHoward Hinnant        if (__comp(*__first1, *__first2))
55543e519524SHoward Hinnant        {
55553e519524SHoward Hinnant            *__result = *__first1;
55563e519524SHoward Hinnant            ++__result;
55573e519524SHoward Hinnant            ++__first1;
55583e519524SHoward Hinnant        }
55593e519524SHoward Hinnant        else
55603e519524SHoward Hinnant        {
55613e519524SHoward Hinnant            if (__comp(*__first2, *__first1))
55623e519524SHoward Hinnant            {
55633e519524SHoward Hinnant                *__result = *__first2;
55643e519524SHoward Hinnant                ++__result;
55653e519524SHoward Hinnant            }
55663e519524SHoward Hinnant            else
55673e519524SHoward Hinnant                ++__first1;
55683e519524SHoward Hinnant            ++__first2;
55693e519524SHoward Hinnant        }
55703e519524SHoward Hinnant    }
5571ce48a113SHoward Hinnant    return _VSTD::copy(__first2, __last2, __result);
55723e519524SHoward Hinnant}
55733e519524SHoward Hinnant
55743e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
55753e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
55763e519524SHoward Hinnant_OutputIterator
55773e519524SHoward Hinnantset_symmetric_difference(_InputIterator1 __first1, _InputIterator1 __last1,
55783e519524SHoward Hinnant                         _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
55793e519524SHoward Hinnant{
5580aa1cad15SEric Fiselier    typedef typename __comp_ref_type<_Compare>::type _Comp_ref;
55813e519524SHoward Hinnant    return __set_symmetric_difference<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __comp);
55823e519524SHoward Hinnant}
55833e519524SHoward Hinnant
55843e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _OutputIterator>
55853e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
55863e519524SHoward Hinnant_OutputIterator
55873e519524SHoward Hinnantset_symmetric_difference(_InputIterator1 __first1, _InputIterator1 __last1,
55883e519524SHoward Hinnant                         _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result)
55893e519524SHoward Hinnant{
5590ce48a113SHoward Hinnant    return _VSTD::set_symmetric_difference(__first1, __last1, __first2, __last2, __result,
55913e519524SHoward Hinnant                                          __less<typename iterator_traits<_InputIterator1>::value_type,
55923e519524SHoward Hinnant                                                 typename iterator_traits<_InputIterator2>::value_type>());
55933e519524SHoward Hinnant}
55943e519524SHoward Hinnant
55953e519524SHoward Hinnant// lexicographical_compare
55963e519524SHoward Hinnant
55973e519524SHoward Hinnanttemplate <class _Compare, class _InputIterator1, class _InputIterator2>
55981b9a4ffdSMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
55993e519524SHoward Hinnant__lexicographical_compare(_InputIterator1 __first1, _InputIterator1 __last1,
56003e519524SHoward Hinnant                          _InputIterator2 __first2, _InputIterator2 __last2, _Compare __comp)
56013e519524SHoward Hinnant{
5602910285b2SEric Fiselier    for (; __first2 != __last2; ++__first1, (void) ++__first2)
56033e519524SHoward Hinnant    {
56043e519524SHoward Hinnant        if (__first1 == __last1 || __comp(*__first1, *__first2))
56053e519524SHoward Hinnant            return true;
56063e519524SHoward Hinnant        if (__comp(*__first2, *__first1))
56073e519524SHoward Hinnant            return false;
56083e519524SHoward Hinnant    }
56093e519524SHoward Hinnant    return false;
56103e519524SHoward Hinnant}
56113e519524SHoward Hinnant
56123e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _Compare>
56131362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
56141362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
56153e519524SHoward Hinnantbool
56163e519524SHoward Hinnantlexicographical_compare(_InputIterator1 __first1, _InputIterator1 __last1,
56173e519524SHoward Hinnant                        _InputIterator2 __first2, _InputIterator2 __last2, _Compare __comp)
56183e519524SHoward Hinnant{
5619aa1cad15SEric Fiselier    typedef typename __comp_ref_type<_Compare>::type _Comp_ref;
56203e519524SHoward Hinnant    return __lexicographical_compare<_Comp_ref>(__first1, __last1, __first2, __last2, __comp);
56213e519524SHoward Hinnant}
56223e519524SHoward Hinnant
56233e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2>
56241362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
56251362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
56263e519524SHoward Hinnantbool
56273e519524SHoward Hinnantlexicographical_compare(_InputIterator1 __first1, _InputIterator1 __last1,
56283e519524SHoward Hinnant                        _InputIterator2 __first2, _InputIterator2 __last2)
56293e519524SHoward Hinnant{
5630ce48a113SHoward Hinnant    return _VSTD::lexicographical_compare(__first1, __last1, __first2, __last2,
56313e519524SHoward Hinnant                                         __less<typename iterator_traits<_InputIterator1>::value_type,
56323e519524SHoward Hinnant                                                typename iterator_traits<_InputIterator2>::value_type>());
56333e519524SHoward Hinnant}
56343e519524SHoward Hinnant
56353e519524SHoward Hinnant// next_permutation
56363e519524SHoward Hinnant
56373e519524SHoward Hinnanttemplate <class _Compare, class _BidirectionalIterator>
56383e519524SHoward Hinnantbool
56393e519524SHoward Hinnant__next_permutation(_BidirectionalIterator __first, _BidirectionalIterator __last, _Compare __comp)
56403e519524SHoward Hinnant{
56413e519524SHoward Hinnant    _BidirectionalIterator __i = __last;
56423e519524SHoward Hinnant    if (__first == __last || __first == --__i)
56433e519524SHoward Hinnant        return false;
56443e519524SHoward Hinnant    while (true)
56453e519524SHoward Hinnant    {
56463e519524SHoward Hinnant        _BidirectionalIterator __ip1 = __i;
56473e519524SHoward Hinnant        if (__comp(*--__i, *__ip1))
56483e519524SHoward Hinnant        {
56493e519524SHoward Hinnant            _BidirectionalIterator __j = __last;
56503e519524SHoward Hinnant            while (!__comp(*__i, *--__j))
56513e519524SHoward Hinnant                ;
56523e519524SHoward Hinnant            swap(*__i, *__j);
5653ce48a113SHoward Hinnant            _VSTD::reverse(__ip1, __last);
56543e519524SHoward Hinnant            return true;
56553e519524SHoward Hinnant        }
56563e519524SHoward Hinnant        if (__i == __first)
56573e519524SHoward Hinnant        {
5658ce48a113SHoward Hinnant            _VSTD::reverse(__first, __last);
56593e519524SHoward Hinnant            return false;
56603e519524SHoward Hinnant        }
56613e519524SHoward Hinnant    }
56623e519524SHoward Hinnant}
56633e519524SHoward Hinnant
56643e519524SHoward Hinnanttemplate <class _BidirectionalIterator, class _Compare>
56653e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
56663e519524SHoward Hinnantbool
56673e519524SHoward Hinnantnext_permutation(_BidirectionalIterator __first, _BidirectionalIterator __last, _Compare __comp)
56683e519524SHoward Hinnant{
5669aa1cad15SEric Fiselier    typedef typename __comp_ref_type<_Compare>::type _Comp_ref;
56703e519524SHoward Hinnant    return __next_permutation<_Comp_ref>(__first, __last, __comp);
56713e519524SHoward Hinnant}
56723e519524SHoward Hinnant
56733e519524SHoward Hinnanttemplate <class _BidirectionalIterator>
56743e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
56753e519524SHoward Hinnantbool
56763e519524SHoward Hinnantnext_permutation(_BidirectionalIterator __first, _BidirectionalIterator __last)
56773e519524SHoward Hinnant{
5678ce48a113SHoward Hinnant    return _VSTD::next_permutation(__first, __last,
56793e519524SHoward Hinnant                                  __less<typename iterator_traits<_BidirectionalIterator>::value_type>());
56803e519524SHoward Hinnant}
56813e519524SHoward Hinnant
56823e519524SHoward Hinnant// prev_permutation
56833e519524SHoward Hinnant
56843e519524SHoward Hinnanttemplate <class _Compare, class _BidirectionalIterator>
56853e519524SHoward Hinnantbool
56863e519524SHoward Hinnant__prev_permutation(_BidirectionalIterator __first, _BidirectionalIterator __last, _Compare __comp)
56873e519524SHoward Hinnant{
56883e519524SHoward Hinnant    _BidirectionalIterator __i = __last;
56893e519524SHoward Hinnant    if (__first == __last || __first == --__i)
56903e519524SHoward Hinnant        return false;
56913e519524SHoward Hinnant    while (true)
56923e519524SHoward Hinnant    {
56933e519524SHoward Hinnant        _BidirectionalIterator __ip1 = __i;
56943e519524SHoward Hinnant        if (__comp(*__ip1, *--__i))
56953e519524SHoward Hinnant        {
56963e519524SHoward Hinnant            _BidirectionalIterator __j = __last;
56973e519524SHoward Hinnant            while (!__comp(*--__j, *__i))
56983e519524SHoward Hinnant                ;
56993e519524SHoward Hinnant            swap(*__i, *__j);
5700ce48a113SHoward Hinnant            _VSTD::reverse(__ip1, __last);
57013e519524SHoward Hinnant            return true;
57023e519524SHoward Hinnant        }
57033e519524SHoward Hinnant        if (__i == __first)
57043e519524SHoward Hinnant        {
5705ce48a113SHoward Hinnant            _VSTD::reverse(__first, __last);
57063e519524SHoward Hinnant            return false;
57073e519524SHoward Hinnant        }
57083e519524SHoward Hinnant    }
57093e519524SHoward Hinnant}
57103e519524SHoward Hinnant
57113e519524SHoward Hinnanttemplate <class _BidirectionalIterator, class _Compare>
57123e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
57133e519524SHoward Hinnantbool
57143e519524SHoward Hinnantprev_permutation(_BidirectionalIterator __first, _BidirectionalIterator __last, _Compare __comp)
57153e519524SHoward Hinnant{
5716aa1cad15SEric Fiselier    typedef typename __comp_ref_type<_Compare>::type _Comp_ref;
57173e519524SHoward Hinnant    return __prev_permutation<_Comp_ref>(__first, __last, __comp);
57183e519524SHoward Hinnant}
57193e519524SHoward Hinnant
57203e519524SHoward Hinnanttemplate <class _BidirectionalIterator>
57213e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
57223e519524SHoward Hinnantbool
57233e519524SHoward Hinnantprev_permutation(_BidirectionalIterator __first, _BidirectionalIterator __last)
57243e519524SHoward Hinnant{
5725ce48a113SHoward Hinnant    return _VSTD::prev_permutation(__first, __last,
57263e519524SHoward Hinnant                                  __less<typename iterator_traits<_BidirectionalIterator>::value_type>());
57273e519524SHoward Hinnant}
57283e519524SHoward Hinnant
57293e519524SHoward Hinnant_LIBCPP_END_NAMESPACE_STD
57303e519524SHoward Hinnant
5731a016efb1SEric Fiselier_LIBCPP_POP_MACROS
5732a016efb1SEric Fiselier
57330a06eb91SLouis Dionne#if defined(_LIBCPP_HAS_PARALLEL_ALGORITHMS) && _LIBCPP_STD_VER >= 17
573495689243SLouis Dionne#   include <__pstl_algorithm>
57350a06eb91SLouis Dionne#endif
57360a06eb91SLouis Dionne
57373e519524SHoward Hinnant#endif  // _LIBCPP_ALGORITHM
5738