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>
1703e519524SHoward Hinnant    OutputIterator
1713e519524SHoward Hinnant    copy(InputIterator first, InputIterator last, OutputIterator result);
1723e519524SHoward Hinnant
1733e519524SHoward Hinnanttemplate<class InputIterator, class OutputIterator, class Predicate>
1743e519524SHoward Hinnant    OutputIterator
1753e519524SHoward Hinnant    copy_if(InputIterator first, InputIterator last,
1763e519524SHoward Hinnant            OutputIterator result, Predicate pred);
1773e519524SHoward Hinnant
1783e519524SHoward Hinnanttemplate<class InputIterator, class Size, class OutputIterator>
1793e519524SHoward Hinnant    OutputIterator
1803e519524SHoward Hinnant    copy_n(InputIterator first, Size n, OutputIterator result);
1813e519524SHoward Hinnant
1823e519524SHoward Hinnanttemplate <class BidirectionalIterator1, class BidirectionalIterator2>
1833e519524SHoward Hinnant    BidirectionalIterator2
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{
7833e519524SHoward Hinnant    _Compare __comp_;
7843e519524SHoward Hinnant    __debug_less(_Compare& __c) : __comp_(__c) {}
785331d2159SEric Fiselier
7863e519524SHoward Hinnant    template <class _Tp, class _Up>
7876e4ec602SEric Fiselier    bool operator()(_Tp& __x,  _Up& __y)
7883e519524SHoward Hinnant    {
7893e519524SHoward Hinnant        bool __r = __comp_(__x, __y);
7903e519524SHoward Hinnant        if (__r)
791331d2159SEric Fiselier            __do_compare_assert(0, __y, __x);
7923e519524SHoward Hinnant        return __r;
7933e519524SHoward Hinnant    }
794331d2159SEric Fiselier
795331d2159SEric Fiselier    template <class _LHS, class _RHS>
796331d2159SEric Fiselier    inline _LIBCPP_INLINE_VISIBILITY
797331d2159SEric Fiselier    decltype((void)_VSTD::declval<_Compare&>()(
7986e4ec602SEric Fiselier        _VSTD::declval<_LHS &>(), _VSTD::declval<_RHS &>()))
7996e4ec602SEric Fiselier    __do_compare_assert(int, _LHS & __l, _RHS & __r) {
800331d2159SEric Fiselier        _LIBCPP_ASSERT(!__comp_(__l, __r),
801331d2159SEric Fiselier            "Comparator does not induce a strict weak ordering");
802331d2159SEric Fiselier    }
803331d2159SEric Fiselier
804331d2159SEric Fiselier    template <class _LHS, class _RHS>
805331d2159SEric Fiselier    inline _LIBCPP_INLINE_VISIBILITY
8066e4ec602SEric Fiselier    void __do_compare_assert(long, _LHS &, _RHS &) {}
8073e519524SHoward Hinnant};
8083e519524SHoward Hinnant
809145afa17SHoward Hinnant#endif // _LIBCPP_DEBUG
8103e519524SHoward Hinnant
8113e519524SHoward Hinnant// all_of
8123e519524SHoward Hinnant
8133e519524SHoward Hinnanttemplate <class _InputIterator, class _Predicate>
814*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
815*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
8163e519524SHoward Hinnantbool
8173e519524SHoward Hinnantall_of(_InputIterator __first, _InputIterator __last, _Predicate __pred)
8183e519524SHoward Hinnant{
8193e519524SHoward Hinnant    for (; __first != __last; ++__first)
8203e519524SHoward Hinnant        if (!__pred(*__first))
8213e519524SHoward Hinnant            return false;
8223e519524SHoward Hinnant    return true;
8233e519524SHoward Hinnant}
8243e519524SHoward Hinnant
8253e519524SHoward Hinnant// any_of
8263e519524SHoward Hinnant
8273e519524SHoward Hinnanttemplate <class _InputIterator, class _Predicate>
828*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
829*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
8303e519524SHoward Hinnantbool
8313e519524SHoward Hinnantany_of(_InputIterator __first, _InputIterator __last, _Predicate __pred)
8323e519524SHoward Hinnant{
8333e519524SHoward Hinnant    for (; __first != __last; ++__first)
8343e519524SHoward Hinnant        if (__pred(*__first))
8353e519524SHoward Hinnant            return true;
8363e519524SHoward Hinnant    return false;
8373e519524SHoward Hinnant}
8383e519524SHoward Hinnant
8393e519524SHoward Hinnant// none_of
8403e519524SHoward Hinnant
8413e519524SHoward Hinnanttemplate <class _InputIterator, class _Predicate>
842*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
843*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
8443e519524SHoward Hinnantbool
8453e519524SHoward Hinnantnone_of(_InputIterator __first, _InputIterator __last, _Predicate __pred)
8463e519524SHoward Hinnant{
8473e519524SHoward Hinnant    for (; __first != __last; ++__first)
8483e519524SHoward Hinnant        if (__pred(*__first))
8493e519524SHoward Hinnant            return false;
8503e519524SHoward Hinnant    return true;
8513e519524SHoward Hinnant}
8523e519524SHoward Hinnant
8533e519524SHoward Hinnant// for_each
8543e519524SHoward Hinnant
8553e519524SHoward Hinnanttemplate <class _InputIterator, class _Function>
8561b9a4ffdSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
8573e519524SHoward Hinnant_Function
8583e519524SHoward Hinnantfor_each(_InputIterator __first, _InputIterator __last, _Function __f)
8593e519524SHoward Hinnant{
8603e519524SHoward Hinnant    for (; __first != __last; ++__first)
8613e519524SHoward Hinnant        __f(*__first);
8621c7fe126SMarshall Clow    return __f;
8633e519524SHoward Hinnant}
8643e519524SHoward Hinnant
8651d02996dSMarshall Clow#if _LIBCPP_STD_VER > 14
866d5c65ffaSMarshall Clow// for_each_n
867d5c65ffaSMarshall Clow
868d5c65ffaSMarshall Clowtemplate <class _InputIterator, class _Size, class _Function>
8691b9a4ffdSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
870d5c65ffaSMarshall Clow_InputIterator
871d5c65ffaSMarshall Clowfor_each_n(_InputIterator __first, _Size __orig_n, _Function __f)
872d5c65ffaSMarshall Clow{
873d5c65ffaSMarshall Clow    typedef decltype(__convert_to_integral(__orig_n)) _IntegralSize;
874d5c65ffaSMarshall Clow    _IntegralSize __n = __orig_n;
875d5c65ffaSMarshall Clow    while (__n > 0)
876d5c65ffaSMarshall Clow    {
877d5c65ffaSMarshall Clow         __f(*__first);
878d5c65ffaSMarshall Clow         ++__first;
879d5c65ffaSMarshall Clow         --__n;
880d5c65ffaSMarshall Clow    }
881d5c65ffaSMarshall Clow    return __first;
882d5c65ffaSMarshall Clow}
8831d02996dSMarshall Clow#endif
884d5c65ffaSMarshall Clow
8853e519524SHoward Hinnant// find
8863e519524SHoward Hinnant
8873e519524SHoward Hinnanttemplate <class _InputIterator, class _Tp>
888*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
889*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
8903e519524SHoward Hinnant_InputIterator
891e4383379SHoward Hinnantfind(_InputIterator __first, _InputIterator __last, const _Tp& __value_)
8923e519524SHoward Hinnant{
8933e519524SHoward Hinnant    for (; __first != __last; ++__first)
894e4383379SHoward Hinnant        if (*__first == __value_)
8953e519524SHoward Hinnant            break;
8963e519524SHoward Hinnant    return __first;
8973e519524SHoward Hinnant}
8983e519524SHoward Hinnant
8993e519524SHoward Hinnant// find_if
9003e519524SHoward Hinnant
9013e519524SHoward Hinnanttemplate <class _InputIterator, class _Predicate>
902*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
903*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
9043e519524SHoward Hinnant_InputIterator
9053e519524SHoward Hinnantfind_if(_InputIterator __first, _InputIterator __last, _Predicate __pred)
9063e519524SHoward Hinnant{
9073e519524SHoward Hinnant    for (; __first != __last; ++__first)
9083e519524SHoward Hinnant        if (__pred(*__first))
9093e519524SHoward Hinnant            break;
9103e519524SHoward Hinnant    return __first;
9113e519524SHoward Hinnant}
9123e519524SHoward Hinnant
9133e519524SHoward Hinnant// find_if_not
9143e519524SHoward Hinnant
9153e519524SHoward Hinnanttemplate<class _InputIterator, class _Predicate>
916*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
917*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
9183e519524SHoward Hinnant_InputIterator
9193e519524SHoward Hinnantfind_if_not(_InputIterator __first, _InputIterator __last, _Predicate __pred)
9203e519524SHoward Hinnant{
9213e519524SHoward Hinnant    for (; __first != __last; ++__first)
9223e519524SHoward Hinnant        if (!__pred(*__first))
9233e519524SHoward Hinnant            break;
9243e519524SHoward Hinnant    return __first;
9253e519524SHoward Hinnant}
9263e519524SHoward Hinnant
9273e519524SHoward Hinnant// find_end
9283e519524SHoward Hinnant
9293e519524SHoward Hinnanttemplate <class _BinaryPredicate, class _ForwardIterator1, class _ForwardIterator2>
9308694428eSMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator1
9313e519524SHoward Hinnant__find_end(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
9323e519524SHoward Hinnant           _ForwardIterator2 __first2, _ForwardIterator2 __last2, _BinaryPredicate __pred,
9333e519524SHoward Hinnant           forward_iterator_tag, forward_iterator_tag)
9343e519524SHoward Hinnant{
9353e519524SHoward Hinnant    // modeled after search algorithm
9363e519524SHoward Hinnant    _ForwardIterator1 __r = __last1;  // __last1 is the "default" answer
9373e519524SHoward Hinnant    if (__first2 == __last2)
9383e519524SHoward Hinnant        return __r;
9393e519524SHoward Hinnant    while (true)
9403e519524SHoward Hinnant    {
9413e519524SHoward Hinnant        while (true)
9423e519524SHoward Hinnant        {
9433e519524SHoward Hinnant            if (__first1 == __last1)         // if source exhausted return last correct answer
9443e519524SHoward Hinnant                return __r;                  //    (or __last1 if never found)
9453e519524SHoward Hinnant            if (__pred(*__first1, *__first2))
9463e519524SHoward Hinnant                break;
9473e519524SHoward Hinnant            ++__first1;
9483e519524SHoward Hinnant        }
9493e519524SHoward Hinnant        // *__first1 matches *__first2, now match elements after here
9503e519524SHoward Hinnant        _ForwardIterator1 __m1 = __first1;
9513e519524SHoward Hinnant        _ForwardIterator2 __m2 = __first2;
9523e519524SHoward Hinnant        while (true)
9533e519524SHoward Hinnant        {
9543e519524SHoward Hinnant            if (++__m2 == __last2)
9553e519524SHoward Hinnant            {                         // Pattern exhaused, record answer and search for another one
9563e519524SHoward Hinnant                __r = __first1;
9573e519524SHoward Hinnant                ++__first1;
9583e519524SHoward Hinnant                break;
9593e519524SHoward Hinnant            }
9603e519524SHoward Hinnant            if (++__m1 == __last1)     // Source exhausted, return last answer
9613e519524SHoward Hinnant                return __r;
9623e519524SHoward Hinnant            if (!__pred(*__m1, *__m2))  // mismatch, restart with a new __first
9633e519524SHoward Hinnant            {
9643e519524SHoward Hinnant                ++__first1;
9653e519524SHoward Hinnant                break;
9663e519524SHoward Hinnant            }  // else there is a match, check next elements
9673e519524SHoward Hinnant        }
9683e519524SHoward Hinnant    }
9693e519524SHoward Hinnant}
9703e519524SHoward Hinnant
9713e519524SHoward Hinnanttemplate <class _BinaryPredicate, class _BidirectionalIterator1, class _BidirectionalIterator2>
9728694428eSMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 _BidirectionalIterator1
9733e519524SHoward Hinnant__find_end(_BidirectionalIterator1 __first1, _BidirectionalIterator1 __last1,
9743e519524SHoward Hinnant           _BidirectionalIterator2 __first2, _BidirectionalIterator2 __last2, _BinaryPredicate __pred,
9753e519524SHoward Hinnant           bidirectional_iterator_tag, bidirectional_iterator_tag)
9763e519524SHoward Hinnant{
9773e519524SHoward Hinnant    // modeled after search algorithm (in reverse)
9783e519524SHoward Hinnant    if (__first2 == __last2)
9793e519524SHoward Hinnant        return __last1;  // Everything matches an empty sequence
9803e519524SHoward Hinnant    _BidirectionalIterator1 __l1 = __last1;
9813e519524SHoward Hinnant    _BidirectionalIterator2 __l2 = __last2;
9823e519524SHoward Hinnant    --__l2;
9833e519524SHoward Hinnant    while (true)
9843e519524SHoward Hinnant    {
9853e519524SHoward Hinnant        // Find last element in sequence 1 that matchs *(__last2-1), with a mininum of loop checks
9863e519524SHoward Hinnant        while (true)
9873e519524SHoward Hinnant        {
9883e519524SHoward Hinnant            if (__first1 == __l1)  // return __last1 if no element matches *__first2
9893e519524SHoward Hinnant                return __last1;
9903e519524SHoward Hinnant            if (__pred(*--__l1, *__l2))
9913e519524SHoward Hinnant                break;
9923e519524SHoward Hinnant        }
9933e519524SHoward Hinnant        // *__l1 matches *__l2, now match elements before here
9943e519524SHoward Hinnant        _BidirectionalIterator1 __m1 = __l1;
9953e519524SHoward Hinnant        _BidirectionalIterator2 __m2 = __l2;
9963e519524SHoward Hinnant        while (true)
9973e519524SHoward Hinnant        {
9983e519524SHoward Hinnant            if (__m2 == __first2)  // If pattern exhausted, __m1 is the answer (works for 1 element pattern)
9993e519524SHoward Hinnant                return __m1;
10003e519524SHoward Hinnant            if (__m1 == __first1)  // Otherwise if source exhaused, pattern not found
10013e519524SHoward Hinnant                return __last1;
10023e519524SHoward Hinnant            if (!__pred(*--__m1, *--__m2))  // if there is a mismatch, restart with a new __l1
10033e519524SHoward Hinnant            {
10043e519524SHoward Hinnant                break;
10053e519524SHoward Hinnant            }  // else there is a match, check next elements
10063e519524SHoward Hinnant        }
10073e519524SHoward Hinnant    }
10083e519524SHoward Hinnant}
10093e519524SHoward Hinnant
10103e519524SHoward Hinnanttemplate <class _BinaryPredicate, class _RandomAccessIterator1, class _RandomAccessIterator2>
10119b0af34dSMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX11 _RandomAccessIterator1
10123e519524SHoward Hinnant__find_end(_RandomAccessIterator1 __first1, _RandomAccessIterator1 __last1,
10133e519524SHoward Hinnant           _RandomAccessIterator2 __first2, _RandomAccessIterator2 __last2, _BinaryPredicate __pred,
10143e519524SHoward Hinnant           random_access_iterator_tag, random_access_iterator_tag)
10153e519524SHoward Hinnant{
10163e519524SHoward Hinnant    // Take advantage of knowing source and pattern lengths.  Stop short when source is smaller than pattern
10173e519524SHoward Hinnant    typename iterator_traits<_RandomAccessIterator2>::difference_type __len2 = __last2 - __first2;
10183e519524SHoward Hinnant    if (__len2 == 0)
10193e519524SHoward Hinnant        return __last1;
10203e519524SHoward Hinnant    typename iterator_traits<_RandomAccessIterator1>::difference_type __len1 = __last1 - __first1;
10213e519524SHoward Hinnant    if (__len1 < __len2)
10223e519524SHoward Hinnant        return __last1;
10233e519524SHoward Hinnant    const _RandomAccessIterator1 __s = __first1 + (__len2 - 1);  // End of pattern match can't go before here
10243e519524SHoward Hinnant    _RandomAccessIterator1 __l1 = __last1;
10253e519524SHoward Hinnant    _RandomAccessIterator2 __l2 = __last2;
10263e519524SHoward Hinnant    --__l2;
10273e519524SHoward Hinnant    while (true)
10283e519524SHoward Hinnant    {
10293e519524SHoward Hinnant        while (true)
10303e519524SHoward Hinnant        {
10313e519524SHoward Hinnant            if (__s == __l1)
10323e519524SHoward Hinnant                return __last1;
10333e519524SHoward Hinnant            if (__pred(*--__l1, *__l2))
10343e519524SHoward Hinnant                break;
10353e519524SHoward Hinnant        }
10363e519524SHoward Hinnant        _RandomAccessIterator1 __m1 = __l1;
10373e519524SHoward Hinnant        _RandomAccessIterator2 __m2 = __l2;
10383e519524SHoward Hinnant        while (true)
10393e519524SHoward Hinnant        {
10403e519524SHoward Hinnant            if (__m2 == __first2)
10413e519524SHoward Hinnant                return __m1;
10423e519524SHoward Hinnant                                 // no need to check range on __m1 because __s guarantees we have enough source
10433e519524SHoward Hinnant            if (!__pred(*--__m1, *--__m2))
10443e519524SHoward Hinnant            {
10453e519524SHoward Hinnant                break;
10463e519524SHoward Hinnant            }
10473e519524SHoward Hinnant        }
10483e519524SHoward Hinnant    }
10493e519524SHoward Hinnant}
10503e519524SHoward Hinnant
10513e519524SHoward Hinnanttemplate <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
1052*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
1053*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
10543e519524SHoward Hinnant_ForwardIterator1
10553e519524SHoward Hinnantfind_end(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
10563e519524SHoward Hinnant         _ForwardIterator2 __first2, _ForwardIterator2 __last2, _BinaryPredicate __pred)
10573e519524SHoward Hinnant{
1058ce48a113SHoward Hinnant    return _VSTD::__find_end<typename add_lvalue_reference<_BinaryPredicate>::type>
10593e519524SHoward Hinnant                         (__first1, __last1, __first2, __last2, __pred,
10603e519524SHoward Hinnant                          typename iterator_traits<_ForwardIterator1>::iterator_category(),
10613e519524SHoward Hinnant                          typename iterator_traits<_ForwardIterator2>::iterator_category());
10623e519524SHoward Hinnant}
10633e519524SHoward Hinnant
10643e519524SHoward Hinnanttemplate <class _ForwardIterator1, class _ForwardIterator2>
1065*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
1066*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
10673e519524SHoward Hinnant_ForwardIterator1
10683e519524SHoward Hinnantfind_end(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
10693e519524SHoward Hinnant         _ForwardIterator2 __first2, _ForwardIterator2 __last2)
10703e519524SHoward Hinnant{
10713e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator1>::value_type __v1;
10723e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator2>::value_type __v2;
1073ce48a113SHoward Hinnant    return _VSTD::find_end(__first1, __last1, __first2, __last2, __equal_to<__v1, __v2>());
10743e519524SHoward Hinnant}
10753e519524SHoward Hinnant
10763e519524SHoward Hinnant// find_first_of
10773e519524SHoward Hinnant
10783e519524SHoward Hinnanttemplate <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
10799b0af34dSMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX11 _ForwardIterator1
10809b0af34dSMarshall Clow__find_first_of_ce(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
10813e519524SHoward Hinnant              _ForwardIterator2 __first2, _ForwardIterator2 __last2, _BinaryPredicate __pred)
10823e519524SHoward Hinnant{
10833e519524SHoward Hinnant    for (; __first1 != __last1; ++__first1)
10843e519524SHoward Hinnant        for (_ForwardIterator2 __j = __first2; __j != __last2; ++__j)
10853e519524SHoward Hinnant            if (__pred(*__first1, *__j))
10863e519524SHoward Hinnant                return __first1;
10873e519524SHoward Hinnant    return __last1;
10883e519524SHoward Hinnant}
10893e519524SHoward Hinnant
10909b0af34dSMarshall Clow
10919b0af34dSMarshall Clowtemplate <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
1092*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
1093*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
10949b0af34dSMarshall Clow_ForwardIterator1
10959b0af34dSMarshall Clowfind_first_of(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
10969b0af34dSMarshall Clow              _ForwardIterator2 __first2, _ForwardIterator2 __last2, _BinaryPredicate __pred)
10979b0af34dSMarshall Clow{
10989b0af34dSMarshall Clow    return _VSTD::__find_first_of_ce(__first1, __last1, __first2, __last2, __pred);
10999b0af34dSMarshall Clow}
11009b0af34dSMarshall Clow
11013e519524SHoward Hinnanttemplate <class _ForwardIterator1, class _ForwardIterator2>
1102*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
1103*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
11043e519524SHoward Hinnant_ForwardIterator1
11053e519524SHoward Hinnantfind_first_of(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
11063e519524SHoward Hinnant              _ForwardIterator2 __first2, _ForwardIterator2 __last2)
11073e519524SHoward Hinnant{
11083e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator1>::value_type __v1;
11093e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator2>::value_type __v2;
11109b0af34dSMarshall Clow    return _VSTD::__find_first_of_ce(__first1, __last1, __first2, __last2, __equal_to<__v1, __v2>());
11113e519524SHoward Hinnant}
11123e519524SHoward Hinnant
11133e519524SHoward Hinnant// adjacent_find
11143e519524SHoward Hinnant
11153e519524SHoward Hinnanttemplate <class _ForwardIterator, class _BinaryPredicate>
1116*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
1117*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
11183e519524SHoward Hinnant_ForwardIterator
11193e519524SHoward Hinnantadjacent_find(_ForwardIterator __first, _ForwardIterator __last, _BinaryPredicate __pred)
11203e519524SHoward Hinnant{
11213e519524SHoward Hinnant    if (__first != __last)
11223e519524SHoward Hinnant    {
11233e519524SHoward Hinnant        _ForwardIterator __i = __first;
11243e519524SHoward Hinnant        while (++__i != __last)
11253e519524SHoward Hinnant        {
11263e519524SHoward Hinnant            if (__pred(*__first, *__i))
11273e519524SHoward Hinnant                return __first;
11283e519524SHoward Hinnant            __first = __i;
11293e519524SHoward Hinnant        }
11303e519524SHoward Hinnant    }
11313e519524SHoward Hinnant    return __last;
11323e519524SHoward Hinnant}
11333e519524SHoward Hinnant
11343e519524SHoward Hinnanttemplate <class _ForwardIterator>
1135*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
1136*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
11373e519524SHoward Hinnant_ForwardIterator
11383e519524SHoward Hinnantadjacent_find(_ForwardIterator __first, _ForwardIterator __last)
11393e519524SHoward Hinnant{
11403e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator>::value_type __v;
1141ce48a113SHoward Hinnant    return _VSTD::adjacent_find(__first, __last, __equal_to<__v>());
11423e519524SHoward Hinnant}
11433e519524SHoward Hinnant
11443e519524SHoward Hinnant// count
11453e519524SHoward Hinnant
11463e519524SHoward Hinnanttemplate <class _InputIterator, class _Tp>
1147*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
1148*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
11493e519524SHoward Hinnanttypename iterator_traits<_InputIterator>::difference_type
1150e4383379SHoward Hinnantcount(_InputIterator __first, _InputIterator __last, const _Tp& __value_)
11513e519524SHoward Hinnant{
11523e519524SHoward Hinnant    typename iterator_traits<_InputIterator>::difference_type __r(0);
11533e519524SHoward Hinnant    for (; __first != __last; ++__first)
1154e4383379SHoward Hinnant        if (*__first == __value_)
11553e519524SHoward Hinnant            ++__r;
11563e519524SHoward Hinnant    return __r;
11573e519524SHoward Hinnant}
11583e519524SHoward Hinnant
11593e519524SHoward Hinnant// count_if
11603e519524SHoward Hinnant
11613e519524SHoward Hinnanttemplate <class _InputIterator, class _Predicate>
1162*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
1163*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
11643e519524SHoward Hinnanttypename iterator_traits<_InputIterator>::difference_type
11653e519524SHoward Hinnantcount_if(_InputIterator __first, _InputIterator __last, _Predicate __pred)
11663e519524SHoward Hinnant{
11673e519524SHoward Hinnant    typename iterator_traits<_InputIterator>::difference_type __r(0);
11683e519524SHoward Hinnant    for (; __first != __last; ++__first)
11693e519524SHoward Hinnant        if (__pred(*__first))
11703e519524SHoward Hinnant            ++__r;
11713e519524SHoward Hinnant    return __r;
11723e519524SHoward Hinnant}
11733e519524SHoward Hinnant
11743e519524SHoward Hinnant// mismatch
11753e519524SHoward Hinnant
11763e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
1177*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
1178*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
11793e519524SHoward Hinnantpair<_InputIterator1, _InputIterator2>
11803e519524SHoward Hinnantmismatch(_InputIterator1 __first1, _InputIterator1 __last1,
11813e519524SHoward Hinnant         _InputIterator2 __first2, _BinaryPredicate __pred)
11823e519524SHoward Hinnant{
1183bd7c7b55SMarshall Clow    for (; __first1 != __last1; ++__first1, (void) ++__first2)
11843e519524SHoward Hinnant        if (!__pred(*__first1, *__first2))
11853e519524SHoward Hinnant            break;
11863e519524SHoward Hinnant    return pair<_InputIterator1, _InputIterator2>(__first1, __first2);
11873e519524SHoward Hinnant}
11883e519524SHoward Hinnant
11893e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2>
1190*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
1191*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
11923e519524SHoward Hinnantpair<_InputIterator1, _InputIterator2>
11933e519524SHoward Hinnantmismatch(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2)
11943e519524SHoward Hinnant{
11953e519524SHoward Hinnant    typedef typename iterator_traits<_InputIterator1>::value_type __v1;
11963e519524SHoward Hinnant    typedef typename iterator_traits<_InputIterator2>::value_type __v2;
1197ce48a113SHoward Hinnant    return _VSTD::mismatch(__first1, __last1, __first2, __equal_to<__v1, __v2>());
11983e519524SHoward Hinnant}
11993e519524SHoward Hinnant
12000b0bbd2fSMarshall Clow#if _LIBCPP_STD_VER > 11
12010b0bbd2fSMarshall Clowtemplate <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
1202*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
1203*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
12040b0bbd2fSMarshall Clowpair<_InputIterator1, _InputIterator2>
12050b0bbd2fSMarshall Clowmismatch(_InputIterator1 __first1, _InputIterator1 __last1,
12060b0bbd2fSMarshall Clow         _InputIterator2 __first2, _InputIterator2 __last2,
12070b0bbd2fSMarshall Clow         _BinaryPredicate __pred)
12080b0bbd2fSMarshall Clow{
1209bd7c7b55SMarshall Clow    for (; __first1 != __last1 && __first2 != __last2; ++__first1, (void) ++__first2)
12100b0bbd2fSMarshall Clow        if (!__pred(*__first1, *__first2))
12110b0bbd2fSMarshall Clow            break;
12120b0bbd2fSMarshall Clow    return pair<_InputIterator1, _InputIterator2>(__first1, __first2);
12130b0bbd2fSMarshall Clow}
12140b0bbd2fSMarshall Clow
12150b0bbd2fSMarshall Clowtemplate <class _InputIterator1, class _InputIterator2>
1216*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
1217*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
12180b0bbd2fSMarshall Clowpair<_InputIterator1, _InputIterator2>
12190b0bbd2fSMarshall Clowmismatch(_InputIterator1 __first1, _InputIterator1 __last1,
12200b0bbd2fSMarshall Clow         _InputIterator2 __first2, _InputIterator2 __last2)
12210b0bbd2fSMarshall Clow{
12220b0bbd2fSMarshall Clow    typedef typename iterator_traits<_InputIterator1>::value_type __v1;
12230b0bbd2fSMarshall Clow    typedef typename iterator_traits<_InputIterator2>::value_type __v2;
12240b0bbd2fSMarshall Clow    return _VSTD::mismatch(__first1, __last1, __first2, __last2, __equal_to<__v1, __v2>());
12250b0bbd2fSMarshall Clow}
12260b0bbd2fSMarshall Clow#endif
12270b0bbd2fSMarshall Clow
12283e519524SHoward Hinnant// equal
12293e519524SHoward Hinnant
12303e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
1231*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
1232*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
12333e519524SHoward Hinnantbool
12343e519524SHoward Hinnantequal(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _BinaryPredicate __pred)
12353e519524SHoward Hinnant{
1236910285b2SEric Fiselier    for (; __first1 != __last1; ++__first1, (void) ++__first2)
12373e519524SHoward Hinnant        if (!__pred(*__first1, *__first2))
12383e519524SHoward Hinnant            return false;
12393e519524SHoward Hinnant    return true;
12403e519524SHoward Hinnant}
12413e519524SHoward Hinnant
12423e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2>
1243*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
1244*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
12453e519524SHoward Hinnantbool
12463e519524SHoward Hinnantequal(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2)
12473e519524SHoward Hinnant{
12483e519524SHoward Hinnant    typedef typename iterator_traits<_InputIterator1>::value_type __v1;
12493e519524SHoward Hinnant    typedef typename iterator_traits<_InputIterator2>::value_type __v2;
1250ce48a113SHoward Hinnant    return _VSTD::equal(__first1, __last1, __first2, __equal_to<__v1, __v2>());
12513e519524SHoward Hinnant}
12523e519524SHoward Hinnant
12530b0bbd2fSMarshall Clow#if _LIBCPP_STD_VER > 11
12540b0bbd2fSMarshall Clowtemplate <class _BinaryPredicate, class _InputIterator1, class _InputIterator2>
12556538e28dSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
12560b0bbd2fSMarshall Clowbool
12570b0bbd2fSMarshall Clow__equal(_InputIterator1 __first1, _InputIterator1 __last1,
12580b0bbd2fSMarshall Clow        _InputIterator2 __first2, _InputIterator2 __last2, _BinaryPredicate __pred,
12590b0bbd2fSMarshall Clow        input_iterator_tag, input_iterator_tag )
12600b0bbd2fSMarshall Clow{
1261910285b2SEric Fiselier    for (; __first1 != __last1 && __first2 != __last2; ++__first1, (void) ++__first2)
12620b0bbd2fSMarshall Clow        if (!__pred(*__first1, *__first2))
12630b0bbd2fSMarshall Clow            return false;
12640b0bbd2fSMarshall Clow    return __first1 == __last1 && __first2 == __last2;
12650b0bbd2fSMarshall Clow}
12660b0bbd2fSMarshall Clow
12670b0bbd2fSMarshall Clowtemplate <class _BinaryPredicate, class _RandomAccessIterator1, class _RandomAccessIterator2>
12686538e28dSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
12690b0bbd2fSMarshall Clowbool
12700b0bbd2fSMarshall Clow__equal(_RandomAccessIterator1 __first1, _RandomAccessIterator1 __last1,
12710b0bbd2fSMarshall Clow        _RandomAccessIterator2 __first2, _RandomAccessIterator2 __last2, _BinaryPredicate __pred,
12720b0bbd2fSMarshall Clow      random_access_iterator_tag, random_access_iterator_tag )
12730b0bbd2fSMarshall Clow{
12740b0bbd2fSMarshall Clow    if ( _VSTD::distance(__first1, __last1) != _VSTD::distance(__first2, __last2))
12750b0bbd2fSMarshall Clow        return false;
12760b0bbd2fSMarshall Clow    return _VSTD::equal<_RandomAccessIterator1, _RandomAccessIterator2,
12770b0bbd2fSMarshall Clow                        typename add_lvalue_reference<_BinaryPredicate>::type>
12780b0bbd2fSMarshall Clow                       (__first1, __last1, __first2, __pred );
12790b0bbd2fSMarshall Clow}
12800b0bbd2fSMarshall Clow
12810b0bbd2fSMarshall Clowtemplate <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
1282*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
1283*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
12840b0bbd2fSMarshall Clowbool
12850b0bbd2fSMarshall Clowequal(_InputIterator1 __first1, _InputIterator1 __last1,
12860b0bbd2fSMarshall Clow      _InputIterator2 __first2, _InputIterator2 __last2, _BinaryPredicate __pred )
12870b0bbd2fSMarshall Clow{
12880b0bbd2fSMarshall Clow    return _VSTD::__equal<typename add_lvalue_reference<_BinaryPredicate>::type>
12890b0bbd2fSMarshall Clow       (__first1, __last1, __first2, __last2, __pred,
12900b0bbd2fSMarshall Clow        typename iterator_traits<_InputIterator1>::iterator_category(),
12910b0bbd2fSMarshall Clow        typename iterator_traits<_InputIterator2>::iterator_category());
12920b0bbd2fSMarshall Clow}
12930b0bbd2fSMarshall Clow
12940b0bbd2fSMarshall Clowtemplate <class _InputIterator1, class _InputIterator2>
1295*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
1296*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
12970b0bbd2fSMarshall Clowbool
12980b0bbd2fSMarshall Clowequal(_InputIterator1 __first1, _InputIterator1 __last1,
12990b0bbd2fSMarshall Clow      _InputIterator2 __first2, _InputIterator2 __last2)
13000b0bbd2fSMarshall Clow{
13010b0bbd2fSMarshall Clow    typedef typename iterator_traits<_InputIterator1>::value_type __v1;
13020b0bbd2fSMarshall Clow    typedef typename iterator_traits<_InputIterator2>::value_type __v2;
13030b0bbd2fSMarshall Clow    return _VSTD::__equal(__first1, __last1, __first2, __last2, __equal_to<__v1, __v2>(),
13040b0bbd2fSMarshall Clow        typename iterator_traits<_InputIterator1>::iterator_category(),
13050b0bbd2fSMarshall Clow        typename iterator_traits<_InputIterator2>::iterator_category());
13060b0bbd2fSMarshall Clow}
13070b0bbd2fSMarshall Clow#endif
13080b0bbd2fSMarshall Clow
13093e519524SHoward Hinnant// is_permutation
13103e519524SHoward Hinnant
13113e519524SHoward Hinnanttemplate<class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
1312*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
13133e519524SHoward Hinnantis_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
13143e519524SHoward Hinnant               _ForwardIterator2 __first2, _BinaryPredicate __pred)
13153e519524SHoward Hinnant{
131649c7643cSMarshall Clow//  shorten sequences as much as possible by lopping of any equal prefix
1317910285b2SEric Fiselier    for (; __first1 != __last1; ++__first1, (void) ++__first2)
13183e519524SHoward Hinnant        if (!__pred(*__first1, *__first2))
131949c7643cSMarshall Clow            break;
132049c7643cSMarshall Clow    if (__first1 == __last1)
13213e519524SHoward Hinnant        return true;
132249c7643cSMarshall Clow
13233e519524SHoward Hinnant//  __first1 != __last1 && *__first1 != *__first2
13243e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator1>::difference_type _D1;
1325ce48a113SHoward Hinnant    _D1 __l1 = _VSTD::distance(__first1, __last1);
13263e519524SHoward Hinnant    if (__l1 == _D1(1))
13273e519524SHoward Hinnant        return false;
1328ce48a113SHoward Hinnant    _ForwardIterator2 __last2 = _VSTD::next(__first2, __l1);
13293e519524SHoward Hinnant    // For each element in [f1, l1) see if there are the same number of
13303e519524SHoward Hinnant    //    equal elements in [f2, l2)
13313e519524SHoward Hinnant    for (_ForwardIterator1 __i = __first1; __i != __last1; ++__i)
13323e519524SHoward Hinnant    {
13333e519524SHoward Hinnant    //  Have we already counted the number of *__i in [f1, l1)?
1334939b1623SPeter Collingbourne        _ForwardIterator1 __match = __first1;
1335939b1623SPeter Collingbourne        for (; __match != __i; ++__match)
1336939b1623SPeter Collingbourne            if (__pred(*__match, *__i))
1337939b1623SPeter Collingbourne                break;
1338939b1623SPeter Collingbourne        if (__match == __i) {
13393e519524SHoward Hinnant            // Count number of *__i in [f2, l2)
13403e519524SHoward Hinnant            _D1 __c2 = 0;
13413e519524SHoward Hinnant            for (_ForwardIterator2 __j = __first2; __j != __last2; ++__j)
13423e519524SHoward Hinnant                if (__pred(*__i, *__j))
13433e519524SHoward Hinnant                    ++__c2;
13443e519524SHoward Hinnant            if (__c2 == 0)
13453e519524SHoward Hinnant                return false;
13463e519524SHoward Hinnant            // Count number of *__i in [__i, l1) (we can start with 1)
13473e519524SHoward Hinnant            _D1 __c1 = 1;
1348ce48a113SHoward Hinnant            for (_ForwardIterator1 __j = _VSTD::next(__i); __j != __last1; ++__j)
13493e519524SHoward Hinnant                if (__pred(*__i, *__j))
13503e519524SHoward Hinnant                    ++__c1;
13513e519524SHoward Hinnant            if (__c1 != __c2)
13523e519524SHoward Hinnant                return false;
13533e519524SHoward Hinnant        }
13543e519524SHoward Hinnant    }
13553e519524SHoward Hinnant    return true;
13563e519524SHoward Hinnant}
13573e519524SHoward Hinnant
13583e519524SHoward Hinnanttemplate<class _ForwardIterator1, class _ForwardIterator2>
1359*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
1360*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
13613e519524SHoward Hinnantbool
13623e519524SHoward Hinnantis_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
13633e519524SHoward Hinnant               _ForwardIterator2 __first2)
13643e519524SHoward Hinnant{
13653e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator1>::value_type __v1;
13663e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator2>::value_type __v2;
1367ce48a113SHoward Hinnant    return _VSTD::is_permutation(__first1, __last1, __first2, __equal_to<__v1, __v2>());
13683e519524SHoward Hinnant}
13693e519524SHoward Hinnant
13700b0bbd2fSMarshall Clow#if _LIBCPP_STD_VER > 11
13710b0bbd2fSMarshall Clowtemplate<class _BinaryPredicate, class _ForwardIterator1, class _ForwardIterator2>
137249c7643cSMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
13730b0bbd2fSMarshall Clow__is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
13740b0bbd2fSMarshall Clow                 _ForwardIterator2 __first2, _ForwardIterator2 __last2,
13750b0bbd2fSMarshall Clow                 _BinaryPredicate __pred,
13760b0bbd2fSMarshall Clow                 forward_iterator_tag, forward_iterator_tag )
13770b0bbd2fSMarshall Clow{
137849c7643cSMarshall Clow//  shorten sequences as much as possible by lopping of any equal prefix
1379847ee131SEric Fiselier    for (; __first1 != __last1 && __first2 != __last2; ++__first1, (void) ++__first2)
13800b0bbd2fSMarshall Clow        if (!__pred(*__first1, *__first2))
138149c7643cSMarshall Clow            break;
138249c7643cSMarshall Clow    if (__first1 == __last1)
138349c7643cSMarshall Clow        return __first2 == __last2;
138449c7643cSMarshall Clow    else if (__first2 == __last2)
138549c7643cSMarshall Clow        return false;
138649c7643cSMarshall Clow
13870b0bbd2fSMarshall Clow    typedef typename iterator_traits<_ForwardIterator1>::difference_type _D1;
13880b0bbd2fSMarshall Clow    _D1 __l1 = _VSTD::distance(__first1, __last1);
13890b0bbd2fSMarshall Clow
13900b0bbd2fSMarshall Clow    typedef typename iterator_traits<_ForwardIterator2>::difference_type _D2;
1391fce85ba4SMarshall Clow    _D2 __l2 = _VSTD::distance(__first2, __last2);
13920b0bbd2fSMarshall Clow    if (__l1 != __l2)
13930b0bbd2fSMarshall Clow        return false;
13940b0bbd2fSMarshall Clow
13950b0bbd2fSMarshall Clow    // For each element in [f1, l1) see if there are the same number of
13960b0bbd2fSMarshall Clow    //    equal elements in [f2, l2)
13970b0bbd2fSMarshall Clow    for (_ForwardIterator1 __i = __first1; __i != __last1; ++__i)
13980b0bbd2fSMarshall Clow    {
13990b0bbd2fSMarshall Clow    //  Have we already counted the number of *__i in [f1, l1)?
1400939b1623SPeter Collingbourne        _ForwardIterator1 __match = __first1;
1401939b1623SPeter Collingbourne        for (; __match != __i; ++__match)
1402939b1623SPeter Collingbourne            if (__pred(*__match, *__i))
1403939b1623SPeter Collingbourne                break;
1404939b1623SPeter Collingbourne        if (__match == __i) {
14050b0bbd2fSMarshall Clow            // Count number of *__i in [f2, l2)
14060b0bbd2fSMarshall Clow            _D1 __c2 = 0;
14070b0bbd2fSMarshall Clow            for (_ForwardIterator2 __j = __first2; __j != __last2; ++__j)
14080b0bbd2fSMarshall Clow                if (__pred(*__i, *__j))
14090b0bbd2fSMarshall Clow                    ++__c2;
14100b0bbd2fSMarshall Clow            if (__c2 == 0)
14110b0bbd2fSMarshall Clow                return false;
14120b0bbd2fSMarshall Clow            // Count number of *__i in [__i, l1) (we can start with 1)
14130b0bbd2fSMarshall Clow            _D1 __c1 = 1;
14140b0bbd2fSMarshall Clow            for (_ForwardIterator1 __j = _VSTD::next(__i); __j != __last1; ++__j)
14150b0bbd2fSMarshall Clow                if (__pred(*__i, *__j))
14160b0bbd2fSMarshall Clow                    ++__c1;
14170b0bbd2fSMarshall Clow            if (__c1 != __c2)
14180b0bbd2fSMarshall Clow                return false;
14190b0bbd2fSMarshall Clow        }
14200b0bbd2fSMarshall Clow    }
14210b0bbd2fSMarshall Clow    return true;
14220b0bbd2fSMarshall Clow}
14230b0bbd2fSMarshall Clow
14240b0bbd2fSMarshall Clowtemplate<class _BinaryPredicate, class _RandomAccessIterator1, class _RandomAccessIterator2>
142549c7643cSMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
14260b0bbd2fSMarshall Clow__is_permutation(_RandomAccessIterator1 __first1, _RandomAccessIterator2 __last1,
14270b0bbd2fSMarshall Clow               _RandomAccessIterator1 __first2, _RandomAccessIterator2 __last2,
14280b0bbd2fSMarshall Clow               _BinaryPredicate __pred,
14290b0bbd2fSMarshall Clow               random_access_iterator_tag, random_access_iterator_tag )
14300b0bbd2fSMarshall Clow{
14310b0bbd2fSMarshall Clow    if ( _VSTD::distance(__first1, __last1) != _VSTD::distance(__first2, __last2))
14320b0bbd2fSMarshall Clow        return false;
14330b0bbd2fSMarshall Clow    return _VSTD::is_permutation<_RandomAccessIterator1, _RandomAccessIterator2,
14340b0bbd2fSMarshall Clow                                 typename add_lvalue_reference<_BinaryPredicate>::type>
14350b0bbd2fSMarshall Clow                                (__first1, __last1, __first2, __pred );
14360b0bbd2fSMarshall Clow}
14370b0bbd2fSMarshall Clow
14380b0bbd2fSMarshall Clowtemplate<class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
1439*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
1440*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
14410b0bbd2fSMarshall Clowbool
14420b0bbd2fSMarshall Clowis_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
14430b0bbd2fSMarshall Clow               _ForwardIterator2 __first2, _ForwardIterator2 __last2,
14440b0bbd2fSMarshall Clow               _BinaryPredicate __pred )
14450b0bbd2fSMarshall Clow{
14460b0bbd2fSMarshall Clow    return _VSTD::__is_permutation<typename add_lvalue_reference<_BinaryPredicate>::type>
14470b0bbd2fSMarshall Clow       (__first1, __last1, __first2, __last2, __pred,
14480b0bbd2fSMarshall Clow        typename iterator_traits<_ForwardIterator1>::iterator_category(),
14490b0bbd2fSMarshall Clow        typename iterator_traits<_ForwardIterator2>::iterator_category());
14500b0bbd2fSMarshall Clow}
14510b0bbd2fSMarshall Clow
14520b0bbd2fSMarshall Clowtemplate<class _ForwardIterator1, class _ForwardIterator2>
1453*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
1454*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
14550b0bbd2fSMarshall Clowbool
14560b0bbd2fSMarshall Clowis_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
14570b0bbd2fSMarshall Clow               _ForwardIterator2 __first2, _ForwardIterator2 __last2)
14580b0bbd2fSMarshall Clow{
14590b0bbd2fSMarshall Clow    typedef typename iterator_traits<_ForwardIterator1>::value_type __v1;
14600b0bbd2fSMarshall Clow    typedef typename iterator_traits<_ForwardIterator2>::value_type __v2;
14610b0bbd2fSMarshall Clow    return _VSTD::__is_permutation(__first1, __last1, __first2, __last2,
14620b0bbd2fSMarshall Clow        __equal_to<__v1, __v2>(),
14630b0bbd2fSMarshall Clow        typename iterator_traits<_ForwardIterator1>::iterator_category(),
14640b0bbd2fSMarshall Clow        typename iterator_traits<_ForwardIterator2>::iterator_category());
14650b0bbd2fSMarshall Clow}
14660b0bbd2fSMarshall Clow#endif
14670b0bbd2fSMarshall Clow
14683e519524SHoward Hinnant// search
1469d835e592SMarshall Clow// __search is in <functional>
14703e519524SHoward Hinnant
14713e519524SHoward Hinnanttemplate <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
1472*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
1473*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
14743e519524SHoward Hinnant_ForwardIterator1
14753e519524SHoward Hinnantsearch(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
14763e519524SHoward Hinnant       _ForwardIterator2 __first2, _ForwardIterator2 __last2, _BinaryPredicate __pred)
14773e519524SHoward Hinnant{
1478ce48a113SHoward Hinnant    return _VSTD::__search<typename add_lvalue_reference<_BinaryPredicate>::type>
14793e519524SHoward Hinnant                         (__first1, __last1, __first2, __last2, __pred,
148028cc4ddeSMarshall Clow                          typename iterator_traits<_ForwardIterator1>::iterator_category(),
148128cc4ddeSMarshall Clow                          typename iterator_traits<_ForwardIterator2>::iterator_category())
148228cc4ddeSMarshall Clow            .first;
14833e519524SHoward Hinnant}
14843e519524SHoward Hinnant
14853e519524SHoward Hinnanttemplate <class _ForwardIterator1, class _ForwardIterator2>
1486*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
1487*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
14883e519524SHoward Hinnant_ForwardIterator1
14893e519524SHoward Hinnantsearch(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
14903e519524SHoward Hinnant       _ForwardIterator2 __first2, _ForwardIterator2 __last2)
14913e519524SHoward Hinnant{
149228cc4ddeSMarshall Clow    typedef typename iterator_traits<_ForwardIterator1>::value_type __v1;
149328cc4ddeSMarshall Clow    typedef typename iterator_traits<_ForwardIterator2>::value_type __v2;
1494ce48a113SHoward Hinnant    return _VSTD::search(__first1, __last1, __first2, __last2, __equal_to<__v1, __v2>());
14953e519524SHoward Hinnant}
14963e519524SHoward Hinnant
1497d835e592SMarshall Clow
1498d835e592SMarshall Clow#if _LIBCPP_STD_VER > 14
1499d835e592SMarshall Clowtemplate <class _ForwardIterator, class _Searcher>
1500*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
1501d835e592SMarshall Clow_ForwardIterator search(_ForwardIterator __f, _ForwardIterator __l, const _Searcher &__s)
1502d835e592SMarshall Clow{ return __s(__f, __l).first; }
1503d835e592SMarshall Clow#endif
1504d835e592SMarshall Clow
15053e519524SHoward Hinnant// search_n
15063e519524SHoward Hinnant
15073e519524SHoward Hinnanttemplate <class _BinaryPredicate, class _ForwardIterator, class _Size, class _Tp>
150812f0a779SMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
15093e519524SHoward Hinnant__search_n(_ForwardIterator __first, _ForwardIterator __last,
1510e4383379SHoward Hinnant           _Size __count, const _Tp& __value_, _BinaryPredicate __pred, forward_iterator_tag)
15113e519524SHoward Hinnant{
15123e519524SHoward Hinnant    if (__count <= 0)
15133e519524SHoward Hinnant        return __first;
15143e519524SHoward Hinnant    while (true)
15153e519524SHoward Hinnant    {
1516e4383379SHoward Hinnant        // Find first element in sequence that matchs __value_, with a mininum of loop checks
15173e519524SHoward Hinnant        while (true)
15183e519524SHoward Hinnant        {
1519e4383379SHoward Hinnant            if (__first == __last)  // return __last if no element matches __value_
15203e519524SHoward Hinnant                return __last;
1521e4383379SHoward Hinnant            if (__pred(*__first, __value_))
15223e519524SHoward Hinnant                break;
15233e519524SHoward Hinnant            ++__first;
15243e519524SHoward Hinnant        }
1525e4383379SHoward Hinnant        // *__first matches __value_, now match elements after here
15263e519524SHoward Hinnant        _ForwardIterator __m = __first;
15273e519524SHoward Hinnant        _Size __c(0);
15283e519524SHoward Hinnant        while (true)
15293e519524SHoward Hinnant        {
15303e519524SHoward Hinnant            if (++__c == __count)  // If pattern exhausted, __first is the answer (works for 1 element pattern)
15313e519524SHoward Hinnant                return __first;
15323e519524SHoward Hinnant            if (++__m == __last)  // Otherwise if source exhaused, pattern not found
15333e519524SHoward Hinnant                return __last;
1534e4383379SHoward Hinnant            if (!__pred(*__m, __value_))  // if there is a mismatch, restart with a new __first
15353e519524SHoward Hinnant            {
15363e519524SHoward Hinnant                __first = __m;
15373e519524SHoward Hinnant                ++__first;
15383e519524SHoward Hinnant                break;
15393e519524SHoward Hinnant            }  // else there is a match, check next elements
15403e519524SHoward Hinnant        }
15413e519524SHoward Hinnant    }
15423e519524SHoward Hinnant}
15433e519524SHoward Hinnant
15443e519524SHoward Hinnanttemplate <class _BinaryPredicate, class _RandomAccessIterator, class _Size, class _Tp>
154512f0a779SMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 _RandomAccessIterator
15463e519524SHoward Hinnant__search_n(_RandomAccessIterator __first, _RandomAccessIterator __last,
1547e4383379SHoward Hinnant           _Size __count, const _Tp& __value_, _BinaryPredicate __pred, random_access_iterator_tag)
15483e519524SHoward Hinnant{
15493e519524SHoward Hinnant    if (__count <= 0)
15503e519524SHoward Hinnant        return __first;
15513e519524SHoward Hinnant    _Size __len = static_cast<_Size>(__last - __first);
15523e519524SHoward Hinnant    if (__len < __count)
15533e519524SHoward Hinnant        return __last;
15543e519524SHoward Hinnant    const _RandomAccessIterator __s = __last - (__count - 1);  // Start of pattern match can't go beyond here
15553e519524SHoward Hinnant    while (true)
15563e519524SHoward Hinnant    {
1557e4383379SHoward Hinnant        // Find first element in sequence that matchs __value_, with a mininum of loop checks
15583e519524SHoward Hinnant        while (true)
15593e519524SHoward Hinnant        {
1560b13fcad6SHoward Hinnant            if (__first >= __s)  // return __last if no element matches __value_
15613e519524SHoward Hinnant                return __last;
1562e4383379SHoward Hinnant            if (__pred(*__first, __value_))
15633e519524SHoward Hinnant                break;
15643e519524SHoward Hinnant            ++__first;
15653e519524SHoward Hinnant        }
1566e4383379SHoward Hinnant        // *__first matches __value_, now match elements after here
15673e519524SHoward Hinnant        _RandomAccessIterator __m = __first;
15683e519524SHoward Hinnant        _Size __c(0);
15693e519524SHoward Hinnant        while (true)
15703e519524SHoward Hinnant        {
15713e519524SHoward Hinnant            if (++__c == __count)  // If pattern exhausted, __first is the answer (works for 1 element pattern)
15723e519524SHoward Hinnant                return __first;
15733e519524SHoward Hinnant             ++__m;          // no need to check range on __m because __s guarantees we have enough source
1574e4383379SHoward Hinnant            if (!__pred(*__m, __value_))  // if there is a mismatch, restart with a new __first
15753e519524SHoward Hinnant            {
15763e519524SHoward Hinnant                __first = __m;
15773e519524SHoward Hinnant                ++__first;
15783e519524SHoward Hinnant                break;
15793e519524SHoward Hinnant            }  // else there is a match, check next elements
15803e519524SHoward Hinnant        }
15813e519524SHoward Hinnant    }
15823e519524SHoward Hinnant}
15833e519524SHoward Hinnant
15843e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Size, class _Tp, class _BinaryPredicate>
1585*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
1586*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
15873e519524SHoward Hinnant_ForwardIterator
15883e519524SHoward Hinnantsearch_n(_ForwardIterator __first, _ForwardIterator __last,
1589e4383379SHoward Hinnant         _Size __count, const _Tp& __value_, _BinaryPredicate __pred)
15903e519524SHoward Hinnant{
1591ce48a113SHoward Hinnant    return _VSTD::__search_n<typename add_lvalue_reference<_BinaryPredicate>::type>
159251544023SEric Fiselier           (__first, __last, __convert_to_integral(__count), __value_, __pred,
159351544023SEric Fiselier           typename iterator_traits<_ForwardIterator>::iterator_category());
15943e519524SHoward Hinnant}
15953e519524SHoward Hinnant
15963e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Size, class _Tp>
1597*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
1598*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
15993e519524SHoward Hinnant_ForwardIterator
1600e4383379SHoward Hinnantsearch_n(_ForwardIterator __first, _ForwardIterator __last, _Size __count, const _Tp& __value_)
16013e519524SHoward Hinnant{
16023e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator>::value_type __v;
160351544023SEric Fiselier    return _VSTD::search_n(__first, __last, __convert_to_integral(__count),
160451544023SEric Fiselier                           __value_, __equal_to<__v, _Tp>());
16053e519524SHoward Hinnant}
16063e519524SHoward Hinnant
16073e519524SHoward Hinnant// copy
16083e519524SHoward Hinnanttemplate <class _Iter>
16093e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
16103e519524SHoward Hinnant_Iter
16113e519524SHoward Hinnant__unwrap_iter(_Iter __i)
16123e519524SHoward Hinnant{
16133e519524SHoward Hinnant    return __i;
16143e519524SHoward Hinnant}
16153e519524SHoward Hinnant
16163e519524SHoward Hinnanttemplate <class _Tp>
16175b7c98e5SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY
16183e519524SHoward Hinnanttypename enable_if
16193e519524SHoward Hinnant<
1620ca740483SHoward Hinnant    is_trivially_copy_assignable<_Tp>::value,
16213e519524SHoward Hinnant    _Tp*
16223e519524SHoward Hinnant>::type
16233e519524SHoward Hinnant__unwrap_iter(move_iterator<_Tp*> __i)
16243e519524SHoward Hinnant{
16253e519524SHoward Hinnant    return __i.base();
16263e519524SHoward Hinnant}
16273e519524SHoward Hinnant
1628fc88dbd2SHoward Hinnant#if _LIBCPP_DEBUG_LEVEL < 2
1629fc88dbd2SHoward Hinnant
16303e519524SHoward Hinnanttemplate <class _Tp>
16319cad5025SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
16323e519524SHoward Hinnanttypename enable_if
16333e519524SHoward Hinnant<
1634ca740483SHoward Hinnant    is_trivially_copy_assignable<_Tp>::value,
16353e519524SHoward Hinnant    _Tp*
16363e519524SHoward Hinnant>::type
16373e519524SHoward Hinnant__unwrap_iter(__wrap_iter<_Tp*> __i)
16383e519524SHoward Hinnant{
16393e519524SHoward Hinnant    return __i.base();
16403e519524SHoward Hinnant}
16413e519524SHoward Hinnant
1642c8879ab2SMarshall Clowtemplate <class _Tp>
1643c8879ab2SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1644c8879ab2SMarshall Clowtypename enable_if
1645c8879ab2SMarshall Clow<
1646c8879ab2SMarshall Clow    is_trivially_copy_assignable<_Tp>::value,
1647c8879ab2SMarshall Clow    const _Tp*
1648c8879ab2SMarshall Clow>::type
1649c8879ab2SMarshall Clow__unwrap_iter(__wrap_iter<const _Tp*> __i)
1650c8879ab2SMarshall Clow{
1651c8879ab2SMarshall Clow    return __i.base();
1652c8879ab2SMarshall Clow}
1653c8879ab2SMarshall Clow
165414bd0bf0SEric Fiselier#else
165514bd0bf0SEric Fiselier
165614bd0bf0SEric Fiseliertemplate <class _Tp>
16579cad5025SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
165814bd0bf0SEric Fiseliertypename enable_if
165914bd0bf0SEric Fiselier<
166014bd0bf0SEric Fiselier    is_trivially_copy_assignable<_Tp>::value,
166114bd0bf0SEric Fiselier    __wrap_iter<_Tp*>
166214bd0bf0SEric Fiselier>::type
166314bd0bf0SEric Fiselier__unwrap_iter(__wrap_iter<_Tp*> __i)
166414bd0bf0SEric Fiselier{
166514bd0bf0SEric Fiselier    return __i;
166614bd0bf0SEric Fiselier}
166714bd0bf0SEric Fiselier
1668fc88dbd2SHoward Hinnant#endif  // _LIBCPP_DEBUG_LEVEL < 2
1669fc88dbd2SHoward Hinnant
16703e519524SHoward Hinnanttemplate <class _InputIterator, class _OutputIterator>
16713e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
16723e519524SHoward Hinnant_OutputIterator
16733e519524SHoward Hinnant__copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
16743e519524SHoward Hinnant{
1675910285b2SEric Fiselier    for (; __first != __last; ++__first, (void) ++__result)
16763e519524SHoward Hinnant        *__result = *__first;
16773e519524SHoward Hinnant    return __result;
16783e519524SHoward Hinnant}
16793e519524SHoward Hinnant
16803e519524SHoward Hinnanttemplate <class _Tp, class _Up>
16813e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
16823e519524SHoward Hinnanttypename enable_if
16833e519524SHoward Hinnant<
16843e519524SHoward Hinnant    is_same<typename remove_const<_Tp>::type, _Up>::value &&
1685ca740483SHoward Hinnant    is_trivially_copy_assignable<_Up>::value,
16863e519524SHoward Hinnant    _Up*
16873e519524SHoward Hinnant>::type
16883e519524SHoward Hinnant__copy(_Tp* __first, _Tp* __last, _Up* __result)
16893e519524SHoward Hinnant{
16903e519524SHoward Hinnant    const size_t __n = static_cast<size_t>(__last - __first);
16915b312052SMarshall Clow    if (__n > 0)
1692ce48a113SHoward Hinnant        _VSTD::memmove(__result, __first, __n * sizeof(_Up));
16933e519524SHoward Hinnant    return __result + __n;
16943e519524SHoward Hinnant}
16953e519524SHoward Hinnant
16963e519524SHoward Hinnanttemplate <class _InputIterator, class _OutputIterator>
16973e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
16983e519524SHoward Hinnant_OutputIterator
16993e519524SHoward Hinnantcopy(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
17003e519524SHoward Hinnant{
1701ce48a113SHoward Hinnant    return _VSTD::__copy(__unwrap_iter(__first), __unwrap_iter(__last), __unwrap_iter(__result));
17023e519524SHoward Hinnant}
17033e519524SHoward Hinnant
17043e519524SHoward Hinnant// copy_backward
17053e519524SHoward Hinnant
1706d3d4356fSHoward Hinnanttemplate <class _BidirectionalIterator, class _OutputIterator>
17073e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
17083e519524SHoward Hinnant_OutputIterator
1709d3d4356fSHoward Hinnant__copy_backward(_BidirectionalIterator __first, _BidirectionalIterator __last, _OutputIterator __result)
17103e519524SHoward Hinnant{
17113e519524SHoward Hinnant    while (__first != __last)
17123e519524SHoward Hinnant        *--__result = *--__last;
17133e519524SHoward Hinnant    return __result;
17143e519524SHoward Hinnant}
17153e519524SHoward Hinnant
17163e519524SHoward Hinnanttemplate <class _Tp, class _Up>
17173e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
17183e519524SHoward Hinnanttypename enable_if
17193e519524SHoward Hinnant<
17203e519524SHoward Hinnant    is_same<typename remove_const<_Tp>::type, _Up>::value &&
1721ca740483SHoward Hinnant    is_trivially_copy_assignable<_Up>::value,
17223e519524SHoward Hinnant    _Up*
17233e519524SHoward Hinnant>::type
17243e519524SHoward Hinnant__copy_backward(_Tp* __first, _Tp* __last, _Up* __result)
17253e519524SHoward Hinnant{
17263e519524SHoward Hinnant    const size_t __n = static_cast<size_t>(__last - __first);
17275b312052SMarshall Clow    if (__n > 0)
17285b312052SMarshall Clow    {
17293e519524SHoward Hinnant        __result -= __n;
1730ce48a113SHoward Hinnant        _VSTD::memmove(__result, __first, __n * sizeof(_Up));
17315b312052SMarshall Clow    }
17323e519524SHoward Hinnant    return __result;
17333e519524SHoward Hinnant}
17343e519524SHoward Hinnant
17353e519524SHoward Hinnanttemplate <class _BidirectionalIterator1, class _BidirectionalIterator2>
17363e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
17373e519524SHoward Hinnant_BidirectionalIterator2
17383e519524SHoward Hinnantcopy_backward(_BidirectionalIterator1 __first, _BidirectionalIterator1 __last,
17393e519524SHoward Hinnant              _BidirectionalIterator2 __result)
17403e519524SHoward Hinnant{
1741fd838227SEric Fiselier    return _VSTD::__copy_backward(__unwrap_iter(__first),
1742fd838227SEric Fiselier                                  __unwrap_iter(__last),
1743fd838227SEric Fiselier                                  __unwrap_iter(__result));
17443e519524SHoward Hinnant}
17453e519524SHoward Hinnant
17463e519524SHoward Hinnant// copy_if
17473e519524SHoward Hinnant
17483e519524SHoward Hinnanttemplate<class _InputIterator, class _OutputIterator, class _Predicate>
17493e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
17503e519524SHoward Hinnant_OutputIterator
17513e519524SHoward Hinnantcopy_if(_InputIterator __first, _InputIterator __last,
17523e519524SHoward Hinnant        _OutputIterator __result, _Predicate __pred)
17533e519524SHoward Hinnant{
17543e519524SHoward Hinnant    for (; __first != __last; ++__first)
17553e519524SHoward Hinnant    {
17563e519524SHoward Hinnant        if (__pred(*__first))
17573e519524SHoward Hinnant        {
17583e519524SHoward Hinnant            *__result = *__first;
17593e519524SHoward Hinnant            ++__result;
17603e519524SHoward Hinnant        }
17613e519524SHoward Hinnant    }
17623e519524SHoward Hinnant    return __result;
17633e519524SHoward Hinnant}
17643e519524SHoward Hinnant
17653e519524SHoward Hinnant// copy_n
17663e519524SHoward Hinnant
17673e519524SHoward Hinnanttemplate<class _InputIterator, class _Size, class _OutputIterator>
17683e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
17693e519524SHoward Hinnanttypename enable_if
17703e519524SHoward Hinnant<
17713e519524SHoward Hinnant    __is_input_iterator<_InputIterator>::value &&
17723e519524SHoward Hinnant   !__is_random_access_iterator<_InputIterator>::value,
17733e519524SHoward Hinnant    _OutputIterator
17743e519524SHoward Hinnant>::type
177551544023SEric Fiseliercopy_n(_InputIterator __first, _Size __orig_n, _OutputIterator __result)
17763e519524SHoward Hinnant{
177751544023SEric Fiselier    typedef decltype(__convert_to_integral(__orig_n)) _IntegralSize;
177851544023SEric Fiselier    _IntegralSize __n = __orig_n;
177999847d2bSHoward Hinnant    if (__n > 0)
178099847d2bSHoward Hinnant    {
17813e519524SHoward Hinnant        *__result = *__first;
178299847d2bSHoward Hinnant        ++__result;
178399847d2bSHoward Hinnant        for (--__n; __n > 0; --__n)
178499847d2bSHoward Hinnant        {
178599847d2bSHoward Hinnant            ++__first;
178699847d2bSHoward Hinnant            *__result = *__first;
178799847d2bSHoward Hinnant            ++__result;
178899847d2bSHoward Hinnant        }
178999847d2bSHoward Hinnant    }
17903e519524SHoward Hinnant    return __result;
17913e519524SHoward Hinnant}
17923e519524SHoward Hinnant
17933e519524SHoward Hinnanttemplate<class _InputIterator, class _Size, class _OutputIterator>
17943e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
17953e519524SHoward Hinnanttypename enable_if
17963e519524SHoward Hinnant<
17973e519524SHoward Hinnant    __is_random_access_iterator<_InputIterator>::value,
17983e519524SHoward Hinnant    _OutputIterator
17993e519524SHoward Hinnant>::type
180051544023SEric Fiseliercopy_n(_InputIterator __first, _Size __orig_n, _OutputIterator __result)
18013e519524SHoward Hinnant{
180251544023SEric Fiselier    typedef decltype(__convert_to_integral(__orig_n)) _IntegralSize;
180351544023SEric Fiselier    _IntegralSize __n = __orig_n;
1804ce48a113SHoward Hinnant    return _VSTD::copy(__first, __first + __n, __result);
18053e519524SHoward Hinnant}
18063e519524SHoward Hinnant
18073e519524SHoward Hinnant// move
18083e519524SHoward Hinnant
18093e519524SHoward Hinnanttemplate <class _InputIterator, class _OutputIterator>
18103e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
18113e519524SHoward Hinnant_OutputIterator
18123e519524SHoward Hinnant__move(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
18133e519524SHoward Hinnant{
1814910285b2SEric Fiselier    for (; __first != __last; ++__first, (void) ++__result)
1815ce48a113SHoward Hinnant        *__result = _VSTD::move(*__first);
18163e519524SHoward Hinnant    return __result;
18173e519524SHoward Hinnant}
18183e519524SHoward Hinnant
18193e519524SHoward Hinnanttemplate <class _Tp, class _Up>
18203e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
18213e519524SHoward Hinnanttypename enable_if
18223e519524SHoward Hinnant<
18233e519524SHoward Hinnant    is_same<typename remove_const<_Tp>::type, _Up>::value &&
1824ca740483SHoward Hinnant    is_trivially_copy_assignable<_Up>::value,
18253e519524SHoward Hinnant    _Up*
18263e519524SHoward Hinnant>::type
18273e519524SHoward Hinnant__move(_Tp* __first, _Tp* __last, _Up* __result)
18283e519524SHoward Hinnant{
18293e519524SHoward Hinnant    const size_t __n = static_cast<size_t>(__last - __first);
18305b312052SMarshall Clow    if (__n > 0)
1831ce48a113SHoward Hinnant        _VSTD::memmove(__result, __first, __n * sizeof(_Up));
18323e519524SHoward Hinnant    return __result + __n;
18333e519524SHoward Hinnant}
18343e519524SHoward Hinnant
18353e519524SHoward Hinnanttemplate <class _InputIterator, class _OutputIterator>
18363e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
18373e519524SHoward Hinnant_OutputIterator
18383e519524SHoward Hinnantmove(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
18393e519524SHoward Hinnant{
1840ce48a113SHoward Hinnant    return _VSTD::__move(__unwrap_iter(__first), __unwrap_iter(__last), __unwrap_iter(__result));
18413e519524SHoward Hinnant}
18423e519524SHoward Hinnant
18433e519524SHoward Hinnant// move_backward
18443e519524SHoward Hinnant
18453e519524SHoward Hinnanttemplate <class _InputIterator, class _OutputIterator>
18463e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
18473e519524SHoward Hinnant_OutputIterator
18483e519524SHoward Hinnant__move_backward(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
18493e519524SHoward Hinnant{
18503e519524SHoward Hinnant    while (__first != __last)
1851ce48a113SHoward Hinnant        *--__result = _VSTD::move(*--__last);
18523e519524SHoward Hinnant    return __result;
18533e519524SHoward Hinnant}
18543e519524SHoward Hinnant
18553e519524SHoward Hinnanttemplate <class _Tp, class _Up>
18563e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
18573e519524SHoward Hinnanttypename enable_if
18583e519524SHoward Hinnant<
18593e519524SHoward Hinnant    is_same<typename remove_const<_Tp>::type, _Up>::value &&
1860ca740483SHoward Hinnant    is_trivially_copy_assignable<_Up>::value,
18613e519524SHoward Hinnant    _Up*
18623e519524SHoward Hinnant>::type
18633e519524SHoward Hinnant__move_backward(_Tp* __first, _Tp* __last, _Up* __result)
18643e519524SHoward Hinnant{
18653e519524SHoward Hinnant    const size_t __n = static_cast<size_t>(__last - __first);
18665b312052SMarshall Clow    if (__n > 0)
18675b312052SMarshall Clow    {
18683e519524SHoward Hinnant        __result -= __n;
1869ce48a113SHoward Hinnant        _VSTD::memmove(__result, __first, __n * sizeof(_Up));
18705b312052SMarshall Clow    }
18713e519524SHoward Hinnant    return __result;
18723e519524SHoward Hinnant}
18733e519524SHoward Hinnant
18743e519524SHoward Hinnanttemplate <class _BidirectionalIterator1, class _BidirectionalIterator2>
18753e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
18763e519524SHoward Hinnant_BidirectionalIterator2
18773e519524SHoward Hinnantmove_backward(_BidirectionalIterator1 __first, _BidirectionalIterator1 __last,
18783e519524SHoward Hinnant              _BidirectionalIterator2 __result)
18793e519524SHoward Hinnant{
1880ce48a113SHoward Hinnant    return _VSTD::__move_backward(__unwrap_iter(__first), __unwrap_iter(__last), __unwrap_iter(__result));
18813e519524SHoward Hinnant}
18823e519524SHoward Hinnant
18833e519524SHoward Hinnant// iter_swap
18843e519524SHoward Hinnant
1885a676f7d3SHoward Hinnant// moved to <type_traits> for better swap / noexcept support
18863e519524SHoward Hinnant
18873e519524SHoward Hinnant// transform
18883e519524SHoward Hinnant
18893e519524SHoward Hinnanttemplate <class _InputIterator, class _OutputIterator, class _UnaryOperation>
189099894b61SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
18913e519524SHoward Hinnant_OutputIterator
18923e519524SHoward Hinnanttransform(_InputIterator __first, _InputIterator __last, _OutputIterator __result, _UnaryOperation __op)
18933e519524SHoward Hinnant{
1894910285b2SEric Fiselier    for (; __first != __last; ++__first, (void) ++__result)
18953e519524SHoward Hinnant        *__result = __op(*__first);
18963e519524SHoward Hinnant    return __result;
18973e519524SHoward Hinnant}
18983e519524SHoward Hinnant
18993e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _BinaryOperation>
190099894b61SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
19013e519524SHoward Hinnant_OutputIterator
19023e519524SHoward Hinnanttransform(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2,
19033e519524SHoward Hinnant          _OutputIterator __result, _BinaryOperation __binary_op)
19043e519524SHoward Hinnant{
1905910285b2SEric Fiselier    for (; __first1 != __last1; ++__first1, (void) ++__first2, ++__result)
19063e519524SHoward Hinnant        *__result = __binary_op(*__first1, *__first2);
19073e519524SHoward Hinnant    return __result;
19083e519524SHoward Hinnant}
19093e519524SHoward Hinnant
19103e519524SHoward Hinnant// replace
19113e519524SHoward Hinnant
19123e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Tp>
191312c7423fSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
19143e519524SHoward Hinnantvoid
19153e519524SHoward Hinnantreplace(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __old_value, const _Tp& __new_value)
19163e519524SHoward Hinnant{
19173e519524SHoward Hinnant    for (; __first != __last; ++__first)
19183e519524SHoward Hinnant        if (*__first == __old_value)
19193e519524SHoward Hinnant            *__first = __new_value;
19203e519524SHoward Hinnant}
19213e519524SHoward Hinnant
19223e519524SHoward Hinnant// replace_if
19233e519524SHoward Hinnant
19243e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Predicate, class _Tp>
192512c7423fSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
19263e519524SHoward Hinnantvoid
19273e519524SHoward Hinnantreplace_if(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred, const _Tp& __new_value)
19283e519524SHoward Hinnant{
19293e519524SHoward Hinnant    for (; __first != __last; ++__first)
19303e519524SHoward Hinnant        if (__pred(*__first))
19313e519524SHoward Hinnant            *__first = __new_value;
19323e519524SHoward Hinnant}
19333e519524SHoward Hinnant
19343e519524SHoward Hinnant// replace_copy
19353e519524SHoward Hinnant
19363e519524SHoward Hinnanttemplate <class _InputIterator, class _OutputIterator, class _Tp>
193712c7423fSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
19383e519524SHoward Hinnant_OutputIterator
19393e519524SHoward Hinnantreplace_copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result,
19403e519524SHoward Hinnant             const _Tp& __old_value, const _Tp& __new_value)
19413e519524SHoward Hinnant{
1942910285b2SEric Fiselier    for (; __first != __last; ++__first, (void) ++__result)
19433e519524SHoward Hinnant        if (*__first == __old_value)
19443e519524SHoward Hinnant            *__result = __new_value;
19453e519524SHoward Hinnant        else
19463e519524SHoward Hinnant            *__result = *__first;
19473e519524SHoward Hinnant    return __result;
19483e519524SHoward Hinnant}
19493e519524SHoward Hinnant
19503e519524SHoward Hinnant// replace_copy_if
19513e519524SHoward Hinnant
19523e519524SHoward Hinnanttemplate <class _InputIterator, class _OutputIterator, class _Predicate, class _Tp>
195312c7423fSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
19543e519524SHoward Hinnant_OutputIterator
19553e519524SHoward Hinnantreplace_copy_if(_InputIterator __first, _InputIterator __last, _OutputIterator __result,
19563e519524SHoward Hinnant                _Predicate __pred, const _Tp& __new_value)
19573e519524SHoward Hinnant{
1958910285b2SEric Fiselier    for (; __first != __last; ++__first, (void) ++__result)
19593e519524SHoward Hinnant        if (__pred(*__first))
19603e519524SHoward Hinnant            *__result = __new_value;
19613e519524SHoward Hinnant        else
19623e519524SHoward Hinnant            *__result = *__first;
19633e519524SHoward Hinnant    return __result;
19643e519524SHoward Hinnant}
19653e519524SHoward Hinnant
19663e519524SHoward Hinnant// fill_n
19673e519524SHoward Hinnant
19683e519524SHoward Hinnanttemplate <class _OutputIterator, class _Size, class _Tp>
19694bfb9313SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
19703e519524SHoward Hinnant_OutputIterator
19710f242beaSHoward Hinnant__fill_n(_OutputIterator __first, _Size __n, const _Tp& __value_)
19723e519524SHoward Hinnant{
1973910285b2SEric Fiselier    for (; __n > 0; ++__first, (void) --__n)
1974e4383379SHoward Hinnant        *__first = __value_;
19753e519524SHoward Hinnant    return __first;
19763e519524SHoward Hinnant}
19773e519524SHoward Hinnant
19783e519524SHoward Hinnanttemplate <class _OutputIterator, class _Size, class _Tp>
19794bfb9313SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
19803e519524SHoward Hinnant_OutputIterator
1981e4383379SHoward Hinnantfill_n(_OutputIterator __first, _Size __n, const _Tp& __value_)
19823e519524SHoward Hinnant{
198351544023SEric Fiselier   return _VSTD::__fill_n(__first, __convert_to_integral(__n), __value_);
19843e519524SHoward Hinnant}
19853e519524SHoward Hinnant
19863e519524SHoward Hinnant// fill
19873e519524SHoward Hinnant
19883e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Tp>
19894bfb9313SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
19903e519524SHoward Hinnantvoid
1991e4383379SHoward Hinnant__fill(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, forward_iterator_tag)
19923e519524SHoward Hinnant{
19933e519524SHoward Hinnant    for (; __first != __last; ++__first)
1994e4383379SHoward Hinnant        *__first = __value_;
19953e519524SHoward Hinnant}
19963e519524SHoward Hinnant
19973e519524SHoward Hinnanttemplate <class _RandomAccessIterator, class _Tp>
19984bfb9313SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
19993e519524SHoward Hinnantvoid
2000e4383379SHoward Hinnant__fill(_RandomAccessIterator __first, _RandomAccessIterator __last, const _Tp& __value_, random_access_iterator_tag)
20013e519524SHoward Hinnant{
2002e4383379SHoward Hinnant    _VSTD::fill_n(__first, __last - __first, __value_);
20033e519524SHoward Hinnant}
20043e519524SHoward Hinnant
20053e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Tp>
20064bfb9313SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
20073e519524SHoward Hinnantvoid
2008e4383379SHoward Hinnantfill(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_)
20093e519524SHoward Hinnant{
2010e4383379SHoward Hinnant    _VSTD::__fill(__first, __last, __value_, typename iterator_traits<_ForwardIterator>::iterator_category());
20113e519524SHoward Hinnant}
20123e519524SHoward Hinnant
20133e519524SHoward Hinnant// generate
20143e519524SHoward Hinnant
20153e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Generator>
20164bfb9313SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
20173e519524SHoward Hinnantvoid
20183e519524SHoward Hinnantgenerate(_ForwardIterator __first, _ForwardIterator __last, _Generator __gen)
20193e519524SHoward Hinnant{
20203e519524SHoward Hinnant    for (; __first != __last; ++__first)
20213e519524SHoward Hinnant        *__first = __gen();
20223e519524SHoward Hinnant}
20233e519524SHoward Hinnant
20243e519524SHoward Hinnant// generate_n
20253e519524SHoward Hinnant
20263e519524SHoward Hinnanttemplate <class _OutputIterator, class _Size, class _Generator>
20274bfb9313SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
20283e519524SHoward Hinnant_OutputIterator
202951544023SEric Fiseliergenerate_n(_OutputIterator __first, _Size __orig_n, _Generator __gen)
20303e519524SHoward Hinnant{
203151544023SEric Fiselier    typedef decltype(__convert_to_integral(__orig_n)) _IntegralSize;
203251544023SEric Fiselier    _IntegralSize __n = __orig_n;
2033910285b2SEric Fiselier    for (; __n > 0; ++__first, (void) --__n)
20343e519524SHoward Hinnant        *__first = __gen();
20353e519524SHoward Hinnant    return __first;
20363e519524SHoward Hinnant}
20373e519524SHoward Hinnant
20383e519524SHoward Hinnant// remove
20393e519524SHoward Hinnant
20403e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Tp>
2041*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
2042e4383379SHoward Hinnantremove(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_)
20433e519524SHoward Hinnant{
2044e4383379SHoward Hinnant    __first = _VSTD::find(__first, __last, __value_);
20453e519524SHoward Hinnant    if (__first != __last)
20463e519524SHoward Hinnant    {
20473e519524SHoward Hinnant        _ForwardIterator __i = __first;
20483e519524SHoward Hinnant        while (++__i != __last)
20493e519524SHoward Hinnant        {
2050e4383379SHoward Hinnant            if (!(*__i == __value_))
20513e519524SHoward Hinnant            {
2052ce48a113SHoward Hinnant                *__first = _VSTD::move(*__i);
20533e519524SHoward Hinnant                ++__first;
20543e519524SHoward Hinnant            }
20553e519524SHoward Hinnant        }
20563e519524SHoward Hinnant    }
20573e519524SHoward Hinnant    return __first;
20583e519524SHoward Hinnant}
20593e519524SHoward Hinnant
20603e519524SHoward Hinnant// remove_if
20613e519524SHoward Hinnant
20623e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Predicate>
2063*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
20643e519524SHoward Hinnantremove_if(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred)
20653e519524SHoward Hinnant{
2066ce48a113SHoward Hinnant    __first = _VSTD::find_if<_ForwardIterator, typename add_lvalue_reference<_Predicate>::type>
20673e519524SHoward Hinnant                           (__first, __last, __pred);
20683e519524SHoward Hinnant    if (__first != __last)
20693e519524SHoward Hinnant    {
20703e519524SHoward Hinnant        _ForwardIterator __i = __first;
20713e519524SHoward Hinnant        while (++__i != __last)
20723e519524SHoward Hinnant        {
20733e519524SHoward Hinnant            if (!__pred(*__i))
20743e519524SHoward Hinnant            {
2075ce48a113SHoward Hinnant                *__first = _VSTD::move(*__i);
20763e519524SHoward Hinnant                ++__first;
20773e519524SHoward Hinnant            }
20783e519524SHoward Hinnant        }
20793e519524SHoward Hinnant    }
20803e519524SHoward Hinnant    return __first;
20813e519524SHoward Hinnant}
20823e519524SHoward Hinnant
20833e519524SHoward Hinnant// remove_copy
20843e519524SHoward Hinnant
20853e519524SHoward Hinnanttemplate <class _InputIterator, class _OutputIterator, class _Tp>
2086e8ea8296SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
20873e519524SHoward Hinnant_OutputIterator
2088e4383379SHoward Hinnantremove_copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result, const _Tp& __value_)
20893e519524SHoward Hinnant{
20903e519524SHoward Hinnant    for (; __first != __last; ++__first)
20913e519524SHoward Hinnant    {
2092e4383379SHoward Hinnant        if (!(*__first == __value_))
20933e519524SHoward Hinnant        {
20943e519524SHoward Hinnant            *__result = *__first;
20953e519524SHoward Hinnant            ++__result;
20963e519524SHoward Hinnant        }
20973e519524SHoward Hinnant    }
20983e519524SHoward Hinnant    return __result;
20993e519524SHoward Hinnant}
21003e519524SHoward Hinnant
21013e519524SHoward Hinnant// remove_copy_if
21023e519524SHoward Hinnant
21033e519524SHoward Hinnanttemplate <class _InputIterator, class _OutputIterator, class _Predicate>
2104e8ea8296SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
21053e519524SHoward Hinnant_OutputIterator
21063e519524SHoward Hinnantremove_copy_if(_InputIterator __first, _InputIterator __last, _OutputIterator __result, _Predicate __pred)
21073e519524SHoward Hinnant{
21083e519524SHoward Hinnant    for (; __first != __last; ++__first)
21093e519524SHoward Hinnant    {
21103e519524SHoward Hinnant        if (!__pred(*__first))
21113e519524SHoward Hinnant        {
21123e519524SHoward Hinnant            *__result = *__first;
21133e519524SHoward Hinnant            ++__result;
21143e519524SHoward Hinnant        }
21153e519524SHoward Hinnant    }
21163e519524SHoward Hinnant    return __result;
21173e519524SHoward Hinnant}
21183e519524SHoward Hinnant
21193e519524SHoward Hinnant// unique
21203e519524SHoward Hinnant
21213e519524SHoward Hinnanttemplate <class _ForwardIterator, class _BinaryPredicate>
2122*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
21233e519524SHoward Hinnantunique(_ForwardIterator __first, _ForwardIterator __last, _BinaryPredicate __pred)
21243e519524SHoward Hinnant{
2125ce48a113SHoward Hinnant    __first = _VSTD::adjacent_find<_ForwardIterator, typename add_lvalue_reference<_BinaryPredicate>::type>
21263e519524SHoward Hinnant                                 (__first, __last, __pred);
21273e519524SHoward Hinnant    if (__first != __last)
21283e519524SHoward Hinnant    {
21293e519524SHoward Hinnant        // ...  a  a  ?  ...
21303e519524SHoward Hinnant        //      f     i
21313e519524SHoward Hinnant        _ForwardIterator __i = __first;
21323e519524SHoward Hinnant        for (++__i; ++__i != __last;)
21333e519524SHoward Hinnant            if (!__pred(*__first, *__i))
2134ce48a113SHoward Hinnant                *++__first = _VSTD::move(*__i);
21353e519524SHoward Hinnant        ++__first;
21363e519524SHoward Hinnant    }
21373e519524SHoward Hinnant    return __first;
21383e519524SHoward Hinnant}
21393e519524SHoward Hinnant
21403e519524SHoward Hinnanttemplate <class _ForwardIterator>
2141*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
2142*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
21433e519524SHoward Hinnant_ForwardIterator
21443e519524SHoward Hinnantunique(_ForwardIterator __first, _ForwardIterator __last)
21453e519524SHoward Hinnant{
21463e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator>::value_type __v;
2147ce48a113SHoward Hinnant    return _VSTD::unique(__first, __last, __equal_to<__v>());
21483e519524SHoward Hinnant}
21493e519524SHoward Hinnant
21503e519524SHoward Hinnant// unique_copy
21513e519524SHoward Hinnant
21523e519524SHoward Hinnanttemplate <class _BinaryPredicate, class _InputIterator, class _OutputIterator>
21534bfb9313SMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 _OutputIterator
21543e519524SHoward Hinnant__unique_copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result, _BinaryPredicate __pred,
21553e519524SHoward Hinnant              input_iterator_tag, output_iterator_tag)
21563e519524SHoward Hinnant{
21573e519524SHoward Hinnant    if (__first != __last)
21583e519524SHoward Hinnant    {
21593e519524SHoward Hinnant        typename iterator_traits<_InputIterator>::value_type __t(*__first);
21603e519524SHoward Hinnant        *__result = __t;
21613e519524SHoward Hinnant        ++__result;
21623e519524SHoward Hinnant        while (++__first != __last)
21633e519524SHoward Hinnant        {
21643e519524SHoward Hinnant            if (!__pred(__t, *__first))
21653e519524SHoward Hinnant            {
21663e519524SHoward Hinnant                __t = *__first;
21673e519524SHoward Hinnant                *__result = __t;
21683e519524SHoward Hinnant                ++__result;
21693e519524SHoward Hinnant            }
21703e519524SHoward Hinnant        }
21713e519524SHoward Hinnant    }
21723e519524SHoward Hinnant    return __result;
21733e519524SHoward Hinnant}
21743e519524SHoward Hinnant
21753e519524SHoward Hinnanttemplate <class _BinaryPredicate, class _ForwardIterator, class _OutputIterator>
21764bfb9313SMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 _OutputIterator
21773e519524SHoward Hinnant__unique_copy(_ForwardIterator __first, _ForwardIterator __last, _OutputIterator __result, _BinaryPredicate __pred,
21783e519524SHoward Hinnant              forward_iterator_tag, output_iterator_tag)
21793e519524SHoward Hinnant{
21803e519524SHoward Hinnant    if (__first != __last)
21813e519524SHoward Hinnant    {
21823e519524SHoward Hinnant        _ForwardIterator __i = __first;
21833e519524SHoward Hinnant        *__result = *__i;
21843e519524SHoward Hinnant        ++__result;
21853e519524SHoward Hinnant        while (++__first != __last)
21863e519524SHoward Hinnant        {
21873e519524SHoward Hinnant            if (!__pred(*__i, *__first))
21883e519524SHoward Hinnant            {
21893e519524SHoward Hinnant                *__result = *__first;
21903e519524SHoward Hinnant                ++__result;
21913e519524SHoward Hinnant                __i = __first;
21923e519524SHoward Hinnant            }
21933e519524SHoward Hinnant        }
21943e519524SHoward Hinnant    }
21953e519524SHoward Hinnant    return __result;
21963e519524SHoward Hinnant}
21973e519524SHoward Hinnant
21983e519524SHoward Hinnanttemplate <class _BinaryPredicate, class _InputIterator, class _ForwardIterator>
21994bfb9313SMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
22003e519524SHoward Hinnant__unique_copy(_InputIterator __first, _InputIterator __last, _ForwardIterator __result, _BinaryPredicate __pred,
22013e519524SHoward Hinnant              input_iterator_tag, forward_iterator_tag)
22023e519524SHoward Hinnant{
22033e519524SHoward Hinnant    if (__first != __last)
22043e519524SHoward Hinnant    {
22053e519524SHoward Hinnant        *__result = *__first;
22063e519524SHoward Hinnant        while (++__first != __last)
22073e519524SHoward Hinnant            if (!__pred(*__result, *__first))
22083e519524SHoward Hinnant                *++__result = *__first;
22093e519524SHoward Hinnant        ++__result;
22103e519524SHoward Hinnant    }
22113e519524SHoward Hinnant    return __result;
22123e519524SHoward Hinnant}
22133e519524SHoward Hinnant
22143e519524SHoward Hinnanttemplate <class _InputIterator, class _OutputIterator, class _BinaryPredicate>
22154bfb9313SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
22163e519524SHoward Hinnant_OutputIterator
22173e519524SHoward Hinnantunique_copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result, _BinaryPredicate __pred)
22183e519524SHoward Hinnant{
2219ce48a113SHoward Hinnant    return _VSTD::__unique_copy<typename add_lvalue_reference<_BinaryPredicate>::type>
22203e519524SHoward Hinnant                              (__first, __last, __result, __pred,
22213e519524SHoward Hinnant                               typename iterator_traits<_InputIterator>::iterator_category(),
22223e519524SHoward Hinnant                               typename iterator_traits<_OutputIterator>::iterator_category());
22233e519524SHoward Hinnant}
22243e519524SHoward Hinnant
22253e519524SHoward Hinnanttemplate <class _InputIterator, class _OutputIterator>
22264bfb9313SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
22273e519524SHoward Hinnant_OutputIterator
22283e519524SHoward Hinnantunique_copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
22293e519524SHoward Hinnant{
22303e519524SHoward Hinnant    typedef typename iterator_traits<_InputIterator>::value_type __v;
2231ce48a113SHoward Hinnant    return _VSTD::unique_copy(__first, __last, __result, __equal_to<__v>());
22323e519524SHoward Hinnant}
22333e519524SHoward Hinnant
22343e519524SHoward Hinnant// reverse
22353e519524SHoward Hinnant
22363e519524SHoward Hinnanttemplate <class _BidirectionalIterator>
22373e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
22383e519524SHoward Hinnantvoid
22393e519524SHoward Hinnant__reverse(_BidirectionalIterator __first, _BidirectionalIterator __last, bidirectional_iterator_tag)
22403e519524SHoward Hinnant{
22413e519524SHoward Hinnant    while (__first != __last)
22423e519524SHoward Hinnant    {
22433e519524SHoward Hinnant        if (__first == --__last)
22443e519524SHoward Hinnant            break;
2245def501d1SMarshall Clow        _VSTD::iter_swap(__first, __last);
22463e519524SHoward Hinnant        ++__first;
22473e519524SHoward Hinnant    }
22483e519524SHoward Hinnant}
22493e519524SHoward Hinnant
22503e519524SHoward Hinnanttemplate <class _RandomAccessIterator>
22513e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
22523e519524SHoward Hinnantvoid
22533e519524SHoward Hinnant__reverse(_RandomAccessIterator __first, _RandomAccessIterator __last, random_access_iterator_tag)
22543e519524SHoward Hinnant{
22553e519524SHoward Hinnant    if (__first != __last)
22563e519524SHoward Hinnant        for (; __first < --__last; ++__first)
2257def501d1SMarshall Clow            _VSTD::iter_swap(__first, __last);
22583e519524SHoward Hinnant}
22593e519524SHoward Hinnant
22603e519524SHoward Hinnanttemplate <class _BidirectionalIterator>
22613e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
22623e519524SHoward Hinnantvoid
22633e519524SHoward Hinnantreverse(_BidirectionalIterator __first, _BidirectionalIterator __last)
22643e519524SHoward Hinnant{
2265ce48a113SHoward Hinnant    _VSTD::__reverse(__first, __last, typename iterator_traits<_BidirectionalIterator>::iterator_category());
22663e519524SHoward Hinnant}
22673e519524SHoward Hinnant
22683e519524SHoward Hinnant// reverse_copy
22693e519524SHoward Hinnant
22703e519524SHoward Hinnanttemplate <class _BidirectionalIterator, class _OutputIterator>
2271e8ea8296SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
22723e519524SHoward Hinnant_OutputIterator
22733e519524SHoward Hinnantreverse_copy(_BidirectionalIterator __first, _BidirectionalIterator __last, _OutputIterator __result)
22743e519524SHoward Hinnant{
22753e519524SHoward Hinnant    for (; __first != __last; ++__result)
22763e519524SHoward Hinnant        *__result = *--__last;
22773e519524SHoward Hinnant    return __result;
22783e519524SHoward Hinnant}
22793e519524SHoward Hinnant
22803e519524SHoward Hinnant// rotate
22813e519524SHoward Hinnant
22823e519524SHoward Hinnanttemplate <class _ForwardIterator>
22833e519524SHoward Hinnant_ForwardIterator
2284aca09de3SHoward Hinnant__rotate_left(_ForwardIterator __first, _ForwardIterator __last)
22853e519524SHoward Hinnant{
2286aca09de3SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
2287aca09de3SHoward Hinnant    value_type __tmp = _VSTD::move(*__first);
2288aca09de3SHoward Hinnant    _ForwardIterator __lm1 = _VSTD::move(_VSTD::next(__first), __last, __first);
2289aca09de3SHoward Hinnant    *__lm1 = _VSTD::move(__tmp);
2290aca09de3SHoward Hinnant    return __lm1;
2291aca09de3SHoward Hinnant}
2292aca09de3SHoward Hinnant
2293aca09de3SHoward Hinnanttemplate <class _BidirectionalIterator>
2294aca09de3SHoward Hinnant_BidirectionalIterator
2295aca09de3SHoward Hinnant__rotate_right(_BidirectionalIterator __first, _BidirectionalIterator __last)
2296aca09de3SHoward Hinnant{
2297aca09de3SHoward Hinnant    typedef typename iterator_traits<_BidirectionalIterator>::value_type value_type;
2298aca09de3SHoward Hinnant    _BidirectionalIterator __lm1 = _VSTD::prev(__last);
2299aca09de3SHoward Hinnant    value_type __tmp = _VSTD::move(*__lm1);
2300aca09de3SHoward Hinnant    _BidirectionalIterator __fp1 = _VSTD::move_backward(__first, __lm1, __last);
2301aca09de3SHoward Hinnant    *__first = _VSTD::move(__tmp);
2302aca09de3SHoward Hinnant    return __fp1;
2303aca09de3SHoward Hinnant}
2304aca09de3SHoward Hinnant
2305aca09de3SHoward Hinnanttemplate <class _ForwardIterator>
2306aca09de3SHoward Hinnant_ForwardIterator
2307aca09de3SHoward Hinnant__rotate_forward(_ForwardIterator __first, _ForwardIterator __middle, _ForwardIterator __last)
2308aca09de3SHoward Hinnant{
23093e519524SHoward Hinnant    _ForwardIterator __i = __middle;
23103e519524SHoward Hinnant    while (true)
23113e519524SHoward Hinnant    {
23123e519524SHoward Hinnant        swap(*__first, *__i);
23133e519524SHoward Hinnant        ++__first;
23143e519524SHoward Hinnant        if (++__i == __last)
23153e519524SHoward Hinnant            break;
23163e519524SHoward Hinnant        if (__first == __middle)
23173e519524SHoward Hinnant            __middle = __i;
23183e519524SHoward Hinnant    }
23193e519524SHoward Hinnant    _ForwardIterator __r = __first;
23203e519524SHoward Hinnant    if (__first != __middle)
23213e519524SHoward Hinnant    {
23223e519524SHoward Hinnant        __i = __middle;
23233e519524SHoward Hinnant        while (true)
23243e519524SHoward Hinnant        {
23253e519524SHoward Hinnant            swap(*__first, *__i);
23263e519524SHoward Hinnant            ++__first;
23273e519524SHoward Hinnant            if (++__i == __last)
23283e519524SHoward Hinnant            {
23293e519524SHoward Hinnant                if (__first == __middle)
23303e519524SHoward Hinnant                    break;
23313e519524SHoward Hinnant                __i = __middle;
23323e519524SHoward Hinnant            }
23333e519524SHoward Hinnant            else if (__first == __middle)
23343e519524SHoward Hinnant                __middle = __i;
23353e519524SHoward Hinnant        }
23363e519524SHoward Hinnant    }
23373e519524SHoward Hinnant    return __r;
23383e519524SHoward Hinnant}
23393e519524SHoward Hinnant
23403e519524SHoward Hinnanttemplate<typename _Integral>
23413e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
23423e519524SHoward Hinnant_Integral
234319b4035fSMarshall Clow__algo_gcd(_Integral __x, _Integral __y)
23443e519524SHoward Hinnant{
23453e519524SHoward Hinnant    do
23463e519524SHoward Hinnant    {
23473e519524SHoward Hinnant        _Integral __t = __x % __y;
23483e519524SHoward Hinnant        __x = __y;
23493e519524SHoward Hinnant        __y = __t;
23503e519524SHoward Hinnant    } while (__y);
23513e519524SHoward Hinnant    return __x;
23523e519524SHoward Hinnant}
23533e519524SHoward Hinnant
23543e519524SHoward Hinnanttemplate<typename _RandomAccessIterator>
23553e519524SHoward Hinnant_RandomAccessIterator
2356aca09de3SHoward Hinnant__rotate_gcd(_RandomAccessIterator __first, _RandomAccessIterator __middle, _RandomAccessIterator __last)
23573e519524SHoward Hinnant{
23583e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
23593e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
23603e519524SHoward Hinnant
23613e519524SHoward Hinnant    const difference_type __m1 = __middle - __first;
23623e519524SHoward Hinnant    const difference_type __m2 = __last - __middle;
23633e519524SHoward Hinnant    if (__m1 == __m2)
23643e519524SHoward Hinnant    {
2365ce48a113SHoward Hinnant        _VSTD::swap_ranges(__first, __middle, __middle);
23663e519524SHoward Hinnant        return __middle;
23673e519524SHoward Hinnant    }
236819b4035fSMarshall Clow    const difference_type __g = _VSTD::__algo_gcd(__m1, __m2);
23693e519524SHoward Hinnant    for (_RandomAccessIterator __p = __first + __g; __p != __first;)
23703e519524SHoward Hinnant    {
2371aca09de3SHoward Hinnant        value_type __t(_VSTD::move(*--__p));
23723e519524SHoward Hinnant        _RandomAccessIterator __p1 = __p;
23733e519524SHoward Hinnant        _RandomAccessIterator __p2 = __p1 + __m1;
23743e519524SHoward Hinnant        do
23753e519524SHoward Hinnant        {
2376aca09de3SHoward Hinnant            *__p1 = _VSTD::move(*__p2);
23773e519524SHoward Hinnant            __p1 = __p2;
23783e519524SHoward Hinnant            const difference_type __d = __last - __p2;
23793e519524SHoward Hinnant            if (__m1 < __d)
23803e519524SHoward Hinnant                __p2 += __m1;
23813e519524SHoward Hinnant            else
23823e519524SHoward Hinnant                __p2 = __first + (__m1 - __d);
23833e519524SHoward Hinnant        } while (__p2 != __p);
2384aca09de3SHoward Hinnant        *__p1 = _VSTD::move(__t);
23853e519524SHoward Hinnant    }
23863e519524SHoward Hinnant    return __first + __m2;
23873e519524SHoward Hinnant}
23883e519524SHoward Hinnant
23893e519524SHoward Hinnanttemplate <class _ForwardIterator>
23903e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
23913e519524SHoward Hinnant_ForwardIterator
2392aca09de3SHoward Hinnant__rotate(_ForwardIterator __first, _ForwardIterator __middle, _ForwardIterator __last,
2393aca09de3SHoward Hinnant         _VSTD::forward_iterator_tag)
2394aca09de3SHoward Hinnant{
2395aca09de3SHoward Hinnant    typedef typename _VSTD::iterator_traits<_ForwardIterator>::value_type value_type;
2396aca09de3SHoward Hinnant    if (_VSTD::is_trivially_move_assignable<value_type>::value)
2397aca09de3SHoward Hinnant    {
2398aca09de3SHoward Hinnant        if (_VSTD::next(__first) == __middle)
2399aca09de3SHoward Hinnant            return _VSTD::__rotate_left(__first, __last);
2400aca09de3SHoward Hinnant    }
2401aca09de3SHoward Hinnant    return _VSTD::__rotate_forward(__first, __middle, __last);
2402aca09de3SHoward Hinnant}
2403aca09de3SHoward Hinnant
2404aca09de3SHoward Hinnanttemplate <class _BidirectionalIterator>
2405aca09de3SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
2406aca09de3SHoward Hinnant_BidirectionalIterator
2407aca09de3SHoward Hinnant__rotate(_BidirectionalIterator __first, _BidirectionalIterator __middle, _BidirectionalIterator __last,
2408aca09de3SHoward Hinnant         _VSTD::bidirectional_iterator_tag)
2409aca09de3SHoward Hinnant{
2410aca09de3SHoward Hinnant    typedef typename _VSTD::iterator_traits<_BidirectionalIterator>::value_type value_type;
2411aca09de3SHoward Hinnant    if (_VSTD::is_trivially_move_assignable<value_type>::value)
2412aca09de3SHoward Hinnant    {
2413aca09de3SHoward Hinnant        if (_VSTD::next(__first) == __middle)
2414aca09de3SHoward Hinnant            return _VSTD::__rotate_left(__first, __last);
2415aca09de3SHoward Hinnant        if (_VSTD::next(__middle) == __last)
2416aca09de3SHoward Hinnant            return _VSTD::__rotate_right(__first, __last);
2417aca09de3SHoward Hinnant    }
2418aca09de3SHoward Hinnant    return _VSTD::__rotate_forward(__first, __middle, __last);
2419aca09de3SHoward Hinnant}
2420aca09de3SHoward Hinnant
2421aca09de3SHoward Hinnanttemplate <class _RandomAccessIterator>
2422aca09de3SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
2423aca09de3SHoward Hinnant_RandomAccessIterator
2424aca09de3SHoward Hinnant__rotate(_RandomAccessIterator __first, _RandomAccessIterator __middle, _RandomAccessIterator __last,
2425aca09de3SHoward Hinnant         _VSTD::random_access_iterator_tag)
2426aca09de3SHoward Hinnant{
2427aca09de3SHoward Hinnant    typedef typename _VSTD::iterator_traits<_RandomAccessIterator>::value_type value_type;
2428aca09de3SHoward Hinnant    if (_VSTD::is_trivially_move_assignable<value_type>::value)
2429aca09de3SHoward Hinnant    {
2430aca09de3SHoward Hinnant        if (_VSTD::next(__first) == __middle)
2431aca09de3SHoward Hinnant            return _VSTD::__rotate_left(__first, __last);
2432aca09de3SHoward Hinnant        if (_VSTD::next(__middle) == __last)
2433aca09de3SHoward Hinnant            return _VSTD::__rotate_right(__first, __last);
2434aca09de3SHoward Hinnant        return _VSTD::__rotate_gcd(__first, __middle, __last);
2435aca09de3SHoward Hinnant    }
2436aca09de3SHoward Hinnant    return _VSTD::__rotate_forward(__first, __middle, __last);
2437aca09de3SHoward Hinnant}
2438aca09de3SHoward Hinnant
2439aca09de3SHoward Hinnanttemplate <class _ForwardIterator>
2440aca09de3SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
2441aca09de3SHoward Hinnant_ForwardIterator
24423e519524SHoward Hinnantrotate(_ForwardIterator __first, _ForwardIterator __middle, _ForwardIterator __last)
24433e519524SHoward Hinnant{
2444aca09de3SHoward Hinnant    if (__first == __middle)
2445aca09de3SHoward Hinnant        return __last;
2446aca09de3SHoward Hinnant    if (__middle == __last)
2447aca09de3SHoward Hinnant        return __first;
2448ce48a113SHoward Hinnant    return _VSTD::__rotate(__first, __middle, __last,
2449aca09de3SHoward Hinnant                           typename _VSTD::iterator_traits<_ForwardIterator>::iterator_category());
24503e519524SHoward Hinnant}
24513e519524SHoward Hinnant
24523e519524SHoward Hinnant// rotate_copy
24533e519524SHoward Hinnant
24543e519524SHoward Hinnanttemplate <class _ForwardIterator, class _OutputIterator>
24553e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
24563e519524SHoward Hinnant_OutputIterator
24573e519524SHoward Hinnantrotate_copy(_ForwardIterator __first, _ForwardIterator __middle, _ForwardIterator __last, _OutputIterator __result)
24583e519524SHoward Hinnant{
2459ce48a113SHoward Hinnant    return _VSTD::copy(__first, __middle, _VSTD::copy(__middle, __last, __result));
24603e519524SHoward Hinnant}
24613e519524SHoward Hinnant
24623e519524SHoward Hinnant// min_element
24633e519524SHoward Hinnant
24643e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Compare>
2465*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
2466*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
24673e519524SHoward Hinnant_ForwardIterator
24680b0671aeSMarshall Clowmin_element(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp)
24693e519524SHoward Hinnant{
2470a60d7facSEric Fiselier    static_assert(__is_forward_iterator<_ForwardIterator>::value,
2471a60d7facSEric Fiselier        "std::min_element requires a ForwardIterator");
24723e519524SHoward Hinnant    if (__first != __last)
24733e519524SHoward Hinnant    {
24743e519524SHoward Hinnant        _ForwardIterator __i = __first;
24753e519524SHoward Hinnant        while (++__i != __last)
24763e519524SHoward Hinnant            if (__comp(*__i, *__first))
24773e519524SHoward Hinnant                __first = __i;
24783e519524SHoward Hinnant    }
24793e519524SHoward Hinnant    return __first;
24803e519524SHoward Hinnant}
24813e519524SHoward Hinnant
24823e519524SHoward Hinnanttemplate <class _ForwardIterator>
2483*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
2484*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
24853e519524SHoward Hinnant_ForwardIterator
24863e519524SHoward Hinnantmin_element(_ForwardIterator __first, _ForwardIterator __last)
24873e519524SHoward Hinnant{
24880b0671aeSMarshall Clow    return _VSTD::min_element(__first, __last,
24894eb27b79SHoward Hinnant              __less<typename iterator_traits<_ForwardIterator>::value_type>());
24904eb27b79SHoward Hinnant}
24914eb27b79SHoward Hinnant
24924eb27b79SHoward Hinnant// min
24934eb27b79SHoward Hinnant
24944eb27b79SHoward Hinnanttemplate <class _Tp, class _Compare>
2495*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
2496*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
24974eb27b79SHoward Hinnantconst _Tp&
24984eb27b79SHoward Hinnantmin(const _Tp& __a, const _Tp& __b, _Compare __comp)
24994eb27b79SHoward Hinnant{
25004eb27b79SHoward Hinnant    return __comp(__b, __a) ? __b : __a;
25014eb27b79SHoward Hinnant}
25024eb27b79SHoward Hinnant
25034eb27b79SHoward Hinnanttemplate <class _Tp>
2504*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
2505*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
25064eb27b79SHoward Hinnantconst _Tp&
25074eb27b79SHoward Hinnantmin(const _Tp& __a, const _Tp& __b)
25084eb27b79SHoward Hinnant{
2509ce48a113SHoward Hinnant    return _VSTD::min(__a, __b, __less<_Tp>());
25104eb27b79SHoward Hinnant}
25114eb27b79SHoward Hinnant
2512ddda456aSEric Fiselier#ifndef _LIBCPP_CXX03_LANG
251354976f26SHoward Hinnant
25144eb27b79SHoward Hinnanttemplate<class _Tp, class _Compare>
2515*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
2516*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
25174eb27b79SHoward Hinnant_Tp
25184eb27b79SHoward Hinnantmin(initializer_list<_Tp> __t, _Compare __comp)
25194eb27b79SHoward Hinnant{
25200b0671aeSMarshall Clow    return *_VSTD::min_element(__t.begin(), __t.end(), __comp);
25214eb27b79SHoward Hinnant}
25224eb27b79SHoward Hinnant
25234eb27b79SHoward Hinnanttemplate<class _Tp>
2524*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
2525*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
25264eb27b79SHoward Hinnant_Tp
25274eb27b79SHoward Hinnantmin(initializer_list<_Tp> __t)
25284eb27b79SHoward Hinnant{
25290b0671aeSMarshall Clow    return *_VSTD::min_element(__t.begin(), __t.end(), __less<_Tp>());
25303e519524SHoward Hinnant}
25313e519524SHoward Hinnant
2532ddda456aSEric Fiselier#endif  // _LIBCPP_CXX03_LANG
253354976f26SHoward Hinnant
25343e519524SHoward Hinnant// max_element
25353e519524SHoward Hinnant
25363e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Compare>
2537*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
2538*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
25393e519524SHoward Hinnant_ForwardIterator
25400b0671aeSMarshall Clowmax_element(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp)
25413e519524SHoward Hinnant{
2542a60d7facSEric Fiselier    static_assert(__is_forward_iterator<_ForwardIterator>::value,
2543a60d7facSEric Fiselier        "std::max_element requires a ForwardIterator");
25443e519524SHoward Hinnant    if (__first != __last)
25453e519524SHoward Hinnant    {
25463e519524SHoward Hinnant        _ForwardIterator __i = __first;
25473e519524SHoward Hinnant        while (++__i != __last)
25483e519524SHoward Hinnant            if (__comp(*__first, *__i))
25493e519524SHoward Hinnant                __first = __i;
25503e519524SHoward Hinnant    }
25513e519524SHoward Hinnant    return __first;
25523e519524SHoward Hinnant}
25533e519524SHoward Hinnant
25549d67c6d5SMarshall Clow
25553e519524SHoward Hinnanttemplate <class _ForwardIterator>
2556*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
2557*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
25583e519524SHoward Hinnant_ForwardIterator
25593e519524SHoward Hinnantmax_element(_ForwardIterator __first, _ForwardIterator __last)
25603e519524SHoward Hinnant{
25610b0671aeSMarshall Clow    return _VSTD::max_element(__first, __last,
25624eb27b79SHoward Hinnant              __less<typename iterator_traits<_ForwardIterator>::value_type>());
25634eb27b79SHoward Hinnant}
25644eb27b79SHoward Hinnant
25654eb27b79SHoward Hinnant// max
25664eb27b79SHoward Hinnant
25674eb27b79SHoward Hinnanttemplate <class _Tp, class _Compare>
2568*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
2569*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
25704eb27b79SHoward Hinnantconst _Tp&
25714eb27b79SHoward Hinnantmax(const _Tp& __a, const _Tp& __b, _Compare __comp)
25724eb27b79SHoward Hinnant{
25734eb27b79SHoward Hinnant    return __comp(__a, __b) ? __b : __a;
25744eb27b79SHoward Hinnant}
25754eb27b79SHoward Hinnant
25764eb27b79SHoward Hinnanttemplate <class _Tp>
2577*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
2578*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
25794eb27b79SHoward Hinnantconst _Tp&
25804eb27b79SHoward Hinnantmax(const _Tp& __a, const _Tp& __b)
25814eb27b79SHoward Hinnant{
2582ce48a113SHoward Hinnant    return _VSTD::max(__a, __b, __less<_Tp>());
25834eb27b79SHoward Hinnant}
25844eb27b79SHoward Hinnant
2585ddda456aSEric Fiselier#ifndef _LIBCPP_CXX03_LANG
258654976f26SHoward Hinnant
25874eb27b79SHoward Hinnanttemplate<class _Tp, class _Compare>
2588*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
2589*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
25904eb27b79SHoward Hinnant_Tp
25914eb27b79SHoward Hinnantmax(initializer_list<_Tp> __t, _Compare __comp)
25924eb27b79SHoward Hinnant{
25930b0671aeSMarshall Clow    return *_VSTD::max_element(__t.begin(), __t.end(), __comp);
25944eb27b79SHoward Hinnant}
25954eb27b79SHoward Hinnant
25964eb27b79SHoward Hinnanttemplate<class _Tp>
2597*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
2598*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
25994eb27b79SHoward Hinnant_Tp
26004eb27b79SHoward Hinnantmax(initializer_list<_Tp> __t)
26014eb27b79SHoward Hinnant{
26020b0671aeSMarshall Clow    return *_VSTD::max_element(__t.begin(), __t.end(), __less<_Tp>());
26033e519524SHoward Hinnant}
26043e519524SHoward Hinnant
2605ddda456aSEric Fiselier#endif  // _LIBCPP_CXX03_LANG
260654976f26SHoward Hinnant
2607146c14acSMarshall Clow#if _LIBCPP_STD_VER > 14
2608146c14acSMarshall Clow// clamp
2609146c14acSMarshall Clowtemplate<class _Tp, class _Compare>
2610*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
2611*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
2612146c14acSMarshall Clowconst _Tp&
2613146c14acSMarshall Clowclamp(const _Tp& __v, const _Tp& __lo, const _Tp& __hi, _Compare __comp)
2614146c14acSMarshall Clow{
2615146c14acSMarshall Clow    _LIBCPP_ASSERT(!__comp(__hi, __lo), "Bad bounds passed to std::clamp");
2616146c14acSMarshall Clow    return __comp(__v, __lo) ? __lo : __comp(__hi, __v) ? __hi : __v;
2617146c14acSMarshall Clow
2618146c14acSMarshall Clow}
2619146c14acSMarshall Clow
2620146c14acSMarshall Clowtemplate<class _Tp>
2621*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
2622*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
2623146c14acSMarshall Clowconst _Tp&
2624146c14acSMarshall Clowclamp(const _Tp& __v, const _Tp& __lo, const _Tp& __hi)
2625146c14acSMarshall Clow{
2626146c14acSMarshall Clow    return _VSTD::clamp(__v, __lo, __hi, __less<_Tp>());
2627146c14acSMarshall Clow}
2628146c14acSMarshall Clow#endif
2629146c14acSMarshall Clow
26303e519524SHoward Hinnant// minmax_element
26313e519524SHoward Hinnant
26323e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Compare>
2633*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT _LIBCPP_CONSTEXPR_AFTER_CXX11
26343e519524SHoward Hinnantstd::pair<_ForwardIterator, _ForwardIterator>
26353e519524SHoward Hinnantminmax_element(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp)
26363e519524SHoward Hinnant{
2637a60d7facSEric Fiselier  static_assert(__is_forward_iterator<_ForwardIterator>::value,
2638a60d7facSEric Fiselier        "std::minmax_element requires a ForwardIterator");
26393e519524SHoward Hinnant  std::pair<_ForwardIterator, _ForwardIterator> __result(__first, __first);
26403e519524SHoward Hinnant  if (__first != __last)
26413e519524SHoward Hinnant  {
26423e519524SHoward Hinnant      if (++__first != __last)
26433e519524SHoward Hinnant      {
26443e519524SHoward Hinnant          if (__comp(*__first, *__result.first))
26453e519524SHoward Hinnant              __result.first = __first;
26463e519524SHoward Hinnant          else
26473e519524SHoward Hinnant              __result.second = __first;
26483e519524SHoward Hinnant          while (++__first != __last)
26493e519524SHoward Hinnant          {
26503e519524SHoward Hinnant              _ForwardIterator __i = __first;
26513e519524SHoward Hinnant              if (++__first == __last)
26523e519524SHoward Hinnant              {
26533e519524SHoward Hinnant                  if (__comp(*__i, *__result.first))
26543e519524SHoward Hinnant                      __result.first = __i;
26553e519524SHoward Hinnant                  else if (!__comp(*__i, *__result.second))
26563e519524SHoward Hinnant                      __result.second = __i;
26573e519524SHoward Hinnant                  break;
26583e519524SHoward Hinnant              }
26593e519524SHoward Hinnant              else
26603e519524SHoward Hinnant              {
26613e519524SHoward Hinnant                  if (__comp(*__first, *__i))
26623e519524SHoward Hinnant                  {
26633e519524SHoward Hinnant                      if (__comp(*__first, *__result.first))
26643e519524SHoward Hinnant                          __result.first = __first;
26653e519524SHoward Hinnant                      if (!__comp(*__i, *__result.second))
26663e519524SHoward Hinnant                          __result.second = __i;
26673e519524SHoward Hinnant                  }
26683e519524SHoward Hinnant                  else
26693e519524SHoward Hinnant                  {
26703e519524SHoward Hinnant                      if (__comp(*__i, *__result.first))
26713e519524SHoward Hinnant                          __result.first = __i;
26723e519524SHoward Hinnant                      if (!__comp(*__first, *__result.second))
26733e519524SHoward Hinnant                          __result.second = __first;
26743e519524SHoward Hinnant                  }
26753e519524SHoward Hinnant              }
26763e519524SHoward Hinnant          }
26773e519524SHoward Hinnant      }
26783e519524SHoward Hinnant  }
26793e519524SHoward Hinnant  return __result;
26803e519524SHoward Hinnant}
26813e519524SHoward Hinnant
26823e519524SHoward Hinnanttemplate <class _ForwardIterator>
2683*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
2684*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
26853e519524SHoward Hinnantstd::pair<_ForwardIterator, _ForwardIterator>
26863e519524SHoward Hinnantminmax_element(_ForwardIterator __first, _ForwardIterator __last)
26873e519524SHoward Hinnant{
26889d67c6d5SMarshall Clow    return _VSTD::minmax_element(__first, __last,
26899d67c6d5SMarshall Clow              __less<typename iterator_traits<_ForwardIterator>::value_type>());
26903e519524SHoward Hinnant}
26913e519524SHoward Hinnant
26924eb27b79SHoward Hinnant// minmax
26934eb27b79SHoward Hinnant
26944eb27b79SHoward Hinnanttemplate<class _Tp, class _Compare>
2695*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
2696*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
26974eb27b79SHoward Hinnantpair<const _Tp&, const _Tp&>
26984eb27b79SHoward Hinnantminmax(const _Tp& __a, const _Tp& __b, _Compare __comp)
26994eb27b79SHoward Hinnant{
27004eb27b79SHoward Hinnant    return __comp(__b, __a) ? pair<const _Tp&, const _Tp&>(__b, __a) :
27014eb27b79SHoward Hinnant                              pair<const _Tp&, const _Tp&>(__a, __b);
27024eb27b79SHoward Hinnant}
27034eb27b79SHoward Hinnant
27044eb27b79SHoward Hinnanttemplate<class _Tp>
2705*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
2706*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
27074eb27b79SHoward Hinnantpair<const _Tp&, const _Tp&>
27084eb27b79SHoward Hinnantminmax(const _Tp& __a, const _Tp& __b)
27094eb27b79SHoward Hinnant{
2710ce48a113SHoward Hinnant    return _VSTD::minmax(__a, __b, __less<_Tp>());
27114eb27b79SHoward Hinnant}
27124eb27b79SHoward Hinnant
2713ddda456aSEric Fiselier#ifndef _LIBCPP_CXX03_LANG
271454976f26SHoward Hinnant
27154eb27b79SHoward Hinnanttemplate<class _Tp, class _Compare>
2716*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
2717*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
27184eb27b79SHoward Hinnantpair<_Tp, _Tp>
27194eb27b79SHoward Hinnantminmax(initializer_list<_Tp> __t, _Compare __comp)
27204eb27b79SHoward Hinnant{
27219d67c6d5SMarshall Clow    typedef typename initializer_list<_Tp>::const_iterator _Iter;
27229d67c6d5SMarshall Clow    _Iter __first = __t.begin();
27239d67c6d5SMarshall Clow    _Iter __last  = __t.end();
27249d67c6d5SMarshall Clow    std::pair<_Tp, _Tp> __result(*__first, *__first);
27259d67c6d5SMarshall Clow
27269d67c6d5SMarshall Clow    ++__first;
27279d67c6d5SMarshall Clow    if (__t.size() % 2 == 0)
27289d67c6d5SMarshall Clow    {
27299d67c6d5SMarshall Clow        if (__comp(*__first,  __result.first))
27309d67c6d5SMarshall Clow            __result.first  = *__first;
27319d67c6d5SMarshall Clow        else
27329d67c6d5SMarshall Clow            __result.second = *__first;
27339d67c6d5SMarshall Clow        ++__first;
27349d67c6d5SMarshall Clow    }
27359d67c6d5SMarshall Clow
27369d67c6d5SMarshall Clow    while (__first != __last)
27379d67c6d5SMarshall Clow    {
27389d67c6d5SMarshall Clow        _Tp __prev = *__first++;
2739002144f6SMarshall Clow        if (__comp(*__first, __prev)) {
2740002144f6SMarshall Clow            if ( __comp(*__first, __result.first)) __result.first  = *__first;
2741002144f6SMarshall Clow            if (!__comp(__prev, __result.second))  __result.second = __prev;
27429d67c6d5SMarshall Clow            }
27439d67c6d5SMarshall Clow        else {
2744002144f6SMarshall Clow            if ( __comp(__prev, __result.first))    __result.first  = __prev;
2745002144f6SMarshall Clow            if (!__comp(*__first, __result.second)) __result.second = *__first;
27469d67c6d5SMarshall Clow            }
27479d67c6d5SMarshall Clow
27489d67c6d5SMarshall Clow        __first++;
27499d67c6d5SMarshall Clow    }
27509d67c6d5SMarshall Clow    return __result;
27519d67c6d5SMarshall Clow}
27529d67c6d5SMarshall Clow
27539d67c6d5SMarshall Clowtemplate<class _Tp>
2754*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
2755*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
27569d67c6d5SMarshall Clowpair<_Tp, _Tp>
27579d67c6d5SMarshall Clowminmax(initializer_list<_Tp> __t)
27589d67c6d5SMarshall Clow{
27599d67c6d5SMarshall Clow    return _VSTD::minmax(__t, __less<_Tp>());
27604eb27b79SHoward Hinnant}
27614eb27b79SHoward Hinnant
2762ddda456aSEric Fiselier#endif  // _LIBCPP_CXX03_LANG
276354976f26SHoward Hinnant
27643e519524SHoward Hinnant// random_shuffle
27653e519524SHoward Hinnant
2766f9d540b0SHoward Hinnant// __independent_bits_engine
2767f9d540b0SHoward Hinnant
2768c003db1fSHoward Hinnanttemplate <unsigned long long _Xp, size_t _Rp>
2769f9d540b0SHoward Hinnantstruct __log2_imp
27703e519524SHoward Hinnant{
2771c003db1fSHoward Hinnant    static const size_t value = _Xp & ((unsigned long long)(1) << _Rp) ? _Rp
2772c003db1fSHoward Hinnant                                           : __log2_imp<_Xp, _Rp - 1>::value;
27733e519524SHoward Hinnant};
27743e519524SHoward Hinnant
2775c003db1fSHoward Hinnanttemplate <unsigned long long _Xp>
2776c003db1fSHoward Hinnantstruct __log2_imp<_Xp, 0>
27773e519524SHoward Hinnant{
2778f9d540b0SHoward Hinnant    static const size_t value = 0;
27793e519524SHoward Hinnant};
27803e519524SHoward Hinnant
2781c003db1fSHoward Hinnanttemplate <size_t _Rp>
2782c003db1fSHoward Hinnantstruct __log2_imp<0, _Rp>
27833e519524SHoward Hinnant{
2784c003db1fSHoward Hinnant    static const size_t value = _Rp + 1;
27853e519524SHoward Hinnant};
27863e519524SHoward Hinnant
278789918caaSEric Fiseliertemplate <class _UIntType, _UIntType _Xp>
2788f9d540b0SHoward Hinnantstruct __log2
27893e519524SHoward Hinnant{
2790c003db1fSHoward Hinnant    static const size_t value = __log2_imp<_Xp,
279189918caaSEric Fiselier                                         sizeof(_UIntType) * __CHAR_BIT__ - 1>::value;
27923e519524SHoward Hinnant};
27933e519524SHoward Hinnant
2794f9d540b0SHoward Hinnanttemplate<class _Engine, class _UIntType>
2795f9d540b0SHoward Hinnantclass __independent_bits_engine
27963e519524SHoward Hinnant{
2797f9d540b0SHoward Hinnantpublic:
2798f9d540b0SHoward Hinnant    // types
2799f9d540b0SHoward Hinnant    typedef _UIntType result_type;
2800f9d540b0SHoward Hinnant
2801f9d540b0SHoward Hinnantprivate:
2802f9d540b0SHoward Hinnant    typedef typename _Engine::result_type _Engine_result_type;
2803f9d540b0SHoward Hinnant    typedef typename conditional
2804f9d540b0SHoward Hinnant        <
2805f9d540b0SHoward Hinnant            sizeof(_Engine_result_type) <= sizeof(result_type),
2806f9d540b0SHoward Hinnant                result_type,
2807f9d540b0SHoward Hinnant                _Engine_result_type
2808f9d540b0SHoward Hinnant        >::type _Working_result_type;
2809f9d540b0SHoward Hinnant
2810f9d540b0SHoward Hinnant    _Engine& __e_;
2811f9d540b0SHoward Hinnant    size_t __w_;
2812f9d540b0SHoward Hinnant    size_t __w0_;
2813f9d540b0SHoward Hinnant    size_t __n_;
2814f9d540b0SHoward Hinnant    size_t __n0_;
2815f9d540b0SHoward Hinnant    _Working_result_type __y0_;
2816f9d540b0SHoward Hinnant    _Working_result_type __y1_;
2817f9d540b0SHoward Hinnant    _Engine_result_type __mask0_;
2818f9d540b0SHoward Hinnant    _Engine_result_type __mask1_;
2819f9d540b0SHoward Hinnant
2820ddda456aSEric Fiselier#ifdef _LIBCPP_CXX03_LANG
2821c003db1fSHoward Hinnant    static const _Working_result_type _Rp = _Engine::_Max - _Engine::_Min
2822f9d540b0SHoward Hinnant                                          + _Working_result_type(1);
2823e386b7b3SHoward Hinnant#else
2824e386b7b3SHoward Hinnant    static _LIBCPP_CONSTEXPR const _Working_result_type _Rp = _Engine::max() - _Engine::min()
2825e386b7b3SHoward Hinnant                                                      + _Working_result_type(1);
2826e386b7b3SHoward Hinnant#endif
2827e386b7b3SHoward Hinnant    static _LIBCPP_CONSTEXPR const size_t __m = __log2<_Working_result_type, _Rp>::value;
2828e386b7b3SHoward Hinnant    static _LIBCPP_CONSTEXPR const size_t _WDt = numeric_limits<_Working_result_type>::digits;
2829e386b7b3SHoward Hinnant    static _LIBCPP_CONSTEXPR const size_t _EDt = numeric_limits<_Engine_result_type>::digits;
2830f9d540b0SHoward Hinnant
2831f9d540b0SHoward Hinnantpublic:
2832f9d540b0SHoward Hinnant    // constructors and seeding functions
2833f9d540b0SHoward Hinnant    __independent_bits_engine(_Engine& __e, size_t __w);
2834f9d540b0SHoward Hinnant
2835f9d540b0SHoward Hinnant    // generating functions
2836c003db1fSHoward Hinnant    result_type operator()() {return __eval(integral_constant<bool, _Rp != 0>());}
2837f9d540b0SHoward Hinnant
2838f9d540b0SHoward Hinnantprivate:
283908bba64aSMarshall Clow    result_type __eval(false_type);
284008bba64aSMarshall Clow    result_type __eval(true_type);
2841f9d540b0SHoward Hinnant};
2842f9d540b0SHoward Hinnant
2843f9d540b0SHoward Hinnanttemplate<class _Engine, class _UIntType>
2844f9d540b0SHoward Hinnant__independent_bits_engine<_Engine, _UIntType>
2845f9d540b0SHoward Hinnant    ::__independent_bits_engine(_Engine& __e, size_t __w)
2846f9d540b0SHoward Hinnant        : __e_(__e),
2847f9d540b0SHoward Hinnant          __w_(__w)
2848f9d540b0SHoward Hinnant{
2849f9d540b0SHoward Hinnant    __n_ = __w_ / __m + (__w_ % __m != 0);
2850f9d540b0SHoward Hinnant    __w0_ = __w_ / __n_;
2851c003db1fSHoward Hinnant    if (_Rp == 0)
2852c003db1fSHoward Hinnant        __y0_ = _Rp;
2853f9d540b0SHoward Hinnant    else if (__w0_ < _WDt)
2854c003db1fSHoward Hinnant        __y0_ = (_Rp >> __w0_) << __w0_;
2855f9d540b0SHoward Hinnant    else
2856f9d540b0SHoward Hinnant        __y0_ = 0;
2857c003db1fSHoward Hinnant    if (_Rp - __y0_ > __y0_ / __n_)
2858f9d540b0SHoward Hinnant    {
2859f9d540b0SHoward Hinnant        ++__n_;
2860f9d540b0SHoward Hinnant        __w0_ = __w_ / __n_;
2861f9d540b0SHoward Hinnant        if (__w0_ < _WDt)
2862c003db1fSHoward Hinnant            __y0_ = (_Rp >> __w0_) << __w0_;
2863f9d540b0SHoward Hinnant        else
2864f9d540b0SHoward Hinnant            __y0_ = 0;
2865f9d540b0SHoward Hinnant    }
2866f9d540b0SHoward Hinnant    __n0_ = __n_ - __w_ % __n_;
2867f9d540b0SHoward Hinnant    if (__w0_ < _WDt - 1)
2868c003db1fSHoward Hinnant        __y1_ = (_Rp >> (__w0_ + 1)) << (__w0_ + 1);
2869f9d540b0SHoward Hinnant    else
2870f9d540b0SHoward Hinnant        __y1_ = 0;
2871f9d540b0SHoward Hinnant    __mask0_ = __w0_ > 0 ? _Engine_result_type(~0) >> (_EDt - __w0_) :
2872f9d540b0SHoward Hinnant                          _Engine_result_type(0);
2873f9d540b0SHoward Hinnant    __mask1_ = __w0_ < _EDt - 1 ?
2874f9d540b0SHoward Hinnant                               _Engine_result_type(~0) >> (_EDt - (__w0_ + 1)) :
2875f9d540b0SHoward Hinnant                               _Engine_result_type(~0);
28763e519524SHoward Hinnant}
28773e519524SHoward Hinnant
2878f9d540b0SHoward Hinnanttemplate<class _Engine, class _UIntType>
2879f9d540b0SHoward Hinnantinline
2880f9d540b0SHoward Hinnant_UIntType
288108bba64aSMarshall Clow__independent_bits_engine<_Engine, _UIntType>::__eval(false_type)
28823e519524SHoward Hinnant{
2883f9d540b0SHoward Hinnant    return static_cast<result_type>(__e_() & __mask0_);
28843e519524SHoward Hinnant}
28853e519524SHoward Hinnant
2886f9d540b0SHoward Hinnanttemplate<class _Engine, class _UIntType>
2887f9d540b0SHoward Hinnant_UIntType
288808bba64aSMarshall Clow__independent_bits_engine<_Engine, _UIntType>::__eval(true_type)
28893e519524SHoward Hinnant{
28905beb2c3aSMarshall Clow    const size_t _WRt = numeric_limits<result_type>::digits;
2891c003db1fSHoward Hinnant    result_type _Sp = 0;
2892f9d540b0SHoward Hinnant    for (size_t __k = 0; __k < __n0_; ++__k)
2893f9d540b0SHoward Hinnant    {
2894f9d540b0SHoward Hinnant        _Engine_result_type __u;
28953e519524SHoward Hinnant        do
2896f9d540b0SHoward Hinnant        {
2897f9d540b0SHoward Hinnant            __u = __e_() - _Engine::min();
2898f9d540b0SHoward Hinnant        } while (__u >= __y0_);
28995beb2c3aSMarshall Clow        if (__w0_ < _WRt)
2900c003db1fSHoward Hinnant            _Sp <<= __w0_;
2901f9d540b0SHoward Hinnant        else
2902c003db1fSHoward Hinnant            _Sp = 0;
2903c003db1fSHoward Hinnant        _Sp += __u & __mask0_;
2904f9d540b0SHoward Hinnant    }
2905f9d540b0SHoward Hinnant    for (size_t __k = __n0_; __k < __n_; ++__k)
2906f9d540b0SHoward Hinnant    {
2907f9d540b0SHoward Hinnant        _Engine_result_type __u;
2908f9d540b0SHoward Hinnant        do
2909f9d540b0SHoward Hinnant        {
2910f9d540b0SHoward Hinnant            __u = __e_() - _Engine::min();
2911f9d540b0SHoward Hinnant        } while (__u >= __y1_);
29125beb2c3aSMarshall Clow        if (__w0_ < _WRt - 1)
2913c003db1fSHoward Hinnant            _Sp <<= __w0_ + 1;
2914f9d540b0SHoward Hinnant        else
2915c003db1fSHoward Hinnant            _Sp = 0;
2916c003db1fSHoward Hinnant        _Sp += __u & __mask1_;
2917f9d540b0SHoward Hinnant    }
2918c003db1fSHoward Hinnant    return _Sp;
29193e519524SHoward Hinnant}
29203e519524SHoward Hinnant
2921f9d540b0SHoward Hinnant// uniform_int_distribution
29223e519524SHoward Hinnant
2923f9d540b0SHoward Hinnanttemplate<class _IntType = int>
2924f9d540b0SHoward Hinnantclass uniform_int_distribution
29253e519524SHoward Hinnant{
2926f9d540b0SHoward Hinnantpublic:
2927f9d540b0SHoward Hinnant    // types
2928f9d540b0SHoward Hinnant    typedef _IntType result_type;
2929f9d540b0SHoward Hinnant
2930f9d540b0SHoward Hinnant    class param_type
2931f9d540b0SHoward Hinnant    {
2932f9d540b0SHoward Hinnant        result_type __a_;
2933f9d540b0SHoward Hinnant        result_type __b_;
2934f9d540b0SHoward Hinnant    public:
2935f9d540b0SHoward Hinnant        typedef uniform_int_distribution distribution_type;
2936f9d540b0SHoward Hinnant
2937f9d540b0SHoward Hinnant        explicit param_type(result_type __a = 0,
2938f9d540b0SHoward Hinnant                            result_type __b = numeric_limits<result_type>::max())
2939f9d540b0SHoward Hinnant            : __a_(__a), __b_(__b) {}
2940f9d540b0SHoward Hinnant
2941f9d540b0SHoward Hinnant        result_type a() const {return __a_;}
2942f9d540b0SHoward Hinnant        result_type b() const {return __b_;}
2943f9d540b0SHoward Hinnant
2944f9d540b0SHoward Hinnant        friend bool operator==(const param_type& __x, const param_type& __y)
2945f9d540b0SHoward Hinnant            {return __x.__a_ == __y.__a_ && __x.__b_ == __y.__b_;}
2946f9d540b0SHoward Hinnant        friend bool operator!=(const param_type& __x, const param_type& __y)
2947f9d540b0SHoward Hinnant            {return !(__x == __y);}
29483e519524SHoward Hinnant    };
29493e519524SHoward Hinnant
2950f9d540b0SHoward Hinnantprivate:
2951f9d540b0SHoward Hinnant    param_type __p_;
29523e519524SHoward Hinnant
2953f9d540b0SHoward Hinnantpublic:
2954f9d540b0SHoward Hinnant    // constructors and reset functions
2955f9d540b0SHoward Hinnant    explicit uniform_int_distribution(result_type __a = 0,
2956f9d540b0SHoward Hinnant                                      result_type __b = numeric_limits<result_type>::max())
2957f9d540b0SHoward Hinnant        : __p_(param_type(__a, __b)) {}
2958f9d540b0SHoward Hinnant    explicit uniform_int_distribution(const param_type& __p) : __p_(__p) {}
2959f9d540b0SHoward Hinnant    void reset() {}
2960f9d540b0SHoward Hinnant
2961f9d540b0SHoward Hinnant    // generating functions
2962f9d540b0SHoward Hinnant    template<class _URNG> result_type operator()(_URNG& __g)
2963f9d540b0SHoward Hinnant        {return (*this)(__g, __p_);}
2964f9d540b0SHoward Hinnant    template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
2965f9d540b0SHoward Hinnant
2966f9d540b0SHoward Hinnant    // property functions
2967f9d540b0SHoward Hinnant    result_type a() const {return __p_.a();}
2968f9d540b0SHoward Hinnant    result_type b() const {return __p_.b();}
2969f9d540b0SHoward Hinnant
2970f9d540b0SHoward Hinnant    param_type param() const {return __p_;}
2971f9d540b0SHoward Hinnant    void param(const param_type& __p) {__p_ = __p;}
2972f9d540b0SHoward Hinnant
2973f9d540b0SHoward Hinnant    result_type min() const {return a();}
2974f9d540b0SHoward Hinnant    result_type max() const {return b();}
2975f9d540b0SHoward Hinnant
2976f9d540b0SHoward Hinnant    friend bool operator==(const uniform_int_distribution& __x,
2977f9d540b0SHoward Hinnant                           const uniform_int_distribution& __y)
2978f9d540b0SHoward Hinnant        {return __x.__p_ == __y.__p_;}
2979f9d540b0SHoward Hinnant    friend bool operator!=(const uniform_int_distribution& __x,
2980f9d540b0SHoward Hinnant                           const uniform_int_distribution& __y)
2981f9d540b0SHoward Hinnant            {return !(__x == __y);}
29823e519524SHoward Hinnant};
29833e519524SHoward Hinnant
2984f9d540b0SHoward Hinnanttemplate<class _IntType>
2985f9d540b0SHoward Hinnanttemplate<class _URNG>
2986f9d540b0SHoward Hinnanttypename uniform_int_distribution<_IntType>::result_type
2987f9d540b0SHoward Hinnantuniform_int_distribution<_IntType>::operator()(_URNG& __g, const param_type& __p)
29882dd53352SMarshall Clow_LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK
29893e519524SHoward Hinnant{
2990f9d540b0SHoward Hinnant    typedef typename conditional<sizeof(result_type) <= sizeof(uint32_t),
2991f9d540b0SHoward Hinnant                                            uint32_t, uint64_t>::type _UIntType;
29922dd53352SMarshall Clow    const _UIntType _Rp = _UIntType(__p.b()) - _UIntType(__p.a()) + _UIntType(1);
2993c003db1fSHoward Hinnant    if (_Rp == 1)
2994f9d540b0SHoward Hinnant        return __p.a();
2995f9d540b0SHoward Hinnant    const size_t _Dt = numeric_limits<_UIntType>::digits;
2996f9d540b0SHoward Hinnant    typedef __independent_bits_engine<_URNG, _UIntType> _Eng;
2997c003db1fSHoward Hinnant    if (_Rp == 0)
2998f9d540b0SHoward Hinnant        return static_cast<result_type>(_Eng(__g, _Dt)());
2999c003db1fSHoward Hinnant    size_t __w = _Dt - __clz(_Rp) - 1;
3000a6438ca1SMarshall Clow    if ((_Rp & (std::numeric_limits<_UIntType>::max() >> (_Dt - __w))) != 0)
3001f9d540b0SHoward Hinnant        ++__w;
3002f9d540b0SHoward Hinnant    _Eng __e(__g, __w);
3003f9d540b0SHoward Hinnant    _UIntType __u;
3004f9d540b0SHoward Hinnant    do
30053e519524SHoward Hinnant    {
3006f9d540b0SHoward Hinnant        __u = __e();
3007c003db1fSHoward Hinnant    } while (__u >= _Rp);
3008f9d540b0SHoward Hinnant    return static_cast<result_type>(__u + __p.a());
30093e519524SHoward Hinnant}
3010f9d540b0SHoward Hinnant
301166f1ec46SEric Fiselier#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_RANDOM_SHUFFLE) \
301266f1ec46SEric Fiselier  || defined(_LIBCPP_BUILDING_LIBRARY)
3013f0544c20SHoward Hinnantclass _LIBCPP_TYPE_VIS __rs_default;
3014f9d540b0SHoward Hinnant
3015f0544c20SHoward Hinnant_LIBCPP_FUNC_VIS __rs_default __rs_get();
3016f9d540b0SHoward Hinnant
3017f0544c20SHoward Hinnantclass _LIBCPP_TYPE_VIS __rs_default
30183e519524SHoward Hinnant{
3019f9d540b0SHoward Hinnant    static unsigned __c_;
3020f9d540b0SHoward Hinnant
3021f9d540b0SHoward Hinnant    __rs_default();
3022f9d540b0SHoward Hinnantpublic:
3023b6e5f854SMarshall Clow    typedef uint_fast32_t result_type;
3024f9d540b0SHoward Hinnant
3025f9d540b0SHoward Hinnant    static const result_type _Min = 0;
3026f9d540b0SHoward Hinnant    static const result_type _Max = 0xFFFFFFFF;
3027f9d540b0SHoward Hinnant
3028f9d540b0SHoward Hinnant    __rs_default(const __rs_default&);
3029f9d540b0SHoward Hinnant    ~__rs_default();
3030f9d540b0SHoward Hinnant
3031f9d540b0SHoward Hinnant    result_type operator()();
3032f9d540b0SHoward Hinnant
3033788c9979SHoward Hinnant    static _LIBCPP_CONSTEXPR result_type min() {return _Min;}
3034788c9979SHoward Hinnant    static _LIBCPP_CONSTEXPR result_type max() {return _Max;}
3035f9d540b0SHoward Hinnant
3036f0544c20SHoward Hinnant    friend _LIBCPP_FUNC_VIS __rs_default __rs_get();
3037f9d540b0SHoward Hinnant};
3038f9d540b0SHoward Hinnant
3039f0544c20SHoward Hinnant_LIBCPP_FUNC_VIS __rs_default __rs_get();
30403e519524SHoward Hinnant
30413e519524SHoward Hinnanttemplate <class _RandomAccessIterator>
3042ea5cd3b4SLouis Dionne_LIBCPP_DEPRECATED_IN_CXX14 void
30433e519524SHoward Hinnantrandom_shuffle(_RandomAccessIterator __first, _RandomAccessIterator __last)
30443e519524SHoward Hinnant{
30453e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
3046c003db1fSHoward Hinnant    typedef uniform_int_distribution<ptrdiff_t> _Dp;
3047c003db1fSHoward Hinnant    typedef typename _Dp::param_type _Pp;
30483e519524SHoward Hinnant    difference_type __d = __last - __first;
30493e519524SHoward Hinnant    if (__d > 1)
30503e519524SHoward Hinnant    {
3051c003db1fSHoward Hinnant        _Dp __uid;
3052f9d540b0SHoward Hinnant        __rs_default __g = __rs_get();
30535a8525e0SMarshall Clow        for (--__last, (void) --__d; __first < __last; ++__first, (void) --__d)
3054007b26beSHoward Hinnant        {
3055c003db1fSHoward Hinnant            difference_type __i = __uid(__g, _Pp(0, __d));
3056007b26beSHoward Hinnant            if (__i != difference_type(0))
3057007b26beSHoward Hinnant                swap(*__first, *(__first + __i));
3058007b26beSHoward Hinnant        }
30593e519524SHoward Hinnant    }
30603e519524SHoward Hinnant}
30613e519524SHoward Hinnant
30623e519524SHoward Hinnanttemplate <class _RandomAccessIterator, class _RandomNumberGenerator>
3063ea5cd3b4SLouis Dionne_LIBCPP_DEPRECATED_IN_CXX14 void
30643e519524SHoward Hinnantrandom_shuffle(_RandomAccessIterator __first, _RandomAccessIterator __last,
3065ddda456aSEric Fiselier#ifndef _LIBCPP_CXX03_LANG
30663e519524SHoward Hinnant               _RandomNumberGenerator&& __rand)
30673e519524SHoward Hinnant#else
30683e519524SHoward Hinnant               _RandomNumberGenerator& __rand)
30693e519524SHoward Hinnant#endif
30703e519524SHoward Hinnant{
30713e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
30723e519524SHoward Hinnant    difference_type __d = __last - __first;
30733e519524SHoward Hinnant    if (__d > 1)
30743e519524SHoward Hinnant    {
30755a8525e0SMarshall Clow        for (--__last; __first < __last; ++__first, (void) --__d)
3076007b26beSHoward Hinnant        {
3077007b26beSHoward Hinnant            difference_type __i = __rand(__d);
3078e9cc5451SMarshall Clow            if (__i != difference_type(0))
3079007b26beSHoward Hinnant              swap(*__first, *(__first + __i));
3080007b26beSHoward Hinnant        }
30813e519524SHoward Hinnant    }
30823e519524SHoward Hinnant}
30830f37a410SMarshall Clow#endif
30843e519524SHoward Hinnant
3085e7154709SEric Fiseliertemplate <class _PopulationIterator, class _SampleIterator, class _Distance,
3086e7154709SEric Fiselier          class _UniformRandomNumberGenerator>
3087e7154709SEric Fiselier_LIBCPP_INLINE_VISIBILITY
3088e7154709SEric Fiselier_SampleIterator __sample(_PopulationIterator __first,
308942bfedd9SAlexander Richardson                         _PopulationIterator __last, _SampleIterator __output_iter,
3090e7154709SEric Fiselier                         _Distance __n,
3091e7154709SEric Fiselier                         _UniformRandomNumberGenerator & __g,
3092e7154709SEric Fiselier                         input_iterator_tag) {
3093e7154709SEric Fiselier
3094e7154709SEric Fiselier  _Distance __k = 0;
3095e7154709SEric Fiselier  for (; __first != __last && __k < __n; ++__first, (void)++__k)
309642bfedd9SAlexander Richardson    __output_iter[__k] = *__first;
3097e7154709SEric Fiselier  _Distance __sz = __k;
3098e7154709SEric Fiselier  for (; __first != __last; ++__first, (void)++__k) {
3099e7154709SEric Fiselier    _Distance __r = _VSTD::uniform_int_distribution<_Distance>(0, __k)(__g);
3100e7154709SEric Fiselier    if (__r < __sz)
310142bfedd9SAlexander Richardson      __output_iter[__r] = *__first;
3102e7154709SEric Fiselier  }
310342bfedd9SAlexander Richardson  return __output_iter + _VSTD::min(__n, __k);
3104e7154709SEric Fiselier}
3105e7154709SEric Fiselier
3106e7154709SEric Fiseliertemplate <class _PopulationIterator, class _SampleIterator, class _Distance,
3107e7154709SEric Fiselier          class _UniformRandomNumberGenerator>
3108e7154709SEric Fiselier_LIBCPP_INLINE_VISIBILITY
3109e7154709SEric Fiselier_SampleIterator __sample(_PopulationIterator __first,
311042bfedd9SAlexander Richardson                         _PopulationIterator __last, _SampleIterator __output_iter,
3111e7154709SEric Fiselier                         _Distance __n,
3112e7154709SEric Fiselier                         _UniformRandomNumberGenerator& __g,
3113e7154709SEric Fiselier                         forward_iterator_tag) {
3114e7154709SEric Fiselier  _Distance __unsampled_sz = _VSTD::distance(__first, __last);
3115e7154709SEric Fiselier  for (__n = _VSTD::min(__n, __unsampled_sz); __n != 0; ++__first) {
3116e7154709SEric Fiselier    _Distance __r =
3117e7154709SEric Fiselier        _VSTD::uniform_int_distribution<_Distance>(0, --__unsampled_sz)(__g);
3118e7154709SEric Fiselier    if (__r < __n) {
311942bfedd9SAlexander Richardson      *__output_iter++ = *__first;
3120e7154709SEric Fiselier      --__n;
3121e7154709SEric Fiselier    }
3122e7154709SEric Fiselier  }
312342bfedd9SAlexander Richardson  return __output_iter;
3124e7154709SEric Fiselier}
3125e7154709SEric Fiselier
3126e7154709SEric Fiseliertemplate <class _PopulationIterator, class _SampleIterator, class _Distance,
3127e7154709SEric Fiselier          class _UniformRandomNumberGenerator>
3128e7154709SEric Fiselier_LIBCPP_INLINE_VISIBILITY
3129e7154709SEric Fiselier_SampleIterator __sample(_PopulationIterator __first,
313042bfedd9SAlexander Richardson                         _PopulationIterator __last, _SampleIterator __output_iter,
3131e7154709SEric Fiselier                         _Distance __n, _UniformRandomNumberGenerator& __g) {
3132e7154709SEric Fiselier  typedef typename iterator_traits<_PopulationIterator>::iterator_category
3133e7154709SEric Fiselier        _PopCategory;
3134e7154709SEric Fiselier  typedef typename iterator_traits<_PopulationIterator>::difference_type
3135e7154709SEric Fiselier        _Difference;
3136e7154709SEric Fiselier  static_assert(__is_forward_iterator<_PopulationIterator>::value ||
3137e7154709SEric Fiselier                __is_random_access_iterator<_SampleIterator>::value,
3138e7154709SEric Fiselier                "SampleIterator must meet the requirements of RandomAccessIterator");
3139e7154709SEric Fiselier  typedef typename common_type<_Distance, _Difference>::type _CommonType;
3140e7154709SEric Fiselier  _LIBCPP_ASSERT(__n >= 0, "N must be a positive number.");
3141e7154709SEric Fiselier  return _VSTD::__sample(
314242bfedd9SAlexander Richardson      __first, __last, __output_iter, _CommonType(__n),
3143e7154709SEric Fiselier      __g, _PopCategory());
3144e7154709SEric Fiselier}
3145e7154709SEric Fiselier
3146e7154709SEric Fiselier#if _LIBCPP_STD_VER > 14
3147e7154709SEric Fiseliertemplate <class _PopulationIterator, class _SampleIterator, class _Distance,
3148e7154709SEric Fiselier          class _UniformRandomNumberGenerator>
3149e7154709SEric Fiselierinline _LIBCPP_INLINE_VISIBILITY
3150e7154709SEric Fiselier_SampleIterator sample(_PopulationIterator __first,
315142bfedd9SAlexander Richardson                       _PopulationIterator __last, _SampleIterator __output_iter,
3152e7154709SEric Fiselier                       _Distance __n, _UniformRandomNumberGenerator&& __g) {
315342bfedd9SAlexander Richardson    return _VSTD::__sample(__first, __last, __output_iter, __n, __g);
3154e7154709SEric Fiselier}
3155e7154709SEric Fiselier#endif // _LIBCPP_STD_VER > 14
3156e7154709SEric Fiselier
3157f9d540b0SHoward Hinnanttemplate<class _RandomAccessIterator, class _UniformRandomNumberGenerator>
3158f9d540b0SHoward Hinnant    void shuffle(_RandomAccessIterator __first, _RandomAccessIterator __last,
3159ddda456aSEric Fiselier#ifndef _LIBCPP_CXX03_LANG
3160fb340102SHoward Hinnant                 _UniformRandomNumberGenerator&& __g)
3161fb340102SHoward Hinnant#else
3162f9d540b0SHoward Hinnant                 _UniformRandomNumberGenerator& __g)
3163fb340102SHoward Hinnant#endif
3164f9d540b0SHoward Hinnant{
3165f9d540b0SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
3166c003db1fSHoward Hinnant    typedef uniform_int_distribution<ptrdiff_t> _Dp;
3167c003db1fSHoward Hinnant    typedef typename _Dp::param_type _Pp;
3168f9d540b0SHoward Hinnant    difference_type __d = __last - __first;
3169f9d540b0SHoward Hinnant    if (__d > 1)
3170f9d540b0SHoward Hinnant    {
3171c003db1fSHoward Hinnant        _Dp __uid;
3172f9d540b0SHoward Hinnant        for (--__last, --__d; __first < __last; ++__first, --__d)
3173007b26beSHoward Hinnant        {
3174c003db1fSHoward Hinnant            difference_type __i = __uid(__g, _Pp(0, __d));
3175007b26beSHoward Hinnant            if (__i != difference_type(0))
3176007b26beSHoward Hinnant                swap(*__first, *(__first + __i));
3177007b26beSHoward Hinnant        }
3178f9d540b0SHoward Hinnant    }
3179f9d540b0SHoward Hinnant}
3180f9d540b0SHoward Hinnant
31813e519524SHoward Hinnanttemplate <class _InputIterator, class _Predicate>
3182*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
31833e519524SHoward Hinnantis_partitioned(_InputIterator __first, _InputIterator __last, _Predicate __pred)
31843e519524SHoward Hinnant{
31853e519524SHoward Hinnant    for (; __first != __last; ++__first)
31863e519524SHoward Hinnant        if (!__pred(*__first))
31873e519524SHoward Hinnant            break;
3188b9595b79SMarshall Clow    if ( __first == __last )
3189b9595b79SMarshall Clow        return true;
3190b9595b79SMarshall Clow    ++__first;
31913e519524SHoward Hinnant    for (; __first != __last; ++__first)
31923e519524SHoward Hinnant        if (__pred(*__first))
31933e519524SHoward Hinnant            return false;
31943e519524SHoward Hinnant    return true;
31953e519524SHoward Hinnant}
31963e519524SHoward Hinnant
31973e519524SHoward Hinnant// partition
31983e519524SHoward Hinnant
31993e519524SHoward Hinnanttemplate <class _Predicate, class _ForwardIterator>
32003e519524SHoward Hinnant_ForwardIterator
32013e519524SHoward Hinnant__partition(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred, forward_iterator_tag)
32023e519524SHoward Hinnant{
32033e519524SHoward Hinnant    while (true)
32043e519524SHoward Hinnant    {
32053e519524SHoward Hinnant        if (__first == __last)
32063e519524SHoward Hinnant            return __first;
32073e519524SHoward Hinnant        if (!__pred(*__first))
32083e519524SHoward Hinnant            break;
32093e519524SHoward Hinnant        ++__first;
32103e519524SHoward Hinnant    }
32113e519524SHoward Hinnant    for (_ForwardIterator __p = __first; ++__p != __last;)
32123e519524SHoward Hinnant    {
32133e519524SHoward Hinnant        if (__pred(*__p))
32143e519524SHoward Hinnant        {
32153e519524SHoward Hinnant            swap(*__first, *__p);
32163e519524SHoward Hinnant            ++__first;
32173e519524SHoward Hinnant        }
32183e519524SHoward Hinnant    }
32193e519524SHoward Hinnant    return __first;
32203e519524SHoward Hinnant}
32213e519524SHoward Hinnant
32223e519524SHoward Hinnanttemplate <class _Predicate, class _BidirectionalIterator>
32233e519524SHoward Hinnant_BidirectionalIterator
32243e519524SHoward Hinnant__partition(_BidirectionalIterator __first, _BidirectionalIterator __last, _Predicate __pred,
32253e519524SHoward Hinnant            bidirectional_iterator_tag)
32263e519524SHoward Hinnant{
32273e519524SHoward Hinnant    while (true)
32283e519524SHoward Hinnant    {
32293e519524SHoward Hinnant        while (true)
32303e519524SHoward Hinnant        {
32313e519524SHoward Hinnant            if (__first == __last)
32323e519524SHoward Hinnant                return __first;
32333e519524SHoward Hinnant            if (!__pred(*__first))
32343e519524SHoward Hinnant                break;
32353e519524SHoward Hinnant            ++__first;
32363e519524SHoward Hinnant        }
32373e519524SHoward Hinnant        do
32383e519524SHoward Hinnant        {
32393e519524SHoward Hinnant            if (__first == --__last)
32403e519524SHoward Hinnant                return __first;
32413e519524SHoward Hinnant        } while (!__pred(*__last));
32423e519524SHoward Hinnant        swap(*__first, *__last);
32433e519524SHoward Hinnant        ++__first;
32443e519524SHoward Hinnant    }
32453e519524SHoward Hinnant}
32463e519524SHoward Hinnant
32473e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Predicate>
32483e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
32493e519524SHoward Hinnant_ForwardIterator
32503e519524SHoward Hinnantpartition(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred)
32513e519524SHoward Hinnant{
3252ce48a113SHoward Hinnant    return _VSTD::__partition<typename add_lvalue_reference<_Predicate>::type>
32533e519524SHoward Hinnant                            (__first, __last, __pred, typename iterator_traits<_ForwardIterator>::iterator_category());
32543e519524SHoward Hinnant}
32553e519524SHoward Hinnant
32563e519524SHoward Hinnant// partition_copy
32573e519524SHoward Hinnant
32583e519524SHoward Hinnanttemplate <class _InputIterator, class _OutputIterator1,
32593e519524SHoward Hinnant          class _OutputIterator2, class _Predicate>
32601b9a4ffdSMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 pair<_OutputIterator1, _OutputIterator2>
32613e519524SHoward Hinnantpartition_copy(_InputIterator __first, _InputIterator __last,
32623e519524SHoward Hinnant               _OutputIterator1 __out_true, _OutputIterator2 __out_false,
32633e519524SHoward Hinnant               _Predicate __pred)
32643e519524SHoward Hinnant{
32653e519524SHoward Hinnant    for (; __first != __last; ++__first)
32663e519524SHoward Hinnant    {
32673e519524SHoward Hinnant        if (__pred(*__first))
32683e519524SHoward Hinnant        {
32693e519524SHoward Hinnant            *__out_true = *__first;
32703e519524SHoward Hinnant            ++__out_true;
32713e519524SHoward Hinnant        }
32723e519524SHoward Hinnant        else
32733e519524SHoward Hinnant        {
32743e519524SHoward Hinnant            *__out_false = *__first;
32753e519524SHoward Hinnant            ++__out_false;
32763e519524SHoward Hinnant        }
32773e519524SHoward Hinnant    }
32783e519524SHoward Hinnant    return pair<_OutputIterator1, _OutputIterator2>(__out_true, __out_false);
32793e519524SHoward Hinnant}
32803e519524SHoward Hinnant
32813e519524SHoward Hinnant// partition_point
32823e519524SHoward Hinnant
32833e519524SHoward Hinnanttemplate<class _ForwardIterator, class _Predicate>
3284674f9128SMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
32853e519524SHoward Hinnantpartition_point(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred)
32863e519524SHoward Hinnant{
32873e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator>::difference_type difference_type;
3288ce48a113SHoward Hinnant    difference_type __len = _VSTD::distance(__first, __last);
32893e519524SHoward Hinnant    while (__len != 0)
32903e519524SHoward Hinnant    {
329104695a75SLouis Dionne        difference_type __l2 = _VSTD::__half_positive(__len);
32923e519524SHoward Hinnant        _ForwardIterator __m = __first;
3293ce48a113SHoward Hinnant        _VSTD::advance(__m, __l2);
32943e519524SHoward Hinnant        if (__pred(*__m))
32953e519524SHoward Hinnant        {
32963e519524SHoward Hinnant            __first = ++__m;
32973e519524SHoward Hinnant            __len -= __l2 + 1;
32983e519524SHoward Hinnant        }
32993e519524SHoward Hinnant        else
33003e519524SHoward Hinnant            __len = __l2;
33013e519524SHoward Hinnant    }
33023e519524SHoward Hinnant    return __first;
33033e519524SHoward Hinnant}
33043e519524SHoward Hinnant
33053e519524SHoward Hinnant// stable_partition
33063e519524SHoward Hinnant
33073e519524SHoward Hinnanttemplate <class _Predicate, class _ForwardIterator, class _Distance, class _Pair>
33083e519524SHoward Hinnant_ForwardIterator
33093e519524SHoward Hinnant__stable_partition(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred,
33103e519524SHoward Hinnant                   _Distance __len, _Pair __p, forward_iterator_tag __fit)
33113e519524SHoward Hinnant{
33123e519524SHoward Hinnant    // *__first is known to be false
33133e519524SHoward Hinnant    // __len >= 1
33143e519524SHoward Hinnant    if (__len == 1)
33153e519524SHoward Hinnant        return __first;
33163e519524SHoward Hinnant    if (__len == 2)
33173e519524SHoward Hinnant    {
33183e519524SHoward Hinnant        _ForwardIterator __m = __first;
33193e519524SHoward Hinnant        if (__pred(*++__m))
33203e519524SHoward Hinnant        {
33213e519524SHoward Hinnant            swap(*__first, *__m);
33223e519524SHoward Hinnant            return __m;
33233e519524SHoward Hinnant        }
33243e519524SHoward Hinnant        return __first;
33253e519524SHoward Hinnant    }
33263e519524SHoward Hinnant    if (__len <= __p.second)
33273e519524SHoward Hinnant    {   // The buffer is big enough to use
33283e519524SHoward Hinnant        typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
33293e519524SHoward Hinnant        __destruct_n __d(0);
33303e519524SHoward Hinnant        unique_ptr<value_type, __destruct_n&> __h(__p.first, __d);
33313e519524SHoward Hinnant        // Move the falses into the temporary buffer, and the trues to the front of the line
33323e519524SHoward Hinnant        // Update __first to always point to the end of the trues
33333e519524SHoward Hinnant        value_type* __t = __p.first;
3334ce48a113SHoward Hinnant        ::new(__t) value_type(_VSTD::move(*__first));
33353e519524SHoward Hinnant        __d.__incr((value_type*)0);
33363e519524SHoward Hinnant        ++__t;
33373e519524SHoward Hinnant        _ForwardIterator __i = __first;
33383e519524SHoward Hinnant        while (++__i != __last)
33393e519524SHoward Hinnant        {
33403e519524SHoward Hinnant            if (__pred(*__i))
33413e519524SHoward Hinnant            {
3342ce48a113SHoward Hinnant                *__first = _VSTD::move(*__i);
33433e519524SHoward Hinnant                ++__first;
33443e519524SHoward Hinnant            }
33453e519524SHoward Hinnant            else
33463e519524SHoward Hinnant            {
3347ce48a113SHoward Hinnant                ::new(__t) value_type(_VSTD::move(*__i));
33483e519524SHoward Hinnant                __d.__incr((value_type*)0);
33493e519524SHoward Hinnant                ++__t;
33503e519524SHoward Hinnant            }
33513e519524SHoward Hinnant        }
33523e519524SHoward Hinnant        // All trues now at start of range, all falses in buffer
33533e519524SHoward Hinnant        // Move falses back into range, but don't mess up __first which points to first false
33543e519524SHoward Hinnant        __i = __first;
33553e519524SHoward Hinnant        for (value_type* __t2 = __p.first; __t2 < __t; ++__t2, ++__i)
3356ce48a113SHoward Hinnant            *__i = _VSTD::move(*__t2);
33573e519524SHoward Hinnant        // __h destructs moved-from values out of the temp buffer, but doesn't deallocate buffer
33583e519524SHoward Hinnant        return __first;
33593e519524SHoward Hinnant    }
33603e519524SHoward Hinnant    // Else not enough buffer, do in place
33613e519524SHoward Hinnant    // __len >= 3
33623e519524SHoward Hinnant    _ForwardIterator __m = __first;
33633e519524SHoward Hinnant    _Distance __len2 = __len / 2;  // __len2 >= 2
3364ce48a113SHoward Hinnant    _VSTD::advance(__m, __len2);
33653e519524SHoward Hinnant    // recurse on [__first, __m), *__first know to be false
33663e519524SHoward Hinnant    // F?????????????????
33673e519524SHoward Hinnant    // f       m         l
33683e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Predicate>::type _PredRef;
33693e519524SHoward Hinnant    _ForwardIterator __first_false = __stable_partition<_PredRef>(__first, __m, __pred, __len2, __p, __fit);
33703e519524SHoward Hinnant    // TTTFFFFF??????????
33713e519524SHoward Hinnant    // f  ff   m         l
33723e519524SHoward Hinnant    // recurse on [__m, __last], except increase __m until *(__m) is false, *__last know to be true
33733e519524SHoward Hinnant    _ForwardIterator __m1 = __m;
33743e519524SHoward Hinnant    _ForwardIterator __second_false = __last;
33753e519524SHoward Hinnant    _Distance __len_half = __len - __len2;
33763e519524SHoward Hinnant    while (__pred(*__m1))
33773e519524SHoward Hinnant    {
33783e519524SHoward Hinnant        if (++__m1 == __last)
33793e519524SHoward Hinnant            goto __second_half_done;
33803e519524SHoward Hinnant        --__len_half;
33813e519524SHoward Hinnant    }
33823e519524SHoward Hinnant    // TTTFFFFFTTTF??????
33833e519524SHoward Hinnant    // f  ff   m  m1     l
33843e519524SHoward Hinnant    __second_false = __stable_partition<_PredRef>(__m1, __last, __pred, __len_half, __p, __fit);
33853e519524SHoward Hinnant__second_half_done:
33863e519524SHoward Hinnant    // TTTFFFFFTTTTTFFFFF
33873e519524SHoward Hinnant    // f  ff   m    sf   l
3388ce48a113SHoward Hinnant    return _VSTD::rotate(__first_false, __m, __second_false);
33893e519524SHoward Hinnant    // TTTTTTTTFFFFFFFFFF
33903e519524SHoward Hinnant    //         |
33913e519524SHoward Hinnant}
33923e519524SHoward Hinnant
33933e519524SHoward Hinnantstruct __return_temporary_buffer
33943e519524SHoward Hinnant{
33953e519524SHoward Hinnant    template <class _Tp>
3396ce48a113SHoward Hinnant    _LIBCPP_INLINE_VISIBILITY void operator()(_Tp* __p) const {_VSTD::return_temporary_buffer(__p);}
33973e519524SHoward Hinnant};
33983e519524SHoward Hinnant
33993e519524SHoward Hinnanttemplate <class _Predicate, class _ForwardIterator>
34003e519524SHoward Hinnant_ForwardIterator
34013e519524SHoward Hinnant__stable_partition(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred,
34023e519524SHoward Hinnant                   forward_iterator_tag)
34033e519524SHoward Hinnant{
34043e519524SHoward Hinnant    const unsigned __alloc_limit = 3;  // might want to make this a function of trivial assignment
34053e519524SHoward Hinnant    // Either prove all true and return __first or point to first false
34063e519524SHoward Hinnant    while (true)
34073e519524SHoward Hinnant    {
34083e519524SHoward Hinnant        if (__first == __last)
34093e519524SHoward Hinnant            return __first;
34103e519524SHoward Hinnant        if (!__pred(*__first))
34113e519524SHoward Hinnant            break;
34123e519524SHoward Hinnant        ++__first;
34133e519524SHoward Hinnant    }
34143e519524SHoward Hinnant    // We now have a reduced range [__first, __last)
34153e519524SHoward Hinnant    // *__first is known to be false
34163e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator>::difference_type difference_type;
34173e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
3418ce48a113SHoward Hinnant    difference_type __len = _VSTD::distance(__first, __last);
34193e519524SHoward Hinnant    pair<value_type*, ptrdiff_t> __p(0, 0);
34203e519524SHoward Hinnant    unique_ptr<value_type, __return_temporary_buffer> __h;
34213e519524SHoward Hinnant    if (__len >= __alloc_limit)
34223e519524SHoward Hinnant    {
3423ce48a113SHoward Hinnant        __p = _VSTD::get_temporary_buffer<value_type>(__len);
34243e519524SHoward Hinnant        __h.reset(__p.first);
34253e519524SHoward Hinnant    }
34263e519524SHoward Hinnant    return __stable_partition<typename add_lvalue_reference<_Predicate>::type>
34273e519524SHoward Hinnant                             (__first, __last, __pred, __len, __p, forward_iterator_tag());
34283e519524SHoward Hinnant}
34293e519524SHoward Hinnant
34303e519524SHoward Hinnanttemplate <class _Predicate, class _BidirectionalIterator, class _Distance, class _Pair>
34313e519524SHoward Hinnant_BidirectionalIterator
34323e519524SHoward Hinnant__stable_partition(_BidirectionalIterator __first, _BidirectionalIterator __last, _Predicate __pred,
34333e519524SHoward Hinnant                   _Distance __len, _Pair __p, bidirectional_iterator_tag __bit)
34343e519524SHoward Hinnant{
34353e519524SHoward Hinnant    // *__first is known to be false
34363e519524SHoward Hinnant    // *__last is known to be true
34373e519524SHoward Hinnant    // __len >= 2
34383e519524SHoward Hinnant    if (__len == 2)
34393e519524SHoward Hinnant    {
34403e519524SHoward Hinnant        swap(*__first, *__last);
34413e519524SHoward Hinnant        return __last;
34423e519524SHoward Hinnant    }
34433e519524SHoward Hinnant    if (__len == 3)
34443e519524SHoward Hinnant    {
34453e519524SHoward Hinnant        _BidirectionalIterator __m = __first;
34463e519524SHoward Hinnant        if (__pred(*++__m))
34473e519524SHoward Hinnant        {
34483e519524SHoward Hinnant            swap(*__first, *__m);
34493e519524SHoward Hinnant            swap(*__m, *__last);
34503e519524SHoward Hinnant            return __last;
34513e519524SHoward Hinnant        }
34523e519524SHoward Hinnant        swap(*__m, *__last);
34533e519524SHoward Hinnant        swap(*__first, *__m);
34543e519524SHoward Hinnant        return __m;
34553e519524SHoward Hinnant    }
34563e519524SHoward Hinnant    if (__len <= __p.second)
34573e519524SHoward Hinnant    {   // The buffer is big enough to use
34583e519524SHoward Hinnant        typedef typename iterator_traits<_BidirectionalIterator>::value_type value_type;
34593e519524SHoward Hinnant        __destruct_n __d(0);
34603e519524SHoward Hinnant        unique_ptr<value_type, __destruct_n&> __h(__p.first, __d);
34613e519524SHoward Hinnant        // Move the falses into the temporary buffer, and the trues to the front of the line
34623e519524SHoward Hinnant        // Update __first to always point to the end of the trues
34633e519524SHoward Hinnant        value_type* __t = __p.first;
3464ce48a113SHoward Hinnant        ::new(__t) value_type(_VSTD::move(*__first));
34653e519524SHoward Hinnant        __d.__incr((value_type*)0);
34663e519524SHoward Hinnant        ++__t;
34673e519524SHoward Hinnant        _BidirectionalIterator __i = __first;
34683e519524SHoward Hinnant        while (++__i != __last)
34693e519524SHoward Hinnant        {
34703e519524SHoward Hinnant            if (__pred(*__i))
34713e519524SHoward Hinnant            {
3472ce48a113SHoward Hinnant                *__first = _VSTD::move(*__i);
34733e519524SHoward Hinnant                ++__first;
34743e519524SHoward Hinnant            }
34753e519524SHoward Hinnant            else
34763e519524SHoward Hinnant            {
3477ce48a113SHoward Hinnant                ::new(__t) value_type(_VSTD::move(*__i));
34783e519524SHoward Hinnant                __d.__incr((value_type*)0);
34793e519524SHoward Hinnant                ++__t;
34803e519524SHoward Hinnant            }
34813e519524SHoward Hinnant        }
34823e519524SHoward Hinnant        // move *__last, known to be true
3483ce48a113SHoward Hinnant        *__first = _VSTD::move(*__i);
34843e519524SHoward Hinnant        __i = ++__first;
34853e519524SHoward Hinnant        // All trues now at start of range, all falses in buffer
34863e519524SHoward Hinnant        // Move falses back into range, but don't mess up __first which points to first false
34873e519524SHoward Hinnant        for (value_type* __t2 = __p.first; __t2 < __t; ++__t2, ++__i)
3488ce48a113SHoward Hinnant            *__i = _VSTD::move(*__t2);
34893e519524SHoward Hinnant        // __h destructs moved-from values out of the temp buffer, but doesn't deallocate buffer
34903e519524SHoward Hinnant        return __first;
34913e519524SHoward Hinnant    }
34923e519524SHoward Hinnant    // Else not enough buffer, do in place
34933e519524SHoward Hinnant    // __len >= 4
34943e519524SHoward Hinnant    _BidirectionalIterator __m = __first;
34953e519524SHoward Hinnant    _Distance __len2 = __len / 2;  // __len2 >= 2
3496ce48a113SHoward Hinnant    _VSTD::advance(__m, __len2);
34973e519524SHoward Hinnant    // recurse on [__first, __m-1], except reduce __m-1 until *(__m-1) is true, *__first know to be false
34983e519524SHoward Hinnant    // F????????????????T
34993e519524SHoward Hinnant    // f       m        l
35003e519524SHoward Hinnant    _BidirectionalIterator __m1 = __m;
35013e519524SHoward Hinnant    _BidirectionalIterator __first_false = __first;
35023e519524SHoward Hinnant    _Distance __len_half = __len2;
35033e519524SHoward Hinnant    while (!__pred(*--__m1))
35043e519524SHoward Hinnant    {
35053e519524SHoward Hinnant        if (__m1 == __first)
35063e519524SHoward Hinnant            goto __first_half_done;
35073e519524SHoward Hinnant        --__len_half;
35083e519524SHoward Hinnant    }
35093e519524SHoward Hinnant    // F???TFFF?????????T
35103e519524SHoward Hinnant    // f   m1  m        l
35113e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Predicate>::type _PredRef;
35123e519524SHoward Hinnant    __first_false = __stable_partition<_PredRef>(__first, __m1, __pred, __len_half, __p, __bit);
35133e519524SHoward Hinnant__first_half_done:
35143e519524SHoward Hinnant    // TTTFFFFF?????????T
35153e519524SHoward Hinnant    // f  ff   m        l
35163e519524SHoward Hinnant    // recurse on [__m, __last], except increase __m until *(__m) is false, *__last know to be true
35173e519524SHoward Hinnant    __m1 = __m;
35183e519524SHoward Hinnant    _BidirectionalIterator __second_false = __last;
35193e519524SHoward Hinnant    ++__second_false;
35203e519524SHoward Hinnant    __len_half = __len - __len2;
35213e519524SHoward Hinnant    while (__pred(*__m1))
35223e519524SHoward Hinnant    {
35233e519524SHoward Hinnant        if (++__m1 == __last)
35243e519524SHoward Hinnant            goto __second_half_done;
35253e519524SHoward Hinnant        --__len_half;
35263e519524SHoward Hinnant    }
35273e519524SHoward Hinnant    // TTTFFFFFTTTF?????T
35283e519524SHoward Hinnant    // f  ff   m  m1    l
35293e519524SHoward Hinnant    __second_false = __stable_partition<_PredRef>(__m1, __last, __pred, __len_half, __p, __bit);
35303e519524SHoward Hinnant__second_half_done:
35313e519524SHoward Hinnant    // TTTFFFFFTTTTTFFFFF
35323e519524SHoward Hinnant    // f  ff   m    sf  l
3533ce48a113SHoward Hinnant    return _VSTD::rotate(__first_false, __m, __second_false);
35343e519524SHoward Hinnant    // TTTTTTTTFFFFFFFFFF
35353e519524SHoward Hinnant    //         |
35363e519524SHoward Hinnant}
35373e519524SHoward Hinnant
35383e519524SHoward Hinnanttemplate <class _Predicate, class _BidirectionalIterator>
35393e519524SHoward Hinnant_BidirectionalIterator
35403e519524SHoward Hinnant__stable_partition(_BidirectionalIterator __first, _BidirectionalIterator __last, _Predicate __pred,
35413e519524SHoward Hinnant                   bidirectional_iterator_tag)
35423e519524SHoward Hinnant{
35433e519524SHoward Hinnant    typedef typename iterator_traits<_BidirectionalIterator>::difference_type difference_type;
35443e519524SHoward Hinnant    typedef typename iterator_traits<_BidirectionalIterator>::value_type value_type;
35453e519524SHoward Hinnant    const difference_type __alloc_limit = 4;  // might want to make this a function of trivial assignment
35463e519524SHoward Hinnant    // Either prove all true and return __first or point to first false
35473e519524SHoward Hinnant    while (true)
35483e519524SHoward Hinnant    {
35493e519524SHoward Hinnant        if (__first == __last)
35503e519524SHoward Hinnant            return __first;
35513e519524SHoward Hinnant        if (!__pred(*__first))
35523e519524SHoward Hinnant            break;
35533e519524SHoward Hinnant        ++__first;
35543e519524SHoward Hinnant    }
35553e519524SHoward Hinnant    // __first points to first false, everything prior to __first is already set.
35563e519524SHoward Hinnant    // Either prove [__first, __last) is all false and return __first, or point __last to last true
35573e519524SHoward Hinnant    do
35583e519524SHoward Hinnant    {
35593e519524SHoward Hinnant        if (__first == --__last)
35603e519524SHoward Hinnant            return __first;
35613e519524SHoward Hinnant    } while (!__pred(*__last));
35623e519524SHoward Hinnant    // We now have a reduced range [__first, __last]
35633e519524SHoward Hinnant    // *__first is known to be false
35643e519524SHoward Hinnant    // *__last is known to be true
35653e519524SHoward Hinnant    // __len >= 2
3566ce48a113SHoward Hinnant    difference_type __len = _VSTD::distance(__first, __last) + 1;
35673e519524SHoward Hinnant    pair<value_type*, ptrdiff_t> __p(0, 0);
35683e519524SHoward Hinnant    unique_ptr<value_type, __return_temporary_buffer> __h;
35693e519524SHoward Hinnant    if (__len >= __alloc_limit)
35703e519524SHoward Hinnant    {
3571ce48a113SHoward Hinnant        __p = _VSTD::get_temporary_buffer<value_type>(__len);
35723e519524SHoward Hinnant        __h.reset(__p.first);
35733e519524SHoward Hinnant    }
35743e519524SHoward Hinnant    return __stable_partition<typename add_lvalue_reference<_Predicate>::type>
35753e519524SHoward Hinnant                             (__first, __last, __pred, __len, __p, bidirectional_iterator_tag());
35763e519524SHoward Hinnant}
35773e519524SHoward Hinnant
35783e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Predicate>
35793e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
35803e519524SHoward Hinnant_ForwardIterator
35813e519524SHoward Hinnantstable_partition(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred)
35823e519524SHoward Hinnant{
35833e519524SHoward Hinnant    return __stable_partition<typename add_lvalue_reference<_Predicate>::type>
35843e519524SHoward Hinnant                             (__first, __last, __pred, typename iterator_traits<_ForwardIterator>::iterator_category());
35853e519524SHoward Hinnant}
35863e519524SHoward Hinnant
35873e519524SHoward Hinnant// is_sorted_until
35883e519524SHoward Hinnant
35893e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Compare>
3590*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
35913e519524SHoward Hinnantis_sorted_until(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp)
35923e519524SHoward Hinnant{
35933e519524SHoward Hinnant    if (__first != __last)
35943e519524SHoward Hinnant    {
35953e519524SHoward Hinnant        _ForwardIterator __i = __first;
35963e519524SHoward Hinnant        while (++__i != __last)
35973e519524SHoward Hinnant        {
35983e519524SHoward Hinnant            if (__comp(*__i, *__first))
35993e519524SHoward Hinnant                return __i;
36003e519524SHoward Hinnant            __first = __i;
36013e519524SHoward Hinnant        }
36023e519524SHoward Hinnant    }
36033e519524SHoward Hinnant    return __last;
36043e519524SHoward Hinnant}
36053e519524SHoward Hinnant
36063e519524SHoward Hinnanttemplate<class _ForwardIterator>
3607*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
3608*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
36093e519524SHoward Hinnant_ForwardIterator
36103e519524SHoward Hinnantis_sorted_until(_ForwardIterator __first, _ForwardIterator __last)
36113e519524SHoward Hinnant{
3612ce48a113SHoward Hinnant    return _VSTD::is_sorted_until(__first, __last, __less<typename iterator_traits<_ForwardIterator>::value_type>());
36133e519524SHoward Hinnant}
36143e519524SHoward Hinnant
36153e519524SHoward Hinnant// is_sorted
36163e519524SHoward Hinnant
36173e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Compare>
3618*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
3619*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
36203e519524SHoward Hinnantbool
36213e519524SHoward Hinnantis_sorted(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp)
36223e519524SHoward Hinnant{
3623ce48a113SHoward Hinnant    return _VSTD::is_sorted_until(__first, __last, __comp) == __last;
36243e519524SHoward Hinnant}
36253e519524SHoward Hinnant
36263e519524SHoward Hinnanttemplate<class _ForwardIterator>
3627*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
3628*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
36293e519524SHoward Hinnantbool
36303e519524SHoward Hinnantis_sorted(_ForwardIterator __first, _ForwardIterator __last)
36313e519524SHoward Hinnant{
3632ce48a113SHoward Hinnant    return _VSTD::is_sorted(__first, __last, __less<typename iterator_traits<_ForwardIterator>::value_type>());
36333e519524SHoward Hinnant}
36343e519524SHoward Hinnant
36353e519524SHoward Hinnant// sort
36363e519524SHoward Hinnant
36373e519524SHoward Hinnant// stable, 2-3 compares, 0-2 swaps
36383e519524SHoward Hinnant
36393e519524SHoward Hinnanttemplate <class _Compare, class _ForwardIterator>
36403e519524SHoward Hinnantunsigned
36413e519524SHoward Hinnant__sort3(_ForwardIterator __x, _ForwardIterator __y, _ForwardIterator __z, _Compare __c)
36423e519524SHoward Hinnant{
36433e519524SHoward Hinnant    unsigned __r = 0;
36443e519524SHoward Hinnant    if (!__c(*__y, *__x))          // if x <= y
36453e519524SHoward Hinnant    {
36463e519524SHoward Hinnant        if (!__c(*__z, *__y))      // if y <= z
36473e519524SHoward Hinnant            return __r;            // x <= y && y <= z
36483e519524SHoward Hinnant                                   // x <= y && y > z
36493e519524SHoward Hinnant        swap(*__y, *__z);          // x <= z && y < z
36503e519524SHoward Hinnant        __r = 1;
36513e519524SHoward Hinnant        if (__c(*__y, *__x))       // if x > y
36523e519524SHoward Hinnant        {
36533e519524SHoward Hinnant            swap(*__x, *__y);      // x < y && y <= z
36543e519524SHoward Hinnant            __r = 2;
36553e519524SHoward Hinnant        }
36563e519524SHoward Hinnant        return __r;                // x <= y && y < z
36573e519524SHoward Hinnant    }
36583e519524SHoward Hinnant    if (__c(*__z, *__y))           // x > y, if y > z
36593e519524SHoward Hinnant    {
36603e519524SHoward Hinnant        swap(*__x, *__z);          // x < y && y < z
36613e519524SHoward Hinnant        __r = 1;
36623e519524SHoward Hinnant        return __r;
36633e519524SHoward Hinnant    }
36643e519524SHoward Hinnant    swap(*__x, *__y);              // x > y && y <= z
36653e519524SHoward Hinnant    __r = 1;                       // x < y && x <= z
36663e519524SHoward Hinnant    if (__c(*__z, *__y))           // if y > z
36673e519524SHoward Hinnant    {
36683e519524SHoward Hinnant        swap(*__y, *__z);          // x <= y && y < z
36693e519524SHoward Hinnant        __r = 2;
36703e519524SHoward Hinnant    }
36713e519524SHoward Hinnant    return __r;
36723e519524SHoward Hinnant}                                  // x <= y && y <= z
36733e519524SHoward Hinnant
36743e519524SHoward Hinnant// stable, 3-6 compares, 0-5 swaps
36753e519524SHoward Hinnant
36763e519524SHoward Hinnanttemplate <class _Compare, class _ForwardIterator>
36773e519524SHoward Hinnantunsigned
36783e519524SHoward Hinnant__sort4(_ForwardIterator __x1, _ForwardIterator __x2, _ForwardIterator __x3,
36793e519524SHoward Hinnant            _ForwardIterator __x4, _Compare __c)
36803e519524SHoward Hinnant{
36813e519524SHoward Hinnant    unsigned __r = __sort3<_Compare>(__x1, __x2, __x3, __c);
36823e519524SHoward Hinnant    if (__c(*__x4, *__x3))
36833e519524SHoward Hinnant    {
36843e519524SHoward Hinnant        swap(*__x3, *__x4);
36853e519524SHoward Hinnant        ++__r;
36863e519524SHoward Hinnant        if (__c(*__x3, *__x2))
36873e519524SHoward Hinnant        {
36883e519524SHoward Hinnant            swap(*__x2, *__x3);
36893e519524SHoward Hinnant            ++__r;
36903e519524SHoward Hinnant            if (__c(*__x2, *__x1))
36913e519524SHoward Hinnant            {
36923e519524SHoward Hinnant                swap(*__x1, *__x2);
36933e519524SHoward Hinnant                ++__r;
36943e519524SHoward Hinnant            }
36953e519524SHoward Hinnant        }
36963e519524SHoward Hinnant    }
36973e519524SHoward Hinnant    return __r;
36983e519524SHoward Hinnant}
36993e519524SHoward Hinnant
37003e519524SHoward Hinnant// stable, 4-10 compares, 0-9 swaps
37013e519524SHoward Hinnant
37023e519524SHoward Hinnanttemplate <class _Compare, class _ForwardIterator>
3703835140a4SLouis Dionne_LIBCPP_HIDDEN
37043e519524SHoward Hinnantunsigned
37053e519524SHoward Hinnant__sort5(_ForwardIterator __x1, _ForwardIterator __x2, _ForwardIterator __x3,
37063e519524SHoward Hinnant            _ForwardIterator __x4, _ForwardIterator __x5, _Compare __c)
37073e519524SHoward Hinnant{
37083e519524SHoward Hinnant    unsigned __r = __sort4<_Compare>(__x1, __x2, __x3, __x4, __c);
37093e519524SHoward Hinnant    if (__c(*__x5, *__x4))
37103e519524SHoward Hinnant    {
37113e519524SHoward Hinnant        swap(*__x4, *__x5);
37123e519524SHoward Hinnant        ++__r;
37133e519524SHoward Hinnant        if (__c(*__x4, *__x3))
37143e519524SHoward Hinnant        {
37153e519524SHoward Hinnant            swap(*__x3, *__x4);
37163e519524SHoward Hinnant            ++__r;
37173e519524SHoward Hinnant            if (__c(*__x3, *__x2))
37183e519524SHoward Hinnant            {
37193e519524SHoward Hinnant                swap(*__x2, *__x3);
37203e519524SHoward Hinnant                ++__r;
37213e519524SHoward Hinnant                if (__c(*__x2, *__x1))
37223e519524SHoward Hinnant                {
37233e519524SHoward Hinnant                    swap(*__x1, *__x2);
37243e519524SHoward Hinnant                    ++__r;
37253e519524SHoward Hinnant                }
37263e519524SHoward Hinnant            }
37273e519524SHoward Hinnant        }
37283e519524SHoward Hinnant    }
37293e519524SHoward Hinnant    return __r;
37303e519524SHoward Hinnant}
37313e519524SHoward Hinnant
37323e519524SHoward Hinnant// Assumes size > 0
37333e519524SHoward Hinnanttemplate <class _Compare, class _BirdirectionalIterator>
37343e519524SHoward Hinnantvoid
37353e519524SHoward Hinnant__selection_sort(_BirdirectionalIterator __first, _BirdirectionalIterator __last, _Compare __comp)
37363e519524SHoward Hinnant{
37373e519524SHoward Hinnant    _BirdirectionalIterator __lm1 = __last;
37383e519524SHoward Hinnant    for (--__lm1; __first != __lm1; ++__first)
37393e519524SHoward Hinnant    {
3740ce48a113SHoward Hinnant        _BirdirectionalIterator __i = _VSTD::min_element<_BirdirectionalIterator,
37413e519524SHoward Hinnant                                                        typename add_lvalue_reference<_Compare>::type>
37423e519524SHoward Hinnant                                                       (__first, __last, __comp);
37433e519524SHoward Hinnant        if (__i != __first)
37443e519524SHoward Hinnant            swap(*__first, *__i);
37453e519524SHoward Hinnant    }
37463e519524SHoward Hinnant}
37473e519524SHoward Hinnant
37483e519524SHoward Hinnanttemplate <class _Compare, class _BirdirectionalIterator>
37493e519524SHoward Hinnantvoid
37503e519524SHoward Hinnant__insertion_sort(_BirdirectionalIterator __first, _BirdirectionalIterator __last, _Compare __comp)
37513e519524SHoward Hinnant{
37523e519524SHoward Hinnant    typedef typename iterator_traits<_BirdirectionalIterator>::value_type value_type;
37533e519524SHoward Hinnant    if (__first != __last)
37543e519524SHoward Hinnant    {
37553e519524SHoward Hinnant        _BirdirectionalIterator __i = __first;
37563e519524SHoward Hinnant        for (++__i; __i != __last; ++__i)
37573e519524SHoward Hinnant        {
37583e519524SHoward Hinnant            _BirdirectionalIterator __j = __i;
3759ce48a113SHoward Hinnant            value_type __t(_VSTD::move(*__j));
37603e519524SHoward Hinnant            for (_BirdirectionalIterator __k = __i; __k != __first && __comp(__t,  *--__k); --__j)
3761ce48a113SHoward Hinnant                *__j = _VSTD::move(*__k);
3762ce48a113SHoward Hinnant            *__j = _VSTD::move(__t);
37633e519524SHoward Hinnant        }
37643e519524SHoward Hinnant    }
37653e519524SHoward Hinnant}
37663e519524SHoward Hinnant
37673e519524SHoward Hinnanttemplate <class _Compare, class _RandomAccessIterator>
37683e519524SHoward Hinnantvoid
37693e519524SHoward Hinnant__insertion_sort_3(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
37703e519524SHoward Hinnant{
37713e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
37723e519524SHoward Hinnant    _RandomAccessIterator __j = __first+2;
37733e519524SHoward Hinnant    __sort3<_Compare>(__first, __first+1, __j, __comp);
37743e519524SHoward Hinnant    for (_RandomAccessIterator __i = __j+1; __i != __last; ++__i)
37753e519524SHoward Hinnant    {
37763e519524SHoward Hinnant        if (__comp(*__i, *__j))
37773e519524SHoward Hinnant        {
3778ce48a113SHoward Hinnant            value_type __t(_VSTD::move(*__i));
37793e519524SHoward Hinnant            _RandomAccessIterator __k = __j;
37803e519524SHoward Hinnant            __j = __i;
37813e519524SHoward Hinnant            do
37823e519524SHoward Hinnant            {
3783ce48a113SHoward Hinnant                *__j = _VSTD::move(*__k);
37843e519524SHoward Hinnant                __j = __k;
37853e519524SHoward Hinnant            } while (__j != __first && __comp(__t, *--__k));
3786ce48a113SHoward Hinnant            *__j = _VSTD::move(__t);
37873e519524SHoward Hinnant        }
37883e519524SHoward Hinnant        __j = __i;
37893e519524SHoward Hinnant    }
37903e519524SHoward Hinnant}
37913e519524SHoward Hinnant
37923e519524SHoward Hinnanttemplate <class _Compare, class _RandomAccessIterator>
37933e519524SHoward Hinnantbool
37943e519524SHoward Hinnant__insertion_sort_incomplete(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
37953e519524SHoward Hinnant{
37963e519524SHoward Hinnant    switch (__last - __first)
37973e519524SHoward Hinnant    {
37983e519524SHoward Hinnant    case 0:
37993e519524SHoward Hinnant    case 1:
38003e519524SHoward Hinnant        return true;
38013e519524SHoward Hinnant    case 2:
38023e519524SHoward Hinnant        if (__comp(*--__last, *__first))
38033e519524SHoward Hinnant            swap(*__first, *__last);
38043e519524SHoward Hinnant        return true;
38053e519524SHoward Hinnant    case 3:
3806ce48a113SHoward Hinnant        _VSTD::__sort3<_Compare>(__first, __first+1, --__last, __comp);
38073e519524SHoward Hinnant        return true;
38083e519524SHoward Hinnant    case 4:
3809ce48a113SHoward Hinnant        _VSTD::__sort4<_Compare>(__first, __first+1, __first+2, --__last, __comp);
38103e519524SHoward Hinnant        return true;
38113e519524SHoward Hinnant    case 5:
3812ce48a113SHoward Hinnant        _VSTD::__sort5<_Compare>(__first, __first+1, __first+2, __first+3, --__last, __comp);
38133e519524SHoward Hinnant        return true;
38143e519524SHoward Hinnant    }
38153e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
38163e519524SHoward Hinnant    _RandomAccessIterator __j = __first+2;
38173e519524SHoward Hinnant    __sort3<_Compare>(__first, __first+1, __j, __comp);
38183e519524SHoward Hinnant    const unsigned __limit = 8;
38193e519524SHoward Hinnant    unsigned __count = 0;
38203e519524SHoward Hinnant    for (_RandomAccessIterator __i = __j+1; __i != __last; ++__i)
38213e519524SHoward Hinnant    {
38223e519524SHoward Hinnant        if (__comp(*__i, *__j))
38233e519524SHoward Hinnant        {
3824ce48a113SHoward Hinnant            value_type __t(_VSTD::move(*__i));
38253e519524SHoward Hinnant            _RandomAccessIterator __k = __j;
38263e519524SHoward Hinnant            __j = __i;
38273e519524SHoward Hinnant            do
38283e519524SHoward Hinnant            {
3829ce48a113SHoward Hinnant                *__j = _VSTD::move(*__k);
38303e519524SHoward Hinnant                __j = __k;
38313e519524SHoward Hinnant            } while (__j != __first && __comp(__t, *--__k));
3832ce48a113SHoward Hinnant            *__j = _VSTD::move(__t);
38333e519524SHoward Hinnant            if (++__count == __limit)
38343e519524SHoward Hinnant                return ++__i == __last;
38353e519524SHoward Hinnant        }
38363e519524SHoward Hinnant        __j = __i;
38373e519524SHoward Hinnant    }
38383e519524SHoward Hinnant    return true;
38393e519524SHoward Hinnant}
38403e519524SHoward Hinnant
38413e519524SHoward Hinnanttemplate <class _Compare, class _BirdirectionalIterator>
38423e519524SHoward Hinnantvoid
38433e519524SHoward Hinnant__insertion_sort_move(_BirdirectionalIterator __first1, _BirdirectionalIterator __last1,
38443e519524SHoward Hinnant                      typename iterator_traits<_BirdirectionalIterator>::value_type* __first2, _Compare __comp)
38453e519524SHoward Hinnant{
38463e519524SHoward Hinnant    typedef typename iterator_traits<_BirdirectionalIterator>::value_type value_type;
38473e519524SHoward Hinnant    if (__first1 != __last1)
38483e519524SHoward Hinnant    {
38493e519524SHoward Hinnant        __destruct_n __d(0);
38503e519524SHoward Hinnant        unique_ptr<value_type, __destruct_n&> __h(__first2, __d);
38513e519524SHoward Hinnant        value_type* __last2 = __first2;
3852ce48a113SHoward Hinnant        ::new(__last2) value_type(_VSTD::move(*__first1));
38533e519524SHoward Hinnant        __d.__incr((value_type*)0);
38543e519524SHoward Hinnant        for (++__last2; ++__first1 != __last1; ++__last2)
38553e519524SHoward Hinnant        {
38563e519524SHoward Hinnant            value_type* __j2 = __last2;
38573e519524SHoward Hinnant            value_type* __i2 = __j2;
38583e519524SHoward Hinnant            if (__comp(*__first1, *--__i2))
38593e519524SHoward Hinnant            {
3860ce48a113SHoward Hinnant                ::new(__j2) value_type(_VSTD::move(*__i2));
38613e519524SHoward Hinnant                __d.__incr((value_type*)0);
38623e519524SHoward Hinnant                for (--__j2; __i2 != __first2 && __comp(*__first1,  *--__i2); --__j2)
3863ce48a113SHoward Hinnant                    *__j2 = _VSTD::move(*__i2);
3864ce48a113SHoward Hinnant                *__j2 = _VSTD::move(*__first1);
38653e519524SHoward Hinnant            }
38663e519524SHoward Hinnant            else
38673e519524SHoward Hinnant            {
3868ce48a113SHoward Hinnant                ::new(__j2) value_type(_VSTD::move(*__first1));
38693e519524SHoward Hinnant                __d.__incr((value_type*)0);
38703e519524SHoward Hinnant            }
38713e519524SHoward Hinnant        }
38723e519524SHoward Hinnant        __h.release();
38733e519524SHoward Hinnant    }
38743e519524SHoward Hinnant}
38753e519524SHoward Hinnant
38763e519524SHoward Hinnanttemplate <class _Compare, class _RandomAccessIterator>
38773e519524SHoward Hinnantvoid
38783e519524SHoward Hinnant__sort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
38793e519524SHoward Hinnant{
38803e519524SHoward Hinnant    // _Compare is known to be a reference type
38813e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
38823e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
3883ca740483SHoward Hinnant    const difference_type __limit = is_trivially_copy_constructible<value_type>::value &&
3884ca740483SHoward Hinnant                                    is_trivially_copy_assignable<value_type>::value ? 30 : 6;
38853e519524SHoward Hinnant    while (true)
38863e519524SHoward Hinnant    {
38873e519524SHoward Hinnant    __restart:
38883e519524SHoward Hinnant        difference_type __len = __last - __first;
38893e519524SHoward Hinnant        switch (__len)
38903e519524SHoward Hinnant        {
38913e519524SHoward Hinnant        case 0:
38923e519524SHoward Hinnant        case 1:
38933e519524SHoward Hinnant            return;
38943e519524SHoward Hinnant        case 2:
38953e519524SHoward Hinnant            if (__comp(*--__last, *__first))
38963e519524SHoward Hinnant                swap(*__first, *__last);
38973e519524SHoward Hinnant            return;
38983e519524SHoward Hinnant        case 3:
3899ce48a113SHoward Hinnant            _VSTD::__sort3<_Compare>(__first, __first+1, --__last, __comp);
39003e519524SHoward Hinnant            return;
39013e519524SHoward Hinnant        case 4:
3902ce48a113SHoward Hinnant            _VSTD::__sort4<_Compare>(__first, __first+1, __first+2, --__last, __comp);
39033e519524SHoward Hinnant            return;
39043e519524SHoward Hinnant        case 5:
3905ce48a113SHoward Hinnant            _VSTD::__sort5<_Compare>(__first, __first+1, __first+2, __first+3, --__last, __comp);
39063e519524SHoward Hinnant            return;
39073e519524SHoward Hinnant        }
39083e519524SHoward Hinnant        if (__len <= __limit)
39093e519524SHoward Hinnant        {
3910ce48a113SHoward Hinnant            _VSTD::__insertion_sort_3<_Compare>(__first, __last, __comp);
39113e519524SHoward Hinnant            return;
39123e519524SHoward Hinnant        }
39133e519524SHoward Hinnant        // __len > 5
39143e519524SHoward Hinnant        _RandomAccessIterator __m = __first;
39153e519524SHoward Hinnant        _RandomAccessIterator __lm1 = __last;
39163e519524SHoward Hinnant        --__lm1;
39173e519524SHoward Hinnant        unsigned __n_swaps;
39183e519524SHoward Hinnant        {
39193e519524SHoward Hinnant        difference_type __delta;
39203e519524SHoward Hinnant        if (__len >= 1000)
39213e519524SHoward Hinnant        {
39223e519524SHoward Hinnant            __delta = __len/2;
39233e519524SHoward Hinnant            __m += __delta;
39243e519524SHoward Hinnant            __delta /= 2;
3925ce48a113SHoward Hinnant            __n_swaps = _VSTD::__sort5<_Compare>(__first, __first + __delta, __m, __m+__delta, __lm1, __comp);
39263e519524SHoward Hinnant        }
39273e519524SHoward Hinnant        else
39283e519524SHoward Hinnant        {
39293e519524SHoward Hinnant            __delta = __len/2;
39303e519524SHoward Hinnant            __m += __delta;
3931ce48a113SHoward Hinnant            __n_swaps = _VSTD::__sort3<_Compare>(__first, __m, __lm1, __comp);
39323e519524SHoward Hinnant        }
39333e519524SHoward Hinnant        }
39343e519524SHoward Hinnant        // *__m is median
39353e519524SHoward Hinnant        // partition [__first, __m) < *__m and *__m <= [__m, __last)
39363e519524SHoward Hinnant        // (this inhibits tossing elements equivalent to __m around unnecessarily)
39373e519524SHoward Hinnant        _RandomAccessIterator __i = __first;
39383e519524SHoward Hinnant        _RandomAccessIterator __j = __lm1;
39393e519524SHoward Hinnant        // j points beyond range to be tested, *__m is known to be <= *__lm1
39403e519524SHoward Hinnant        // The search going up is known to be guarded but the search coming down isn't.
39413e519524SHoward Hinnant        // Prime the downward search with a guard.
39423e519524SHoward Hinnant        if (!__comp(*__i, *__m))  // if *__first == *__m
39433e519524SHoward Hinnant        {
39443e519524SHoward Hinnant            // *__first == *__m, *__first doesn't go in first part
39453e519524SHoward Hinnant            // manually guard downward moving __j against __i
39463e519524SHoward Hinnant            while (true)
39473e519524SHoward Hinnant            {
39483e519524SHoward Hinnant                if (__i == --__j)
39493e519524SHoward Hinnant                {
39503e519524SHoward Hinnant                    // *__first == *__m, *__m <= all other elements
39513e519524SHoward Hinnant                    // Parition instead into [__first, __i) == *__first and *__first < [__i, __last)
39523e519524SHoward Hinnant                    ++__i;  // __first + 1
39533e519524SHoward Hinnant                    __j = __last;
39543e519524SHoward Hinnant                    if (!__comp(*__first, *--__j))  // we need a guard if *__first == *(__last-1)
39553e519524SHoward Hinnant                    {
39563e519524SHoward Hinnant                        while (true)
39573e519524SHoward Hinnant                        {
39583e519524SHoward Hinnant                            if (__i == __j)
39593e519524SHoward Hinnant                                return;  // [__first, __last) all equivalent elements
39603e519524SHoward Hinnant                            if (__comp(*__first, *__i))
39613e519524SHoward Hinnant                            {
39623e519524SHoward Hinnant                                swap(*__i, *__j);
39633e519524SHoward Hinnant                                ++__n_swaps;
39643e519524SHoward Hinnant                                ++__i;
39653e519524SHoward Hinnant                                break;
39663e519524SHoward Hinnant                            }
39673e519524SHoward Hinnant                            ++__i;
39683e519524SHoward Hinnant                        }
39693e519524SHoward Hinnant                    }
39703e519524SHoward Hinnant                    // [__first, __i) == *__first and *__first < [__j, __last) and __j == __last - 1
39713e519524SHoward Hinnant                    if (__i == __j)
39723e519524SHoward Hinnant                        return;
39733e519524SHoward Hinnant                    while (true)
39743e519524SHoward Hinnant                    {
39753e519524SHoward Hinnant                        while (!__comp(*__first, *__i))
39763e519524SHoward Hinnant                            ++__i;
39773e519524SHoward Hinnant                        while (__comp(*__first, *--__j))
39783e519524SHoward Hinnant                            ;
39793e519524SHoward Hinnant                        if (__i >= __j)
39803e519524SHoward Hinnant                            break;
39813e519524SHoward Hinnant                        swap(*__i, *__j);
39823e519524SHoward Hinnant                        ++__n_swaps;
39833e519524SHoward Hinnant                        ++__i;
39843e519524SHoward Hinnant                    }
39853e519524SHoward Hinnant                    // [__first, __i) == *__first and *__first < [__i, __last)
39863e519524SHoward Hinnant                    // The first part is sorted, sort the secod part
3987ce48a113SHoward Hinnant                    // _VSTD::__sort<_Compare>(__i, __last, __comp);
39883e519524SHoward Hinnant                    __first = __i;
39893e519524SHoward Hinnant                    goto __restart;
39903e519524SHoward Hinnant                }
39913e519524SHoward Hinnant                if (__comp(*__j, *__m))
39923e519524SHoward Hinnant                {
39933e519524SHoward Hinnant                    swap(*__i, *__j);
39943e519524SHoward Hinnant                    ++__n_swaps;
39953e519524SHoward Hinnant                    break;  // found guard for downward moving __j, now use unguarded partition
39963e519524SHoward Hinnant                }
39973e519524SHoward Hinnant            }
39983e519524SHoward Hinnant        }
39993e519524SHoward Hinnant        // It is known that *__i < *__m
40003e519524SHoward Hinnant        ++__i;
40013e519524SHoward Hinnant        // j points beyond range to be tested, *__m is known to be <= *__lm1
40023e519524SHoward Hinnant        // if not yet partitioned...
40033e519524SHoward Hinnant        if (__i < __j)
40043e519524SHoward Hinnant        {
40053e519524SHoward Hinnant            // known that *(__i - 1) < *__m
40063e519524SHoward Hinnant            // known that __i <= __m
40073e519524SHoward Hinnant            while (true)
40083e519524SHoward Hinnant            {
40093e519524SHoward Hinnant                // __m still guards upward moving __i
40103e519524SHoward Hinnant                while (__comp(*__i, *__m))
40113e519524SHoward Hinnant                    ++__i;
40123e519524SHoward Hinnant                // It is now known that a guard exists for downward moving __j
40133e519524SHoward Hinnant                while (!__comp(*--__j, *__m))
40143e519524SHoward Hinnant                    ;
40153e519524SHoward Hinnant                if (__i > __j)
40163e519524SHoward Hinnant                    break;
40173e519524SHoward Hinnant                swap(*__i, *__j);
40183e519524SHoward Hinnant                ++__n_swaps;
40193e519524SHoward Hinnant                // It is known that __m != __j
40203e519524SHoward Hinnant                // If __m just moved, follow it
40213e519524SHoward Hinnant                if (__m == __i)
40223e519524SHoward Hinnant                    __m = __j;
40233e519524SHoward Hinnant                ++__i;
40243e519524SHoward Hinnant            }
40253e519524SHoward Hinnant        }
40263e519524SHoward Hinnant        // [__first, __i) < *__m and *__m <= [__i, __last)
40273e519524SHoward Hinnant        if (__i != __m && __comp(*__m, *__i))
40283e519524SHoward Hinnant        {
40293e519524SHoward Hinnant            swap(*__i, *__m);
40303e519524SHoward Hinnant            ++__n_swaps;
40313e519524SHoward Hinnant        }
40323e519524SHoward Hinnant        // [__first, __i) < *__i and *__i <= [__i+1, __last)
40333e519524SHoward Hinnant        // If we were given a perfect partition, see if insertion sort is quick...
40343e519524SHoward Hinnant        if (__n_swaps == 0)
40353e519524SHoward Hinnant        {
4036ce48a113SHoward Hinnant            bool __fs = _VSTD::__insertion_sort_incomplete<_Compare>(__first, __i, __comp);
4037ce48a113SHoward Hinnant            if (_VSTD::__insertion_sort_incomplete<_Compare>(__i+1, __last, __comp))
40383e519524SHoward Hinnant            {
40393e519524SHoward Hinnant                if (__fs)
40403e519524SHoward Hinnant                    return;
40413e519524SHoward Hinnant                __last = __i;
40423e519524SHoward Hinnant                continue;
40433e519524SHoward Hinnant            }
40443e519524SHoward Hinnant            else
40453e519524SHoward Hinnant            {
40463e519524SHoward Hinnant                if (__fs)
40473e519524SHoward Hinnant                {
40483e519524SHoward Hinnant                    __first = ++__i;
40493e519524SHoward Hinnant                    continue;
40503e519524SHoward Hinnant                }
40513e519524SHoward Hinnant            }
40523e519524SHoward Hinnant        }
40533e519524SHoward Hinnant        // sort smaller range with recursive call and larger with tail recursion elimination
40543e519524SHoward Hinnant        if (__i - __first < __last - __i)
40553e519524SHoward Hinnant        {
4056ce48a113SHoward Hinnant            _VSTD::__sort<_Compare>(__first, __i, __comp);
4057ce48a113SHoward Hinnant            // _VSTD::__sort<_Compare>(__i+1, __last, __comp);
40583e519524SHoward Hinnant            __first = ++__i;
40593e519524SHoward Hinnant        }
40603e519524SHoward Hinnant        else
40613e519524SHoward Hinnant        {
4062ce48a113SHoward Hinnant            _VSTD::__sort<_Compare>(__i+1, __last, __comp);
4063ce48a113SHoward Hinnant            // _VSTD::__sort<_Compare>(__first, __i, __comp);
40643e519524SHoward Hinnant            __last = __i;
40653e519524SHoward Hinnant        }
40663e519524SHoward Hinnant    }
40673e519524SHoward Hinnant}
40683e519524SHoward Hinnant
40693e519524SHoward Hinnant// This forwarder keeps the top call and the recursive calls using the same instantiation, forcing a reference _Compare
40703e519524SHoward Hinnanttemplate <class _RandomAccessIterator, class _Compare>
40713e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
40723e519524SHoward Hinnantvoid
40733e519524SHoward Hinnantsort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
40743e519524SHoward Hinnant{
4075145afa17SHoward Hinnant#ifdef _LIBCPP_DEBUG
40763e519524SHoward Hinnant    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
40773e519524SHoward Hinnant    __debug_less<_Compare> __c(__comp);
40783e519524SHoward Hinnant    __sort<_Comp_ref>(__first, __last, __c);
4079145afa17SHoward Hinnant#else  // _LIBCPP_DEBUG
40803e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
40813e519524SHoward Hinnant    __sort<_Comp_ref>(__first, __last, __comp);
4082145afa17SHoward Hinnant#endif  // _LIBCPP_DEBUG
40833e519524SHoward Hinnant}
40843e519524SHoward Hinnant
40853e519524SHoward Hinnanttemplate <class _RandomAccessIterator>
40863e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
40873e519524SHoward Hinnantvoid
40883e519524SHoward Hinnantsort(_RandomAccessIterator __first, _RandomAccessIterator __last)
40893e519524SHoward Hinnant{
4090ce48a113SHoward Hinnant    _VSTD::sort(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
40913e519524SHoward Hinnant}
40923e519524SHoward Hinnant
40933e519524SHoward Hinnanttemplate <class _Tp>
40943e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
40953e519524SHoward Hinnantvoid
40963e519524SHoward Hinnantsort(_Tp** __first, _Tp** __last)
40973e519524SHoward Hinnant{
4098ce48a113SHoward Hinnant    _VSTD::sort((size_t*)__first, (size_t*)__last, __less<size_t>());
40993e519524SHoward Hinnant}
41003e519524SHoward Hinnant
41013e519524SHoward Hinnanttemplate <class _Tp>
41023e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
41033e519524SHoward Hinnantvoid
41043e519524SHoward Hinnantsort(__wrap_iter<_Tp*> __first, __wrap_iter<_Tp*> __last)
41053e519524SHoward Hinnant{
4106ce48a113SHoward Hinnant    _VSTD::sort(__first.base(), __last.base());
41073e519524SHoward Hinnant}
41083e519524SHoward Hinnant
4109f554add5SHoward Hinnanttemplate <class _Tp, class _Compare>
4110f554add5SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
4111f554add5SHoward Hinnantvoid
4112f554add5SHoward Hinnantsort(__wrap_iter<_Tp*> __first, __wrap_iter<_Tp*> __last, _Compare __comp)
4113f554add5SHoward Hinnant{
4114f554add5SHoward Hinnant    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
4115f554add5SHoward Hinnant    _VSTD::sort<_Tp*, _Comp_ref>(__first.base(), __last.base(), __comp);
4116f554add5SHoward Hinnant}
4117f554add5SHoward Hinnant
4118f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<char>&, char*>(char*, char*, __less<char>&))
4119f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<wchar_t>&, wchar_t*>(wchar_t*, wchar_t*, __less<wchar_t>&))
4120f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<signed char>&, signed char*>(signed char*, signed char*, __less<signed char>&))
4121f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<unsigned char>&, unsigned char*>(unsigned char*, unsigned char*, __less<unsigned char>&))
4122f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<short>&, short*>(short*, short*, __less<short>&))
4123f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<unsigned short>&, unsigned short*>(unsigned short*, unsigned short*, __less<unsigned short>&))
4124f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<int>&, int*>(int*, int*, __less<int>&))
4125f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<unsigned>&, unsigned*>(unsigned*, unsigned*, __less<unsigned>&))
4126f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<long>&, long*>(long*, long*, __less<long>&))
4127f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<unsigned long>&, unsigned long*>(unsigned long*, unsigned long*, __less<unsigned long>&))
4128f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<long long>&, long long*>(long long*, long long*, __less<long long>&))
4129f0544c20SHoward 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>&))
4130f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<float>&, float*>(float*, float*, __less<float>&))
4131f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<double>&, double*>(double*, double*, __less<double>&))
4132f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<long double>&, long double*>(long double*, long double*, __less<long double>&))
41333e519524SHoward Hinnant
4134f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<char>&, char*>(char*, char*, __less<char>&))
4135f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<wchar_t>&, wchar_t*>(wchar_t*, wchar_t*, __less<wchar_t>&))
4136f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<signed char>&, signed char*>(signed char*, signed char*, __less<signed char>&))
4137f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<unsigned char>&, unsigned char*>(unsigned char*, unsigned char*, __less<unsigned char>&))
4138f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<short>&, short*>(short*, short*, __less<short>&))
4139f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<unsigned short>&, unsigned short*>(unsigned short*, unsigned short*, __less<unsigned short>&))
4140f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<int>&, int*>(int*, int*, __less<int>&))
4141f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<unsigned>&, unsigned*>(unsigned*, unsigned*, __less<unsigned>&))
4142f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<long>&, long*>(long*, long*, __less<long>&))
4143f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<unsigned long>&, unsigned long*>(unsigned long*, unsigned long*, __less<unsigned long>&))
4144f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<long long>&, long long*>(long long*, long long*, __less<long long>&))
4145f0544c20SHoward 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>&))
4146f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<float>&, float*>(float*, float*, __less<float>&))
4147f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<double>&, double*>(double*, double*, __less<double>&))
4148f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<long double>&, long double*>(long double*, long double*, __less<long double>&))
41493e519524SHoward Hinnant
4150f0544c20SHoward 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>&))
41513e519524SHoward Hinnant
41523e519524SHoward Hinnant// lower_bound
41533e519524SHoward Hinnant
41543e519524SHoward Hinnanttemplate <class _Compare, class _ForwardIterator, class _Tp>
4155d57c03ddSMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
4156e4383379SHoward Hinnant__lower_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
41573e519524SHoward Hinnant{
41583e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator>::difference_type difference_type;
4159ce48a113SHoward Hinnant    difference_type __len = _VSTD::distance(__first, __last);
41603e519524SHoward Hinnant    while (__len != 0)
41613e519524SHoward Hinnant    {
416204695a75SLouis Dionne        difference_type __l2 = _VSTD::__half_positive(__len);
41633e519524SHoward Hinnant        _ForwardIterator __m = __first;
4164ce48a113SHoward Hinnant        _VSTD::advance(__m, __l2);
4165e4383379SHoward Hinnant        if (__comp(*__m, __value_))
41663e519524SHoward Hinnant        {
41673e519524SHoward Hinnant            __first = ++__m;
41683e519524SHoward Hinnant            __len -= __l2 + 1;
41693e519524SHoward Hinnant        }
41703e519524SHoward Hinnant        else
41713e519524SHoward Hinnant            __len = __l2;
41723e519524SHoward Hinnant    }
41733e519524SHoward Hinnant    return __first;
41743e519524SHoward Hinnant}
41753e519524SHoward Hinnant
41763e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Tp, class _Compare>
4177*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
4178*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
41793e519524SHoward Hinnant_ForwardIterator
4180e4383379SHoward Hinnantlower_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
41813e519524SHoward Hinnant{
41823e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
4183e4383379SHoward Hinnant    return __lower_bound<_Comp_ref>(__first, __last, __value_, __comp);
41843e519524SHoward Hinnant}
41853e519524SHoward Hinnant
41863e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Tp>
4187*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
4188*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
41893e519524SHoward Hinnant_ForwardIterator
4190e4383379SHoward Hinnantlower_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_)
41913e519524SHoward Hinnant{
4192e4383379SHoward Hinnant    return _VSTD::lower_bound(__first, __last, __value_,
41933e519524SHoward Hinnant                             __less<typename iterator_traits<_ForwardIterator>::value_type, _Tp>());
41943e519524SHoward Hinnant}
41953e519524SHoward Hinnant
41963e519524SHoward Hinnant// upper_bound
41973e519524SHoward Hinnant
41983e519524SHoward Hinnanttemplate <class _Compare, class _ForwardIterator, class _Tp>
4199d57c03ddSMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
4200e4383379SHoward Hinnant__upper_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
42013e519524SHoward Hinnant{
42023e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator>::difference_type difference_type;
4203ce48a113SHoward Hinnant    difference_type __len = _VSTD::distance(__first, __last);
42043e519524SHoward Hinnant    while (__len != 0)
42053e519524SHoward Hinnant    {
420604695a75SLouis Dionne        difference_type __l2 = _VSTD::__half_positive(__len);
42073e519524SHoward Hinnant        _ForwardIterator __m = __first;
4208ce48a113SHoward Hinnant        _VSTD::advance(__m, __l2);
4209e4383379SHoward Hinnant        if (__comp(__value_, *__m))
42103e519524SHoward Hinnant            __len = __l2;
42113e519524SHoward Hinnant        else
42123e519524SHoward Hinnant        {
42133e519524SHoward Hinnant            __first = ++__m;
42143e519524SHoward Hinnant            __len -= __l2 + 1;
42153e519524SHoward Hinnant        }
42163e519524SHoward Hinnant    }
42173e519524SHoward Hinnant    return __first;
42183e519524SHoward Hinnant}
42193e519524SHoward Hinnant
42203e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Tp, class _Compare>
4221*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
4222*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
42233e519524SHoward Hinnant_ForwardIterator
4224e4383379SHoward Hinnantupper_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
42253e519524SHoward Hinnant{
42263e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
4227e4383379SHoward Hinnant    return __upper_bound<_Comp_ref>(__first, __last, __value_, __comp);
42283e519524SHoward Hinnant}
42293e519524SHoward Hinnant
42303e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Tp>
4231*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
4232*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
42333e519524SHoward Hinnant_ForwardIterator
4234e4383379SHoward Hinnantupper_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_)
42353e519524SHoward Hinnant{
4236e4383379SHoward Hinnant    return _VSTD::upper_bound(__first, __last, __value_,
42373e519524SHoward Hinnant                             __less<_Tp, typename iterator_traits<_ForwardIterator>::value_type>());
42383e519524SHoward Hinnant}
42393e519524SHoward Hinnant
42403e519524SHoward Hinnant// equal_range
42413e519524SHoward Hinnant
42423e519524SHoward Hinnanttemplate <class _Compare, class _ForwardIterator, class _Tp>
4243d57c03ddSMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 pair<_ForwardIterator, _ForwardIterator>
4244e4383379SHoward Hinnant__equal_range(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
42453e519524SHoward Hinnant{
42463e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator>::difference_type difference_type;
4247ce48a113SHoward Hinnant    difference_type __len = _VSTD::distance(__first, __last);
42483e519524SHoward Hinnant    while (__len != 0)
42493e519524SHoward Hinnant    {
425004695a75SLouis Dionne        difference_type __l2 = _VSTD::__half_positive(__len);
42513e519524SHoward Hinnant        _ForwardIterator __m = __first;
4252ce48a113SHoward Hinnant        _VSTD::advance(__m, __l2);
4253e4383379SHoward Hinnant        if (__comp(*__m, __value_))
42543e519524SHoward Hinnant        {
42553e519524SHoward Hinnant            __first = ++__m;
42563e519524SHoward Hinnant            __len -= __l2 + 1;
42573e519524SHoward Hinnant        }
4258e4383379SHoward Hinnant        else if (__comp(__value_, *__m))
42593e519524SHoward Hinnant        {
42603e519524SHoward Hinnant            __last = __m;
42613e519524SHoward Hinnant            __len = __l2;
42623e519524SHoward Hinnant        }
42633e519524SHoward Hinnant        else
42643e519524SHoward Hinnant        {
42653e519524SHoward Hinnant            _ForwardIterator __mp1 = __m;
42663e519524SHoward Hinnant            return pair<_ForwardIterator, _ForwardIterator>
42673e519524SHoward Hinnant                   (
4268e4383379SHoward Hinnant                      __lower_bound<_Compare>(__first, __m, __value_, __comp),
4269e4383379SHoward Hinnant                      __upper_bound<_Compare>(++__mp1, __last, __value_, __comp)
42703e519524SHoward Hinnant                   );
42713e519524SHoward Hinnant        }
42723e519524SHoward Hinnant    }
42733e519524SHoward Hinnant    return pair<_ForwardIterator, _ForwardIterator>(__first, __first);
42743e519524SHoward Hinnant}
42753e519524SHoward Hinnant
42763e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Tp, class _Compare>
4277*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
4278*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
42793e519524SHoward Hinnantpair<_ForwardIterator, _ForwardIterator>
4280e4383379SHoward Hinnantequal_range(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
42813e519524SHoward Hinnant{
4282145afa17SHoward Hinnant#ifdef _LIBCPP_DEBUG
42833e519524SHoward Hinnant    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
42843e519524SHoward Hinnant    __debug_less<_Compare> __c(__comp);
4285e4383379SHoward Hinnant    return __equal_range<_Comp_ref>(__first, __last, __value_, __c);
4286145afa17SHoward Hinnant#else  // _LIBCPP_DEBUG
42873e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
4288e4383379SHoward Hinnant    return __equal_range<_Comp_ref>(__first, __last, __value_, __comp);
4289145afa17SHoward Hinnant#endif  // _LIBCPP_DEBUG
42903e519524SHoward Hinnant}
42913e519524SHoward Hinnant
42923e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Tp>
4293*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
4294*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
42953e519524SHoward Hinnantpair<_ForwardIterator, _ForwardIterator>
4296e4383379SHoward Hinnantequal_range(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_)
42973e519524SHoward Hinnant{
4298e4383379SHoward Hinnant    return _VSTD::equal_range(__first, __last, __value_,
42993e519524SHoward Hinnant                             __less<typename iterator_traits<_ForwardIterator>::value_type, _Tp>());
43003e519524SHoward Hinnant}
43013e519524SHoward Hinnant
43023e519524SHoward Hinnant// binary_search
43033e519524SHoward Hinnant
43043e519524SHoward Hinnanttemplate <class _Compare, class _ForwardIterator, class _Tp>
4305d57c03ddSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
43063e519524SHoward Hinnantbool
4307e4383379SHoward Hinnant__binary_search(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
43083e519524SHoward Hinnant{
4309e4383379SHoward Hinnant    __first = __lower_bound<_Compare>(__first, __last, __value_, __comp);
4310e4383379SHoward Hinnant    return __first != __last && !__comp(__value_, *__first);
43113e519524SHoward Hinnant}
43123e519524SHoward Hinnant
43133e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Tp, class _Compare>
4314*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
4315*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
43163e519524SHoward Hinnantbool
4317e4383379SHoward Hinnantbinary_search(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
43183e519524SHoward Hinnant{
4319145afa17SHoward Hinnant#ifdef _LIBCPP_DEBUG
43203e519524SHoward Hinnant    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
43213e519524SHoward Hinnant    __debug_less<_Compare> __c(__comp);
4322e4383379SHoward Hinnant    return __binary_search<_Comp_ref>(__first, __last, __value_, __c);
4323145afa17SHoward Hinnant#else  // _LIBCPP_DEBUG
43243e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
4325e4383379SHoward Hinnant    return __binary_search<_Comp_ref>(__first, __last, __value_, __comp);
4326145afa17SHoward Hinnant#endif  // _LIBCPP_DEBUG
43273e519524SHoward Hinnant}
43283e519524SHoward Hinnant
43293e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Tp>
4330*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
4331*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
43323e519524SHoward Hinnantbool
4333e4383379SHoward Hinnantbinary_search(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_)
43343e519524SHoward Hinnant{
4335e4383379SHoward Hinnant    return _VSTD::binary_search(__first, __last, __value_,
43363e519524SHoward Hinnant                             __less<typename iterator_traits<_ForwardIterator>::value_type, _Tp>());
43373e519524SHoward Hinnant}
43383e519524SHoward Hinnant
43393e519524SHoward Hinnant// merge
43403e519524SHoward Hinnant
43413e519524SHoward Hinnanttemplate <class _Compare, class _InputIterator1, class _InputIterator2, class _OutputIterator>
43423e519524SHoward Hinnant_OutputIterator
43433e519524SHoward Hinnant__merge(_InputIterator1 __first1, _InputIterator1 __last1,
43443e519524SHoward Hinnant        _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
43453e519524SHoward Hinnant{
43463e519524SHoward Hinnant    for (; __first1 != __last1; ++__result)
43473e519524SHoward Hinnant    {
43483e519524SHoward Hinnant        if (__first2 == __last2)
4349ce48a113SHoward Hinnant            return _VSTD::copy(__first1, __last1, __result);
43503e519524SHoward Hinnant        if (__comp(*__first2, *__first1))
43513e519524SHoward Hinnant        {
43523e519524SHoward Hinnant            *__result = *__first2;
43533e519524SHoward Hinnant            ++__first2;
43543e519524SHoward Hinnant        }
43553e519524SHoward Hinnant        else
43563e519524SHoward Hinnant        {
43573e519524SHoward Hinnant            *__result = *__first1;
43583e519524SHoward Hinnant            ++__first1;
43593e519524SHoward Hinnant        }
43603e519524SHoward Hinnant    }
4361ce48a113SHoward Hinnant    return _VSTD::copy(__first2, __last2, __result);
43623e519524SHoward Hinnant}
43633e519524SHoward Hinnant
43643e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
43653e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
43663e519524SHoward Hinnant_OutputIterator
43673e519524SHoward Hinnantmerge(_InputIterator1 __first1, _InputIterator1 __last1,
43683e519524SHoward Hinnant      _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
43693e519524SHoward Hinnant{
4370145afa17SHoward Hinnant#ifdef _LIBCPP_DEBUG
43713e519524SHoward Hinnant    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
43723e519524SHoward Hinnant    __debug_less<_Compare> __c(__comp);
4373ce48a113SHoward Hinnant    return _VSTD::__merge<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __c);
4374145afa17SHoward Hinnant#else  // _LIBCPP_DEBUG
43753e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
4376ce48a113SHoward Hinnant    return _VSTD::__merge<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __comp);
4377145afa17SHoward Hinnant#endif  // _LIBCPP_DEBUG
43783e519524SHoward Hinnant}
43793e519524SHoward Hinnant
43803e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _OutputIterator>
43813e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
43823e519524SHoward Hinnant_OutputIterator
43833e519524SHoward Hinnantmerge(_InputIterator1 __first1, _InputIterator1 __last1,
43843e519524SHoward Hinnant      _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result)
43853e519524SHoward Hinnant{
43863e519524SHoward Hinnant    typedef typename iterator_traits<_InputIterator1>::value_type __v1;
43873e519524SHoward Hinnant    typedef typename iterator_traits<_InputIterator2>::value_type __v2;
43883e519524SHoward Hinnant    return merge(__first1, __last1, __first2, __last2, __result, __less<__v1, __v2>());
43893e519524SHoward Hinnant}
43903e519524SHoward Hinnant
43913e519524SHoward Hinnant// inplace_merge
43923e519524SHoward Hinnant
4393adfdae18SMarshall Clowtemplate <class _Compare, class _InputIterator1, class _InputIterator2,
4394adfdae18SMarshall Clow          class _OutputIterator>
4395adfdae18SMarshall Clowvoid __half_inplace_merge(_InputIterator1 __first1, _InputIterator1 __last1,
4396adfdae18SMarshall Clow                          _InputIterator2 __first2, _InputIterator2 __last2,
4397adfdae18SMarshall Clow                          _OutputIterator __result, _Compare __comp)
4398adfdae18SMarshall Clow{
4399adfdae18SMarshall Clow    for (; __first1 != __last1; ++__result)
4400adfdae18SMarshall Clow    {
4401adfdae18SMarshall Clow        if (__first2 == __last2)
4402adfdae18SMarshall Clow        {
4403adfdae18SMarshall Clow            _VSTD::move(__first1, __last1, __result);
4404adfdae18SMarshall Clow            return;
4405adfdae18SMarshall Clow        }
4406adfdae18SMarshall Clow
4407adfdae18SMarshall Clow        if (__comp(*__first2, *__first1))
4408adfdae18SMarshall Clow        {
4409adfdae18SMarshall Clow            *__result = _VSTD::move(*__first2);
4410adfdae18SMarshall Clow            ++__first2;
4411adfdae18SMarshall Clow        }
4412adfdae18SMarshall Clow        else
4413adfdae18SMarshall Clow        {
4414adfdae18SMarshall Clow            *__result = _VSTD::move(*__first1);
4415adfdae18SMarshall Clow            ++__first1;
4416adfdae18SMarshall Clow        }
4417adfdae18SMarshall Clow    }
4418adfdae18SMarshall Clow    // __first2 through __last2 are already in the right spot.
4419adfdae18SMarshall Clow}
4420adfdae18SMarshall Clow
44213e519524SHoward Hinnanttemplate <class _Compare, class _BidirectionalIterator>
44223e519524SHoward Hinnantvoid
44233e519524SHoward Hinnant__buffered_inplace_merge(_BidirectionalIterator __first, _BidirectionalIterator __middle, _BidirectionalIterator __last,
44243e519524SHoward Hinnant                _Compare __comp, typename iterator_traits<_BidirectionalIterator>::difference_type __len1,
44253e519524SHoward Hinnant                                 typename iterator_traits<_BidirectionalIterator>::difference_type __len2,
44263e519524SHoward Hinnant                typename iterator_traits<_BidirectionalIterator>::value_type* __buff)
44273e519524SHoward Hinnant{
44283e519524SHoward Hinnant    typedef typename iterator_traits<_BidirectionalIterator>::value_type value_type;
44293e519524SHoward Hinnant    __destruct_n __d(0);
44303e519524SHoward Hinnant    unique_ptr<value_type, __destruct_n&> __h2(__buff, __d);
44313e519524SHoward Hinnant    if (__len1 <= __len2)
44323e519524SHoward Hinnant    {
44333e519524SHoward Hinnant        value_type* __p = __buff;
4434910285b2SEric Fiselier        for (_BidirectionalIterator __i = __first; __i != __middle; __d.__incr((value_type*)0), (void) ++__i, ++__p)
4435ce48a113SHoward Hinnant            ::new(__p) value_type(_VSTD::move(*__i));
4436adfdae18SMarshall Clow        __half_inplace_merge(__buff, __p, __middle, __last, __first, __comp);
44373e519524SHoward Hinnant    }
44383e519524SHoward Hinnant    else
44393e519524SHoward Hinnant    {
44403e519524SHoward Hinnant        value_type* __p = __buff;
4441910285b2SEric Fiselier        for (_BidirectionalIterator __i = __middle; __i != __last; __d.__incr((value_type*)0), (void) ++__i, ++__p)
4442ce48a113SHoward Hinnant            ::new(__p) value_type(_VSTD::move(*__i));
44433e519524SHoward Hinnant        typedef reverse_iterator<_BidirectionalIterator> _RBi;
44443e519524SHoward Hinnant        typedef reverse_iterator<value_type*> _Rv;
4445adfdae18SMarshall Clow        __half_inplace_merge(_Rv(__p), _Rv(__buff),
4446adfdae18SMarshall Clow                             _RBi(__middle), _RBi(__first),
4447a763b36fSMarshall Clow                             _RBi(__last), __invert<_Compare>(__comp));
44483e519524SHoward Hinnant    }
44493e519524SHoward Hinnant}
44503e519524SHoward Hinnant
44513e519524SHoward Hinnanttemplate <class _Compare, class _BidirectionalIterator>
44523e519524SHoward Hinnantvoid
44533e519524SHoward Hinnant__inplace_merge(_BidirectionalIterator __first, _BidirectionalIterator __middle, _BidirectionalIterator __last,
44543e519524SHoward Hinnant                _Compare __comp, typename iterator_traits<_BidirectionalIterator>::difference_type __len1,
44553e519524SHoward Hinnant                                 typename iterator_traits<_BidirectionalIterator>::difference_type __len2,
44563e519524SHoward Hinnant                typename iterator_traits<_BidirectionalIterator>::value_type* __buff, ptrdiff_t __buff_size)
44573e519524SHoward Hinnant{
44583e519524SHoward Hinnant    typedef typename iterator_traits<_BidirectionalIterator>::difference_type difference_type;
44593e519524SHoward Hinnant    while (true)
44603e519524SHoward Hinnant    {
44613e519524SHoward Hinnant        // if __middle == __last, we're done
44623e519524SHoward Hinnant        if (__len2 == 0)
44633e519524SHoward Hinnant            return;
4464526e0929SMarshall Clow        if (__len1 <= __buff_size || __len2 <= __buff_size)
4465526e0929SMarshall Clow            return __buffered_inplace_merge<_Compare>
4466526e0929SMarshall Clow                   (__first, __middle, __last, __comp, __len1, __len2, __buff);
44673e519524SHoward Hinnant        // shrink [__first, __middle) as much as possible (with no moves), returning if it shrinks to 0
4468910285b2SEric Fiselier        for (; true; ++__first, (void) --__len1)
44693e519524SHoward Hinnant        {
44703e519524SHoward Hinnant            if (__len1 == 0)
44713e519524SHoward Hinnant                return;
44723e519524SHoward Hinnant            if (__comp(*__middle, *__first))
44733e519524SHoward Hinnant                break;
44743e519524SHoward Hinnant        }
44753e519524SHoward Hinnant        // __first < __middle < __last
44763e519524SHoward Hinnant        // *__first > *__middle
44773e519524SHoward Hinnant        // partition [__first, __m1) [__m1, __middle) [__middle, __m2) [__m2, __last) such that
44783e519524SHoward Hinnant        //     all elements in:
44793e519524SHoward Hinnant        //         [__first, __m1)  <= [__middle, __m2)
44803e519524SHoward Hinnant        //         [__middle, __m2) <  [__m1, __middle)
44813e519524SHoward Hinnant        //         [__m1, __middle) <= [__m2, __last)
44823e519524SHoward Hinnant        //     and __m1 or __m2 is in the middle of its range
44833e519524SHoward Hinnant        _BidirectionalIterator __m1;  // "median" of [__first, __middle)
44843e519524SHoward Hinnant        _BidirectionalIterator __m2;  // "median" of [__middle, __last)
44853e519524SHoward Hinnant        difference_type __len11;      // distance(__first, __m1)
44863e519524SHoward Hinnant        difference_type __len21;      // distance(__middle, __m2)
44873e519524SHoward Hinnant        // binary search smaller range
44883e519524SHoward Hinnant        if (__len1 < __len2)
44893e519524SHoward Hinnant        {   // __len >= 1, __len2 >= 2
44903e519524SHoward Hinnant            __len21 = __len2 / 2;
44913e519524SHoward Hinnant            __m2 = __middle;
4492ce48a113SHoward Hinnant            _VSTD::advance(__m2, __len21);
44933e519524SHoward Hinnant            __m1 = __upper_bound<_Compare>(__first, __middle, *__m2, __comp);
4494ce48a113SHoward Hinnant            __len11 = _VSTD::distance(__first, __m1);
44953e519524SHoward Hinnant        }
44963e519524SHoward Hinnant        else
44973e519524SHoward Hinnant        {
44983e519524SHoward Hinnant            if (__len1 == 1)
44993e519524SHoward Hinnant            {   // __len1 >= __len2 && __len2 > 0, therefore __len2 == 1
45003e519524SHoward Hinnant                // It is known *__first > *__middle
45013e519524SHoward Hinnant                swap(*__first, *__middle);
45023e519524SHoward Hinnant                return;
45033e519524SHoward Hinnant            }
45043e519524SHoward Hinnant            // __len1 >= 2, __len2 >= 1
45053e519524SHoward Hinnant            __len11 = __len1 / 2;
45063e519524SHoward Hinnant            __m1 = __first;
4507ce48a113SHoward Hinnant            _VSTD::advance(__m1, __len11);
45083e519524SHoward Hinnant            __m2 = __lower_bound<_Compare>(__middle, __last, *__m1, __comp);
4509ce48a113SHoward Hinnant            __len21 = _VSTD::distance(__middle, __m2);
45103e519524SHoward Hinnant        }
45113e519524SHoward Hinnant        difference_type __len12 = __len1 - __len11;  // distance(__m1, __middle)
45123e519524SHoward Hinnant        difference_type __len22 = __len2 - __len21;  // distance(__m2, __last)
45133e519524SHoward Hinnant        // [__first, __m1) [__m1, __middle) [__middle, __m2) [__m2, __last)
45143e519524SHoward Hinnant        // swap middle two partitions
4515ce48a113SHoward Hinnant        __middle = _VSTD::rotate(__m1, __middle, __m2);
45163e519524SHoward Hinnant        // __len12 and __len21 now have swapped meanings
45173e519524SHoward Hinnant        // merge smaller range with recurisve call and larger with tail recursion elimination
45183e519524SHoward Hinnant        if (__len11 + __len21 < __len12 + __len22)
45193e519524SHoward Hinnant        {
45203e519524SHoward Hinnant            __inplace_merge<_Compare>(__first, __m1, __middle, __comp, __len11, __len21, __buff, __buff_size);
45213e519524SHoward Hinnant//          __inplace_merge<_Compare>(__middle, __m2, __last, __comp, __len12, __len22, __buff, __buff_size);
45223e519524SHoward Hinnant            __first = __middle;
45233e519524SHoward Hinnant            __middle = __m2;
45243e519524SHoward Hinnant            __len1 = __len12;
45253e519524SHoward Hinnant            __len2 = __len22;
45263e519524SHoward Hinnant        }
45273e519524SHoward Hinnant        else
45283e519524SHoward Hinnant        {
45293e519524SHoward Hinnant            __inplace_merge<_Compare>(__middle, __m2, __last, __comp, __len12, __len22, __buff, __buff_size);
45303e519524SHoward Hinnant//          __inplace_merge<_Compare>(__first, __m1, __middle, __comp, __len11, __len21, __buff, __buff_size);
45313e519524SHoward Hinnant            __last = __middle;
45323e519524SHoward Hinnant            __middle = __m1;
45333e519524SHoward Hinnant            __len1 = __len11;
45343e519524SHoward Hinnant            __len2 = __len21;
45353e519524SHoward Hinnant        }
45363e519524SHoward Hinnant    }
45373e519524SHoward Hinnant}
45383e519524SHoward Hinnant
45393e519524SHoward Hinnanttemplate <class _BidirectionalIterator, class _Compare>
45403e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
45413e519524SHoward Hinnantvoid
45423e519524SHoward Hinnantinplace_merge(_BidirectionalIterator __first, _BidirectionalIterator __middle, _BidirectionalIterator __last,
45433e519524SHoward Hinnant              _Compare __comp)
45443e519524SHoward Hinnant{
45453e519524SHoward Hinnant    typedef typename iterator_traits<_BidirectionalIterator>::value_type value_type;
45463e519524SHoward Hinnant    typedef typename iterator_traits<_BidirectionalIterator>::difference_type difference_type;
4547ce48a113SHoward Hinnant    difference_type __len1 = _VSTD::distance(__first, __middle);
4548ce48a113SHoward Hinnant    difference_type __len2 = _VSTD::distance(__middle, __last);
4549ce48a113SHoward Hinnant    difference_type __buf_size = _VSTD::min(__len1, __len2);
45500b48cf9aSMarshall Clow    pair<value_type*, ptrdiff_t> __buf = _VSTD::get_temporary_buffer<value_type>(__buf_size);
45510b48cf9aSMarshall Clow    unique_ptr<value_type, __return_temporary_buffer> __h(__buf.first);
45520b48cf9aSMarshall Clow
4553145afa17SHoward Hinnant#ifdef _LIBCPP_DEBUG
45543e519524SHoward Hinnant    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
45553e519524SHoward Hinnant    __debug_less<_Compare> __c(__comp);
4556ce48a113SHoward Hinnant    return _VSTD::__inplace_merge<_Comp_ref>(__first, __middle, __last, __c, __len1, __len2,
45573e519524SHoward Hinnant                                            __buf.first, __buf.second);
4558145afa17SHoward Hinnant#else  // _LIBCPP_DEBUG
45593e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
4560ce48a113SHoward Hinnant    return _VSTD::__inplace_merge<_Comp_ref>(__first, __middle, __last, __comp, __len1, __len2,
45613e519524SHoward Hinnant                                            __buf.first, __buf.second);
4562145afa17SHoward Hinnant#endif  // _LIBCPP_DEBUG
45633e519524SHoward Hinnant}
45643e519524SHoward Hinnant
45653e519524SHoward Hinnanttemplate <class _BidirectionalIterator>
45663e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
45673e519524SHoward Hinnantvoid
45683e519524SHoward Hinnantinplace_merge(_BidirectionalIterator __first, _BidirectionalIterator __middle, _BidirectionalIterator __last)
45693e519524SHoward Hinnant{
4570ce48a113SHoward Hinnant    _VSTD::inplace_merge(__first, __middle, __last,
45713e519524SHoward Hinnant                        __less<typename iterator_traits<_BidirectionalIterator>::value_type>());
45723e519524SHoward Hinnant}
45733e519524SHoward Hinnant
45743e519524SHoward Hinnant// stable_sort
45753e519524SHoward Hinnant
45763e519524SHoward Hinnanttemplate <class _Compare, class _InputIterator1, class _InputIterator2>
45773e519524SHoward Hinnantvoid
45783e519524SHoward Hinnant__merge_move_construct(_InputIterator1 __first1, _InputIterator1 __last1,
45793e519524SHoward Hinnant        _InputIterator2 __first2, _InputIterator2 __last2,
45803e519524SHoward Hinnant        typename iterator_traits<_InputIterator1>::value_type* __result, _Compare __comp)
45813e519524SHoward Hinnant{
45823e519524SHoward Hinnant    typedef typename iterator_traits<_InputIterator1>::value_type value_type;
45833e519524SHoward Hinnant    __destruct_n __d(0);
45843e519524SHoward Hinnant    unique_ptr<value_type, __destruct_n&> __h(__result, __d);
45853e519524SHoward Hinnant    for (; true; ++__result)
45863e519524SHoward Hinnant    {
45873e519524SHoward Hinnant        if (__first1 == __last1)
45883e519524SHoward Hinnant        {
45893e519524SHoward Hinnant            for (; __first2 != __last2; ++__first2, ++__result, __d.__incr((value_type*)0))
4590ce48a113SHoward Hinnant                ::new (__result) value_type(_VSTD::move(*__first2));
45913e519524SHoward Hinnant            __h.release();
45923e519524SHoward Hinnant            return;
45933e519524SHoward Hinnant        }
45943e519524SHoward Hinnant        if (__first2 == __last2)
45953e519524SHoward Hinnant        {
45963e519524SHoward Hinnant            for (; __first1 != __last1; ++__first1, ++__result, __d.__incr((value_type*)0))
4597ce48a113SHoward Hinnant                ::new (__result) value_type(_VSTD::move(*__first1));
45983e519524SHoward Hinnant            __h.release();
45993e519524SHoward Hinnant            return;
46003e519524SHoward Hinnant        }
46013e519524SHoward Hinnant        if (__comp(*__first2, *__first1))
46023e519524SHoward Hinnant        {
4603ce48a113SHoward Hinnant            ::new (__result) value_type(_VSTD::move(*__first2));
46043e519524SHoward Hinnant            __d.__incr((value_type*)0);
46053e519524SHoward Hinnant            ++__first2;
46063e519524SHoward Hinnant        }
46073e519524SHoward Hinnant        else
46083e519524SHoward Hinnant        {
4609ce48a113SHoward Hinnant            ::new (__result) value_type(_VSTD::move(*__first1));
46103e519524SHoward Hinnant            __d.__incr((value_type*)0);
46113e519524SHoward Hinnant            ++__first1;
46123e519524SHoward Hinnant        }
46133e519524SHoward Hinnant    }
46143e519524SHoward Hinnant}
46153e519524SHoward Hinnant
46163e519524SHoward Hinnanttemplate <class _Compare, class _InputIterator1, class _InputIterator2, class _OutputIterator>
46173e519524SHoward Hinnantvoid
46183e519524SHoward Hinnant__merge_move_assign(_InputIterator1 __first1, _InputIterator1 __last1,
46193e519524SHoward Hinnant        _InputIterator2 __first2, _InputIterator2 __last2,
46203e519524SHoward Hinnant        _OutputIterator __result, _Compare __comp)
46213e519524SHoward Hinnant{
46223e519524SHoward Hinnant    for (; __first1 != __last1; ++__result)
46233e519524SHoward Hinnant    {
46243e519524SHoward Hinnant        if (__first2 == __last2)
46253e519524SHoward Hinnant        {
46263e519524SHoward Hinnant            for (; __first1 != __last1; ++__first1, ++__result)
4627ce48a113SHoward Hinnant                *__result = _VSTD::move(*__first1);
46283e519524SHoward Hinnant            return;
46293e519524SHoward Hinnant        }
46303e519524SHoward Hinnant        if (__comp(*__first2, *__first1))
46313e519524SHoward Hinnant        {
4632ce48a113SHoward Hinnant            *__result = _VSTD::move(*__first2);
46333e519524SHoward Hinnant            ++__first2;
46343e519524SHoward Hinnant        }
46353e519524SHoward Hinnant        else
46363e519524SHoward Hinnant        {
4637ce48a113SHoward Hinnant            *__result = _VSTD::move(*__first1);
46383e519524SHoward Hinnant            ++__first1;
46393e519524SHoward Hinnant        }
46403e519524SHoward Hinnant    }
46413e519524SHoward Hinnant    for (; __first2 != __last2; ++__first2, ++__result)
4642ce48a113SHoward Hinnant        *__result = _VSTD::move(*__first2);
46433e519524SHoward Hinnant}
46443e519524SHoward Hinnant
46453e519524SHoward Hinnanttemplate <class _Compare, class _RandomAccessIterator>
46463e519524SHoward Hinnantvoid
46473e519524SHoward Hinnant__stable_sort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp,
46483e519524SHoward Hinnant              typename iterator_traits<_RandomAccessIterator>::difference_type __len,
46493e519524SHoward Hinnant              typename iterator_traits<_RandomAccessIterator>::value_type* __buff, ptrdiff_t __buff_size);
46503e519524SHoward Hinnant
46513e519524SHoward Hinnanttemplate <class _Compare, class _RandomAccessIterator>
46523e519524SHoward Hinnantvoid
46533e519524SHoward Hinnant__stable_sort_move(_RandomAccessIterator __first1, _RandomAccessIterator __last1, _Compare __comp,
46543e519524SHoward Hinnant                   typename iterator_traits<_RandomAccessIterator>::difference_type __len,
46553e519524SHoward Hinnant                   typename iterator_traits<_RandomAccessIterator>::value_type* __first2)
46563e519524SHoward Hinnant{
46573e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
46583e519524SHoward Hinnant    switch (__len)
46593e519524SHoward Hinnant    {
46603e519524SHoward Hinnant    case 0:
46613e519524SHoward Hinnant        return;
46623e519524SHoward Hinnant    case 1:
4663ce48a113SHoward Hinnant        ::new(__first2) value_type(_VSTD::move(*__first1));
46643e519524SHoward Hinnant        return;
46653e519524SHoward Hinnant    case 2:
46663e519524SHoward Hinnant        __destruct_n __d(0);
46673e519524SHoward Hinnant        unique_ptr<value_type, __destruct_n&> __h2(__first2, __d);
46683e519524SHoward Hinnant        if (__comp(*--__last1, *__first1))
46693e519524SHoward Hinnant        {
4670ce48a113SHoward Hinnant            ::new(__first2) value_type(_VSTD::move(*__last1));
46713e519524SHoward Hinnant            __d.__incr((value_type*)0);
46723e519524SHoward Hinnant            ++__first2;
4673ce48a113SHoward Hinnant            ::new(__first2) value_type(_VSTD::move(*__first1));
46743e519524SHoward Hinnant        }
46753e519524SHoward Hinnant        else
46763e519524SHoward Hinnant        {
4677ce48a113SHoward Hinnant            ::new(__first2) value_type(_VSTD::move(*__first1));
46783e519524SHoward Hinnant            __d.__incr((value_type*)0);
46793e519524SHoward Hinnant            ++__first2;
4680ce48a113SHoward Hinnant            ::new(__first2) value_type(_VSTD::move(*__last1));
46813e519524SHoward Hinnant        }
46823e519524SHoward Hinnant        __h2.release();
46833e519524SHoward Hinnant        return;
46843e519524SHoward Hinnant    }
46853e519524SHoward Hinnant    if (__len <= 8)
46863e519524SHoward Hinnant    {
46873e519524SHoward Hinnant        __insertion_sort_move<_Compare>(__first1, __last1, __first2, __comp);
46883e519524SHoward Hinnant        return;
46893e519524SHoward Hinnant    }
46903e519524SHoward Hinnant    typename iterator_traits<_RandomAccessIterator>::difference_type __l2 = __len / 2;
46913e519524SHoward Hinnant    _RandomAccessIterator __m = __first1 + __l2;
46923e519524SHoward Hinnant    __stable_sort<_Compare>(__first1, __m, __comp, __l2, __first2, __l2);
46933e519524SHoward Hinnant    __stable_sort<_Compare>(__m, __last1, __comp, __len - __l2, __first2 + __l2, __len - __l2);
46943e519524SHoward Hinnant    __merge_move_construct<_Compare>(__first1, __m, __m, __last1, __first2, __comp);
46953e519524SHoward Hinnant}
46963e519524SHoward Hinnant
46973e519524SHoward Hinnanttemplate <class _Tp>
46983e519524SHoward Hinnantstruct __stable_sort_switch
46993e519524SHoward Hinnant{
4700ca740483SHoward Hinnant    static const unsigned value = 128*is_trivially_copy_assignable<_Tp>::value;
47013e519524SHoward Hinnant};
47023e519524SHoward Hinnant
47033e519524SHoward Hinnanttemplate <class _Compare, class _RandomAccessIterator>
47043e519524SHoward Hinnantvoid
47053e519524SHoward Hinnant__stable_sort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp,
47063e519524SHoward Hinnant              typename iterator_traits<_RandomAccessIterator>::difference_type __len,
47073e519524SHoward Hinnant              typename iterator_traits<_RandomAccessIterator>::value_type* __buff, ptrdiff_t __buff_size)
47083e519524SHoward Hinnant{
47093e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
47103e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
47113e519524SHoward Hinnant    switch (__len)
47123e519524SHoward Hinnant    {
47133e519524SHoward Hinnant    case 0:
47143e519524SHoward Hinnant    case 1:
47153e519524SHoward Hinnant        return;
47163e519524SHoward Hinnant    case 2:
47173e519524SHoward Hinnant        if (__comp(*--__last, *__first))
47183e519524SHoward Hinnant            swap(*__first, *__last);
47193e519524SHoward Hinnant        return;
47203e519524SHoward Hinnant    }
47213e519524SHoward Hinnant    if (__len <= static_cast<difference_type>(__stable_sort_switch<value_type>::value))
47223e519524SHoward Hinnant    {
47233e519524SHoward Hinnant        __insertion_sort<_Compare>(__first, __last, __comp);
47243e519524SHoward Hinnant        return;
47253e519524SHoward Hinnant    }
47263e519524SHoward Hinnant    typename iterator_traits<_RandomAccessIterator>::difference_type __l2 = __len / 2;
47273e519524SHoward Hinnant    _RandomAccessIterator __m = __first + __l2;
47283e519524SHoward Hinnant    if (__len <= __buff_size)
47293e519524SHoward Hinnant    {
47303e519524SHoward Hinnant        __destruct_n __d(0);
47313e519524SHoward Hinnant        unique_ptr<value_type, __destruct_n&> __h2(__buff, __d);
47323e519524SHoward Hinnant        __stable_sort_move<_Compare>(__first, __m, __comp, __l2, __buff);
47333e519524SHoward Hinnant        __d.__set(__l2, (value_type*)0);
47343e519524SHoward Hinnant        __stable_sort_move<_Compare>(__m, __last, __comp, __len - __l2, __buff + __l2);
47353e519524SHoward Hinnant        __d.__set(__len, (value_type*)0);
47363e519524SHoward Hinnant        __merge_move_assign<_Compare>(__buff, __buff + __l2, __buff + __l2, __buff + __len, __first, __comp);
47373e519524SHoward Hinnant//         __merge<_Compare>(move_iterator<value_type*>(__buff),
47383e519524SHoward Hinnant//                           move_iterator<value_type*>(__buff + __l2),
47393e519524SHoward Hinnant//                           move_iterator<_RandomAccessIterator>(__buff + __l2),
47403e519524SHoward Hinnant//                           move_iterator<_RandomAccessIterator>(__buff + __len),
47413e519524SHoward Hinnant//                           __first, __comp);
47423e519524SHoward Hinnant        return;
47433e519524SHoward Hinnant    }
47443e519524SHoward Hinnant    __stable_sort<_Compare>(__first, __m, __comp, __l2, __buff, __buff_size);
47453e519524SHoward Hinnant    __stable_sort<_Compare>(__m, __last, __comp, __len - __l2, __buff, __buff_size);
47463e519524SHoward Hinnant    __inplace_merge<_Compare>(__first, __m, __last, __comp, __l2, __len - __l2, __buff, __buff_size);
47473e519524SHoward Hinnant}
47483e519524SHoward Hinnant
47493e519524SHoward Hinnanttemplate <class _RandomAccessIterator, class _Compare>
47503e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
47513e519524SHoward Hinnantvoid
47523e519524SHoward Hinnantstable_sort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
47533e519524SHoward Hinnant{
47543e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
47553e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
47563e519524SHoward Hinnant    difference_type __len = __last - __first;
47573e519524SHoward Hinnant    pair<value_type*, ptrdiff_t> __buf(0, 0);
47583e519524SHoward Hinnant    unique_ptr<value_type, __return_temporary_buffer> __h;
47593e519524SHoward Hinnant    if (__len > static_cast<difference_type>(__stable_sort_switch<value_type>::value))
47603e519524SHoward Hinnant    {
4761ce48a113SHoward Hinnant        __buf = _VSTD::get_temporary_buffer<value_type>(__len);
47623e519524SHoward Hinnant        __h.reset(__buf.first);
47633e519524SHoward Hinnant    }
4764145afa17SHoward Hinnant#ifdef _LIBCPP_DEBUG
47653e519524SHoward Hinnant    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
47663e519524SHoward Hinnant    __debug_less<_Compare> __c(__comp);
47673e519524SHoward Hinnant    __stable_sort<_Comp_ref>(__first, __last, __c, __len, __buf.first, __buf.second);
4768145afa17SHoward Hinnant#else  // _LIBCPP_DEBUG
47693e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
47703e519524SHoward Hinnant    __stable_sort<_Comp_ref>(__first, __last, __comp, __len, __buf.first, __buf.second);
4771145afa17SHoward Hinnant#endif  // _LIBCPP_DEBUG
47723e519524SHoward Hinnant}
47733e519524SHoward Hinnant
47743e519524SHoward Hinnanttemplate <class _RandomAccessIterator>
47753e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
47763e519524SHoward Hinnantvoid
47773e519524SHoward Hinnantstable_sort(_RandomAccessIterator __first, _RandomAccessIterator __last)
47783e519524SHoward Hinnant{
4779ce48a113SHoward Hinnant    _VSTD::stable_sort(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
47803e519524SHoward Hinnant}
47813e519524SHoward Hinnant
47823e519524SHoward Hinnant// is_heap_until
47833e519524SHoward Hinnant
47843e519524SHoward Hinnanttemplate <class _RandomAccessIterator, class _Compare>
4785*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT _LIBCPP_CONSTEXPR_AFTER_CXX17 _RandomAccessIterator
47863e519524SHoward Hinnantis_heap_until(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
47873e519524SHoward Hinnant{
4788ce48a113SHoward Hinnant    typedef typename _VSTD::iterator_traits<_RandomAccessIterator>::difference_type difference_type;
47893e519524SHoward Hinnant    difference_type __len = __last - __first;
47903e519524SHoward Hinnant    difference_type __p = 0;
47913e519524SHoward Hinnant    difference_type __c = 1;
47923e519524SHoward Hinnant    _RandomAccessIterator __pp = __first;
47933e519524SHoward Hinnant    while (__c < __len)
47943e519524SHoward Hinnant    {
47953e519524SHoward Hinnant        _RandomAccessIterator __cp = __first + __c;
47963e519524SHoward Hinnant        if (__comp(*__pp, *__cp))
47973e519524SHoward Hinnant            return __cp;
47983e519524SHoward Hinnant        ++__c;
47993e519524SHoward Hinnant        ++__cp;
48003e519524SHoward Hinnant        if (__c == __len)
48013e519524SHoward Hinnant            return __last;
48023e519524SHoward Hinnant        if (__comp(*__pp, *__cp))
48033e519524SHoward Hinnant            return __cp;
48043e519524SHoward Hinnant        ++__p;
48053e519524SHoward Hinnant        ++__pp;
48063e519524SHoward Hinnant        __c = 2 * __p + 1;
48073e519524SHoward Hinnant    }
48083e519524SHoward Hinnant    return __last;
48093e519524SHoward Hinnant}
48103e519524SHoward Hinnant
48113e519524SHoward Hinnanttemplate<class _RandomAccessIterator>
4812*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
4813*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
48143e519524SHoward Hinnant_RandomAccessIterator
48153e519524SHoward Hinnantis_heap_until(_RandomAccessIterator __first, _RandomAccessIterator __last)
48163e519524SHoward Hinnant{
4817ce48a113SHoward Hinnant    return _VSTD::is_heap_until(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
48183e519524SHoward Hinnant}
48193e519524SHoward Hinnant
48203e519524SHoward Hinnant// is_heap
48213e519524SHoward Hinnant
48223e519524SHoward Hinnanttemplate <class _RandomAccessIterator, class _Compare>
4823*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
4824*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
48253e519524SHoward Hinnantbool
48263e519524SHoward Hinnantis_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
48273e519524SHoward Hinnant{
4828ce48a113SHoward Hinnant    return _VSTD::is_heap_until(__first, __last, __comp) == __last;
48293e519524SHoward Hinnant}
48303e519524SHoward Hinnant
48313e519524SHoward Hinnanttemplate<class _RandomAccessIterator>
4832*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
4833*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
48343e519524SHoward Hinnantbool
48353e519524SHoward Hinnantis_heap(_RandomAccessIterator __first, _RandomAccessIterator __last)
48363e519524SHoward Hinnant{
4837ce48a113SHoward Hinnant    return _VSTD::is_heap(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
48383e519524SHoward Hinnant}
48393e519524SHoward Hinnant
48403e519524SHoward Hinnant// push_heap
48413e519524SHoward Hinnant
48423e519524SHoward Hinnanttemplate <class _Compare, class _RandomAccessIterator>
48433e519524SHoward Hinnantvoid
48448b512602SDavid Majnemer__sift_up(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp,
48453e519524SHoward Hinnant          typename iterator_traits<_RandomAccessIterator>::difference_type __len)
48463e519524SHoward Hinnant{
48473e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
48483e519524SHoward Hinnant    if (__len > 1)
48493e519524SHoward Hinnant    {
48503e519524SHoward Hinnant        __len = (__len - 2) / 2;
48513e519524SHoward Hinnant        _RandomAccessIterator __ptr = __first + __len;
48523e519524SHoward Hinnant        if (__comp(*__ptr, *--__last))
48533e519524SHoward Hinnant        {
4854ce48a113SHoward Hinnant            value_type __t(_VSTD::move(*__last));
48553e519524SHoward Hinnant            do
48563e519524SHoward Hinnant            {
4857ce48a113SHoward Hinnant                *__last = _VSTD::move(*__ptr);
48583e519524SHoward Hinnant                __last = __ptr;
48593e519524SHoward Hinnant                if (__len == 0)
48603e519524SHoward Hinnant                    break;
48613e519524SHoward Hinnant                __len = (__len - 1) / 2;
48623e519524SHoward Hinnant                __ptr = __first + __len;
48633e519524SHoward Hinnant            } while (__comp(*__ptr, __t));
4864ce48a113SHoward Hinnant            *__last = _VSTD::move(__t);
48653e519524SHoward Hinnant        }
48663e519524SHoward Hinnant    }
48673e519524SHoward Hinnant}
48683e519524SHoward Hinnant
48693e519524SHoward Hinnanttemplate <class _RandomAccessIterator, class _Compare>
48703e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
48713e519524SHoward Hinnantvoid
48723e519524SHoward Hinnantpush_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
48733e519524SHoward Hinnant{
4874145afa17SHoward Hinnant#ifdef _LIBCPP_DEBUG
48753e519524SHoward Hinnant    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
48763e519524SHoward Hinnant    __debug_less<_Compare> __c(__comp);
48778b512602SDavid Majnemer    __sift_up<_Comp_ref>(__first, __last, __c, __last - __first);
4878145afa17SHoward Hinnant#else  // _LIBCPP_DEBUG
48793e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
48808b512602SDavid Majnemer    __sift_up<_Comp_ref>(__first, __last, __comp, __last - __first);
4881145afa17SHoward Hinnant#endif  // _LIBCPP_DEBUG
48823e519524SHoward Hinnant}
48833e519524SHoward Hinnant
48843e519524SHoward Hinnanttemplate <class _RandomAccessIterator>
48853e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
48863e519524SHoward Hinnantvoid
48873e519524SHoward Hinnantpush_heap(_RandomAccessIterator __first, _RandomAccessIterator __last)
48883e519524SHoward Hinnant{
4889ce48a113SHoward Hinnant    _VSTD::push_heap(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
48903e519524SHoward Hinnant}
48913e519524SHoward Hinnant
48923e519524SHoward Hinnant// pop_heap
48933e519524SHoward Hinnant
48943e519524SHoward Hinnanttemplate <class _Compare, class _RandomAccessIterator>
48958b512602SDavid Majnemervoid
4896fd838227SEric Fiselier__sift_down(_RandomAccessIterator __first, _RandomAccessIterator /*__last*/,
4897fd838227SEric Fiselier            _Compare __comp,
48988b512602SDavid Majnemer            typename iterator_traits<_RandomAccessIterator>::difference_type __len,
48998b512602SDavid Majnemer            _RandomAccessIterator __start)
49008b512602SDavid Majnemer{
49018b512602SDavid Majnemer    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
49028b512602SDavid Majnemer    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
49038b512602SDavid Majnemer    // left-child of __start is at 2 * __start + 1
49048b512602SDavid Majnemer    // right-child of __start is at 2 * __start + 2
49058b512602SDavid Majnemer    difference_type __child = __start - __first;
49068b512602SDavid Majnemer
49078b512602SDavid Majnemer    if (__len < 2 || (__len - 2) / 2 < __child)
49088b512602SDavid Majnemer        return;
49098b512602SDavid Majnemer
49108b512602SDavid Majnemer    __child = 2 * __child + 1;
49118b512602SDavid Majnemer    _RandomAccessIterator __child_i = __first + __child;
49128b512602SDavid Majnemer
49138b512602SDavid Majnemer    if ((__child + 1) < __len && __comp(*__child_i, *(__child_i + 1))) {
49148b512602SDavid Majnemer        // right-child exists and is greater than left-child
49158b512602SDavid Majnemer        ++__child_i;
49168b512602SDavid Majnemer        ++__child;
49178b512602SDavid Majnemer    }
49188b512602SDavid Majnemer
49198b512602SDavid Majnemer    // check if we are in heap-order
49208b512602SDavid Majnemer    if (__comp(*__child_i, *__start))
49218b512602SDavid Majnemer        // we are, __start is larger than it's largest child
49228b512602SDavid Majnemer        return;
49238b512602SDavid Majnemer
49248b512602SDavid Majnemer    value_type __top(_VSTD::move(*__start));
49258b512602SDavid Majnemer    do
49268b512602SDavid Majnemer    {
49278b512602SDavid Majnemer        // we are not in heap-order, swap the parent with it's largest child
49288b512602SDavid Majnemer        *__start = _VSTD::move(*__child_i);
49298b512602SDavid Majnemer        __start = __child_i;
49308b512602SDavid Majnemer
49318b512602SDavid Majnemer        if ((__len - 2) / 2 < __child)
49328b512602SDavid Majnemer            break;
49338b512602SDavid Majnemer
49348b512602SDavid Majnemer        // recompute the child based off of the updated parent
49358b512602SDavid Majnemer        __child = 2 * __child + 1;
49368b512602SDavid Majnemer        __child_i = __first + __child;
49378b512602SDavid Majnemer
49388b512602SDavid Majnemer        if ((__child + 1) < __len && __comp(*__child_i, *(__child_i + 1))) {
49398b512602SDavid Majnemer            // right-child exists and is greater than left-child
49408b512602SDavid Majnemer            ++__child_i;
49418b512602SDavid Majnemer            ++__child;
49428b512602SDavid Majnemer        }
49438b512602SDavid Majnemer
49448b512602SDavid Majnemer        // check if we are in heap-order
49458b512602SDavid Majnemer    } while (!__comp(*__child_i, __top));
49468b512602SDavid Majnemer    *__start = _VSTD::move(__top);
49478b512602SDavid Majnemer}
49488b512602SDavid Majnemer
49498b512602SDavid Majnemertemplate <class _Compare, class _RandomAccessIterator>
49503e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
49513e519524SHoward Hinnantvoid
49523e519524SHoward Hinnant__pop_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp,
49533e519524SHoward Hinnant           typename iterator_traits<_RandomAccessIterator>::difference_type __len)
49543e519524SHoward Hinnant{
49553e519524SHoward Hinnant    if (__len > 1)
49563e519524SHoward Hinnant    {
49573e519524SHoward Hinnant        swap(*__first, *--__last);
49588b512602SDavid Majnemer        __sift_down<_Compare>(__first, __last, __comp, __len - 1, __first);
49593e519524SHoward Hinnant    }
49603e519524SHoward Hinnant}
49613e519524SHoward Hinnant
49623e519524SHoward Hinnanttemplate <class _RandomAccessIterator, class _Compare>
49633e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
49643e519524SHoward Hinnantvoid
49653e519524SHoward Hinnantpop_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
49663e519524SHoward Hinnant{
4967145afa17SHoward Hinnant#ifdef _LIBCPP_DEBUG
49683e519524SHoward Hinnant    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
49693e519524SHoward Hinnant    __debug_less<_Compare> __c(__comp);
49703e519524SHoward Hinnant    __pop_heap<_Comp_ref>(__first, __last, __c, __last - __first);
4971145afa17SHoward Hinnant#else  // _LIBCPP_DEBUG
49723e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
49733e519524SHoward Hinnant    __pop_heap<_Comp_ref>(__first, __last, __comp, __last - __first);
4974145afa17SHoward Hinnant#endif  // _LIBCPP_DEBUG
49753e519524SHoward Hinnant}
49763e519524SHoward Hinnant
49773e519524SHoward Hinnanttemplate <class _RandomAccessIterator>
49783e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
49793e519524SHoward Hinnantvoid
49803e519524SHoward Hinnantpop_heap(_RandomAccessIterator __first, _RandomAccessIterator __last)
49813e519524SHoward Hinnant{
4982ce48a113SHoward Hinnant    _VSTD::pop_heap(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
49833e519524SHoward Hinnant}
49843e519524SHoward Hinnant
49853e519524SHoward Hinnant// make_heap
49863e519524SHoward Hinnant
49873e519524SHoward Hinnanttemplate <class _Compare, class _RandomAccessIterator>
49883e519524SHoward Hinnantvoid
49893e519524SHoward Hinnant__make_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
49903e519524SHoward Hinnant{
49913e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
49923e519524SHoward Hinnant    difference_type __n = __last - __first;
49933e519524SHoward Hinnant    if (__n > 1)
49943e519524SHoward Hinnant    {
49958b512602SDavid Majnemer        // start from the first parent, there is no need to consider children
49968b512602SDavid Majnemer        for (difference_type __start = (__n - 2) / 2; __start >= 0; --__start)
49978b512602SDavid Majnemer        {
49988b512602SDavid Majnemer            __sift_down<_Compare>(__first, __last, __comp, __n, __first + __start);
49998b512602SDavid Majnemer        }
50003e519524SHoward Hinnant    }
50013e519524SHoward Hinnant}
50023e519524SHoward Hinnant
50033e519524SHoward Hinnanttemplate <class _RandomAccessIterator, class _Compare>
50043e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
50053e519524SHoward Hinnantvoid
50063e519524SHoward Hinnantmake_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
50073e519524SHoward Hinnant{
5008145afa17SHoward Hinnant#ifdef _LIBCPP_DEBUG
50093e519524SHoward Hinnant    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
50103e519524SHoward Hinnant    __debug_less<_Compare> __c(__comp);
50113e519524SHoward Hinnant    __make_heap<_Comp_ref>(__first, __last, __c);
5012145afa17SHoward Hinnant#else  // _LIBCPP_DEBUG
50133e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
50143e519524SHoward Hinnant    __make_heap<_Comp_ref>(__first, __last, __comp);
5015145afa17SHoward Hinnant#endif  // _LIBCPP_DEBUG
50163e519524SHoward Hinnant}
50173e519524SHoward Hinnant
50183e519524SHoward Hinnanttemplate <class _RandomAccessIterator>
50193e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
50203e519524SHoward Hinnantvoid
50213e519524SHoward Hinnantmake_heap(_RandomAccessIterator __first, _RandomAccessIterator __last)
50223e519524SHoward Hinnant{
5023ce48a113SHoward Hinnant    _VSTD::make_heap(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
50243e519524SHoward Hinnant}
50253e519524SHoward Hinnant
50263e519524SHoward Hinnant// sort_heap
50273e519524SHoward Hinnant
50283e519524SHoward Hinnanttemplate <class _Compare, class _RandomAccessIterator>
50293e519524SHoward Hinnantvoid
50303e519524SHoward Hinnant__sort_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
50313e519524SHoward Hinnant{
50323e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
50333e519524SHoward Hinnant    for (difference_type __n = __last - __first; __n > 1; --__last, --__n)
50343e519524SHoward Hinnant        __pop_heap<_Compare>(__first, __last, __comp, __n);
50353e519524SHoward Hinnant}
50363e519524SHoward Hinnant
50373e519524SHoward Hinnanttemplate <class _RandomAccessIterator, class _Compare>
50383e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
50393e519524SHoward Hinnantvoid
50403e519524SHoward Hinnantsort_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
50413e519524SHoward Hinnant{
5042145afa17SHoward Hinnant#ifdef _LIBCPP_DEBUG
50433e519524SHoward Hinnant    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
50443e519524SHoward Hinnant    __debug_less<_Compare> __c(__comp);
50453e519524SHoward Hinnant    __sort_heap<_Comp_ref>(__first, __last, __c);
5046145afa17SHoward Hinnant#else  // _LIBCPP_DEBUG
50473e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
50483e519524SHoward Hinnant    __sort_heap<_Comp_ref>(__first, __last, __comp);
5049145afa17SHoward Hinnant#endif  // _LIBCPP_DEBUG
50503e519524SHoward Hinnant}
50513e519524SHoward Hinnant
50523e519524SHoward Hinnanttemplate <class _RandomAccessIterator>
50533e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
50543e519524SHoward Hinnantvoid
50553e519524SHoward Hinnantsort_heap(_RandomAccessIterator __first, _RandomAccessIterator __last)
50563e519524SHoward Hinnant{
5057ce48a113SHoward Hinnant    _VSTD::sort_heap(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
50583e519524SHoward Hinnant}
50593e519524SHoward Hinnant
50603e519524SHoward Hinnant// partial_sort
50613e519524SHoward Hinnant
50623e519524SHoward Hinnanttemplate <class _Compare, class _RandomAccessIterator>
50633e519524SHoward Hinnantvoid
50643e519524SHoward Hinnant__partial_sort(_RandomAccessIterator __first, _RandomAccessIterator __middle, _RandomAccessIterator __last,
50653e519524SHoward Hinnant             _Compare __comp)
50663e519524SHoward Hinnant{
50673e519524SHoward Hinnant    __make_heap<_Compare>(__first, __middle, __comp);
50683e519524SHoward Hinnant    typename iterator_traits<_RandomAccessIterator>::difference_type __len = __middle - __first;
50693e519524SHoward Hinnant    for (_RandomAccessIterator __i = __middle; __i != __last; ++__i)
50703e519524SHoward Hinnant    {
50713e519524SHoward Hinnant        if (__comp(*__i, *__first))
50723e519524SHoward Hinnant        {
50733e519524SHoward Hinnant            swap(*__i, *__first);
50748b512602SDavid Majnemer            __sift_down<_Compare>(__first, __middle, __comp, __len, __first);
50753e519524SHoward Hinnant        }
50763e519524SHoward Hinnant    }
50773e519524SHoward Hinnant    __sort_heap<_Compare>(__first, __middle, __comp);
50783e519524SHoward Hinnant}
50793e519524SHoward Hinnant
50803e519524SHoward Hinnanttemplate <class _RandomAccessIterator, class _Compare>
50813e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
50823e519524SHoward Hinnantvoid
50833e519524SHoward Hinnantpartial_sort(_RandomAccessIterator __first, _RandomAccessIterator __middle, _RandomAccessIterator __last,
50843e519524SHoward Hinnant             _Compare __comp)
50853e519524SHoward Hinnant{
5086145afa17SHoward Hinnant#ifdef _LIBCPP_DEBUG
50873e519524SHoward Hinnant    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
50883e519524SHoward Hinnant    __debug_less<_Compare> __c(__comp);
50893e519524SHoward Hinnant    __partial_sort<_Comp_ref>(__first, __middle, __last, __c);
5090145afa17SHoward Hinnant#else  // _LIBCPP_DEBUG
50913e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
50923e519524SHoward Hinnant    __partial_sort<_Comp_ref>(__first, __middle, __last, __comp);
5093145afa17SHoward Hinnant#endif  // _LIBCPP_DEBUG
50943e519524SHoward Hinnant}
50953e519524SHoward Hinnant
50963e519524SHoward Hinnanttemplate <class _RandomAccessIterator>
50973e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
50983e519524SHoward Hinnantvoid
50993e519524SHoward Hinnantpartial_sort(_RandomAccessIterator __first, _RandomAccessIterator __middle, _RandomAccessIterator __last)
51003e519524SHoward Hinnant{
5101ce48a113SHoward Hinnant    _VSTD::partial_sort(__first, __middle, __last,
51023e519524SHoward Hinnant                       __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
51033e519524SHoward Hinnant}
51043e519524SHoward Hinnant
51053e519524SHoward Hinnant// partial_sort_copy
51063e519524SHoward Hinnant
51073e519524SHoward Hinnanttemplate <class _Compare, class _InputIterator, class _RandomAccessIterator>
51083e519524SHoward Hinnant_RandomAccessIterator
51093e519524SHoward Hinnant__partial_sort_copy(_InputIterator __first, _InputIterator __last,
51103e519524SHoward Hinnant                    _RandomAccessIterator __result_first, _RandomAccessIterator __result_last, _Compare __comp)
51113e519524SHoward Hinnant{
51123e519524SHoward Hinnant    _RandomAccessIterator __r = __result_first;
51133e519524SHoward Hinnant    if (__r != __result_last)
51143e519524SHoward Hinnant    {
5115910285b2SEric Fiselier        for (; __first != __last && __r != __result_last; (void) ++__first, ++__r)
51163e519524SHoward Hinnant            *__r = *__first;
51173e519524SHoward Hinnant        __make_heap<_Compare>(__result_first, __r, __comp);
51188b512602SDavid Majnemer        typename iterator_traits<_RandomAccessIterator>::difference_type __len = __r - __result_first;
51193e519524SHoward Hinnant        for (; __first != __last; ++__first)
51203e519524SHoward Hinnant            if (__comp(*__first, *__result_first))
51213e519524SHoward Hinnant            {
51223e519524SHoward Hinnant                *__result_first = *__first;
51238b512602SDavid Majnemer                __sift_down<_Compare>(__result_first, __r, __comp, __len, __result_first);
51243e519524SHoward Hinnant            }
51253e519524SHoward Hinnant        __sort_heap<_Compare>(__result_first, __r, __comp);
51263e519524SHoward Hinnant    }
51273e519524SHoward Hinnant    return __r;
51283e519524SHoward Hinnant}
51293e519524SHoward Hinnant
51303e519524SHoward Hinnanttemplate <class _InputIterator, class _RandomAccessIterator, class _Compare>
51313e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
51323e519524SHoward Hinnant_RandomAccessIterator
51333e519524SHoward Hinnantpartial_sort_copy(_InputIterator __first, _InputIterator __last,
51343e519524SHoward Hinnant                  _RandomAccessIterator __result_first, _RandomAccessIterator __result_last, _Compare __comp)
51353e519524SHoward Hinnant{
5136145afa17SHoward Hinnant#ifdef _LIBCPP_DEBUG
51373e519524SHoward Hinnant    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
51383e519524SHoward Hinnant    __debug_less<_Compare> __c(__comp);
51393e519524SHoward Hinnant    return __partial_sort_copy<_Comp_ref>(__first, __last, __result_first, __result_last, __c);
5140145afa17SHoward Hinnant#else  // _LIBCPP_DEBUG
51413e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
51423e519524SHoward Hinnant    return __partial_sort_copy<_Comp_ref>(__first, __last, __result_first, __result_last, __comp);
5143145afa17SHoward Hinnant#endif  // _LIBCPP_DEBUG
51443e519524SHoward Hinnant}
51453e519524SHoward Hinnant
51463e519524SHoward Hinnanttemplate <class _InputIterator, class _RandomAccessIterator>
51473e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
51483e519524SHoward Hinnant_RandomAccessIterator
51493e519524SHoward Hinnantpartial_sort_copy(_InputIterator __first, _InputIterator __last,
51503e519524SHoward Hinnant                  _RandomAccessIterator __result_first, _RandomAccessIterator __result_last)
51513e519524SHoward Hinnant{
5152ce48a113SHoward Hinnant    return _VSTD::partial_sort_copy(__first, __last, __result_first, __result_last,
51533e519524SHoward Hinnant                                   __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
51543e519524SHoward Hinnant}
51553e519524SHoward Hinnant
51563e519524SHoward Hinnant// nth_element
51573e519524SHoward Hinnant
51583e519524SHoward Hinnanttemplate <class _Compare, class _RandomAccessIterator>
51593e519524SHoward Hinnantvoid
51603e519524SHoward Hinnant__nth_element(_RandomAccessIterator __first, _RandomAccessIterator __nth, _RandomAccessIterator __last, _Compare __comp)
51613e519524SHoward Hinnant{
51623e519524SHoward Hinnant    // _Compare is known to be a reference type
51633e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
51643e519524SHoward Hinnant    const difference_type __limit = 7;
51653e519524SHoward Hinnant    while (true)
51663e519524SHoward Hinnant    {
51673e519524SHoward Hinnant    __restart:
5168b34b4819SHoward Hinnant        if (__nth == __last)
5169b34b4819SHoward Hinnant            return;
51703e519524SHoward Hinnant        difference_type __len = __last - __first;
51713e519524SHoward Hinnant        switch (__len)
51723e519524SHoward Hinnant        {
51733e519524SHoward Hinnant        case 0:
51743e519524SHoward Hinnant        case 1:
51753e519524SHoward Hinnant            return;
51763e519524SHoward Hinnant        case 2:
51773e519524SHoward Hinnant            if (__comp(*--__last, *__first))
51783e519524SHoward Hinnant                swap(*__first, *__last);
51793e519524SHoward Hinnant            return;
51803e519524SHoward Hinnant        case 3:
51813e519524SHoward Hinnant            {
51823e519524SHoward Hinnant            _RandomAccessIterator __m = __first;
5183ce48a113SHoward Hinnant            _VSTD::__sort3<_Compare>(__first, ++__m, --__last, __comp);
51843e519524SHoward Hinnant            return;
51853e519524SHoward Hinnant            }
51863e519524SHoward Hinnant        }
51873e519524SHoward Hinnant        if (__len <= __limit)
51883e519524SHoward Hinnant        {
51893e519524SHoward Hinnant            __selection_sort<_Compare>(__first, __last, __comp);
51903e519524SHoward Hinnant            return;
51913e519524SHoward Hinnant        }
51923e519524SHoward Hinnant        // __len > __limit >= 3
51933e519524SHoward Hinnant        _RandomAccessIterator __m = __first + __len/2;
51943e519524SHoward Hinnant        _RandomAccessIterator __lm1 = __last;
5195ce48a113SHoward Hinnant        unsigned __n_swaps = _VSTD::__sort3<_Compare>(__first, __m, --__lm1, __comp);
51963e519524SHoward Hinnant        // *__m is median
51973e519524SHoward Hinnant        // partition [__first, __m) < *__m and *__m <= [__m, __last)
51983e519524SHoward Hinnant        // (this inhibits tossing elements equivalent to __m around unnecessarily)
51993e519524SHoward Hinnant        _RandomAccessIterator __i = __first;
52003e519524SHoward Hinnant        _RandomAccessIterator __j = __lm1;
52013e519524SHoward Hinnant        // j points beyond range to be tested, *__lm1 is known to be <= *__m
52023e519524SHoward Hinnant        // The search going up is known to be guarded but the search coming down isn't.
52033e519524SHoward Hinnant        // Prime the downward search with a guard.
52043e519524SHoward Hinnant        if (!__comp(*__i, *__m))  // if *__first == *__m
52053e519524SHoward Hinnant        {
52063e519524SHoward Hinnant            // *__first == *__m, *__first doesn't go in first part
52073e519524SHoward Hinnant            // manually guard downward moving __j against __i
52083e519524SHoward Hinnant            while (true)
52093e519524SHoward Hinnant            {
52103e519524SHoward Hinnant                if (__i == --__j)
52113e519524SHoward Hinnant                {
52123e519524SHoward Hinnant                    // *__first == *__m, *__m <= all other elements
52133e519524SHoward Hinnant                    // Parition instead into [__first, __i) == *__first and *__first < [__i, __last)
52143e519524SHoward Hinnant                    ++__i;  // __first + 1
52153e519524SHoward Hinnant                    __j = __last;
52163e519524SHoward Hinnant                    if (!__comp(*__first, *--__j))  // we need a guard if *__first == *(__last-1)
52173e519524SHoward Hinnant                    {
52183e519524SHoward Hinnant                        while (true)
52193e519524SHoward Hinnant                        {
52203e519524SHoward Hinnant                            if (__i == __j)
52213e519524SHoward Hinnant                                return;  // [__first, __last) all equivalent elements
52223e519524SHoward Hinnant                            if (__comp(*__first, *__i))
52233e519524SHoward Hinnant                            {
52243e519524SHoward Hinnant                                swap(*__i, *__j);
52253e519524SHoward Hinnant                                ++__n_swaps;
52263e519524SHoward Hinnant                                ++__i;
52273e519524SHoward Hinnant                                break;
52283e519524SHoward Hinnant                            }
52293e519524SHoward Hinnant                            ++__i;
52303e519524SHoward Hinnant                        }
52313e519524SHoward Hinnant                    }
52323e519524SHoward Hinnant                    // [__first, __i) == *__first and *__first < [__j, __last) and __j == __last - 1
52333e519524SHoward Hinnant                    if (__i == __j)
52343e519524SHoward Hinnant                        return;
52353e519524SHoward Hinnant                    while (true)
52363e519524SHoward Hinnant                    {
52373e519524SHoward Hinnant                        while (!__comp(*__first, *__i))
52383e519524SHoward Hinnant                            ++__i;
52393e519524SHoward Hinnant                        while (__comp(*__first, *--__j))
52403e519524SHoward Hinnant                            ;
52413e519524SHoward Hinnant                        if (__i >= __j)
52423e519524SHoward Hinnant                            break;
52433e519524SHoward Hinnant                        swap(*__i, *__j);
52443e519524SHoward Hinnant                        ++__n_swaps;
52453e519524SHoward Hinnant                        ++__i;
52463e519524SHoward Hinnant                    }
52473e519524SHoward Hinnant                    // [__first, __i) == *__first and *__first < [__i, __last)
52483e519524SHoward Hinnant                    // The first part is sorted,
52493e519524SHoward Hinnant                    if (__nth < __i)
52503e519524SHoward Hinnant                        return;
52513e519524SHoward Hinnant                    // __nth_element the secod part
52523e519524SHoward Hinnant                    // __nth_element<_Compare>(__i, __nth, __last, __comp);
52533e519524SHoward Hinnant                    __first = __i;
52543e519524SHoward Hinnant                    goto __restart;
52553e519524SHoward Hinnant                }
52563e519524SHoward Hinnant                if (__comp(*__j, *__m))
52573e519524SHoward Hinnant                {
52583e519524SHoward Hinnant                    swap(*__i, *__j);
52593e519524SHoward Hinnant                    ++__n_swaps;
52603e519524SHoward Hinnant                    break;  // found guard for downward moving __j, now use unguarded partition
52613e519524SHoward Hinnant                }
52623e519524SHoward Hinnant            }
52633e519524SHoward Hinnant        }
52643e519524SHoward Hinnant        ++__i;
52653e519524SHoward Hinnant        // j points beyond range to be tested, *__lm1 is known to be <= *__m
52663e519524SHoward Hinnant        // if not yet partitioned...
52673e519524SHoward Hinnant        if (__i < __j)
52683e519524SHoward Hinnant        {
52693e519524SHoward Hinnant            // known that *(__i - 1) < *__m
52703e519524SHoward Hinnant            while (true)
52713e519524SHoward Hinnant            {
52723e519524SHoward Hinnant                // __m still guards upward moving __i
52733e519524SHoward Hinnant                while (__comp(*__i, *__m))
52743e519524SHoward Hinnant                    ++__i;
52753e519524SHoward Hinnant                // It is now known that a guard exists for downward moving __j
52763e519524SHoward Hinnant                while (!__comp(*--__j, *__m))
52773e519524SHoward Hinnant                    ;
52783e519524SHoward Hinnant                if (__i >= __j)
52793e519524SHoward Hinnant                    break;
52803e519524SHoward Hinnant                swap(*__i, *__j);
52813e519524SHoward Hinnant                ++__n_swaps;
52823e519524SHoward Hinnant                // It is known that __m != __j
52833e519524SHoward Hinnant                // If __m just moved, follow it
52843e519524SHoward Hinnant                if (__m == __i)
52853e519524SHoward Hinnant                    __m = __j;
52863e519524SHoward Hinnant                ++__i;
52873e519524SHoward Hinnant            }
52883e519524SHoward Hinnant        }
52893e519524SHoward Hinnant        // [__first, __i) < *__m and *__m <= [__i, __last)
52903e519524SHoward Hinnant        if (__i != __m && __comp(*__m, *__i))
52913e519524SHoward Hinnant        {
52923e519524SHoward Hinnant            swap(*__i, *__m);
52933e519524SHoward Hinnant            ++__n_swaps;
52943e519524SHoward Hinnant        }
52953e519524SHoward Hinnant        // [__first, __i) < *__i and *__i <= [__i+1, __last)
52963e519524SHoward Hinnant        if (__nth == __i)
52973e519524SHoward Hinnant            return;
52983e519524SHoward Hinnant        if (__n_swaps == 0)
52993e519524SHoward Hinnant        {
53003e519524SHoward Hinnant            // We were given a perfectly partitioned sequence.  Coincidence?
53013e519524SHoward Hinnant            if (__nth < __i)
53023e519524SHoward Hinnant            {
53033e519524SHoward Hinnant                // Check for [__first, __i) already sorted
53043e519524SHoward Hinnant                __j = __m = __first;
53053e519524SHoward Hinnant                while (++__j != __i)
53063e519524SHoward Hinnant                {
53073e519524SHoward Hinnant                    if (__comp(*__j, *__m))
53083e519524SHoward Hinnant                        // not yet sorted, so sort
53093e519524SHoward Hinnant                        goto not_sorted;
53103e519524SHoward Hinnant                    __m = __j;
53113e519524SHoward Hinnant                }
53123e519524SHoward Hinnant                // [__first, __i) sorted
53133e519524SHoward Hinnant                return;
53143e519524SHoward Hinnant            }
53153e519524SHoward Hinnant            else
53163e519524SHoward Hinnant            {
53173e519524SHoward Hinnant                // Check for [__i, __last) already sorted
53183e519524SHoward Hinnant                __j = __m = __i;
53193e519524SHoward Hinnant                while (++__j != __last)
53203e519524SHoward Hinnant                {
53213e519524SHoward Hinnant                    if (__comp(*__j, *__m))
53223e519524SHoward Hinnant                        // not yet sorted, so sort
53233e519524SHoward Hinnant                        goto not_sorted;
53243e519524SHoward Hinnant                    __m = __j;
53253e519524SHoward Hinnant                }
53263e519524SHoward Hinnant                // [__i, __last) sorted
53273e519524SHoward Hinnant                return;
53283e519524SHoward Hinnant            }
53293e519524SHoward Hinnant        }
53303e519524SHoward Hinnantnot_sorted:
53313e519524SHoward Hinnant        // __nth_element on range containing __nth
53323e519524SHoward Hinnant        if (__nth < __i)
53333e519524SHoward Hinnant        {
53343e519524SHoward Hinnant            // __nth_element<_Compare>(__first, __nth, __i, __comp);
53353e519524SHoward Hinnant            __last = __i;
53363e519524SHoward Hinnant        }
53373e519524SHoward Hinnant        else
53383e519524SHoward Hinnant        {
53393e519524SHoward Hinnant            // __nth_element<_Compare>(__i+1, __nth, __last, __comp);
53403e519524SHoward Hinnant            __first = ++__i;
53413e519524SHoward Hinnant        }
53423e519524SHoward Hinnant    }
53433e519524SHoward Hinnant}
53443e519524SHoward Hinnant
53453e519524SHoward Hinnanttemplate <class _RandomAccessIterator, class _Compare>
53463e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
53473e519524SHoward Hinnantvoid
53483e519524SHoward Hinnantnth_element(_RandomAccessIterator __first, _RandomAccessIterator __nth, _RandomAccessIterator __last, _Compare __comp)
53493e519524SHoward Hinnant{
5350145afa17SHoward Hinnant#ifdef _LIBCPP_DEBUG
53513e519524SHoward Hinnant    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
53523e519524SHoward Hinnant    __debug_less<_Compare> __c(__comp);
53533e519524SHoward Hinnant    __nth_element<_Comp_ref>(__first, __nth, __last, __c);
5354145afa17SHoward Hinnant#else  // _LIBCPP_DEBUG
53553e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
53563e519524SHoward Hinnant    __nth_element<_Comp_ref>(__first, __nth, __last, __comp);
5357145afa17SHoward Hinnant#endif  // _LIBCPP_DEBUG
53583e519524SHoward Hinnant}
53593e519524SHoward Hinnant
53603e519524SHoward Hinnanttemplate <class _RandomAccessIterator>
53613e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
53623e519524SHoward Hinnantvoid
53633e519524SHoward Hinnantnth_element(_RandomAccessIterator __first, _RandomAccessIterator __nth, _RandomAccessIterator __last)
53643e519524SHoward Hinnant{
5365ce48a113SHoward Hinnant    _VSTD::nth_element(__first, __nth, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
53663e519524SHoward Hinnant}
53673e519524SHoward Hinnant
53683e519524SHoward Hinnant// includes
53693e519524SHoward Hinnant
53703e519524SHoward Hinnanttemplate <class _Compare, class _InputIterator1, class _InputIterator2>
53718da1a487SMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
53723e519524SHoward Hinnant__includes(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2,
53733e519524SHoward Hinnant           _Compare __comp)
53743e519524SHoward Hinnant{
53753e519524SHoward Hinnant    for (; __first2 != __last2; ++__first1)
53763e519524SHoward Hinnant    {
53773e519524SHoward Hinnant        if (__first1 == __last1 || __comp(*__first2, *__first1))
53783e519524SHoward Hinnant            return false;
53793e519524SHoward Hinnant        if (!__comp(*__first1, *__first2))
53803e519524SHoward Hinnant            ++__first2;
53813e519524SHoward Hinnant    }
53823e519524SHoward Hinnant    return true;
53833e519524SHoward Hinnant}
53843e519524SHoward Hinnant
53853e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _Compare>
5386*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
5387*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
53883e519524SHoward Hinnantbool
53893e519524SHoward Hinnantincludes(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2,
53903e519524SHoward Hinnant         _Compare __comp)
53913e519524SHoward Hinnant{
5392145afa17SHoward Hinnant#ifdef _LIBCPP_DEBUG
53933e519524SHoward Hinnant    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
53943e519524SHoward Hinnant    __debug_less<_Compare> __c(__comp);
53953e519524SHoward Hinnant    return __includes<_Comp_ref>(__first1, __last1, __first2, __last2, __c);
5396145afa17SHoward Hinnant#else  // _LIBCPP_DEBUG
53973e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
53983e519524SHoward Hinnant    return __includes<_Comp_ref>(__first1, __last1, __first2, __last2, __comp);
5399145afa17SHoward Hinnant#endif  // _LIBCPP_DEBUG
54003e519524SHoward Hinnant}
54013e519524SHoward Hinnant
54023e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2>
5403*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
5404*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
54053e519524SHoward Hinnantbool
54063e519524SHoward Hinnantincludes(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2)
54073e519524SHoward Hinnant{
5408ce48a113SHoward Hinnant    return _VSTD::includes(__first1, __last1, __first2, __last2,
54093e519524SHoward Hinnant                          __less<typename iterator_traits<_InputIterator1>::value_type,
54103e519524SHoward Hinnant                                 typename iterator_traits<_InputIterator2>::value_type>());
54113e519524SHoward Hinnant}
54123e519524SHoward Hinnant
54133e519524SHoward Hinnant// set_union
54143e519524SHoward Hinnant
54153e519524SHoward Hinnanttemplate <class _Compare, class _InputIterator1, class _InputIterator2, class _OutputIterator>
54163e519524SHoward Hinnant_OutputIterator
54173e519524SHoward Hinnant__set_union(_InputIterator1 __first1, _InputIterator1 __last1,
54183e519524SHoward Hinnant            _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
54193e519524SHoward Hinnant{
54203e519524SHoward Hinnant    for (; __first1 != __last1; ++__result)
54213e519524SHoward Hinnant    {
54223e519524SHoward Hinnant        if (__first2 == __last2)
5423ce48a113SHoward Hinnant            return _VSTD::copy(__first1, __last1, __result);
54243e519524SHoward Hinnant        if (__comp(*__first2, *__first1))
54253e519524SHoward Hinnant        {
54263e519524SHoward Hinnant            *__result = *__first2;
54273e519524SHoward Hinnant            ++__first2;
54283e519524SHoward Hinnant        }
54293e519524SHoward Hinnant        else
54303e519524SHoward Hinnant        {
54313e519524SHoward Hinnant            if (!__comp(*__first1, *__first2))
54323e519524SHoward Hinnant                ++__first2;
543305da5b02SMarshall Clow            *__result = *__first1;
54343e519524SHoward Hinnant            ++__first1;
54353e519524SHoward Hinnant        }
54363e519524SHoward Hinnant    }
5437ce48a113SHoward Hinnant    return _VSTD::copy(__first2, __last2, __result);
54383e519524SHoward Hinnant}
54393e519524SHoward Hinnant
54403e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
54413e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
54423e519524SHoward Hinnant_OutputIterator
54433e519524SHoward Hinnantset_union(_InputIterator1 __first1, _InputIterator1 __last1,
54443e519524SHoward Hinnant          _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
54453e519524SHoward Hinnant{
5446145afa17SHoward Hinnant#ifdef _LIBCPP_DEBUG
54473e519524SHoward Hinnant    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
54483e519524SHoward Hinnant    __debug_less<_Compare> __c(__comp);
54493e519524SHoward Hinnant    return __set_union<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __c);
5450145afa17SHoward Hinnant#else  // _LIBCPP_DEBUG
54513e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
54523e519524SHoward Hinnant    return __set_union<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __comp);
5453145afa17SHoward Hinnant#endif  // _LIBCPP_DEBUG
54543e519524SHoward Hinnant}
54553e519524SHoward Hinnant
54563e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _OutputIterator>
54573e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
54583e519524SHoward Hinnant_OutputIterator
54593e519524SHoward Hinnantset_union(_InputIterator1 __first1, _InputIterator1 __last1,
54603e519524SHoward Hinnant          _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result)
54613e519524SHoward Hinnant{
5462ce48a113SHoward Hinnant    return _VSTD::set_union(__first1, __last1, __first2, __last2, __result,
54633e519524SHoward Hinnant                          __less<typename iterator_traits<_InputIterator1>::value_type,
54643e519524SHoward Hinnant                                 typename iterator_traits<_InputIterator2>::value_type>());
54653e519524SHoward Hinnant}
54663e519524SHoward Hinnant
54673e519524SHoward Hinnant// set_intersection
54683e519524SHoward Hinnant
54693e519524SHoward Hinnanttemplate <class _Compare, class _InputIterator1, class _InputIterator2, class _OutputIterator>
54708da1a487SMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 _OutputIterator
54713e519524SHoward Hinnant__set_intersection(_InputIterator1 __first1, _InputIterator1 __last1,
54723e519524SHoward Hinnant                   _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
54733e519524SHoward Hinnant{
54743e519524SHoward Hinnant    while (__first1 != __last1 && __first2 != __last2)
54753e519524SHoward Hinnant    {
54763e519524SHoward Hinnant        if (__comp(*__first1, *__first2))
54773e519524SHoward Hinnant            ++__first1;
54783e519524SHoward Hinnant        else
54793e519524SHoward Hinnant        {
54803e519524SHoward Hinnant            if (!__comp(*__first2, *__first1))
54813e519524SHoward Hinnant            {
54823e519524SHoward Hinnant                *__result = *__first1;
54833e519524SHoward Hinnant                ++__result;
54843e519524SHoward Hinnant                ++__first1;
54853e519524SHoward Hinnant            }
54863e519524SHoward Hinnant            ++__first2;
54873e519524SHoward Hinnant        }
54883e519524SHoward Hinnant    }
54893e519524SHoward Hinnant    return __result;
54903e519524SHoward Hinnant}
54913e519524SHoward Hinnant
54923e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
54938da1a487SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
54943e519524SHoward Hinnant_OutputIterator
54953e519524SHoward Hinnantset_intersection(_InputIterator1 __first1, _InputIterator1 __last1,
54963e519524SHoward Hinnant                 _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
54973e519524SHoward Hinnant{
5498145afa17SHoward Hinnant#ifdef _LIBCPP_DEBUG
54993e519524SHoward Hinnant    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
55003e519524SHoward Hinnant    __debug_less<_Compare> __c(__comp);
55013e519524SHoward Hinnant    return __set_intersection<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __c);
5502145afa17SHoward Hinnant#else  // _LIBCPP_DEBUG
55033e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
55043e519524SHoward Hinnant    return __set_intersection<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __comp);
5505145afa17SHoward Hinnant#endif  // _LIBCPP_DEBUG
55063e519524SHoward Hinnant}
55073e519524SHoward Hinnant
55083e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _OutputIterator>
55098da1a487SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
55103e519524SHoward Hinnant_OutputIterator
55113e519524SHoward Hinnantset_intersection(_InputIterator1 __first1, _InputIterator1 __last1,
55123e519524SHoward Hinnant                 _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result)
55133e519524SHoward Hinnant{
5514ce48a113SHoward Hinnant    return _VSTD::set_intersection(__first1, __last1, __first2, __last2, __result,
55153e519524SHoward Hinnant                                  __less<typename iterator_traits<_InputIterator1>::value_type,
55163e519524SHoward Hinnant                                         typename iterator_traits<_InputIterator2>::value_type>());
55173e519524SHoward Hinnant}
55183e519524SHoward Hinnant
55193e519524SHoward Hinnant// set_difference
55203e519524SHoward Hinnant
55213e519524SHoward Hinnanttemplate <class _Compare, class _InputIterator1, class _InputIterator2, class _OutputIterator>
55223e519524SHoward Hinnant_OutputIterator
55233e519524SHoward Hinnant__set_difference(_InputIterator1 __first1, _InputIterator1 __last1,
55243e519524SHoward Hinnant                 _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
55253e519524SHoward Hinnant{
55263e519524SHoward Hinnant    while (__first1 != __last1)
55273e519524SHoward Hinnant    {
55283e519524SHoward Hinnant        if (__first2 == __last2)
5529ce48a113SHoward Hinnant            return _VSTD::copy(__first1, __last1, __result);
55303e519524SHoward Hinnant        if (__comp(*__first1, *__first2))
55313e519524SHoward Hinnant        {
55323e519524SHoward Hinnant            *__result = *__first1;
55333e519524SHoward Hinnant            ++__result;
55343e519524SHoward Hinnant            ++__first1;
55353e519524SHoward Hinnant        }
55363e519524SHoward Hinnant        else
55373e519524SHoward Hinnant        {
55383e519524SHoward Hinnant            if (!__comp(*__first2, *__first1))
55393e519524SHoward Hinnant                ++__first1;
55403e519524SHoward Hinnant            ++__first2;
55413e519524SHoward Hinnant        }
55423e519524SHoward Hinnant    }
55433e519524SHoward Hinnant    return __result;
55443e519524SHoward Hinnant}
55453e519524SHoward Hinnant
55463e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
55473e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
55483e519524SHoward Hinnant_OutputIterator
55493e519524SHoward Hinnantset_difference(_InputIterator1 __first1, _InputIterator1 __last1,
55503e519524SHoward Hinnant               _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
55513e519524SHoward Hinnant{
5552145afa17SHoward Hinnant#ifdef _LIBCPP_DEBUG
55533e519524SHoward Hinnant    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
55543e519524SHoward Hinnant    __debug_less<_Compare> __c(__comp);
55553e519524SHoward Hinnant    return __set_difference<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __c);
5556145afa17SHoward Hinnant#else  // _LIBCPP_DEBUG
55573e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
55583e519524SHoward Hinnant    return __set_difference<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __comp);
5559145afa17SHoward Hinnant#endif  // _LIBCPP_DEBUG
55603e519524SHoward Hinnant}
55613e519524SHoward Hinnant
55623e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _OutputIterator>
55633e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
55643e519524SHoward Hinnant_OutputIterator
55653e519524SHoward Hinnantset_difference(_InputIterator1 __first1, _InputIterator1 __last1,
55663e519524SHoward Hinnant               _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result)
55673e519524SHoward Hinnant{
5568ce48a113SHoward Hinnant    return _VSTD::set_difference(__first1, __last1, __first2, __last2, __result,
55693e519524SHoward Hinnant                                __less<typename iterator_traits<_InputIterator1>::value_type,
55703e519524SHoward Hinnant                                       typename iterator_traits<_InputIterator2>::value_type>());
55713e519524SHoward Hinnant}
55723e519524SHoward Hinnant
55733e519524SHoward Hinnant// set_symmetric_difference
55743e519524SHoward Hinnant
55753e519524SHoward Hinnanttemplate <class _Compare, class _InputIterator1, class _InputIterator2, class _OutputIterator>
55763e519524SHoward Hinnant_OutputIterator
55773e519524SHoward Hinnant__set_symmetric_difference(_InputIterator1 __first1, _InputIterator1 __last1,
55783e519524SHoward Hinnant                           _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
55793e519524SHoward Hinnant{
55803e519524SHoward Hinnant    while (__first1 != __last1)
55813e519524SHoward Hinnant    {
55823e519524SHoward Hinnant        if (__first2 == __last2)
5583ce48a113SHoward Hinnant            return _VSTD::copy(__first1, __last1, __result);
55843e519524SHoward Hinnant        if (__comp(*__first1, *__first2))
55853e519524SHoward Hinnant        {
55863e519524SHoward Hinnant            *__result = *__first1;
55873e519524SHoward Hinnant            ++__result;
55883e519524SHoward Hinnant            ++__first1;
55893e519524SHoward Hinnant        }
55903e519524SHoward Hinnant        else
55913e519524SHoward Hinnant        {
55923e519524SHoward Hinnant            if (__comp(*__first2, *__first1))
55933e519524SHoward Hinnant            {
55943e519524SHoward Hinnant                *__result = *__first2;
55953e519524SHoward Hinnant                ++__result;
55963e519524SHoward Hinnant            }
55973e519524SHoward Hinnant            else
55983e519524SHoward Hinnant                ++__first1;
55993e519524SHoward Hinnant            ++__first2;
56003e519524SHoward Hinnant        }
56013e519524SHoward Hinnant    }
5602ce48a113SHoward Hinnant    return _VSTD::copy(__first2, __last2, __result);
56033e519524SHoward Hinnant}
56043e519524SHoward Hinnant
56053e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
56063e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
56073e519524SHoward Hinnant_OutputIterator
56083e519524SHoward Hinnantset_symmetric_difference(_InputIterator1 __first1, _InputIterator1 __last1,
56093e519524SHoward Hinnant                         _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
56103e519524SHoward Hinnant{
5611145afa17SHoward Hinnant#ifdef _LIBCPP_DEBUG
56123e519524SHoward Hinnant    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
56133e519524SHoward Hinnant    __debug_less<_Compare> __c(__comp);
56143e519524SHoward Hinnant    return __set_symmetric_difference<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __c);
5615145afa17SHoward Hinnant#else  // _LIBCPP_DEBUG
56163e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
56173e519524SHoward Hinnant    return __set_symmetric_difference<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __comp);
5618145afa17SHoward Hinnant#endif  // _LIBCPP_DEBUG
56193e519524SHoward Hinnant}
56203e519524SHoward Hinnant
56213e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _OutputIterator>
56223e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
56233e519524SHoward Hinnant_OutputIterator
56243e519524SHoward Hinnantset_symmetric_difference(_InputIterator1 __first1, _InputIterator1 __last1,
56253e519524SHoward Hinnant                         _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result)
56263e519524SHoward Hinnant{
5627ce48a113SHoward Hinnant    return _VSTD::set_symmetric_difference(__first1, __last1, __first2, __last2, __result,
56283e519524SHoward Hinnant                                          __less<typename iterator_traits<_InputIterator1>::value_type,
56293e519524SHoward Hinnant                                                 typename iterator_traits<_InputIterator2>::value_type>());
56303e519524SHoward Hinnant}
56313e519524SHoward Hinnant
56323e519524SHoward Hinnant// lexicographical_compare
56333e519524SHoward Hinnant
56343e519524SHoward Hinnanttemplate <class _Compare, class _InputIterator1, class _InputIterator2>
56351b9a4ffdSMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
56363e519524SHoward Hinnant__lexicographical_compare(_InputIterator1 __first1, _InputIterator1 __last1,
56373e519524SHoward Hinnant                          _InputIterator2 __first2, _InputIterator2 __last2, _Compare __comp)
56383e519524SHoward Hinnant{
5639910285b2SEric Fiselier    for (; __first2 != __last2; ++__first1, (void) ++__first2)
56403e519524SHoward Hinnant    {
56413e519524SHoward Hinnant        if (__first1 == __last1 || __comp(*__first1, *__first2))
56423e519524SHoward Hinnant            return true;
56433e519524SHoward Hinnant        if (__comp(*__first2, *__first1))
56443e519524SHoward Hinnant            return false;
56453e519524SHoward Hinnant    }
56463e519524SHoward Hinnant    return false;
56473e519524SHoward Hinnant}
56483e519524SHoward Hinnant
56493e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _Compare>
5650*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
5651*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
56523e519524SHoward Hinnantbool
56533e519524SHoward Hinnantlexicographical_compare(_InputIterator1 __first1, _InputIterator1 __last1,
56543e519524SHoward Hinnant                        _InputIterator2 __first2, _InputIterator2 __last2, _Compare __comp)
56553e519524SHoward Hinnant{
5656145afa17SHoward Hinnant#ifdef _LIBCPP_DEBUG
56573e519524SHoward Hinnant    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
56583e519524SHoward Hinnant    __debug_less<_Compare> __c(__comp);
56593e519524SHoward Hinnant    return __lexicographical_compare<_Comp_ref>(__first1, __last1, __first2, __last2, __c);
5660145afa17SHoward Hinnant#else  // _LIBCPP_DEBUG
56613e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
56623e519524SHoward Hinnant    return __lexicographical_compare<_Comp_ref>(__first1, __last1, __first2, __last2, __comp);
5663145afa17SHoward Hinnant#endif  // _LIBCPP_DEBUG
56643e519524SHoward Hinnant}
56653e519524SHoward Hinnant
56663e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2>
5667*1362d7efSNico Weber_LIBCPP_NODISCARD_EXT inline
5668*1362d7efSNico Weber_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
56693e519524SHoward Hinnantbool
56703e519524SHoward Hinnantlexicographical_compare(_InputIterator1 __first1, _InputIterator1 __last1,
56713e519524SHoward Hinnant                        _InputIterator2 __first2, _InputIterator2 __last2)
56723e519524SHoward Hinnant{
5673ce48a113SHoward Hinnant    return _VSTD::lexicographical_compare(__first1, __last1, __first2, __last2,
56743e519524SHoward Hinnant                                         __less<typename iterator_traits<_InputIterator1>::value_type,
56753e519524SHoward Hinnant                                                typename iterator_traits<_InputIterator2>::value_type>());
56763e519524SHoward Hinnant}
56773e519524SHoward Hinnant
56783e519524SHoward Hinnant// next_permutation
56793e519524SHoward Hinnant
56803e519524SHoward Hinnanttemplate <class _Compare, class _BidirectionalIterator>
56813e519524SHoward Hinnantbool
56823e519524SHoward Hinnant__next_permutation(_BidirectionalIterator __first, _BidirectionalIterator __last, _Compare __comp)
56833e519524SHoward Hinnant{
56843e519524SHoward Hinnant    _BidirectionalIterator __i = __last;
56853e519524SHoward Hinnant    if (__first == __last || __first == --__i)
56863e519524SHoward Hinnant        return false;
56873e519524SHoward Hinnant    while (true)
56883e519524SHoward Hinnant    {
56893e519524SHoward Hinnant        _BidirectionalIterator __ip1 = __i;
56903e519524SHoward Hinnant        if (__comp(*--__i, *__ip1))
56913e519524SHoward Hinnant        {
56923e519524SHoward Hinnant            _BidirectionalIterator __j = __last;
56933e519524SHoward Hinnant            while (!__comp(*__i, *--__j))
56943e519524SHoward Hinnant                ;
56953e519524SHoward Hinnant            swap(*__i, *__j);
5696ce48a113SHoward Hinnant            _VSTD::reverse(__ip1, __last);
56973e519524SHoward Hinnant            return true;
56983e519524SHoward Hinnant        }
56993e519524SHoward Hinnant        if (__i == __first)
57003e519524SHoward Hinnant        {
5701ce48a113SHoward Hinnant            _VSTD::reverse(__first, __last);
57023e519524SHoward Hinnant            return false;
57033e519524SHoward Hinnant        }
57043e519524SHoward Hinnant    }
57053e519524SHoward Hinnant}
57063e519524SHoward Hinnant
57073e519524SHoward Hinnanttemplate <class _BidirectionalIterator, class _Compare>
57083e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
57093e519524SHoward Hinnantbool
57103e519524SHoward Hinnantnext_permutation(_BidirectionalIterator __first, _BidirectionalIterator __last, _Compare __comp)
57113e519524SHoward Hinnant{
5712145afa17SHoward Hinnant#ifdef _LIBCPP_DEBUG
57133e519524SHoward Hinnant    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
57143e519524SHoward Hinnant    __debug_less<_Compare> __c(__comp);
57153e519524SHoward Hinnant    return __next_permutation<_Comp_ref>(__first, __last, __c);
5716145afa17SHoward Hinnant#else  // _LIBCPP_DEBUG
57173e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
57183e519524SHoward Hinnant    return __next_permutation<_Comp_ref>(__first, __last, __comp);
5719145afa17SHoward Hinnant#endif  // _LIBCPP_DEBUG
57203e519524SHoward Hinnant}
57213e519524SHoward Hinnant
57223e519524SHoward Hinnanttemplate <class _BidirectionalIterator>
57233e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
57243e519524SHoward Hinnantbool
57253e519524SHoward Hinnantnext_permutation(_BidirectionalIterator __first, _BidirectionalIterator __last)
57263e519524SHoward Hinnant{
5727ce48a113SHoward Hinnant    return _VSTD::next_permutation(__first, __last,
57283e519524SHoward Hinnant                                  __less<typename iterator_traits<_BidirectionalIterator>::value_type>());
57293e519524SHoward Hinnant}
57303e519524SHoward Hinnant
57313e519524SHoward Hinnant// prev_permutation
57323e519524SHoward Hinnant
57333e519524SHoward Hinnanttemplate <class _Compare, class _BidirectionalIterator>
57343e519524SHoward Hinnantbool
57353e519524SHoward Hinnant__prev_permutation(_BidirectionalIterator __first, _BidirectionalIterator __last, _Compare __comp)
57363e519524SHoward Hinnant{
57373e519524SHoward Hinnant    _BidirectionalIterator __i = __last;
57383e519524SHoward Hinnant    if (__first == __last || __first == --__i)
57393e519524SHoward Hinnant        return false;
57403e519524SHoward Hinnant    while (true)
57413e519524SHoward Hinnant    {
57423e519524SHoward Hinnant        _BidirectionalIterator __ip1 = __i;
57433e519524SHoward Hinnant        if (__comp(*__ip1, *--__i))
57443e519524SHoward Hinnant        {
57453e519524SHoward Hinnant            _BidirectionalIterator __j = __last;
57463e519524SHoward Hinnant            while (!__comp(*--__j, *__i))
57473e519524SHoward Hinnant                ;
57483e519524SHoward Hinnant            swap(*__i, *__j);
5749ce48a113SHoward Hinnant            _VSTD::reverse(__ip1, __last);
57503e519524SHoward Hinnant            return true;
57513e519524SHoward Hinnant        }
57523e519524SHoward Hinnant        if (__i == __first)
57533e519524SHoward Hinnant        {
5754ce48a113SHoward Hinnant            _VSTD::reverse(__first, __last);
57553e519524SHoward Hinnant            return false;
57563e519524SHoward Hinnant        }
57573e519524SHoward Hinnant    }
57583e519524SHoward Hinnant}
57593e519524SHoward Hinnant
57603e519524SHoward Hinnanttemplate <class _BidirectionalIterator, class _Compare>
57613e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
57623e519524SHoward Hinnantbool
57633e519524SHoward Hinnantprev_permutation(_BidirectionalIterator __first, _BidirectionalIterator __last, _Compare __comp)
57643e519524SHoward Hinnant{
5765145afa17SHoward Hinnant#ifdef _LIBCPP_DEBUG
57663e519524SHoward Hinnant    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
57673e519524SHoward Hinnant    __debug_less<_Compare> __c(__comp);
57683e519524SHoward Hinnant    return __prev_permutation<_Comp_ref>(__first, __last, __c);
5769145afa17SHoward Hinnant#else  // _LIBCPP_DEBUG
57703e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
57713e519524SHoward Hinnant    return __prev_permutation<_Comp_ref>(__first, __last, __comp);
5772145afa17SHoward Hinnant#endif  // _LIBCPP_DEBUG
57733e519524SHoward Hinnant}
57743e519524SHoward Hinnant
57753e519524SHoward Hinnanttemplate <class _BidirectionalIterator>
57763e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
57773e519524SHoward Hinnantbool
57783e519524SHoward Hinnantprev_permutation(_BidirectionalIterator __first, _BidirectionalIterator __last)
57793e519524SHoward Hinnant{
5780ce48a113SHoward Hinnant    return _VSTD::prev_permutation(__first, __last,
57813e519524SHoward Hinnant                                  __less<typename iterator_traits<_BidirectionalIterator>::value_type>());
57823e519524SHoward Hinnant}
57833e519524SHoward Hinnant
57843e519524SHoward Hinnant_LIBCPP_END_NAMESPACE_STD
57853e519524SHoward Hinnant
5786a016efb1SEric Fiselier_LIBCPP_POP_MACROS
5787a016efb1SEric Fiselier
57883e519524SHoward Hinnant#endif  // _LIBCPP_ALGORITHM
5789