13e519524SHoward Hinnant// -*- C++ -*-
23e519524SHoward Hinnant//===-------------------------- algorithm ---------------------------------===//
33e519524SHoward Hinnant//
45b08a8a4SHoward Hinnant//                     The LLVM Compiler Infrastructure
53e519524SHoward Hinnant//
6412dbebeSHoward Hinnant// This file is dual licensed under the MIT and the University of Illinois Open
7412dbebeSHoward Hinnant// Source Licenses. See LICENSE.TXT for details.
83e519524SHoward Hinnant//
93e519524SHoward Hinnant//===----------------------------------------------------------------------===//
103e519524SHoward Hinnant
113e519524SHoward Hinnant#ifndef _LIBCPP_ALGORITHM
123e519524SHoward Hinnant#define _LIBCPP_ALGORITHM
133e519524SHoward Hinnant
143e519524SHoward Hinnant/*
153e519524SHoward Hinnant    algorithm synopsis
163e519524SHoward Hinnant
173e519524SHoward Hinnant#include <initializer_list>
183e519524SHoward Hinnant
193e519524SHoward Hinnantnamespace std
203e519524SHoward Hinnant{
213e519524SHoward Hinnant
223e519524SHoward Hinnanttemplate <class InputIterator, class Predicate>
23706ffef7SMarshall Clow    constexpr bool     // constexpr in C++20
243e519524SHoward Hinnant    all_of(InputIterator first, InputIterator last, Predicate pred);
253e519524SHoward Hinnant
263e519524SHoward Hinnanttemplate <class InputIterator, class Predicate>
27706ffef7SMarshall Clow    constexpr bool     // constexpr in C++20
283e519524SHoward Hinnant    any_of(InputIterator first, InputIterator last, Predicate pred);
293e519524SHoward Hinnant
303e519524SHoward Hinnanttemplate <class InputIterator, class Predicate>
31706ffef7SMarshall Clow    constexpr bool     // constexpr in C++20
323e519524SHoward Hinnant    none_of(InputIterator first, InputIterator last, Predicate pred);
333e519524SHoward Hinnant
343e519524SHoward Hinnanttemplate <class InputIterator, class Function>
351b9a4ffdSMarshall Clow    constexpr Function          // constexpr in C++20
363e519524SHoward Hinnant    for_each(InputIterator first, InputIterator last, Function f);
373e519524SHoward Hinnant
38d5c65ffaSMarshall Clowtemplate<class InputIterator, class Size, class Function>
391b9a4ffdSMarshall Clow    constexpr InputIterator     // constexpr in C++20
401b9a4ffdSMarshall Clow    for_each_n(InputIterator first, Size n, Function f); // C++17
41d5c65ffaSMarshall Clow
423e519524SHoward Hinnanttemplate <class InputIterator, class T>
4349c7643cSMarshall Clow    constexpr InputIterator     // constexpr in C++20
443e519524SHoward Hinnant    find(InputIterator first, InputIterator last, const T& value);
453e519524SHoward Hinnant
463e519524SHoward Hinnanttemplate <class InputIterator, class Predicate>
4749c7643cSMarshall Clow    constexpr InputIterator     // constexpr in C++20
483e519524SHoward Hinnant    find_if(InputIterator first, InputIterator last, Predicate pred);
493e519524SHoward Hinnant
503e519524SHoward Hinnanttemplate<class InputIterator, class Predicate>
518694428eSMarshall Clow    InputIterator               // constexpr in C++20
523e519524SHoward Hinnant    find_if_not(InputIterator first, InputIterator last, Predicate pred);
533e519524SHoward Hinnant
543e519524SHoward Hinnanttemplate <class ForwardIterator1, class ForwardIterator2>
558694428eSMarshall Clow    ForwardIterator1            // constexpr in C++20
563e519524SHoward Hinnant    find_end(ForwardIterator1 first1, ForwardIterator1 last1,
573e519524SHoward Hinnant             ForwardIterator2 first2, ForwardIterator2 last2);
583e519524SHoward Hinnant
593e519524SHoward Hinnanttemplate <class ForwardIterator1, class ForwardIterator2, class BinaryPredicate>
608694428eSMarshall Clow    ForwardIterator1            // constexpr in C++20
613e519524SHoward Hinnant    find_end(ForwardIterator1 first1, ForwardIterator1 last1,
623e519524SHoward Hinnant             ForwardIterator2 first2, ForwardIterator2 last2, BinaryPredicate pred);
633e519524SHoward Hinnant
643e519524SHoward Hinnanttemplate <class ForwardIterator1, class ForwardIterator2>
658694428eSMarshall Clow    constexpr ForwardIterator1  // constexpr in C++20
663e519524SHoward Hinnant    find_first_of(ForwardIterator1 first1, ForwardIterator1 last1,
673e519524SHoward Hinnant                  ForwardIterator2 first2, ForwardIterator2 last2);
683e519524SHoward Hinnant
693e519524SHoward Hinnanttemplate <class ForwardIterator1, class ForwardIterator2, class BinaryPredicate>
708694428eSMarshall Clow    constexpr ForwardIterator1  // constexpr in C++20
713e519524SHoward Hinnant    find_first_of(ForwardIterator1 first1, ForwardIterator1 last1,
723e519524SHoward Hinnant                  ForwardIterator2 first2, ForwardIterator2 last2, BinaryPredicate pred);
733e519524SHoward Hinnant
743e519524SHoward Hinnanttemplate <class ForwardIterator>
758694428eSMarshall Clow    constexpr ForwardIterator   // constexpr in C++20
763e519524SHoward Hinnant    adjacent_find(ForwardIterator first, ForwardIterator last);
773e519524SHoward Hinnant
783e519524SHoward Hinnanttemplate <class ForwardIterator, class BinaryPredicate>
798694428eSMarshall Clow    constexpr ForwardIterator   // constexpr in C++20
803e519524SHoward Hinnant    adjacent_find(ForwardIterator first, ForwardIterator last, BinaryPredicate pred);
813e519524SHoward Hinnant
823e519524SHoward Hinnanttemplate <class InputIterator, class T>
83056f15e3SMarshall Clow    constexpr typename iterator_traits<InputIterator>::difference_type  // constexpr in C++20
843e519524SHoward Hinnant    count(InputIterator first, InputIterator last, const T& value);
853e519524SHoward Hinnant
863e519524SHoward Hinnanttemplate <class InputIterator, class Predicate>
87056f15e3SMarshall Clow    constexpr typename iterator_traits<InputIterator>::difference_type // constexpr in C++20
883e519524SHoward Hinnant    count_if(InputIterator first, InputIterator last, Predicate pred);
893e519524SHoward Hinnant
903e519524SHoward Hinnanttemplate <class InputIterator1, class InputIterator2>
916538e28dSMarshall Clow    constexpr pair<InputIterator1, InputIterator2>   // constexpr in C++20
923e519524SHoward Hinnant    mismatch(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2);
933e519524SHoward Hinnant
940b0bbd2fSMarshall Clowtemplate <class InputIterator1, class InputIterator2>
956538e28dSMarshall Clow    constexpr pair<InputIterator1, InputIterator2>   // constexpr in C++20
960b0bbd2fSMarshall Clow    mismatch(InputIterator1 first1, InputIterator1 last1,
970b0bbd2fSMarshall Clow             InputIterator2 first2, InputIterator2 last2); // **C++14**
980b0bbd2fSMarshall Clow
993e519524SHoward Hinnanttemplate <class InputIterator1, class InputIterator2, class BinaryPredicate>
1006538e28dSMarshall Clow    constexpr pair<InputIterator1, InputIterator2>   // constexpr in C++20
1013e519524SHoward Hinnant    mismatch(InputIterator1 first1, InputIterator1 last1,
1023e519524SHoward Hinnant             InputIterator2 first2, BinaryPredicate pred);
1033e519524SHoward Hinnant
1040b0bbd2fSMarshall Clowtemplate <class InputIterator1, class InputIterator2, class BinaryPredicate>
1056538e28dSMarshall Clow    constexpr pair<InputIterator1, InputIterator2>   // constexpr in C++20
1060b0bbd2fSMarshall Clow    mismatch(InputIterator1 first1, InputIterator1 last1,
1070b0bbd2fSMarshall Clow             InputIterator2 first2, InputIterator2 last2,
1080b0bbd2fSMarshall Clow             BinaryPredicate pred); // **C++14**
1090b0bbd2fSMarshall Clow
1103e519524SHoward Hinnanttemplate <class InputIterator1, class InputIterator2>
1116538e28dSMarshall Clow    constexpr bool      // constexpr in C++20
1123e519524SHoward Hinnant    equal(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2);
1133e519524SHoward Hinnant
1140b0bbd2fSMarshall Clowtemplate <class InputIterator1, class InputIterator2>
1156538e28dSMarshall Clow    constexpr bool      // constexpr in C++20
1160b0bbd2fSMarshall Clow    equal(InputIterator1 first1, InputIterator1 last1,
1170b0bbd2fSMarshall Clow          InputIterator2 first2, InputIterator2 last2); // **C++14**
1180b0bbd2fSMarshall Clow
1193e519524SHoward Hinnanttemplate <class InputIterator1, class InputIterator2, class BinaryPredicate>
1206538e28dSMarshall Clow    constexpr bool      // constexpr in C++20
1213e519524SHoward Hinnant    equal(InputIterator1 first1, InputIterator1 last1,
1223e519524SHoward Hinnant          InputIterator2 first2, BinaryPredicate pred);
1233e519524SHoward Hinnant
1240b0bbd2fSMarshall Clowtemplate <class InputIterator1, class InputIterator2, class BinaryPredicate>
1256538e28dSMarshall Clow    constexpr bool      // constexpr in C++20
1260b0bbd2fSMarshall Clow    equal(InputIterator1 first1, InputIterator1 last1,
1270b0bbd2fSMarshall Clow          InputIterator2 first2, InputIterator2 last2,
1280b0bbd2fSMarshall Clow          BinaryPredicate pred); // **C++14**
1290b0bbd2fSMarshall Clow
1303e519524SHoward Hinnanttemplate<class ForwardIterator1, class ForwardIterator2>
13149c7643cSMarshall Clow    constexpr bool      // constexpr in C++20
1323e519524SHoward Hinnant    is_permutation(ForwardIterator1 first1, ForwardIterator1 last1,
1333e519524SHoward Hinnant                   ForwardIterator2 first2);
1343e519524SHoward Hinnant
1350b0bbd2fSMarshall Clowtemplate<class ForwardIterator1, class ForwardIterator2>
13649c7643cSMarshall Clow    constexpr bool      // constexpr in C++20
1370b0bbd2fSMarshall Clow    is_permutation(ForwardIterator1 first1, ForwardIterator1 last1,
1380b0bbd2fSMarshall Clow                   ForwardIterator2 first2, ForwardIterator2 last2); // **C++14**
1390b0bbd2fSMarshall Clow
1403e519524SHoward Hinnanttemplate<class ForwardIterator1, class ForwardIterator2, class BinaryPredicate>
14149c7643cSMarshall Clow    constexpr bool      // constexpr in C++20
1423e519524SHoward Hinnant    is_permutation(ForwardIterator1 first1, ForwardIterator1 last1,
1433e519524SHoward Hinnant                   ForwardIterator2 first2, BinaryPredicate pred);
1443e519524SHoward Hinnant
1450b0bbd2fSMarshall Clowtemplate<class ForwardIterator1, class ForwardIterator2, class BinaryPredicate>
14649c7643cSMarshall Clow    constexpr bool      // constexpr in C++20
1470b0bbd2fSMarshall Clow    is_permutation(ForwardIterator1 first1, ForwardIterator1 last1,
1480b0bbd2fSMarshall Clow                   ForwardIterator2 first2, ForwardIterator2 last2,
1490b0bbd2fSMarshall Clow                   BinaryPredicate pred);  // **C++14**
1500b0bbd2fSMarshall Clow
1513e519524SHoward Hinnanttemplate <class ForwardIterator1, class ForwardIterator2>
15212f0a779SMarshall Clow    constexpr ForwardIterator1      // constexpr in C++20
1533e519524SHoward Hinnant    search(ForwardIterator1 first1, ForwardIterator1 last1,
1543e519524SHoward Hinnant           ForwardIterator2 first2, ForwardIterator2 last2);
1553e519524SHoward Hinnant
1563e519524SHoward Hinnanttemplate <class ForwardIterator1, class ForwardIterator2, class BinaryPredicate>
15712f0a779SMarshall Clow    constexpr ForwardIterator1      // constexpr in C++20
1583e519524SHoward Hinnant    search(ForwardIterator1 first1, ForwardIterator1 last1,
1593e519524SHoward Hinnant           ForwardIterator2 first2, ForwardIterator2 last2, BinaryPredicate pred);
1603e519524SHoward Hinnant
1613e519524SHoward Hinnanttemplate <class ForwardIterator, class Size, class T>
16212f0a779SMarshall Clow    constexpr ForwardIterator       // constexpr in C++20
1633e519524SHoward Hinnant    search_n(ForwardIterator first, ForwardIterator last, Size count, const T& value);
1643e519524SHoward Hinnant
1653e519524SHoward Hinnanttemplate <class ForwardIterator, class Size, class T, class BinaryPredicate>
16612f0a779SMarshall Clow    constexpr ForwardIterator       // constexpr in C++20
1673e519524SHoward Hinnant    search_n(ForwardIterator first, ForwardIterator last,
1683e519524SHoward Hinnant             Size count, const T& value, BinaryPredicate pred);
1693e519524SHoward Hinnant
1703e519524SHoward Hinnanttemplate <class InputIterator, class OutputIterator>
1713e519524SHoward Hinnant    OutputIterator
1723e519524SHoward Hinnant    copy(InputIterator first, InputIterator last, OutputIterator result);
1733e519524SHoward Hinnant
1743e519524SHoward Hinnanttemplate<class InputIterator, class OutputIterator, class Predicate>
1753e519524SHoward Hinnant    OutputIterator
1763e519524SHoward Hinnant    copy_if(InputIterator first, InputIterator last,
1773e519524SHoward Hinnant            OutputIterator result, Predicate pred);
1783e519524SHoward Hinnant
1793e519524SHoward Hinnanttemplate<class InputIterator, class Size, class OutputIterator>
1803e519524SHoward Hinnant    OutputIterator
1813e519524SHoward Hinnant    copy_n(InputIterator first, Size n, OutputIterator result);
1823e519524SHoward Hinnant
1833e519524SHoward Hinnanttemplate <class BidirectionalIterator1, class BidirectionalIterator2>
1843e519524SHoward Hinnant    BidirectionalIterator2
1853e519524SHoward Hinnant    copy_backward(BidirectionalIterator1 first, BidirectionalIterator1 last,
1863e519524SHoward Hinnant                  BidirectionalIterator2 result);
1873e519524SHoward Hinnant
1883e519524SHoward Hinnanttemplate <class ForwardIterator1, class ForwardIterator2>
1893e519524SHoward Hinnant    ForwardIterator2
1903e519524SHoward Hinnant    swap_ranges(ForwardIterator1 first1, ForwardIterator1 last1, ForwardIterator2 first2);
1913e519524SHoward Hinnant
1923e519524SHoward Hinnanttemplate <class ForwardIterator1, class ForwardIterator2>
1933e519524SHoward Hinnant    void
1943e519524SHoward Hinnant    iter_swap(ForwardIterator1 a, ForwardIterator2 b);
1953e519524SHoward Hinnant
1963e519524SHoward Hinnanttemplate <class InputIterator, class OutputIterator, class UnaryOperation>
19799894b61SMarshall Clow    constexpr OutputIterator      // constexpr in C++20
1983e519524SHoward Hinnant    transform(InputIterator first, InputIterator last, OutputIterator result, UnaryOperation op);
1993e519524SHoward Hinnant
2003e519524SHoward Hinnanttemplate <class InputIterator1, class InputIterator2, class OutputIterator, class BinaryOperation>
20199894b61SMarshall Clow    constexpr OutputIterator      // constexpr in C++20
2023e519524SHoward Hinnant    transform(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2,
2033e519524SHoward Hinnant              OutputIterator result, BinaryOperation binary_op);
2043e519524SHoward Hinnant
2053e519524SHoward Hinnanttemplate <class ForwardIterator, class T>
20612c7423fSMarshall Clow    constexpr void      // constexpr in C++20
2073e519524SHoward Hinnant    replace(ForwardIterator first, ForwardIterator last, const T& old_value, const T& new_value);
2083e519524SHoward Hinnant
2093e519524SHoward Hinnanttemplate <class ForwardIterator, class Predicate, class T>
21012c7423fSMarshall Clow    constexpr void      // constexpr in C++20
2113e519524SHoward Hinnant    replace_if(ForwardIterator first, ForwardIterator last, Predicate pred, const T& new_value);
2123e519524SHoward Hinnant
2133e519524SHoward Hinnanttemplate <class InputIterator, class OutputIterator, class T>
21412c7423fSMarshall Clow    constexpr OutputIterator      // constexpr in C++20
2153e519524SHoward Hinnant    replace_copy(InputIterator first, InputIterator last, OutputIterator result,
2163e519524SHoward Hinnant                 const T& old_value, const T& new_value);
2173e519524SHoward Hinnant
2183e519524SHoward Hinnanttemplate <class InputIterator, class OutputIterator, class Predicate, class T>
21912c7423fSMarshall Clow    constexpr OutputIterator      // constexpr in C++20
2203e519524SHoward Hinnant    replace_copy_if(InputIterator first, InputIterator last, OutputIterator result, Predicate pred, const T& new_value);
2213e519524SHoward Hinnant
2223e519524SHoward Hinnanttemplate <class ForwardIterator, class T>
2234bfb9313SMarshall Clow    constexpr void      // constexpr in C++20
2243e519524SHoward Hinnant    fill(ForwardIterator first, ForwardIterator last, const T& value);
2253e519524SHoward Hinnant
2263e519524SHoward Hinnanttemplate <class OutputIterator, class Size, class T>
2274bfb9313SMarshall Clow    constexpr OutputIterator      // constexpr in C++20
2283e519524SHoward Hinnant    fill_n(OutputIterator first, Size n, const T& value);
2293e519524SHoward Hinnant
2303e519524SHoward Hinnanttemplate <class ForwardIterator, class Generator>
2314bfb9313SMarshall Clow    constexpr void      // constexpr in C++20
2323e519524SHoward Hinnant    generate(ForwardIterator first, ForwardIterator last, Generator gen);
2333e519524SHoward Hinnant
2343e519524SHoward Hinnanttemplate <class OutputIterator, class Size, class Generator>
2354bfb9313SMarshall Clow    constexpr OutputIterator      // constexpr in C++20
2363e519524SHoward Hinnant    generate_n(OutputIterator first, Size n, Generator gen);
2373e519524SHoward Hinnant
2383e519524SHoward Hinnanttemplate <class ForwardIterator, class T>
239e8ea8296SMarshall Clow    constexpr ForwardIterator     // constexpr in C++20
2403e519524SHoward Hinnant    remove(ForwardIterator first, ForwardIterator last, const T& value);
2413e519524SHoward Hinnant
2423e519524SHoward Hinnanttemplate <class ForwardIterator, class Predicate>
243e8ea8296SMarshall Clow    constexpr ForwardIterator     // constexpr in C++20
2443e519524SHoward Hinnant    remove_if(ForwardIterator first, ForwardIterator last, Predicate pred);
2453e519524SHoward Hinnant
2463e519524SHoward Hinnanttemplate <class InputIterator, class OutputIterator, class T>
247e8ea8296SMarshall Clow    constexpr OutputIterator     // constexpr in C++20
2483e519524SHoward Hinnant    remove_copy(InputIterator first, InputIterator last, OutputIterator result, const T& value);
2493e519524SHoward Hinnant
2503e519524SHoward Hinnanttemplate <class InputIterator, class OutputIterator, class Predicate>
251e8ea8296SMarshall Clow    constexpr OutputIterator     // constexpr in C++20
2523e519524SHoward Hinnant    remove_copy_if(InputIterator first, InputIterator last, OutputIterator result, Predicate pred);
2533e519524SHoward Hinnant
2543e519524SHoward Hinnanttemplate <class ForwardIterator>
2553e519524SHoward Hinnant    ForwardIterator
2563e519524SHoward Hinnant    unique(ForwardIterator first, ForwardIterator last);
2573e519524SHoward Hinnant
2583e519524SHoward Hinnanttemplate <class ForwardIterator, class BinaryPredicate>
2593e519524SHoward Hinnant    ForwardIterator
2603e519524SHoward Hinnant    unique(ForwardIterator first, ForwardIterator last, BinaryPredicate pred);
2613e519524SHoward Hinnant
2623e519524SHoward Hinnanttemplate <class InputIterator, class OutputIterator>
2633e519524SHoward Hinnant    OutputIterator
2643e519524SHoward Hinnant    unique_copy(InputIterator first, InputIterator last, OutputIterator result);
2653e519524SHoward Hinnant
2663e519524SHoward Hinnanttemplate <class InputIterator, class OutputIterator, class BinaryPredicate>
2673e519524SHoward Hinnant    OutputIterator
2683e519524SHoward Hinnant    unique_copy(InputIterator first, InputIterator last, OutputIterator result, BinaryPredicate pred);
2693e519524SHoward Hinnant
2703e519524SHoward Hinnanttemplate <class BidirectionalIterator>
2713e519524SHoward Hinnant    void
2723e519524SHoward Hinnant    reverse(BidirectionalIterator first, BidirectionalIterator last);
2733e519524SHoward Hinnant
2743e519524SHoward Hinnanttemplate <class BidirectionalIterator, class OutputIterator>
275e8ea8296SMarshall Clow    constexpr OutputIterator       // constexpr in C++20
2763e519524SHoward Hinnant    reverse_copy(BidirectionalIterator first, BidirectionalIterator last, OutputIterator result);
2773e519524SHoward Hinnant
2783e519524SHoward Hinnanttemplate <class ForwardIterator>
2793e519524SHoward Hinnant    ForwardIterator
2803e519524SHoward Hinnant    rotate(ForwardIterator first, ForwardIterator middle, ForwardIterator last);
2813e519524SHoward Hinnant
2823e519524SHoward Hinnanttemplate <class ForwardIterator, class OutputIterator>
2833e519524SHoward Hinnant    OutputIterator
2843e519524SHoward Hinnant    rotate_copy(ForwardIterator first, ForwardIterator middle, ForwardIterator last, OutputIterator result);
2853e519524SHoward Hinnant
2863e519524SHoward Hinnanttemplate <class RandomAccessIterator>
2873e519524SHoward Hinnant    void
2880f37a410SMarshall Clow    random_shuffle(RandomAccessIterator first, RandomAccessIterator last); // deprecated in C++14, removed in C++17
2893e519524SHoward Hinnant
2903e519524SHoward Hinnanttemplate <class RandomAccessIterator, class RandomNumberGenerator>
2913e519524SHoward Hinnant    void
29206965c1fSMarshall Clow    random_shuffle(RandomAccessIterator first, RandomAccessIterator last,
2930f37a410SMarshall Clow                   RandomNumberGenerator& rand);  // deprecated in C++14, removed in C++17
2943e519524SHoward Hinnant
295e7154709SEric Fiseliertemplate<class PopulationIterator, class SampleIterator,
296e7154709SEric Fiselier         class Distance, class UniformRandomBitGenerator>
297e7154709SEric Fiselier    SampleIterator sample(PopulationIterator first, PopulationIterator last,
298e7154709SEric Fiselier                          SampleIterator out, Distance n,
299e7154709SEric Fiselier                          UniformRandomBitGenerator&& g); // C++17
300e7154709SEric Fiselier
301f9d540b0SHoward Hinnanttemplate<class RandomAccessIterator, class UniformRandomNumberGenerator>
302f9d540b0SHoward Hinnant    void shuffle(RandomAccessIterator first, RandomAccessIterator last,
303fb340102SHoward Hinnant                 UniformRandomNumberGenerator&& g);
304f9d540b0SHoward Hinnant
3053e519524SHoward Hinnanttemplate <class InputIterator, class Predicate>
30649c7643cSMarshall Clow    constexpr bool  // constexpr in C++20
3073e519524SHoward Hinnant    is_partitioned(InputIterator first, InputIterator last, Predicate pred);
3083e519524SHoward Hinnant
3093e519524SHoward Hinnanttemplate <class ForwardIterator, class Predicate>
3103e519524SHoward Hinnant    ForwardIterator
3113e519524SHoward Hinnant    partition(ForwardIterator first, ForwardIterator last, Predicate pred);
3123e519524SHoward Hinnant
3133e519524SHoward Hinnanttemplate <class InputIterator, class OutputIterator1,
3143e519524SHoward Hinnant          class OutputIterator2, class Predicate>
3151b9a4ffdSMarshall Clow    constexpr pair<OutputIterator1, OutputIterator2>   // constexpr in C++20
3163e519524SHoward Hinnant    partition_copy(InputIterator first, InputIterator last,
3173e519524SHoward Hinnant                   OutputIterator1 out_true, OutputIterator2 out_false,
3183e519524SHoward Hinnant                   Predicate pred);
3193e519524SHoward Hinnant
3203e519524SHoward Hinnanttemplate <class ForwardIterator, class Predicate>
3213e519524SHoward Hinnant    ForwardIterator
3223e519524SHoward Hinnant    stable_partition(ForwardIterator first, ForwardIterator last, Predicate pred);
3233e519524SHoward Hinnant
3243e519524SHoward Hinnanttemplate<class ForwardIterator, class Predicate>
325d57c03ddSMarshall Clow    constexpr ForwardIterator  // constexpr in C++20
3263e519524SHoward Hinnant    partition_point(ForwardIterator first, ForwardIterator last, Predicate pred);
3273e519524SHoward Hinnant
3283e519524SHoward Hinnanttemplate <class ForwardIterator>
32949c7643cSMarshall Clow    constexpr bool  // constexpr in C++20
3303e519524SHoward Hinnant    is_sorted(ForwardIterator first, ForwardIterator last);
3313e519524SHoward Hinnant
3323e519524SHoward Hinnanttemplate <class ForwardIterator, class Compare>
3333e519524SHoward Hinnant    bool
3343e519524SHoward Hinnant    is_sorted(ForwardIterator first, ForwardIterator last, Compare comp);
3353e519524SHoward Hinnant
3363e519524SHoward Hinnanttemplate<class ForwardIterator>
337056f15e3SMarshall Clow    constexpr ForwardIterator    // constexpr in C++20
3383e519524SHoward Hinnant    is_sorted_until(ForwardIterator first, ForwardIterator last);
3393e519524SHoward Hinnant
3403e519524SHoward Hinnanttemplate <class ForwardIterator, class Compare>
341056f15e3SMarshall Clow    constexpr ForwardIterator    // constexpr in C++20
3423e519524SHoward Hinnant    is_sorted_until(ForwardIterator first, ForwardIterator last, Compare comp);
3433e519524SHoward Hinnant
3443e519524SHoward Hinnanttemplate <class RandomAccessIterator>
3453e519524SHoward Hinnant    void
3463e519524SHoward Hinnant    sort(RandomAccessIterator first, RandomAccessIterator last);
3473e519524SHoward Hinnant
3483e519524SHoward Hinnanttemplate <class RandomAccessIterator, class Compare>
3493e519524SHoward Hinnant    void
3503e519524SHoward Hinnant    sort(RandomAccessIterator first, RandomAccessIterator last, Compare comp);
3513e519524SHoward Hinnant
3523e519524SHoward Hinnanttemplate <class RandomAccessIterator>
3533e519524SHoward Hinnant    void
3543e519524SHoward Hinnant    stable_sort(RandomAccessIterator first, RandomAccessIterator last);
3553e519524SHoward Hinnant
3563e519524SHoward Hinnanttemplate <class RandomAccessIterator, class Compare>
3573e519524SHoward Hinnant    void
3583e519524SHoward Hinnant    stable_sort(RandomAccessIterator first, RandomAccessIterator last, Compare comp);
3593e519524SHoward Hinnant
3603e519524SHoward Hinnanttemplate <class RandomAccessIterator>
3613e519524SHoward Hinnant    void
3623e519524SHoward Hinnant    partial_sort(RandomAccessIterator first, RandomAccessIterator middle, RandomAccessIterator last);
3633e519524SHoward Hinnant
3643e519524SHoward Hinnanttemplate <class RandomAccessIterator, class Compare>
3653e519524SHoward Hinnant    void
3663e519524SHoward Hinnant    partial_sort(RandomAccessIterator first, RandomAccessIterator middle, RandomAccessIterator last, Compare comp);
3673e519524SHoward Hinnant
3683e519524SHoward Hinnanttemplate <class InputIterator, class RandomAccessIterator>
3693e519524SHoward Hinnant    RandomAccessIterator
3703e519524SHoward Hinnant    partial_sort_copy(InputIterator first, InputIterator last,
3713e519524SHoward Hinnant                      RandomAccessIterator result_first, RandomAccessIterator result_last);
3723e519524SHoward Hinnant
3733e519524SHoward Hinnanttemplate <class InputIterator, class RandomAccessIterator, class Compare>
3743e519524SHoward Hinnant    RandomAccessIterator
3753e519524SHoward Hinnant    partial_sort_copy(InputIterator first, InputIterator last,
3763e519524SHoward Hinnant                      RandomAccessIterator result_first, RandomAccessIterator result_last, Compare comp);
3773e519524SHoward Hinnant
3783e519524SHoward Hinnanttemplate <class RandomAccessIterator>
3793e519524SHoward Hinnant    void
3803e519524SHoward Hinnant    nth_element(RandomAccessIterator first, RandomAccessIterator nth, RandomAccessIterator last);
3813e519524SHoward Hinnant
3823e519524SHoward Hinnanttemplate <class RandomAccessIterator, class Compare>
3833e519524SHoward Hinnant    void
3843e519524SHoward Hinnant    nth_element(RandomAccessIterator first, RandomAccessIterator nth, RandomAccessIterator last, Compare comp);
3853e519524SHoward Hinnant
3863e519524SHoward Hinnanttemplate <class ForwardIterator, class T>
387d57c03ddSMarshall Clow    constexpr ForwardIterator                         // constexpr in C++20
3883e519524SHoward Hinnant    lower_bound(ForwardIterator first, ForwardIterator last, const T& value);
3893e519524SHoward Hinnant
3903e519524SHoward Hinnanttemplate <class ForwardIterator, class T, class Compare>
391d57c03ddSMarshall Clow    constexpr ForwardIterator                         // constexpr in C++20
3923e519524SHoward Hinnant    lower_bound(ForwardIterator first, ForwardIterator last, const T& value, Compare comp);
3933e519524SHoward Hinnant
3943e519524SHoward Hinnanttemplate <class ForwardIterator, class T>
395d57c03ddSMarshall Clow    constexpr ForwardIterator                         // constexpr in C++20
3963e519524SHoward Hinnant    upper_bound(ForwardIterator first, ForwardIterator last, const T& value);
3973e519524SHoward Hinnant
3983e519524SHoward Hinnanttemplate <class ForwardIterator, class T, class Compare>
399d57c03ddSMarshall Clow    constexpr ForwardIterator                         // constexpr in C++20
4003e519524SHoward Hinnant    upper_bound(ForwardIterator first, ForwardIterator last, const T& value, Compare comp);
4013e519524SHoward Hinnant
4023e519524SHoward Hinnanttemplate <class ForwardIterator, class T>
403d57c03ddSMarshall Clow    constexpr pair<ForwardIterator, ForwardIterator>  // constexpr in C++20
4043e519524SHoward Hinnant    equal_range(ForwardIterator first, ForwardIterator last, const T& value);
4053e519524SHoward Hinnant
4063e519524SHoward Hinnanttemplate <class ForwardIterator, class T, class Compare>
407d57c03ddSMarshall Clow    constexpr pair<ForwardIterator, ForwardIterator>  // constexpr in C++20
4083e519524SHoward Hinnant    equal_range(ForwardIterator first, ForwardIterator last, const T& value, Compare comp);
4093e519524SHoward Hinnant
4103e519524SHoward Hinnanttemplate <class ForwardIterator, class T>
411d57c03ddSMarshall Clow    constexpr bool                                    // constexpr in C++20
4123e519524SHoward Hinnant    binary_search(ForwardIterator first, ForwardIterator last, const T& value);
4133e519524SHoward Hinnant
4143e519524SHoward Hinnanttemplate <class ForwardIterator, class T, class Compare>
4158da1a487SMarshall Clow    constexpr bool                                    // constexpr in C++20
4163e519524SHoward Hinnant    binary_search(ForwardIterator first, ForwardIterator last, const T& value, Compare comp);
4173e519524SHoward Hinnant
4183e519524SHoward Hinnanttemplate <class InputIterator1, class InputIterator2, class OutputIterator>
4193e519524SHoward Hinnant    OutputIterator
4203e519524SHoward Hinnant    merge(InputIterator1 first1, InputIterator1 last1,
4213e519524SHoward Hinnant          InputIterator2 first2, InputIterator2 last2, OutputIterator result);
4223e519524SHoward Hinnant
4233e519524SHoward Hinnanttemplate <class InputIterator1, class InputIterator2, class OutputIterator, class Compare>
4243e519524SHoward Hinnant    OutputIterator
4253e519524SHoward Hinnant    merge(InputIterator1 first1, InputIterator1 last1,
4263e519524SHoward Hinnant          InputIterator2 first2, InputIterator2 last2, OutputIterator result, Compare comp);
4273e519524SHoward Hinnant
4283e519524SHoward Hinnanttemplate <class BidirectionalIterator>
4293e519524SHoward Hinnant    void
4303e519524SHoward Hinnant    inplace_merge(BidirectionalIterator first, BidirectionalIterator middle, BidirectionalIterator last);
4313e519524SHoward Hinnant
4323e519524SHoward Hinnanttemplate <class BidirectionalIterator, class Compare>
4333e519524SHoward Hinnant    void
4343e519524SHoward Hinnant    inplace_merge(BidirectionalIterator first, BidirectionalIterator middle, BidirectionalIterator last, Compare comp);
4353e519524SHoward Hinnant
4363e519524SHoward Hinnanttemplate <class InputIterator1, class InputIterator2>
4378da1a487SMarshall Clow    constexpr bool                                    // constexpr in C++20
4383e519524SHoward Hinnant    includes(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, InputIterator2 last2);
4393e519524SHoward Hinnant
4403e519524SHoward Hinnanttemplate <class InputIterator1, class InputIterator2, class Compare>
4418da1a487SMarshall Clow    constexpr bool                                    // constexpr in C++20
4423e519524SHoward Hinnant    includes(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, InputIterator2 last2, Compare comp);
4433e519524SHoward Hinnant
4443e519524SHoward Hinnanttemplate <class InputIterator1, class InputIterator2, class OutputIterator>
4453e519524SHoward Hinnant    OutputIterator
4463e519524SHoward Hinnant    set_union(InputIterator1 first1, InputIterator1 last1,
4473e519524SHoward Hinnant              InputIterator2 first2, InputIterator2 last2, OutputIterator result);
4483e519524SHoward Hinnant
4493e519524SHoward Hinnanttemplate <class InputIterator1, class InputIterator2, class OutputIterator, class Compare>
4503e519524SHoward Hinnant    OutputIterator
4513e519524SHoward Hinnant    set_union(InputIterator1 first1, InputIterator1 last1,
4523e519524SHoward Hinnant              InputIterator2 first2, InputIterator2 last2, OutputIterator result, Compare comp);
4533e519524SHoward Hinnant
4543e519524SHoward Hinnanttemplate <class InputIterator1, class InputIterator2, class OutputIterator>
4558da1a487SMarshall Clow    constexpr OutputIterator                         // constexpr in C++20
4563e519524SHoward Hinnant    set_intersection(InputIterator1 first1, InputIterator1 last1,
4573e519524SHoward Hinnant                     InputIterator2 first2, InputIterator2 last2, OutputIterator result);
4583e519524SHoward Hinnant
4593e519524SHoward Hinnanttemplate <class InputIterator1, class InputIterator2, class OutputIterator, class Compare>
4608da1a487SMarshall Clow    constexpr OutputIterator                         // constexpr in C++20
4613e519524SHoward Hinnant    set_intersection(InputIterator1 first1, InputIterator1 last1,
4623e519524SHoward Hinnant                     InputIterator2 first2, InputIterator2 last2, OutputIterator result, Compare comp);
4633e519524SHoward Hinnant
4643e519524SHoward Hinnanttemplate <class InputIterator1, class InputIterator2, class OutputIterator>
4653e519524SHoward Hinnant    OutputIterator
4663e519524SHoward Hinnant    set_difference(InputIterator1 first1, InputIterator1 last1,
4673e519524SHoward Hinnant                   InputIterator2 first2, InputIterator2 last2, OutputIterator result);
4683e519524SHoward Hinnant
4693e519524SHoward Hinnanttemplate <class InputIterator1, class InputIterator2, class OutputIterator, class Compare>
4703e519524SHoward Hinnant    OutputIterator
4713e519524SHoward Hinnant    set_difference(InputIterator1 first1, InputIterator1 last1,
4723e519524SHoward Hinnant                   InputIterator2 first2, InputIterator2 last2, OutputIterator result, Compare comp);
4733e519524SHoward Hinnant
4743e519524SHoward Hinnanttemplate <class InputIterator1, class InputIterator2, class OutputIterator>
4753e519524SHoward Hinnant    OutputIterator
4763e519524SHoward Hinnant    set_symmetric_difference(InputIterator1 first1, InputIterator1 last1,
4773e519524SHoward Hinnant                             InputIterator2 first2, InputIterator2 last2, OutputIterator result);
4783e519524SHoward Hinnant
4793e519524SHoward Hinnanttemplate <class InputIterator1, class InputIterator2, class OutputIterator, class Compare>
4803e519524SHoward Hinnant    OutputIterator
4813e519524SHoward Hinnant    set_symmetric_difference(InputIterator1 first1, InputIterator1 last1,
4823e519524SHoward Hinnant                             InputIterator2 first2, InputIterator2 last2, OutputIterator result, Compare comp);
4833e519524SHoward Hinnant
4843e519524SHoward Hinnanttemplate <class RandomAccessIterator>
4853e519524SHoward Hinnant    void
4863e519524SHoward Hinnant    push_heap(RandomAccessIterator first, RandomAccessIterator last);
4873e519524SHoward Hinnant
4883e519524SHoward Hinnanttemplate <class RandomAccessIterator, class Compare>
4893e519524SHoward Hinnant    void
4903e519524SHoward Hinnant    push_heap(RandomAccessIterator first, RandomAccessIterator last, Compare comp);
4913e519524SHoward Hinnant
4923e519524SHoward Hinnanttemplate <class RandomAccessIterator>
4933e519524SHoward Hinnant    void
4943e519524SHoward Hinnant    pop_heap(RandomAccessIterator first, RandomAccessIterator last);
4953e519524SHoward Hinnant
4963e519524SHoward Hinnanttemplate <class RandomAccessIterator, class Compare>
4973e519524SHoward Hinnant    void
4983e519524SHoward Hinnant    pop_heap(RandomAccessIterator first, RandomAccessIterator last, Compare comp);
4993e519524SHoward Hinnant
5003e519524SHoward Hinnanttemplate <class RandomAccessIterator>
5013e519524SHoward Hinnant    void
5023e519524SHoward Hinnant    make_heap(RandomAccessIterator first, RandomAccessIterator last);
5033e519524SHoward Hinnant
5043e519524SHoward Hinnanttemplate <class RandomAccessIterator, class Compare>
5053e519524SHoward Hinnant    void
5063e519524SHoward Hinnant    make_heap(RandomAccessIterator first, RandomAccessIterator last, Compare comp);
5073e519524SHoward Hinnant
5083e519524SHoward Hinnanttemplate <class RandomAccessIterator>
5093e519524SHoward Hinnant    void
5103e519524SHoward Hinnant    sort_heap(RandomAccessIterator first, RandomAccessIterator last);
5113e519524SHoward Hinnant
5123e519524SHoward Hinnanttemplate <class RandomAccessIterator, class Compare>
5133e519524SHoward Hinnant    void
5143e519524SHoward Hinnant    sort_heap(RandomAccessIterator first, RandomAccessIterator last, Compare comp);
5153e519524SHoward Hinnant
5163e519524SHoward Hinnanttemplate <class RandomAccessIterator>
51749c7643cSMarshall Clow    constexpr bool   // constexpr in C++20
5183e519524SHoward Hinnant    is_heap(RandomAccessIterator first, RandomAccessiterator last);
5193e519524SHoward Hinnant
5203e519524SHoward Hinnanttemplate <class RandomAccessIterator, class Compare>
52149c7643cSMarshall Clow    constexpr bool   // constexpr in C++20
5223e519524SHoward Hinnant    is_heap(RandomAccessIterator first, RandomAccessiterator last, Compare comp);
5233e519524SHoward Hinnant
5243e519524SHoward Hinnanttemplate <class RandomAccessIterator>
52549c7643cSMarshall Clow    constexpr RandomAccessIterator   // constexpr in C++20
5263e519524SHoward Hinnant    is_heap_until(RandomAccessIterator first, RandomAccessiterator last);
5273e519524SHoward Hinnant
5283e519524SHoward Hinnanttemplate <class RandomAccessIterator, class Compare>
52949c7643cSMarshall Clow    constexpr RandomAccessIterator   // constexpr in C++20
5303e519524SHoward Hinnant    is_heap_until(RandomAccessIterator first, RandomAccessiterator last, Compare comp);
5313e519524SHoward Hinnant
5324eb27b79SHoward Hinnanttemplate <class ForwardIterator>
5334eb27b79SHoward Hinnant    ForwardIterator
5340b0671aeSMarshall Clow    min_element(ForwardIterator first, ForwardIterator last);  // constexpr in C++14
5354eb27b79SHoward Hinnant
5364eb27b79SHoward Hinnanttemplate <class ForwardIterator, class Compare>
5374eb27b79SHoward Hinnant    ForwardIterator
5380b0671aeSMarshall Clow    min_element(ForwardIterator first, ForwardIterator last, Compare comp);  // constexpr in C++14
5394eb27b79SHoward Hinnant
5403e519524SHoward Hinnanttemplate <class T>
5413e519524SHoward Hinnant    const T&
5429d67c6d5SMarshall Clow    min(const T& a, const T& b);  // constexpr in C++14
5433e519524SHoward Hinnant
5443e519524SHoward Hinnanttemplate <class T, class Compare>
5453e519524SHoward Hinnant    const T&
5469d67c6d5SMarshall Clow    min(const T& a, const T& b, Compare comp);  // constexpr in C++14
5473e519524SHoward Hinnant
5483e519524SHoward Hinnanttemplate<class T>
5494eb27b79SHoward Hinnant    T
5509d67c6d5SMarshall Clow    min(initializer_list<T> t);  // constexpr in C++14
5513e519524SHoward Hinnant
5523e519524SHoward Hinnanttemplate<class T, class Compare>
5534eb27b79SHoward Hinnant    T
5549d67c6d5SMarshall Clow    min(initializer_list<T> t, Compare comp);  // constexpr in C++14
5553e519524SHoward Hinnant
556146c14acSMarshall Clowtemplate<class T>
557146c14acSMarshall Clow    constexpr const T& clamp( const T& v, const T& lo, const T& hi );               // C++17
558146c14acSMarshall Clow
559146c14acSMarshall Clowtemplate<class T, class Compare>
560146c14acSMarshall Clow    constexpr const T& clamp( const T& v, const T& lo, const T& hi, Compare comp ); // C++17
561146c14acSMarshall Clow
5623e519524SHoward Hinnanttemplate <class ForwardIterator>
5633e519524SHoward Hinnant    ForwardIterator
5640b0671aeSMarshall Clow    max_element(ForwardIterator first, ForwardIterator last);  // constexpr in C++14
5653e519524SHoward Hinnant
5663e519524SHoward Hinnanttemplate <class ForwardIterator, class Compare>
5673e519524SHoward Hinnant    ForwardIterator
5680b0671aeSMarshall Clow    max_element(ForwardIterator first, ForwardIterator last, Compare comp);  // constexpr in C++14
5693e519524SHoward Hinnant
5704eb27b79SHoward Hinnanttemplate <class T>
5714eb27b79SHoward Hinnant    const T&
5729d67c6d5SMarshall Clow    max(const T& a, const T& b); // constexpr in C++14
5734eb27b79SHoward Hinnant
5744eb27b79SHoward Hinnanttemplate <class T, class Compare>
5754eb27b79SHoward Hinnant    const T&
5769d67c6d5SMarshall Clow    max(const T& a, const T& b, Compare comp);  // constexpr in C++14
5774eb27b79SHoward Hinnant
5784eb27b79SHoward Hinnanttemplate<class T>
5794eb27b79SHoward Hinnant    T
5809d67c6d5SMarshall Clow    max(initializer_list<T> t);  // constexpr in C++14
5814eb27b79SHoward Hinnant
5824eb27b79SHoward Hinnanttemplate<class T, class Compare>
5834eb27b79SHoward Hinnant    T
5849d67c6d5SMarshall Clow    max(initializer_list<T> t, Compare comp);  // constexpr in C++14
5854eb27b79SHoward Hinnant
5864eb27b79SHoward Hinnanttemplate<class ForwardIterator>
5874eb27b79SHoward Hinnant    pair<ForwardIterator, ForwardIterator>
5880b0671aeSMarshall Clow    minmax_element(ForwardIterator first, ForwardIterator last);   // constexpr in C++14
5894eb27b79SHoward Hinnant
5904eb27b79SHoward Hinnanttemplate<class ForwardIterator, class Compare>
5914eb27b79SHoward Hinnant    pair<ForwardIterator, ForwardIterator>
5920b0671aeSMarshall Clow    minmax_element(ForwardIterator first, ForwardIterator last, Compare comp);   // constexpr in C++14
5934eb27b79SHoward Hinnant
5944eb27b79SHoward Hinnanttemplate<class T>
5954eb27b79SHoward Hinnant    pair<const T&, const T&>
5969d67c6d5SMarshall Clow    minmax(const T& a, const T& b);  // constexpr in C++14
5974eb27b79SHoward Hinnant
5984eb27b79SHoward Hinnanttemplate<class T, class Compare>
5994eb27b79SHoward Hinnant    pair<const T&, const T&>
6009d67c6d5SMarshall Clow    minmax(const T& a, const T& b, Compare comp);  // constexpr in C++14
6014eb27b79SHoward Hinnant
6024eb27b79SHoward Hinnanttemplate<class T>
6034eb27b79SHoward Hinnant    pair<T, T>
6049d67c6d5SMarshall Clow    minmax(initializer_list<T> t);  // constexpr in C++14
6054eb27b79SHoward Hinnant
6064eb27b79SHoward Hinnanttemplate<class T, class Compare>
6074eb27b79SHoward Hinnant    pair<T, T>
6089d67c6d5SMarshall Clow    minmax(initializer_list<T> t, Compare comp);  // constexpr in C++14
6094eb27b79SHoward Hinnant
6103e519524SHoward Hinnanttemplate <class InputIterator1, class InputIterator2>
6111b9a4ffdSMarshall Clow    constexpr bool     // constexpr in C++20
6123e519524SHoward Hinnant    lexicographical_compare(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, InputIterator2 last2);
6133e519524SHoward Hinnant
6143e519524SHoward Hinnanttemplate <class InputIterator1, class InputIterator2, class Compare>
6151b9a4ffdSMarshall Clow    constexpr bool     // constexpr in C++20
6163e519524SHoward Hinnant    lexicographical_compare(InputIterator1 first1, InputIterator1 last1,
6173e519524SHoward Hinnant                            InputIterator2 first2, InputIterator2 last2, Compare comp);
6183e519524SHoward Hinnant
6193e519524SHoward Hinnanttemplate <class BidirectionalIterator>
6203e519524SHoward Hinnant    bool
6213e519524SHoward Hinnant    next_permutation(BidirectionalIterator first, BidirectionalIterator last);
6223e519524SHoward Hinnant
6233e519524SHoward Hinnanttemplate <class BidirectionalIterator, class Compare>
6243e519524SHoward Hinnant    bool
6253e519524SHoward Hinnant    next_permutation(BidirectionalIterator first, BidirectionalIterator last, Compare comp);
6263e519524SHoward Hinnant
6273e519524SHoward Hinnanttemplate <class BidirectionalIterator>
6283e519524SHoward Hinnant    bool
6293e519524SHoward Hinnant    prev_permutation(BidirectionalIterator first, BidirectionalIterator last);
6303e519524SHoward Hinnant
6313e519524SHoward Hinnanttemplate <class BidirectionalIterator, class Compare>
6323e519524SHoward Hinnant    bool
6333e519524SHoward Hinnant    prev_permutation(BidirectionalIterator first, BidirectionalIterator last, Compare comp);
6343e519524SHoward Hinnant
6353e519524SHoward Hinnant}  // std
6363e519524SHoward Hinnant
6373e519524SHoward Hinnant*/
6383e519524SHoward Hinnant
6393e519524SHoward Hinnant#include <__config>
6403e519524SHoward Hinnant#include <initializer_list>
6413e519524SHoward Hinnant#include <type_traits>
6423e519524SHoward Hinnant#include <cstring>
643f07dd8d0SEric Fiselier#include <utility> // needed to provide swap_ranges.
6443e519524SHoward Hinnant#include <memory>
645d835e592SMarshall Clow#include <functional>
6463e519524SHoward Hinnant#include <iterator>
647a1d07d57SHoward Hinnant#include <cstddef>
648e02ee4f0SMarshall Clow#include <bit>
649*f56972e2SMarshall Clow#include <version>
6505d1a701dSHoward Hinnant
651c1bd9197SEric Fiselier#include <__debug>
652c1bd9197SEric Fiselier
653073458b1SHoward Hinnant#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
6543e519524SHoward Hinnant#pragma GCC system_header
655073458b1SHoward Hinnant#endif
6563e519524SHoward Hinnant
657a016efb1SEric Fiselier_LIBCPP_PUSH_MACROS
658a016efb1SEric Fiselier#include <__undef_macros>
659a016efb1SEric Fiselier
660a016efb1SEric Fiselier
6613e519524SHoward Hinnant_LIBCPP_BEGIN_NAMESPACE_STD
6623e519524SHoward Hinnant
6639d67c6d5SMarshall Clow// I'd like to replace these with _VSTD::equal_to<void>, but can't because:
6649d67c6d5SMarshall Clow//   * That only works with C++14 and later, and
6659d67c6d5SMarshall Clow//   * We haven't included <functional> here.
6663e519524SHoward Hinnanttemplate <class _T1, class _T2 = _T1>
6673e519524SHoward Hinnantstruct __equal_to
6683e519524SHoward Hinnant{
669d8098f97SMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 bool operator()(const _T1& __x, const _T1& __y) const {return __x == __y;}
670d8098f97SMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 bool operator()(const _T1& __x, const _T2& __y) const {return __x == __y;}
671d8098f97SMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 bool operator()(const _T2& __x, const _T1& __y) const {return __x == __y;}
672d8098f97SMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 bool operator()(const _T2& __x, const _T2& __y) const {return __x == __y;}
6733e519524SHoward Hinnant};
6743e519524SHoward Hinnant
6753e519524SHoward Hinnanttemplate <class _T1>
6763e519524SHoward Hinnantstruct __equal_to<_T1, _T1>
6773e519524SHoward Hinnant{
6789d67c6d5SMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
6799d67c6d5SMarshall Clow    bool operator()(const _T1& __x, const _T1& __y) const {return __x == __y;}
6803e519524SHoward Hinnant};
6813e519524SHoward Hinnant
6823e519524SHoward Hinnanttemplate <class _T1>
6833e519524SHoward Hinnantstruct __equal_to<const _T1, _T1>
6843e519524SHoward Hinnant{
6859d67c6d5SMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
6869d67c6d5SMarshall Clow    bool operator()(const _T1& __x, const _T1& __y) const {return __x == __y;}
6873e519524SHoward Hinnant};
6883e519524SHoward Hinnant
6893e519524SHoward Hinnanttemplate <class _T1>
6903e519524SHoward Hinnantstruct __equal_to<_T1, const _T1>
6913e519524SHoward Hinnant{
6929d67c6d5SMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
6939d67c6d5SMarshall Clow    bool operator()(const _T1& __x, const _T1& __y) const {return __x == __y;}
6943e519524SHoward Hinnant};
6953e519524SHoward Hinnant
6963e519524SHoward Hinnanttemplate <class _T1, class _T2 = _T1>
6973e519524SHoward Hinnantstruct __less
6983e519524SHoward Hinnant{
6999d67c6d5SMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
7009d67c6d5SMarshall Clow    bool operator()(const _T1& __x, const _T1& __y) const {return __x < __y;}
7019d67c6d5SMarshall Clow
7029d67c6d5SMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
7039d67c6d5SMarshall Clow    bool operator()(const _T1& __x, const _T2& __y) const {return __x < __y;}
7049d67c6d5SMarshall Clow
7059d67c6d5SMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
7069d67c6d5SMarshall Clow    bool operator()(const _T2& __x, const _T1& __y) const {return __x < __y;}
7079d67c6d5SMarshall Clow
7089d67c6d5SMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
7099d67c6d5SMarshall Clow    bool operator()(const _T2& __x, const _T2& __y) const {return __x < __y;}
7103e519524SHoward Hinnant};
7113e519524SHoward Hinnant
7123e519524SHoward Hinnanttemplate <class _T1>
7133e519524SHoward Hinnantstruct __less<_T1, _T1>
7143e519524SHoward Hinnant{
7159d67c6d5SMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
7169d67c6d5SMarshall Clow    bool operator()(const _T1& __x, const _T1& __y) const {return __x < __y;}
7173e519524SHoward Hinnant};
7183e519524SHoward Hinnant
7193e519524SHoward Hinnanttemplate <class _T1>
7203e519524SHoward Hinnantstruct __less<const _T1, _T1>
7213e519524SHoward Hinnant{
7229d67c6d5SMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
7239d67c6d5SMarshall Clow    bool operator()(const _T1& __x, const _T1& __y) const {return __x < __y;}
7243e519524SHoward Hinnant};
7253e519524SHoward Hinnant
7263e519524SHoward Hinnanttemplate <class _T1>
7273e519524SHoward Hinnantstruct __less<_T1, const _T1>
7283e519524SHoward Hinnant{
7299d67c6d5SMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
7309d67c6d5SMarshall Clow    bool operator()(const _T1& __x, const _T1& __y) const {return __x < __y;}
7313e519524SHoward Hinnant};
7323e519524SHoward Hinnant
7333e519524SHoward Hinnanttemplate <class _Predicate>
734a763b36fSMarshall Clowclass __invert // invert the sense of a comparison
7353e519524SHoward Hinnant{
7363e519524SHoward Hinnantprivate:
7373e519524SHoward Hinnant    _Predicate __p_;
7383e519524SHoward Hinnantpublic:
739a763b36fSMarshall Clow    _LIBCPP_INLINE_VISIBILITY __invert() {}
7403e519524SHoward Hinnant
7413e519524SHoward Hinnant    _LIBCPP_INLINE_VISIBILITY
742a763b36fSMarshall Clow    explicit __invert(_Predicate __p) : __p_(__p) {}
7433e519524SHoward Hinnant
7443e519524SHoward Hinnant    template <class _T1>
7453e519524SHoward Hinnant    _LIBCPP_INLINE_VISIBILITY
7463e519524SHoward Hinnant    bool operator()(const _T1& __x) {return !__p_(__x);}
7473e519524SHoward Hinnant
7483e519524SHoward Hinnant    template <class _T1, class _T2>
7493e519524SHoward Hinnant    _LIBCPP_INLINE_VISIBILITY
750a763b36fSMarshall Clow    bool operator()(const _T1& __x, const _T2& __y) {return __p_(__y, __x);}
7513e519524SHoward Hinnant};
7523e519524SHoward Hinnant
753145afa17SHoward Hinnant#ifdef _LIBCPP_DEBUG
7543e519524SHoward Hinnant
7553e519524SHoward Hinnanttemplate <class _Compare>
7563e519524SHoward Hinnantstruct __debug_less
7573e519524SHoward Hinnant{
7583e519524SHoward Hinnant    _Compare __comp_;
7593e519524SHoward Hinnant    __debug_less(_Compare& __c) : __comp_(__c) {}
760331d2159SEric Fiselier
7613e519524SHoward Hinnant    template <class _Tp, class _Up>
7623e519524SHoward Hinnant    bool operator()(const _Tp& __x, const _Up& __y)
7633e519524SHoward Hinnant    {
7643e519524SHoward Hinnant        bool __r = __comp_(__x, __y);
7653e519524SHoward Hinnant        if (__r)
766331d2159SEric Fiselier            __do_compare_assert(0, __y, __x);
7673e519524SHoward Hinnant        return __r;
7683e519524SHoward Hinnant    }
769331d2159SEric Fiselier
770331d2159SEric Fiselier    template <class _LHS, class _RHS>
771331d2159SEric Fiselier    inline _LIBCPP_INLINE_VISIBILITY
772331d2159SEric Fiselier    decltype((void)_VSTD::declval<_Compare&>()(
773331d2159SEric Fiselier        _VSTD::declval<_LHS const&>(), _VSTD::declval<_RHS const&>()))
774331d2159SEric Fiselier    __do_compare_assert(int, _LHS const& __l, _RHS const& __r) {
775331d2159SEric Fiselier        _LIBCPP_ASSERT(!__comp_(__l, __r),
776331d2159SEric Fiselier            "Comparator does not induce a strict weak ordering");
777331d2159SEric Fiselier    }
778331d2159SEric Fiselier
779331d2159SEric Fiselier    template <class _LHS, class _RHS>
780331d2159SEric Fiselier    inline _LIBCPP_INLINE_VISIBILITY
781331d2159SEric Fiselier    void __do_compare_assert(long, _LHS const&, _RHS const&) {}
7823e519524SHoward Hinnant};
7833e519524SHoward Hinnant
784145afa17SHoward Hinnant#endif  // _LIBCPP_DEBUG
7853e519524SHoward Hinnant
7863e519524SHoward Hinnant// all_of
7873e519524SHoward Hinnant
7883e519524SHoward Hinnanttemplate <class _InputIterator, class _Predicate>
789706ffef7SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
7903e519524SHoward Hinnantbool
7913e519524SHoward Hinnantall_of(_InputIterator __first, _InputIterator __last, _Predicate __pred)
7923e519524SHoward Hinnant{
7933e519524SHoward Hinnant    for (; __first != __last; ++__first)
7943e519524SHoward Hinnant        if (!__pred(*__first))
7953e519524SHoward Hinnant            return false;
7963e519524SHoward Hinnant    return true;
7973e519524SHoward Hinnant}
7983e519524SHoward Hinnant
7993e519524SHoward Hinnant// any_of
8003e519524SHoward Hinnant
8013e519524SHoward Hinnanttemplate <class _InputIterator, class _Predicate>
802706ffef7SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
8033e519524SHoward Hinnantbool
8043e519524SHoward Hinnantany_of(_InputIterator __first, _InputIterator __last, _Predicate __pred)
8053e519524SHoward Hinnant{
8063e519524SHoward Hinnant    for (; __first != __last; ++__first)
8073e519524SHoward Hinnant        if (__pred(*__first))
8083e519524SHoward Hinnant            return true;
8093e519524SHoward Hinnant    return false;
8103e519524SHoward Hinnant}
8113e519524SHoward Hinnant
8123e519524SHoward Hinnant// none_of
8133e519524SHoward Hinnant
8143e519524SHoward Hinnanttemplate <class _InputIterator, class _Predicate>
815706ffef7SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
8163e519524SHoward Hinnantbool
8173e519524SHoward Hinnantnone_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// for_each
8263e519524SHoward Hinnant
8273e519524SHoward Hinnanttemplate <class _InputIterator, class _Function>
8281b9a4ffdSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
8293e519524SHoward Hinnant_Function
8303e519524SHoward Hinnantfor_each(_InputIterator __first, _InputIterator __last, _Function __f)
8313e519524SHoward Hinnant{
8323e519524SHoward Hinnant    for (; __first != __last; ++__first)
8333e519524SHoward Hinnant        __f(*__first);
8341c7fe126SMarshall Clow    return __f;
8353e519524SHoward Hinnant}
8363e519524SHoward Hinnant
8371d02996dSMarshall Clow#if _LIBCPP_STD_VER > 14
838d5c65ffaSMarshall Clow// for_each_n
839d5c65ffaSMarshall Clow
840d5c65ffaSMarshall Clowtemplate <class _InputIterator, class _Size, class _Function>
8411b9a4ffdSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
842d5c65ffaSMarshall Clow_InputIterator
843d5c65ffaSMarshall Clowfor_each_n(_InputIterator __first, _Size __orig_n, _Function __f)
844d5c65ffaSMarshall Clow{
845d5c65ffaSMarshall Clow    typedef decltype(__convert_to_integral(__orig_n)) _IntegralSize;
846d5c65ffaSMarshall Clow    _IntegralSize __n = __orig_n;
847d5c65ffaSMarshall Clow    while (__n > 0)
848d5c65ffaSMarshall Clow    {
849d5c65ffaSMarshall Clow         __f(*__first);
850d5c65ffaSMarshall Clow         ++__first;
851d5c65ffaSMarshall Clow         --__n;
852d5c65ffaSMarshall Clow    }
853d5c65ffaSMarshall Clow    return __first;
854d5c65ffaSMarshall Clow}
8551d02996dSMarshall Clow#endif
856d5c65ffaSMarshall Clow
8573e519524SHoward Hinnant// find
8583e519524SHoward Hinnant
8593e519524SHoward Hinnanttemplate <class _InputIterator, class _Tp>
86049c7643cSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
8613e519524SHoward Hinnant_InputIterator
862e4383379SHoward Hinnantfind(_InputIterator __first, _InputIterator __last, const _Tp& __value_)
8633e519524SHoward Hinnant{
8643e519524SHoward Hinnant    for (; __first != __last; ++__first)
865e4383379SHoward Hinnant        if (*__first == __value_)
8663e519524SHoward Hinnant            break;
8673e519524SHoward Hinnant    return __first;
8683e519524SHoward Hinnant}
8693e519524SHoward Hinnant
8703e519524SHoward Hinnant// find_if
8713e519524SHoward Hinnant
8723e519524SHoward Hinnanttemplate <class _InputIterator, class _Predicate>
87349c7643cSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
8743e519524SHoward Hinnant_InputIterator
8753e519524SHoward Hinnantfind_if(_InputIterator __first, _InputIterator __last, _Predicate __pred)
8763e519524SHoward Hinnant{
8773e519524SHoward Hinnant    for (; __first != __last; ++__first)
8783e519524SHoward Hinnant        if (__pred(*__first))
8793e519524SHoward Hinnant            break;
8803e519524SHoward Hinnant    return __first;
8813e519524SHoward Hinnant}
8823e519524SHoward Hinnant
8833e519524SHoward Hinnant// find_if_not
8843e519524SHoward Hinnant
8853e519524SHoward Hinnanttemplate<class _InputIterator, class _Predicate>
8868694428eSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
8873e519524SHoward Hinnant_InputIterator
8883e519524SHoward Hinnantfind_if_not(_InputIterator __first, _InputIterator __last, _Predicate __pred)
8893e519524SHoward Hinnant{
8903e519524SHoward Hinnant    for (; __first != __last; ++__first)
8913e519524SHoward Hinnant        if (!__pred(*__first))
8923e519524SHoward Hinnant            break;
8933e519524SHoward Hinnant    return __first;
8943e519524SHoward Hinnant}
8953e519524SHoward Hinnant
8963e519524SHoward Hinnant// find_end
8973e519524SHoward Hinnant
8983e519524SHoward Hinnanttemplate <class _BinaryPredicate, class _ForwardIterator1, class _ForwardIterator2>
8998694428eSMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator1
9003e519524SHoward Hinnant__find_end(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
9013e519524SHoward Hinnant           _ForwardIterator2 __first2, _ForwardIterator2 __last2, _BinaryPredicate __pred,
9023e519524SHoward Hinnant           forward_iterator_tag, forward_iterator_tag)
9033e519524SHoward Hinnant{
9043e519524SHoward Hinnant    // modeled after search algorithm
9053e519524SHoward Hinnant    _ForwardIterator1 __r = __last1;  // __last1 is the "default" answer
9063e519524SHoward Hinnant    if (__first2 == __last2)
9073e519524SHoward Hinnant        return __r;
9083e519524SHoward Hinnant    while (true)
9093e519524SHoward Hinnant    {
9103e519524SHoward Hinnant        while (true)
9113e519524SHoward Hinnant        {
9123e519524SHoward Hinnant            if (__first1 == __last1)         // if source exhausted return last correct answer
9133e519524SHoward Hinnant                return __r;                  //    (or __last1 if never found)
9143e519524SHoward Hinnant            if (__pred(*__first1, *__first2))
9153e519524SHoward Hinnant                break;
9163e519524SHoward Hinnant            ++__first1;
9173e519524SHoward Hinnant        }
9183e519524SHoward Hinnant        // *__first1 matches *__first2, now match elements after here
9193e519524SHoward Hinnant        _ForwardIterator1 __m1 = __first1;
9203e519524SHoward Hinnant        _ForwardIterator2 __m2 = __first2;
9213e519524SHoward Hinnant        while (true)
9223e519524SHoward Hinnant        {
9233e519524SHoward Hinnant            if (++__m2 == __last2)
9243e519524SHoward Hinnant            {                         // Pattern exhaused, record answer and search for another one
9253e519524SHoward Hinnant                __r = __first1;
9263e519524SHoward Hinnant                ++__first1;
9273e519524SHoward Hinnant                break;
9283e519524SHoward Hinnant            }
9293e519524SHoward Hinnant            if (++__m1 == __last1)     // Source exhausted, return last answer
9303e519524SHoward Hinnant                return __r;
9313e519524SHoward Hinnant            if (!__pred(*__m1, *__m2))  // mismatch, restart with a new __first
9323e519524SHoward Hinnant            {
9333e519524SHoward Hinnant                ++__first1;
9343e519524SHoward Hinnant                break;
9353e519524SHoward Hinnant            }  // else there is a match, check next elements
9363e519524SHoward Hinnant        }
9373e519524SHoward Hinnant    }
9383e519524SHoward Hinnant}
9393e519524SHoward Hinnant
9403e519524SHoward Hinnanttemplate <class _BinaryPredicate, class _BidirectionalIterator1, class _BidirectionalIterator2>
9418694428eSMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 _BidirectionalIterator1
9423e519524SHoward Hinnant__find_end(_BidirectionalIterator1 __first1, _BidirectionalIterator1 __last1,
9433e519524SHoward Hinnant           _BidirectionalIterator2 __first2, _BidirectionalIterator2 __last2, _BinaryPredicate __pred,
9443e519524SHoward Hinnant           bidirectional_iterator_tag, bidirectional_iterator_tag)
9453e519524SHoward Hinnant{
9463e519524SHoward Hinnant    // modeled after search algorithm (in reverse)
9473e519524SHoward Hinnant    if (__first2 == __last2)
9483e519524SHoward Hinnant        return __last1;  // Everything matches an empty sequence
9493e519524SHoward Hinnant    _BidirectionalIterator1 __l1 = __last1;
9503e519524SHoward Hinnant    _BidirectionalIterator2 __l2 = __last2;
9513e519524SHoward Hinnant    --__l2;
9523e519524SHoward Hinnant    while (true)
9533e519524SHoward Hinnant    {
9543e519524SHoward Hinnant        // Find last element in sequence 1 that matchs *(__last2-1), with a mininum of loop checks
9553e519524SHoward Hinnant        while (true)
9563e519524SHoward Hinnant        {
9573e519524SHoward Hinnant            if (__first1 == __l1)  // return __last1 if no element matches *__first2
9583e519524SHoward Hinnant                return __last1;
9593e519524SHoward Hinnant            if (__pred(*--__l1, *__l2))
9603e519524SHoward Hinnant                break;
9613e519524SHoward Hinnant        }
9623e519524SHoward Hinnant        // *__l1 matches *__l2, now match elements before here
9633e519524SHoward Hinnant        _BidirectionalIterator1 __m1 = __l1;
9643e519524SHoward Hinnant        _BidirectionalIterator2 __m2 = __l2;
9653e519524SHoward Hinnant        while (true)
9663e519524SHoward Hinnant        {
9673e519524SHoward Hinnant            if (__m2 == __first2)  // If pattern exhausted, __m1 is the answer (works for 1 element pattern)
9683e519524SHoward Hinnant                return __m1;
9693e519524SHoward Hinnant            if (__m1 == __first1)  // Otherwise if source exhaused, pattern not found
9703e519524SHoward Hinnant                return __last1;
9713e519524SHoward Hinnant            if (!__pred(*--__m1, *--__m2))  // if there is a mismatch, restart with a new __l1
9723e519524SHoward Hinnant            {
9733e519524SHoward Hinnant                break;
9743e519524SHoward Hinnant            }  // else there is a match, check next elements
9753e519524SHoward Hinnant        }
9763e519524SHoward Hinnant    }
9773e519524SHoward Hinnant}
9783e519524SHoward Hinnant
9793e519524SHoward Hinnanttemplate <class _BinaryPredicate, class _RandomAccessIterator1, class _RandomAccessIterator2>
9809b0af34dSMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX11 _RandomAccessIterator1
9813e519524SHoward Hinnant__find_end(_RandomAccessIterator1 __first1, _RandomAccessIterator1 __last1,
9823e519524SHoward Hinnant           _RandomAccessIterator2 __first2, _RandomAccessIterator2 __last2, _BinaryPredicate __pred,
9833e519524SHoward Hinnant           random_access_iterator_tag, random_access_iterator_tag)
9843e519524SHoward Hinnant{
9853e519524SHoward Hinnant    // Take advantage of knowing source and pattern lengths.  Stop short when source is smaller than pattern
9863e519524SHoward Hinnant    typename iterator_traits<_RandomAccessIterator2>::difference_type __len2 = __last2 - __first2;
9873e519524SHoward Hinnant    if (__len2 == 0)
9883e519524SHoward Hinnant        return __last1;
9893e519524SHoward Hinnant    typename iterator_traits<_RandomAccessIterator1>::difference_type __len1 = __last1 - __first1;
9903e519524SHoward Hinnant    if (__len1 < __len2)
9913e519524SHoward Hinnant        return __last1;
9923e519524SHoward Hinnant    const _RandomAccessIterator1 __s = __first1 + (__len2 - 1);  // End of pattern match can't go before here
9933e519524SHoward Hinnant    _RandomAccessIterator1 __l1 = __last1;
9943e519524SHoward Hinnant    _RandomAccessIterator2 __l2 = __last2;
9953e519524SHoward Hinnant    --__l2;
9963e519524SHoward Hinnant    while (true)
9973e519524SHoward Hinnant    {
9983e519524SHoward Hinnant        while (true)
9993e519524SHoward Hinnant        {
10003e519524SHoward Hinnant            if (__s == __l1)
10013e519524SHoward Hinnant                return __last1;
10023e519524SHoward Hinnant            if (__pred(*--__l1, *__l2))
10033e519524SHoward Hinnant                break;
10043e519524SHoward Hinnant        }
10053e519524SHoward Hinnant        _RandomAccessIterator1 __m1 = __l1;
10063e519524SHoward Hinnant        _RandomAccessIterator2 __m2 = __l2;
10073e519524SHoward Hinnant        while (true)
10083e519524SHoward Hinnant        {
10093e519524SHoward Hinnant            if (__m2 == __first2)
10103e519524SHoward Hinnant                return __m1;
10113e519524SHoward Hinnant                                 // no need to check range on __m1 because __s guarantees we have enough source
10123e519524SHoward Hinnant            if (!__pred(*--__m1, *--__m2))
10133e519524SHoward Hinnant            {
10143e519524SHoward Hinnant                break;
10153e519524SHoward Hinnant            }
10163e519524SHoward Hinnant        }
10173e519524SHoward Hinnant    }
10183e519524SHoward Hinnant}
10193e519524SHoward Hinnant
10203e519524SHoward Hinnanttemplate <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
10218694428eSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
10223e519524SHoward Hinnant_ForwardIterator1
10233e519524SHoward Hinnantfind_end(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
10243e519524SHoward Hinnant         _ForwardIterator2 __first2, _ForwardIterator2 __last2, _BinaryPredicate __pred)
10253e519524SHoward Hinnant{
1026ce48a113SHoward Hinnant    return _VSTD::__find_end<typename add_lvalue_reference<_BinaryPredicate>::type>
10273e519524SHoward Hinnant                         (__first1, __last1, __first2, __last2, __pred,
10283e519524SHoward Hinnant                          typename iterator_traits<_ForwardIterator1>::iterator_category(),
10293e519524SHoward Hinnant                          typename iterator_traits<_ForwardIterator2>::iterator_category());
10303e519524SHoward Hinnant}
10313e519524SHoward Hinnant
10323e519524SHoward Hinnanttemplate <class _ForwardIterator1, class _ForwardIterator2>
10338694428eSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
10343e519524SHoward Hinnant_ForwardIterator1
10353e519524SHoward Hinnantfind_end(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
10363e519524SHoward Hinnant         _ForwardIterator2 __first2, _ForwardIterator2 __last2)
10373e519524SHoward Hinnant{
10383e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator1>::value_type __v1;
10393e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator2>::value_type __v2;
1040ce48a113SHoward Hinnant    return _VSTD::find_end(__first1, __last1, __first2, __last2, __equal_to<__v1, __v2>());
10413e519524SHoward Hinnant}
10423e519524SHoward Hinnant
10433e519524SHoward Hinnant// find_first_of
10443e519524SHoward Hinnant
10453e519524SHoward Hinnanttemplate <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
10469b0af34dSMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX11 _ForwardIterator1
10479b0af34dSMarshall Clow__find_first_of_ce(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
10483e519524SHoward Hinnant              _ForwardIterator2 __first2, _ForwardIterator2 __last2, _BinaryPredicate __pred)
10493e519524SHoward Hinnant{
10503e519524SHoward Hinnant    for (; __first1 != __last1; ++__first1)
10513e519524SHoward Hinnant        for (_ForwardIterator2 __j = __first2; __j != __last2; ++__j)
10523e519524SHoward Hinnant            if (__pred(*__first1, *__j))
10533e519524SHoward Hinnant                return __first1;
10543e519524SHoward Hinnant    return __last1;
10553e519524SHoward Hinnant}
10563e519524SHoward Hinnant
10579b0af34dSMarshall Clow
10589b0af34dSMarshall Clowtemplate <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
10598694428eSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY  _LIBCPP_CONSTEXPR_AFTER_CXX17
10609b0af34dSMarshall Clow_ForwardIterator1
10619b0af34dSMarshall Clowfind_first_of(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
10629b0af34dSMarshall Clow              _ForwardIterator2 __first2, _ForwardIterator2 __last2, _BinaryPredicate __pred)
10639b0af34dSMarshall Clow{
10649b0af34dSMarshall Clow    return _VSTD::__find_first_of_ce(__first1, __last1, __first2, __last2, __pred);
10659b0af34dSMarshall Clow}
10669b0af34dSMarshall Clow
10673e519524SHoward Hinnanttemplate <class _ForwardIterator1, class _ForwardIterator2>
10688694428eSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY  _LIBCPP_CONSTEXPR_AFTER_CXX17
10693e519524SHoward Hinnant_ForwardIterator1
10703e519524SHoward Hinnantfind_first_of(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
10713e519524SHoward Hinnant              _ForwardIterator2 __first2, _ForwardIterator2 __last2)
10723e519524SHoward Hinnant{
10733e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator1>::value_type __v1;
10743e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator2>::value_type __v2;
10759b0af34dSMarshall Clow    return _VSTD::__find_first_of_ce(__first1, __last1, __first2, __last2, __equal_to<__v1, __v2>());
10763e519524SHoward Hinnant}
10773e519524SHoward Hinnant
10783e519524SHoward Hinnant// adjacent_find
10793e519524SHoward Hinnant
10803e519524SHoward Hinnanttemplate <class _ForwardIterator, class _BinaryPredicate>
10818694428eSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
10823e519524SHoward Hinnant_ForwardIterator
10833e519524SHoward Hinnantadjacent_find(_ForwardIterator __first, _ForwardIterator __last, _BinaryPredicate __pred)
10843e519524SHoward Hinnant{
10853e519524SHoward Hinnant    if (__first != __last)
10863e519524SHoward Hinnant    {
10873e519524SHoward Hinnant        _ForwardIterator __i = __first;
10883e519524SHoward Hinnant        while (++__i != __last)
10893e519524SHoward Hinnant        {
10903e519524SHoward Hinnant            if (__pred(*__first, *__i))
10913e519524SHoward Hinnant                return __first;
10923e519524SHoward Hinnant            __first = __i;
10933e519524SHoward Hinnant        }
10943e519524SHoward Hinnant    }
10953e519524SHoward Hinnant    return __last;
10963e519524SHoward Hinnant}
10973e519524SHoward Hinnant
10983e519524SHoward Hinnanttemplate <class _ForwardIterator>
10998694428eSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
11003e519524SHoward Hinnant_ForwardIterator
11013e519524SHoward Hinnantadjacent_find(_ForwardIterator __first, _ForwardIterator __last)
11023e519524SHoward Hinnant{
11033e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator>::value_type __v;
1104ce48a113SHoward Hinnant    return _VSTD::adjacent_find(__first, __last, __equal_to<__v>());
11053e519524SHoward Hinnant}
11063e519524SHoward Hinnant
11073e519524SHoward Hinnant// count
11083e519524SHoward Hinnant
11093e519524SHoward Hinnanttemplate <class _InputIterator, class _Tp>
1110056f15e3SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
11113e519524SHoward Hinnanttypename iterator_traits<_InputIterator>::difference_type
1112e4383379SHoward Hinnantcount(_InputIterator __first, _InputIterator __last, const _Tp& __value_)
11133e519524SHoward Hinnant{
11143e519524SHoward Hinnant    typename iterator_traits<_InputIterator>::difference_type __r(0);
11153e519524SHoward Hinnant    for (; __first != __last; ++__first)
1116e4383379SHoward Hinnant        if (*__first == __value_)
11173e519524SHoward Hinnant            ++__r;
11183e519524SHoward Hinnant    return __r;
11193e519524SHoward Hinnant}
11203e519524SHoward Hinnant
11213e519524SHoward Hinnant// count_if
11223e519524SHoward Hinnant
11233e519524SHoward Hinnanttemplate <class _InputIterator, class _Predicate>
1124056f15e3SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
11253e519524SHoward Hinnanttypename iterator_traits<_InputIterator>::difference_type
11263e519524SHoward Hinnantcount_if(_InputIterator __first, _InputIterator __last, _Predicate __pred)
11273e519524SHoward Hinnant{
11283e519524SHoward Hinnant    typename iterator_traits<_InputIterator>::difference_type __r(0);
11293e519524SHoward Hinnant    for (; __first != __last; ++__first)
11303e519524SHoward Hinnant        if (__pred(*__first))
11313e519524SHoward Hinnant            ++__r;
11323e519524SHoward Hinnant    return __r;
11333e519524SHoward Hinnant}
11343e519524SHoward Hinnant
11353e519524SHoward Hinnant// mismatch
11363e519524SHoward Hinnant
11373e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
11386538e28dSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
11393e519524SHoward Hinnantpair<_InputIterator1, _InputIterator2>
11403e519524SHoward Hinnantmismatch(_InputIterator1 __first1, _InputIterator1 __last1,
11413e519524SHoward Hinnant         _InputIterator2 __first2, _BinaryPredicate __pred)
11423e519524SHoward Hinnant{
1143bd7c7b55SMarshall Clow    for (; __first1 != __last1; ++__first1, (void) ++__first2)
11443e519524SHoward Hinnant        if (!__pred(*__first1, *__first2))
11453e519524SHoward Hinnant            break;
11463e519524SHoward Hinnant    return pair<_InputIterator1, _InputIterator2>(__first1, __first2);
11473e519524SHoward Hinnant}
11483e519524SHoward Hinnant
11493e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2>
11506538e28dSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
11513e519524SHoward Hinnantpair<_InputIterator1, _InputIterator2>
11523e519524SHoward Hinnantmismatch(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2)
11533e519524SHoward Hinnant{
11543e519524SHoward Hinnant    typedef typename iterator_traits<_InputIterator1>::value_type __v1;
11553e519524SHoward Hinnant    typedef typename iterator_traits<_InputIterator2>::value_type __v2;
1156ce48a113SHoward Hinnant    return _VSTD::mismatch(__first1, __last1, __first2, __equal_to<__v1, __v2>());
11573e519524SHoward Hinnant}
11583e519524SHoward Hinnant
11590b0bbd2fSMarshall Clow#if _LIBCPP_STD_VER > 11
11600b0bbd2fSMarshall Clowtemplate <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
11616538e28dSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
11620b0bbd2fSMarshall Clowpair<_InputIterator1, _InputIterator2>
11630b0bbd2fSMarshall Clowmismatch(_InputIterator1 __first1, _InputIterator1 __last1,
11640b0bbd2fSMarshall Clow         _InputIterator2 __first2, _InputIterator2 __last2,
11650b0bbd2fSMarshall Clow         _BinaryPredicate __pred)
11660b0bbd2fSMarshall Clow{
1167bd7c7b55SMarshall Clow    for (; __first1 != __last1 && __first2 != __last2; ++__first1, (void) ++__first2)
11680b0bbd2fSMarshall Clow        if (!__pred(*__first1, *__first2))
11690b0bbd2fSMarshall Clow            break;
11700b0bbd2fSMarshall Clow    return pair<_InputIterator1, _InputIterator2>(__first1, __first2);
11710b0bbd2fSMarshall Clow}
11720b0bbd2fSMarshall Clow
11730b0bbd2fSMarshall Clowtemplate <class _InputIterator1, class _InputIterator2>
11746538e28dSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
11750b0bbd2fSMarshall Clowpair<_InputIterator1, _InputIterator2>
11760b0bbd2fSMarshall Clowmismatch(_InputIterator1 __first1, _InputIterator1 __last1,
11770b0bbd2fSMarshall Clow         _InputIterator2 __first2, _InputIterator2 __last2)
11780b0bbd2fSMarshall Clow{
11790b0bbd2fSMarshall Clow    typedef typename iterator_traits<_InputIterator1>::value_type __v1;
11800b0bbd2fSMarshall Clow    typedef typename iterator_traits<_InputIterator2>::value_type __v2;
11810b0bbd2fSMarshall Clow    return _VSTD::mismatch(__first1, __last1, __first2, __last2, __equal_to<__v1, __v2>());
11820b0bbd2fSMarshall Clow}
11830b0bbd2fSMarshall Clow#endif
11840b0bbd2fSMarshall Clow
11853e519524SHoward Hinnant// equal
11863e519524SHoward Hinnant
11873e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
11886538e28dSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
11893e519524SHoward Hinnantbool
11903e519524SHoward Hinnantequal(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _BinaryPredicate __pred)
11913e519524SHoward Hinnant{
1192910285b2SEric Fiselier    for (; __first1 != __last1; ++__first1, (void) ++__first2)
11933e519524SHoward Hinnant        if (!__pred(*__first1, *__first2))
11943e519524SHoward Hinnant            return false;
11953e519524SHoward Hinnant    return true;
11963e519524SHoward Hinnant}
11973e519524SHoward Hinnant
11983e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2>
11996538e28dSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
12003e519524SHoward Hinnantbool
12013e519524SHoward Hinnantequal(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2)
12023e519524SHoward Hinnant{
12033e519524SHoward Hinnant    typedef typename iterator_traits<_InputIterator1>::value_type __v1;
12043e519524SHoward Hinnant    typedef typename iterator_traits<_InputIterator2>::value_type __v2;
1205ce48a113SHoward Hinnant    return _VSTD::equal(__first1, __last1, __first2, __equal_to<__v1, __v2>());
12063e519524SHoward Hinnant}
12073e519524SHoward Hinnant
12080b0bbd2fSMarshall Clow#if _LIBCPP_STD_VER > 11
12090b0bbd2fSMarshall Clowtemplate <class _BinaryPredicate, class _InputIterator1, class _InputIterator2>
12106538e28dSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
12110b0bbd2fSMarshall Clowbool
12120b0bbd2fSMarshall Clow__equal(_InputIterator1 __first1, _InputIterator1 __last1,
12130b0bbd2fSMarshall Clow        _InputIterator2 __first2, _InputIterator2 __last2, _BinaryPredicate __pred,
12140b0bbd2fSMarshall Clow        input_iterator_tag, input_iterator_tag )
12150b0bbd2fSMarshall Clow{
1216910285b2SEric Fiselier    for (; __first1 != __last1 && __first2 != __last2; ++__first1, (void) ++__first2)
12170b0bbd2fSMarshall Clow        if (!__pred(*__first1, *__first2))
12180b0bbd2fSMarshall Clow            return false;
12190b0bbd2fSMarshall Clow    return __first1 == __last1 && __first2 == __last2;
12200b0bbd2fSMarshall Clow}
12210b0bbd2fSMarshall Clow
12220b0bbd2fSMarshall Clowtemplate <class _BinaryPredicate, class _RandomAccessIterator1, class _RandomAccessIterator2>
12236538e28dSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
12240b0bbd2fSMarshall Clowbool
12250b0bbd2fSMarshall Clow__equal(_RandomAccessIterator1 __first1, _RandomAccessIterator1 __last1,
12260b0bbd2fSMarshall Clow        _RandomAccessIterator2 __first2, _RandomAccessIterator2 __last2, _BinaryPredicate __pred,
12270b0bbd2fSMarshall Clow      random_access_iterator_tag, random_access_iterator_tag )
12280b0bbd2fSMarshall Clow{
12290b0bbd2fSMarshall Clow    if ( _VSTD::distance(__first1, __last1) != _VSTD::distance(__first2, __last2))
12300b0bbd2fSMarshall Clow        return false;
12310b0bbd2fSMarshall Clow    return _VSTD::equal<_RandomAccessIterator1, _RandomAccessIterator2,
12320b0bbd2fSMarshall Clow                        typename add_lvalue_reference<_BinaryPredicate>::type>
12330b0bbd2fSMarshall Clow                       (__first1, __last1, __first2, __pred );
12340b0bbd2fSMarshall Clow}
12350b0bbd2fSMarshall Clow
12360b0bbd2fSMarshall Clowtemplate <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
12376538e28dSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
12380b0bbd2fSMarshall Clowbool
12390b0bbd2fSMarshall Clowequal(_InputIterator1 __first1, _InputIterator1 __last1,
12400b0bbd2fSMarshall Clow      _InputIterator2 __first2, _InputIterator2 __last2, _BinaryPredicate __pred )
12410b0bbd2fSMarshall Clow{
12420b0bbd2fSMarshall Clow    return _VSTD::__equal<typename add_lvalue_reference<_BinaryPredicate>::type>
12430b0bbd2fSMarshall Clow       (__first1, __last1, __first2, __last2, __pred,
12440b0bbd2fSMarshall Clow        typename iterator_traits<_InputIterator1>::iterator_category(),
12450b0bbd2fSMarshall Clow        typename iterator_traits<_InputIterator2>::iterator_category());
12460b0bbd2fSMarshall Clow}
12470b0bbd2fSMarshall Clow
12480b0bbd2fSMarshall Clowtemplate <class _InputIterator1, class _InputIterator2>
12496538e28dSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
12500b0bbd2fSMarshall Clowbool
12510b0bbd2fSMarshall Clowequal(_InputIterator1 __first1, _InputIterator1 __last1,
12520b0bbd2fSMarshall Clow      _InputIterator2 __first2, _InputIterator2 __last2)
12530b0bbd2fSMarshall Clow{
12540b0bbd2fSMarshall Clow    typedef typename iterator_traits<_InputIterator1>::value_type __v1;
12550b0bbd2fSMarshall Clow    typedef typename iterator_traits<_InputIterator2>::value_type __v2;
12560b0bbd2fSMarshall Clow    return _VSTD::__equal(__first1, __last1, __first2, __last2, __equal_to<__v1, __v2>(),
12570b0bbd2fSMarshall Clow        typename iterator_traits<_InputIterator1>::iterator_category(),
12580b0bbd2fSMarshall Clow        typename iterator_traits<_InputIterator2>::iterator_category());
12590b0bbd2fSMarshall Clow}
12600b0bbd2fSMarshall Clow#endif
12610b0bbd2fSMarshall Clow
12623e519524SHoward Hinnant// is_permutation
12633e519524SHoward Hinnant
12643e519524SHoward Hinnanttemplate<class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
126549c7643cSMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
12663e519524SHoward Hinnantis_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
12673e519524SHoward Hinnant               _ForwardIterator2 __first2, _BinaryPredicate __pred)
12683e519524SHoward Hinnant{
126949c7643cSMarshall Clow//  shorten sequences as much as possible by lopping of any equal prefix
1270910285b2SEric Fiselier    for (; __first1 != __last1; ++__first1, (void) ++__first2)
12713e519524SHoward Hinnant        if (!__pred(*__first1, *__first2))
127249c7643cSMarshall Clow            break;
127349c7643cSMarshall Clow    if (__first1 == __last1)
12743e519524SHoward Hinnant        return true;
127549c7643cSMarshall Clow
12763e519524SHoward Hinnant//  __first1 != __last1 && *__first1 != *__first2
12773e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator1>::difference_type _D1;
1278ce48a113SHoward Hinnant    _D1 __l1 = _VSTD::distance(__first1, __last1);
12793e519524SHoward Hinnant    if (__l1 == _D1(1))
12803e519524SHoward Hinnant        return false;
1281ce48a113SHoward Hinnant    _ForwardIterator2 __last2 = _VSTD::next(__first2, __l1);
12823e519524SHoward Hinnant    // For each element in [f1, l1) see if there are the same number of
12833e519524SHoward Hinnant    //    equal elements in [f2, l2)
12843e519524SHoward Hinnant    for (_ForwardIterator1 __i = __first1; __i != __last1; ++__i)
12853e519524SHoward Hinnant    {
12863e519524SHoward Hinnant    //  Have we already counted the number of *__i in [f1, l1)?
1287939b1623SPeter Collingbourne        _ForwardIterator1 __match = __first1;
1288939b1623SPeter Collingbourne        for (; __match != __i; ++__match)
1289939b1623SPeter Collingbourne            if (__pred(*__match, *__i))
1290939b1623SPeter Collingbourne                break;
1291939b1623SPeter Collingbourne        if (__match == __i) {
12923e519524SHoward Hinnant            // Count number of *__i in [f2, l2)
12933e519524SHoward Hinnant            _D1 __c2 = 0;
12943e519524SHoward Hinnant            for (_ForwardIterator2 __j = __first2; __j != __last2; ++__j)
12953e519524SHoward Hinnant                if (__pred(*__i, *__j))
12963e519524SHoward Hinnant                    ++__c2;
12973e519524SHoward Hinnant            if (__c2 == 0)
12983e519524SHoward Hinnant                return false;
12993e519524SHoward Hinnant            // Count number of *__i in [__i, l1) (we can start with 1)
13003e519524SHoward Hinnant            _D1 __c1 = 1;
1301ce48a113SHoward Hinnant            for (_ForwardIterator1 __j = _VSTD::next(__i); __j != __last1; ++__j)
13023e519524SHoward Hinnant                if (__pred(*__i, *__j))
13033e519524SHoward Hinnant                    ++__c1;
13043e519524SHoward Hinnant            if (__c1 != __c2)
13053e519524SHoward Hinnant                return false;
13063e519524SHoward Hinnant        }
13073e519524SHoward Hinnant    }
13083e519524SHoward Hinnant    return true;
13093e519524SHoward Hinnant}
13103e519524SHoward Hinnant
13113e519524SHoward Hinnanttemplate<class _ForwardIterator1, class _ForwardIterator2>
131249c7643cSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
13133e519524SHoward Hinnantbool
13143e519524SHoward Hinnantis_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
13153e519524SHoward Hinnant               _ForwardIterator2 __first2)
13163e519524SHoward Hinnant{
13173e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator1>::value_type __v1;
13183e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator2>::value_type __v2;
1319ce48a113SHoward Hinnant    return _VSTD::is_permutation(__first1, __last1, __first2, __equal_to<__v1, __v2>());
13203e519524SHoward Hinnant}
13213e519524SHoward Hinnant
13220b0bbd2fSMarshall Clow#if _LIBCPP_STD_VER > 11
13230b0bbd2fSMarshall Clowtemplate<class _BinaryPredicate, class _ForwardIterator1, class _ForwardIterator2>
132449c7643cSMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
13250b0bbd2fSMarshall Clow__is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
13260b0bbd2fSMarshall Clow                 _ForwardIterator2 __first2, _ForwardIterator2 __last2,
13270b0bbd2fSMarshall Clow                 _BinaryPredicate __pred,
13280b0bbd2fSMarshall Clow                 forward_iterator_tag, forward_iterator_tag )
13290b0bbd2fSMarshall Clow{
133049c7643cSMarshall Clow//  shorten sequences as much as possible by lopping of any equal prefix
1331847ee131SEric Fiselier    for (; __first1 != __last1 && __first2 != __last2; ++__first1, (void) ++__first2)
13320b0bbd2fSMarshall Clow        if (!__pred(*__first1, *__first2))
133349c7643cSMarshall Clow            break;
133449c7643cSMarshall Clow    if (__first1 == __last1)
133549c7643cSMarshall Clow        return __first2 == __last2;
133649c7643cSMarshall Clow    else if (__first2 == __last2)
133749c7643cSMarshall Clow        return false;
133849c7643cSMarshall Clow
13390b0bbd2fSMarshall Clow    typedef typename iterator_traits<_ForwardIterator1>::difference_type _D1;
13400b0bbd2fSMarshall Clow    _D1 __l1 = _VSTD::distance(__first1, __last1);
13410b0bbd2fSMarshall Clow
13420b0bbd2fSMarshall Clow    typedef typename iterator_traits<_ForwardIterator2>::difference_type _D2;
1343fce85ba4SMarshall Clow    _D2 __l2 = _VSTD::distance(__first2, __last2);
13440b0bbd2fSMarshall Clow    if (__l1 != __l2)
13450b0bbd2fSMarshall Clow        return false;
13460b0bbd2fSMarshall Clow
13470b0bbd2fSMarshall Clow    // For each element in [f1, l1) see if there are the same number of
13480b0bbd2fSMarshall Clow    //    equal elements in [f2, l2)
13490b0bbd2fSMarshall Clow    for (_ForwardIterator1 __i = __first1; __i != __last1; ++__i)
13500b0bbd2fSMarshall Clow    {
13510b0bbd2fSMarshall Clow    //  Have we already counted the number of *__i in [f1, l1)?
1352939b1623SPeter Collingbourne        _ForwardIterator1 __match = __first1;
1353939b1623SPeter Collingbourne        for (; __match != __i; ++__match)
1354939b1623SPeter Collingbourne            if (__pred(*__match, *__i))
1355939b1623SPeter Collingbourne                break;
1356939b1623SPeter Collingbourne        if (__match == __i) {
13570b0bbd2fSMarshall Clow            // Count number of *__i in [f2, l2)
13580b0bbd2fSMarshall Clow            _D1 __c2 = 0;
13590b0bbd2fSMarshall Clow            for (_ForwardIterator2 __j = __first2; __j != __last2; ++__j)
13600b0bbd2fSMarshall Clow                if (__pred(*__i, *__j))
13610b0bbd2fSMarshall Clow                    ++__c2;
13620b0bbd2fSMarshall Clow            if (__c2 == 0)
13630b0bbd2fSMarshall Clow                return false;
13640b0bbd2fSMarshall Clow            // Count number of *__i in [__i, l1) (we can start with 1)
13650b0bbd2fSMarshall Clow            _D1 __c1 = 1;
13660b0bbd2fSMarshall Clow            for (_ForwardIterator1 __j = _VSTD::next(__i); __j != __last1; ++__j)
13670b0bbd2fSMarshall Clow                if (__pred(*__i, *__j))
13680b0bbd2fSMarshall Clow                    ++__c1;
13690b0bbd2fSMarshall Clow            if (__c1 != __c2)
13700b0bbd2fSMarshall Clow                return false;
13710b0bbd2fSMarshall Clow        }
13720b0bbd2fSMarshall Clow    }
13730b0bbd2fSMarshall Clow    return true;
13740b0bbd2fSMarshall Clow}
13750b0bbd2fSMarshall Clow
13760b0bbd2fSMarshall Clowtemplate<class _BinaryPredicate, class _RandomAccessIterator1, class _RandomAccessIterator2>
137749c7643cSMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
13780b0bbd2fSMarshall Clow__is_permutation(_RandomAccessIterator1 __first1, _RandomAccessIterator2 __last1,
13790b0bbd2fSMarshall Clow               _RandomAccessIterator1 __first2, _RandomAccessIterator2 __last2,
13800b0bbd2fSMarshall Clow               _BinaryPredicate __pred,
13810b0bbd2fSMarshall Clow               random_access_iterator_tag, random_access_iterator_tag )
13820b0bbd2fSMarshall Clow{
13830b0bbd2fSMarshall Clow    if ( _VSTD::distance(__first1, __last1) != _VSTD::distance(__first2, __last2))
13840b0bbd2fSMarshall Clow        return false;
13850b0bbd2fSMarshall Clow    return _VSTD::is_permutation<_RandomAccessIterator1, _RandomAccessIterator2,
13860b0bbd2fSMarshall Clow                                 typename add_lvalue_reference<_BinaryPredicate>::type>
13870b0bbd2fSMarshall Clow                                (__first1, __last1, __first2, __pred );
13880b0bbd2fSMarshall Clow}
13890b0bbd2fSMarshall Clow
13900b0bbd2fSMarshall Clowtemplate<class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
139149c7643cSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
13920b0bbd2fSMarshall Clowbool
13930b0bbd2fSMarshall Clowis_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
13940b0bbd2fSMarshall Clow               _ForwardIterator2 __first2, _ForwardIterator2 __last2,
13950b0bbd2fSMarshall Clow               _BinaryPredicate __pred )
13960b0bbd2fSMarshall Clow{
13970b0bbd2fSMarshall Clow    return _VSTD::__is_permutation<typename add_lvalue_reference<_BinaryPredicate>::type>
13980b0bbd2fSMarshall Clow       (__first1, __last1, __first2, __last2, __pred,
13990b0bbd2fSMarshall Clow        typename iterator_traits<_ForwardIterator1>::iterator_category(),
14000b0bbd2fSMarshall Clow        typename iterator_traits<_ForwardIterator2>::iterator_category());
14010b0bbd2fSMarshall Clow}
14020b0bbd2fSMarshall Clow
14030b0bbd2fSMarshall Clowtemplate<class _ForwardIterator1, class _ForwardIterator2>
140449c7643cSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
14050b0bbd2fSMarshall Clowbool
14060b0bbd2fSMarshall Clowis_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
14070b0bbd2fSMarshall Clow               _ForwardIterator2 __first2, _ForwardIterator2 __last2)
14080b0bbd2fSMarshall Clow{
14090b0bbd2fSMarshall Clow    typedef typename iterator_traits<_ForwardIterator1>::value_type __v1;
14100b0bbd2fSMarshall Clow    typedef typename iterator_traits<_ForwardIterator2>::value_type __v2;
14110b0bbd2fSMarshall Clow    return _VSTD::__is_permutation(__first1, __last1, __first2, __last2,
14120b0bbd2fSMarshall Clow        __equal_to<__v1, __v2>(),
14130b0bbd2fSMarshall Clow        typename iterator_traits<_ForwardIterator1>::iterator_category(),
14140b0bbd2fSMarshall Clow        typename iterator_traits<_ForwardIterator2>::iterator_category());
14150b0bbd2fSMarshall Clow}
14160b0bbd2fSMarshall Clow#endif
14170b0bbd2fSMarshall Clow
14183e519524SHoward Hinnant// search
1419d835e592SMarshall Clow// __search is in <functional>
14203e519524SHoward Hinnant
14213e519524SHoward Hinnanttemplate <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
142212f0a779SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
14233e519524SHoward Hinnant_ForwardIterator1
14243e519524SHoward Hinnantsearch(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
14253e519524SHoward Hinnant       _ForwardIterator2 __first2, _ForwardIterator2 __last2, _BinaryPredicate __pred)
14263e519524SHoward Hinnant{
1427ce48a113SHoward Hinnant    return _VSTD::__search<typename add_lvalue_reference<_BinaryPredicate>::type>
14283e519524SHoward Hinnant                         (__first1, __last1, __first2, __last2, __pred,
142928cc4ddeSMarshall Clow                          typename iterator_traits<_ForwardIterator1>::iterator_category(),
143028cc4ddeSMarshall Clow                          typename iterator_traits<_ForwardIterator2>::iterator_category())
143128cc4ddeSMarshall Clow            .first;
14323e519524SHoward Hinnant}
14333e519524SHoward Hinnant
14343e519524SHoward Hinnanttemplate <class _ForwardIterator1, class _ForwardIterator2>
143512f0a779SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
14363e519524SHoward Hinnant_ForwardIterator1
14373e519524SHoward Hinnantsearch(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
14383e519524SHoward Hinnant       _ForwardIterator2 __first2, _ForwardIterator2 __last2)
14393e519524SHoward Hinnant{
144028cc4ddeSMarshall Clow    typedef typename iterator_traits<_ForwardIterator1>::value_type __v1;
144128cc4ddeSMarshall Clow    typedef typename iterator_traits<_ForwardIterator2>::value_type __v2;
1442ce48a113SHoward Hinnant    return _VSTD::search(__first1, __last1, __first2, __last2, __equal_to<__v1, __v2>());
14433e519524SHoward Hinnant}
14443e519524SHoward Hinnant
1445d835e592SMarshall Clow
1446d835e592SMarshall Clow#if _LIBCPP_STD_VER > 14
1447d835e592SMarshall Clowtemplate <class _ForwardIterator, class _Searcher>
144812f0a779SMarshall Clow_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
1449d835e592SMarshall Clow_ForwardIterator search(_ForwardIterator __f, _ForwardIterator __l, const _Searcher &__s)
1450d835e592SMarshall Clow{ return __s(__f, __l).first; }
1451d835e592SMarshall Clow#endif
1452d835e592SMarshall Clow
14533e519524SHoward Hinnant// search_n
14543e519524SHoward Hinnant
14553e519524SHoward Hinnanttemplate <class _BinaryPredicate, class _ForwardIterator, class _Size, class _Tp>
145612f0a779SMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
14573e519524SHoward Hinnant__search_n(_ForwardIterator __first, _ForwardIterator __last,
1458e4383379SHoward Hinnant           _Size __count, const _Tp& __value_, _BinaryPredicate __pred, forward_iterator_tag)
14593e519524SHoward Hinnant{
14603e519524SHoward Hinnant    if (__count <= 0)
14613e519524SHoward Hinnant        return __first;
14623e519524SHoward Hinnant    while (true)
14633e519524SHoward Hinnant    {
1464e4383379SHoward Hinnant        // Find first element in sequence that matchs __value_, with a mininum of loop checks
14653e519524SHoward Hinnant        while (true)
14663e519524SHoward Hinnant        {
1467e4383379SHoward Hinnant            if (__first == __last)  // return __last if no element matches __value_
14683e519524SHoward Hinnant                return __last;
1469e4383379SHoward Hinnant            if (__pred(*__first, __value_))
14703e519524SHoward Hinnant                break;
14713e519524SHoward Hinnant            ++__first;
14723e519524SHoward Hinnant        }
1473e4383379SHoward Hinnant        // *__first matches __value_, now match elements after here
14743e519524SHoward Hinnant        _ForwardIterator __m = __first;
14753e519524SHoward Hinnant        _Size __c(0);
14763e519524SHoward Hinnant        while (true)
14773e519524SHoward Hinnant        {
14783e519524SHoward Hinnant            if (++__c == __count)  // If pattern exhausted, __first is the answer (works for 1 element pattern)
14793e519524SHoward Hinnant                return __first;
14803e519524SHoward Hinnant            if (++__m == __last)  // Otherwise if source exhaused, pattern not found
14813e519524SHoward Hinnant                return __last;
1482e4383379SHoward Hinnant            if (!__pred(*__m, __value_))  // if there is a mismatch, restart with a new __first
14833e519524SHoward Hinnant            {
14843e519524SHoward Hinnant                __first = __m;
14853e519524SHoward Hinnant                ++__first;
14863e519524SHoward Hinnant                break;
14873e519524SHoward Hinnant            }  // else there is a match, check next elements
14883e519524SHoward Hinnant        }
14893e519524SHoward Hinnant    }
14903e519524SHoward Hinnant}
14913e519524SHoward Hinnant
14923e519524SHoward Hinnanttemplate <class _BinaryPredicate, class _RandomAccessIterator, class _Size, class _Tp>
149312f0a779SMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 _RandomAccessIterator
14943e519524SHoward Hinnant__search_n(_RandomAccessIterator __first, _RandomAccessIterator __last,
1495e4383379SHoward Hinnant           _Size __count, const _Tp& __value_, _BinaryPredicate __pred, random_access_iterator_tag)
14963e519524SHoward Hinnant{
14973e519524SHoward Hinnant    if (__count <= 0)
14983e519524SHoward Hinnant        return __first;
14993e519524SHoward Hinnant    _Size __len = static_cast<_Size>(__last - __first);
15003e519524SHoward Hinnant    if (__len < __count)
15013e519524SHoward Hinnant        return __last;
15023e519524SHoward Hinnant    const _RandomAccessIterator __s = __last - (__count - 1);  // Start of pattern match can't go beyond here
15033e519524SHoward Hinnant    while (true)
15043e519524SHoward Hinnant    {
1505e4383379SHoward Hinnant        // Find first element in sequence that matchs __value_, with a mininum of loop checks
15063e519524SHoward Hinnant        while (true)
15073e519524SHoward Hinnant        {
1508b13fcad6SHoward Hinnant            if (__first >= __s)  // return __last if no element matches __value_
15093e519524SHoward Hinnant                return __last;
1510e4383379SHoward Hinnant            if (__pred(*__first, __value_))
15113e519524SHoward Hinnant                break;
15123e519524SHoward Hinnant            ++__first;
15133e519524SHoward Hinnant        }
1514e4383379SHoward Hinnant        // *__first matches __value_, now match elements after here
15153e519524SHoward Hinnant        _RandomAccessIterator __m = __first;
15163e519524SHoward Hinnant        _Size __c(0);
15173e519524SHoward Hinnant        while (true)
15183e519524SHoward Hinnant        {
15193e519524SHoward Hinnant            if (++__c == __count)  // If pattern exhausted, __first is the answer (works for 1 element pattern)
15203e519524SHoward Hinnant                return __first;
15213e519524SHoward Hinnant             ++__m;          // no need to check range on __m because __s guarantees we have enough source
1522e4383379SHoward Hinnant            if (!__pred(*__m, __value_))  // if there is a mismatch, restart with a new __first
15233e519524SHoward Hinnant            {
15243e519524SHoward Hinnant                __first = __m;
15253e519524SHoward Hinnant                ++__first;
15263e519524SHoward Hinnant                break;
15273e519524SHoward Hinnant            }  // else there is a match, check next elements
15283e519524SHoward Hinnant        }
15293e519524SHoward Hinnant    }
15303e519524SHoward Hinnant}
15313e519524SHoward Hinnant
15323e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Size, class _Tp, class _BinaryPredicate>
153312f0a779SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
15343e519524SHoward Hinnant_ForwardIterator
15353e519524SHoward Hinnantsearch_n(_ForwardIterator __first, _ForwardIterator __last,
1536e4383379SHoward Hinnant         _Size __count, const _Tp& __value_, _BinaryPredicate __pred)
15373e519524SHoward Hinnant{
1538ce48a113SHoward Hinnant    return _VSTD::__search_n<typename add_lvalue_reference<_BinaryPredicate>::type>
153951544023SEric Fiselier           (__first, __last, __convert_to_integral(__count), __value_, __pred,
154051544023SEric Fiselier           typename iterator_traits<_ForwardIterator>::iterator_category());
15413e519524SHoward Hinnant}
15423e519524SHoward Hinnant
15433e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Size, class _Tp>
154412f0a779SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
15453e519524SHoward Hinnant_ForwardIterator
1546e4383379SHoward Hinnantsearch_n(_ForwardIterator __first, _ForwardIterator __last, _Size __count, const _Tp& __value_)
15473e519524SHoward Hinnant{
15483e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator>::value_type __v;
154951544023SEric Fiselier    return _VSTD::search_n(__first, __last, __convert_to_integral(__count),
155051544023SEric Fiselier                           __value_, __equal_to<__v, _Tp>());
15513e519524SHoward Hinnant}
15523e519524SHoward Hinnant
15533e519524SHoward Hinnant// copy
15543e519524SHoward Hinnanttemplate <class _Iter>
15553e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
15563e519524SHoward Hinnant_Iter
15573e519524SHoward Hinnant__unwrap_iter(_Iter __i)
15583e519524SHoward Hinnant{
15593e519524SHoward Hinnant    return __i;
15603e519524SHoward Hinnant}
15613e519524SHoward Hinnant
15623e519524SHoward Hinnanttemplate <class _Tp>
15635b7c98e5SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY
15643e519524SHoward Hinnanttypename enable_if
15653e519524SHoward Hinnant<
1566ca740483SHoward Hinnant    is_trivially_copy_assignable<_Tp>::value,
15673e519524SHoward Hinnant    _Tp*
15683e519524SHoward Hinnant>::type
15693e519524SHoward Hinnant__unwrap_iter(move_iterator<_Tp*> __i)
15703e519524SHoward Hinnant{
15713e519524SHoward Hinnant    return __i.base();
15723e519524SHoward Hinnant}
15733e519524SHoward Hinnant
1574fc88dbd2SHoward Hinnant#if _LIBCPP_DEBUG_LEVEL < 2
1575fc88dbd2SHoward Hinnant
15763e519524SHoward Hinnanttemplate <class _Tp>
15779cad5025SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
15783e519524SHoward Hinnanttypename enable_if
15793e519524SHoward Hinnant<
1580ca740483SHoward Hinnant    is_trivially_copy_assignable<_Tp>::value,
15813e519524SHoward Hinnant    _Tp*
15823e519524SHoward Hinnant>::type
15833e519524SHoward Hinnant__unwrap_iter(__wrap_iter<_Tp*> __i)
15843e519524SHoward Hinnant{
15853e519524SHoward Hinnant    return __i.base();
15863e519524SHoward Hinnant}
15873e519524SHoward Hinnant
158814bd0bf0SEric Fiselier#else
158914bd0bf0SEric Fiselier
159014bd0bf0SEric Fiseliertemplate <class _Tp>
15919cad5025SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
159214bd0bf0SEric Fiseliertypename enable_if
159314bd0bf0SEric Fiselier<
159414bd0bf0SEric Fiselier    is_trivially_copy_assignable<_Tp>::value,
159514bd0bf0SEric Fiselier    __wrap_iter<_Tp*>
159614bd0bf0SEric Fiselier>::type
159714bd0bf0SEric Fiselier__unwrap_iter(__wrap_iter<_Tp*> __i)
159814bd0bf0SEric Fiselier{
159914bd0bf0SEric Fiselier    return __i;
160014bd0bf0SEric Fiselier}
160114bd0bf0SEric Fiselier
1602fc88dbd2SHoward Hinnant#endif  // _LIBCPP_DEBUG_LEVEL < 2
1603fc88dbd2SHoward Hinnant
16043e519524SHoward Hinnanttemplate <class _InputIterator, class _OutputIterator>
16053e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
16063e519524SHoward Hinnant_OutputIterator
16073e519524SHoward Hinnant__copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
16083e519524SHoward Hinnant{
1609910285b2SEric Fiselier    for (; __first != __last; ++__first, (void) ++__result)
16103e519524SHoward Hinnant        *__result = *__first;
16113e519524SHoward Hinnant    return __result;
16123e519524SHoward Hinnant}
16133e519524SHoward Hinnant
16143e519524SHoward Hinnanttemplate <class _Tp, class _Up>
16153e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
16163e519524SHoward Hinnanttypename enable_if
16173e519524SHoward Hinnant<
16183e519524SHoward Hinnant    is_same<typename remove_const<_Tp>::type, _Up>::value &&
1619ca740483SHoward Hinnant    is_trivially_copy_assignable<_Up>::value,
16203e519524SHoward Hinnant    _Up*
16213e519524SHoward Hinnant>::type
16223e519524SHoward Hinnant__copy(_Tp* __first, _Tp* __last, _Up* __result)
16233e519524SHoward Hinnant{
16243e519524SHoward Hinnant    const size_t __n = static_cast<size_t>(__last - __first);
16255b312052SMarshall Clow    if (__n > 0)
1626ce48a113SHoward Hinnant        _VSTD::memmove(__result, __first, __n * sizeof(_Up));
16273e519524SHoward Hinnant    return __result + __n;
16283e519524SHoward Hinnant}
16293e519524SHoward Hinnant
16303e519524SHoward Hinnanttemplate <class _InputIterator, class _OutputIterator>
16313e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
16323e519524SHoward Hinnant_OutputIterator
16333e519524SHoward Hinnantcopy(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
16343e519524SHoward Hinnant{
1635ce48a113SHoward Hinnant    return _VSTD::__copy(__unwrap_iter(__first), __unwrap_iter(__last), __unwrap_iter(__result));
16363e519524SHoward Hinnant}
16373e519524SHoward Hinnant
16383e519524SHoward Hinnant// copy_backward
16393e519524SHoward Hinnant
1640d3d4356fSHoward Hinnanttemplate <class _BidirectionalIterator, class _OutputIterator>
16413e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
16423e519524SHoward Hinnant_OutputIterator
1643d3d4356fSHoward Hinnant__copy_backward(_BidirectionalIterator __first, _BidirectionalIterator __last, _OutputIterator __result)
16443e519524SHoward Hinnant{
16453e519524SHoward Hinnant    while (__first != __last)
16463e519524SHoward Hinnant        *--__result = *--__last;
16473e519524SHoward Hinnant    return __result;
16483e519524SHoward Hinnant}
16493e519524SHoward Hinnant
16503e519524SHoward Hinnanttemplate <class _Tp, class _Up>
16513e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
16523e519524SHoward Hinnanttypename enable_if
16533e519524SHoward Hinnant<
16543e519524SHoward Hinnant    is_same<typename remove_const<_Tp>::type, _Up>::value &&
1655ca740483SHoward Hinnant    is_trivially_copy_assignable<_Up>::value,
16563e519524SHoward Hinnant    _Up*
16573e519524SHoward Hinnant>::type
16583e519524SHoward Hinnant__copy_backward(_Tp* __first, _Tp* __last, _Up* __result)
16593e519524SHoward Hinnant{
16603e519524SHoward Hinnant    const size_t __n = static_cast<size_t>(__last - __first);
16615b312052SMarshall Clow    if (__n > 0)
16625b312052SMarshall Clow    {
16633e519524SHoward Hinnant        __result -= __n;
1664ce48a113SHoward Hinnant        _VSTD::memmove(__result, __first, __n * sizeof(_Up));
16655b312052SMarshall Clow    }
16663e519524SHoward Hinnant    return __result;
16673e519524SHoward Hinnant}
16683e519524SHoward Hinnant
16693e519524SHoward Hinnanttemplate <class _BidirectionalIterator1, class _BidirectionalIterator2>
16703e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
16713e519524SHoward Hinnant_BidirectionalIterator2
16723e519524SHoward Hinnantcopy_backward(_BidirectionalIterator1 __first, _BidirectionalIterator1 __last,
16733e519524SHoward Hinnant              _BidirectionalIterator2 __result)
16743e519524SHoward Hinnant{
1675fd838227SEric Fiselier    return _VSTD::__copy_backward(__unwrap_iter(__first),
1676fd838227SEric Fiselier                                  __unwrap_iter(__last),
1677fd838227SEric Fiselier                                  __unwrap_iter(__result));
16783e519524SHoward Hinnant}
16793e519524SHoward Hinnant
16803e519524SHoward Hinnant// copy_if
16813e519524SHoward Hinnant
16823e519524SHoward Hinnanttemplate<class _InputIterator, class _OutputIterator, class _Predicate>
16833e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
16843e519524SHoward Hinnant_OutputIterator
16853e519524SHoward Hinnantcopy_if(_InputIterator __first, _InputIterator __last,
16863e519524SHoward Hinnant        _OutputIterator __result, _Predicate __pred)
16873e519524SHoward Hinnant{
16883e519524SHoward Hinnant    for (; __first != __last; ++__first)
16893e519524SHoward Hinnant    {
16903e519524SHoward Hinnant        if (__pred(*__first))
16913e519524SHoward Hinnant        {
16923e519524SHoward Hinnant            *__result = *__first;
16933e519524SHoward Hinnant            ++__result;
16943e519524SHoward Hinnant        }
16953e519524SHoward Hinnant    }
16963e519524SHoward Hinnant    return __result;
16973e519524SHoward Hinnant}
16983e519524SHoward Hinnant
16993e519524SHoward Hinnant// copy_n
17003e519524SHoward Hinnant
17013e519524SHoward Hinnanttemplate<class _InputIterator, class _Size, class _OutputIterator>
17023e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
17033e519524SHoward Hinnanttypename enable_if
17043e519524SHoward Hinnant<
17053e519524SHoward Hinnant    __is_input_iterator<_InputIterator>::value &&
17063e519524SHoward Hinnant   !__is_random_access_iterator<_InputIterator>::value,
17073e519524SHoward Hinnant    _OutputIterator
17083e519524SHoward Hinnant>::type
170951544023SEric Fiseliercopy_n(_InputIterator __first, _Size __orig_n, _OutputIterator __result)
17103e519524SHoward Hinnant{
171151544023SEric Fiselier    typedef decltype(__convert_to_integral(__orig_n)) _IntegralSize;
171251544023SEric Fiselier    _IntegralSize __n = __orig_n;
171399847d2bSHoward Hinnant    if (__n > 0)
171499847d2bSHoward Hinnant    {
17153e519524SHoward Hinnant        *__result = *__first;
171699847d2bSHoward Hinnant        ++__result;
171799847d2bSHoward Hinnant        for (--__n; __n > 0; --__n)
171899847d2bSHoward Hinnant        {
171999847d2bSHoward Hinnant            ++__first;
172099847d2bSHoward Hinnant            *__result = *__first;
172199847d2bSHoward Hinnant            ++__result;
172299847d2bSHoward Hinnant        }
172399847d2bSHoward Hinnant    }
17243e519524SHoward Hinnant    return __result;
17253e519524SHoward Hinnant}
17263e519524SHoward Hinnant
17273e519524SHoward Hinnanttemplate<class _InputIterator, class _Size, class _OutputIterator>
17283e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
17293e519524SHoward Hinnanttypename enable_if
17303e519524SHoward Hinnant<
17313e519524SHoward Hinnant    __is_random_access_iterator<_InputIterator>::value,
17323e519524SHoward Hinnant    _OutputIterator
17333e519524SHoward Hinnant>::type
173451544023SEric Fiseliercopy_n(_InputIterator __first, _Size __orig_n, _OutputIterator __result)
17353e519524SHoward Hinnant{
173651544023SEric Fiselier    typedef decltype(__convert_to_integral(__orig_n)) _IntegralSize;
173751544023SEric Fiselier    _IntegralSize __n = __orig_n;
1738ce48a113SHoward Hinnant    return _VSTD::copy(__first, __first + __n, __result);
17393e519524SHoward Hinnant}
17403e519524SHoward Hinnant
17413e519524SHoward Hinnant// move
17423e519524SHoward Hinnant
17433e519524SHoward Hinnanttemplate <class _InputIterator, class _OutputIterator>
17443e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
17453e519524SHoward Hinnant_OutputIterator
17463e519524SHoward Hinnant__move(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
17473e519524SHoward Hinnant{
1748910285b2SEric Fiselier    for (; __first != __last; ++__first, (void) ++__result)
1749ce48a113SHoward Hinnant        *__result = _VSTD::move(*__first);
17503e519524SHoward Hinnant    return __result;
17513e519524SHoward Hinnant}
17523e519524SHoward Hinnant
17533e519524SHoward Hinnanttemplate <class _Tp, class _Up>
17543e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
17553e519524SHoward Hinnanttypename enable_if
17563e519524SHoward Hinnant<
17573e519524SHoward Hinnant    is_same<typename remove_const<_Tp>::type, _Up>::value &&
1758ca740483SHoward Hinnant    is_trivially_copy_assignable<_Up>::value,
17593e519524SHoward Hinnant    _Up*
17603e519524SHoward Hinnant>::type
17613e519524SHoward Hinnant__move(_Tp* __first, _Tp* __last, _Up* __result)
17623e519524SHoward Hinnant{
17633e519524SHoward Hinnant    const size_t __n = static_cast<size_t>(__last - __first);
17645b312052SMarshall Clow    if (__n > 0)
1765ce48a113SHoward Hinnant        _VSTD::memmove(__result, __first, __n * sizeof(_Up));
17663e519524SHoward Hinnant    return __result + __n;
17673e519524SHoward Hinnant}
17683e519524SHoward Hinnant
17693e519524SHoward Hinnanttemplate <class _InputIterator, class _OutputIterator>
17703e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
17713e519524SHoward Hinnant_OutputIterator
17723e519524SHoward Hinnantmove(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
17733e519524SHoward Hinnant{
1774ce48a113SHoward Hinnant    return _VSTD::__move(__unwrap_iter(__first), __unwrap_iter(__last), __unwrap_iter(__result));
17753e519524SHoward Hinnant}
17763e519524SHoward Hinnant
17773e519524SHoward Hinnant// move_backward
17783e519524SHoward Hinnant
17793e519524SHoward Hinnanttemplate <class _InputIterator, class _OutputIterator>
17803e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
17813e519524SHoward Hinnant_OutputIterator
17823e519524SHoward Hinnant__move_backward(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
17833e519524SHoward Hinnant{
17843e519524SHoward Hinnant    while (__first != __last)
1785ce48a113SHoward Hinnant        *--__result = _VSTD::move(*--__last);
17863e519524SHoward Hinnant    return __result;
17873e519524SHoward Hinnant}
17883e519524SHoward Hinnant
17893e519524SHoward Hinnanttemplate <class _Tp, class _Up>
17903e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
17913e519524SHoward Hinnanttypename enable_if
17923e519524SHoward Hinnant<
17933e519524SHoward Hinnant    is_same<typename remove_const<_Tp>::type, _Up>::value &&
1794ca740483SHoward Hinnant    is_trivially_copy_assignable<_Up>::value,
17953e519524SHoward Hinnant    _Up*
17963e519524SHoward Hinnant>::type
17973e519524SHoward Hinnant__move_backward(_Tp* __first, _Tp* __last, _Up* __result)
17983e519524SHoward Hinnant{
17993e519524SHoward Hinnant    const size_t __n = static_cast<size_t>(__last - __first);
18005b312052SMarshall Clow    if (__n > 0)
18015b312052SMarshall Clow    {
18023e519524SHoward Hinnant        __result -= __n;
1803ce48a113SHoward Hinnant        _VSTD::memmove(__result, __first, __n * sizeof(_Up));
18045b312052SMarshall Clow    }
18053e519524SHoward Hinnant    return __result;
18063e519524SHoward Hinnant}
18073e519524SHoward Hinnant
18083e519524SHoward Hinnanttemplate <class _BidirectionalIterator1, class _BidirectionalIterator2>
18093e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
18103e519524SHoward Hinnant_BidirectionalIterator2
18113e519524SHoward Hinnantmove_backward(_BidirectionalIterator1 __first, _BidirectionalIterator1 __last,
18123e519524SHoward Hinnant              _BidirectionalIterator2 __result)
18133e519524SHoward Hinnant{
1814ce48a113SHoward Hinnant    return _VSTD::__move_backward(__unwrap_iter(__first), __unwrap_iter(__last), __unwrap_iter(__result));
18153e519524SHoward Hinnant}
18163e519524SHoward Hinnant
18173e519524SHoward Hinnant// iter_swap
18183e519524SHoward Hinnant
1819a676f7d3SHoward Hinnant// moved to <type_traits> for better swap / noexcept support
18203e519524SHoward Hinnant
18213e519524SHoward Hinnant// transform
18223e519524SHoward Hinnant
18233e519524SHoward Hinnanttemplate <class _InputIterator, class _OutputIterator, class _UnaryOperation>
182499894b61SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
18253e519524SHoward Hinnant_OutputIterator
18263e519524SHoward Hinnanttransform(_InputIterator __first, _InputIterator __last, _OutputIterator __result, _UnaryOperation __op)
18273e519524SHoward Hinnant{
1828910285b2SEric Fiselier    for (; __first != __last; ++__first, (void) ++__result)
18293e519524SHoward Hinnant        *__result = __op(*__first);
18303e519524SHoward Hinnant    return __result;
18313e519524SHoward Hinnant}
18323e519524SHoward Hinnant
18333e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _BinaryOperation>
183499894b61SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
18353e519524SHoward Hinnant_OutputIterator
18363e519524SHoward Hinnanttransform(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2,
18373e519524SHoward Hinnant          _OutputIterator __result, _BinaryOperation __binary_op)
18383e519524SHoward Hinnant{
1839910285b2SEric Fiselier    for (; __first1 != __last1; ++__first1, (void) ++__first2, ++__result)
18403e519524SHoward Hinnant        *__result = __binary_op(*__first1, *__first2);
18413e519524SHoward Hinnant    return __result;
18423e519524SHoward Hinnant}
18433e519524SHoward Hinnant
18443e519524SHoward Hinnant// replace
18453e519524SHoward Hinnant
18463e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Tp>
184712c7423fSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
18483e519524SHoward Hinnantvoid
18493e519524SHoward Hinnantreplace(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __old_value, const _Tp& __new_value)
18503e519524SHoward Hinnant{
18513e519524SHoward Hinnant    for (; __first != __last; ++__first)
18523e519524SHoward Hinnant        if (*__first == __old_value)
18533e519524SHoward Hinnant            *__first = __new_value;
18543e519524SHoward Hinnant}
18553e519524SHoward Hinnant
18563e519524SHoward Hinnant// replace_if
18573e519524SHoward Hinnant
18583e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Predicate, class _Tp>
185912c7423fSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
18603e519524SHoward Hinnantvoid
18613e519524SHoward Hinnantreplace_if(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred, const _Tp& __new_value)
18623e519524SHoward Hinnant{
18633e519524SHoward Hinnant    for (; __first != __last; ++__first)
18643e519524SHoward Hinnant        if (__pred(*__first))
18653e519524SHoward Hinnant            *__first = __new_value;
18663e519524SHoward Hinnant}
18673e519524SHoward Hinnant
18683e519524SHoward Hinnant// replace_copy
18693e519524SHoward Hinnant
18703e519524SHoward Hinnanttemplate <class _InputIterator, class _OutputIterator, class _Tp>
187112c7423fSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
18723e519524SHoward Hinnant_OutputIterator
18733e519524SHoward Hinnantreplace_copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result,
18743e519524SHoward Hinnant             const _Tp& __old_value, const _Tp& __new_value)
18753e519524SHoward Hinnant{
1876910285b2SEric Fiselier    for (; __first != __last; ++__first, (void) ++__result)
18773e519524SHoward Hinnant        if (*__first == __old_value)
18783e519524SHoward Hinnant            *__result = __new_value;
18793e519524SHoward Hinnant        else
18803e519524SHoward Hinnant            *__result = *__first;
18813e519524SHoward Hinnant    return __result;
18823e519524SHoward Hinnant}
18833e519524SHoward Hinnant
18843e519524SHoward Hinnant// replace_copy_if
18853e519524SHoward Hinnant
18863e519524SHoward Hinnanttemplate <class _InputIterator, class _OutputIterator, class _Predicate, class _Tp>
188712c7423fSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
18883e519524SHoward Hinnant_OutputIterator
18893e519524SHoward Hinnantreplace_copy_if(_InputIterator __first, _InputIterator __last, _OutputIterator __result,
18903e519524SHoward Hinnant                _Predicate __pred, const _Tp& __new_value)
18913e519524SHoward Hinnant{
1892910285b2SEric Fiselier    for (; __first != __last; ++__first, (void) ++__result)
18933e519524SHoward Hinnant        if (__pred(*__first))
18943e519524SHoward Hinnant            *__result = __new_value;
18953e519524SHoward Hinnant        else
18963e519524SHoward Hinnant            *__result = *__first;
18973e519524SHoward Hinnant    return __result;
18983e519524SHoward Hinnant}
18993e519524SHoward Hinnant
19003e519524SHoward Hinnant// fill_n
19013e519524SHoward Hinnant
19023e519524SHoward Hinnanttemplate <class _OutputIterator, class _Size, class _Tp>
19034bfb9313SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
19043e519524SHoward Hinnant_OutputIterator
19050f242beaSHoward Hinnant__fill_n(_OutputIterator __first, _Size __n, const _Tp& __value_)
19063e519524SHoward Hinnant{
1907910285b2SEric Fiselier    for (; __n > 0; ++__first, (void) --__n)
1908e4383379SHoward Hinnant        *__first = __value_;
19093e519524SHoward Hinnant    return __first;
19103e519524SHoward Hinnant}
19113e519524SHoward Hinnant
19123e519524SHoward Hinnanttemplate <class _OutputIterator, class _Size, class _Tp>
19134bfb9313SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
19143e519524SHoward Hinnant_OutputIterator
1915e4383379SHoward Hinnantfill_n(_OutputIterator __first, _Size __n, const _Tp& __value_)
19163e519524SHoward Hinnant{
191751544023SEric Fiselier   return _VSTD::__fill_n(__first, __convert_to_integral(__n), __value_);
19183e519524SHoward Hinnant}
19193e519524SHoward Hinnant
19203e519524SHoward Hinnant// fill
19213e519524SHoward Hinnant
19223e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Tp>
19234bfb9313SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
19243e519524SHoward Hinnantvoid
1925e4383379SHoward Hinnant__fill(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, forward_iterator_tag)
19263e519524SHoward Hinnant{
19273e519524SHoward Hinnant    for (; __first != __last; ++__first)
1928e4383379SHoward Hinnant        *__first = __value_;
19293e519524SHoward Hinnant}
19303e519524SHoward Hinnant
19313e519524SHoward Hinnanttemplate <class _RandomAccessIterator, class _Tp>
19324bfb9313SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
19333e519524SHoward Hinnantvoid
1934e4383379SHoward Hinnant__fill(_RandomAccessIterator __first, _RandomAccessIterator __last, const _Tp& __value_, random_access_iterator_tag)
19353e519524SHoward Hinnant{
1936e4383379SHoward Hinnant    _VSTD::fill_n(__first, __last - __first, __value_);
19373e519524SHoward Hinnant}
19383e519524SHoward Hinnant
19393e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Tp>
19404bfb9313SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
19413e519524SHoward Hinnantvoid
1942e4383379SHoward Hinnantfill(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_)
19433e519524SHoward Hinnant{
1944e4383379SHoward Hinnant    _VSTD::__fill(__first, __last, __value_, typename iterator_traits<_ForwardIterator>::iterator_category());
19453e519524SHoward Hinnant}
19463e519524SHoward Hinnant
19473e519524SHoward Hinnant// generate
19483e519524SHoward Hinnant
19493e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Generator>
19504bfb9313SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
19513e519524SHoward Hinnantvoid
19523e519524SHoward Hinnantgenerate(_ForwardIterator __first, _ForwardIterator __last, _Generator __gen)
19533e519524SHoward Hinnant{
19543e519524SHoward Hinnant    for (; __first != __last; ++__first)
19553e519524SHoward Hinnant        *__first = __gen();
19563e519524SHoward Hinnant}
19573e519524SHoward Hinnant
19583e519524SHoward Hinnant// generate_n
19593e519524SHoward Hinnant
19603e519524SHoward Hinnanttemplate <class _OutputIterator, class _Size, class _Generator>
19614bfb9313SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY  _LIBCPP_CONSTEXPR_AFTER_CXX17
19623e519524SHoward Hinnant_OutputIterator
196351544023SEric Fiseliergenerate_n(_OutputIterator __first, _Size __orig_n, _Generator __gen)
19643e519524SHoward Hinnant{
196551544023SEric Fiselier    typedef decltype(__convert_to_integral(__orig_n)) _IntegralSize;
196651544023SEric Fiselier    _IntegralSize __n = __orig_n;
1967910285b2SEric Fiselier    for (; __n > 0; ++__first, (void) --__n)
19683e519524SHoward Hinnant        *__first = __gen();
19693e519524SHoward Hinnant    return __first;
19703e519524SHoward Hinnant}
19713e519524SHoward Hinnant
19723e519524SHoward Hinnant// remove
19733e519524SHoward Hinnant
19743e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Tp>
1975e8ea8296SMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
1976e4383379SHoward Hinnantremove(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_)
19773e519524SHoward Hinnant{
1978e4383379SHoward Hinnant    __first = _VSTD::find(__first, __last, __value_);
19793e519524SHoward Hinnant    if (__first != __last)
19803e519524SHoward Hinnant    {
19813e519524SHoward Hinnant        _ForwardIterator __i = __first;
19823e519524SHoward Hinnant        while (++__i != __last)
19833e519524SHoward Hinnant        {
1984e4383379SHoward Hinnant            if (!(*__i == __value_))
19853e519524SHoward Hinnant            {
1986ce48a113SHoward Hinnant                *__first = _VSTD::move(*__i);
19873e519524SHoward Hinnant                ++__first;
19883e519524SHoward Hinnant            }
19893e519524SHoward Hinnant        }
19903e519524SHoward Hinnant    }
19913e519524SHoward Hinnant    return __first;
19923e519524SHoward Hinnant}
19933e519524SHoward Hinnant
19943e519524SHoward Hinnant// remove_if
19953e519524SHoward Hinnant
19963e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Predicate>
1997e8ea8296SMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
19983e519524SHoward Hinnantremove_if(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred)
19993e519524SHoward Hinnant{
2000ce48a113SHoward Hinnant    __first = _VSTD::find_if<_ForwardIterator, typename add_lvalue_reference<_Predicate>::type>
20013e519524SHoward Hinnant                           (__first, __last, __pred);
20023e519524SHoward Hinnant    if (__first != __last)
20033e519524SHoward Hinnant    {
20043e519524SHoward Hinnant        _ForwardIterator __i = __first;
20053e519524SHoward Hinnant        while (++__i != __last)
20063e519524SHoward Hinnant        {
20073e519524SHoward Hinnant            if (!__pred(*__i))
20083e519524SHoward Hinnant            {
2009ce48a113SHoward Hinnant                *__first = _VSTD::move(*__i);
20103e519524SHoward Hinnant                ++__first;
20113e519524SHoward Hinnant            }
20123e519524SHoward Hinnant        }
20133e519524SHoward Hinnant    }
20143e519524SHoward Hinnant    return __first;
20153e519524SHoward Hinnant}
20163e519524SHoward Hinnant
20173e519524SHoward Hinnant// remove_copy
20183e519524SHoward Hinnant
20193e519524SHoward Hinnanttemplate <class _InputIterator, class _OutputIterator, class _Tp>
2020e8ea8296SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
20213e519524SHoward Hinnant_OutputIterator
2022e4383379SHoward Hinnantremove_copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result, const _Tp& __value_)
20233e519524SHoward Hinnant{
20243e519524SHoward Hinnant    for (; __first != __last; ++__first)
20253e519524SHoward Hinnant    {
2026e4383379SHoward Hinnant        if (!(*__first == __value_))
20273e519524SHoward Hinnant        {
20283e519524SHoward Hinnant            *__result = *__first;
20293e519524SHoward Hinnant            ++__result;
20303e519524SHoward Hinnant        }
20313e519524SHoward Hinnant    }
20323e519524SHoward Hinnant    return __result;
20333e519524SHoward Hinnant}
20343e519524SHoward Hinnant
20353e519524SHoward Hinnant// remove_copy_if
20363e519524SHoward Hinnant
20373e519524SHoward Hinnanttemplate <class _InputIterator, class _OutputIterator, class _Predicate>
2038e8ea8296SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
20393e519524SHoward Hinnant_OutputIterator
20403e519524SHoward Hinnantremove_copy_if(_InputIterator __first, _InputIterator __last, _OutputIterator __result, _Predicate __pred)
20413e519524SHoward Hinnant{
20423e519524SHoward Hinnant    for (; __first != __last; ++__first)
20433e519524SHoward Hinnant    {
20443e519524SHoward Hinnant        if (!__pred(*__first))
20453e519524SHoward Hinnant        {
20463e519524SHoward Hinnant            *__result = *__first;
20473e519524SHoward Hinnant            ++__result;
20483e519524SHoward Hinnant        }
20493e519524SHoward Hinnant    }
20503e519524SHoward Hinnant    return __result;
20513e519524SHoward Hinnant}
20523e519524SHoward Hinnant
20533e519524SHoward Hinnant// unique
20543e519524SHoward Hinnant
20553e519524SHoward Hinnanttemplate <class _ForwardIterator, class _BinaryPredicate>
20564bfb9313SMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
20573e519524SHoward Hinnantunique(_ForwardIterator __first, _ForwardIterator __last, _BinaryPredicate __pred)
20583e519524SHoward Hinnant{
2059ce48a113SHoward Hinnant    __first = _VSTD::adjacent_find<_ForwardIterator, typename add_lvalue_reference<_BinaryPredicate>::type>
20603e519524SHoward Hinnant                                 (__first, __last, __pred);
20613e519524SHoward Hinnant    if (__first != __last)
20623e519524SHoward Hinnant    {
20633e519524SHoward Hinnant        // ...  a  a  ?  ...
20643e519524SHoward Hinnant        //      f     i
20653e519524SHoward Hinnant        _ForwardIterator __i = __first;
20663e519524SHoward Hinnant        for (++__i; ++__i != __last;)
20673e519524SHoward Hinnant            if (!__pred(*__first, *__i))
2068ce48a113SHoward Hinnant                *++__first = _VSTD::move(*__i);
20693e519524SHoward Hinnant        ++__first;
20703e519524SHoward Hinnant    }
20713e519524SHoward Hinnant    return __first;
20723e519524SHoward Hinnant}
20733e519524SHoward Hinnant
20743e519524SHoward Hinnanttemplate <class _ForwardIterator>
20754bfb9313SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
20763e519524SHoward Hinnant_ForwardIterator
20773e519524SHoward Hinnantunique(_ForwardIterator __first, _ForwardIterator __last)
20783e519524SHoward Hinnant{
20793e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator>::value_type __v;
2080ce48a113SHoward Hinnant    return _VSTD::unique(__first, __last, __equal_to<__v>());
20813e519524SHoward Hinnant}
20823e519524SHoward Hinnant
20833e519524SHoward Hinnant// unique_copy
20843e519524SHoward Hinnant
20853e519524SHoward Hinnanttemplate <class _BinaryPredicate, class _InputIterator, class _OutputIterator>
20864bfb9313SMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 _OutputIterator
20873e519524SHoward Hinnant__unique_copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result, _BinaryPredicate __pred,
20883e519524SHoward Hinnant              input_iterator_tag, output_iterator_tag)
20893e519524SHoward Hinnant{
20903e519524SHoward Hinnant    if (__first != __last)
20913e519524SHoward Hinnant    {
20923e519524SHoward Hinnant        typename iterator_traits<_InputIterator>::value_type __t(*__first);
20933e519524SHoward Hinnant        *__result = __t;
20943e519524SHoward Hinnant        ++__result;
20953e519524SHoward Hinnant        while (++__first != __last)
20963e519524SHoward Hinnant        {
20973e519524SHoward Hinnant            if (!__pred(__t, *__first))
20983e519524SHoward Hinnant            {
20993e519524SHoward Hinnant                __t = *__first;
21003e519524SHoward Hinnant                *__result = __t;
21013e519524SHoward Hinnant                ++__result;
21023e519524SHoward Hinnant            }
21033e519524SHoward Hinnant        }
21043e519524SHoward Hinnant    }
21053e519524SHoward Hinnant    return __result;
21063e519524SHoward Hinnant}
21073e519524SHoward Hinnant
21083e519524SHoward Hinnanttemplate <class _BinaryPredicate, class _ForwardIterator, class _OutputIterator>
21094bfb9313SMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 _OutputIterator
21103e519524SHoward Hinnant__unique_copy(_ForwardIterator __first, _ForwardIterator __last, _OutputIterator __result, _BinaryPredicate __pred,
21113e519524SHoward Hinnant              forward_iterator_tag, output_iterator_tag)
21123e519524SHoward Hinnant{
21133e519524SHoward Hinnant    if (__first != __last)
21143e519524SHoward Hinnant    {
21153e519524SHoward Hinnant        _ForwardIterator __i = __first;
21163e519524SHoward Hinnant        *__result = *__i;
21173e519524SHoward Hinnant        ++__result;
21183e519524SHoward Hinnant        while (++__first != __last)
21193e519524SHoward Hinnant        {
21203e519524SHoward Hinnant            if (!__pred(*__i, *__first))
21213e519524SHoward Hinnant            {
21223e519524SHoward Hinnant                *__result = *__first;
21233e519524SHoward Hinnant                ++__result;
21243e519524SHoward Hinnant                __i = __first;
21253e519524SHoward Hinnant            }
21263e519524SHoward Hinnant        }
21273e519524SHoward Hinnant    }
21283e519524SHoward Hinnant    return __result;
21293e519524SHoward Hinnant}
21303e519524SHoward Hinnant
21313e519524SHoward Hinnanttemplate <class _BinaryPredicate, class _InputIterator, class _ForwardIterator>
21324bfb9313SMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
21333e519524SHoward Hinnant__unique_copy(_InputIterator __first, _InputIterator __last, _ForwardIterator __result, _BinaryPredicate __pred,
21343e519524SHoward Hinnant              input_iterator_tag, forward_iterator_tag)
21353e519524SHoward Hinnant{
21363e519524SHoward Hinnant    if (__first != __last)
21373e519524SHoward Hinnant    {
21383e519524SHoward Hinnant        *__result = *__first;
21393e519524SHoward Hinnant        while (++__first != __last)
21403e519524SHoward Hinnant            if (!__pred(*__result, *__first))
21413e519524SHoward Hinnant                *++__result = *__first;
21423e519524SHoward Hinnant        ++__result;
21433e519524SHoward Hinnant    }
21443e519524SHoward Hinnant    return __result;
21453e519524SHoward Hinnant}
21463e519524SHoward Hinnant
21473e519524SHoward Hinnanttemplate <class _InputIterator, class _OutputIterator, class _BinaryPredicate>
21484bfb9313SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
21493e519524SHoward Hinnant_OutputIterator
21503e519524SHoward Hinnantunique_copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result, _BinaryPredicate __pred)
21513e519524SHoward Hinnant{
2152ce48a113SHoward Hinnant    return _VSTD::__unique_copy<typename add_lvalue_reference<_BinaryPredicate>::type>
21533e519524SHoward Hinnant                              (__first, __last, __result, __pred,
21543e519524SHoward Hinnant                               typename iterator_traits<_InputIterator>::iterator_category(),
21553e519524SHoward Hinnant                               typename iterator_traits<_OutputIterator>::iterator_category());
21563e519524SHoward Hinnant}
21573e519524SHoward Hinnant
21583e519524SHoward Hinnanttemplate <class _InputIterator, class _OutputIterator>
21594bfb9313SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
21603e519524SHoward Hinnant_OutputIterator
21613e519524SHoward Hinnantunique_copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
21623e519524SHoward Hinnant{
21633e519524SHoward Hinnant    typedef typename iterator_traits<_InputIterator>::value_type __v;
2164ce48a113SHoward Hinnant    return _VSTD::unique_copy(__first, __last, __result, __equal_to<__v>());
21653e519524SHoward Hinnant}
21663e519524SHoward Hinnant
21673e519524SHoward Hinnant// reverse
21683e519524SHoward Hinnant
21693e519524SHoward Hinnanttemplate <class _BidirectionalIterator>
21703e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
21713e519524SHoward Hinnantvoid
21723e519524SHoward Hinnant__reverse(_BidirectionalIterator __first, _BidirectionalIterator __last, bidirectional_iterator_tag)
21733e519524SHoward Hinnant{
21743e519524SHoward Hinnant    while (__first != __last)
21753e519524SHoward Hinnant    {
21763e519524SHoward Hinnant        if (__first == --__last)
21773e519524SHoward Hinnant            break;
2178def501d1SMarshall Clow        _VSTD::iter_swap(__first, __last);
21793e519524SHoward Hinnant        ++__first;
21803e519524SHoward Hinnant    }
21813e519524SHoward Hinnant}
21823e519524SHoward Hinnant
21833e519524SHoward Hinnanttemplate <class _RandomAccessIterator>
21843e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
21853e519524SHoward Hinnantvoid
21863e519524SHoward Hinnant__reverse(_RandomAccessIterator __first, _RandomAccessIterator __last, random_access_iterator_tag)
21873e519524SHoward Hinnant{
21883e519524SHoward Hinnant    if (__first != __last)
21893e519524SHoward Hinnant        for (; __first < --__last; ++__first)
2190def501d1SMarshall Clow            _VSTD::iter_swap(__first, __last);
21913e519524SHoward Hinnant}
21923e519524SHoward Hinnant
21933e519524SHoward Hinnanttemplate <class _BidirectionalIterator>
21943e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
21953e519524SHoward Hinnantvoid
21963e519524SHoward Hinnantreverse(_BidirectionalIterator __first, _BidirectionalIterator __last)
21973e519524SHoward Hinnant{
2198ce48a113SHoward Hinnant    _VSTD::__reverse(__first, __last, typename iterator_traits<_BidirectionalIterator>::iterator_category());
21993e519524SHoward Hinnant}
22003e519524SHoward Hinnant
22013e519524SHoward Hinnant// reverse_copy
22023e519524SHoward Hinnant
22033e519524SHoward Hinnanttemplate <class _BidirectionalIterator, class _OutputIterator>
2204e8ea8296SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
22053e519524SHoward Hinnant_OutputIterator
22063e519524SHoward Hinnantreverse_copy(_BidirectionalIterator __first, _BidirectionalIterator __last, _OutputIterator __result)
22073e519524SHoward Hinnant{
22083e519524SHoward Hinnant    for (; __first != __last; ++__result)
22093e519524SHoward Hinnant        *__result = *--__last;
22103e519524SHoward Hinnant    return __result;
22113e519524SHoward Hinnant}
22123e519524SHoward Hinnant
22133e519524SHoward Hinnant// rotate
22143e519524SHoward Hinnant
22153e519524SHoward Hinnanttemplate <class _ForwardIterator>
22163e519524SHoward Hinnant_ForwardIterator
2217aca09de3SHoward Hinnant__rotate_left(_ForwardIterator __first, _ForwardIterator __last)
22183e519524SHoward Hinnant{
2219aca09de3SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
2220aca09de3SHoward Hinnant    value_type __tmp = _VSTD::move(*__first);
2221aca09de3SHoward Hinnant    _ForwardIterator __lm1 = _VSTD::move(_VSTD::next(__first), __last, __first);
2222aca09de3SHoward Hinnant    *__lm1 = _VSTD::move(__tmp);
2223aca09de3SHoward Hinnant    return __lm1;
2224aca09de3SHoward Hinnant}
2225aca09de3SHoward Hinnant
2226aca09de3SHoward Hinnanttemplate <class _BidirectionalIterator>
2227aca09de3SHoward Hinnant_BidirectionalIterator
2228aca09de3SHoward Hinnant__rotate_right(_BidirectionalIterator __first, _BidirectionalIterator __last)
2229aca09de3SHoward Hinnant{
2230aca09de3SHoward Hinnant    typedef typename iterator_traits<_BidirectionalIterator>::value_type value_type;
2231aca09de3SHoward Hinnant    _BidirectionalIterator __lm1 = _VSTD::prev(__last);
2232aca09de3SHoward Hinnant    value_type __tmp = _VSTD::move(*__lm1);
2233aca09de3SHoward Hinnant    _BidirectionalIterator __fp1 = _VSTD::move_backward(__first, __lm1, __last);
2234aca09de3SHoward Hinnant    *__first = _VSTD::move(__tmp);
2235aca09de3SHoward Hinnant    return __fp1;
2236aca09de3SHoward Hinnant}
2237aca09de3SHoward Hinnant
2238aca09de3SHoward Hinnanttemplate <class _ForwardIterator>
2239aca09de3SHoward Hinnant_ForwardIterator
2240aca09de3SHoward Hinnant__rotate_forward(_ForwardIterator __first, _ForwardIterator __middle, _ForwardIterator __last)
2241aca09de3SHoward Hinnant{
22423e519524SHoward Hinnant    _ForwardIterator __i = __middle;
22433e519524SHoward Hinnant    while (true)
22443e519524SHoward Hinnant    {
22453e519524SHoward Hinnant        swap(*__first, *__i);
22463e519524SHoward Hinnant        ++__first;
22473e519524SHoward Hinnant        if (++__i == __last)
22483e519524SHoward Hinnant            break;
22493e519524SHoward Hinnant        if (__first == __middle)
22503e519524SHoward Hinnant            __middle = __i;
22513e519524SHoward Hinnant    }
22523e519524SHoward Hinnant    _ForwardIterator __r = __first;
22533e519524SHoward Hinnant    if (__first != __middle)
22543e519524SHoward Hinnant    {
22553e519524SHoward Hinnant        __i = __middle;
22563e519524SHoward Hinnant        while (true)
22573e519524SHoward Hinnant        {
22583e519524SHoward Hinnant            swap(*__first, *__i);
22593e519524SHoward Hinnant            ++__first;
22603e519524SHoward Hinnant            if (++__i == __last)
22613e519524SHoward Hinnant            {
22623e519524SHoward Hinnant                if (__first == __middle)
22633e519524SHoward Hinnant                    break;
22643e519524SHoward Hinnant                __i = __middle;
22653e519524SHoward Hinnant            }
22663e519524SHoward Hinnant            else if (__first == __middle)
22673e519524SHoward Hinnant                __middle = __i;
22683e519524SHoward Hinnant        }
22693e519524SHoward Hinnant    }
22703e519524SHoward Hinnant    return __r;
22713e519524SHoward Hinnant}
22723e519524SHoward Hinnant
22733e519524SHoward Hinnanttemplate<typename _Integral>
22743e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
22753e519524SHoward Hinnant_Integral
227619b4035fSMarshall Clow__algo_gcd(_Integral __x, _Integral __y)
22773e519524SHoward Hinnant{
22783e519524SHoward Hinnant    do
22793e519524SHoward Hinnant    {
22803e519524SHoward Hinnant        _Integral __t = __x % __y;
22813e519524SHoward Hinnant        __x = __y;
22823e519524SHoward Hinnant        __y = __t;
22833e519524SHoward Hinnant    } while (__y);
22843e519524SHoward Hinnant    return __x;
22853e519524SHoward Hinnant}
22863e519524SHoward Hinnant
22873e519524SHoward Hinnanttemplate<typename _RandomAccessIterator>
22883e519524SHoward Hinnant_RandomAccessIterator
2289aca09de3SHoward Hinnant__rotate_gcd(_RandomAccessIterator __first, _RandomAccessIterator __middle, _RandomAccessIterator __last)
22903e519524SHoward Hinnant{
22913e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
22923e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
22933e519524SHoward Hinnant
22943e519524SHoward Hinnant    const difference_type __m1 = __middle - __first;
22953e519524SHoward Hinnant    const difference_type __m2 = __last - __middle;
22963e519524SHoward Hinnant    if (__m1 == __m2)
22973e519524SHoward Hinnant    {
2298ce48a113SHoward Hinnant        _VSTD::swap_ranges(__first, __middle, __middle);
22993e519524SHoward Hinnant        return __middle;
23003e519524SHoward Hinnant    }
230119b4035fSMarshall Clow    const difference_type __g = _VSTD::__algo_gcd(__m1, __m2);
23023e519524SHoward Hinnant    for (_RandomAccessIterator __p = __first + __g; __p != __first;)
23033e519524SHoward Hinnant    {
2304aca09de3SHoward Hinnant        value_type __t(_VSTD::move(*--__p));
23053e519524SHoward Hinnant        _RandomAccessIterator __p1 = __p;
23063e519524SHoward Hinnant        _RandomAccessIterator __p2 = __p1 + __m1;
23073e519524SHoward Hinnant        do
23083e519524SHoward Hinnant        {
2309aca09de3SHoward Hinnant            *__p1 = _VSTD::move(*__p2);
23103e519524SHoward Hinnant            __p1 = __p2;
23113e519524SHoward Hinnant            const difference_type __d = __last - __p2;
23123e519524SHoward Hinnant            if (__m1 < __d)
23133e519524SHoward Hinnant                __p2 += __m1;
23143e519524SHoward Hinnant            else
23153e519524SHoward Hinnant                __p2 = __first + (__m1 - __d);
23163e519524SHoward Hinnant        } while (__p2 != __p);
2317aca09de3SHoward Hinnant        *__p1 = _VSTD::move(__t);
23183e519524SHoward Hinnant    }
23193e519524SHoward Hinnant    return __first + __m2;
23203e519524SHoward Hinnant}
23213e519524SHoward Hinnant
23223e519524SHoward Hinnanttemplate <class _ForwardIterator>
23233e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
23243e519524SHoward Hinnant_ForwardIterator
2325aca09de3SHoward Hinnant__rotate(_ForwardIterator __first, _ForwardIterator __middle, _ForwardIterator __last,
2326aca09de3SHoward Hinnant         _VSTD::forward_iterator_tag)
2327aca09de3SHoward Hinnant{
2328aca09de3SHoward Hinnant    typedef typename _VSTD::iterator_traits<_ForwardIterator>::value_type value_type;
2329aca09de3SHoward Hinnant    if (_VSTD::is_trivially_move_assignable<value_type>::value)
2330aca09de3SHoward Hinnant    {
2331aca09de3SHoward Hinnant        if (_VSTD::next(__first) == __middle)
2332aca09de3SHoward Hinnant            return _VSTD::__rotate_left(__first, __last);
2333aca09de3SHoward Hinnant    }
2334aca09de3SHoward Hinnant    return _VSTD::__rotate_forward(__first, __middle, __last);
2335aca09de3SHoward Hinnant}
2336aca09de3SHoward Hinnant
2337aca09de3SHoward Hinnanttemplate <class _BidirectionalIterator>
2338aca09de3SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
2339aca09de3SHoward Hinnant_BidirectionalIterator
2340aca09de3SHoward Hinnant__rotate(_BidirectionalIterator __first, _BidirectionalIterator __middle, _BidirectionalIterator __last,
2341aca09de3SHoward Hinnant         _VSTD::bidirectional_iterator_tag)
2342aca09de3SHoward Hinnant{
2343aca09de3SHoward Hinnant    typedef typename _VSTD::iterator_traits<_BidirectionalIterator>::value_type value_type;
2344aca09de3SHoward Hinnant    if (_VSTD::is_trivially_move_assignable<value_type>::value)
2345aca09de3SHoward Hinnant    {
2346aca09de3SHoward Hinnant        if (_VSTD::next(__first) == __middle)
2347aca09de3SHoward Hinnant            return _VSTD::__rotate_left(__first, __last);
2348aca09de3SHoward Hinnant        if (_VSTD::next(__middle) == __last)
2349aca09de3SHoward Hinnant            return _VSTD::__rotate_right(__first, __last);
2350aca09de3SHoward Hinnant    }
2351aca09de3SHoward Hinnant    return _VSTD::__rotate_forward(__first, __middle, __last);
2352aca09de3SHoward Hinnant}
2353aca09de3SHoward Hinnant
2354aca09de3SHoward Hinnanttemplate <class _RandomAccessIterator>
2355aca09de3SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
2356aca09de3SHoward Hinnant_RandomAccessIterator
2357aca09de3SHoward Hinnant__rotate(_RandomAccessIterator __first, _RandomAccessIterator __middle, _RandomAccessIterator __last,
2358aca09de3SHoward Hinnant         _VSTD::random_access_iterator_tag)
2359aca09de3SHoward Hinnant{
2360aca09de3SHoward Hinnant    typedef typename _VSTD::iterator_traits<_RandomAccessIterator>::value_type value_type;
2361aca09de3SHoward Hinnant    if (_VSTD::is_trivially_move_assignable<value_type>::value)
2362aca09de3SHoward Hinnant    {
2363aca09de3SHoward Hinnant        if (_VSTD::next(__first) == __middle)
2364aca09de3SHoward Hinnant            return _VSTD::__rotate_left(__first, __last);
2365aca09de3SHoward Hinnant        if (_VSTD::next(__middle) == __last)
2366aca09de3SHoward Hinnant            return _VSTD::__rotate_right(__first, __last);
2367aca09de3SHoward Hinnant        return _VSTD::__rotate_gcd(__first, __middle, __last);
2368aca09de3SHoward Hinnant    }
2369aca09de3SHoward Hinnant    return _VSTD::__rotate_forward(__first, __middle, __last);
2370aca09de3SHoward Hinnant}
2371aca09de3SHoward Hinnant
2372aca09de3SHoward Hinnanttemplate <class _ForwardIterator>
2373aca09de3SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
2374aca09de3SHoward Hinnant_ForwardIterator
23753e519524SHoward Hinnantrotate(_ForwardIterator __first, _ForwardIterator __middle, _ForwardIterator __last)
23763e519524SHoward Hinnant{
2377aca09de3SHoward Hinnant    if (__first == __middle)
2378aca09de3SHoward Hinnant        return __last;
2379aca09de3SHoward Hinnant    if (__middle == __last)
2380aca09de3SHoward Hinnant        return __first;
2381ce48a113SHoward Hinnant    return _VSTD::__rotate(__first, __middle, __last,
2382aca09de3SHoward Hinnant                           typename _VSTD::iterator_traits<_ForwardIterator>::iterator_category());
23833e519524SHoward Hinnant}
23843e519524SHoward Hinnant
23853e519524SHoward Hinnant// rotate_copy
23863e519524SHoward Hinnant
23873e519524SHoward Hinnanttemplate <class _ForwardIterator, class _OutputIterator>
23883e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
23893e519524SHoward Hinnant_OutputIterator
23903e519524SHoward Hinnantrotate_copy(_ForwardIterator __first, _ForwardIterator __middle, _ForwardIterator __last, _OutputIterator __result)
23913e519524SHoward Hinnant{
2392ce48a113SHoward Hinnant    return _VSTD::copy(__first, __middle, _VSTD::copy(__middle, __last, __result));
23933e519524SHoward Hinnant}
23943e519524SHoward Hinnant
23953e519524SHoward Hinnant// min_element
23963e519524SHoward Hinnant
23973e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Compare>
23989d67c6d5SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
23993e519524SHoward Hinnant_ForwardIterator
24000b0671aeSMarshall Clowmin_element(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp)
24013e519524SHoward Hinnant{
2402a60d7facSEric Fiselier    static_assert(__is_forward_iterator<_ForwardIterator>::value,
2403a60d7facSEric Fiselier        "std::min_element requires a ForwardIterator");
24043e519524SHoward Hinnant    if (__first != __last)
24053e519524SHoward Hinnant    {
24063e519524SHoward Hinnant        _ForwardIterator __i = __first;
24073e519524SHoward Hinnant        while (++__i != __last)
24083e519524SHoward Hinnant            if (__comp(*__i, *__first))
24093e519524SHoward Hinnant                __first = __i;
24103e519524SHoward Hinnant    }
24113e519524SHoward Hinnant    return __first;
24123e519524SHoward Hinnant}
24133e519524SHoward Hinnant
24143e519524SHoward Hinnanttemplate <class _ForwardIterator>
24150b0671aeSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
24163e519524SHoward Hinnant_ForwardIterator
24173e519524SHoward Hinnantmin_element(_ForwardIterator __first, _ForwardIterator __last)
24183e519524SHoward Hinnant{
24190b0671aeSMarshall Clow    return _VSTD::min_element(__first, __last,
24204eb27b79SHoward Hinnant              __less<typename iterator_traits<_ForwardIterator>::value_type>());
24214eb27b79SHoward Hinnant}
24224eb27b79SHoward Hinnant
24234eb27b79SHoward Hinnant// min
24244eb27b79SHoward Hinnant
24254eb27b79SHoward Hinnanttemplate <class _Tp, class _Compare>
24269d67c6d5SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
24274eb27b79SHoward Hinnantconst _Tp&
24284eb27b79SHoward Hinnantmin(const _Tp& __a, const _Tp& __b, _Compare __comp)
24294eb27b79SHoward Hinnant{
24304eb27b79SHoward Hinnant    return __comp(__b, __a) ? __b : __a;
24314eb27b79SHoward Hinnant}
24324eb27b79SHoward Hinnant
24334eb27b79SHoward Hinnanttemplate <class _Tp>
24349d67c6d5SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
24354eb27b79SHoward Hinnantconst _Tp&
24364eb27b79SHoward Hinnantmin(const _Tp& __a, const _Tp& __b)
24374eb27b79SHoward Hinnant{
2438ce48a113SHoward Hinnant    return _VSTD::min(__a, __b, __less<_Tp>());
24394eb27b79SHoward Hinnant}
24404eb27b79SHoward Hinnant
2441ddda456aSEric Fiselier#ifndef _LIBCPP_CXX03_LANG
244254976f26SHoward Hinnant
24434eb27b79SHoward Hinnanttemplate<class _Tp, class _Compare>
24449d67c6d5SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
24454eb27b79SHoward Hinnant_Tp
24464eb27b79SHoward Hinnantmin(initializer_list<_Tp> __t, _Compare __comp)
24474eb27b79SHoward Hinnant{
24480b0671aeSMarshall Clow    return *_VSTD::min_element(__t.begin(), __t.end(), __comp);
24494eb27b79SHoward Hinnant}
24504eb27b79SHoward Hinnant
24514eb27b79SHoward Hinnanttemplate<class _Tp>
24529d67c6d5SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
24534eb27b79SHoward Hinnant_Tp
24544eb27b79SHoward Hinnantmin(initializer_list<_Tp> __t)
24554eb27b79SHoward Hinnant{
24560b0671aeSMarshall Clow    return *_VSTD::min_element(__t.begin(), __t.end(), __less<_Tp>());
24573e519524SHoward Hinnant}
24583e519524SHoward Hinnant
2459ddda456aSEric Fiselier#endif  // _LIBCPP_CXX03_LANG
246054976f26SHoward Hinnant
24613e519524SHoward Hinnant// max_element
24623e519524SHoward Hinnant
24633e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Compare>
24649d67c6d5SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
24653e519524SHoward Hinnant_ForwardIterator
24660b0671aeSMarshall Clowmax_element(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp)
24673e519524SHoward Hinnant{
2468a60d7facSEric Fiselier    static_assert(__is_forward_iterator<_ForwardIterator>::value,
2469a60d7facSEric Fiselier        "std::max_element requires a ForwardIterator");
24703e519524SHoward Hinnant    if (__first != __last)
24713e519524SHoward Hinnant    {
24723e519524SHoward Hinnant        _ForwardIterator __i = __first;
24733e519524SHoward Hinnant        while (++__i != __last)
24743e519524SHoward Hinnant            if (__comp(*__first, *__i))
24753e519524SHoward Hinnant                __first = __i;
24763e519524SHoward Hinnant    }
24773e519524SHoward Hinnant    return __first;
24783e519524SHoward Hinnant}
24793e519524SHoward Hinnant
24809d67c6d5SMarshall Clow
24813e519524SHoward Hinnanttemplate <class _ForwardIterator>
24820b0671aeSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
24833e519524SHoward Hinnant_ForwardIterator
24843e519524SHoward Hinnantmax_element(_ForwardIterator __first, _ForwardIterator __last)
24853e519524SHoward Hinnant{
24860b0671aeSMarshall Clow    return _VSTD::max_element(__first, __last,
24874eb27b79SHoward Hinnant              __less<typename iterator_traits<_ForwardIterator>::value_type>());
24884eb27b79SHoward Hinnant}
24894eb27b79SHoward Hinnant
24904eb27b79SHoward Hinnant// max
24914eb27b79SHoward Hinnant
24924eb27b79SHoward Hinnanttemplate <class _Tp, class _Compare>
24939d67c6d5SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
24944eb27b79SHoward Hinnantconst _Tp&
24954eb27b79SHoward Hinnantmax(const _Tp& __a, const _Tp& __b, _Compare __comp)
24964eb27b79SHoward Hinnant{
24974eb27b79SHoward Hinnant    return __comp(__a, __b) ? __b : __a;
24984eb27b79SHoward Hinnant}
24994eb27b79SHoward Hinnant
25004eb27b79SHoward Hinnanttemplate <class _Tp>
25019d67c6d5SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
25024eb27b79SHoward Hinnantconst _Tp&
25034eb27b79SHoward Hinnantmax(const _Tp& __a, const _Tp& __b)
25044eb27b79SHoward Hinnant{
2505ce48a113SHoward Hinnant    return _VSTD::max(__a, __b, __less<_Tp>());
25064eb27b79SHoward Hinnant}
25074eb27b79SHoward Hinnant
2508ddda456aSEric Fiselier#ifndef _LIBCPP_CXX03_LANG
250954976f26SHoward Hinnant
25104eb27b79SHoward Hinnanttemplate<class _Tp, class _Compare>
25119d67c6d5SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
25124eb27b79SHoward Hinnant_Tp
25134eb27b79SHoward Hinnantmax(initializer_list<_Tp> __t, _Compare __comp)
25144eb27b79SHoward Hinnant{
25150b0671aeSMarshall Clow    return *_VSTD::max_element(__t.begin(), __t.end(), __comp);
25164eb27b79SHoward Hinnant}
25174eb27b79SHoward Hinnant
25184eb27b79SHoward Hinnanttemplate<class _Tp>
25199d67c6d5SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
25204eb27b79SHoward Hinnant_Tp
25214eb27b79SHoward Hinnantmax(initializer_list<_Tp> __t)
25224eb27b79SHoward Hinnant{
25230b0671aeSMarshall Clow    return *_VSTD::max_element(__t.begin(), __t.end(), __less<_Tp>());
25243e519524SHoward Hinnant}
25253e519524SHoward Hinnant
2526ddda456aSEric Fiselier#endif  // _LIBCPP_CXX03_LANG
252754976f26SHoward Hinnant
2528146c14acSMarshall Clow#if _LIBCPP_STD_VER > 14
2529146c14acSMarshall Clow// clamp
2530146c14acSMarshall Clowtemplate<class _Tp, class _Compare>
2531146c14acSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
2532146c14acSMarshall Clowconst _Tp&
2533146c14acSMarshall Clowclamp(const _Tp& __v, const _Tp& __lo, const _Tp& __hi, _Compare __comp)
2534146c14acSMarshall Clow{
2535146c14acSMarshall Clow    _LIBCPP_ASSERT(!__comp(__hi, __lo), "Bad bounds passed to std::clamp");
2536146c14acSMarshall Clow    return __comp(__v, __lo) ? __lo : __comp(__hi, __v) ? __hi : __v;
2537146c14acSMarshall Clow
2538146c14acSMarshall Clow}
2539146c14acSMarshall Clow
2540146c14acSMarshall Clowtemplate<class _Tp>
2541146c14acSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
2542146c14acSMarshall Clowconst _Tp&
2543146c14acSMarshall Clowclamp(const _Tp& __v, const _Tp& __lo, const _Tp& __hi)
2544146c14acSMarshall Clow{
2545146c14acSMarshall Clow    return _VSTD::clamp(__v, __lo, __hi, __less<_Tp>());
2546146c14acSMarshall Clow}
2547146c14acSMarshall Clow#endif
2548146c14acSMarshall Clow
25493e519524SHoward Hinnant// minmax_element
25503e519524SHoward Hinnant
25513e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Compare>
25520b0671aeSMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX11
25533e519524SHoward Hinnantstd::pair<_ForwardIterator, _ForwardIterator>
25543e519524SHoward Hinnantminmax_element(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp)
25553e519524SHoward Hinnant{
2556a60d7facSEric Fiselier  static_assert(__is_forward_iterator<_ForwardIterator>::value,
2557a60d7facSEric Fiselier        "std::minmax_element requires a ForwardIterator");
25583e519524SHoward Hinnant  std::pair<_ForwardIterator, _ForwardIterator> __result(__first, __first);
25593e519524SHoward Hinnant  if (__first != __last)
25603e519524SHoward Hinnant  {
25613e519524SHoward Hinnant      if (++__first != __last)
25623e519524SHoward Hinnant      {
25633e519524SHoward Hinnant          if (__comp(*__first, *__result.first))
25643e519524SHoward Hinnant              __result.first = __first;
25653e519524SHoward Hinnant          else
25663e519524SHoward Hinnant              __result.second = __first;
25673e519524SHoward Hinnant          while (++__first != __last)
25683e519524SHoward Hinnant          {
25693e519524SHoward Hinnant              _ForwardIterator __i = __first;
25703e519524SHoward Hinnant              if (++__first == __last)
25713e519524SHoward Hinnant              {
25723e519524SHoward Hinnant                  if (__comp(*__i, *__result.first))
25733e519524SHoward Hinnant                      __result.first = __i;
25743e519524SHoward Hinnant                  else if (!__comp(*__i, *__result.second))
25753e519524SHoward Hinnant                      __result.second = __i;
25763e519524SHoward Hinnant                  break;
25773e519524SHoward Hinnant              }
25783e519524SHoward Hinnant              else
25793e519524SHoward Hinnant              {
25803e519524SHoward Hinnant                  if (__comp(*__first, *__i))
25813e519524SHoward Hinnant                  {
25823e519524SHoward Hinnant                      if (__comp(*__first, *__result.first))
25833e519524SHoward Hinnant                          __result.first = __first;
25843e519524SHoward Hinnant                      if (!__comp(*__i, *__result.second))
25853e519524SHoward Hinnant                          __result.second = __i;
25863e519524SHoward Hinnant                  }
25873e519524SHoward Hinnant                  else
25883e519524SHoward Hinnant                  {
25893e519524SHoward Hinnant                      if (__comp(*__i, *__result.first))
25903e519524SHoward Hinnant                          __result.first = __i;
25913e519524SHoward Hinnant                      if (!__comp(*__first, *__result.second))
25923e519524SHoward Hinnant                          __result.second = __first;
25933e519524SHoward Hinnant                  }
25943e519524SHoward Hinnant              }
25953e519524SHoward Hinnant          }
25963e519524SHoward Hinnant      }
25973e519524SHoward Hinnant  }
25983e519524SHoward Hinnant  return __result;
25993e519524SHoward Hinnant}
26003e519524SHoward Hinnant
26013e519524SHoward Hinnanttemplate <class _ForwardIterator>
26020b0671aeSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
26033e519524SHoward Hinnantstd::pair<_ForwardIterator, _ForwardIterator>
26043e519524SHoward Hinnantminmax_element(_ForwardIterator __first, _ForwardIterator __last)
26053e519524SHoward Hinnant{
26069d67c6d5SMarshall Clow    return _VSTD::minmax_element(__first, __last,
26079d67c6d5SMarshall Clow              __less<typename iterator_traits<_ForwardIterator>::value_type>());
26083e519524SHoward Hinnant}
26093e519524SHoward Hinnant
26104eb27b79SHoward Hinnant// minmax
26114eb27b79SHoward Hinnant
26124eb27b79SHoward Hinnanttemplate<class _Tp, class _Compare>
26139d67c6d5SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
26144eb27b79SHoward Hinnantpair<const _Tp&, const _Tp&>
26154eb27b79SHoward Hinnantminmax(const _Tp& __a, const _Tp& __b, _Compare __comp)
26164eb27b79SHoward Hinnant{
26174eb27b79SHoward Hinnant    return __comp(__b, __a) ? pair<const _Tp&, const _Tp&>(__b, __a) :
26184eb27b79SHoward Hinnant                              pair<const _Tp&, const _Tp&>(__a, __b);
26194eb27b79SHoward Hinnant}
26204eb27b79SHoward Hinnant
26214eb27b79SHoward Hinnanttemplate<class _Tp>
26229d67c6d5SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
26234eb27b79SHoward Hinnantpair<const _Tp&, const _Tp&>
26244eb27b79SHoward Hinnantminmax(const _Tp& __a, const _Tp& __b)
26254eb27b79SHoward Hinnant{
2626ce48a113SHoward Hinnant    return _VSTD::minmax(__a, __b, __less<_Tp>());
26274eb27b79SHoward Hinnant}
26284eb27b79SHoward Hinnant
2629ddda456aSEric Fiselier#ifndef _LIBCPP_CXX03_LANG
263054976f26SHoward Hinnant
26314eb27b79SHoward Hinnanttemplate<class _Tp, class _Compare>
26329d67c6d5SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
26334eb27b79SHoward Hinnantpair<_Tp, _Tp>
26344eb27b79SHoward Hinnantminmax(initializer_list<_Tp> __t, _Compare __comp)
26354eb27b79SHoward Hinnant{
26369d67c6d5SMarshall Clow    typedef typename initializer_list<_Tp>::const_iterator _Iter;
26379d67c6d5SMarshall Clow    _Iter __first = __t.begin();
26389d67c6d5SMarshall Clow    _Iter __last  = __t.end();
26399d67c6d5SMarshall Clow    std::pair<_Tp, _Tp> __result(*__first, *__first);
26409d67c6d5SMarshall Clow
26419d67c6d5SMarshall Clow    ++__first;
26429d67c6d5SMarshall Clow    if (__t.size() % 2 == 0)
26439d67c6d5SMarshall Clow    {
26449d67c6d5SMarshall Clow        if (__comp(*__first,  __result.first))
26459d67c6d5SMarshall Clow            __result.first  = *__first;
26469d67c6d5SMarshall Clow        else
26479d67c6d5SMarshall Clow            __result.second = *__first;
26489d67c6d5SMarshall Clow        ++__first;
26499d67c6d5SMarshall Clow    }
26509d67c6d5SMarshall Clow
26519d67c6d5SMarshall Clow    while (__first != __last)
26529d67c6d5SMarshall Clow    {
26539d67c6d5SMarshall Clow        _Tp __prev = *__first++;
2654002144f6SMarshall Clow        if (__comp(*__first, __prev)) {
2655002144f6SMarshall Clow            if ( __comp(*__first, __result.first)) __result.first  = *__first;
2656002144f6SMarshall Clow            if (!__comp(__prev, __result.second))  __result.second = __prev;
26579d67c6d5SMarshall Clow            }
26589d67c6d5SMarshall Clow        else {
2659002144f6SMarshall Clow            if ( __comp(__prev, __result.first))    __result.first  = __prev;
2660002144f6SMarshall Clow            if (!__comp(*__first, __result.second)) __result.second = *__first;
26619d67c6d5SMarshall Clow            }
26629d67c6d5SMarshall Clow
26639d67c6d5SMarshall Clow        __first++;
26649d67c6d5SMarshall Clow    }
26659d67c6d5SMarshall Clow    return __result;
26669d67c6d5SMarshall Clow}
26679d67c6d5SMarshall Clow
26689d67c6d5SMarshall Clowtemplate<class _Tp>
26699d67c6d5SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
26709d67c6d5SMarshall Clowpair<_Tp, _Tp>
26719d67c6d5SMarshall Clowminmax(initializer_list<_Tp> __t)
26729d67c6d5SMarshall Clow{
26739d67c6d5SMarshall Clow    return _VSTD::minmax(__t, __less<_Tp>());
26744eb27b79SHoward Hinnant}
26754eb27b79SHoward Hinnant
2676ddda456aSEric Fiselier#endif  // _LIBCPP_CXX03_LANG
267754976f26SHoward Hinnant
26783e519524SHoward Hinnant// random_shuffle
26793e519524SHoward Hinnant
2680f9d540b0SHoward Hinnant// __independent_bits_engine
2681f9d540b0SHoward Hinnant
2682c003db1fSHoward Hinnanttemplate <unsigned long long _Xp, size_t _Rp>
2683f9d540b0SHoward Hinnantstruct __log2_imp
26843e519524SHoward Hinnant{
2685c003db1fSHoward Hinnant    static const size_t value = _Xp & ((unsigned long long)(1) << _Rp) ? _Rp
2686c003db1fSHoward Hinnant                                           : __log2_imp<_Xp, _Rp - 1>::value;
26873e519524SHoward Hinnant};
26883e519524SHoward Hinnant
2689c003db1fSHoward Hinnanttemplate <unsigned long long _Xp>
2690c003db1fSHoward Hinnantstruct __log2_imp<_Xp, 0>
26913e519524SHoward Hinnant{
2692f9d540b0SHoward Hinnant    static const size_t value = 0;
26933e519524SHoward Hinnant};
26943e519524SHoward Hinnant
2695c003db1fSHoward Hinnanttemplate <size_t _Rp>
2696c003db1fSHoward Hinnantstruct __log2_imp<0, _Rp>
26973e519524SHoward Hinnant{
2698c003db1fSHoward Hinnant    static const size_t value = _Rp + 1;
26993e519524SHoward Hinnant};
27003e519524SHoward Hinnant
270189918caaSEric Fiseliertemplate <class _UIntType, _UIntType _Xp>
2702f9d540b0SHoward Hinnantstruct __log2
27033e519524SHoward Hinnant{
2704c003db1fSHoward Hinnant    static const size_t value = __log2_imp<_Xp,
270589918caaSEric Fiselier                                         sizeof(_UIntType) * __CHAR_BIT__ - 1>::value;
27063e519524SHoward Hinnant};
27073e519524SHoward Hinnant
2708f9d540b0SHoward Hinnanttemplate<class _Engine, class _UIntType>
2709f9d540b0SHoward Hinnantclass __independent_bits_engine
27103e519524SHoward Hinnant{
2711f9d540b0SHoward Hinnantpublic:
2712f9d540b0SHoward Hinnant    // types
2713f9d540b0SHoward Hinnant    typedef _UIntType result_type;
2714f9d540b0SHoward Hinnant
2715f9d540b0SHoward Hinnantprivate:
2716f9d540b0SHoward Hinnant    typedef typename _Engine::result_type _Engine_result_type;
2717f9d540b0SHoward Hinnant    typedef typename conditional
2718f9d540b0SHoward Hinnant        <
2719f9d540b0SHoward Hinnant            sizeof(_Engine_result_type) <= sizeof(result_type),
2720f9d540b0SHoward Hinnant                result_type,
2721f9d540b0SHoward Hinnant                _Engine_result_type
2722f9d540b0SHoward Hinnant        >::type _Working_result_type;
2723f9d540b0SHoward Hinnant
2724f9d540b0SHoward Hinnant    _Engine& __e_;
2725f9d540b0SHoward Hinnant    size_t __w_;
2726f9d540b0SHoward Hinnant    size_t __w0_;
2727f9d540b0SHoward Hinnant    size_t __n_;
2728f9d540b0SHoward Hinnant    size_t __n0_;
2729f9d540b0SHoward Hinnant    _Working_result_type __y0_;
2730f9d540b0SHoward Hinnant    _Working_result_type __y1_;
2731f9d540b0SHoward Hinnant    _Engine_result_type __mask0_;
2732f9d540b0SHoward Hinnant    _Engine_result_type __mask1_;
2733f9d540b0SHoward Hinnant
2734ddda456aSEric Fiselier#ifdef _LIBCPP_CXX03_LANG
2735c003db1fSHoward Hinnant    static const _Working_result_type _Rp = _Engine::_Max - _Engine::_Min
2736f9d540b0SHoward Hinnant                                          + _Working_result_type(1);
2737e386b7b3SHoward Hinnant#else
2738e386b7b3SHoward Hinnant    static _LIBCPP_CONSTEXPR const _Working_result_type _Rp = _Engine::max() - _Engine::min()
2739e386b7b3SHoward Hinnant                                                      + _Working_result_type(1);
2740e386b7b3SHoward Hinnant#endif
2741e386b7b3SHoward Hinnant    static _LIBCPP_CONSTEXPR const size_t __m = __log2<_Working_result_type, _Rp>::value;
2742e386b7b3SHoward Hinnant    static _LIBCPP_CONSTEXPR const size_t _WDt = numeric_limits<_Working_result_type>::digits;
2743e386b7b3SHoward Hinnant    static _LIBCPP_CONSTEXPR const size_t _EDt = numeric_limits<_Engine_result_type>::digits;
2744f9d540b0SHoward Hinnant
2745f9d540b0SHoward Hinnantpublic:
2746f9d540b0SHoward Hinnant    // constructors and seeding functions
2747f9d540b0SHoward Hinnant    __independent_bits_engine(_Engine& __e, size_t __w);
2748f9d540b0SHoward Hinnant
2749f9d540b0SHoward Hinnant    // generating functions
2750c003db1fSHoward Hinnant    result_type operator()() {return __eval(integral_constant<bool, _Rp != 0>());}
2751f9d540b0SHoward Hinnant
2752f9d540b0SHoward Hinnantprivate:
275308bba64aSMarshall Clow    result_type __eval(false_type);
275408bba64aSMarshall Clow    result_type __eval(true_type);
2755f9d540b0SHoward Hinnant};
2756f9d540b0SHoward Hinnant
2757f9d540b0SHoward Hinnanttemplate<class _Engine, class _UIntType>
2758f9d540b0SHoward Hinnant__independent_bits_engine<_Engine, _UIntType>
2759f9d540b0SHoward Hinnant    ::__independent_bits_engine(_Engine& __e, size_t __w)
2760f9d540b0SHoward Hinnant        : __e_(__e),
2761f9d540b0SHoward Hinnant          __w_(__w)
2762f9d540b0SHoward Hinnant{
2763f9d540b0SHoward Hinnant    __n_ = __w_ / __m + (__w_ % __m != 0);
2764f9d540b0SHoward Hinnant    __w0_ = __w_ / __n_;
2765c003db1fSHoward Hinnant    if (_Rp == 0)
2766c003db1fSHoward Hinnant        __y0_ = _Rp;
2767f9d540b0SHoward Hinnant    else if (__w0_ < _WDt)
2768c003db1fSHoward Hinnant        __y0_ = (_Rp >> __w0_) << __w0_;
2769f9d540b0SHoward Hinnant    else
2770f9d540b0SHoward Hinnant        __y0_ = 0;
2771c003db1fSHoward Hinnant    if (_Rp - __y0_ > __y0_ / __n_)
2772f9d540b0SHoward Hinnant    {
2773f9d540b0SHoward Hinnant        ++__n_;
2774f9d540b0SHoward Hinnant        __w0_ = __w_ / __n_;
2775f9d540b0SHoward Hinnant        if (__w0_ < _WDt)
2776c003db1fSHoward Hinnant            __y0_ = (_Rp >> __w0_) << __w0_;
2777f9d540b0SHoward Hinnant        else
2778f9d540b0SHoward Hinnant            __y0_ = 0;
2779f9d540b0SHoward Hinnant    }
2780f9d540b0SHoward Hinnant    __n0_ = __n_ - __w_ % __n_;
2781f9d540b0SHoward Hinnant    if (__w0_ < _WDt - 1)
2782c003db1fSHoward Hinnant        __y1_ = (_Rp >> (__w0_ + 1)) << (__w0_ + 1);
2783f9d540b0SHoward Hinnant    else
2784f9d540b0SHoward Hinnant        __y1_ = 0;
2785f9d540b0SHoward Hinnant    __mask0_ = __w0_ > 0 ? _Engine_result_type(~0) >> (_EDt - __w0_) :
2786f9d540b0SHoward Hinnant                          _Engine_result_type(0);
2787f9d540b0SHoward Hinnant    __mask1_ = __w0_ < _EDt - 1 ?
2788f9d540b0SHoward Hinnant                               _Engine_result_type(~0) >> (_EDt - (__w0_ + 1)) :
2789f9d540b0SHoward Hinnant                               _Engine_result_type(~0);
27903e519524SHoward Hinnant}
27913e519524SHoward Hinnant
2792f9d540b0SHoward Hinnanttemplate<class _Engine, class _UIntType>
2793f9d540b0SHoward Hinnantinline
2794f9d540b0SHoward Hinnant_UIntType
279508bba64aSMarshall Clow__independent_bits_engine<_Engine, _UIntType>::__eval(false_type)
27963e519524SHoward Hinnant{
2797f9d540b0SHoward Hinnant    return static_cast<result_type>(__e_() & __mask0_);
27983e519524SHoward Hinnant}
27993e519524SHoward Hinnant
2800f9d540b0SHoward Hinnanttemplate<class _Engine, class _UIntType>
2801f9d540b0SHoward Hinnant_UIntType
280208bba64aSMarshall Clow__independent_bits_engine<_Engine, _UIntType>::__eval(true_type)
28033e519524SHoward Hinnant{
28045beb2c3aSMarshall Clow    const size_t _WRt = numeric_limits<result_type>::digits;
2805c003db1fSHoward Hinnant    result_type _Sp = 0;
2806f9d540b0SHoward Hinnant    for (size_t __k = 0; __k < __n0_; ++__k)
2807f9d540b0SHoward Hinnant    {
2808f9d540b0SHoward Hinnant        _Engine_result_type __u;
28093e519524SHoward Hinnant        do
2810f9d540b0SHoward Hinnant        {
2811f9d540b0SHoward Hinnant            __u = __e_() - _Engine::min();
2812f9d540b0SHoward Hinnant        } while (__u >= __y0_);
28135beb2c3aSMarshall Clow        if (__w0_ < _WRt)
2814c003db1fSHoward Hinnant            _Sp <<= __w0_;
2815f9d540b0SHoward Hinnant        else
2816c003db1fSHoward Hinnant            _Sp = 0;
2817c003db1fSHoward Hinnant        _Sp += __u & __mask0_;
2818f9d540b0SHoward Hinnant    }
2819f9d540b0SHoward Hinnant    for (size_t __k = __n0_; __k < __n_; ++__k)
2820f9d540b0SHoward Hinnant    {
2821f9d540b0SHoward Hinnant        _Engine_result_type __u;
2822f9d540b0SHoward Hinnant        do
2823f9d540b0SHoward Hinnant        {
2824f9d540b0SHoward Hinnant            __u = __e_() - _Engine::min();
2825f9d540b0SHoward Hinnant        } while (__u >= __y1_);
28265beb2c3aSMarshall Clow        if (__w0_ < _WRt - 1)
2827c003db1fSHoward Hinnant            _Sp <<= __w0_ + 1;
2828f9d540b0SHoward Hinnant        else
2829c003db1fSHoward Hinnant            _Sp = 0;
2830c003db1fSHoward Hinnant        _Sp += __u & __mask1_;
2831f9d540b0SHoward Hinnant    }
2832c003db1fSHoward Hinnant    return _Sp;
28333e519524SHoward Hinnant}
28343e519524SHoward Hinnant
2835f9d540b0SHoward Hinnant// uniform_int_distribution
28363e519524SHoward Hinnant
2837f9d540b0SHoward Hinnanttemplate<class _IntType = int>
2838f9d540b0SHoward Hinnantclass uniform_int_distribution
28393e519524SHoward Hinnant{
2840f9d540b0SHoward Hinnantpublic:
2841f9d540b0SHoward Hinnant    // types
2842f9d540b0SHoward Hinnant    typedef _IntType result_type;
2843f9d540b0SHoward Hinnant
2844f9d540b0SHoward Hinnant    class param_type
2845f9d540b0SHoward Hinnant    {
2846f9d540b0SHoward Hinnant        result_type __a_;
2847f9d540b0SHoward Hinnant        result_type __b_;
2848f9d540b0SHoward Hinnant    public:
2849f9d540b0SHoward Hinnant        typedef uniform_int_distribution distribution_type;
2850f9d540b0SHoward Hinnant
2851f9d540b0SHoward Hinnant        explicit param_type(result_type __a = 0,
2852f9d540b0SHoward Hinnant                            result_type __b = numeric_limits<result_type>::max())
2853f9d540b0SHoward Hinnant            : __a_(__a), __b_(__b) {}
2854f9d540b0SHoward Hinnant
2855f9d540b0SHoward Hinnant        result_type a() const {return __a_;}
2856f9d540b0SHoward Hinnant        result_type b() const {return __b_;}
2857f9d540b0SHoward Hinnant
2858f9d540b0SHoward Hinnant        friend bool operator==(const param_type& __x, const param_type& __y)
2859f9d540b0SHoward Hinnant            {return __x.__a_ == __y.__a_ && __x.__b_ == __y.__b_;}
2860f9d540b0SHoward Hinnant        friend bool operator!=(const param_type& __x, const param_type& __y)
2861f9d540b0SHoward Hinnant            {return !(__x == __y);}
28623e519524SHoward Hinnant    };
28633e519524SHoward Hinnant
2864f9d540b0SHoward Hinnantprivate:
2865f9d540b0SHoward Hinnant    param_type __p_;
28663e519524SHoward Hinnant
2867f9d540b0SHoward Hinnantpublic:
2868f9d540b0SHoward Hinnant    // constructors and reset functions
2869f9d540b0SHoward Hinnant    explicit uniform_int_distribution(result_type __a = 0,
2870f9d540b0SHoward Hinnant                                      result_type __b = numeric_limits<result_type>::max())
2871f9d540b0SHoward Hinnant        : __p_(param_type(__a, __b)) {}
2872f9d540b0SHoward Hinnant    explicit uniform_int_distribution(const param_type& __p) : __p_(__p) {}
2873f9d540b0SHoward Hinnant    void reset() {}
2874f9d540b0SHoward Hinnant
2875f9d540b0SHoward Hinnant    // generating functions
2876f9d540b0SHoward Hinnant    template<class _URNG> result_type operator()(_URNG& __g)
2877f9d540b0SHoward Hinnant        {return (*this)(__g, __p_);}
2878f9d540b0SHoward Hinnant    template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
2879f9d540b0SHoward Hinnant
2880f9d540b0SHoward Hinnant    // property functions
2881f9d540b0SHoward Hinnant    result_type a() const {return __p_.a();}
2882f9d540b0SHoward Hinnant    result_type b() const {return __p_.b();}
2883f9d540b0SHoward Hinnant
2884f9d540b0SHoward Hinnant    param_type param() const {return __p_;}
2885f9d540b0SHoward Hinnant    void param(const param_type& __p) {__p_ = __p;}
2886f9d540b0SHoward Hinnant
2887f9d540b0SHoward Hinnant    result_type min() const {return a();}
2888f9d540b0SHoward Hinnant    result_type max() const {return b();}
2889f9d540b0SHoward Hinnant
2890f9d540b0SHoward Hinnant    friend bool operator==(const uniform_int_distribution& __x,
2891f9d540b0SHoward Hinnant                           const uniform_int_distribution& __y)
2892f9d540b0SHoward Hinnant        {return __x.__p_ == __y.__p_;}
2893f9d540b0SHoward Hinnant    friend bool operator!=(const uniform_int_distribution& __x,
2894f9d540b0SHoward Hinnant                           const uniform_int_distribution& __y)
2895f9d540b0SHoward Hinnant            {return !(__x == __y);}
28963e519524SHoward Hinnant};
28973e519524SHoward Hinnant
2898f9d540b0SHoward Hinnanttemplate<class _IntType>
2899f9d540b0SHoward Hinnanttemplate<class _URNG>
2900f9d540b0SHoward Hinnanttypename uniform_int_distribution<_IntType>::result_type
2901f9d540b0SHoward Hinnantuniform_int_distribution<_IntType>::operator()(_URNG& __g, const param_type& __p)
29023e519524SHoward Hinnant{
2903f9d540b0SHoward Hinnant    typedef typename conditional<sizeof(result_type) <= sizeof(uint32_t),
2904f9d540b0SHoward Hinnant                                            uint32_t, uint64_t>::type _UIntType;
2905c003db1fSHoward Hinnant    const _UIntType _Rp = __p.b() - __p.a() + _UIntType(1);
2906c003db1fSHoward Hinnant    if (_Rp == 1)
2907f9d540b0SHoward Hinnant        return __p.a();
2908f9d540b0SHoward Hinnant    const size_t _Dt = numeric_limits<_UIntType>::digits;
2909f9d540b0SHoward Hinnant    typedef __independent_bits_engine<_URNG, _UIntType> _Eng;
2910c003db1fSHoward Hinnant    if (_Rp == 0)
2911f9d540b0SHoward Hinnant        return static_cast<result_type>(_Eng(__g, _Dt)());
2912c003db1fSHoward Hinnant    size_t __w = _Dt - __clz(_Rp) - 1;
2913a6438ca1SMarshall Clow    if ((_Rp & (std::numeric_limits<_UIntType>::max() >> (_Dt - __w))) != 0)
2914f9d540b0SHoward Hinnant        ++__w;
2915f9d540b0SHoward Hinnant    _Eng __e(__g, __w);
2916f9d540b0SHoward Hinnant    _UIntType __u;
2917f9d540b0SHoward Hinnant    do
29183e519524SHoward Hinnant    {
2919f9d540b0SHoward Hinnant        __u = __e();
2920c003db1fSHoward Hinnant    } while (__u >= _Rp);
2921f9d540b0SHoward Hinnant    return static_cast<result_type>(__u + __p.a());
29223e519524SHoward Hinnant}
2923f9d540b0SHoward Hinnant
292466f1ec46SEric Fiselier#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_RANDOM_SHUFFLE) \
292566f1ec46SEric Fiselier  || defined(_LIBCPP_BUILDING_LIBRARY)
2926f0544c20SHoward Hinnantclass _LIBCPP_TYPE_VIS __rs_default;
2927f9d540b0SHoward Hinnant
2928f0544c20SHoward Hinnant_LIBCPP_FUNC_VIS __rs_default __rs_get();
2929f9d540b0SHoward Hinnant
2930f0544c20SHoward Hinnantclass _LIBCPP_TYPE_VIS __rs_default
29313e519524SHoward Hinnant{
2932f9d540b0SHoward Hinnant    static unsigned __c_;
2933f9d540b0SHoward Hinnant
2934f9d540b0SHoward Hinnant    __rs_default();
2935f9d540b0SHoward Hinnantpublic:
2936b6e5f854SMarshall Clow    typedef uint_fast32_t result_type;
2937f9d540b0SHoward Hinnant
2938f9d540b0SHoward Hinnant    static const result_type _Min = 0;
2939f9d540b0SHoward Hinnant    static const result_type _Max = 0xFFFFFFFF;
2940f9d540b0SHoward Hinnant
2941f9d540b0SHoward Hinnant    __rs_default(const __rs_default&);
2942f9d540b0SHoward Hinnant    ~__rs_default();
2943f9d540b0SHoward Hinnant
2944f9d540b0SHoward Hinnant    result_type operator()();
2945f9d540b0SHoward Hinnant
2946788c9979SHoward Hinnant    static _LIBCPP_CONSTEXPR result_type min() {return _Min;}
2947788c9979SHoward Hinnant    static _LIBCPP_CONSTEXPR result_type max() {return _Max;}
2948f9d540b0SHoward Hinnant
2949f0544c20SHoward Hinnant    friend _LIBCPP_FUNC_VIS __rs_default __rs_get();
2950f9d540b0SHoward Hinnant};
2951f9d540b0SHoward Hinnant
2952f0544c20SHoward Hinnant_LIBCPP_FUNC_VIS __rs_default __rs_get();
29533e519524SHoward Hinnant
29543e519524SHoward Hinnanttemplate <class _RandomAccessIterator>
29553e519524SHoward Hinnantvoid
29563e519524SHoward Hinnantrandom_shuffle(_RandomAccessIterator __first, _RandomAccessIterator __last)
29573e519524SHoward Hinnant{
29583e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
2959c003db1fSHoward Hinnant    typedef uniform_int_distribution<ptrdiff_t> _Dp;
2960c003db1fSHoward Hinnant    typedef typename _Dp::param_type _Pp;
29613e519524SHoward Hinnant    difference_type __d = __last - __first;
29623e519524SHoward Hinnant    if (__d > 1)
29633e519524SHoward Hinnant    {
2964c003db1fSHoward Hinnant        _Dp __uid;
2965f9d540b0SHoward Hinnant        __rs_default __g = __rs_get();
2966f9d540b0SHoward Hinnant        for (--__last, --__d; __first < __last; ++__first, --__d)
2967007b26beSHoward Hinnant        {
2968c003db1fSHoward Hinnant            difference_type __i = __uid(__g, _Pp(0, __d));
2969007b26beSHoward Hinnant            if (__i != difference_type(0))
2970007b26beSHoward Hinnant                swap(*__first, *(__first + __i));
2971007b26beSHoward Hinnant        }
29723e519524SHoward Hinnant    }
29733e519524SHoward Hinnant}
29743e519524SHoward Hinnant
29753e519524SHoward Hinnanttemplate <class _RandomAccessIterator, class _RandomNumberGenerator>
29763e519524SHoward Hinnantvoid
29773e519524SHoward Hinnantrandom_shuffle(_RandomAccessIterator __first, _RandomAccessIterator __last,
2978ddda456aSEric Fiselier#ifndef _LIBCPP_CXX03_LANG
29793e519524SHoward Hinnant               _RandomNumberGenerator&& __rand)
29803e519524SHoward Hinnant#else
29813e519524SHoward Hinnant               _RandomNumberGenerator& __rand)
29823e519524SHoward Hinnant#endif
29833e519524SHoward Hinnant{
29843e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
29853e519524SHoward Hinnant    difference_type __d = __last - __first;
29863e519524SHoward Hinnant    if (__d > 1)
29873e519524SHoward Hinnant    {
29883e519524SHoward Hinnant        for (--__last; __first < __last; ++__first, --__d)
2989007b26beSHoward Hinnant        {
2990007b26beSHoward Hinnant            difference_type __i = __rand(__d);
2991e9cc5451SMarshall Clow            if (__i != difference_type(0))
2992007b26beSHoward Hinnant	            swap(*__first, *(__first + __i));
2993007b26beSHoward Hinnant        }
29943e519524SHoward Hinnant    }
29953e519524SHoward Hinnant}
29960f37a410SMarshall Clow#endif
29973e519524SHoward Hinnant
2998e7154709SEric Fiseliertemplate <class _PopulationIterator, class _SampleIterator, class _Distance,
2999e7154709SEric Fiselier          class _UniformRandomNumberGenerator>
3000e7154709SEric Fiselier_LIBCPP_INLINE_VISIBILITY
3001e7154709SEric Fiselier_SampleIterator __sample(_PopulationIterator __first,
300242bfedd9SAlexander Richardson                         _PopulationIterator __last, _SampleIterator __output_iter,
3003e7154709SEric Fiselier                         _Distance __n,
3004e7154709SEric Fiselier                         _UniformRandomNumberGenerator & __g,
3005e7154709SEric Fiselier                         input_iterator_tag) {
3006e7154709SEric Fiselier
3007e7154709SEric Fiselier  _Distance __k = 0;
3008e7154709SEric Fiselier  for (; __first != __last && __k < __n; ++__first, (void)++__k)
300942bfedd9SAlexander Richardson    __output_iter[__k] = *__first;
3010e7154709SEric Fiselier  _Distance __sz = __k;
3011e7154709SEric Fiselier  for (; __first != __last; ++__first, (void)++__k) {
3012e7154709SEric Fiselier    _Distance __r = _VSTD::uniform_int_distribution<_Distance>(0, __k)(__g);
3013e7154709SEric Fiselier    if (__r < __sz)
301442bfedd9SAlexander Richardson      __output_iter[__r] = *__first;
3015e7154709SEric Fiselier  }
301642bfedd9SAlexander Richardson  return __output_iter + _VSTD::min(__n, __k);
3017e7154709SEric Fiselier}
3018e7154709SEric Fiselier
3019e7154709SEric Fiseliertemplate <class _PopulationIterator, class _SampleIterator, class _Distance,
3020e7154709SEric Fiselier          class _UniformRandomNumberGenerator>
3021e7154709SEric Fiselier_LIBCPP_INLINE_VISIBILITY
3022e7154709SEric Fiselier_SampleIterator __sample(_PopulationIterator __first,
302342bfedd9SAlexander Richardson                         _PopulationIterator __last, _SampleIterator __output_iter,
3024e7154709SEric Fiselier                         _Distance __n,
3025e7154709SEric Fiselier                         _UniformRandomNumberGenerator& __g,
3026e7154709SEric Fiselier                         forward_iterator_tag) {
3027e7154709SEric Fiselier  _Distance __unsampled_sz = _VSTD::distance(__first, __last);
3028e7154709SEric Fiselier  for (__n = _VSTD::min(__n, __unsampled_sz); __n != 0; ++__first) {
3029e7154709SEric Fiselier    _Distance __r =
3030e7154709SEric Fiselier        _VSTD::uniform_int_distribution<_Distance>(0, --__unsampled_sz)(__g);
3031e7154709SEric Fiselier    if (__r < __n) {
303242bfedd9SAlexander Richardson      *__output_iter++ = *__first;
3033e7154709SEric Fiselier      --__n;
3034e7154709SEric Fiselier    }
3035e7154709SEric Fiselier  }
303642bfedd9SAlexander Richardson  return __output_iter;
3037e7154709SEric Fiselier}
3038e7154709SEric Fiselier
3039e7154709SEric Fiseliertemplate <class _PopulationIterator, class _SampleIterator, class _Distance,
3040e7154709SEric Fiselier          class _UniformRandomNumberGenerator>
3041e7154709SEric Fiselier_LIBCPP_INLINE_VISIBILITY
3042e7154709SEric Fiselier_SampleIterator __sample(_PopulationIterator __first,
304342bfedd9SAlexander Richardson                         _PopulationIterator __last, _SampleIterator __output_iter,
3044e7154709SEric Fiselier                         _Distance __n, _UniformRandomNumberGenerator& __g) {
3045e7154709SEric Fiselier  typedef typename iterator_traits<_PopulationIterator>::iterator_category
3046e7154709SEric Fiselier        _PopCategory;
3047e7154709SEric Fiselier  typedef typename iterator_traits<_PopulationIterator>::difference_type
3048e7154709SEric Fiselier        _Difference;
3049e7154709SEric Fiselier  static_assert(__is_forward_iterator<_PopulationIterator>::value ||
3050e7154709SEric Fiselier                __is_random_access_iterator<_SampleIterator>::value,
3051e7154709SEric Fiselier                "SampleIterator must meet the requirements of RandomAccessIterator");
3052e7154709SEric Fiselier  typedef typename common_type<_Distance, _Difference>::type _CommonType;
3053e7154709SEric Fiselier  _LIBCPP_ASSERT(__n >= 0, "N must be a positive number.");
3054e7154709SEric Fiselier  return _VSTD::__sample(
305542bfedd9SAlexander Richardson      __first, __last, __output_iter, _CommonType(__n),
3056e7154709SEric Fiselier      __g, _PopCategory());
3057e7154709SEric Fiselier}
3058e7154709SEric Fiselier
3059e7154709SEric Fiselier#if _LIBCPP_STD_VER > 14
3060e7154709SEric Fiseliertemplate <class _PopulationIterator, class _SampleIterator, class _Distance,
3061e7154709SEric Fiselier          class _UniformRandomNumberGenerator>
3062e7154709SEric Fiselierinline _LIBCPP_INLINE_VISIBILITY
3063e7154709SEric Fiselier_SampleIterator sample(_PopulationIterator __first,
306442bfedd9SAlexander Richardson                       _PopulationIterator __last, _SampleIterator __output_iter,
3065e7154709SEric Fiselier                       _Distance __n, _UniformRandomNumberGenerator&& __g) {
306642bfedd9SAlexander Richardson    return _VSTD::__sample(__first, __last, __output_iter, __n, __g);
3067e7154709SEric Fiselier}
3068e7154709SEric Fiselier#endif // _LIBCPP_STD_VER > 14
3069e7154709SEric Fiselier
3070f9d540b0SHoward Hinnanttemplate<class _RandomAccessIterator, class _UniformRandomNumberGenerator>
3071f9d540b0SHoward Hinnant    void shuffle(_RandomAccessIterator __first, _RandomAccessIterator __last,
3072ddda456aSEric Fiselier#ifndef _LIBCPP_CXX03_LANG
3073fb340102SHoward Hinnant                 _UniformRandomNumberGenerator&& __g)
3074fb340102SHoward Hinnant#else
3075f9d540b0SHoward Hinnant                 _UniformRandomNumberGenerator& __g)
3076fb340102SHoward Hinnant#endif
3077f9d540b0SHoward Hinnant{
3078f9d540b0SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
3079c003db1fSHoward Hinnant    typedef uniform_int_distribution<ptrdiff_t> _Dp;
3080c003db1fSHoward Hinnant    typedef typename _Dp::param_type _Pp;
3081f9d540b0SHoward Hinnant    difference_type __d = __last - __first;
3082f9d540b0SHoward Hinnant    if (__d > 1)
3083f9d540b0SHoward Hinnant    {
3084c003db1fSHoward Hinnant        _Dp __uid;
3085f9d540b0SHoward Hinnant        for (--__last, --__d; __first < __last; ++__first, --__d)
3086007b26beSHoward Hinnant        {
3087c003db1fSHoward Hinnant            difference_type __i = __uid(__g, _Pp(0, __d));
3088007b26beSHoward Hinnant            if (__i != difference_type(0))
3089007b26beSHoward Hinnant                swap(*__first, *(__first + __i));
3090007b26beSHoward Hinnant        }
3091f9d540b0SHoward Hinnant    }
3092f9d540b0SHoward Hinnant}
3093f9d540b0SHoward Hinnant
30943e519524SHoward Hinnanttemplate <class _InputIterator, class _Predicate>
309549c7643cSMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
30963e519524SHoward Hinnantis_partitioned(_InputIterator __first, _InputIterator __last, _Predicate __pred)
30973e519524SHoward Hinnant{
30983e519524SHoward Hinnant    for (; __first != __last; ++__first)
30993e519524SHoward Hinnant        if (!__pred(*__first))
31003e519524SHoward Hinnant            break;
3101b9595b79SMarshall Clow    if ( __first == __last )
3102b9595b79SMarshall Clow        return true;
3103b9595b79SMarshall Clow    ++__first;
31043e519524SHoward Hinnant    for (; __first != __last; ++__first)
31053e519524SHoward Hinnant        if (__pred(*__first))
31063e519524SHoward Hinnant            return false;
31073e519524SHoward Hinnant    return true;
31083e519524SHoward Hinnant}
31093e519524SHoward Hinnant
31103e519524SHoward Hinnant// partition
31113e519524SHoward Hinnant
31123e519524SHoward Hinnanttemplate <class _Predicate, class _ForwardIterator>
31133e519524SHoward Hinnant_ForwardIterator
31143e519524SHoward Hinnant__partition(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred, forward_iterator_tag)
31153e519524SHoward Hinnant{
31163e519524SHoward Hinnant    while (true)
31173e519524SHoward Hinnant    {
31183e519524SHoward Hinnant        if (__first == __last)
31193e519524SHoward Hinnant            return __first;
31203e519524SHoward Hinnant        if (!__pred(*__first))
31213e519524SHoward Hinnant            break;
31223e519524SHoward Hinnant        ++__first;
31233e519524SHoward Hinnant    }
31243e519524SHoward Hinnant    for (_ForwardIterator __p = __first; ++__p != __last;)
31253e519524SHoward Hinnant    {
31263e519524SHoward Hinnant        if (__pred(*__p))
31273e519524SHoward Hinnant        {
31283e519524SHoward Hinnant            swap(*__first, *__p);
31293e519524SHoward Hinnant            ++__first;
31303e519524SHoward Hinnant        }
31313e519524SHoward Hinnant    }
31323e519524SHoward Hinnant    return __first;
31333e519524SHoward Hinnant}
31343e519524SHoward Hinnant
31353e519524SHoward Hinnanttemplate <class _Predicate, class _BidirectionalIterator>
31363e519524SHoward Hinnant_BidirectionalIterator
31373e519524SHoward Hinnant__partition(_BidirectionalIterator __first, _BidirectionalIterator __last, _Predicate __pred,
31383e519524SHoward Hinnant            bidirectional_iterator_tag)
31393e519524SHoward Hinnant{
31403e519524SHoward Hinnant    while (true)
31413e519524SHoward Hinnant    {
31423e519524SHoward Hinnant        while (true)
31433e519524SHoward Hinnant        {
31443e519524SHoward Hinnant            if (__first == __last)
31453e519524SHoward Hinnant                return __first;
31463e519524SHoward Hinnant            if (!__pred(*__first))
31473e519524SHoward Hinnant                break;
31483e519524SHoward Hinnant            ++__first;
31493e519524SHoward Hinnant        }
31503e519524SHoward Hinnant        do
31513e519524SHoward Hinnant        {
31523e519524SHoward Hinnant            if (__first == --__last)
31533e519524SHoward Hinnant                return __first;
31543e519524SHoward Hinnant        } while (!__pred(*__last));
31553e519524SHoward Hinnant        swap(*__first, *__last);
31563e519524SHoward Hinnant        ++__first;
31573e519524SHoward Hinnant    }
31583e519524SHoward Hinnant}
31593e519524SHoward Hinnant
31603e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Predicate>
31613e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
31623e519524SHoward Hinnant_ForwardIterator
31633e519524SHoward Hinnantpartition(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred)
31643e519524SHoward Hinnant{
3165ce48a113SHoward Hinnant    return _VSTD::__partition<typename add_lvalue_reference<_Predicate>::type>
31663e519524SHoward Hinnant                            (__first, __last, __pred, typename iterator_traits<_ForwardIterator>::iterator_category());
31673e519524SHoward Hinnant}
31683e519524SHoward Hinnant
31693e519524SHoward Hinnant// partition_copy
31703e519524SHoward Hinnant
31713e519524SHoward Hinnanttemplate <class _InputIterator, class _OutputIterator1,
31723e519524SHoward Hinnant          class _OutputIterator2, class _Predicate>
31731b9a4ffdSMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 pair<_OutputIterator1, _OutputIterator2>
31743e519524SHoward Hinnantpartition_copy(_InputIterator __first, _InputIterator __last,
31753e519524SHoward Hinnant               _OutputIterator1 __out_true, _OutputIterator2 __out_false,
31763e519524SHoward Hinnant               _Predicate __pred)
31773e519524SHoward Hinnant{
31783e519524SHoward Hinnant    for (; __first != __last; ++__first)
31793e519524SHoward Hinnant    {
31803e519524SHoward Hinnant        if (__pred(*__first))
31813e519524SHoward Hinnant        {
31823e519524SHoward Hinnant            *__out_true = *__first;
31833e519524SHoward Hinnant            ++__out_true;
31843e519524SHoward Hinnant        }
31853e519524SHoward Hinnant        else
31863e519524SHoward Hinnant        {
31873e519524SHoward Hinnant            *__out_false = *__first;
31883e519524SHoward Hinnant            ++__out_false;
31893e519524SHoward Hinnant        }
31903e519524SHoward Hinnant    }
31913e519524SHoward Hinnant    return pair<_OutputIterator1, _OutputIterator2>(__out_true, __out_false);
31923e519524SHoward Hinnant}
31933e519524SHoward Hinnant
31943e519524SHoward Hinnant// partition_point
31953e519524SHoward Hinnant
31963e519524SHoward Hinnanttemplate<class _ForwardIterator, class _Predicate>
3197674f9128SMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
31983e519524SHoward Hinnantpartition_point(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred)
31993e519524SHoward Hinnant{
32003e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator>::difference_type difference_type;
3201ce48a113SHoward Hinnant    difference_type __len = _VSTD::distance(__first, __last);
32023e519524SHoward Hinnant    while (__len != 0)
32033e519524SHoward Hinnant    {
32043e519524SHoward Hinnant        difference_type __l2 = __len / 2;
32053e519524SHoward Hinnant        _ForwardIterator __m = __first;
3206ce48a113SHoward Hinnant        _VSTD::advance(__m, __l2);
32073e519524SHoward Hinnant        if (__pred(*__m))
32083e519524SHoward Hinnant        {
32093e519524SHoward Hinnant            __first = ++__m;
32103e519524SHoward Hinnant            __len -= __l2 + 1;
32113e519524SHoward Hinnant        }
32123e519524SHoward Hinnant        else
32133e519524SHoward Hinnant            __len = __l2;
32143e519524SHoward Hinnant    }
32153e519524SHoward Hinnant    return __first;
32163e519524SHoward Hinnant}
32173e519524SHoward Hinnant
32183e519524SHoward Hinnant// stable_partition
32193e519524SHoward Hinnant
32203e519524SHoward Hinnanttemplate <class _Predicate, class _ForwardIterator, class _Distance, class _Pair>
32213e519524SHoward Hinnant_ForwardIterator
32223e519524SHoward Hinnant__stable_partition(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred,
32233e519524SHoward Hinnant                   _Distance __len, _Pair __p, forward_iterator_tag __fit)
32243e519524SHoward Hinnant{
32253e519524SHoward Hinnant    // *__first is known to be false
32263e519524SHoward Hinnant    // __len >= 1
32273e519524SHoward Hinnant    if (__len == 1)
32283e519524SHoward Hinnant        return __first;
32293e519524SHoward Hinnant    if (__len == 2)
32303e519524SHoward Hinnant    {
32313e519524SHoward Hinnant        _ForwardIterator __m = __first;
32323e519524SHoward Hinnant        if (__pred(*++__m))
32333e519524SHoward Hinnant        {
32343e519524SHoward Hinnant            swap(*__first, *__m);
32353e519524SHoward Hinnant            return __m;
32363e519524SHoward Hinnant        }
32373e519524SHoward Hinnant        return __first;
32383e519524SHoward Hinnant    }
32393e519524SHoward Hinnant    if (__len <= __p.second)
32403e519524SHoward Hinnant    {   // The buffer is big enough to use
32413e519524SHoward Hinnant        typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
32423e519524SHoward Hinnant        __destruct_n __d(0);
32433e519524SHoward Hinnant        unique_ptr<value_type, __destruct_n&> __h(__p.first, __d);
32443e519524SHoward Hinnant        // Move the falses into the temporary buffer, and the trues to the front of the line
32453e519524SHoward Hinnant        // Update __first to always point to the end of the trues
32463e519524SHoward Hinnant        value_type* __t = __p.first;
3247ce48a113SHoward Hinnant        ::new(__t) value_type(_VSTD::move(*__first));
32483e519524SHoward Hinnant        __d.__incr((value_type*)0);
32493e519524SHoward Hinnant        ++__t;
32503e519524SHoward Hinnant        _ForwardIterator __i = __first;
32513e519524SHoward Hinnant        while (++__i != __last)
32523e519524SHoward Hinnant        {
32533e519524SHoward Hinnant            if (__pred(*__i))
32543e519524SHoward Hinnant            {
3255ce48a113SHoward Hinnant                *__first = _VSTD::move(*__i);
32563e519524SHoward Hinnant                ++__first;
32573e519524SHoward Hinnant            }
32583e519524SHoward Hinnant            else
32593e519524SHoward Hinnant            {
3260ce48a113SHoward Hinnant                ::new(__t) value_type(_VSTD::move(*__i));
32613e519524SHoward Hinnant                __d.__incr((value_type*)0);
32623e519524SHoward Hinnant                ++__t;
32633e519524SHoward Hinnant            }
32643e519524SHoward Hinnant        }
32653e519524SHoward Hinnant        // All trues now at start of range, all falses in buffer
32663e519524SHoward Hinnant        // Move falses back into range, but don't mess up __first which points to first false
32673e519524SHoward Hinnant        __i = __first;
32683e519524SHoward Hinnant        for (value_type* __t2 = __p.first; __t2 < __t; ++__t2, ++__i)
3269ce48a113SHoward Hinnant            *__i = _VSTD::move(*__t2);
32703e519524SHoward Hinnant        // __h destructs moved-from values out of the temp buffer, but doesn't deallocate buffer
32713e519524SHoward Hinnant        return __first;
32723e519524SHoward Hinnant    }
32733e519524SHoward Hinnant    // Else not enough buffer, do in place
32743e519524SHoward Hinnant    // __len >= 3
32753e519524SHoward Hinnant    _ForwardIterator __m = __first;
32763e519524SHoward Hinnant    _Distance __len2 = __len / 2;  // __len2 >= 2
3277ce48a113SHoward Hinnant    _VSTD::advance(__m, __len2);
32783e519524SHoward Hinnant    // recurse on [__first, __m), *__first know to be false
32793e519524SHoward Hinnant    // F?????????????????
32803e519524SHoward Hinnant    // f       m         l
32813e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Predicate>::type _PredRef;
32823e519524SHoward Hinnant    _ForwardIterator __first_false = __stable_partition<_PredRef>(__first, __m, __pred, __len2, __p, __fit);
32833e519524SHoward Hinnant    // TTTFFFFF??????????
32843e519524SHoward Hinnant    // f  ff   m         l
32853e519524SHoward Hinnant    // recurse on [__m, __last], except increase __m until *(__m) is false, *__last know to be true
32863e519524SHoward Hinnant    _ForwardIterator __m1 = __m;
32873e519524SHoward Hinnant    _ForwardIterator __second_false = __last;
32883e519524SHoward Hinnant    _Distance __len_half = __len - __len2;
32893e519524SHoward Hinnant    while (__pred(*__m1))
32903e519524SHoward Hinnant    {
32913e519524SHoward Hinnant        if (++__m1 == __last)
32923e519524SHoward Hinnant            goto __second_half_done;
32933e519524SHoward Hinnant        --__len_half;
32943e519524SHoward Hinnant    }
32953e519524SHoward Hinnant    // TTTFFFFFTTTF??????
32963e519524SHoward Hinnant    // f  ff   m  m1     l
32973e519524SHoward Hinnant    __second_false = __stable_partition<_PredRef>(__m1, __last, __pred, __len_half, __p, __fit);
32983e519524SHoward Hinnant__second_half_done:
32993e519524SHoward Hinnant    // TTTFFFFFTTTTTFFFFF
33003e519524SHoward Hinnant    // f  ff   m    sf   l
3301ce48a113SHoward Hinnant    return _VSTD::rotate(__first_false, __m, __second_false);
33023e519524SHoward Hinnant    // TTTTTTTTFFFFFFFFFF
33033e519524SHoward Hinnant    //         |
33043e519524SHoward Hinnant}
33053e519524SHoward Hinnant
33063e519524SHoward Hinnantstruct __return_temporary_buffer
33073e519524SHoward Hinnant{
33083e519524SHoward Hinnant    template <class _Tp>
3309ce48a113SHoward Hinnant    _LIBCPP_INLINE_VISIBILITY void operator()(_Tp* __p) const {_VSTD::return_temporary_buffer(__p);}
33103e519524SHoward Hinnant};
33113e519524SHoward Hinnant
33123e519524SHoward Hinnanttemplate <class _Predicate, class _ForwardIterator>
33133e519524SHoward Hinnant_ForwardIterator
33143e519524SHoward Hinnant__stable_partition(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred,
33153e519524SHoward Hinnant                   forward_iterator_tag)
33163e519524SHoward Hinnant{
33173e519524SHoward Hinnant    const unsigned __alloc_limit = 3;  // might want to make this a function of trivial assignment
33183e519524SHoward Hinnant    // Either prove all true and return __first or point to first false
33193e519524SHoward Hinnant    while (true)
33203e519524SHoward Hinnant    {
33213e519524SHoward Hinnant        if (__first == __last)
33223e519524SHoward Hinnant            return __first;
33233e519524SHoward Hinnant        if (!__pred(*__first))
33243e519524SHoward Hinnant            break;
33253e519524SHoward Hinnant        ++__first;
33263e519524SHoward Hinnant    }
33273e519524SHoward Hinnant    // We now have a reduced range [__first, __last)
33283e519524SHoward Hinnant    // *__first is known to be false
33293e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator>::difference_type difference_type;
33303e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
3331ce48a113SHoward Hinnant    difference_type __len = _VSTD::distance(__first, __last);
33323e519524SHoward Hinnant    pair<value_type*, ptrdiff_t> __p(0, 0);
33333e519524SHoward Hinnant    unique_ptr<value_type, __return_temporary_buffer> __h;
33343e519524SHoward Hinnant    if (__len >= __alloc_limit)
33353e519524SHoward Hinnant    {
3336ce48a113SHoward Hinnant        __p = _VSTD::get_temporary_buffer<value_type>(__len);
33373e519524SHoward Hinnant        __h.reset(__p.first);
33383e519524SHoward Hinnant    }
33393e519524SHoward Hinnant    return __stable_partition<typename add_lvalue_reference<_Predicate>::type>
33403e519524SHoward Hinnant                             (__first, __last, __pred, __len, __p, forward_iterator_tag());
33413e519524SHoward Hinnant}
33423e519524SHoward Hinnant
33433e519524SHoward Hinnanttemplate <class _Predicate, class _BidirectionalIterator, class _Distance, class _Pair>
33443e519524SHoward Hinnant_BidirectionalIterator
33453e519524SHoward Hinnant__stable_partition(_BidirectionalIterator __first, _BidirectionalIterator __last, _Predicate __pred,
33463e519524SHoward Hinnant                   _Distance __len, _Pair __p, bidirectional_iterator_tag __bit)
33473e519524SHoward Hinnant{
33483e519524SHoward Hinnant    // *__first is known to be false
33493e519524SHoward Hinnant    // *__last is known to be true
33503e519524SHoward Hinnant    // __len >= 2
33513e519524SHoward Hinnant    if (__len == 2)
33523e519524SHoward Hinnant    {
33533e519524SHoward Hinnant        swap(*__first, *__last);
33543e519524SHoward Hinnant        return __last;
33553e519524SHoward Hinnant    }
33563e519524SHoward Hinnant    if (__len == 3)
33573e519524SHoward Hinnant    {
33583e519524SHoward Hinnant        _BidirectionalIterator __m = __first;
33593e519524SHoward Hinnant        if (__pred(*++__m))
33603e519524SHoward Hinnant        {
33613e519524SHoward Hinnant            swap(*__first, *__m);
33623e519524SHoward Hinnant            swap(*__m, *__last);
33633e519524SHoward Hinnant            return __last;
33643e519524SHoward Hinnant        }
33653e519524SHoward Hinnant        swap(*__m, *__last);
33663e519524SHoward Hinnant        swap(*__first, *__m);
33673e519524SHoward Hinnant        return __m;
33683e519524SHoward Hinnant    }
33693e519524SHoward Hinnant    if (__len <= __p.second)
33703e519524SHoward Hinnant    {   // The buffer is big enough to use
33713e519524SHoward Hinnant        typedef typename iterator_traits<_BidirectionalIterator>::value_type value_type;
33723e519524SHoward Hinnant        __destruct_n __d(0);
33733e519524SHoward Hinnant        unique_ptr<value_type, __destruct_n&> __h(__p.first, __d);
33743e519524SHoward Hinnant        // Move the falses into the temporary buffer, and the trues to the front of the line
33753e519524SHoward Hinnant        // Update __first to always point to the end of the trues
33763e519524SHoward Hinnant        value_type* __t = __p.first;
3377ce48a113SHoward Hinnant        ::new(__t) value_type(_VSTD::move(*__first));
33783e519524SHoward Hinnant        __d.__incr((value_type*)0);
33793e519524SHoward Hinnant        ++__t;
33803e519524SHoward Hinnant        _BidirectionalIterator __i = __first;
33813e519524SHoward Hinnant        while (++__i != __last)
33823e519524SHoward Hinnant        {
33833e519524SHoward Hinnant            if (__pred(*__i))
33843e519524SHoward Hinnant            {
3385ce48a113SHoward Hinnant                *__first = _VSTD::move(*__i);
33863e519524SHoward Hinnant                ++__first;
33873e519524SHoward Hinnant            }
33883e519524SHoward Hinnant            else
33893e519524SHoward Hinnant            {
3390ce48a113SHoward Hinnant                ::new(__t) value_type(_VSTD::move(*__i));
33913e519524SHoward Hinnant                __d.__incr((value_type*)0);
33923e519524SHoward Hinnant                ++__t;
33933e519524SHoward Hinnant            }
33943e519524SHoward Hinnant        }
33953e519524SHoward Hinnant        // move *__last, known to be true
3396ce48a113SHoward Hinnant        *__first = _VSTD::move(*__i);
33973e519524SHoward Hinnant        __i = ++__first;
33983e519524SHoward Hinnant        // All trues now at start of range, all falses in buffer
33993e519524SHoward Hinnant        // Move falses back into range, but don't mess up __first which points to first false
34003e519524SHoward Hinnant        for (value_type* __t2 = __p.first; __t2 < __t; ++__t2, ++__i)
3401ce48a113SHoward Hinnant            *__i = _VSTD::move(*__t2);
34023e519524SHoward Hinnant        // __h destructs moved-from values out of the temp buffer, but doesn't deallocate buffer
34033e519524SHoward Hinnant        return __first;
34043e519524SHoward Hinnant    }
34053e519524SHoward Hinnant    // Else not enough buffer, do in place
34063e519524SHoward Hinnant    // __len >= 4
34073e519524SHoward Hinnant    _BidirectionalIterator __m = __first;
34083e519524SHoward Hinnant    _Distance __len2 = __len / 2;  // __len2 >= 2
3409ce48a113SHoward Hinnant    _VSTD::advance(__m, __len2);
34103e519524SHoward Hinnant    // recurse on [__first, __m-1], except reduce __m-1 until *(__m-1) is true, *__first know to be false
34113e519524SHoward Hinnant    // F????????????????T
34123e519524SHoward Hinnant    // f       m        l
34133e519524SHoward Hinnant    _BidirectionalIterator __m1 = __m;
34143e519524SHoward Hinnant    _BidirectionalIterator __first_false = __first;
34153e519524SHoward Hinnant    _Distance __len_half = __len2;
34163e519524SHoward Hinnant    while (!__pred(*--__m1))
34173e519524SHoward Hinnant    {
34183e519524SHoward Hinnant        if (__m1 == __first)
34193e519524SHoward Hinnant            goto __first_half_done;
34203e519524SHoward Hinnant        --__len_half;
34213e519524SHoward Hinnant    }
34223e519524SHoward Hinnant    // F???TFFF?????????T
34233e519524SHoward Hinnant    // f   m1  m        l
34243e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Predicate>::type _PredRef;
34253e519524SHoward Hinnant    __first_false = __stable_partition<_PredRef>(__first, __m1, __pred, __len_half, __p, __bit);
34263e519524SHoward Hinnant__first_half_done:
34273e519524SHoward Hinnant    // TTTFFFFF?????????T
34283e519524SHoward Hinnant    // f  ff   m        l
34293e519524SHoward Hinnant    // recurse on [__m, __last], except increase __m until *(__m) is false, *__last know to be true
34303e519524SHoward Hinnant    __m1 = __m;
34313e519524SHoward Hinnant    _BidirectionalIterator __second_false = __last;
34323e519524SHoward Hinnant    ++__second_false;
34333e519524SHoward Hinnant    __len_half = __len - __len2;
34343e519524SHoward Hinnant    while (__pred(*__m1))
34353e519524SHoward Hinnant    {
34363e519524SHoward Hinnant        if (++__m1 == __last)
34373e519524SHoward Hinnant            goto __second_half_done;
34383e519524SHoward Hinnant        --__len_half;
34393e519524SHoward Hinnant    }
34403e519524SHoward Hinnant    // TTTFFFFFTTTF?????T
34413e519524SHoward Hinnant    // f  ff   m  m1    l
34423e519524SHoward Hinnant    __second_false = __stable_partition<_PredRef>(__m1, __last, __pred, __len_half, __p, __bit);
34433e519524SHoward Hinnant__second_half_done:
34443e519524SHoward Hinnant    // TTTFFFFFTTTTTFFFFF
34453e519524SHoward Hinnant    // f  ff   m    sf  l
3446ce48a113SHoward Hinnant    return _VSTD::rotate(__first_false, __m, __second_false);
34473e519524SHoward Hinnant    // TTTTTTTTFFFFFFFFFF
34483e519524SHoward Hinnant    //         |
34493e519524SHoward Hinnant}
34503e519524SHoward Hinnant
34513e519524SHoward Hinnanttemplate <class _Predicate, class _BidirectionalIterator>
34523e519524SHoward Hinnant_BidirectionalIterator
34533e519524SHoward Hinnant__stable_partition(_BidirectionalIterator __first, _BidirectionalIterator __last, _Predicate __pred,
34543e519524SHoward Hinnant                   bidirectional_iterator_tag)
34553e519524SHoward Hinnant{
34563e519524SHoward Hinnant    typedef typename iterator_traits<_BidirectionalIterator>::difference_type difference_type;
34573e519524SHoward Hinnant    typedef typename iterator_traits<_BidirectionalIterator>::value_type value_type;
34583e519524SHoward Hinnant    const difference_type __alloc_limit = 4;  // might want to make this a function of trivial assignment
34593e519524SHoward Hinnant    // Either prove all true and return __first or point to first false
34603e519524SHoward Hinnant    while (true)
34613e519524SHoward Hinnant    {
34623e519524SHoward Hinnant        if (__first == __last)
34633e519524SHoward Hinnant            return __first;
34643e519524SHoward Hinnant        if (!__pred(*__first))
34653e519524SHoward Hinnant            break;
34663e519524SHoward Hinnant        ++__first;
34673e519524SHoward Hinnant    }
34683e519524SHoward Hinnant    // __first points to first false, everything prior to __first is already set.
34693e519524SHoward Hinnant    // Either prove [__first, __last) is all false and return __first, or point __last to last true
34703e519524SHoward Hinnant    do
34713e519524SHoward Hinnant    {
34723e519524SHoward Hinnant        if (__first == --__last)
34733e519524SHoward Hinnant            return __first;
34743e519524SHoward Hinnant    } while (!__pred(*__last));
34753e519524SHoward Hinnant    // We now have a reduced range [__first, __last]
34763e519524SHoward Hinnant    // *__first is known to be false
34773e519524SHoward Hinnant    // *__last is known to be true
34783e519524SHoward Hinnant    // __len >= 2
3479ce48a113SHoward Hinnant    difference_type __len = _VSTD::distance(__first, __last) + 1;
34803e519524SHoward Hinnant    pair<value_type*, ptrdiff_t> __p(0, 0);
34813e519524SHoward Hinnant    unique_ptr<value_type, __return_temporary_buffer> __h;
34823e519524SHoward Hinnant    if (__len >= __alloc_limit)
34833e519524SHoward Hinnant    {
3484ce48a113SHoward Hinnant        __p = _VSTD::get_temporary_buffer<value_type>(__len);
34853e519524SHoward Hinnant        __h.reset(__p.first);
34863e519524SHoward Hinnant    }
34873e519524SHoward Hinnant    return __stable_partition<typename add_lvalue_reference<_Predicate>::type>
34883e519524SHoward Hinnant                             (__first, __last, __pred, __len, __p, bidirectional_iterator_tag());
34893e519524SHoward Hinnant}
34903e519524SHoward Hinnant
34913e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Predicate>
34923e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
34933e519524SHoward Hinnant_ForwardIterator
34943e519524SHoward Hinnantstable_partition(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred)
34953e519524SHoward Hinnant{
34963e519524SHoward Hinnant    return __stable_partition<typename add_lvalue_reference<_Predicate>::type>
34973e519524SHoward Hinnant                             (__first, __last, __pred, typename iterator_traits<_ForwardIterator>::iterator_category());
34983e519524SHoward Hinnant}
34993e519524SHoward Hinnant
35003e519524SHoward Hinnant// is_sorted_until
35013e519524SHoward Hinnant
35023e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Compare>
350349c7643cSMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
35043e519524SHoward Hinnantis_sorted_until(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp)
35053e519524SHoward Hinnant{
35063e519524SHoward Hinnant    if (__first != __last)
35073e519524SHoward Hinnant    {
35083e519524SHoward Hinnant        _ForwardIterator __i = __first;
35093e519524SHoward Hinnant        while (++__i != __last)
35103e519524SHoward Hinnant        {
35113e519524SHoward Hinnant            if (__comp(*__i, *__first))
35123e519524SHoward Hinnant                return __i;
35133e519524SHoward Hinnant            __first = __i;
35143e519524SHoward Hinnant        }
35153e519524SHoward Hinnant    }
35163e519524SHoward Hinnant    return __last;
35173e519524SHoward Hinnant}
35183e519524SHoward Hinnant
35193e519524SHoward Hinnanttemplate<class _ForwardIterator>
352049c7643cSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
35213e519524SHoward Hinnant_ForwardIterator
35223e519524SHoward Hinnantis_sorted_until(_ForwardIterator __first, _ForwardIterator __last)
35233e519524SHoward Hinnant{
3524ce48a113SHoward Hinnant    return _VSTD::is_sorted_until(__first, __last, __less<typename iterator_traits<_ForwardIterator>::value_type>());
35253e519524SHoward Hinnant}
35263e519524SHoward Hinnant
35273e519524SHoward Hinnant// is_sorted
35283e519524SHoward Hinnant
35293e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Compare>
353049c7643cSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
35313e519524SHoward Hinnantbool
35323e519524SHoward Hinnantis_sorted(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp)
35333e519524SHoward Hinnant{
3534ce48a113SHoward Hinnant    return _VSTD::is_sorted_until(__first, __last, __comp) == __last;
35353e519524SHoward Hinnant}
35363e519524SHoward Hinnant
35373e519524SHoward Hinnanttemplate<class _ForwardIterator>
353849c7643cSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
35393e519524SHoward Hinnantbool
35403e519524SHoward Hinnantis_sorted(_ForwardIterator __first, _ForwardIterator __last)
35413e519524SHoward Hinnant{
3542ce48a113SHoward Hinnant    return _VSTD::is_sorted(__first, __last, __less<typename iterator_traits<_ForwardIterator>::value_type>());
35433e519524SHoward Hinnant}
35443e519524SHoward Hinnant
35453e519524SHoward Hinnant// sort
35463e519524SHoward Hinnant
35473e519524SHoward Hinnant// stable, 2-3 compares, 0-2 swaps
35483e519524SHoward Hinnant
35493e519524SHoward Hinnanttemplate <class _Compare, class _ForwardIterator>
35503e519524SHoward Hinnantunsigned
35513e519524SHoward Hinnant__sort3(_ForwardIterator __x, _ForwardIterator __y, _ForwardIterator __z, _Compare __c)
35523e519524SHoward Hinnant{
35533e519524SHoward Hinnant    unsigned __r = 0;
35543e519524SHoward Hinnant    if (!__c(*__y, *__x))          // if x <= y
35553e519524SHoward Hinnant    {
35563e519524SHoward Hinnant        if (!__c(*__z, *__y))      // if y <= z
35573e519524SHoward Hinnant            return __r;            // x <= y && y <= z
35583e519524SHoward Hinnant                                   // x <= y && y > z
35593e519524SHoward Hinnant        swap(*__y, *__z);          // x <= z && y < z
35603e519524SHoward Hinnant        __r = 1;
35613e519524SHoward Hinnant        if (__c(*__y, *__x))       // if x > y
35623e519524SHoward Hinnant        {
35633e519524SHoward Hinnant            swap(*__x, *__y);      // x < y && y <= z
35643e519524SHoward Hinnant            __r = 2;
35653e519524SHoward Hinnant        }
35663e519524SHoward Hinnant        return __r;                // x <= y && y < z
35673e519524SHoward Hinnant    }
35683e519524SHoward Hinnant    if (__c(*__z, *__y))           // x > y, if y > z
35693e519524SHoward Hinnant    {
35703e519524SHoward Hinnant        swap(*__x, *__z);          // x < y && y < z
35713e519524SHoward Hinnant        __r = 1;
35723e519524SHoward Hinnant        return __r;
35733e519524SHoward Hinnant    }
35743e519524SHoward Hinnant    swap(*__x, *__y);              // x > y && y <= z
35753e519524SHoward Hinnant    __r = 1;                       // x < y && x <= z
35763e519524SHoward Hinnant    if (__c(*__z, *__y))           // if y > z
35773e519524SHoward Hinnant    {
35783e519524SHoward Hinnant        swap(*__y, *__z);          // x <= y && y < z
35793e519524SHoward Hinnant        __r = 2;
35803e519524SHoward Hinnant    }
35813e519524SHoward Hinnant    return __r;
35823e519524SHoward Hinnant}                                  // x <= y && y <= z
35833e519524SHoward Hinnant
35843e519524SHoward Hinnant// stable, 3-6 compares, 0-5 swaps
35853e519524SHoward Hinnant
35863e519524SHoward Hinnanttemplate <class _Compare, class _ForwardIterator>
35873e519524SHoward Hinnantunsigned
35883e519524SHoward Hinnant__sort4(_ForwardIterator __x1, _ForwardIterator __x2, _ForwardIterator __x3,
35893e519524SHoward Hinnant            _ForwardIterator __x4, _Compare __c)
35903e519524SHoward Hinnant{
35913e519524SHoward Hinnant    unsigned __r = __sort3<_Compare>(__x1, __x2, __x3, __c);
35923e519524SHoward Hinnant    if (__c(*__x4, *__x3))
35933e519524SHoward Hinnant    {
35943e519524SHoward Hinnant        swap(*__x3, *__x4);
35953e519524SHoward Hinnant        ++__r;
35963e519524SHoward Hinnant        if (__c(*__x3, *__x2))
35973e519524SHoward Hinnant        {
35983e519524SHoward Hinnant            swap(*__x2, *__x3);
35993e519524SHoward Hinnant            ++__r;
36003e519524SHoward Hinnant            if (__c(*__x2, *__x1))
36013e519524SHoward Hinnant            {
36023e519524SHoward Hinnant                swap(*__x1, *__x2);
36033e519524SHoward Hinnant                ++__r;
36043e519524SHoward Hinnant            }
36053e519524SHoward Hinnant        }
36063e519524SHoward Hinnant    }
36073e519524SHoward Hinnant    return __r;
36083e519524SHoward Hinnant}
36093e519524SHoward Hinnant
36103e519524SHoward Hinnant// stable, 4-10 compares, 0-9 swaps
36113e519524SHoward Hinnant
36123e519524SHoward Hinnanttemplate <class _Compare, class _ForwardIterator>
36133e519524SHoward Hinnantunsigned
36143e519524SHoward Hinnant__sort5(_ForwardIterator __x1, _ForwardIterator __x2, _ForwardIterator __x3,
36153e519524SHoward Hinnant            _ForwardIterator __x4, _ForwardIterator __x5, _Compare __c)
36163e519524SHoward Hinnant{
36173e519524SHoward Hinnant    unsigned __r = __sort4<_Compare>(__x1, __x2, __x3, __x4, __c);
36183e519524SHoward Hinnant    if (__c(*__x5, *__x4))
36193e519524SHoward Hinnant    {
36203e519524SHoward Hinnant        swap(*__x4, *__x5);
36213e519524SHoward Hinnant        ++__r;
36223e519524SHoward Hinnant        if (__c(*__x4, *__x3))
36233e519524SHoward Hinnant        {
36243e519524SHoward Hinnant            swap(*__x3, *__x4);
36253e519524SHoward Hinnant            ++__r;
36263e519524SHoward Hinnant            if (__c(*__x3, *__x2))
36273e519524SHoward Hinnant            {
36283e519524SHoward Hinnant                swap(*__x2, *__x3);
36293e519524SHoward Hinnant                ++__r;
36303e519524SHoward Hinnant                if (__c(*__x2, *__x1))
36313e519524SHoward Hinnant                {
36323e519524SHoward Hinnant                    swap(*__x1, *__x2);
36333e519524SHoward Hinnant                    ++__r;
36343e519524SHoward Hinnant                }
36353e519524SHoward Hinnant            }
36363e519524SHoward Hinnant        }
36373e519524SHoward Hinnant    }
36383e519524SHoward Hinnant    return __r;
36393e519524SHoward Hinnant}
36403e519524SHoward Hinnant
36413e519524SHoward Hinnant// Assumes size > 0
36423e519524SHoward Hinnanttemplate <class _Compare, class _BirdirectionalIterator>
36433e519524SHoward Hinnantvoid
36443e519524SHoward Hinnant__selection_sort(_BirdirectionalIterator __first, _BirdirectionalIterator __last, _Compare __comp)
36453e519524SHoward Hinnant{
36463e519524SHoward Hinnant    _BirdirectionalIterator __lm1 = __last;
36473e519524SHoward Hinnant    for (--__lm1; __first != __lm1; ++__first)
36483e519524SHoward Hinnant    {
3649ce48a113SHoward Hinnant        _BirdirectionalIterator __i = _VSTD::min_element<_BirdirectionalIterator,
36503e519524SHoward Hinnant                                                        typename add_lvalue_reference<_Compare>::type>
36513e519524SHoward Hinnant                                                       (__first, __last, __comp);
36523e519524SHoward Hinnant        if (__i != __first)
36533e519524SHoward Hinnant            swap(*__first, *__i);
36543e519524SHoward Hinnant    }
36553e519524SHoward Hinnant}
36563e519524SHoward Hinnant
36573e519524SHoward Hinnanttemplate <class _Compare, class _BirdirectionalIterator>
36583e519524SHoward Hinnantvoid
36593e519524SHoward Hinnant__insertion_sort(_BirdirectionalIterator __first, _BirdirectionalIterator __last, _Compare __comp)
36603e519524SHoward Hinnant{
36613e519524SHoward Hinnant    typedef typename iterator_traits<_BirdirectionalIterator>::value_type value_type;
36623e519524SHoward Hinnant    if (__first != __last)
36633e519524SHoward Hinnant    {
36643e519524SHoward Hinnant        _BirdirectionalIterator __i = __first;
36653e519524SHoward Hinnant        for (++__i; __i != __last; ++__i)
36663e519524SHoward Hinnant        {
36673e519524SHoward Hinnant            _BirdirectionalIterator __j = __i;
3668ce48a113SHoward Hinnant            value_type __t(_VSTD::move(*__j));
36693e519524SHoward Hinnant            for (_BirdirectionalIterator __k = __i; __k != __first && __comp(__t,  *--__k); --__j)
3670ce48a113SHoward Hinnant                *__j = _VSTD::move(*__k);
3671ce48a113SHoward Hinnant            *__j = _VSTD::move(__t);
36723e519524SHoward Hinnant        }
36733e519524SHoward Hinnant    }
36743e519524SHoward Hinnant}
36753e519524SHoward Hinnant
36763e519524SHoward Hinnanttemplate <class _Compare, class _RandomAccessIterator>
36773e519524SHoward Hinnantvoid
36783e519524SHoward Hinnant__insertion_sort_3(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
36793e519524SHoward Hinnant{
36803e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
36813e519524SHoward Hinnant    _RandomAccessIterator __j = __first+2;
36823e519524SHoward Hinnant    __sort3<_Compare>(__first, __first+1, __j, __comp);
36833e519524SHoward Hinnant    for (_RandomAccessIterator __i = __j+1; __i != __last; ++__i)
36843e519524SHoward Hinnant    {
36853e519524SHoward Hinnant        if (__comp(*__i, *__j))
36863e519524SHoward Hinnant        {
3687ce48a113SHoward Hinnant            value_type __t(_VSTD::move(*__i));
36883e519524SHoward Hinnant            _RandomAccessIterator __k = __j;
36893e519524SHoward Hinnant            __j = __i;
36903e519524SHoward Hinnant            do
36913e519524SHoward Hinnant            {
3692ce48a113SHoward Hinnant                *__j = _VSTD::move(*__k);
36933e519524SHoward Hinnant                __j = __k;
36943e519524SHoward Hinnant            } while (__j != __first && __comp(__t, *--__k));
3695ce48a113SHoward Hinnant            *__j = _VSTD::move(__t);
36963e519524SHoward Hinnant        }
36973e519524SHoward Hinnant        __j = __i;
36983e519524SHoward Hinnant    }
36993e519524SHoward Hinnant}
37003e519524SHoward Hinnant
37013e519524SHoward Hinnanttemplate <class _Compare, class _RandomAccessIterator>
37023e519524SHoward Hinnantbool
37033e519524SHoward Hinnant__insertion_sort_incomplete(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
37043e519524SHoward Hinnant{
37053e519524SHoward Hinnant    switch (__last - __first)
37063e519524SHoward Hinnant    {
37073e519524SHoward Hinnant    case 0:
37083e519524SHoward Hinnant    case 1:
37093e519524SHoward Hinnant        return true;
37103e519524SHoward Hinnant    case 2:
37113e519524SHoward Hinnant        if (__comp(*--__last, *__first))
37123e519524SHoward Hinnant            swap(*__first, *__last);
37133e519524SHoward Hinnant        return true;
37143e519524SHoward Hinnant    case 3:
3715ce48a113SHoward Hinnant        _VSTD::__sort3<_Compare>(__first, __first+1, --__last, __comp);
37163e519524SHoward Hinnant        return true;
37173e519524SHoward Hinnant    case 4:
3718ce48a113SHoward Hinnant        _VSTD::__sort4<_Compare>(__first, __first+1, __first+2, --__last, __comp);
37193e519524SHoward Hinnant        return true;
37203e519524SHoward Hinnant    case 5:
3721ce48a113SHoward Hinnant        _VSTD::__sort5<_Compare>(__first, __first+1, __first+2, __first+3, --__last, __comp);
37223e519524SHoward Hinnant        return true;
37233e519524SHoward Hinnant    }
37243e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
37253e519524SHoward Hinnant    _RandomAccessIterator __j = __first+2;
37263e519524SHoward Hinnant    __sort3<_Compare>(__first, __first+1, __j, __comp);
37273e519524SHoward Hinnant    const unsigned __limit = 8;
37283e519524SHoward Hinnant    unsigned __count = 0;
37293e519524SHoward Hinnant    for (_RandomAccessIterator __i = __j+1; __i != __last; ++__i)
37303e519524SHoward Hinnant    {
37313e519524SHoward Hinnant        if (__comp(*__i, *__j))
37323e519524SHoward Hinnant        {
3733ce48a113SHoward Hinnant            value_type __t(_VSTD::move(*__i));
37343e519524SHoward Hinnant            _RandomAccessIterator __k = __j;
37353e519524SHoward Hinnant            __j = __i;
37363e519524SHoward Hinnant            do
37373e519524SHoward Hinnant            {
3738ce48a113SHoward Hinnant                *__j = _VSTD::move(*__k);
37393e519524SHoward Hinnant                __j = __k;
37403e519524SHoward Hinnant            } while (__j != __first && __comp(__t, *--__k));
3741ce48a113SHoward Hinnant            *__j = _VSTD::move(__t);
37423e519524SHoward Hinnant            if (++__count == __limit)
37433e519524SHoward Hinnant                return ++__i == __last;
37443e519524SHoward Hinnant        }
37453e519524SHoward Hinnant        __j = __i;
37463e519524SHoward Hinnant    }
37473e519524SHoward Hinnant    return true;
37483e519524SHoward Hinnant}
37493e519524SHoward Hinnant
37503e519524SHoward Hinnanttemplate <class _Compare, class _BirdirectionalIterator>
37513e519524SHoward Hinnantvoid
37523e519524SHoward Hinnant__insertion_sort_move(_BirdirectionalIterator __first1, _BirdirectionalIterator __last1,
37533e519524SHoward Hinnant                      typename iterator_traits<_BirdirectionalIterator>::value_type* __first2, _Compare __comp)
37543e519524SHoward Hinnant{
37553e519524SHoward Hinnant    typedef typename iterator_traits<_BirdirectionalIterator>::value_type value_type;
37563e519524SHoward Hinnant    if (__first1 != __last1)
37573e519524SHoward Hinnant    {
37583e519524SHoward Hinnant        __destruct_n __d(0);
37593e519524SHoward Hinnant        unique_ptr<value_type, __destruct_n&> __h(__first2, __d);
37603e519524SHoward Hinnant        value_type* __last2 = __first2;
3761ce48a113SHoward Hinnant        ::new(__last2) value_type(_VSTD::move(*__first1));
37623e519524SHoward Hinnant        __d.__incr((value_type*)0);
37633e519524SHoward Hinnant        for (++__last2; ++__first1 != __last1; ++__last2)
37643e519524SHoward Hinnant        {
37653e519524SHoward Hinnant            value_type* __j2 = __last2;
37663e519524SHoward Hinnant            value_type* __i2 = __j2;
37673e519524SHoward Hinnant            if (__comp(*__first1, *--__i2))
37683e519524SHoward Hinnant            {
3769ce48a113SHoward Hinnant                ::new(__j2) value_type(_VSTD::move(*__i2));
37703e519524SHoward Hinnant                __d.__incr((value_type*)0);
37713e519524SHoward Hinnant                for (--__j2; __i2 != __first2 && __comp(*__first1,  *--__i2); --__j2)
3772ce48a113SHoward Hinnant                    *__j2 = _VSTD::move(*__i2);
3773ce48a113SHoward Hinnant                *__j2 = _VSTD::move(*__first1);
37743e519524SHoward Hinnant            }
37753e519524SHoward Hinnant            else
37763e519524SHoward Hinnant            {
3777ce48a113SHoward Hinnant                ::new(__j2) value_type(_VSTD::move(*__first1));
37783e519524SHoward Hinnant                __d.__incr((value_type*)0);
37793e519524SHoward Hinnant            }
37803e519524SHoward Hinnant        }
37813e519524SHoward Hinnant        __h.release();
37823e519524SHoward Hinnant    }
37833e519524SHoward Hinnant}
37843e519524SHoward Hinnant
37853e519524SHoward Hinnanttemplate <class _Compare, class _RandomAccessIterator>
37863e519524SHoward Hinnantvoid
37873e519524SHoward Hinnant__sort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
37883e519524SHoward Hinnant{
37893e519524SHoward Hinnant    // _Compare is known to be a reference type
37903e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
37913e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
3792ca740483SHoward Hinnant    const difference_type __limit = is_trivially_copy_constructible<value_type>::value &&
3793ca740483SHoward Hinnant                                    is_trivially_copy_assignable<value_type>::value ? 30 : 6;
37943e519524SHoward Hinnant    while (true)
37953e519524SHoward Hinnant    {
37963e519524SHoward Hinnant    __restart:
37973e519524SHoward Hinnant        difference_type __len = __last - __first;
37983e519524SHoward Hinnant        switch (__len)
37993e519524SHoward Hinnant        {
38003e519524SHoward Hinnant        case 0:
38013e519524SHoward Hinnant        case 1:
38023e519524SHoward Hinnant            return;
38033e519524SHoward Hinnant        case 2:
38043e519524SHoward Hinnant            if (__comp(*--__last, *__first))
38053e519524SHoward Hinnant                swap(*__first, *__last);
38063e519524SHoward Hinnant            return;
38073e519524SHoward Hinnant        case 3:
3808ce48a113SHoward Hinnant            _VSTD::__sort3<_Compare>(__first, __first+1, --__last, __comp);
38093e519524SHoward Hinnant            return;
38103e519524SHoward Hinnant        case 4:
3811ce48a113SHoward Hinnant            _VSTD::__sort4<_Compare>(__first, __first+1, __first+2, --__last, __comp);
38123e519524SHoward Hinnant            return;
38133e519524SHoward Hinnant        case 5:
3814ce48a113SHoward Hinnant            _VSTD::__sort5<_Compare>(__first, __first+1, __first+2, __first+3, --__last, __comp);
38153e519524SHoward Hinnant            return;
38163e519524SHoward Hinnant        }
38173e519524SHoward Hinnant        if (__len <= __limit)
38183e519524SHoward Hinnant        {
3819ce48a113SHoward Hinnant            _VSTD::__insertion_sort_3<_Compare>(__first, __last, __comp);
38203e519524SHoward Hinnant            return;
38213e519524SHoward Hinnant        }
38223e519524SHoward Hinnant        // __len > 5
38233e519524SHoward Hinnant        _RandomAccessIterator __m = __first;
38243e519524SHoward Hinnant        _RandomAccessIterator __lm1 = __last;
38253e519524SHoward Hinnant        --__lm1;
38263e519524SHoward Hinnant        unsigned __n_swaps;
38273e519524SHoward Hinnant        {
38283e519524SHoward Hinnant        difference_type __delta;
38293e519524SHoward Hinnant        if (__len >= 1000)
38303e519524SHoward Hinnant        {
38313e519524SHoward Hinnant            __delta = __len/2;
38323e519524SHoward Hinnant            __m += __delta;
38333e519524SHoward Hinnant            __delta /= 2;
3834ce48a113SHoward Hinnant            __n_swaps = _VSTD::__sort5<_Compare>(__first, __first + __delta, __m, __m+__delta, __lm1, __comp);
38353e519524SHoward Hinnant        }
38363e519524SHoward Hinnant        else
38373e519524SHoward Hinnant        {
38383e519524SHoward Hinnant            __delta = __len/2;
38393e519524SHoward Hinnant            __m += __delta;
3840ce48a113SHoward Hinnant            __n_swaps = _VSTD::__sort3<_Compare>(__first, __m, __lm1, __comp);
38413e519524SHoward Hinnant        }
38423e519524SHoward Hinnant        }
38433e519524SHoward Hinnant        // *__m is median
38443e519524SHoward Hinnant        // partition [__first, __m) < *__m and *__m <= [__m, __last)
38453e519524SHoward Hinnant        // (this inhibits tossing elements equivalent to __m around unnecessarily)
38463e519524SHoward Hinnant        _RandomAccessIterator __i = __first;
38473e519524SHoward Hinnant        _RandomAccessIterator __j = __lm1;
38483e519524SHoward Hinnant        // j points beyond range to be tested, *__m is known to be <= *__lm1
38493e519524SHoward Hinnant        // The search going up is known to be guarded but the search coming down isn't.
38503e519524SHoward Hinnant        // Prime the downward search with a guard.
38513e519524SHoward Hinnant        if (!__comp(*__i, *__m))  // if *__first == *__m
38523e519524SHoward Hinnant        {
38533e519524SHoward Hinnant            // *__first == *__m, *__first doesn't go in first part
38543e519524SHoward Hinnant            // manually guard downward moving __j against __i
38553e519524SHoward Hinnant            while (true)
38563e519524SHoward Hinnant            {
38573e519524SHoward Hinnant                if (__i == --__j)
38583e519524SHoward Hinnant                {
38593e519524SHoward Hinnant                    // *__first == *__m, *__m <= all other elements
38603e519524SHoward Hinnant                    // Parition instead into [__first, __i) == *__first and *__first < [__i, __last)
38613e519524SHoward Hinnant                    ++__i;  // __first + 1
38623e519524SHoward Hinnant                    __j = __last;
38633e519524SHoward Hinnant                    if (!__comp(*__first, *--__j))  // we need a guard if *__first == *(__last-1)
38643e519524SHoward Hinnant                    {
38653e519524SHoward Hinnant                        while (true)
38663e519524SHoward Hinnant                        {
38673e519524SHoward Hinnant                            if (__i == __j)
38683e519524SHoward Hinnant                                return;  // [__first, __last) all equivalent elements
38693e519524SHoward Hinnant                            if (__comp(*__first, *__i))
38703e519524SHoward Hinnant                            {
38713e519524SHoward Hinnant                                swap(*__i, *__j);
38723e519524SHoward Hinnant                                ++__n_swaps;
38733e519524SHoward Hinnant                                ++__i;
38743e519524SHoward Hinnant                                break;
38753e519524SHoward Hinnant                            }
38763e519524SHoward Hinnant                            ++__i;
38773e519524SHoward Hinnant                        }
38783e519524SHoward Hinnant                    }
38793e519524SHoward Hinnant                    // [__first, __i) == *__first and *__first < [__j, __last) and __j == __last - 1
38803e519524SHoward Hinnant                    if (__i == __j)
38813e519524SHoward Hinnant                        return;
38823e519524SHoward Hinnant                    while (true)
38833e519524SHoward Hinnant                    {
38843e519524SHoward Hinnant                        while (!__comp(*__first, *__i))
38853e519524SHoward Hinnant                            ++__i;
38863e519524SHoward Hinnant                        while (__comp(*__first, *--__j))
38873e519524SHoward Hinnant                            ;
38883e519524SHoward Hinnant                        if (__i >= __j)
38893e519524SHoward Hinnant                            break;
38903e519524SHoward Hinnant                        swap(*__i, *__j);
38913e519524SHoward Hinnant                        ++__n_swaps;
38923e519524SHoward Hinnant                        ++__i;
38933e519524SHoward Hinnant                    }
38943e519524SHoward Hinnant                    // [__first, __i) == *__first and *__first < [__i, __last)
38953e519524SHoward Hinnant                    // The first part is sorted, sort the secod part
3896ce48a113SHoward Hinnant                    // _VSTD::__sort<_Compare>(__i, __last, __comp);
38973e519524SHoward Hinnant                    __first = __i;
38983e519524SHoward Hinnant                    goto __restart;
38993e519524SHoward Hinnant                }
39003e519524SHoward Hinnant                if (__comp(*__j, *__m))
39013e519524SHoward Hinnant                {
39023e519524SHoward Hinnant                    swap(*__i, *__j);
39033e519524SHoward Hinnant                    ++__n_swaps;
39043e519524SHoward Hinnant                    break;  // found guard for downward moving __j, now use unguarded partition
39053e519524SHoward Hinnant                }
39063e519524SHoward Hinnant            }
39073e519524SHoward Hinnant        }
39083e519524SHoward Hinnant        // It is known that *__i < *__m
39093e519524SHoward Hinnant        ++__i;
39103e519524SHoward Hinnant        // j points beyond range to be tested, *__m is known to be <= *__lm1
39113e519524SHoward Hinnant        // if not yet partitioned...
39123e519524SHoward Hinnant        if (__i < __j)
39133e519524SHoward Hinnant        {
39143e519524SHoward Hinnant            // known that *(__i - 1) < *__m
39153e519524SHoward Hinnant            // known that __i <= __m
39163e519524SHoward Hinnant            while (true)
39173e519524SHoward Hinnant            {
39183e519524SHoward Hinnant                // __m still guards upward moving __i
39193e519524SHoward Hinnant                while (__comp(*__i, *__m))
39203e519524SHoward Hinnant                    ++__i;
39213e519524SHoward Hinnant                // It is now known that a guard exists for downward moving __j
39223e519524SHoward Hinnant                while (!__comp(*--__j, *__m))
39233e519524SHoward Hinnant                    ;
39243e519524SHoward Hinnant                if (__i > __j)
39253e519524SHoward Hinnant                    break;
39263e519524SHoward Hinnant                swap(*__i, *__j);
39273e519524SHoward Hinnant                ++__n_swaps;
39283e519524SHoward Hinnant                // It is known that __m != __j
39293e519524SHoward Hinnant                // If __m just moved, follow it
39303e519524SHoward Hinnant                if (__m == __i)
39313e519524SHoward Hinnant                    __m = __j;
39323e519524SHoward Hinnant                ++__i;
39333e519524SHoward Hinnant            }
39343e519524SHoward Hinnant        }
39353e519524SHoward Hinnant        // [__first, __i) < *__m and *__m <= [__i, __last)
39363e519524SHoward Hinnant        if (__i != __m && __comp(*__m, *__i))
39373e519524SHoward Hinnant        {
39383e519524SHoward Hinnant            swap(*__i, *__m);
39393e519524SHoward Hinnant            ++__n_swaps;
39403e519524SHoward Hinnant        }
39413e519524SHoward Hinnant        // [__first, __i) < *__i and *__i <= [__i+1, __last)
39423e519524SHoward Hinnant        // If we were given a perfect partition, see if insertion sort is quick...
39433e519524SHoward Hinnant        if (__n_swaps == 0)
39443e519524SHoward Hinnant        {
3945ce48a113SHoward Hinnant            bool __fs = _VSTD::__insertion_sort_incomplete<_Compare>(__first, __i, __comp);
3946ce48a113SHoward Hinnant            if (_VSTD::__insertion_sort_incomplete<_Compare>(__i+1, __last, __comp))
39473e519524SHoward Hinnant            {
39483e519524SHoward Hinnant                if (__fs)
39493e519524SHoward Hinnant                    return;
39503e519524SHoward Hinnant                __last = __i;
39513e519524SHoward Hinnant                continue;
39523e519524SHoward Hinnant            }
39533e519524SHoward Hinnant            else
39543e519524SHoward Hinnant            {
39553e519524SHoward Hinnant                if (__fs)
39563e519524SHoward Hinnant                {
39573e519524SHoward Hinnant                    __first = ++__i;
39583e519524SHoward Hinnant                    continue;
39593e519524SHoward Hinnant                }
39603e519524SHoward Hinnant            }
39613e519524SHoward Hinnant        }
39623e519524SHoward Hinnant        // sort smaller range with recursive call and larger with tail recursion elimination
39633e519524SHoward Hinnant        if (__i - __first < __last - __i)
39643e519524SHoward Hinnant        {
3965ce48a113SHoward Hinnant            _VSTD::__sort<_Compare>(__first, __i, __comp);
3966ce48a113SHoward Hinnant            // _VSTD::__sort<_Compare>(__i+1, __last, __comp);
39673e519524SHoward Hinnant            __first = ++__i;
39683e519524SHoward Hinnant        }
39693e519524SHoward Hinnant        else
39703e519524SHoward Hinnant        {
3971ce48a113SHoward Hinnant            _VSTD::__sort<_Compare>(__i+1, __last, __comp);
3972ce48a113SHoward Hinnant            // _VSTD::__sort<_Compare>(__first, __i, __comp);
39733e519524SHoward Hinnant            __last = __i;
39743e519524SHoward Hinnant        }
39753e519524SHoward Hinnant    }
39763e519524SHoward Hinnant}
39773e519524SHoward Hinnant
39783e519524SHoward Hinnant// This forwarder keeps the top call and the recursive calls using the same instantiation, forcing a reference _Compare
39793e519524SHoward Hinnanttemplate <class _RandomAccessIterator, class _Compare>
39803e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
39813e519524SHoward Hinnantvoid
39823e519524SHoward Hinnantsort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
39833e519524SHoward Hinnant{
3984145afa17SHoward Hinnant#ifdef _LIBCPP_DEBUG
39853e519524SHoward Hinnant    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
39863e519524SHoward Hinnant    __debug_less<_Compare> __c(__comp);
39873e519524SHoward Hinnant    __sort<_Comp_ref>(__first, __last, __c);
3988145afa17SHoward Hinnant#else  // _LIBCPP_DEBUG
39893e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
39903e519524SHoward Hinnant    __sort<_Comp_ref>(__first, __last, __comp);
3991145afa17SHoward Hinnant#endif  // _LIBCPP_DEBUG
39923e519524SHoward Hinnant}
39933e519524SHoward Hinnant
39943e519524SHoward Hinnanttemplate <class _RandomAccessIterator>
39953e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
39963e519524SHoward Hinnantvoid
39973e519524SHoward Hinnantsort(_RandomAccessIterator __first, _RandomAccessIterator __last)
39983e519524SHoward Hinnant{
3999ce48a113SHoward Hinnant    _VSTD::sort(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
40003e519524SHoward Hinnant}
40013e519524SHoward Hinnant
40023e519524SHoward Hinnanttemplate <class _Tp>
40033e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
40043e519524SHoward Hinnantvoid
40053e519524SHoward Hinnantsort(_Tp** __first, _Tp** __last)
40063e519524SHoward Hinnant{
4007ce48a113SHoward Hinnant    _VSTD::sort((size_t*)__first, (size_t*)__last, __less<size_t>());
40083e519524SHoward Hinnant}
40093e519524SHoward Hinnant
40103e519524SHoward Hinnanttemplate <class _Tp>
40113e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
40123e519524SHoward Hinnantvoid
40133e519524SHoward Hinnantsort(__wrap_iter<_Tp*> __first, __wrap_iter<_Tp*> __last)
40143e519524SHoward Hinnant{
4015ce48a113SHoward Hinnant    _VSTD::sort(__first.base(), __last.base());
40163e519524SHoward Hinnant}
40173e519524SHoward Hinnant
4018f554add5SHoward Hinnanttemplate <class _Tp, class _Compare>
4019f554add5SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
4020f554add5SHoward Hinnantvoid
4021f554add5SHoward Hinnantsort(__wrap_iter<_Tp*> __first, __wrap_iter<_Tp*> __last, _Compare __comp)
4022f554add5SHoward Hinnant{
4023f554add5SHoward Hinnant    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
4024f554add5SHoward Hinnant    _VSTD::sort<_Tp*, _Comp_ref>(__first.base(), __last.base(), __comp);
4025f554add5SHoward Hinnant}
4026f554add5SHoward Hinnant
4027f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<char>&, char*>(char*, char*, __less<char>&))
4028f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<wchar_t>&, wchar_t*>(wchar_t*, wchar_t*, __less<wchar_t>&))
4029f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<signed char>&, signed char*>(signed char*, signed char*, __less<signed char>&))
4030f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<unsigned char>&, unsigned char*>(unsigned char*, unsigned char*, __less<unsigned char>&))
4031f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<short>&, short*>(short*, short*, __less<short>&))
4032f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<unsigned short>&, unsigned short*>(unsigned short*, unsigned short*, __less<unsigned short>&))
4033f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<int>&, int*>(int*, int*, __less<int>&))
4034f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<unsigned>&, unsigned*>(unsigned*, unsigned*, __less<unsigned>&))
4035f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<long>&, long*>(long*, long*, __less<long>&))
4036f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<unsigned long>&, unsigned long*>(unsigned long*, unsigned long*, __less<unsigned long>&))
4037f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<long long>&, long long*>(long long*, long long*, __less<long long>&))
4038f0544c20SHoward 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>&))
4039f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<float>&, float*>(float*, float*, __less<float>&))
4040f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<double>&, double*>(double*, double*, __less<double>&))
4041f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<long double>&, long double*>(long double*, long double*, __less<long double>&))
40423e519524SHoward Hinnant
4043f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<char>&, char*>(char*, char*, __less<char>&))
4044f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<wchar_t>&, wchar_t*>(wchar_t*, wchar_t*, __less<wchar_t>&))
4045f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<signed char>&, signed char*>(signed char*, signed char*, __less<signed char>&))
4046f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<unsigned char>&, unsigned char*>(unsigned char*, unsigned char*, __less<unsigned char>&))
4047f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<short>&, short*>(short*, short*, __less<short>&))
4048f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<unsigned short>&, unsigned short*>(unsigned short*, unsigned short*, __less<unsigned short>&))
4049f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<int>&, int*>(int*, int*, __less<int>&))
4050f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<unsigned>&, unsigned*>(unsigned*, unsigned*, __less<unsigned>&))
4051f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<long>&, long*>(long*, long*, __less<long>&))
4052f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<unsigned long>&, unsigned long*>(unsigned long*, unsigned long*, __less<unsigned long>&))
4053f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<long long>&, long long*>(long long*, long long*, __less<long long>&))
4054f0544c20SHoward 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>&))
4055f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<float>&, float*>(float*, float*, __less<float>&))
4056f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<double>&, double*>(double*, double*, __less<double>&))
4057f0544c20SHoward Hinnant_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<long double>&, long double*>(long double*, long double*, __less<long double>&))
40583e519524SHoward Hinnant
4059f0544c20SHoward 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>&))
40603e519524SHoward Hinnant
40613e519524SHoward Hinnant// lower_bound
40623e519524SHoward Hinnant
40633e519524SHoward Hinnanttemplate <class _Compare, class _ForwardIterator, class _Tp>
4064d57c03ddSMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
4065e4383379SHoward Hinnant__lower_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
40663e519524SHoward Hinnant{
40673e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator>::difference_type difference_type;
4068ce48a113SHoward Hinnant    difference_type __len = _VSTD::distance(__first, __last);
40693e519524SHoward Hinnant    while (__len != 0)
40703e519524SHoward Hinnant    {
40713e519524SHoward Hinnant        difference_type __l2 = __len / 2;
40723e519524SHoward Hinnant        _ForwardIterator __m = __first;
4073ce48a113SHoward Hinnant        _VSTD::advance(__m, __l2);
4074e4383379SHoward Hinnant        if (__comp(*__m, __value_))
40753e519524SHoward Hinnant        {
40763e519524SHoward Hinnant            __first = ++__m;
40773e519524SHoward Hinnant            __len -= __l2 + 1;
40783e519524SHoward Hinnant        }
40793e519524SHoward Hinnant        else
40803e519524SHoward Hinnant            __len = __l2;
40813e519524SHoward Hinnant    }
40823e519524SHoward Hinnant    return __first;
40833e519524SHoward Hinnant}
40843e519524SHoward Hinnant
40853e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Tp, class _Compare>
4086d57c03ddSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
40873e519524SHoward Hinnant_ForwardIterator
4088e4383379SHoward Hinnantlower_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
40893e519524SHoward Hinnant{
4090145afa17SHoward Hinnant#ifdef _LIBCPP_DEBUG
40913e519524SHoward Hinnant    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
40923e519524SHoward Hinnant    __debug_less<_Compare> __c(__comp);
4093e4383379SHoward Hinnant    return __lower_bound<_Comp_ref>(__first, __last, __value_, __c);
4094145afa17SHoward Hinnant#else  // _LIBCPP_DEBUG
40953e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
4096e4383379SHoward Hinnant    return __lower_bound<_Comp_ref>(__first, __last, __value_, __comp);
4097145afa17SHoward Hinnant#endif  // _LIBCPP_DEBUG
40983e519524SHoward Hinnant}
40993e519524SHoward Hinnant
41003e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Tp>
4101d57c03ddSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
41023e519524SHoward Hinnant_ForwardIterator
4103e4383379SHoward Hinnantlower_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_)
41043e519524SHoward Hinnant{
4105e4383379SHoward Hinnant    return _VSTD::lower_bound(__first, __last, __value_,
41063e519524SHoward Hinnant                             __less<typename iterator_traits<_ForwardIterator>::value_type, _Tp>());
41073e519524SHoward Hinnant}
41083e519524SHoward Hinnant
41093e519524SHoward Hinnant// upper_bound
41103e519524SHoward Hinnant
41113e519524SHoward Hinnanttemplate <class _Compare, class _ForwardIterator, class _Tp>
4112d57c03ddSMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
4113e4383379SHoward Hinnant__upper_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
41143e519524SHoward Hinnant{
41153e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator>::difference_type difference_type;
4116ce48a113SHoward Hinnant    difference_type __len = _VSTD::distance(__first, __last);
41173e519524SHoward Hinnant    while (__len != 0)
41183e519524SHoward Hinnant    {
41193e519524SHoward Hinnant        difference_type __l2 = __len / 2;
41203e519524SHoward Hinnant        _ForwardIterator __m = __first;
4121ce48a113SHoward Hinnant        _VSTD::advance(__m, __l2);
4122e4383379SHoward Hinnant        if (__comp(__value_, *__m))
41233e519524SHoward Hinnant            __len = __l2;
41243e519524SHoward Hinnant        else
41253e519524SHoward Hinnant        {
41263e519524SHoward Hinnant            __first = ++__m;
41273e519524SHoward Hinnant            __len -= __l2 + 1;
41283e519524SHoward Hinnant        }
41293e519524SHoward Hinnant    }
41303e519524SHoward Hinnant    return __first;
41313e519524SHoward Hinnant}
41323e519524SHoward Hinnant
41333e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Tp, class _Compare>
4134d57c03ddSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
41353e519524SHoward Hinnant_ForwardIterator
4136e4383379SHoward Hinnantupper_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
41373e519524SHoward Hinnant{
4138145afa17SHoward Hinnant#ifdef _LIBCPP_DEBUG
41393e519524SHoward Hinnant    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
41403e519524SHoward Hinnant    __debug_less<_Compare> __c(__comp);
4141e4383379SHoward Hinnant    return __upper_bound<_Comp_ref>(__first, __last, __value_, __c);
4142145afa17SHoward Hinnant#else  // _LIBCPP_DEBUG
41433e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
4144e4383379SHoward Hinnant    return __upper_bound<_Comp_ref>(__first, __last, __value_, __comp);
4145145afa17SHoward Hinnant#endif  // _LIBCPP_DEBUG
41463e519524SHoward Hinnant}
41473e519524SHoward Hinnant
41483e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Tp>
4149d57c03ddSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
41503e519524SHoward Hinnant_ForwardIterator
4151e4383379SHoward Hinnantupper_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_)
41523e519524SHoward Hinnant{
4153e4383379SHoward Hinnant    return _VSTD::upper_bound(__first, __last, __value_,
41543e519524SHoward Hinnant                             __less<_Tp, typename iterator_traits<_ForwardIterator>::value_type>());
41553e519524SHoward Hinnant}
41563e519524SHoward Hinnant
41573e519524SHoward Hinnant// equal_range
41583e519524SHoward Hinnant
41593e519524SHoward Hinnanttemplate <class _Compare, class _ForwardIterator, class _Tp>
4160d57c03ddSMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 pair<_ForwardIterator, _ForwardIterator>
4161e4383379SHoward Hinnant__equal_range(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
41623e519524SHoward Hinnant{
41633e519524SHoward Hinnant    typedef typename iterator_traits<_ForwardIterator>::difference_type difference_type;
4164ce48a113SHoward Hinnant    difference_type __len = _VSTD::distance(__first, __last);
41653e519524SHoward Hinnant    while (__len != 0)
41663e519524SHoward Hinnant    {
41673e519524SHoward Hinnant        difference_type __l2 = __len / 2;
41683e519524SHoward Hinnant        _ForwardIterator __m = __first;
4169ce48a113SHoward Hinnant        _VSTD::advance(__m, __l2);
4170e4383379SHoward Hinnant        if (__comp(*__m, __value_))
41713e519524SHoward Hinnant        {
41723e519524SHoward Hinnant            __first = ++__m;
41733e519524SHoward Hinnant            __len -= __l2 + 1;
41743e519524SHoward Hinnant        }
4175e4383379SHoward Hinnant        else if (__comp(__value_, *__m))
41763e519524SHoward Hinnant        {
41773e519524SHoward Hinnant            __last = __m;
41783e519524SHoward Hinnant            __len = __l2;
41793e519524SHoward Hinnant        }
41803e519524SHoward Hinnant        else
41813e519524SHoward Hinnant        {
41823e519524SHoward Hinnant            _ForwardIterator __mp1 = __m;
41833e519524SHoward Hinnant            return pair<_ForwardIterator, _ForwardIterator>
41843e519524SHoward Hinnant                   (
4185e4383379SHoward Hinnant                      __lower_bound<_Compare>(__first, __m, __value_, __comp),
4186e4383379SHoward Hinnant                      __upper_bound<_Compare>(++__mp1, __last, __value_, __comp)
41873e519524SHoward Hinnant                   );
41883e519524SHoward Hinnant        }
41893e519524SHoward Hinnant    }
41903e519524SHoward Hinnant    return pair<_ForwardIterator, _ForwardIterator>(__first, __first);
41913e519524SHoward Hinnant}
41923e519524SHoward Hinnant
41933e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Tp, class _Compare>
4194d57c03ddSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
41953e519524SHoward Hinnantpair<_ForwardIterator, _ForwardIterator>
4196e4383379SHoward Hinnantequal_range(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
41973e519524SHoward Hinnant{
4198145afa17SHoward Hinnant#ifdef _LIBCPP_DEBUG
41993e519524SHoward Hinnant    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
42003e519524SHoward Hinnant    __debug_less<_Compare> __c(__comp);
4201e4383379SHoward Hinnant    return __equal_range<_Comp_ref>(__first, __last, __value_, __c);
4202145afa17SHoward Hinnant#else  // _LIBCPP_DEBUG
42033e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
4204e4383379SHoward Hinnant    return __equal_range<_Comp_ref>(__first, __last, __value_, __comp);
4205145afa17SHoward Hinnant#endif  // _LIBCPP_DEBUG
42063e519524SHoward Hinnant}
42073e519524SHoward Hinnant
42083e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Tp>
4209d57c03ddSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
42103e519524SHoward Hinnantpair<_ForwardIterator, _ForwardIterator>
4211e4383379SHoward Hinnantequal_range(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_)
42123e519524SHoward Hinnant{
4213e4383379SHoward Hinnant    return _VSTD::equal_range(__first, __last, __value_,
42143e519524SHoward Hinnant                             __less<typename iterator_traits<_ForwardIterator>::value_type, _Tp>());
42153e519524SHoward Hinnant}
42163e519524SHoward Hinnant
42173e519524SHoward Hinnant// binary_search
42183e519524SHoward Hinnant
42193e519524SHoward Hinnanttemplate <class _Compare, class _ForwardIterator, class _Tp>
4220d57c03ddSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
42213e519524SHoward Hinnantbool
4222e4383379SHoward Hinnant__binary_search(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
42233e519524SHoward Hinnant{
4224e4383379SHoward Hinnant    __first = __lower_bound<_Compare>(__first, __last, __value_, __comp);
4225e4383379SHoward Hinnant    return __first != __last && !__comp(__value_, *__first);
42263e519524SHoward Hinnant}
42273e519524SHoward Hinnant
42283e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Tp, class _Compare>
4229d57c03ddSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
42303e519524SHoward Hinnantbool
4231e4383379SHoward Hinnantbinary_search(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
42323e519524SHoward Hinnant{
4233145afa17SHoward Hinnant#ifdef _LIBCPP_DEBUG
42343e519524SHoward Hinnant    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
42353e519524SHoward Hinnant    __debug_less<_Compare> __c(__comp);
4236e4383379SHoward Hinnant    return __binary_search<_Comp_ref>(__first, __last, __value_, __c);
4237145afa17SHoward Hinnant#else  // _LIBCPP_DEBUG
42383e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
4239e4383379SHoward Hinnant    return __binary_search<_Comp_ref>(__first, __last, __value_, __comp);
4240145afa17SHoward Hinnant#endif  // _LIBCPP_DEBUG
42413e519524SHoward Hinnant}
42423e519524SHoward Hinnant
42433e519524SHoward Hinnanttemplate <class _ForwardIterator, class _Tp>
4244d57c03ddSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
42453e519524SHoward Hinnantbool
4246e4383379SHoward Hinnantbinary_search(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_)
42473e519524SHoward Hinnant{
4248e4383379SHoward Hinnant    return _VSTD::binary_search(__first, __last, __value_,
42493e519524SHoward Hinnant                             __less<typename iterator_traits<_ForwardIterator>::value_type, _Tp>());
42503e519524SHoward Hinnant}
42513e519524SHoward Hinnant
42523e519524SHoward Hinnant// merge
42533e519524SHoward Hinnant
42543e519524SHoward Hinnanttemplate <class _Compare, class _InputIterator1, class _InputIterator2, class _OutputIterator>
42553e519524SHoward Hinnant_OutputIterator
42563e519524SHoward Hinnant__merge(_InputIterator1 __first1, _InputIterator1 __last1,
42573e519524SHoward Hinnant        _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
42583e519524SHoward Hinnant{
42593e519524SHoward Hinnant    for (; __first1 != __last1; ++__result)
42603e519524SHoward Hinnant    {
42613e519524SHoward Hinnant        if (__first2 == __last2)
4262ce48a113SHoward Hinnant            return _VSTD::copy(__first1, __last1, __result);
42633e519524SHoward Hinnant        if (__comp(*__first2, *__first1))
42643e519524SHoward Hinnant        {
42653e519524SHoward Hinnant            *__result = *__first2;
42663e519524SHoward Hinnant            ++__first2;
42673e519524SHoward Hinnant        }
42683e519524SHoward Hinnant        else
42693e519524SHoward Hinnant        {
42703e519524SHoward Hinnant            *__result = *__first1;
42713e519524SHoward Hinnant            ++__first1;
42723e519524SHoward Hinnant        }
42733e519524SHoward Hinnant    }
4274ce48a113SHoward Hinnant    return _VSTD::copy(__first2, __last2, __result);
42753e519524SHoward Hinnant}
42763e519524SHoward Hinnant
42773e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
42783e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
42793e519524SHoward Hinnant_OutputIterator
42803e519524SHoward Hinnantmerge(_InputIterator1 __first1, _InputIterator1 __last1,
42813e519524SHoward Hinnant      _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
42823e519524SHoward Hinnant{
4283145afa17SHoward Hinnant#ifdef _LIBCPP_DEBUG
42843e519524SHoward Hinnant    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
42853e519524SHoward Hinnant    __debug_less<_Compare> __c(__comp);
4286ce48a113SHoward Hinnant    return _VSTD::__merge<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __c);
4287145afa17SHoward Hinnant#else  // _LIBCPP_DEBUG
42883e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
4289ce48a113SHoward Hinnant    return _VSTD::__merge<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __comp);
4290145afa17SHoward Hinnant#endif  // _LIBCPP_DEBUG
42913e519524SHoward Hinnant}
42923e519524SHoward Hinnant
42933e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _OutputIterator>
42943e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
42953e519524SHoward Hinnant_OutputIterator
42963e519524SHoward Hinnantmerge(_InputIterator1 __first1, _InputIterator1 __last1,
42973e519524SHoward Hinnant      _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result)
42983e519524SHoward Hinnant{
42993e519524SHoward Hinnant    typedef typename iterator_traits<_InputIterator1>::value_type __v1;
43003e519524SHoward Hinnant    typedef typename iterator_traits<_InputIterator2>::value_type __v2;
43013e519524SHoward Hinnant    return merge(__first1, __last1, __first2, __last2, __result, __less<__v1, __v2>());
43023e519524SHoward Hinnant}
43033e519524SHoward Hinnant
43043e519524SHoward Hinnant// inplace_merge
43053e519524SHoward Hinnant
4306adfdae18SMarshall Clowtemplate <class _Compare, class _InputIterator1, class _InputIterator2,
4307adfdae18SMarshall Clow          class _OutputIterator>
4308adfdae18SMarshall Clowvoid __half_inplace_merge(_InputIterator1 __first1, _InputIterator1 __last1,
4309adfdae18SMarshall Clow                          _InputIterator2 __first2, _InputIterator2 __last2,
4310adfdae18SMarshall Clow                          _OutputIterator __result, _Compare __comp)
4311adfdae18SMarshall Clow{
4312adfdae18SMarshall Clow    for (; __first1 != __last1; ++__result)
4313adfdae18SMarshall Clow    {
4314adfdae18SMarshall Clow        if (__first2 == __last2)
4315adfdae18SMarshall Clow        {
4316adfdae18SMarshall Clow            _VSTD::move(__first1, __last1, __result);
4317adfdae18SMarshall Clow            return;
4318adfdae18SMarshall Clow        }
4319adfdae18SMarshall Clow
4320adfdae18SMarshall Clow        if (__comp(*__first2, *__first1))
4321adfdae18SMarshall Clow        {
4322adfdae18SMarshall Clow            *__result = _VSTD::move(*__first2);
4323adfdae18SMarshall Clow            ++__first2;
4324adfdae18SMarshall Clow        }
4325adfdae18SMarshall Clow        else
4326adfdae18SMarshall Clow        {
4327adfdae18SMarshall Clow            *__result = _VSTD::move(*__first1);
4328adfdae18SMarshall Clow            ++__first1;
4329adfdae18SMarshall Clow        }
4330adfdae18SMarshall Clow    }
4331adfdae18SMarshall Clow    // __first2 through __last2 are already in the right spot.
4332adfdae18SMarshall Clow}
4333adfdae18SMarshall Clow
43343e519524SHoward Hinnanttemplate <class _Compare, class _BidirectionalIterator>
43353e519524SHoward Hinnantvoid
43363e519524SHoward Hinnant__buffered_inplace_merge(_BidirectionalIterator __first, _BidirectionalIterator __middle, _BidirectionalIterator __last,
43373e519524SHoward Hinnant                _Compare __comp, typename iterator_traits<_BidirectionalIterator>::difference_type __len1,
43383e519524SHoward Hinnant                                 typename iterator_traits<_BidirectionalIterator>::difference_type __len2,
43393e519524SHoward Hinnant                typename iterator_traits<_BidirectionalIterator>::value_type* __buff)
43403e519524SHoward Hinnant{
43413e519524SHoward Hinnant    typedef typename iterator_traits<_BidirectionalIterator>::value_type value_type;
43423e519524SHoward Hinnant    __destruct_n __d(0);
43433e519524SHoward Hinnant    unique_ptr<value_type, __destruct_n&> __h2(__buff, __d);
43443e519524SHoward Hinnant    if (__len1 <= __len2)
43453e519524SHoward Hinnant    {
43463e519524SHoward Hinnant        value_type* __p = __buff;
4347910285b2SEric Fiselier        for (_BidirectionalIterator __i = __first; __i != __middle; __d.__incr((value_type*)0), (void) ++__i, ++__p)
4348ce48a113SHoward Hinnant            ::new(__p) value_type(_VSTD::move(*__i));
4349adfdae18SMarshall Clow        __half_inplace_merge(__buff, __p, __middle, __last, __first, __comp);
43503e519524SHoward Hinnant    }
43513e519524SHoward Hinnant    else
43523e519524SHoward Hinnant    {
43533e519524SHoward Hinnant        value_type* __p = __buff;
4354910285b2SEric Fiselier        for (_BidirectionalIterator __i = __middle; __i != __last; __d.__incr((value_type*)0), (void) ++__i, ++__p)
4355ce48a113SHoward Hinnant            ::new(__p) value_type(_VSTD::move(*__i));
43563e519524SHoward Hinnant        typedef reverse_iterator<_BidirectionalIterator> _RBi;
43573e519524SHoward Hinnant        typedef reverse_iterator<value_type*> _Rv;
4358adfdae18SMarshall Clow        __half_inplace_merge(_Rv(__p), _Rv(__buff),
4359adfdae18SMarshall Clow                             _RBi(__middle), _RBi(__first),
4360a763b36fSMarshall Clow                             _RBi(__last), __invert<_Compare>(__comp));
43613e519524SHoward Hinnant    }
43623e519524SHoward Hinnant}
43633e519524SHoward Hinnant
43643e519524SHoward Hinnanttemplate <class _Compare, class _BidirectionalIterator>
43653e519524SHoward Hinnantvoid
43663e519524SHoward Hinnant__inplace_merge(_BidirectionalIterator __first, _BidirectionalIterator __middle, _BidirectionalIterator __last,
43673e519524SHoward Hinnant                _Compare __comp, typename iterator_traits<_BidirectionalIterator>::difference_type __len1,
43683e519524SHoward Hinnant                                 typename iterator_traits<_BidirectionalIterator>::difference_type __len2,
43693e519524SHoward Hinnant                typename iterator_traits<_BidirectionalIterator>::value_type* __buff, ptrdiff_t __buff_size)
43703e519524SHoward Hinnant{
43713e519524SHoward Hinnant    typedef typename iterator_traits<_BidirectionalIterator>::difference_type difference_type;
43723e519524SHoward Hinnant    while (true)
43733e519524SHoward Hinnant    {
43743e519524SHoward Hinnant        // if __middle == __last, we're done
43753e519524SHoward Hinnant        if (__len2 == 0)
43763e519524SHoward Hinnant            return;
4377526e0929SMarshall Clow        if (__len1 <= __buff_size || __len2 <= __buff_size)
4378526e0929SMarshall Clow            return __buffered_inplace_merge<_Compare>
4379526e0929SMarshall Clow                   (__first, __middle, __last, __comp, __len1, __len2, __buff);
43803e519524SHoward Hinnant        // shrink [__first, __middle) as much as possible (with no moves), returning if it shrinks to 0
4381910285b2SEric Fiselier        for (; true; ++__first, (void) --__len1)
43823e519524SHoward Hinnant        {
43833e519524SHoward Hinnant            if (__len1 == 0)
43843e519524SHoward Hinnant                return;
43853e519524SHoward Hinnant            if (__comp(*__middle, *__first))
43863e519524SHoward Hinnant                break;
43873e519524SHoward Hinnant        }
43883e519524SHoward Hinnant        // __first < __middle < __last
43893e519524SHoward Hinnant        // *__first > *__middle
43903e519524SHoward Hinnant        // partition [__first, __m1) [__m1, __middle) [__middle, __m2) [__m2, __last) such that
43913e519524SHoward Hinnant        //     all elements in:
43923e519524SHoward Hinnant        //         [__first, __m1)  <= [__middle, __m2)
43933e519524SHoward Hinnant        //         [__middle, __m2) <  [__m1, __middle)
43943e519524SHoward Hinnant        //         [__m1, __middle) <= [__m2, __last)
43953e519524SHoward Hinnant        //     and __m1 or __m2 is in the middle of its range
43963e519524SHoward Hinnant        _BidirectionalIterator __m1;  // "median" of [__first, __middle)
43973e519524SHoward Hinnant        _BidirectionalIterator __m2;  // "median" of [__middle, __last)
43983e519524SHoward Hinnant        difference_type __len11;      // distance(__first, __m1)
43993e519524SHoward Hinnant        difference_type __len21;      // distance(__middle, __m2)
44003e519524SHoward Hinnant        // binary search smaller range
44013e519524SHoward Hinnant        if (__len1 < __len2)
44023e519524SHoward Hinnant        {   // __len >= 1, __len2 >= 2
44033e519524SHoward Hinnant            __len21 = __len2 / 2;
44043e519524SHoward Hinnant            __m2 = __middle;
4405ce48a113SHoward Hinnant            _VSTD::advance(__m2, __len21);
44063e519524SHoward Hinnant            __m1 = __upper_bound<_Compare>(__first, __middle, *__m2, __comp);
4407ce48a113SHoward Hinnant            __len11 = _VSTD::distance(__first, __m1);
44083e519524SHoward Hinnant        }
44093e519524SHoward Hinnant        else
44103e519524SHoward Hinnant        {
44113e519524SHoward Hinnant            if (__len1 == 1)
44123e519524SHoward Hinnant            {   // __len1 >= __len2 && __len2 > 0, therefore __len2 == 1
44133e519524SHoward Hinnant                // It is known *__first > *__middle
44143e519524SHoward Hinnant                swap(*__first, *__middle);
44153e519524SHoward Hinnant                return;
44163e519524SHoward Hinnant            }
44173e519524SHoward Hinnant            // __len1 >= 2, __len2 >= 1
44183e519524SHoward Hinnant            __len11 = __len1 / 2;
44193e519524SHoward Hinnant            __m1 = __first;
4420ce48a113SHoward Hinnant            _VSTD::advance(__m1, __len11);
44213e519524SHoward Hinnant            __m2 = __lower_bound<_Compare>(__middle, __last, *__m1, __comp);
4422ce48a113SHoward Hinnant            __len21 = _VSTD::distance(__middle, __m2);
44233e519524SHoward Hinnant        }
44243e519524SHoward Hinnant        difference_type __len12 = __len1 - __len11;  // distance(__m1, __middle)
44253e519524SHoward Hinnant        difference_type __len22 = __len2 - __len21;  // distance(__m2, __last)
44263e519524SHoward Hinnant        // [__first, __m1) [__m1, __middle) [__middle, __m2) [__m2, __last)
44273e519524SHoward Hinnant        // swap middle two partitions
4428ce48a113SHoward Hinnant        __middle = _VSTD::rotate(__m1, __middle, __m2);
44293e519524SHoward Hinnant        // __len12 and __len21 now have swapped meanings
44303e519524SHoward Hinnant        // merge smaller range with recurisve call and larger with tail recursion elimination
44313e519524SHoward Hinnant        if (__len11 + __len21 < __len12 + __len22)
44323e519524SHoward Hinnant        {
44333e519524SHoward Hinnant            __inplace_merge<_Compare>(__first, __m1, __middle, __comp, __len11, __len21, __buff, __buff_size);
44343e519524SHoward Hinnant//          __inplace_merge<_Compare>(__middle, __m2, __last, __comp, __len12, __len22, __buff, __buff_size);
44353e519524SHoward Hinnant            __first = __middle;
44363e519524SHoward Hinnant            __middle = __m2;
44373e519524SHoward Hinnant            __len1 = __len12;
44383e519524SHoward Hinnant            __len2 = __len22;
44393e519524SHoward Hinnant        }
44403e519524SHoward Hinnant        else
44413e519524SHoward Hinnant        {
44423e519524SHoward Hinnant            __inplace_merge<_Compare>(__middle, __m2, __last, __comp, __len12, __len22, __buff, __buff_size);
44433e519524SHoward Hinnant//          __inplace_merge<_Compare>(__first, __m1, __middle, __comp, __len11, __len21, __buff, __buff_size);
44443e519524SHoward Hinnant            __last = __middle;
44453e519524SHoward Hinnant            __middle = __m1;
44463e519524SHoward Hinnant            __len1 = __len11;
44473e519524SHoward Hinnant            __len2 = __len21;
44483e519524SHoward Hinnant        }
44493e519524SHoward Hinnant    }
44503e519524SHoward Hinnant}
44513e519524SHoward Hinnant
44523e519524SHoward Hinnanttemplate <class _BidirectionalIterator, class _Compare>
44533e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
44543e519524SHoward Hinnantvoid
44553e519524SHoward Hinnantinplace_merge(_BidirectionalIterator __first, _BidirectionalIterator __middle, _BidirectionalIterator __last,
44563e519524SHoward Hinnant              _Compare __comp)
44573e519524SHoward Hinnant{
44583e519524SHoward Hinnant    typedef typename iterator_traits<_BidirectionalIterator>::value_type value_type;
44593e519524SHoward Hinnant    typedef typename iterator_traits<_BidirectionalIterator>::difference_type difference_type;
4460ce48a113SHoward Hinnant    difference_type __len1 = _VSTD::distance(__first, __middle);
4461ce48a113SHoward Hinnant    difference_type __len2 = _VSTD::distance(__middle, __last);
4462ce48a113SHoward Hinnant    difference_type __buf_size = _VSTD::min(__len1, __len2);
44630b48cf9aSMarshall Clow    pair<value_type*, ptrdiff_t> __buf = _VSTD::get_temporary_buffer<value_type>(__buf_size);
44640b48cf9aSMarshall Clow    unique_ptr<value_type, __return_temporary_buffer> __h(__buf.first);
44650b48cf9aSMarshall Clow
4466145afa17SHoward Hinnant#ifdef _LIBCPP_DEBUG
44673e519524SHoward Hinnant    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
44683e519524SHoward Hinnant    __debug_less<_Compare> __c(__comp);
4469ce48a113SHoward Hinnant    return _VSTD::__inplace_merge<_Comp_ref>(__first, __middle, __last, __c, __len1, __len2,
44703e519524SHoward Hinnant                                            __buf.first, __buf.second);
4471145afa17SHoward Hinnant#else  // _LIBCPP_DEBUG
44723e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
4473ce48a113SHoward Hinnant    return _VSTD::__inplace_merge<_Comp_ref>(__first, __middle, __last, __comp, __len1, __len2,
44743e519524SHoward Hinnant                                            __buf.first, __buf.second);
4475145afa17SHoward Hinnant#endif  // _LIBCPP_DEBUG
44763e519524SHoward Hinnant}
44773e519524SHoward Hinnant
44783e519524SHoward Hinnanttemplate <class _BidirectionalIterator>
44793e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
44803e519524SHoward Hinnantvoid
44813e519524SHoward Hinnantinplace_merge(_BidirectionalIterator __first, _BidirectionalIterator __middle, _BidirectionalIterator __last)
44823e519524SHoward Hinnant{
4483ce48a113SHoward Hinnant    _VSTD::inplace_merge(__first, __middle, __last,
44843e519524SHoward Hinnant                        __less<typename iterator_traits<_BidirectionalIterator>::value_type>());
44853e519524SHoward Hinnant}
44863e519524SHoward Hinnant
44873e519524SHoward Hinnant// stable_sort
44883e519524SHoward Hinnant
44893e519524SHoward Hinnanttemplate <class _Compare, class _InputIterator1, class _InputIterator2>
44903e519524SHoward Hinnantvoid
44913e519524SHoward Hinnant__merge_move_construct(_InputIterator1 __first1, _InputIterator1 __last1,
44923e519524SHoward Hinnant        _InputIterator2 __first2, _InputIterator2 __last2,
44933e519524SHoward Hinnant        typename iterator_traits<_InputIterator1>::value_type* __result, _Compare __comp)
44943e519524SHoward Hinnant{
44953e519524SHoward Hinnant    typedef typename iterator_traits<_InputIterator1>::value_type value_type;
44963e519524SHoward Hinnant    __destruct_n __d(0);
44973e519524SHoward Hinnant    unique_ptr<value_type, __destruct_n&> __h(__result, __d);
44983e519524SHoward Hinnant    for (; true; ++__result)
44993e519524SHoward Hinnant    {
45003e519524SHoward Hinnant        if (__first1 == __last1)
45013e519524SHoward Hinnant        {
45023e519524SHoward Hinnant            for (; __first2 != __last2; ++__first2, ++__result, __d.__incr((value_type*)0))
4503ce48a113SHoward Hinnant                ::new (__result) value_type(_VSTD::move(*__first2));
45043e519524SHoward Hinnant            __h.release();
45053e519524SHoward Hinnant            return;
45063e519524SHoward Hinnant        }
45073e519524SHoward Hinnant        if (__first2 == __last2)
45083e519524SHoward Hinnant        {
45093e519524SHoward Hinnant            for (; __first1 != __last1; ++__first1, ++__result, __d.__incr((value_type*)0))
4510ce48a113SHoward Hinnant                ::new (__result) value_type(_VSTD::move(*__first1));
45113e519524SHoward Hinnant            __h.release();
45123e519524SHoward Hinnant            return;
45133e519524SHoward Hinnant        }
45143e519524SHoward Hinnant        if (__comp(*__first2, *__first1))
45153e519524SHoward Hinnant        {
4516ce48a113SHoward Hinnant            ::new (__result) value_type(_VSTD::move(*__first2));
45173e519524SHoward Hinnant            __d.__incr((value_type*)0);
45183e519524SHoward Hinnant            ++__first2;
45193e519524SHoward Hinnant        }
45203e519524SHoward Hinnant        else
45213e519524SHoward Hinnant        {
4522ce48a113SHoward Hinnant            ::new (__result) value_type(_VSTD::move(*__first1));
45233e519524SHoward Hinnant            __d.__incr((value_type*)0);
45243e519524SHoward Hinnant            ++__first1;
45253e519524SHoward Hinnant        }
45263e519524SHoward Hinnant    }
45273e519524SHoward Hinnant}
45283e519524SHoward Hinnant
45293e519524SHoward Hinnanttemplate <class _Compare, class _InputIterator1, class _InputIterator2, class _OutputIterator>
45303e519524SHoward Hinnantvoid
45313e519524SHoward Hinnant__merge_move_assign(_InputIterator1 __first1, _InputIterator1 __last1,
45323e519524SHoward Hinnant        _InputIterator2 __first2, _InputIterator2 __last2,
45333e519524SHoward Hinnant        _OutputIterator __result, _Compare __comp)
45343e519524SHoward Hinnant{
45353e519524SHoward Hinnant    for (; __first1 != __last1; ++__result)
45363e519524SHoward Hinnant    {
45373e519524SHoward Hinnant        if (__first2 == __last2)
45383e519524SHoward Hinnant        {
45393e519524SHoward Hinnant            for (; __first1 != __last1; ++__first1, ++__result)
4540ce48a113SHoward Hinnant                *__result = _VSTD::move(*__first1);
45413e519524SHoward Hinnant            return;
45423e519524SHoward Hinnant        }
45433e519524SHoward Hinnant        if (__comp(*__first2, *__first1))
45443e519524SHoward Hinnant        {
4545ce48a113SHoward Hinnant            *__result = _VSTD::move(*__first2);
45463e519524SHoward Hinnant            ++__first2;
45473e519524SHoward Hinnant        }
45483e519524SHoward Hinnant        else
45493e519524SHoward Hinnant        {
4550ce48a113SHoward Hinnant            *__result = _VSTD::move(*__first1);
45513e519524SHoward Hinnant            ++__first1;
45523e519524SHoward Hinnant        }
45533e519524SHoward Hinnant    }
45543e519524SHoward Hinnant    for (; __first2 != __last2; ++__first2, ++__result)
4555ce48a113SHoward Hinnant        *__result = _VSTD::move(*__first2);
45563e519524SHoward Hinnant}
45573e519524SHoward Hinnant
45583e519524SHoward Hinnanttemplate <class _Compare, class _RandomAccessIterator>
45593e519524SHoward Hinnantvoid
45603e519524SHoward Hinnant__stable_sort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp,
45613e519524SHoward Hinnant              typename iterator_traits<_RandomAccessIterator>::difference_type __len,
45623e519524SHoward Hinnant              typename iterator_traits<_RandomAccessIterator>::value_type* __buff, ptrdiff_t __buff_size);
45633e519524SHoward Hinnant
45643e519524SHoward Hinnanttemplate <class _Compare, class _RandomAccessIterator>
45653e519524SHoward Hinnantvoid
45663e519524SHoward Hinnant__stable_sort_move(_RandomAccessIterator __first1, _RandomAccessIterator __last1, _Compare __comp,
45673e519524SHoward Hinnant                   typename iterator_traits<_RandomAccessIterator>::difference_type __len,
45683e519524SHoward Hinnant                   typename iterator_traits<_RandomAccessIterator>::value_type* __first2)
45693e519524SHoward Hinnant{
45703e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
45713e519524SHoward Hinnant    switch (__len)
45723e519524SHoward Hinnant    {
45733e519524SHoward Hinnant    case 0:
45743e519524SHoward Hinnant        return;
45753e519524SHoward Hinnant    case 1:
4576ce48a113SHoward Hinnant        ::new(__first2) value_type(_VSTD::move(*__first1));
45773e519524SHoward Hinnant        return;
45783e519524SHoward Hinnant    case 2:
45793e519524SHoward Hinnant        __destruct_n __d(0);
45803e519524SHoward Hinnant        unique_ptr<value_type, __destruct_n&> __h2(__first2, __d);
45813e519524SHoward Hinnant        if (__comp(*--__last1, *__first1))
45823e519524SHoward Hinnant        {
4583ce48a113SHoward Hinnant            ::new(__first2) value_type(_VSTD::move(*__last1));
45843e519524SHoward Hinnant            __d.__incr((value_type*)0);
45853e519524SHoward Hinnant            ++__first2;
4586ce48a113SHoward Hinnant            ::new(__first2) value_type(_VSTD::move(*__first1));
45873e519524SHoward Hinnant        }
45883e519524SHoward Hinnant        else
45893e519524SHoward Hinnant        {
4590ce48a113SHoward Hinnant            ::new(__first2) value_type(_VSTD::move(*__first1));
45913e519524SHoward Hinnant            __d.__incr((value_type*)0);
45923e519524SHoward Hinnant            ++__first2;
4593ce48a113SHoward Hinnant            ::new(__first2) value_type(_VSTD::move(*__last1));
45943e519524SHoward Hinnant        }
45953e519524SHoward Hinnant        __h2.release();
45963e519524SHoward Hinnant        return;
45973e519524SHoward Hinnant    }
45983e519524SHoward Hinnant    if (__len <= 8)
45993e519524SHoward Hinnant    {
46003e519524SHoward Hinnant        __insertion_sort_move<_Compare>(__first1, __last1, __first2, __comp);
46013e519524SHoward Hinnant        return;
46023e519524SHoward Hinnant    }
46033e519524SHoward Hinnant    typename iterator_traits<_RandomAccessIterator>::difference_type __l2 = __len / 2;
46043e519524SHoward Hinnant    _RandomAccessIterator __m = __first1 + __l2;
46053e519524SHoward Hinnant    __stable_sort<_Compare>(__first1, __m, __comp, __l2, __first2, __l2);
46063e519524SHoward Hinnant    __stable_sort<_Compare>(__m, __last1, __comp, __len - __l2, __first2 + __l2, __len - __l2);
46073e519524SHoward Hinnant    __merge_move_construct<_Compare>(__first1, __m, __m, __last1, __first2, __comp);
46083e519524SHoward Hinnant}
46093e519524SHoward Hinnant
46103e519524SHoward Hinnanttemplate <class _Tp>
46113e519524SHoward Hinnantstruct __stable_sort_switch
46123e519524SHoward Hinnant{
4613ca740483SHoward Hinnant    static const unsigned value = 128*is_trivially_copy_assignable<_Tp>::value;
46143e519524SHoward Hinnant};
46153e519524SHoward Hinnant
46163e519524SHoward Hinnanttemplate <class _Compare, class _RandomAccessIterator>
46173e519524SHoward Hinnantvoid
46183e519524SHoward Hinnant__stable_sort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp,
46193e519524SHoward Hinnant              typename iterator_traits<_RandomAccessIterator>::difference_type __len,
46203e519524SHoward Hinnant              typename iterator_traits<_RandomAccessIterator>::value_type* __buff, ptrdiff_t __buff_size)
46213e519524SHoward Hinnant{
46223e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
46233e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
46243e519524SHoward Hinnant    switch (__len)
46253e519524SHoward Hinnant    {
46263e519524SHoward Hinnant    case 0:
46273e519524SHoward Hinnant    case 1:
46283e519524SHoward Hinnant        return;
46293e519524SHoward Hinnant    case 2:
46303e519524SHoward Hinnant        if (__comp(*--__last, *__first))
46313e519524SHoward Hinnant            swap(*__first, *__last);
46323e519524SHoward Hinnant        return;
46333e519524SHoward Hinnant    }
46343e519524SHoward Hinnant    if (__len <= static_cast<difference_type>(__stable_sort_switch<value_type>::value))
46353e519524SHoward Hinnant    {
46363e519524SHoward Hinnant        __insertion_sort<_Compare>(__first, __last, __comp);
46373e519524SHoward Hinnant        return;
46383e519524SHoward Hinnant    }
46393e519524SHoward Hinnant    typename iterator_traits<_RandomAccessIterator>::difference_type __l2 = __len / 2;
46403e519524SHoward Hinnant    _RandomAccessIterator __m = __first + __l2;
46413e519524SHoward Hinnant    if (__len <= __buff_size)
46423e519524SHoward Hinnant    {
46433e519524SHoward Hinnant        __destruct_n __d(0);
46443e519524SHoward Hinnant        unique_ptr<value_type, __destruct_n&> __h2(__buff, __d);
46453e519524SHoward Hinnant        __stable_sort_move<_Compare>(__first, __m, __comp, __l2, __buff);
46463e519524SHoward Hinnant        __d.__set(__l2, (value_type*)0);
46473e519524SHoward Hinnant        __stable_sort_move<_Compare>(__m, __last, __comp, __len - __l2, __buff + __l2);
46483e519524SHoward Hinnant        __d.__set(__len, (value_type*)0);
46493e519524SHoward Hinnant        __merge_move_assign<_Compare>(__buff, __buff + __l2, __buff + __l2, __buff + __len, __first, __comp);
46503e519524SHoward Hinnant//         __merge<_Compare>(move_iterator<value_type*>(__buff),
46513e519524SHoward Hinnant//                           move_iterator<value_type*>(__buff + __l2),
46523e519524SHoward Hinnant//                           move_iterator<_RandomAccessIterator>(__buff + __l2),
46533e519524SHoward Hinnant//                           move_iterator<_RandomAccessIterator>(__buff + __len),
46543e519524SHoward Hinnant//                           __first, __comp);
46553e519524SHoward Hinnant        return;
46563e519524SHoward Hinnant    }
46573e519524SHoward Hinnant    __stable_sort<_Compare>(__first, __m, __comp, __l2, __buff, __buff_size);
46583e519524SHoward Hinnant    __stable_sort<_Compare>(__m, __last, __comp, __len - __l2, __buff, __buff_size);
46593e519524SHoward Hinnant    __inplace_merge<_Compare>(__first, __m, __last, __comp, __l2, __len - __l2, __buff, __buff_size);
46603e519524SHoward Hinnant}
46613e519524SHoward Hinnant
46623e519524SHoward Hinnanttemplate <class _RandomAccessIterator, class _Compare>
46633e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
46643e519524SHoward Hinnantvoid
46653e519524SHoward Hinnantstable_sort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
46663e519524SHoward Hinnant{
46673e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
46683e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
46693e519524SHoward Hinnant    difference_type __len = __last - __first;
46703e519524SHoward Hinnant    pair<value_type*, ptrdiff_t> __buf(0, 0);
46713e519524SHoward Hinnant    unique_ptr<value_type, __return_temporary_buffer> __h;
46723e519524SHoward Hinnant    if (__len > static_cast<difference_type>(__stable_sort_switch<value_type>::value))
46733e519524SHoward Hinnant    {
4674ce48a113SHoward Hinnant        __buf = _VSTD::get_temporary_buffer<value_type>(__len);
46753e519524SHoward Hinnant        __h.reset(__buf.first);
46763e519524SHoward Hinnant    }
4677145afa17SHoward Hinnant#ifdef _LIBCPP_DEBUG
46783e519524SHoward Hinnant    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
46793e519524SHoward Hinnant    __debug_less<_Compare> __c(__comp);
46803e519524SHoward Hinnant    __stable_sort<_Comp_ref>(__first, __last, __c, __len, __buf.first, __buf.second);
4681145afa17SHoward Hinnant#else  // _LIBCPP_DEBUG
46823e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
46833e519524SHoward Hinnant    __stable_sort<_Comp_ref>(__first, __last, __comp, __len, __buf.first, __buf.second);
4684145afa17SHoward Hinnant#endif  // _LIBCPP_DEBUG
46853e519524SHoward Hinnant}
46863e519524SHoward Hinnant
46873e519524SHoward Hinnanttemplate <class _RandomAccessIterator>
46883e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
46893e519524SHoward Hinnantvoid
46903e519524SHoward Hinnantstable_sort(_RandomAccessIterator __first, _RandomAccessIterator __last)
46913e519524SHoward Hinnant{
4692ce48a113SHoward Hinnant    _VSTD::stable_sort(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
46933e519524SHoward Hinnant}
46943e519524SHoward Hinnant
46953e519524SHoward Hinnant// is_heap_until
46963e519524SHoward Hinnant
46973e519524SHoward Hinnanttemplate <class _RandomAccessIterator, class _Compare>
469849c7643cSMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 _RandomAccessIterator
46993e519524SHoward Hinnantis_heap_until(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
47003e519524SHoward Hinnant{
4701ce48a113SHoward Hinnant    typedef typename _VSTD::iterator_traits<_RandomAccessIterator>::difference_type difference_type;
47023e519524SHoward Hinnant    difference_type __len = __last - __first;
47033e519524SHoward Hinnant    difference_type __p = 0;
47043e519524SHoward Hinnant    difference_type __c = 1;
47053e519524SHoward Hinnant    _RandomAccessIterator __pp = __first;
47063e519524SHoward Hinnant    while (__c < __len)
47073e519524SHoward Hinnant    {
47083e519524SHoward Hinnant        _RandomAccessIterator __cp = __first + __c;
47093e519524SHoward Hinnant        if (__comp(*__pp, *__cp))
47103e519524SHoward Hinnant            return __cp;
47113e519524SHoward Hinnant        ++__c;
47123e519524SHoward Hinnant        ++__cp;
47133e519524SHoward Hinnant        if (__c == __len)
47143e519524SHoward Hinnant            return __last;
47153e519524SHoward Hinnant        if (__comp(*__pp, *__cp))
47163e519524SHoward Hinnant            return __cp;
47173e519524SHoward Hinnant        ++__p;
47183e519524SHoward Hinnant        ++__pp;
47193e519524SHoward Hinnant        __c = 2 * __p + 1;
47203e519524SHoward Hinnant    }
47213e519524SHoward Hinnant    return __last;
47223e519524SHoward Hinnant}
47233e519524SHoward Hinnant
47243e519524SHoward Hinnanttemplate<class _RandomAccessIterator>
472549c7643cSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
47263e519524SHoward Hinnant_RandomAccessIterator
47273e519524SHoward Hinnantis_heap_until(_RandomAccessIterator __first, _RandomAccessIterator __last)
47283e519524SHoward Hinnant{
4729ce48a113SHoward Hinnant    return _VSTD::is_heap_until(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
47303e519524SHoward Hinnant}
47313e519524SHoward Hinnant
47323e519524SHoward Hinnant// is_heap
47333e519524SHoward Hinnant
47343e519524SHoward Hinnanttemplate <class _RandomAccessIterator, class _Compare>
473549c7643cSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
47363e519524SHoward Hinnantbool
47373e519524SHoward Hinnantis_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
47383e519524SHoward Hinnant{
4739ce48a113SHoward Hinnant    return _VSTD::is_heap_until(__first, __last, __comp) == __last;
47403e519524SHoward Hinnant}
47413e519524SHoward Hinnant
47423e519524SHoward Hinnanttemplate<class _RandomAccessIterator>
474349c7643cSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
47443e519524SHoward Hinnantbool
47453e519524SHoward Hinnantis_heap(_RandomAccessIterator __first, _RandomAccessIterator __last)
47463e519524SHoward Hinnant{
4747ce48a113SHoward Hinnant    return _VSTD::is_heap(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
47483e519524SHoward Hinnant}
47493e519524SHoward Hinnant
47503e519524SHoward Hinnant// push_heap
47513e519524SHoward Hinnant
47523e519524SHoward Hinnanttemplate <class _Compare, class _RandomAccessIterator>
47533e519524SHoward Hinnantvoid
47548b512602SDavid Majnemer__sift_up(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp,
47553e519524SHoward Hinnant          typename iterator_traits<_RandomAccessIterator>::difference_type __len)
47563e519524SHoward Hinnant{
47573e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
47583e519524SHoward Hinnant    if (__len > 1)
47593e519524SHoward Hinnant    {
47603e519524SHoward Hinnant        __len = (__len - 2) / 2;
47613e519524SHoward Hinnant        _RandomAccessIterator __ptr = __first + __len;
47623e519524SHoward Hinnant        if (__comp(*__ptr, *--__last))
47633e519524SHoward Hinnant        {
4764ce48a113SHoward Hinnant            value_type __t(_VSTD::move(*__last));
47653e519524SHoward Hinnant            do
47663e519524SHoward Hinnant            {
4767ce48a113SHoward Hinnant                *__last = _VSTD::move(*__ptr);
47683e519524SHoward Hinnant                __last = __ptr;
47693e519524SHoward Hinnant                if (__len == 0)
47703e519524SHoward Hinnant                    break;
47713e519524SHoward Hinnant                __len = (__len - 1) / 2;
47723e519524SHoward Hinnant                __ptr = __first + __len;
47733e519524SHoward Hinnant            } while (__comp(*__ptr, __t));
4774ce48a113SHoward Hinnant            *__last = _VSTD::move(__t);
47753e519524SHoward Hinnant        }
47763e519524SHoward Hinnant    }
47773e519524SHoward Hinnant}
47783e519524SHoward Hinnant
47793e519524SHoward Hinnanttemplate <class _RandomAccessIterator, class _Compare>
47803e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
47813e519524SHoward Hinnantvoid
47823e519524SHoward Hinnantpush_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
47833e519524SHoward Hinnant{
4784145afa17SHoward Hinnant#ifdef _LIBCPP_DEBUG
47853e519524SHoward Hinnant    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
47863e519524SHoward Hinnant    __debug_less<_Compare> __c(__comp);
47878b512602SDavid Majnemer    __sift_up<_Comp_ref>(__first, __last, __c, __last - __first);
4788145afa17SHoward Hinnant#else  // _LIBCPP_DEBUG
47893e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
47908b512602SDavid Majnemer    __sift_up<_Comp_ref>(__first, __last, __comp, __last - __first);
4791145afa17SHoward Hinnant#endif  // _LIBCPP_DEBUG
47923e519524SHoward Hinnant}
47933e519524SHoward Hinnant
47943e519524SHoward Hinnanttemplate <class _RandomAccessIterator>
47953e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
47963e519524SHoward Hinnantvoid
47973e519524SHoward Hinnantpush_heap(_RandomAccessIterator __first, _RandomAccessIterator __last)
47983e519524SHoward Hinnant{
4799ce48a113SHoward Hinnant    _VSTD::push_heap(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
48003e519524SHoward Hinnant}
48013e519524SHoward Hinnant
48023e519524SHoward Hinnant// pop_heap
48033e519524SHoward Hinnant
48043e519524SHoward Hinnanttemplate <class _Compare, class _RandomAccessIterator>
48058b512602SDavid Majnemervoid
4806fd838227SEric Fiselier__sift_down(_RandomAccessIterator __first, _RandomAccessIterator /*__last*/,
4807fd838227SEric Fiselier            _Compare __comp,
48088b512602SDavid Majnemer            typename iterator_traits<_RandomAccessIterator>::difference_type __len,
48098b512602SDavid Majnemer            _RandomAccessIterator __start)
48108b512602SDavid Majnemer{
48118b512602SDavid Majnemer    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
48128b512602SDavid Majnemer    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
48138b512602SDavid Majnemer    // left-child of __start is at 2 * __start + 1
48148b512602SDavid Majnemer    // right-child of __start is at 2 * __start + 2
48158b512602SDavid Majnemer    difference_type __child = __start - __first;
48168b512602SDavid Majnemer
48178b512602SDavid Majnemer    if (__len < 2 || (__len - 2) / 2 < __child)
48188b512602SDavid Majnemer        return;
48198b512602SDavid Majnemer
48208b512602SDavid Majnemer    __child = 2 * __child + 1;
48218b512602SDavid Majnemer    _RandomAccessIterator __child_i = __first + __child;
48228b512602SDavid Majnemer
48238b512602SDavid Majnemer    if ((__child + 1) < __len && __comp(*__child_i, *(__child_i + 1))) {
48248b512602SDavid Majnemer        // right-child exists and is greater than left-child
48258b512602SDavid Majnemer        ++__child_i;
48268b512602SDavid Majnemer        ++__child;
48278b512602SDavid Majnemer    }
48288b512602SDavid Majnemer
48298b512602SDavid Majnemer    // check if we are in heap-order
48308b512602SDavid Majnemer    if (__comp(*__child_i, *__start))
48318b512602SDavid Majnemer        // we are, __start is larger than it's largest child
48328b512602SDavid Majnemer        return;
48338b512602SDavid Majnemer
48348b512602SDavid Majnemer    value_type __top(_VSTD::move(*__start));
48358b512602SDavid Majnemer    do
48368b512602SDavid Majnemer    {
48378b512602SDavid Majnemer        // we are not in heap-order, swap the parent with it's largest child
48388b512602SDavid Majnemer        *__start = _VSTD::move(*__child_i);
48398b512602SDavid Majnemer        __start = __child_i;
48408b512602SDavid Majnemer
48418b512602SDavid Majnemer        if ((__len - 2) / 2 < __child)
48428b512602SDavid Majnemer            break;
48438b512602SDavid Majnemer
48448b512602SDavid Majnemer        // recompute the child based off of the updated parent
48458b512602SDavid Majnemer        __child = 2 * __child + 1;
48468b512602SDavid Majnemer        __child_i = __first + __child;
48478b512602SDavid Majnemer
48488b512602SDavid Majnemer        if ((__child + 1) < __len && __comp(*__child_i, *(__child_i + 1))) {
48498b512602SDavid Majnemer            // right-child exists and is greater than left-child
48508b512602SDavid Majnemer            ++__child_i;
48518b512602SDavid Majnemer            ++__child;
48528b512602SDavid Majnemer        }
48538b512602SDavid Majnemer
48548b512602SDavid Majnemer        // check if we are in heap-order
48558b512602SDavid Majnemer    } while (!__comp(*__child_i, __top));
48568b512602SDavid Majnemer    *__start = _VSTD::move(__top);
48578b512602SDavid Majnemer}
48588b512602SDavid Majnemer
48598b512602SDavid Majnemertemplate <class _Compare, class _RandomAccessIterator>
48603e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
48613e519524SHoward Hinnantvoid
48623e519524SHoward Hinnant__pop_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp,
48633e519524SHoward Hinnant           typename iterator_traits<_RandomAccessIterator>::difference_type __len)
48643e519524SHoward Hinnant{
48653e519524SHoward Hinnant    if (__len > 1)
48663e519524SHoward Hinnant    {
48673e519524SHoward Hinnant        swap(*__first, *--__last);
48688b512602SDavid Majnemer        __sift_down<_Compare>(__first, __last, __comp, __len - 1, __first);
48693e519524SHoward Hinnant    }
48703e519524SHoward Hinnant}
48713e519524SHoward Hinnant
48723e519524SHoward Hinnanttemplate <class _RandomAccessIterator, class _Compare>
48733e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
48743e519524SHoward Hinnantvoid
48753e519524SHoward Hinnantpop_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
48763e519524SHoward Hinnant{
4877145afa17SHoward Hinnant#ifdef _LIBCPP_DEBUG
48783e519524SHoward Hinnant    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
48793e519524SHoward Hinnant    __debug_less<_Compare> __c(__comp);
48803e519524SHoward Hinnant    __pop_heap<_Comp_ref>(__first, __last, __c, __last - __first);
4881145afa17SHoward Hinnant#else  // _LIBCPP_DEBUG
48823e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
48833e519524SHoward Hinnant    __pop_heap<_Comp_ref>(__first, __last, __comp, __last - __first);
4884145afa17SHoward Hinnant#endif  // _LIBCPP_DEBUG
48853e519524SHoward Hinnant}
48863e519524SHoward Hinnant
48873e519524SHoward Hinnanttemplate <class _RandomAccessIterator>
48883e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
48893e519524SHoward Hinnantvoid
48903e519524SHoward Hinnantpop_heap(_RandomAccessIterator __first, _RandomAccessIterator __last)
48913e519524SHoward Hinnant{
4892ce48a113SHoward Hinnant    _VSTD::pop_heap(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
48933e519524SHoward Hinnant}
48943e519524SHoward Hinnant
48953e519524SHoward Hinnant// make_heap
48963e519524SHoward Hinnant
48973e519524SHoward Hinnanttemplate <class _Compare, class _RandomAccessIterator>
48983e519524SHoward Hinnantvoid
48993e519524SHoward Hinnant__make_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
49003e519524SHoward Hinnant{
49013e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
49023e519524SHoward Hinnant    difference_type __n = __last - __first;
49033e519524SHoward Hinnant    if (__n > 1)
49043e519524SHoward Hinnant    {
49058b512602SDavid Majnemer        // start from the first parent, there is no need to consider children
49068b512602SDavid Majnemer        for (difference_type __start = (__n - 2) / 2; __start >= 0; --__start)
49078b512602SDavid Majnemer        {
49088b512602SDavid Majnemer            __sift_down<_Compare>(__first, __last, __comp, __n, __first + __start);
49098b512602SDavid Majnemer        }
49103e519524SHoward Hinnant    }
49113e519524SHoward Hinnant}
49123e519524SHoward Hinnant
49133e519524SHoward Hinnanttemplate <class _RandomAccessIterator, class _Compare>
49143e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
49153e519524SHoward Hinnantvoid
49163e519524SHoward Hinnantmake_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
49173e519524SHoward Hinnant{
4918145afa17SHoward Hinnant#ifdef _LIBCPP_DEBUG
49193e519524SHoward Hinnant    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
49203e519524SHoward Hinnant    __debug_less<_Compare> __c(__comp);
49213e519524SHoward Hinnant    __make_heap<_Comp_ref>(__first, __last, __c);
4922145afa17SHoward Hinnant#else  // _LIBCPP_DEBUG
49233e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
49243e519524SHoward Hinnant    __make_heap<_Comp_ref>(__first, __last, __comp);
4925145afa17SHoward Hinnant#endif  // _LIBCPP_DEBUG
49263e519524SHoward Hinnant}
49273e519524SHoward Hinnant
49283e519524SHoward Hinnanttemplate <class _RandomAccessIterator>
49293e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
49303e519524SHoward Hinnantvoid
49313e519524SHoward Hinnantmake_heap(_RandomAccessIterator __first, _RandomAccessIterator __last)
49323e519524SHoward Hinnant{
4933ce48a113SHoward Hinnant    _VSTD::make_heap(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
49343e519524SHoward Hinnant}
49353e519524SHoward Hinnant
49363e519524SHoward Hinnant// sort_heap
49373e519524SHoward Hinnant
49383e519524SHoward Hinnanttemplate <class _Compare, class _RandomAccessIterator>
49393e519524SHoward Hinnantvoid
49403e519524SHoward Hinnant__sort_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
49413e519524SHoward Hinnant{
49423e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
49433e519524SHoward Hinnant    for (difference_type __n = __last - __first; __n > 1; --__last, --__n)
49443e519524SHoward Hinnant        __pop_heap<_Compare>(__first, __last, __comp, __n);
49453e519524SHoward Hinnant}
49463e519524SHoward Hinnant
49473e519524SHoward Hinnanttemplate <class _RandomAccessIterator, class _Compare>
49483e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
49493e519524SHoward Hinnantvoid
49503e519524SHoward Hinnantsort_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
49513e519524SHoward Hinnant{
4952145afa17SHoward Hinnant#ifdef _LIBCPP_DEBUG
49533e519524SHoward Hinnant    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
49543e519524SHoward Hinnant    __debug_less<_Compare> __c(__comp);
49553e519524SHoward Hinnant    __sort_heap<_Comp_ref>(__first, __last, __c);
4956145afa17SHoward Hinnant#else  // _LIBCPP_DEBUG
49573e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
49583e519524SHoward Hinnant    __sort_heap<_Comp_ref>(__first, __last, __comp);
4959145afa17SHoward Hinnant#endif  // _LIBCPP_DEBUG
49603e519524SHoward Hinnant}
49613e519524SHoward Hinnant
49623e519524SHoward Hinnanttemplate <class _RandomAccessIterator>
49633e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
49643e519524SHoward Hinnantvoid
49653e519524SHoward Hinnantsort_heap(_RandomAccessIterator __first, _RandomAccessIterator __last)
49663e519524SHoward Hinnant{
4967ce48a113SHoward Hinnant    _VSTD::sort_heap(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
49683e519524SHoward Hinnant}
49693e519524SHoward Hinnant
49703e519524SHoward Hinnant// partial_sort
49713e519524SHoward Hinnant
49723e519524SHoward Hinnanttemplate <class _Compare, class _RandomAccessIterator>
49733e519524SHoward Hinnantvoid
49743e519524SHoward Hinnant__partial_sort(_RandomAccessIterator __first, _RandomAccessIterator __middle, _RandomAccessIterator __last,
49753e519524SHoward Hinnant             _Compare __comp)
49763e519524SHoward Hinnant{
49773e519524SHoward Hinnant    __make_heap<_Compare>(__first, __middle, __comp);
49783e519524SHoward Hinnant    typename iterator_traits<_RandomAccessIterator>::difference_type __len = __middle - __first;
49793e519524SHoward Hinnant    for (_RandomAccessIterator __i = __middle; __i != __last; ++__i)
49803e519524SHoward Hinnant    {
49813e519524SHoward Hinnant        if (__comp(*__i, *__first))
49823e519524SHoward Hinnant        {
49833e519524SHoward Hinnant            swap(*__i, *__first);
49848b512602SDavid Majnemer            __sift_down<_Compare>(__first, __middle, __comp, __len, __first);
49853e519524SHoward Hinnant        }
49863e519524SHoward Hinnant    }
49873e519524SHoward Hinnant    __sort_heap<_Compare>(__first, __middle, __comp);
49883e519524SHoward Hinnant}
49893e519524SHoward Hinnant
49903e519524SHoward Hinnanttemplate <class _RandomAccessIterator, class _Compare>
49913e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
49923e519524SHoward Hinnantvoid
49933e519524SHoward Hinnantpartial_sort(_RandomAccessIterator __first, _RandomAccessIterator __middle, _RandomAccessIterator __last,
49943e519524SHoward Hinnant             _Compare __comp)
49953e519524SHoward Hinnant{
4996145afa17SHoward Hinnant#ifdef _LIBCPP_DEBUG
49973e519524SHoward Hinnant    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
49983e519524SHoward Hinnant    __debug_less<_Compare> __c(__comp);
49993e519524SHoward Hinnant    __partial_sort<_Comp_ref>(__first, __middle, __last, __c);
5000145afa17SHoward Hinnant#else  // _LIBCPP_DEBUG
50013e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
50023e519524SHoward Hinnant    __partial_sort<_Comp_ref>(__first, __middle, __last, __comp);
5003145afa17SHoward Hinnant#endif  // _LIBCPP_DEBUG
50043e519524SHoward Hinnant}
50053e519524SHoward Hinnant
50063e519524SHoward Hinnanttemplate <class _RandomAccessIterator>
50073e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
50083e519524SHoward Hinnantvoid
50093e519524SHoward Hinnantpartial_sort(_RandomAccessIterator __first, _RandomAccessIterator __middle, _RandomAccessIterator __last)
50103e519524SHoward Hinnant{
5011ce48a113SHoward Hinnant    _VSTD::partial_sort(__first, __middle, __last,
50123e519524SHoward Hinnant                       __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
50133e519524SHoward Hinnant}
50143e519524SHoward Hinnant
50153e519524SHoward Hinnant// partial_sort_copy
50163e519524SHoward Hinnant
50173e519524SHoward Hinnanttemplate <class _Compare, class _InputIterator, class _RandomAccessIterator>
50183e519524SHoward Hinnant_RandomAccessIterator
50193e519524SHoward Hinnant__partial_sort_copy(_InputIterator __first, _InputIterator __last,
50203e519524SHoward Hinnant                    _RandomAccessIterator __result_first, _RandomAccessIterator __result_last, _Compare __comp)
50213e519524SHoward Hinnant{
50223e519524SHoward Hinnant    _RandomAccessIterator __r = __result_first;
50233e519524SHoward Hinnant    if (__r != __result_last)
50243e519524SHoward Hinnant    {
5025910285b2SEric Fiselier        for (; __first != __last && __r != __result_last; (void) ++__first, ++__r)
50263e519524SHoward Hinnant            *__r = *__first;
50273e519524SHoward Hinnant        __make_heap<_Compare>(__result_first, __r, __comp);
50288b512602SDavid Majnemer        typename iterator_traits<_RandomAccessIterator>::difference_type __len = __r - __result_first;
50293e519524SHoward Hinnant        for (; __first != __last; ++__first)
50303e519524SHoward Hinnant            if (__comp(*__first, *__result_first))
50313e519524SHoward Hinnant            {
50323e519524SHoward Hinnant                *__result_first = *__first;
50338b512602SDavid Majnemer                __sift_down<_Compare>(__result_first, __r, __comp, __len, __result_first);
50343e519524SHoward Hinnant            }
50353e519524SHoward Hinnant        __sort_heap<_Compare>(__result_first, __r, __comp);
50363e519524SHoward Hinnant    }
50373e519524SHoward Hinnant    return __r;
50383e519524SHoward Hinnant}
50393e519524SHoward Hinnant
50403e519524SHoward Hinnanttemplate <class _InputIterator, class _RandomAccessIterator, class _Compare>
50413e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
50423e519524SHoward Hinnant_RandomAccessIterator
50433e519524SHoward Hinnantpartial_sort_copy(_InputIterator __first, _InputIterator __last,
50443e519524SHoward Hinnant                  _RandomAccessIterator __result_first, _RandomAccessIterator __result_last, _Compare __comp)
50453e519524SHoward Hinnant{
5046145afa17SHoward Hinnant#ifdef _LIBCPP_DEBUG
50473e519524SHoward Hinnant    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
50483e519524SHoward Hinnant    __debug_less<_Compare> __c(__comp);
50493e519524SHoward Hinnant    return __partial_sort_copy<_Comp_ref>(__first, __last, __result_first, __result_last, __c);
5050145afa17SHoward Hinnant#else  // _LIBCPP_DEBUG
50513e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
50523e519524SHoward Hinnant    return __partial_sort_copy<_Comp_ref>(__first, __last, __result_first, __result_last, __comp);
5053145afa17SHoward Hinnant#endif  // _LIBCPP_DEBUG
50543e519524SHoward Hinnant}
50553e519524SHoward Hinnant
50563e519524SHoward Hinnanttemplate <class _InputIterator, class _RandomAccessIterator>
50573e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
50583e519524SHoward Hinnant_RandomAccessIterator
50593e519524SHoward Hinnantpartial_sort_copy(_InputIterator __first, _InputIterator __last,
50603e519524SHoward Hinnant                  _RandomAccessIterator __result_first, _RandomAccessIterator __result_last)
50613e519524SHoward Hinnant{
5062ce48a113SHoward Hinnant    return _VSTD::partial_sort_copy(__first, __last, __result_first, __result_last,
50633e519524SHoward Hinnant                                   __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
50643e519524SHoward Hinnant}
50653e519524SHoward Hinnant
50663e519524SHoward Hinnant// nth_element
50673e519524SHoward Hinnant
50683e519524SHoward Hinnanttemplate <class _Compare, class _RandomAccessIterator>
50693e519524SHoward Hinnantvoid
50703e519524SHoward Hinnant__nth_element(_RandomAccessIterator __first, _RandomAccessIterator __nth, _RandomAccessIterator __last, _Compare __comp)
50713e519524SHoward Hinnant{
50723e519524SHoward Hinnant    // _Compare is known to be a reference type
50733e519524SHoward Hinnant    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
50743e519524SHoward Hinnant    const difference_type __limit = 7;
50753e519524SHoward Hinnant    while (true)
50763e519524SHoward Hinnant    {
50773e519524SHoward Hinnant    __restart:
5078b34b4819SHoward Hinnant        if (__nth == __last)
5079b34b4819SHoward Hinnant            return;
50803e519524SHoward Hinnant        difference_type __len = __last - __first;
50813e519524SHoward Hinnant        switch (__len)
50823e519524SHoward Hinnant        {
50833e519524SHoward Hinnant        case 0:
50843e519524SHoward Hinnant        case 1:
50853e519524SHoward Hinnant            return;
50863e519524SHoward Hinnant        case 2:
50873e519524SHoward Hinnant            if (__comp(*--__last, *__first))
50883e519524SHoward Hinnant                swap(*__first, *__last);
50893e519524SHoward Hinnant            return;
50903e519524SHoward Hinnant        case 3:
50913e519524SHoward Hinnant            {
50923e519524SHoward Hinnant            _RandomAccessIterator __m = __first;
5093ce48a113SHoward Hinnant            _VSTD::__sort3<_Compare>(__first, ++__m, --__last, __comp);
50943e519524SHoward Hinnant            return;
50953e519524SHoward Hinnant            }
50963e519524SHoward Hinnant        }
50973e519524SHoward Hinnant        if (__len <= __limit)
50983e519524SHoward Hinnant        {
50993e519524SHoward Hinnant            __selection_sort<_Compare>(__first, __last, __comp);
51003e519524SHoward Hinnant            return;
51013e519524SHoward Hinnant        }
51023e519524SHoward Hinnant        // __len > __limit >= 3
51033e519524SHoward Hinnant        _RandomAccessIterator __m = __first + __len/2;
51043e519524SHoward Hinnant        _RandomAccessIterator __lm1 = __last;
5105ce48a113SHoward Hinnant        unsigned __n_swaps = _VSTD::__sort3<_Compare>(__first, __m, --__lm1, __comp);
51063e519524SHoward Hinnant        // *__m is median
51073e519524SHoward Hinnant        // partition [__first, __m) < *__m and *__m <= [__m, __last)
51083e519524SHoward Hinnant        // (this inhibits tossing elements equivalent to __m around unnecessarily)
51093e519524SHoward Hinnant        _RandomAccessIterator __i = __first;
51103e519524SHoward Hinnant        _RandomAccessIterator __j = __lm1;
51113e519524SHoward Hinnant        // j points beyond range to be tested, *__lm1 is known to be <= *__m
51123e519524SHoward Hinnant        // The search going up is known to be guarded but the search coming down isn't.
51133e519524SHoward Hinnant        // Prime the downward search with a guard.
51143e519524SHoward Hinnant        if (!__comp(*__i, *__m))  // if *__first == *__m
51153e519524SHoward Hinnant        {
51163e519524SHoward Hinnant            // *__first == *__m, *__first doesn't go in first part
51173e519524SHoward Hinnant            // manually guard downward moving __j against __i
51183e519524SHoward Hinnant            while (true)
51193e519524SHoward Hinnant            {
51203e519524SHoward Hinnant                if (__i == --__j)
51213e519524SHoward Hinnant                {
51223e519524SHoward Hinnant                    // *__first == *__m, *__m <= all other elements
51233e519524SHoward Hinnant                    // Parition instead into [__first, __i) == *__first and *__first < [__i, __last)
51243e519524SHoward Hinnant                    ++__i;  // __first + 1
51253e519524SHoward Hinnant                    __j = __last;
51263e519524SHoward Hinnant                    if (!__comp(*__first, *--__j))  // we need a guard if *__first == *(__last-1)
51273e519524SHoward Hinnant                    {
51283e519524SHoward Hinnant                        while (true)
51293e519524SHoward Hinnant                        {
51303e519524SHoward Hinnant                            if (__i == __j)
51313e519524SHoward Hinnant                                return;  // [__first, __last) all equivalent elements
51323e519524SHoward Hinnant                            if (__comp(*__first, *__i))
51333e519524SHoward Hinnant                            {
51343e519524SHoward Hinnant                                swap(*__i, *__j);
51353e519524SHoward Hinnant                                ++__n_swaps;
51363e519524SHoward Hinnant                                ++__i;
51373e519524SHoward Hinnant                                break;
51383e519524SHoward Hinnant                            }
51393e519524SHoward Hinnant                            ++__i;
51403e519524SHoward Hinnant                        }
51413e519524SHoward Hinnant                    }
51423e519524SHoward Hinnant                    // [__first, __i) == *__first and *__first < [__j, __last) and __j == __last - 1
51433e519524SHoward Hinnant                    if (__i == __j)
51443e519524SHoward Hinnant                        return;
51453e519524SHoward Hinnant                    while (true)
51463e519524SHoward Hinnant                    {
51473e519524SHoward Hinnant                        while (!__comp(*__first, *__i))
51483e519524SHoward Hinnant                            ++__i;
51493e519524SHoward Hinnant                        while (__comp(*__first, *--__j))
51503e519524SHoward Hinnant                            ;
51513e519524SHoward Hinnant                        if (__i >= __j)
51523e519524SHoward Hinnant                            break;
51533e519524SHoward Hinnant                        swap(*__i, *__j);
51543e519524SHoward Hinnant                        ++__n_swaps;
51553e519524SHoward Hinnant                        ++__i;
51563e519524SHoward Hinnant                    }
51573e519524SHoward Hinnant                    // [__first, __i) == *__first and *__first < [__i, __last)
51583e519524SHoward Hinnant                    // The first part is sorted,
51593e519524SHoward Hinnant                    if (__nth < __i)
51603e519524SHoward Hinnant                        return;
51613e519524SHoward Hinnant                    // __nth_element the secod part
51623e519524SHoward Hinnant                    // __nth_element<_Compare>(__i, __nth, __last, __comp);
51633e519524SHoward Hinnant                    __first = __i;
51643e519524SHoward Hinnant                    goto __restart;
51653e519524SHoward Hinnant                }
51663e519524SHoward Hinnant                if (__comp(*__j, *__m))
51673e519524SHoward Hinnant                {
51683e519524SHoward Hinnant                    swap(*__i, *__j);
51693e519524SHoward Hinnant                    ++__n_swaps;
51703e519524SHoward Hinnant                    break;  // found guard for downward moving __j, now use unguarded partition
51713e519524SHoward Hinnant                }
51723e519524SHoward Hinnant            }
51733e519524SHoward Hinnant        }
51743e519524SHoward Hinnant        ++__i;
51753e519524SHoward Hinnant        // j points beyond range to be tested, *__lm1 is known to be <= *__m
51763e519524SHoward Hinnant        // if not yet partitioned...
51773e519524SHoward Hinnant        if (__i < __j)
51783e519524SHoward Hinnant        {
51793e519524SHoward Hinnant            // known that *(__i - 1) < *__m
51803e519524SHoward Hinnant            while (true)
51813e519524SHoward Hinnant            {
51823e519524SHoward Hinnant                // __m still guards upward moving __i
51833e519524SHoward Hinnant                while (__comp(*__i, *__m))
51843e519524SHoward Hinnant                    ++__i;
51853e519524SHoward Hinnant                // It is now known that a guard exists for downward moving __j
51863e519524SHoward Hinnant                while (!__comp(*--__j, *__m))
51873e519524SHoward Hinnant                    ;
51883e519524SHoward Hinnant                if (__i >= __j)
51893e519524SHoward Hinnant                    break;
51903e519524SHoward Hinnant                swap(*__i, *__j);
51913e519524SHoward Hinnant                ++__n_swaps;
51923e519524SHoward Hinnant                // It is known that __m != __j
51933e519524SHoward Hinnant                // If __m just moved, follow it
51943e519524SHoward Hinnant                if (__m == __i)
51953e519524SHoward Hinnant                    __m = __j;
51963e519524SHoward Hinnant                ++__i;
51973e519524SHoward Hinnant            }
51983e519524SHoward Hinnant        }
51993e519524SHoward Hinnant        // [__first, __i) < *__m and *__m <= [__i, __last)
52003e519524SHoward Hinnant        if (__i != __m && __comp(*__m, *__i))
52013e519524SHoward Hinnant        {
52023e519524SHoward Hinnant            swap(*__i, *__m);
52033e519524SHoward Hinnant            ++__n_swaps;
52043e519524SHoward Hinnant        }
52053e519524SHoward Hinnant        // [__first, __i) < *__i and *__i <= [__i+1, __last)
52063e519524SHoward Hinnant        if (__nth == __i)
52073e519524SHoward Hinnant            return;
52083e519524SHoward Hinnant        if (__n_swaps == 0)
52093e519524SHoward Hinnant        {
52103e519524SHoward Hinnant            // We were given a perfectly partitioned sequence.  Coincidence?
52113e519524SHoward Hinnant            if (__nth < __i)
52123e519524SHoward Hinnant            {
52133e519524SHoward Hinnant                // Check for [__first, __i) already sorted
52143e519524SHoward Hinnant                __j = __m = __first;
52153e519524SHoward Hinnant                while (++__j != __i)
52163e519524SHoward Hinnant                {
52173e519524SHoward Hinnant                    if (__comp(*__j, *__m))
52183e519524SHoward Hinnant                        // not yet sorted, so sort
52193e519524SHoward Hinnant                        goto not_sorted;
52203e519524SHoward Hinnant                    __m = __j;
52213e519524SHoward Hinnant                }
52223e519524SHoward Hinnant                // [__first, __i) sorted
52233e519524SHoward Hinnant                return;
52243e519524SHoward Hinnant            }
52253e519524SHoward Hinnant            else
52263e519524SHoward Hinnant            {
52273e519524SHoward Hinnant                // Check for [__i, __last) already sorted
52283e519524SHoward Hinnant                __j = __m = __i;
52293e519524SHoward Hinnant                while (++__j != __last)
52303e519524SHoward Hinnant                {
52313e519524SHoward Hinnant                    if (__comp(*__j, *__m))
52323e519524SHoward Hinnant                        // not yet sorted, so sort
52333e519524SHoward Hinnant                        goto not_sorted;
52343e519524SHoward Hinnant                    __m = __j;
52353e519524SHoward Hinnant                }
52363e519524SHoward Hinnant                // [__i, __last) sorted
52373e519524SHoward Hinnant                return;
52383e519524SHoward Hinnant            }
52393e519524SHoward Hinnant        }
52403e519524SHoward Hinnantnot_sorted:
52413e519524SHoward Hinnant        // __nth_element on range containing __nth
52423e519524SHoward Hinnant        if (__nth < __i)
52433e519524SHoward Hinnant        {
52443e519524SHoward Hinnant            // __nth_element<_Compare>(__first, __nth, __i, __comp);
52453e519524SHoward Hinnant            __last = __i;
52463e519524SHoward Hinnant        }
52473e519524SHoward Hinnant        else
52483e519524SHoward Hinnant        {
52493e519524SHoward Hinnant            // __nth_element<_Compare>(__i+1, __nth, __last, __comp);
52503e519524SHoward Hinnant            __first = ++__i;
52513e519524SHoward Hinnant        }
52523e519524SHoward Hinnant    }
52533e519524SHoward Hinnant}
52543e519524SHoward Hinnant
52553e519524SHoward Hinnanttemplate <class _RandomAccessIterator, class _Compare>
52563e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
52573e519524SHoward Hinnantvoid
52583e519524SHoward Hinnantnth_element(_RandomAccessIterator __first, _RandomAccessIterator __nth, _RandomAccessIterator __last, _Compare __comp)
52593e519524SHoward Hinnant{
5260145afa17SHoward Hinnant#ifdef _LIBCPP_DEBUG
52613e519524SHoward Hinnant    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
52623e519524SHoward Hinnant    __debug_less<_Compare> __c(__comp);
52633e519524SHoward Hinnant    __nth_element<_Comp_ref>(__first, __nth, __last, __c);
5264145afa17SHoward Hinnant#else  // _LIBCPP_DEBUG
52653e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
52663e519524SHoward Hinnant    __nth_element<_Comp_ref>(__first, __nth, __last, __comp);
5267145afa17SHoward Hinnant#endif  // _LIBCPP_DEBUG
52683e519524SHoward Hinnant}
52693e519524SHoward Hinnant
52703e519524SHoward Hinnanttemplate <class _RandomAccessIterator>
52713e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
52723e519524SHoward Hinnantvoid
52733e519524SHoward Hinnantnth_element(_RandomAccessIterator __first, _RandomAccessIterator __nth, _RandomAccessIterator __last)
52743e519524SHoward Hinnant{
5275ce48a113SHoward Hinnant    _VSTD::nth_element(__first, __nth, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
52763e519524SHoward Hinnant}
52773e519524SHoward Hinnant
52783e519524SHoward Hinnant// includes
52793e519524SHoward Hinnant
52803e519524SHoward Hinnanttemplate <class _Compare, class _InputIterator1, class _InputIterator2>
52818da1a487SMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
52823e519524SHoward Hinnant__includes(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2,
52833e519524SHoward Hinnant           _Compare __comp)
52843e519524SHoward Hinnant{
52853e519524SHoward Hinnant    for (; __first2 != __last2; ++__first1)
52863e519524SHoward Hinnant    {
52873e519524SHoward Hinnant        if (__first1 == __last1 || __comp(*__first2, *__first1))
52883e519524SHoward Hinnant            return false;
52893e519524SHoward Hinnant        if (!__comp(*__first1, *__first2))
52903e519524SHoward Hinnant            ++__first2;
52913e519524SHoward Hinnant    }
52923e519524SHoward Hinnant    return true;
52933e519524SHoward Hinnant}
52943e519524SHoward Hinnant
52953e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _Compare>
52968da1a487SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
52973e519524SHoward Hinnantbool
52983e519524SHoward Hinnantincludes(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2,
52993e519524SHoward Hinnant         _Compare __comp)
53003e519524SHoward Hinnant{
5301145afa17SHoward Hinnant#ifdef _LIBCPP_DEBUG
53023e519524SHoward Hinnant    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
53033e519524SHoward Hinnant    __debug_less<_Compare> __c(__comp);
53043e519524SHoward Hinnant    return __includes<_Comp_ref>(__first1, __last1, __first2, __last2, __c);
5305145afa17SHoward Hinnant#else  // _LIBCPP_DEBUG
53063e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
53073e519524SHoward Hinnant    return __includes<_Comp_ref>(__first1, __last1, __first2, __last2, __comp);
5308145afa17SHoward Hinnant#endif  // _LIBCPP_DEBUG
53093e519524SHoward Hinnant}
53103e519524SHoward Hinnant
53113e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2>
53128da1a487SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
53133e519524SHoward Hinnantbool
53143e519524SHoward Hinnantincludes(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2)
53153e519524SHoward Hinnant{
5316ce48a113SHoward Hinnant    return _VSTD::includes(__first1, __last1, __first2, __last2,
53173e519524SHoward Hinnant                          __less<typename iterator_traits<_InputIterator1>::value_type,
53183e519524SHoward Hinnant                                 typename iterator_traits<_InputIterator2>::value_type>());
53193e519524SHoward Hinnant}
53203e519524SHoward Hinnant
53213e519524SHoward Hinnant// set_union
53223e519524SHoward Hinnant
53233e519524SHoward Hinnanttemplate <class _Compare, class _InputIterator1, class _InputIterator2, class _OutputIterator>
53243e519524SHoward Hinnant_OutputIterator
53253e519524SHoward Hinnant__set_union(_InputIterator1 __first1, _InputIterator1 __last1,
53263e519524SHoward Hinnant            _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
53273e519524SHoward Hinnant{
53283e519524SHoward Hinnant    for (; __first1 != __last1; ++__result)
53293e519524SHoward Hinnant    {
53303e519524SHoward Hinnant        if (__first2 == __last2)
5331ce48a113SHoward Hinnant            return _VSTD::copy(__first1, __last1, __result);
53323e519524SHoward Hinnant        if (__comp(*__first2, *__first1))
53333e519524SHoward Hinnant        {
53343e519524SHoward Hinnant            *__result = *__first2;
53353e519524SHoward Hinnant            ++__first2;
53363e519524SHoward Hinnant        }
53373e519524SHoward Hinnant        else
53383e519524SHoward Hinnant        {
53393e519524SHoward Hinnant            if (!__comp(*__first1, *__first2))
53403e519524SHoward Hinnant                ++__first2;
534105da5b02SMarshall Clow            *__result = *__first1;
53423e519524SHoward Hinnant            ++__first1;
53433e519524SHoward Hinnant        }
53443e519524SHoward Hinnant    }
5345ce48a113SHoward Hinnant    return _VSTD::copy(__first2, __last2, __result);
53463e519524SHoward Hinnant}
53473e519524SHoward Hinnant
53483e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
53493e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
53503e519524SHoward Hinnant_OutputIterator
53513e519524SHoward Hinnantset_union(_InputIterator1 __first1, _InputIterator1 __last1,
53523e519524SHoward Hinnant          _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
53533e519524SHoward Hinnant{
5354145afa17SHoward Hinnant#ifdef _LIBCPP_DEBUG
53553e519524SHoward Hinnant    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
53563e519524SHoward Hinnant    __debug_less<_Compare> __c(__comp);
53573e519524SHoward Hinnant    return __set_union<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __c);
5358145afa17SHoward Hinnant#else  // _LIBCPP_DEBUG
53593e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
53603e519524SHoward Hinnant    return __set_union<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __comp);
5361145afa17SHoward Hinnant#endif  // _LIBCPP_DEBUG
53623e519524SHoward Hinnant}
53633e519524SHoward Hinnant
53643e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _OutputIterator>
53653e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
53663e519524SHoward Hinnant_OutputIterator
53673e519524SHoward Hinnantset_union(_InputIterator1 __first1, _InputIterator1 __last1,
53683e519524SHoward Hinnant          _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result)
53693e519524SHoward Hinnant{
5370ce48a113SHoward Hinnant    return _VSTD::set_union(__first1, __last1, __first2, __last2, __result,
53713e519524SHoward Hinnant                          __less<typename iterator_traits<_InputIterator1>::value_type,
53723e519524SHoward Hinnant                                 typename iterator_traits<_InputIterator2>::value_type>());
53733e519524SHoward Hinnant}
53743e519524SHoward Hinnant
53753e519524SHoward Hinnant// set_intersection
53763e519524SHoward Hinnant
53773e519524SHoward Hinnanttemplate <class _Compare, class _InputIterator1, class _InputIterator2, class _OutputIterator>
53788da1a487SMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 _OutputIterator
53793e519524SHoward Hinnant__set_intersection(_InputIterator1 __first1, _InputIterator1 __last1,
53803e519524SHoward Hinnant                   _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
53813e519524SHoward Hinnant{
53823e519524SHoward Hinnant    while (__first1 != __last1 && __first2 != __last2)
53833e519524SHoward Hinnant    {
53843e519524SHoward Hinnant        if (__comp(*__first1, *__first2))
53853e519524SHoward Hinnant            ++__first1;
53863e519524SHoward Hinnant        else
53873e519524SHoward Hinnant        {
53883e519524SHoward Hinnant            if (!__comp(*__first2, *__first1))
53893e519524SHoward Hinnant            {
53903e519524SHoward Hinnant                *__result = *__first1;
53913e519524SHoward Hinnant                ++__result;
53923e519524SHoward Hinnant                ++__first1;
53933e519524SHoward Hinnant            }
53943e519524SHoward Hinnant            ++__first2;
53953e519524SHoward Hinnant        }
53963e519524SHoward Hinnant    }
53973e519524SHoward Hinnant    return __result;
53983e519524SHoward Hinnant}
53993e519524SHoward Hinnant
54003e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
54018da1a487SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
54023e519524SHoward Hinnant_OutputIterator
54033e519524SHoward Hinnantset_intersection(_InputIterator1 __first1, _InputIterator1 __last1,
54043e519524SHoward Hinnant                 _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
54053e519524SHoward Hinnant{
5406145afa17SHoward Hinnant#ifdef _LIBCPP_DEBUG
54073e519524SHoward Hinnant    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
54083e519524SHoward Hinnant    __debug_less<_Compare> __c(__comp);
54093e519524SHoward Hinnant    return __set_intersection<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __c);
5410145afa17SHoward Hinnant#else  // _LIBCPP_DEBUG
54113e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
54123e519524SHoward Hinnant    return __set_intersection<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __comp);
5413145afa17SHoward Hinnant#endif  // _LIBCPP_DEBUG
54143e519524SHoward Hinnant}
54153e519524SHoward Hinnant
54163e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _OutputIterator>
54178da1a487SMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
54183e519524SHoward Hinnant_OutputIterator
54193e519524SHoward Hinnantset_intersection(_InputIterator1 __first1, _InputIterator1 __last1,
54203e519524SHoward Hinnant                 _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result)
54213e519524SHoward Hinnant{
5422ce48a113SHoward Hinnant    return _VSTD::set_intersection(__first1, __last1, __first2, __last2, __result,
54233e519524SHoward Hinnant                                  __less<typename iterator_traits<_InputIterator1>::value_type,
54243e519524SHoward Hinnant                                         typename iterator_traits<_InputIterator2>::value_type>());
54253e519524SHoward Hinnant}
54263e519524SHoward Hinnant
54273e519524SHoward Hinnant// set_difference
54283e519524SHoward Hinnant
54293e519524SHoward Hinnanttemplate <class _Compare, class _InputIterator1, class _InputIterator2, class _OutputIterator>
54303e519524SHoward Hinnant_OutputIterator
54313e519524SHoward Hinnant__set_difference(_InputIterator1 __first1, _InputIterator1 __last1,
54323e519524SHoward Hinnant                 _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
54333e519524SHoward Hinnant{
54343e519524SHoward Hinnant    while (__first1 != __last1)
54353e519524SHoward Hinnant    {
54363e519524SHoward Hinnant        if (__first2 == __last2)
5437ce48a113SHoward Hinnant            return _VSTD::copy(__first1, __last1, __result);
54383e519524SHoward Hinnant        if (__comp(*__first1, *__first2))
54393e519524SHoward Hinnant        {
54403e519524SHoward Hinnant            *__result = *__first1;
54413e519524SHoward Hinnant            ++__result;
54423e519524SHoward Hinnant            ++__first1;
54433e519524SHoward Hinnant        }
54443e519524SHoward Hinnant        else
54453e519524SHoward Hinnant        {
54463e519524SHoward Hinnant            if (!__comp(*__first2, *__first1))
54473e519524SHoward Hinnant                ++__first1;
54483e519524SHoward Hinnant            ++__first2;
54493e519524SHoward Hinnant        }
54503e519524SHoward Hinnant    }
54513e519524SHoward Hinnant    return __result;
54523e519524SHoward Hinnant}
54533e519524SHoward Hinnant
54543e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
54553e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
54563e519524SHoward Hinnant_OutputIterator
54573e519524SHoward Hinnantset_difference(_InputIterator1 __first1, _InputIterator1 __last1,
54583e519524SHoward Hinnant               _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
54593e519524SHoward Hinnant{
5460145afa17SHoward Hinnant#ifdef _LIBCPP_DEBUG
54613e519524SHoward Hinnant    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
54623e519524SHoward Hinnant    __debug_less<_Compare> __c(__comp);
54633e519524SHoward Hinnant    return __set_difference<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __c);
5464145afa17SHoward Hinnant#else  // _LIBCPP_DEBUG
54653e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
54663e519524SHoward Hinnant    return __set_difference<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __comp);
5467145afa17SHoward Hinnant#endif  // _LIBCPP_DEBUG
54683e519524SHoward Hinnant}
54693e519524SHoward Hinnant
54703e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _OutputIterator>
54713e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
54723e519524SHoward Hinnant_OutputIterator
54733e519524SHoward Hinnantset_difference(_InputIterator1 __first1, _InputIterator1 __last1,
54743e519524SHoward Hinnant               _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result)
54753e519524SHoward Hinnant{
5476ce48a113SHoward Hinnant    return _VSTD::set_difference(__first1, __last1, __first2, __last2, __result,
54773e519524SHoward Hinnant                                __less<typename iterator_traits<_InputIterator1>::value_type,
54783e519524SHoward Hinnant                                       typename iterator_traits<_InputIterator2>::value_type>());
54793e519524SHoward Hinnant}
54803e519524SHoward Hinnant
54813e519524SHoward Hinnant// set_symmetric_difference
54823e519524SHoward Hinnant
54833e519524SHoward Hinnanttemplate <class _Compare, class _InputIterator1, class _InputIterator2, class _OutputIterator>
54843e519524SHoward Hinnant_OutputIterator
54853e519524SHoward Hinnant__set_symmetric_difference(_InputIterator1 __first1, _InputIterator1 __last1,
54863e519524SHoward Hinnant                           _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
54873e519524SHoward Hinnant{
54883e519524SHoward Hinnant    while (__first1 != __last1)
54893e519524SHoward Hinnant    {
54903e519524SHoward Hinnant        if (__first2 == __last2)
5491ce48a113SHoward Hinnant            return _VSTD::copy(__first1, __last1, __result);
54923e519524SHoward Hinnant        if (__comp(*__first1, *__first2))
54933e519524SHoward Hinnant        {
54943e519524SHoward Hinnant            *__result = *__first1;
54953e519524SHoward Hinnant            ++__result;
54963e519524SHoward Hinnant            ++__first1;
54973e519524SHoward Hinnant        }
54983e519524SHoward Hinnant        else
54993e519524SHoward Hinnant        {
55003e519524SHoward Hinnant            if (__comp(*__first2, *__first1))
55013e519524SHoward Hinnant            {
55023e519524SHoward Hinnant                *__result = *__first2;
55033e519524SHoward Hinnant                ++__result;
55043e519524SHoward Hinnant            }
55053e519524SHoward Hinnant            else
55063e519524SHoward Hinnant                ++__first1;
55073e519524SHoward Hinnant            ++__first2;
55083e519524SHoward Hinnant        }
55093e519524SHoward Hinnant    }
5510ce48a113SHoward Hinnant    return _VSTD::copy(__first2, __last2, __result);
55113e519524SHoward Hinnant}
55123e519524SHoward Hinnant
55133e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
55143e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
55153e519524SHoward Hinnant_OutputIterator
55163e519524SHoward Hinnantset_symmetric_difference(_InputIterator1 __first1, _InputIterator1 __last1,
55173e519524SHoward Hinnant                         _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
55183e519524SHoward Hinnant{
5519145afa17SHoward Hinnant#ifdef _LIBCPP_DEBUG
55203e519524SHoward Hinnant    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
55213e519524SHoward Hinnant    __debug_less<_Compare> __c(__comp);
55223e519524SHoward Hinnant    return __set_symmetric_difference<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __c);
5523145afa17SHoward Hinnant#else  // _LIBCPP_DEBUG
55243e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
55253e519524SHoward Hinnant    return __set_symmetric_difference<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __comp);
5526145afa17SHoward Hinnant#endif  // _LIBCPP_DEBUG
55273e519524SHoward Hinnant}
55283e519524SHoward Hinnant
55293e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _OutputIterator>
55303e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
55313e519524SHoward Hinnant_OutputIterator
55323e519524SHoward Hinnantset_symmetric_difference(_InputIterator1 __first1, _InputIterator1 __last1,
55333e519524SHoward Hinnant                         _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result)
55343e519524SHoward Hinnant{
5535ce48a113SHoward Hinnant    return _VSTD::set_symmetric_difference(__first1, __last1, __first2, __last2, __result,
55363e519524SHoward Hinnant                                          __less<typename iterator_traits<_InputIterator1>::value_type,
55373e519524SHoward Hinnant                                                 typename iterator_traits<_InputIterator2>::value_type>());
55383e519524SHoward Hinnant}
55393e519524SHoward Hinnant
55403e519524SHoward Hinnant// lexicographical_compare
55413e519524SHoward Hinnant
55423e519524SHoward Hinnanttemplate <class _Compare, class _InputIterator1, class _InputIterator2>
55431b9a4ffdSMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
55443e519524SHoward Hinnant__lexicographical_compare(_InputIterator1 __first1, _InputIterator1 __last1,
55453e519524SHoward Hinnant                          _InputIterator2 __first2, _InputIterator2 __last2, _Compare __comp)
55463e519524SHoward Hinnant{
5547910285b2SEric Fiselier    for (; __first2 != __last2; ++__first1, (void) ++__first2)
55483e519524SHoward Hinnant    {
55493e519524SHoward Hinnant        if (__first1 == __last1 || __comp(*__first1, *__first2))
55503e519524SHoward Hinnant            return true;
55513e519524SHoward Hinnant        if (__comp(*__first2, *__first1))
55523e519524SHoward Hinnant            return false;
55533e519524SHoward Hinnant    }
55543e519524SHoward Hinnant    return false;
55553e519524SHoward Hinnant}
55563e519524SHoward Hinnant
55573e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2, class _Compare>
55581b9a4ffdSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
55593e519524SHoward Hinnantbool
55603e519524SHoward Hinnantlexicographical_compare(_InputIterator1 __first1, _InputIterator1 __last1,
55613e519524SHoward Hinnant                        _InputIterator2 __first2, _InputIterator2 __last2, _Compare __comp)
55623e519524SHoward Hinnant{
5563145afa17SHoward Hinnant#ifdef _LIBCPP_DEBUG
55643e519524SHoward Hinnant    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
55653e519524SHoward Hinnant    __debug_less<_Compare> __c(__comp);
55663e519524SHoward Hinnant    return __lexicographical_compare<_Comp_ref>(__first1, __last1, __first2, __last2, __c);
5567145afa17SHoward Hinnant#else  // _LIBCPP_DEBUG
55683e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
55693e519524SHoward Hinnant    return __lexicographical_compare<_Comp_ref>(__first1, __last1, __first2, __last2, __comp);
5570145afa17SHoward Hinnant#endif  // _LIBCPP_DEBUG
55713e519524SHoward Hinnant}
55723e519524SHoward Hinnant
55733e519524SHoward Hinnanttemplate <class _InputIterator1, class _InputIterator2>
55741b9a4ffdSMarshall Clowinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
55753e519524SHoward Hinnantbool
55763e519524SHoward Hinnantlexicographical_compare(_InputIterator1 __first1, _InputIterator1 __last1,
55773e519524SHoward Hinnant                        _InputIterator2 __first2, _InputIterator2 __last2)
55783e519524SHoward Hinnant{
5579ce48a113SHoward Hinnant    return _VSTD::lexicographical_compare(__first1, __last1, __first2, __last2,
55803e519524SHoward Hinnant                                         __less<typename iterator_traits<_InputIterator1>::value_type,
55813e519524SHoward Hinnant                                                typename iterator_traits<_InputIterator2>::value_type>());
55823e519524SHoward Hinnant}
55833e519524SHoward Hinnant
55843e519524SHoward Hinnant// next_permutation
55853e519524SHoward Hinnant
55863e519524SHoward Hinnanttemplate <class _Compare, class _BidirectionalIterator>
55873e519524SHoward Hinnantbool
55883e519524SHoward Hinnant__next_permutation(_BidirectionalIterator __first, _BidirectionalIterator __last, _Compare __comp)
55893e519524SHoward Hinnant{
55903e519524SHoward Hinnant    _BidirectionalIterator __i = __last;
55913e519524SHoward Hinnant    if (__first == __last || __first == --__i)
55923e519524SHoward Hinnant        return false;
55933e519524SHoward Hinnant    while (true)
55943e519524SHoward Hinnant    {
55953e519524SHoward Hinnant        _BidirectionalIterator __ip1 = __i;
55963e519524SHoward Hinnant        if (__comp(*--__i, *__ip1))
55973e519524SHoward Hinnant        {
55983e519524SHoward Hinnant            _BidirectionalIterator __j = __last;
55993e519524SHoward Hinnant            while (!__comp(*__i, *--__j))
56003e519524SHoward Hinnant                ;
56013e519524SHoward Hinnant            swap(*__i, *__j);
5602ce48a113SHoward Hinnant            _VSTD::reverse(__ip1, __last);
56033e519524SHoward Hinnant            return true;
56043e519524SHoward Hinnant        }
56053e519524SHoward Hinnant        if (__i == __first)
56063e519524SHoward Hinnant        {
5607ce48a113SHoward Hinnant            _VSTD::reverse(__first, __last);
56083e519524SHoward Hinnant            return false;
56093e519524SHoward Hinnant        }
56103e519524SHoward Hinnant    }
56113e519524SHoward Hinnant}
56123e519524SHoward Hinnant
56133e519524SHoward Hinnanttemplate <class _BidirectionalIterator, class _Compare>
56143e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
56153e519524SHoward Hinnantbool
56163e519524SHoward Hinnantnext_permutation(_BidirectionalIterator __first, _BidirectionalIterator __last, _Compare __comp)
56173e519524SHoward Hinnant{
5618145afa17SHoward Hinnant#ifdef _LIBCPP_DEBUG
56193e519524SHoward Hinnant    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
56203e519524SHoward Hinnant    __debug_less<_Compare> __c(__comp);
56213e519524SHoward Hinnant    return __next_permutation<_Comp_ref>(__first, __last, __c);
5622145afa17SHoward Hinnant#else  // _LIBCPP_DEBUG
56233e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
56243e519524SHoward Hinnant    return __next_permutation<_Comp_ref>(__first, __last, __comp);
5625145afa17SHoward Hinnant#endif  // _LIBCPP_DEBUG
56263e519524SHoward Hinnant}
56273e519524SHoward Hinnant
56283e519524SHoward Hinnanttemplate <class _BidirectionalIterator>
56293e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
56303e519524SHoward Hinnantbool
56313e519524SHoward Hinnantnext_permutation(_BidirectionalIterator __first, _BidirectionalIterator __last)
56323e519524SHoward Hinnant{
5633ce48a113SHoward Hinnant    return _VSTD::next_permutation(__first, __last,
56343e519524SHoward Hinnant                                  __less<typename iterator_traits<_BidirectionalIterator>::value_type>());
56353e519524SHoward Hinnant}
56363e519524SHoward Hinnant
56373e519524SHoward Hinnant// prev_permutation
56383e519524SHoward Hinnant
56393e519524SHoward Hinnanttemplate <class _Compare, class _BidirectionalIterator>
56403e519524SHoward Hinnantbool
56413e519524SHoward Hinnant__prev_permutation(_BidirectionalIterator __first, _BidirectionalIterator __last, _Compare __comp)
56423e519524SHoward Hinnant{
56433e519524SHoward Hinnant    _BidirectionalIterator __i = __last;
56443e519524SHoward Hinnant    if (__first == __last || __first == --__i)
56453e519524SHoward Hinnant        return false;
56463e519524SHoward Hinnant    while (true)
56473e519524SHoward Hinnant    {
56483e519524SHoward Hinnant        _BidirectionalIterator __ip1 = __i;
56493e519524SHoward Hinnant        if (__comp(*__ip1, *--__i))
56503e519524SHoward Hinnant        {
56513e519524SHoward Hinnant            _BidirectionalIterator __j = __last;
56523e519524SHoward Hinnant            while (!__comp(*--__j, *__i))
56533e519524SHoward Hinnant                ;
56543e519524SHoward Hinnant            swap(*__i, *__j);
5655ce48a113SHoward Hinnant            _VSTD::reverse(__ip1, __last);
56563e519524SHoward Hinnant            return true;
56573e519524SHoward Hinnant        }
56583e519524SHoward Hinnant        if (__i == __first)
56593e519524SHoward Hinnant        {
5660ce48a113SHoward Hinnant            _VSTD::reverse(__first, __last);
56613e519524SHoward Hinnant            return false;
56623e519524SHoward Hinnant        }
56633e519524SHoward Hinnant    }
56643e519524SHoward Hinnant}
56653e519524SHoward Hinnant
56663e519524SHoward Hinnanttemplate <class _BidirectionalIterator, class _Compare>
56673e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
56683e519524SHoward Hinnantbool
56693e519524SHoward Hinnantprev_permutation(_BidirectionalIterator __first, _BidirectionalIterator __last, _Compare __comp)
56703e519524SHoward Hinnant{
5671145afa17SHoward Hinnant#ifdef _LIBCPP_DEBUG
56723e519524SHoward Hinnant    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
56733e519524SHoward Hinnant    __debug_less<_Compare> __c(__comp);
56743e519524SHoward Hinnant    return __prev_permutation<_Comp_ref>(__first, __last, __c);
5675145afa17SHoward Hinnant#else  // _LIBCPP_DEBUG
56763e519524SHoward Hinnant    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
56773e519524SHoward Hinnant    return __prev_permutation<_Comp_ref>(__first, __last, __comp);
5678145afa17SHoward Hinnant#endif  // _LIBCPP_DEBUG
56793e519524SHoward Hinnant}
56803e519524SHoward Hinnant
56813e519524SHoward Hinnanttemplate <class _BidirectionalIterator>
56823e519524SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
56833e519524SHoward Hinnantbool
56843e519524SHoward Hinnantprev_permutation(_BidirectionalIterator __first, _BidirectionalIterator __last)
56853e519524SHoward Hinnant{
5686ce48a113SHoward Hinnant    return _VSTD::prev_permutation(__first, __last,
56873e519524SHoward Hinnant                                  __less<typename iterator_traits<_BidirectionalIterator>::value_type>());
56883e519524SHoward Hinnant}
56893e519524SHoward Hinnant
56903e519524SHoward Hinnant_LIBCPP_END_NAMESPACE_STD
56913e519524SHoward Hinnant
5692a016efb1SEric Fiselier_LIBCPP_POP_MACROS
5693a016efb1SEric Fiselier
56943e519524SHoward Hinnant#endif  // _LIBCPP_ALGORITHM
5695