Remove libc++ and libc++abi 8.0.0 now that we switched to version 10.0.1

in the gnu/ directory.

1 files changed, 0 insertions, 5710 deletions

diff --git a/lib/libcxx/include/algorithm b/lib/libcxx/include/algorithm
deleted file mode 100644
index d102899f2df..00000000000
--- a/lib/libcxx/include/algorithm
+++ /dev/null
@@ -1,5710 +0,0 @@
-// -*- C++ -*-
-//===-------------------------- algorithm ---------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_ALGORITHM
-#define _LIBCPP_ALGORITHM
-
-/*
-    algorithm synopsis
-
-#include <initializer_list>
-
-namespace std
-{
-
-template <class InputIterator, class Predicate>
-    constexpr bool     // constexpr in C++20
-    all_of(InputIterator first, InputIterator last, Predicate pred);
-
-template <class InputIterator, class Predicate>
-    constexpr bool     // constexpr in C++20
-    any_of(InputIterator first, InputIterator last, Predicate pred);
-
-template <class InputIterator, class Predicate>
-    constexpr bool     // constexpr in C++20
-    none_of(InputIterator first, InputIterator last, Predicate pred);
-
-template <class InputIterator, class Function>
-    constexpr Function          // constexpr in C++20
-    for_each(InputIterator first, InputIterator last, Function f);
-
-template<class InputIterator, class Size, class Function>
-    constexpr InputIterator     // constexpr in C++20
-    for_each_n(InputIterator first, Size n, Function f); // C++17
-
-template <class InputIterator, class T>
-    constexpr InputIterator     // constexpr in C++20
-    find(InputIterator first, InputIterator last, const T& value);
-
-template <class InputIterator, class Predicate>
-    constexpr InputIterator     // constexpr in C++20
-    find_if(InputIterator first, InputIterator last, Predicate pred);
-
-template<class InputIterator, class Predicate>
-    InputIterator               // constexpr in C++20
-    find_if_not(InputIterator first, InputIterator last, Predicate pred);
-
-template <class ForwardIterator1, class ForwardIterator2>
-    ForwardIterator1            // constexpr in C++20
-    find_end(ForwardIterator1 first1, ForwardIterator1 last1,
-             ForwardIterator2 first2, ForwardIterator2 last2);
-
-template <class ForwardIterator1, class ForwardIterator2, class BinaryPredicate>
-    ForwardIterator1            // constexpr in C++20
-    find_end(ForwardIterator1 first1, ForwardIterator1 last1,
-             ForwardIterator2 first2, ForwardIterator2 last2, BinaryPredicate pred);
-
-template <class ForwardIterator1, class ForwardIterator2>
-    constexpr ForwardIterator1  // constexpr in C++20
-    find_first_of(ForwardIterator1 first1, ForwardIterator1 last1,
-                  ForwardIterator2 first2, ForwardIterator2 last2);
-
-template <class ForwardIterator1, class ForwardIterator2, class BinaryPredicate>
-    constexpr ForwardIterator1  // constexpr in C++20
-    find_first_of(ForwardIterator1 first1, ForwardIterator1 last1,
-                  ForwardIterator2 first2, ForwardIterator2 last2, BinaryPredicate pred);
-
-template <class ForwardIterator>
-    constexpr ForwardIterator   // constexpr in C++20
-    adjacent_find(ForwardIterator first, ForwardIterator last);
-
-template <class ForwardIterator, class BinaryPredicate>
-    constexpr ForwardIterator   // constexpr in C++20
-    adjacent_find(ForwardIterator first, ForwardIterator last, BinaryPredicate pred);
-
-template <class InputIterator, class T>
-    constexpr typename iterator_traits<InputIterator>::difference_type  // constexpr in C++20
-    count(InputIterator first, InputIterator last, const T& value);
-
-template <class InputIterator, class Predicate>
-    constexpr typename iterator_traits<InputIterator>::difference_type // constexpr in C++20
-    count_if(InputIterator first, InputIterator last, Predicate pred);
-
-template <class InputIterator1, class InputIterator2>
-    constexpr pair<InputIterator1, InputIterator2>   // constexpr in C++20
-    mismatch(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2);
-
-template <class InputIterator1, class InputIterator2>
-    constexpr pair<InputIterator1, InputIterator2>   // constexpr in C++20
-    mismatch(InputIterator1 first1, InputIterator1 last1,
-             InputIterator2 first2, InputIterator2 last2); // **C++14**
-
-template <class InputIterator1, class InputIterator2, class BinaryPredicate>
-    constexpr pair<InputIterator1, InputIterator2>   // constexpr in C++20
-    mismatch(InputIterator1 first1, InputIterator1 last1,
-             InputIterator2 first2, BinaryPredicate pred);
-
-template <class InputIterator1, class InputIterator2, class BinaryPredicate>
-    constexpr pair<InputIterator1, InputIterator2>   // constexpr in C++20
-    mismatch(InputIterator1 first1, InputIterator1 last1,
-             InputIterator2 first2, InputIterator2 last2,
-             BinaryPredicate pred); // **C++14**
-
-template <class InputIterator1, class InputIterator2>
-    constexpr bool      // constexpr in C++20
-    equal(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2);
-
-template <class InputIterator1, class InputIterator2>
-    constexpr bool      // constexpr in C++20
-    equal(InputIterator1 first1, InputIterator1 last1,
-          InputIterator2 first2, InputIterator2 last2); // **C++14**
-
-template <class InputIterator1, class InputIterator2, class BinaryPredicate>
-    constexpr bool      // constexpr in C++20
-    equal(InputIterator1 first1, InputIterator1 last1,
-          InputIterator2 first2, BinaryPredicate pred);
-
-template <class InputIterator1, class InputIterator2, class BinaryPredicate>
-    constexpr bool      // constexpr in C++20
-    equal(InputIterator1 first1, InputIterator1 last1,
-          InputIterator2 first2, InputIterator2 last2,
-          BinaryPredicate pred); // **C++14**
-
-template<class ForwardIterator1, class ForwardIterator2>
-    constexpr bool      // constexpr in C++20
-    is_permutation(ForwardIterator1 first1, ForwardIterator1 last1,
-                   ForwardIterator2 first2);
-
-template<class ForwardIterator1, class ForwardIterator2>
-    constexpr bool      // constexpr in C++20
-    is_permutation(ForwardIterator1 first1, ForwardIterator1 last1,
-                   ForwardIterator2 first2, ForwardIterator2 last2); // **C++14**
-
-template<class ForwardIterator1, class ForwardIterator2, class BinaryPredicate>
-    constexpr bool      // constexpr in C++20
-    is_permutation(ForwardIterator1 first1, ForwardIterator1 last1,
-                   ForwardIterator2 first2, BinaryPredicate pred);
-
-template<class ForwardIterator1, class ForwardIterator2, class BinaryPredicate>
-    constexpr bool      // constexpr in C++20
-    is_permutation(ForwardIterator1 first1, ForwardIterator1 last1,
-                   ForwardIterator2 first2, ForwardIterator2 last2,
-                   BinaryPredicate pred);  // **C++14**
-
-template <class ForwardIterator1, class ForwardIterator2>
-    constexpr ForwardIterator1      // constexpr in C++20
-    search(ForwardIterator1 first1, ForwardIterator1 last1,
-           ForwardIterator2 first2, ForwardIterator2 last2);
-
-template <class ForwardIterator1, class ForwardIterator2, class BinaryPredicate>
-    constexpr ForwardIterator1      // constexpr in C++20
-    search(ForwardIterator1 first1, ForwardIterator1 last1,
-           ForwardIterator2 first2, ForwardIterator2 last2, BinaryPredicate pred);
-
-template <class ForwardIterator, class Size, class T>
-    constexpr ForwardIterator       // constexpr in C++20
-    search_n(ForwardIterator first, ForwardIterator last, Size count, const T& value);
-
-template <class ForwardIterator, class Size, class T, class BinaryPredicate>
-    constexpr ForwardIterator       // constexpr in C++20
-    search_n(ForwardIterator first, ForwardIterator last,
-             Size count, const T& value, BinaryPredicate pred);
-
-template <class InputIterator, class OutputIterator>
-    OutputIterator
-    copy(InputIterator first, InputIterator last, OutputIterator result);
-
-template<class InputIterator, class OutputIterator, class Predicate>
-    OutputIterator
-    copy_if(InputIterator first, InputIterator last,
-            OutputIterator result, Predicate pred);
-
-template<class InputIterator, class Size, class OutputIterator>
-    OutputIterator
-    copy_n(InputIterator first, Size n, OutputIterator result);
-
-template <class BidirectionalIterator1, class BidirectionalIterator2>
-    BidirectionalIterator2
-    copy_backward(BidirectionalIterator1 first, BidirectionalIterator1 last,
-                  BidirectionalIterator2 result);
-
-template <class ForwardIterator1, class ForwardIterator2>
-    ForwardIterator2
-    swap_ranges(ForwardIterator1 first1, ForwardIterator1 last1, ForwardIterator2 first2);
-
-template <class ForwardIterator1, class ForwardIterator2>
-    void
-    iter_swap(ForwardIterator1 a, ForwardIterator2 b);
-
-template <class InputIterator, class OutputIterator, class UnaryOperation>
-    constexpr OutputIterator      // constexpr in C++20
-    transform(InputIterator first, InputIterator last, OutputIterator result, UnaryOperation op);
-
-template <class InputIterator1, class InputIterator2, class OutputIterator, class BinaryOperation>
-    constexpr OutputIterator      // constexpr in C++20
-    transform(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2,
-              OutputIterator result, BinaryOperation binary_op);
-
-template <class ForwardIterator, class T>
-    constexpr void      // constexpr in C++20
-    replace(ForwardIterator first, ForwardIterator last, const T& old_value, const T& new_value);
-
-template <class ForwardIterator, class Predicate, class T>
-    constexpr void      // constexpr in C++20
-    replace_if(ForwardIterator first, ForwardIterator last, Predicate pred, const T& new_value);
-
-template <class InputIterator, class OutputIterator, class T>
-    constexpr OutputIterator      // constexpr in C++20
-    replace_copy(InputIterator first, InputIterator last, OutputIterator result,
-                 const T& old_value, const T& new_value);
-
-template <class InputIterator, class OutputIterator, class Predicate, class T>
-    constexpr OutputIterator      // constexpr in C++20
-    replace_copy_if(InputIterator first, InputIterator last, OutputIterator result, Predicate pred, const T& new_value);
-
-template <class ForwardIterator, class T>
-    constexpr void      // constexpr in C++20
-    fill(ForwardIterator first, ForwardIterator last, const T& value);
-
-template <class OutputIterator, class Size, class T>
-    constexpr OutputIterator      // constexpr in C++20
-    fill_n(OutputIterator first, Size n, const T& value);
-
-template <class ForwardIterator, class Generator>
-    constexpr void      // constexpr in C++20
-    generate(ForwardIterator first, ForwardIterator last, Generator gen);
-
-template <class OutputIterator, class Size, class Generator>
-    constexpr OutputIterator      // constexpr in C++20
-    generate_n(OutputIterator first, Size n, Generator gen);
-
-template <class ForwardIterator, class T>
-    constexpr ForwardIterator     // constexpr in C++20
-    remove(ForwardIterator first, ForwardIterator last, const T& value);
-
-template <class ForwardIterator, class Predicate>
-    constexpr ForwardIterator     // constexpr in C++20
-    remove_if(ForwardIterator first, ForwardIterator last, Predicate pred);
-
-template <class InputIterator, class OutputIterator, class T>
-    constexpr OutputIterator     // constexpr in C++20
-    remove_copy(InputIterator first, InputIterator last, OutputIterator result, const T& value);
-
-template <class InputIterator, class OutputIterator, class Predicate>
-    constexpr OutputIterator     // constexpr in C++20
-    remove_copy_if(InputIterator first, InputIterator last, OutputIterator result, Predicate pred);
-
-template <class ForwardIterator>
-    ForwardIterator
-    unique(ForwardIterator first, ForwardIterator last);
-
-template <class ForwardIterator, class BinaryPredicate>
-    ForwardIterator
-    unique(ForwardIterator first, ForwardIterator last, BinaryPredicate pred);
-
-template <class InputIterator, class OutputIterator>
-    OutputIterator
-    unique_copy(InputIterator first, InputIterator last, OutputIterator result);
-
-template <class InputIterator, class OutputIterator, class BinaryPredicate>
-    OutputIterator
-    unique_copy(InputIterator first, InputIterator last, OutputIterator result, BinaryPredicate pred);
-
-template <class BidirectionalIterator>
-    void
-    reverse(BidirectionalIterator first, BidirectionalIterator last);
-
-template <class BidirectionalIterator, class OutputIterator>
-    constexpr OutputIterator       // constexpr in C++20
-    reverse_copy(BidirectionalIterator first, BidirectionalIterator last, OutputIterator result);
-
-template <class ForwardIterator>
-    ForwardIterator
-    rotate(ForwardIterator first, ForwardIterator middle, ForwardIterator last);
-
-template <class ForwardIterator, class OutputIterator>
-    OutputIterator
-    rotate_copy(ForwardIterator first, ForwardIterator middle, ForwardIterator last, OutputIterator result);
-
-template <class RandomAccessIterator>
-    void
-    random_shuffle(RandomAccessIterator first, RandomAccessIterator last); // deprecated in C++14, removed in C++17
-
-template <class RandomAccessIterator, class RandomNumberGenerator>
-    void
-    random_shuffle(RandomAccessIterator first, RandomAccessIterator last,
-                   RandomNumberGenerator& rand);  // deprecated in C++14, removed in C++17
-
-template<class PopulationIterator, class SampleIterator,
-         class Distance, class UniformRandomBitGenerator>
-    SampleIterator sample(PopulationIterator first, PopulationIterator last,
-                          SampleIterator out, Distance n,
-                          UniformRandomBitGenerator&& g); // C++17
-
-template<class RandomAccessIterator, class UniformRandomNumberGenerator>
-    void shuffle(RandomAccessIterator first, RandomAccessIterator last,
-                 UniformRandomNumberGenerator&& g);
-
-template <class InputIterator, class Predicate>
-    constexpr bool  // constexpr in C++20
-    is_partitioned(InputIterator first, InputIterator last, Predicate pred);
-
-template <class ForwardIterator, class Predicate>
-    ForwardIterator
-    partition(ForwardIterator first, ForwardIterator last, Predicate pred);
-
-template <class InputIterator, class OutputIterator1,
-          class OutputIterator2, class Predicate>
-    constexpr pair<OutputIterator1, OutputIterator2>   // constexpr in C++20
-    partition_copy(InputIterator first, InputIterator last,
-                   OutputIterator1 out_true, OutputIterator2 out_false,
-                   Predicate pred);
-
-template <class ForwardIterator, class Predicate>
-    ForwardIterator
-    stable_partition(ForwardIterator first, ForwardIterator last, Predicate pred);
-
-template<class ForwardIterator, class Predicate>
-    constexpr ForwardIterator  // constexpr in C++20
-    partition_point(ForwardIterator first, ForwardIterator last, Predicate pred);
-
-template <class ForwardIterator>
-    constexpr bool  // constexpr in C++20
-    is_sorted(ForwardIterator first, ForwardIterator last);
-
-template <class ForwardIterator, class Compare>
-    bool
-    is_sorted(ForwardIterator first, ForwardIterator last, Compare comp);
-
-template<class ForwardIterator>
-    constexpr ForwardIterator    // constexpr in C++20
-    is_sorted_until(ForwardIterator first, ForwardIterator last);
-
-template <class ForwardIterator, class Compare>
-    constexpr ForwardIterator    // constexpr in C++20
-    is_sorted_until(ForwardIterator first, ForwardIterator last, Compare comp);
-
-template <class RandomAccessIterator>
-    void
-    sort(RandomAccessIterator first, RandomAccessIterator last);
-
-template <class RandomAccessIterator, class Compare>
-    void
-    sort(RandomAccessIterator first, RandomAccessIterator last, Compare comp);
-
-template <class RandomAccessIterator>
-    void
-    stable_sort(RandomAccessIterator first, RandomAccessIterator last);
-
-template <class RandomAccessIterator, class Compare>
-    void
-    stable_sort(RandomAccessIterator first, RandomAccessIterator last, Compare comp);
-
-template <class RandomAccessIterator>
-    void
-    partial_sort(RandomAccessIterator first, RandomAccessIterator middle, RandomAccessIterator last);
-
-template <class RandomAccessIterator, class Compare>
-    void
-    partial_sort(RandomAccessIterator first, RandomAccessIterator middle, RandomAccessIterator last, Compare comp);
-
-template <class InputIterator, class RandomAccessIterator>
-    RandomAccessIterator
-    partial_sort_copy(InputIterator first, InputIterator last,
-                      RandomAccessIterator result_first, RandomAccessIterator result_last);
-
-template <class InputIterator, class RandomAccessIterator, class Compare>
-    RandomAccessIterator
-    partial_sort_copy(InputIterator first, InputIterator last,
-                      RandomAccessIterator result_first, RandomAccessIterator result_last, Compare comp);
-
-template <class RandomAccessIterator>
-    void
-    nth_element(RandomAccessIterator first, RandomAccessIterator nth, RandomAccessIterator last);
-
-template <class RandomAccessIterator, class Compare>
-    void
-    nth_element(RandomAccessIterator first, RandomAccessIterator nth, RandomAccessIterator last, Compare comp);
-
-template <class ForwardIterator, class T>
-    constexpr ForwardIterator                         // constexpr in C++20
-    lower_bound(ForwardIterator first, ForwardIterator last, const T& value);
-
-template <class ForwardIterator, class T, class Compare>
-    constexpr ForwardIterator                         // constexpr in C++20
-    lower_bound(ForwardIterator first, ForwardIterator last, const T& value, Compare comp);
-
-template <class ForwardIterator, class T>
-    constexpr ForwardIterator                         // constexpr in C++20
-    upper_bound(ForwardIterator first, ForwardIterator last, const T& value);
-
-template <class ForwardIterator, class T, class Compare>
-    constexpr ForwardIterator                         // constexpr in C++20
-    upper_bound(ForwardIterator first, ForwardIterator last, const T& value, Compare comp);
-
-template <class ForwardIterator, class T>
-    constexpr pair<ForwardIterator, ForwardIterator>  // constexpr in C++20
-    equal_range(ForwardIterator first, ForwardIterator last, const T& value);
-
-template <class ForwardIterator, class T, class Compare>
-    constexpr pair<ForwardIterator, ForwardIterator>  // constexpr in C++20
-    equal_range(ForwardIterator first, ForwardIterator last, const T& value, Compare comp);
-
-template <class ForwardIterator, class T>
-    constexpr bool                                    // constexpr in C++20
-    binary_search(ForwardIterator first, ForwardIterator last, const T& value);
-
-template <class ForwardIterator, class T, class Compare>
-    constexpr bool                                    // constexpr in C++20
-    binary_search(ForwardIterator first, ForwardIterator last, const T& value, Compare comp);
-
-template <class InputIterator1, class InputIterator2, class OutputIterator>
-    OutputIterator
-    merge(InputIterator1 first1, InputIterator1 last1,
-          InputIterator2 first2, InputIterator2 last2, OutputIterator result);
-
-template <class InputIterator1, class InputIterator2, class OutputIterator, class Compare>
-    OutputIterator
-    merge(InputIterator1 first1, InputIterator1 last1,
-          InputIterator2 first2, InputIterator2 last2, OutputIterator result, Compare comp);
-
-template <class BidirectionalIterator>
-    void
-    inplace_merge(BidirectionalIterator first, BidirectionalIterator middle, BidirectionalIterator last);
-
-template <class BidirectionalIterator, class Compare>
-    void
-    inplace_merge(BidirectionalIterator first, BidirectionalIterator middle, BidirectionalIterator last, Compare comp);
-
-template <class InputIterator1, class InputIterator2>
-    constexpr bool                                    // constexpr in C++20
-    includes(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, InputIterator2 last2);
-
-template <class InputIterator1, class InputIterator2, class Compare>
-    constexpr bool                                    // constexpr in C++20
-    includes(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, InputIterator2 last2, Compare comp);
-
-template <class InputIterator1, class InputIterator2, class OutputIterator>
-    OutputIterator
-    set_union(InputIterator1 first1, InputIterator1 last1,
-              InputIterator2 first2, InputIterator2 last2, OutputIterator result);
-
-template <class InputIterator1, class InputIterator2, class OutputIterator, class Compare>
-    OutputIterator
-    set_union(InputIterator1 first1, InputIterator1 last1,
-              InputIterator2 first2, InputIterator2 last2, OutputIterator result, Compare comp);
-
-template <class InputIterator1, class InputIterator2, class OutputIterator>
-    constexpr OutputIterator                         // constexpr in C++20
-    set_intersection(InputIterator1 first1, InputIterator1 last1,
-                     InputIterator2 first2, InputIterator2 last2, OutputIterator result);
-
-template <class InputIterator1, class InputIterator2, class OutputIterator, class Compare>
-    constexpr OutputIterator                         // constexpr in C++20
-    set_intersection(InputIterator1 first1, InputIterator1 last1,
-                     InputIterator2 first2, InputIterator2 last2, OutputIterator result, Compare comp);
-
-template <class InputIterator1, class InputIterator2, class OutputIterator>
-    OutputIterator
-    set_difference(InputIterator1 first1, InputIterator1 last1,
-                   InputIterator2 first2, InputIterator2 last2, OutputIterator result);
-
-template <class InputIterator1, class InputIterator2, class OutputIterator, class Compare>
-    OutputIterator
-    set_difference(InputIterator1 first1, InputIterator1 last1,
-                   InputIterator2 first2, InputIterator2 last2, OutputIterator result, Compare comp);
-
-template <class InputIterator1, class InputIterator2, class OutputIterator>
-    OutputIterator
-    set_symmetric_difference(InputIterator1 first1, InputIterator1 last1,
-                             InputIterator2 first2, InputIterator2 last2, OutputIterator result);
-
-template <class InputIterator1, class InputIterator2, class OutputIterator, class Compare>
-    OutputIterator
-    set_symmetric_difference(InputIterator1 first1, InputIterator1 last1,
-                             InputIterator2 first2, InputIterator2 last2, OutputIterator result, Compare comp);
-
-template <class RandomAccessIterator>
-    void
-    push_heap(RandomAccessIterator first, RandomAccessIterator last);
-
-template <class RandomAccessIterator, class Compare>
-    void
-    push_heap(RandomAccessIterator first, RandomAccessIterator last, Compare comp);
-
-template <class RandomAccessIterator>
-    void
-    pop_heap(RandomAccessIterator first, RandomAccessIterator last);
-
-template <class RandomAccessIterator, class Compare>
-    void
-    pop_heap(RandomAccessIterator first, RandomAccessIterator last, Compare comp);
-
-template <class RandomAccessIterator>
-    void
-    make_heap(RandomAccessIterator first, RandomAccessIterator last);
-
-template <class RandomAccessIterator, class Compare>
-    void
-    make_heap(RandomAccessIterator first, RandomAccessIterator last, Compare comp);
-
-template <class RandomAccessIterator>
-    void
-    sort_heap(RandomAccessIterator first, RandomAccessIterator last);
-
-template <class RandomAccessIterator, class Compare>
-    void
-    sort_heap(RandomAccessIterator first, RandomAccessIterator last, Compare comp);
-
-template <class RandomAccessIterator>
-    constexpr bool   // constexpr in C++20
-    is_heap(RandomAccessIterator first, RandomAccessiterator last);
-
-template <class RandomAccessIterator, class Compare>
-    constexpr bool   // constexpr in C++20
-    is_heap(RandomAccessIterator first, RandomAccessiterator last, Compare comp);
-
-template <class RandomAccessIterator>
-    constexpr RandomAccessIterator   // constexpr in C++20
-    is_heap_until(RandomAccessIterator first, RandomAccessiterator last);
-
-template <class RandomAccessIterator, class Compare>
-    constexpr RandomAccessIterator   // constexpr in C++20
-    is_heap_until(RandomAccessIterator first, RandomAccessiterator last, Compare comp);
-
-template <class ForwardIterator>
-    ForwardIterator
-    min_element(ForwardIterator first, ForwardIterator last);  // constexpr in C++14
-
-template <class ForwardIterator, class Compare>
-    ForwardIterator
-    min_element(ForwardIterator first, ForwardIterator last, Compare comp);  // constexpr in C++14
-
-template <class T>
-    const T&
-    min(const T& a, const T& b);  // constexpr in C++14
-
-template <class T, class Compare>
-    const T&
-    min(const T& a, const T& b, Compare comp);  // constexpr in C++14
-
-template<class T>
-    T
-    min(initializer_list<T> t);  // constexpr in C++14
-
-template<class T, class Compare>
-    T
-    min(initializer_list<T> t, Compare comp);  // constexpr in C++14
-
-template<class T>
-    constexpr const T& clamp( const T& v, const T& lo, const T& hi );               // C++17
-
-template<class T, class Compare>
-    constexpr const T& clamp( const T& v, const T& lo, const T& hi, Compare comp ); // C++17
-
-template <class ForwardIterator>
-    ForwardIterator
-    max_element(ForwardIterator first, ForwardIterator last);  // constexpr in C++14
-
-template <class ForwardIterator, class Compare>
-    ForwardIterator
-    max_element(ForwardIterator first, ForwardIterator last, Compare comp);  // constexpr in C++14
-
-template <class T>
-    const T&
-    max(const T& a, const T& b); // constexpr in C++14
-
-template <class T, class Compare>
-    const T&
-    max(const T& a, const T& b, Compare comp);  // constexpr in C++14
-
-template<class T>
-    T
-    max(initializer_list<T> t);  // constexpr in C++14
-
-template<class T, class Compare>
-    T
-    max(initializer_list<T> t, Compare comp);  // constexpr in C++14
-
-template<class ForwardIterator>
-    pair<ForwardIterator, ForwardIterator>
-    minmax_element(ForwardIterator first, ForwardIterator last);   // constexpr in C++14
-
-template<class ForwardIterator, class Compare>
-    pair<ForwardIterator, ForwardIterator>
-    minmax_element(ForwardIterator first, ForwardIterator last, Compare comp);   // constexpr in C++14
-
-template<class T>
-    pair<const T&, const T&>
-    minmax(const T& a, const T& b);  // constexpr in C++14
-
-template<class T, class Compare>
-    pair<const T&, const T&>
-    minmax(const T& a, const T& b, Compare comp);  // constexpr in C++14
-
-template<class T>
-    pair<T, T>
-    minmax(initializer_list<T> t);  // constexpr in C++14
-
-template<class T, class Compare>
-    pair<T, T>
-    minmax(initializer_list<T> t, Compare comp);  // constexpr in C++14
-
-template <class InputIterator1, class InputIterator2>
-    constexpr bool     // constexpr in C++20
-    lexicographical_compare(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, InputIterator2 last2);
-
-template <class InputIterator1, class InputIterator2, class Compare>
-    constexpr bool     // constexpr in C++20
-    lexicographical_compare(InputIterator1 first1, InputIterator1 last1,
-                            InputIterator2 first2, InputIterator2 last2, Compare comp);
-
-template <class BidirectionalIterator>
-    bool
-    next_permutation(BidirectionalIterator first, BidirectionalIterator last);
-
-template <class BidirectionalIterator, class Compare>
-    bool
-    next_permutation(BidirectionalIterator first, BidirectionalIterator last, Compare comp);
-
-template <class BidirectionalIterator>
-    bool
-    prev_permutation(BidirectionalIterator first, BidirectionalIterator last);
-
-template <class BidirectionalIterator, class Compare>
-    bool
-    prev_permutation(BidirectionalIterator first, BidirectionalIterator last, Compare comp);
-
-}  // std
-
-*/
-
-#include <__config>
-#include <initializer_list>
-#include <type_traits>
-#include <cstring>
-#include <utility> // needed to provide swap_ranges.
-#include <memory>
-#include <functional>
-#include <iterator>
-#include <cstddef>
-#include <bit>
-#include <version>
-
-#include <__debug>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_PUSH_MACROS
-#include <__undef_macros>
-
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-// I'd like to replace these with _VSTD::equal_to<void>, but can't because:
-//   * That only works with C++14 and later, and
-//   * We haven't included <functional> here.
-template <class _T1, class _T2 = _T1>
-struct __equal_to
-{
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 bool operator()(const _T1& __x, const _T1& __y) const {return __x == __y;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 bool operator()(const _T1& __x, const _T2& __y) const {return __x == __y;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 bool operator()(const _T2& __x, const _T1& __y) const {return __x == __y;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 bool operator()(const _T2& __x, const _T2& __y) const {return __x == __y;}
-};
-
-template <class _T1>
-struct __equal_to<_T1, _T1>
-{
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    bool operator()(const _T1& __x, const _T1& __y) const {return __x == __y;}
-};
-
-template <class _T1>
-struct __equal_to<const _T1, _T1>
-{
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    bool operator()(const _T1& __x, const _T1& __y) const {return __x == __y;}
-};
-
-template <class _T1>
-struct __equal_to<_T1, const _T1>
-{
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    bool operator()(const _T1& __x, const _T1& __y) const {return __x == __y;}
-};
-
-template <class _T1, class _T2 = _T1>
-struct __less
-{
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    bool operator()(const _T1& __x, const _T1& __y) const {return __x < __y;}
-
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    bool operator()(const _T1& __x, const _T2& __y) const {return __x < __y;}
-
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    bool operator()(const _T2& __x, const _T1& __y) const {return __x < __y;}
-
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    bool operator()(const _T2& __x, const _T2& __y) const {return __x < __y;}
-};
-
-template <class _T1>
-struct __less<_T1, _T1>
-{
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    bool operator()(const _T1& __x, const _T1& __y) const {return __x < __y;}
-};
-
-template <class _T1>
-struct __less<const _T1, _T1>
-{
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    bool operator()(const _T1& __x, const _T1& __y) const {return __x < __y;}
-};
-
-template <class _T1>
-struct __less<_T1, const _T1>
-{
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    bool operator()(const _T1& __x, const _T1& __y) const {return __x < __y;}
-};
-
-template <class _Predicate>
-class __invert // invert the sense of a comparison
-{
-private:
-    _Predicate __p_;
-public:
-    _LIBCPP_INLINE_VISIBILITY __invert() {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __invert(_Predicate __p) : __p_(__p) {}
-
-    template <class _T1>
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator()(const _T1& __x) {return !__p_(__x);}
-
-    template <class _T1, class _T2>
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator()(const _T1& __x, const _T2& __y) {return __p_(__y, __x);}
-};
-
-// Perform division by two quickly for positive integers (llvm.org/PR39129)
-
-template <typename _Integral>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-typename enable_if
-<
-    is_integral<_Integral>::value,
-    _Integral
->::type
-__half_positive(_Integral __value)
-{
-    return static_cast<_Integral>(static_cast<typename make_unsigned<_Integral>::type>(__value) / 2);
-}
-
-template <typename _Tp>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-typename enable_if
-<
-    !is_integral<_Tp>::value,
-    _Tp
->::type
-__half_positive(_Tp __value)
-{
-    return __value / 2;
-}
-
-#ifdef _LIBCPP_DEBUG
-
-template <class _Compare>
-struct __debug_less
-{
-    _Compare __comp_;
-    __debug_less(_Compare& __c) : __comp_(__c) {}
-
-    template <class _Tp, class _Up>
-    bool operator()(const _Tp& __x, const _Up& __y)
-    {
-        bool __r = __comp_(__x, __y);
-        if (__r)
-            __do_compare_assert(0, __y, __x);
-        return __r;
-    }
-
-    template <class _LHS, class _RHS>
-    inline _LIBCPP_INLINE_VISIBILITY
-    decltype((void)_VSTD::declval<_Compare&>()(
-        _VSTD::declval<_LHS const&>(), _VSTD::declval<_RHS const&>()))
-    __do_compare_assert(int, _LHS const& __l, _RHS const& __r) {
-        _LIBCPP_ASSERT(!__comp_(__l, __r),
-            "Comparator does not induce a strict weak ordering");
-    }
-
-    template <class _LHS, class _RHS>
-    inline _LIBCPP_INLINE_VISIBILITY
-    void __do_compare_assert(long, _LHS const&, _RHS const&) {}
-};
-
-#endif  // _LIBCPP_DEBUG
-
-// all_of
-
-template <class _InputIterator, class _Predicate>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-all_of(_InputIterator __first, _InputIterator __last, _Predicate __pred)
-{
-    for (; __first != __last; ++__first)
-        if (!__pred(*__first))
-            return false;
-    return true;
-}
-
-// any_of
-
-template <class _InputIterator, class _Predicate>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-any_of(_InputIterator __first, _InputIterator __last, _Predicate __pred)
-{
-    for (; __first != __last; ++__first)
-        if (__pred(*__first))
-            return true;
-    return false;
-}
-
-// none_of
-
-template <class _InputIterator, class _Predicate>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-none_of(_InputIterator __first, _InputIterator __last, _Predicate __pred)
-{
-    for (; __first != __last; ++__first)
-        if (__pred(*__first))
-            return false;
-    return true;
-}
-
-// for_each
-
-template <class _InputIterator, class _Function>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_Function
-for_each(_InputIterator __first, _InputIterator __last, _Function __f)
-{
-    for (; __first != __last; ++__first)
-        __f(*__first);
-    return __f;
-}
-
-#if _LIBCPP_STD_VER > 14
-// for_each_n
-
-template <class _InputIterator, class _Size, class _Function>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_InputIterator
-for_each_n(_InputIterator __first, _Size __orig_n, _Function __f)
-{
-    typedef decltype(__convert_to_integral(__orig_n)) _IntegralSize;
-    _IntegralSize __n = __orig_n;
-    while (__n > 0)
-    {
-         __f(*__first);
-         ++__first;
-         --__n;
-    }
-    return __first;
-}
-#endif
-
-// find
-
-template <class _InputIterator, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_InputIterator
-find(_InputIterator __first, _InputIterator __last, const _Tp& __value_)
-{
-    for (; __first != __last; ++__first)
-        if (*__first == __value_)
-            break;
-    return __first;
-}
-
-// find_if
-
-template <class _InputIterator, class _Predicate>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_InputIterator
-find_if(_InputIterator __first, _InputIterator __last, _Predicate __pred)
-{
-    for (; __first != __last; ++__first)
-        if (__pred(*__first))
-            break;
-    return __first;
-}
-
-// find_if_not
-
-template<class _InputIterator, class _Predicate>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_InputIterator
-find_if_not(_InputIterator __first, _InputIterator __last, _Predicate __pred)
-{
-    for (; __first != __last; ++__first)
-        if (!__pred(*__first))
-            break;
-    return __first;
-}
-
-// find_end
-
-template <class _BinaryPredicate, class _ForwardIterator1, class _ForwardIterator2>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator1
-__find_end(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
-           _ForwardIterator2 __first2, _ForwardIterator2 __last2, _BinaryPredicate __pred,
-           forward_iterator_tag, forward_iterator_tag)
-{
-    // modeled after search algorithm
-    _ForwardIterator1 __r = __last1;  // __last1 is the "default" answer
-    if (__first2 == __last2)
-        return __r;
-    while (true)
-    {
-        while (true)
-        {
-            if (__first1 == __last1)         // if source exhausted return last correct answer
-                return __r;                  //    (or __last1 if never found)
-            if (__pred(*__first1, *__first2))
-                break;
-            ++__first1;
-        }
-        // *__first1 matches *__first2, now match elements after here
-        _ForwardIterator1 __m1 = __first1;
-        _ForwardIterator2 __m2 = __first2;
-        while (true)
-        {
-            if (++__m2 == __last2)
-            {                         // Pattern exhaused, record answer and search for another one
-                __r = __first1;
-                ++__first1;
-                break;
-            }
-            if (++__m1 == __last1)     // Source exhausted, return last answer
-                return __r;
-            if (!__pred(*__m1, *__m2))  // mismatch, restart with a new __first
-            {
-                ++__first1;
-                break;
-            }  // else there is a match, check next elements
-        }
-    }
-}
-
-template <class _BinaryPredicate, class _BidirectionalIterator1, class _BidirectionalIterator2>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 _BidirectionalIterator1
-__find_end(_BidirectionalIterator1 __first1, _BidirectionalIterator1 __last1,
-           _BidirectionalIterator2 __first2, _BidirectionalIterator2 __last2, _BinaryPredicate __pred,
-           bidirectional_iterator_tag, bidirectional_iterator_tag)
-{
-    // modeled after search algorithm (in reverse)
-    if (__first2 == __last2)
-        return __last1;  // Everything matches an empty sequence
-    _BidirectionalIterator1 __l1 = __last1;
-    _BidirectionalIterator2 __l2 = __last2;
-    --__l2;
-    while (true)
-    {
-        // Find last element in sequence 1 that matchs *(__last2-1), with a mininum of loop checks
-        while (true)
-        {
-            if (__first1 == __l1)  // return __last1 if no element matches *__first2
-                return __last1;
-            if (__pred(*--__l1, *__l2))
-                break;
-        }
-        // *__l1 matches *__l2, now match elements before here
-        _BidirectionalIterator1 __m1 = __l1;
-        _BidirectionalIterator2 __m2 = __l2;
-        while (true)
-        {
-            if (__m2 == __first2)  // If pattern exhausted, __m1 is the answer (works for 1 element pattern)
-                return __m1;
-            if (__m1 == __first1)  // Otherwise if source exhaused, pattern not found
-                return __last1;
-            if (!__pred(*--__m1, *--__m2))  // if there is a mismatch, restart with a new __l1
-            {
-                break;
-            }  // else there is a match, check next elements
-        }
-    }
-}
-
-template <class _BinaryPredicate, class _RandomAccessIterator1, class _RandomAccessIterator2>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 _RandomAccessIterator1
-__find_end(_RandomAccessIterator1 __first1, _RandomAccessIterator1 __last1,
-           _RandomAccessIterator2 __first2, _RandomAccessIterator2 __last2, _BinaryPredicate __pred,
-           random_access_iterator_tag, random_access_iterator_tag)
-{
-    // Take advantage of knowing source and pattern lengths.  Stop short when source is smaller than pattern
-    typename iterator_traits<_RandomAccessIterator2>::difference_type __len2 = __last2 - __first2;
-    if (__len2 == 0)
-        return __last1;
-    typename iterator_traits<_RandomAccessIterator1>::difference_type __len1 = __last1 - __first1;
-    if (__len1 < __len2)
-        return __last1;
-    const _RandomAccessIterator1 __s = __first1 + (__len2 - 1);  // End of pattern match can't go before here
-    _RandomAccessIterator1 __l1 = __last1;
-    _RandomAccessIterator2 __l2 = __last2;
-    --__l2;
-    while (true)
-    {
-        while (true)
-        {
-            if (__s == __l1)
-                return __last1;
-            if (__pred(*--__l1, *__l2))
-                break;
-        }
-        _RandomAccessIterator1 __m1 = __l1;
-        _RandomAccessIterator2 __m2 = __l2;
-        while (true)
-        {
-            if (__m2 == __first2)
-                return __m1;
-                                 // no need to check range on __m1 because __s guarantees we have enough source
-            if (!__pred(*--__m1, *--__m2))
-            {
-                break;
-            }
-        }
-    }
-}
-
-template <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_ForwardIterator1
-find_end(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
-         _ForwardIterator2 __first2, _ForwardIterator2 __last2, _BinaryPredicate __pred)
-{
-    return _VSTD::__find_end<typename add_lvalue_reference<_BinaryPredicate>::type>
-                         (__first1, __last1, __first2, __last2, __pred,
-                          typename iterator_traits<_ForwardIterator1>::iterator_category(),
-                          typename iterator_traits<_ForwardIterator2>::iterator_category());
-}
-
-template <class _ForwardIterator1, class _ForwardIterator2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_ForwardIterator1
-find_end(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
-         _ForwardIterator2 __first2, _ForwardIterator2 __last2)
-{
-    typedef typename iterator_traits<_ForwardIterator1>::value_type __v1;
-    typedef typename iterator_traits<_ForwardIterator2>::value_type __v2;
-    return _VSTD::find_end(__first1, __last1, __first2, __last2, __equal_to<__v1, __v2>());
-}
-
-// find_first_of
-
-template <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 _ForwardIterator1
-__find_first_of_ce(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
-              _ForwardIterator2 __first2, _ForwardIterator2 __last2, _BinaryPredicate __pred)
-{
-    for (; __first1 != __last1; ++__first1)
-        for (_ForwardIterator2 __j = __first2; __j != __last2; ++__j)
-            if (__pred(*__first1, *__j))
-                return __first1;
-    return __last1;
-}
-
-
-template <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
-inline _LIBCPP_INLINE_VISIBILITY  _LIBCPP_CONSTEXPR_AFTER_CXX17
-_ForwardIterator1
-find_first_of(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
-              _ForwardIterator2 __first2, _ForwardIterator2 __last2, _BinaryPredicate __pred)
-{
-    return _VSTD::__find_first_of_ce(__first1, __last1, __first2, __last2, __pred);
-}
-
-template <class _ForwardIterator1, class _ForwardIterator2>
-inline _LIBCPP_INLINE_VISIBILITY  _LIBCPP_CONSTEXPR_AFTER_CXX17
-_ForwardIterator1
-find_first_of(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
-              _ForwardIterator2 __first2, _ForwardIterator2 __last2)
-{
-    typedef typename iterator_traits<_ForwardIterator1>::value_type __v1;
-    typedef typename iterator_traits<_ForwardIterator2>::value_type __v2;
-    return _VSTD::__find_first_of_ce(__first1, __last1, __first2, __last2, __equal_to<__v1, __v2>());
-}
-
-// adjacent_find
-
-template <class _ForwardIterator, class _BinaryPredicate>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_ForwardIterator
-adjacent_find(_ForwardIterator __first, _ForwardIterator __last, _BinaryPredicate __pred)
-{
-    if (__first != __last)
-    {
-        _ForwardIterator __i = __first;
-        while (++__i != __last)
-        {
-            if (__pred(*__first, *__i))
-                return __first;
-            __first = __i;
-        }
-    }
-    return __last;
-}
-
-template <class _ForwardIterator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_ForwardIterator
-adjacent_find(_ForwardIterator __first, _ForwardIterator __last)
-{
-    typedef typename iterator_traits<_ForwardIterator>::value_type __v;
-    return _VSTD::adjacent_find(__first, __last, __equal_to<__v>());
-}
-
-// count
-
-template <class _InputIterator, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-typename iterator_traits<_InputIterator>::difference_type
-count(_InputIterator __first, _InputIterator __last, const _Tp& __value_)
-{
-    typename iterator_traits<_InputIterator>::difference_type __r(0);
-    for (; __first != __last; ++__first)
-        if (*__first == __value_)
-            ++__r;
-    return __r;
-}
-
-// count_if
-
-template <class _InputIterator, class _Predicate>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-typename iterator_traits<_InputIterator>::difference_type
-count_if(_InputIterator __first, _InputIterator __last, _Predicate __pred)
-{
-    typename iterator_traits<_InputIterator>::difference_type __r(0);
-    for (; __first != __last; ++__first)
-        if (__pred(*__first))
-            ++__r;
-    return __r;
-}
-
-// mismatch
-
-template <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-pair<_InputIterator1, _InputIterator2>
-mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
-         _InputIterator2 __first2, _BinaryPredicate __pred)
-{
-    for (; __first1 != __last1; ++__first1, (void) ++__first2)
-        if (!__pred(*__first1, *__first2))
-            break;
-    return pair<_InputIterator1, _InputIterator2>(__first1, __first2);
-}
-
-template <class _InputIterator1, class _InputIterator2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-pair<_InputIterator1, _InputIterator2>
-mismatch(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2)
-{
-    typedef typename iterator_traits<_InputIterator1>::value_type __v1;
-    typedef typename iterator_traits<_InputIterator2>::value_type __v2;
-    return _VSTD::mismatch(__first1, __last1, __first2, __equal_to<__v1, __v2>());
-}
-
-#if _LIBCPP_STD_VER > 11
-template <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-pair<_InputIterator1, _InputIterator2>
-mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
-         _InputIterator2 __first2, _InputIterator2 __last2,
-         _BinaryPredicate __pred)
-{
-    for (; __first1 != __last1 && __first2 != __last2; ++__first1, (void) ++__first2)
-        if (!__pred(*__first1, *__first2))
-            break;
-    return pair<_InputIterator1, _InputIterator2>(__first1, __first2);
-}
-
-template <class _InputIterator1, class _InputIterator2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-pair<_InputIterator1, _InputIterator2>
-mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
-         _InputIterator2 __first2, _InputIterator2 __last2)
-{
-    typedef typename iterator_traits<_InputIterator1>::value_type __v1;
-    typedef typename iterator_traits<_InputIterator2>::value_type __v2;
-    return _VSTD::mismatch(__first1, __last1, __first2, __last2, __equal_to<__v1, __v2>());
-}
-#endif
-
-// equal
-
-template <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-equal(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _BinaryPredicate __pred)
-{
-    for (; __first1 != __last1; ++__first1, (void) ++__first2)
-        if (!__pred(*__first1, *__first2))
-            return false;
-    return true;
-}
-
-template <class _InputIterator1, class _InputIterator2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-equal(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2)
-{
-    typedef typename iterator_traits<_InputIterator1>::value_type __v1;
-    typedef typename iterator_traits<_InputIterator2>::value_type __v2;
-    return _VSTD::equal(__first1, __last1, __first2, __equal_to<__v1, __v2>());
-}
-
-#if _LIBCPP_STD_VER > 11
-template <class _BinaryPredicate, class _InputIterator1, class _InputIterator2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-__equal(_InputIterator1 __first1, _InputIterator1 __last1,
-        _InputIterator2 __first2, _InputIterator2 __last2, _BinaryPredicate __pred,
-        input_iterator_tag, input_iterator_tag )
-{
-    for (; __first1 != __last1 && __first2 != __last2; ++__first1, (void) ++__first2)
-        if (!__pred(*__first1, *__first2))
-            return false;
-    return __first1 == __last1 && __first2 == __last2;
-}
-
-template <class _BinaryPredicate, class _RandomAccessIterator1, class _RandomAccessIterator2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-__equal(_RandomAccessIterator1 __first1, _RandomAccessIterator1 __last1,
-        _RandomAccessIterator2 __first2, _RandomAccessIterator2 __last2, _BinaryPredicate __pred,
-      random_access_iterator_tag, random_access_iterator_tag )
-{
-    if ( _VSTD::distance(__first1, __last1) != _VSTD::distance(__first2, __last2))
-        return false;
-    return _VSTD::equal<_RandomAccessIterator1, _RandomAccessIterator2,
-                        typename add_lvalue_reference<_BinaryPredicate>::type>
-                       (__first1, __last1, __first2, __pred );
-}
-
-template <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-equal(_InputIterator1 __first1, _InputIterator1 __last1,
-      _InputIterator2 __first2, _InputIterator2 __last2, _BinaryPredicate __pred )
-{
-    return _VSTD::__equal<typename add_lvalue_reference<_BinaryPredicate>::type>
-       (__first1, __last1, __first2, __last2, __pred,
-        typename iterator_traits<_InputIterator1>::iterator_category(),
-        typename iterator_traits<_InputIterator2>::iterator_category());
-}
-
-template <class _InputIterator1, class _InputIterator2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-equal(_InputIterator1 __first1, _InputIterator1 __last1,
-      _InputIterator2 __first2, _InputIterator2 __last2)
-{
-    typedef typename iterator_traits<_InputIterator1>::value_type __v1;
-    typedef typename iterator_traits<_InputIterator2>::value_type __v2;
-    return _VSTD::__equal(__first1, __last1, __first2, __last2, __equal_to<__v1, __v2>(),
-        typename iterator_traits<_InputIterator1>::iterator_category(),
-        typename iterator_traits<_InputIterator2>::iterator_category());
-}
-#endif
-
-// is_permutation
-
-template<class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
-is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
-               _ForwardIterator2 __first2, _BinaryPredicate __pred)
-{
-//  shorten sequences as much as possible by lopping of any equal prefix
-    for (; __first1 != __last1; ++__first1, (void) ++__first2)
-        if (!__pred(*__first1, *__first2))
-            break;
-    if (__first1 == __last1)
-        return true;
-
-//  __first1 != __last1 && *__first1 != *__first2
-    typedef typename iterator_traits<_ForwardIterator1>::difference_type _D1;
-    _D1 __l1 = _VSTD::distance(__first1, __last1);
-    if (__l1 == _D1(1))
-        return false;
-    _ForwardIterator2 __last2 = _VSTD::next(__first2, __l1);
-    // For each element in [f1, l1) see if there are the same number of
-    //    equal elements in [f2, l2)
-    for (_ForwardIterator1 __i = __first1; __i != __last1; ++__i)
-    {
-    //  Have we already counted the number of *__i in [f1, l1)?
-        _ForwardIterator1 __match = __first1;
-        for (; __match != __i; ++__match)
-            if (__pred(*__match, *__i))
-                break;
-        if (__match == __i) {
-            // Count number of *__i in [f2, l2)
-            _D1 __c2 = 0;
-            for (_ForwardIterator2 __j = __first2; __j != __last2; ++__j)
-                if (__pred(*__i, *__j))
-                    ++__c2;
-            if (__c2 == 0)
-                return false;
-            // Count number of *__i in [__i, l1) (we can start with 1)
-            _D1 __c1 = 1;
-            for (_ForwardIterator1 __j = _VSTD::next(__i); __j != __last1; ++__j)
-                if (__pred(*__i, *__j))
-                    ++__c1;
-            if (__c1 != __c2)
-                return false;
-        }
-    }
-    return true;
-}
-
-template<class _ForwardIterator1, class _ForwardIterator2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
-               _ForwardIterator2 __first2)
-{
-    typedef typename iterator_traits<_ForwardIterator1>::value_type __v1;
-    typedef typename iterator_traits<_ForwardIterator2>::value_type __v2;
-    return _VSTD::is_permutation(__first1, __last1, __first2, __equal_to<__v1, __v2>());
-}
-
-#if _LIBCPP_STD_VER > 11
-template<class _BinaryPredicate, class _ForwardIterator1, class _ForwardIterator2>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
-__is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
-                 _ForwardIterator2 __first2, _ForwardIterator2 __last2,
-                 _BinaryPredicate __pred,
-                 forward_iterator_tag, forward_iterator_tag )
-{
-//  shorten sequences as much as possible by lopping of any equal prefix
-    for (; __first1 != __last1 && __first2 != __last2; ++__first1, (void) ++__first2)
-        if (!__pred(*__first1, *__first2))
-            break;
-    if (__first1 == __last1)
-        return __first2 == __last2;
-    else if (__first2 == __last2)
-        return false;
-
-    typedef typename iterator_traits<_ForwardIterator1>::difference_type _D1;
-    _D1 __l1 = _VSTD::distance(__first1, __last1);
-
-    typedef typename iterator_traits<_ForwardIterator2>::difference_type _D2;
-    _D2 __l2 = _VSTD::distance(__first2, __last2);
-    if (__l1 != __l2)
-        return false;
-
-    // For each element in [f1, l1) see if there are the same number of
-    //    equal elements in [f2, l2)
-    for (_ForwardIterator1 __i = __first1; __i != __last1; ++__i)
-    {
-    //  Have we already counted the number of *__i in [f1, l1)?
-        _ForwardIterator1 __match = __first1;
-        for (; __match != __i; ++__match)
-            if (__pred(*__match, *__i))
-                break;
-        if (__match == __i) {
-            // Count number of *__i in [f2, l2)
-            _D1 __c2 = 0;
-            for (_ForwardIterator2 __j = __first2; __j != __last2; ++__j)
-                if (__pred(*__i, *__j))
-                    ++__c2;
-            if (__c2 == 0)
-                return false;
-            // Count number of *__i in [__i, l1) (we can start with 1)
-            _D1 __c1 = 1;
-            for (_ForwardIterator1 __j = _VSTD::next(__i); __j != __last1; ++__j)
-                if (__pred(*__i, *__j))
-                    ++__c1;
-            if (__c1 != __c2)
-                return false;
-        }
-    }
-    return true;
-}
-
-template<class _BinaryPredicate, class _RandomAccessIterator1, class _RandomAccessIterator2>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
-__is_permutation(_RandomAccessIterator1 __first1, _RandomAccessIterator2 __last1,
-               _RandomAccessIterator1 __first2, _RandomAccessIterator2 __last2,
-               _BinaryPredicate __pred,
-               random_access_iterator_tag, random_access_iterator_tag )
-{
-    if ( _VSTD::distance(__first1, __last1) != _VSTD::distance(__first2, __last2))
-        return false;
-    return _VSTD::is_permutation<_RandomAccessIterator1, _RandomAccessIterator2,
-                                 typename add_lvalue_reference<_BinaryPredicate>::type>
-                                (__first1, __last1, __first2, __pred );
-}
-
-template<class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
-               _ForwardIterator2 __first2, _ForwardIterator2 __last2,
-               _BinaryPredicate __pred )
-{
-    return _VSTD::__is_permutation<typename add_lvalue_reference<_BinaryPredicate>::type>
-       (__first1, __last1, __first2, __last2, __pred,
-        typename iterator_traits<_ForwardIterator1>::iterator_category(),
-        typename iterator_traits<_ForwardIterator2>::iterator_category());
-}
-
-template<class _ForwardIterator1, class _ForwardIterator2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
-               _ForwardIterator2 __first2, _ForwardIterator2 __last2)
-{
-    typedef typename iterator_traits<_ForwardIterator1>::value_type __v1;
-    typedef typename iterator_traits<_ForwardIterator2>::value_type __v2;
-    return _VSTD::__is_permutation(__first1, __last1, __first2, __last2,
-        __equal_to<__v1, __v2>(),
-        typename iterator_traits<_ForwardIterator1>::iterator_category(),
-        typename iterator_traits<_ForwardIterator2>::iterator_category());
-}
-#endif
-
-// search
-// __search is in <functional>
-
-template <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_ForwardIterator1
-search(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
-       _ForwardIterator2 __first2, _ForwardIterator2 __last2, _BinaryPredicate __pred)
-{
-    return _VSTD::__search<typename add_lvalue_reference<_BinaryPredicate>::type>
-                         (__first1, __last1, __first2, __last2, __pred,
-                          typename iterator_traits<_ForwardIterator1>::iterator_category(),
-                          typename iterator_traits<_ForwardIterator2>::iterator_category())
-            .first;
-}
-
-template <class _ForwardIterator1, class _ForwardIterator2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_ForwardIterator1
-search(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
-       _ForwardIterator2 __first2, _ForwardIterator2 __last2)
-{
-    typedef typename iterator_traits<_ForwardIterator1>::value_type __v1;
-    typedef typename iterator_traits<_ForwardIterator2>::value_type __v2;
-    return _VSTD::search(__first1, __last1, __first2, __last2, __equal_to<__v1, __v2>());
-}
-
-
-#if _LIBCPP_STD_VER > 14
-template <class _ForwardIterator, class _Searcher>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_ForwardIterator search(_ForwardIterator __f, _ForwardIterator __l, const _Searcher &__s)
-{ return __s(__f, __l).first; }
-#endif
-
-// search_n
-
-template <class _BinaryPredicate, class _ForwardIterator, class _Size, class _Tp>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
-__search_n(_ForwardIterator __first, _ForwardIterator __last,
-           _Size __count, const _Tp& __value_, _BinaryPredicate __pred, forward_iterator_tag)
-{
-    if (__count <= 0)
-        return __first;
-    while (true)
-    {
-        // Find first element in sequence that matchs __value_, with a mininum of loop checks
-        while (true)
-        {
-            if (__first == __last)  // return __last if no element matches __value_
-                return __last;
-            if (__pred(*__first, __value_))
-                break;
-            ++__first;
-        }
-        // *__first matches __value_, now match elements after here
-        _ForwardIterator __m = __first;
-        _Size __c(0);
-        while (true)
-        {
-            if (++__c == __count)  // If pattern exhausted, __first is the answer (works for 1 element pattern)
-                return __first;
-            if (++__m == __last)  // Otherwise if source exhaused, pattern not found
-                return __last;
-            if (!__pred(*__m, __value_))  // if there is a mismatch, restart with a new __first
-            {
-                __first = __m;
-                ++__first;
-                break;
-            }  // else there is a match, check next elements
-        }
-    }
-}
-
-template <class _BinaryPredicate, class _RandomAccessIterator, class _Size, class _Tp>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 _RandomAccessIterator
-__search_n(_RandomAccessIterator __first, _RandomAccessIterator __last,
-           _Size __count, const _Tp& __value_, _BinaryPredicate __pred, random_access_iterator_tag)
-{
-    if (__count <= 0)
-        return __first;
-    _Size __len = static_cast<_Size>(__last - __first);
-    if (__len < __count)
-        return __last;
-    const _RandomAccessIterator __s = __last - (__count - 1);  // Start of pattern match can't go beyond here
-    while (true)
-    {
-        // Find first element in sequence that matchs __value_, with a mininum of loop checks
-        while (true)
-        {
-            if (__first >= __s)  // return __last if no element matches __value_
-                return __last;
-            if (__pred(*__first, __value_))
-                break;
-            ++__first;
-        }
-        // *__first matches __value_, now match elements after here
-        _RandomAccessIterator __m = __first;
-        _Size __c(0);
-        while (true)
-        {
-            if (++__c == __count)  // If pattern exhausted, __first is the answer (works for 1 element pattern)
-                return __first;
-             ++__m;          // no need to check range on __m because __s guarantees we have enough source
-            if (!__pred(*__m, __value_))  // if there is a mismatch, restart with a new __first
-            {
-                __first = __m;
-                ++__first;
-                break;
-            }  // else there is a match, check next elements
-        }
-    }
-}
-
-template <class _ForwardIterator, class _Size, class _Tp, class _BinaryPredicate>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_ForwardIterator
-search_n(_ForwardIterator __first, _ForwardIterator __last,
-         _Size __count, const _Tp& __value_, _BinaryPredicate __pred)
-{
-    return _VSTD::__search_n<typename add_lvalue_reference<_BinaryPredicate>::type>
-           (__first, __last, __convert_to_integral(__count), __value_, __pred,
-           typename iterator_traits<_ForwardIterator>::iterator_category());
-}
-
-template <class _ForwardIterator, class _Size, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_ForwardIterator
-search_n(_ForwardIterator __first, _ForwardIterator __last, _Size __count, const _Tp& __value_)
-{
-    typedef typename iterator_traits<_ForwardIterator>::value_type __v;
-    return _VSTD::search_n(__first, __last, __convert_to_integral(__count),
-                           __value_, __equal_to<__v, _Tp>());
-}
-
-// copy
-template <class _Iter>
-inline _LIBCPP_INLINE_VISIBILITY
-_Iter
-__unwrap_iter(_Iter __i)
-{
-    return __i;
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    is_trivially_copy_assignable<_Tp>::value,
-    _Tp*
->::type
-__unwrap_iter(move_iterator<_Tp*> __i)
-{
-    return __i.base();
-}
-
-#if _LIBCPP_DEBUG_LEVEL < 2
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
-typename enable_if
-<
-    is_trivially_copy_assignable<_Tp>::value,
-    _Tp*
->::type
-__unwrap_iter(__wrap_iter<_Tp*> __i)
-{
-    return __i.base();
-}
-
-#else
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
-typename enable_if
-<
-    is_trivially_copy_assignable<_Tp>::value,
-    __wrap_iter<_Tp*>
->::type
-__unwrap_iter(__wrap_iter<_Tp*> __i)
-{
-    return __i;
-}
-
-#endif  // _LIBCPP_DEBUG_LEVEL < 2
-
-template <class _InputIterator, class _OutputIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-_OutputIterator
-__copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
-{
-    for (; __first != __last; ++__first, (void) ++__result)
-        *__result = *__first;
-    return __result;
-}
-
-template <class _Tp, class _Up>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    is_same<typename remove_const<_Tp>::type, _Up>::value &&
-    is_trivially_copy_assignable<_Up>::value,
-    _Up*
->::type
-__copy(_Tp* __first, _Tp* __last, _Up* __result)
-{
-    const size_t __n = static_cast<size_t>(__last - __first);
-    if (__n > 0)
-        _VSTD::memmove(__result, __first, __n * sizeof(_Up));
-    return __result + __n;
-}
-
-template <class _InputIterator, class _OutputIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-_OutputIterator
-copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
-{
-    return _VSTD::__copy(__unwrap_iter(__first), __unwrap_iter(__last), __unwrap_iter(__result));
-}
-
-// copy_backward
-
-template <class _BidirectionalIterator, class _OutputIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-_OutputIterator
-__copy_backward(_BidirectionalIterator __first, _BidirectionalIterator __last, _OutputIterator __result)
-{
-    while (__first != __last)
-        *--__result = *--__last;
-    return __result;
-}
-
-template <class _Tp, class _Up>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    is_same<typename remove_const<_Tp>::type, _Up>::value &&
-    is_trivially_copy_assignable<_Up>::value,
-    _Up*
->::type
-__copy_backward(_Tp* __first, _Tp* __last, _Up* __result)
-{
-    const size_t __n = static_cast<size_t>(__last - __first);
-    if (__n > 0)
-    {
-        __result -= __n;
-        _VSTD::memmove(__result, __first, __n * sizeof(_Up));
-    }
-    return __result;
-}
-
-template <class _BidirectionalIterator1, class _BidirectionalIterator2>
-inline _LIBCPP_INLINE_VISIBILITY
-_BidirectionalIterator2
-copy_backward(_BidirectionalIterator1 __first, _BidirectionalIterator1 __last,
-              _BidirectionalIterator2 __result)
-{
-    return _VSTD::__copy_backward(__unwrap_iter(__first),
-                                  __unwrap_iter(__last),
-                                  __unwrap_iter(__result));
-}
-
-// copy_if
-
-template<class _InputIterator, class _OutputIterator, class _Predicate>
-inline _LIBCPP_INLINE_VISIBILITY
-_OutputIterator
-copy_if(_InputIterator __first, _InputIterator __last,
-        _OutputIterator __result, _Predicate __pred)
-{
-    for (; __first != __last; ++__first)
-    {
-        if (__pred(*__first))
-        {
-            *__result = *__first;
-            ++__result;
-        }
-    }
-    return __result;
-}
-
-// copy_n
-
-template<class _InputIterator, class _Size, class _OutputIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_input_iterator<_InputIterator>::value &&
-   !__is_random_access_iterator<_InputIterator>::value,
-    _OutputIterator
->::type
-copy_n(_InputIterator __first, _Size __orig_n, _OutputIterator __result)
-{
-    typedef decltype(__convert_to_integral(__orig_n)) _IntegralSize;
-    _IntegralSize __n = __orig_n;
-    if (__n > 0)
-    {
-        *__result = *__first;
-        ++__result;
-        for (--__n; __n > 0; --__n)
-        {
-            ++__first;
-            *__result = *__first;
-            ++__result;
-        }
-    }
-    return __result;
-}
-
-template<class _InputIterator, class _Size, class _OutputIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_random_access_iterator<_InputIterator>::value,
-    _OutputIterator
->::type
-copy_n(_InputIterator __first, _Size __orig_n, _OutputIterator __result)
-{
-    typedef decltype(__convert_to_integral(__orig_n)) _IntegralSize;
-    _IntegralSize __n = __orig_n;
-    return _VSTD::copy(__first, __first + __n, __result);
-}
-
-// move
-
-template <class _InputIterator, class _OutputIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-_OutputIterator
-__move(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
-{
-    for (; __first != __last; ++__first, (void) ++__result)
-        *__result = _VSTD::move(*__first);
-    return __result;
-}
-
-template <class _Tp, class _Up>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    is_same<typename remove_const<_Tp>::type, _Up>::value &&
-    is_trivially_copy_assignable<_Up>::value,
-    _Up*
->::type
-__move(_Tp* __first, _Tp* __last, _Up* __result)
-{
-    const size_t __n = static_cast<size_t>(__last - __first);
-    if (__n > 0)
-        _VSTD::memmove(__result, __first, __n * sizeof(_Up));
-    return __result + __n;
-}
-
-template <class _InputIterator, class _OutputIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-_OutputIterator
-move(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
-{
-    return _VSTD::__move(__unwrap_iter(__first), __unwrap_iter(__last), __unwrap_iter(__result));
-}
-
-// move_backward
-
-template <class _InputIterator, class _OutputIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-_OutputIterator
-__move_backward(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
-{
-    while (__first != __last)
-        *--__result = _VSTD::move(*--__last);
-    return __result;
-}
-
-template <class _Tp, class _Up>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    is_same<typename remove_const<_Tp>::type, _Up>::value &&
-    is_trivially_copy_assignable<_Up>::value,
-    _Up*
->::type
-__move_backward(_Tp* __first, _Tp* __last, _Up* __result)
-{
-    const size_t __n = static_cast<size_t>(__last - __first);
-    if (__n > 0)
-    {
-        __result -= __n;
-        _VSTD::memmove(__result, __first, __n * sizeof(_Up));
-    }
-    return __result;
-}
-
-template <class _BidirectionalIterator1, class _BidirectionalIterator2>
-inline _LIBCPP_INLINE_VISIBILITY
-_BidirectionalIterator2
-move_backward(_BidirectionalIterator1 __first, _BidirectionalIterator1 __last,
-              _BidirectionalIterator2 __result)
-{
-    return _VSTD::__move_backward(__unwrap_iter(__first), __unwrap_iter(__last), __unwrap_iter(__result));
-}
-
-// iter_swap
-
-// moved to <type_traits> for better swap / noexcept support
-
-// transform
-
-template <class _InputIterator, class _OutputIterator, class _UnaryOperation>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_OutputIterator
-transform(_InputIterator __first, _InputIterator __last, _OutputIterator __result, _UnaryOperation __op)
-{
-    for (; __first != __last; ++__first, (void) ++__result)
-        *__result = __op(*__first);
-    return __result;
-}
-
-template <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _BinaryOperation>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_OutputIterator
-transform(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2,
-          _OutputIterator __result, _BinaryOperation __binary_op)
-{
-    for (; __first1 != __last1; ++__first1, (void) ++__first2, ++__result)
-        *__result = __binary_op(*__first1, *__first2);
-    return __result;
-}
-
-// replace
-
-template <class _ForwardIterator, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-void
-replace(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __old_value, const _Tp& __new_value)
-{
-    for (; __first != __last; ++__first)
-        if (*__first == __old_value)
-            *__first = __new_value;
-}
-
-// replace_if
-
-template <class _ForwardIterator, class _Predicate, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-void
-replace_if(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred, const _Tp& __new_value)
-{
-    for (; __first != __last; ++__first)
-        if (__pred(*__first))
-            *__first = __new_value;
-}
-
-// replace_copy
-
-template <class _InputIterator, class _OutputIterator, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_OutputIterator
-replace_copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result,
-             const _Tp& __old_value, const _Tp& __new_value)
-{
-    for (; __first != __last; ++__first, (void) ++__result)
-        if (*__first == __old_value)
-            *__result = __new_value;
-        else
-            *__result = *__first;
-    return __result;
-}
-
-// replace_copy_if
-
-template <class _InputIterator, class _OutputIterator, class _Predicate, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_OutputIterator
-replace_copy_if(_InputIterator __first, _InputIterator __last, _OutputIterator __result,
-                _Predicate __pred, const _Tp& __new_value)
-{
-    for (; __first != __last; ++__first, (void) ++__result)
-        if (__pred(*__first))
-            *__result = __new_value;
-        else
-            *__result = *__first;
-    return __result;
-}
-
-// fill_n
-
-template <class _OutputIterator, class _Size, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_OutputIterator
-__fill_n(_OutputIterator __first, _Size __n, const _Tp& __value_)
-{
-    for (; __n > 0; ++__first, (void) --__n)
-        *__first = __value_;
-    return __first;
-}
-
-template <class _OutputIterator, class _Size, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_OutputIterator
-fill_n(_OutputIterator __first, _Size __n, const _Tp& __value_)
-{
-   return _VSTD::__fill_n(__first, __convert_to_integral(__n), __value_);
-}
-
-// fill
-
-template <class _ForwardIterator, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-void
-__fill(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, forward_iterator_tag)
-{
-    for (; __first != __last; ++__first)
-        *__first = __value_;
-}
-
-template <class _RandomAccessIterator, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-void
-__fill(_RandomAccessIterator __first, _RandomAccessIterator __last, const _Tp& __value_, random_access_iterator_tag)
-{
-    _VSTD::fill_n(__first, __last - __first, __value_);
-}
-
-template <class _ForwardIterator, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-void
-fill(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_)
-{
-    _VSTD::__fill(__first, __last, __value_, typename iterator_traits<_ForwardIterator>::iterator_category());
-}
-
-// generate
-
-template <class _ForwardIterator, class _Generator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-void
-generate(_ForwardIterator __first, _ForwardIterator __last, _Generator __gen)
-{
-    for (; __first != __last; ++__first)
-        *__first = __gen();
-}
-
-// generate_n
-
-template <class _OutputIterator, class _Size, class _Generator>
-inline _LIBCPP_INLINE_VISIBILITY  _LIBCPP_CONSTEXPR_AFTER_CXX17
-_OutputIterator
-generate_n(_OutputIterator __first, _Size __orig_n, _Generator __gen)
-{
-    typedef decltype(__convert_to_integral(__orig_n)) _IntegralSize;
-    _IntegralSize __n = __orig_n;
-    for (; __n > 0; ++__first, (void) --__n)
-        *__first = __gen();
-    return __first;
-}
-
-// remove
-
-template <class _ForwardIterator, class _Tp>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
-remove(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_)
-{
-    __first = _VSTD::find(__first, __last, __value_);
-    if (__first != __last)
-    {
-        _ForwardIterator __i = __first;
-        while (++__i != __last)
-        {
-            if (!(*__i == __value_))
-            {
-                *__first = _VSTD::move(*__i);
-                ++__first;
-            }
-        }
-    }
-    return __first;
-}
-
-// remove_if
-
-template <class _ForwardIterator, class _Predicate>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
-remove_if(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred)
-{
-    __first = _VSTD::find_if<_ForwardIterator, typename add_lvalue_reference<_Predicate>::type>
-                           (__first, __last, __pred);
-    if (__first != __last)
-    {
-        _ForwardIterator __i = __first;
-        while (++__i != __last)
-        {
-            if (!__pred(*__i))
-            {
-                *__first = _VSTD::move(*__i);
-                ++__first;
-            }
-        }
-    }
-    return __first;
-}
-
-// remove_copy
-
-template <class _InputIterator, class _OutputIterator, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_OutputIterator
-remove_copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result, const _Tp& __value_)
-{
-    for (; __first != __last; ++__first)
-    {
-        if (!(*__first == __value_))
-        {
-            *__result = *__first;
-            ++__result;
-        }
-    }
-    return __result;
-}
-
-// remove_copy_if
-
-template <class _InputIterator, class _OutputIterator, class _Predicate>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_OutputIterator
-remove_copy_if(_InputIterator __first, _InputIterator __last, _OutputIterator __result, _Predicate __pred)
-{
-    for (; __first != __last; ++__first)
-    {
-        if (!__pred(*__first))
-        {
-            *__result = *__first;
-            ++__result;
-        }
-    }
-    return __result;
-}
-
-// unique
-
-template <class _ForwardIterator, class _BinaryPredicate>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
-unique(_ForwardIterator __first, _ForwardIterator __last, _BinaryPredicate __pred)
-{
-    __first = _VSTD::adjacent_find<_ForwardIterator, typename add_lvalue_reference<_BinaryPredicate>::type>
-                                 (__first, __last, __pred);
-    if (__first != __last)
-    {
-        // ...  a  a  ?  ...
-        //      f     i
-        _ForwardIterator __i = __first;
-        for (++__i; ++__i != __last;)
-            if (!__pred(*__first, *__i))
-                *++__first = _VSTD::move(*__i);
-        ++__first;
-    }
-    return __first;
-}
-
-template <class _ForwardIterator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_ForwardIterator
-unique(_ForwardIterator __first, _ForwardIterator __last)
-{
-    typedef typename iterator_traits<_ForwardIterator>::value_type __v;
-    return _VSTD::unique(__first, __last, __equal_to<__v>());
-}
-
-// unique_copy
-
-template <class _BinaryPredicate, class _InputIterator, class _OutputIterator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 _OutputIterator
-__unique_copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result, _BinaryPredicate __pred,
-              input_iterator_tag, output_iterator_tag)
-{
-    if (__first != __last)
-    {
-        typename iterator_traits<_InputIterator>::value_type __t(*__first);
-        *__result = __t;
-        ++__result;
-        while (++__first != __last)
-        {
-            if (!__pred(__t, *__first))
-            {
-                __t = *__first;
-                *__result = __t;
-                ++__result;
-            }
-        }
-    }
-    return __result;
-}
-
-template <class _BinaryPredicate, class _ForwardIterator, class _OutputIterator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 _OutputIterator
-__unique_copy(_ForwardIterator __first, _ForwardIterator __last, _OutputIterator __result, _BinaryPredicate __pred,
-              forward_iterator_tag, output_iterator_tag)
-{
-    if (__first != __last)
-    {
-        _ForwardIterator __i = __first;
-        *__result = *__i;
-        ++__result;
-        while (++__first != __last)
-        {
-            if (!__pred(*__i, *__first))
-            {
-                *__result = *__first;
-                ++__result;
-                __i = __first;
-            }
-        }
-    }
-    return __result;
-}
-
-template <class _BinaryPredicate, class _InputIterator, class _ForwardIterator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
-__unique_copy(_InputIterator __first, _InputIterator __last, _ForwardIterator __result, _BinaryPredicate __pred,
-              input_iterator_tag, forward_iterator_tag)
-{
-    if (__first != __last)
-    {
-        *__result = *__first;
-        while (++__first != __last)
-            if (!__pred(*__result, *__first))
-                *++__result = *__first;
-        ++__result;
-    }
-    return __result;
-}
-
-template <class _InputIterator, class _OutputIterator, class _BinaryPredicate>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_OutputIterator
-unique_copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result, _BinaryPredicate __pred)
-{
-    return _VSTD::__unique_copy<typename add_lvalue_reference<_BinaryPredicate>::type>
-                              (__first, __last, __result, __pred,
-                               typename iterator_traits<_InputIterator>::iterator_category(),
-                               typename iterator_traits<_OutputIterator>::iterator_category());
-}
-
-template <class _InputIterator, class _OutputIterator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_OutputIterator
-unique_copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
-{
-    typedef typename iterator_traits<_InputIterator>::value_type __v;
-    return _VSTD::unique_copy(__first, __last, __result, __equal_to<__v>());
-}
-
-// reverse
-
-template <class _BidirectionalIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-__reverse(_BidirectionalIterator __first, _BidirectionalIterator __last, bidirectional_iterator_tag)
-{
-    while (__first != __last)
-    {
-        if (__first == --__last)
-            break;
-        _VSTD::iter_swap(__first, __last);
-        ++__first;
-    }
-}
-
-template <class _RandomAccessIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-__reverse(_RandomAccessIterator __first, _RandomAccessIterator __last, random_access_iterator_tag)
-{
-    if (__first != __last)
-        for (; __first < --__last; ++__first)
-            _VSTD::iter_swap(__first, __last);
-}
-
-template <class _BidirectionalIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-reverse(_BidirectionalIterator __first, _BidirectionalIterator __last)
-{
-    _VSTD::__reverse(__first, __last, typename iterator_traits<_BidirectionalIterator>::iterator_category());
-}
-
-// reverse_copy
-
-template <class _BidirectionalIterator, class _OutputIterator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_OutputIterator
-reverse_copy(_BidirectionalIterator __first, _BidirectionalIterator __last, _OutputIterator __result)
-{
-    for (; __first != __last; ++__result)
-        *__result = *--__last;
-    return __result;
-}
-
-// rotate
-
-template <class _ForwardIterator>
-_ForwardIterator
-__rotate_left(_ForwardIterator __first, _ForwardIterator __last)
-{
-    typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
-    value_type __tmp = _VSTD::move(*__first);
-    _ForwardIterator __lm1 = _VSTD::move(_VSTD::next(__first), __last, __first);
-    *__lm1 = _VSTD::move(__tmp);
-    return __lm1;
-}
-
-template <class _BidirectionalIterator>
-_BidirectionalIterator
-__rotate_right(_BidirectionalIterator __first, _BidirectionalIterator __last)
-{
-    typedef typename iterator_traits<_BidirectionalIterator>::value_type value_type;
-    _BidirectionalIterator __lm1 = _VSTD::prev(__last);
-    value_type __tmp = _VSTD::move(*__lm1);
-    _BidirectionalIterator __fp1 = _VSTD::move_backward(__first, __lm1, __last);
-    *__first = _VSTD::move(__tmp);
-    return __fp1;
-}
-
-template <class _ForwardIterator>
-_ForwardIterator
-__rotate_forward(_ForwardIterator __first, _ForwardIterator __middle, _ForwardIterator __last)
-{
-    _ForwardIterator __i = __middle;
-    while (true)
-    {
-        swap(*__first, *__i);
-        ++__first;
-        if (++__i == __last)
-            break;
-        if (__first == __middle)
-            __middle = __i;
-    }
-    _ForwardIterator __r = __first;
-    if (__first != __middle)
-    {
-        __i = __middle;
-        while (true)
-        {
-            swap(*__first, *__i);
-            ++__first;
-            if (++__i == __last)
-            {
-                if (__first == __middle)
-                    break;
-                __i = __middle;
-            }
-            else if (__first == __middle)
-                __middle = __i;
-        }
-    }
-    return __r;
-}
-
-template<typename _Integral>
-inline _LIBCPP_INLINE_VISIBILITY
-_Integral
-__algo_gcd(_Integral __x, _Integral __y)
-{
-    do
-    {
-        _Integral __t = __x % __y;
-        __x = __y;
-        __y = __t;
-    } while (__y);
-    return __x;
-}
-
-template<typename _RandomAccessIterator>
-_RandomAccessIterator
-__rotate_gcd(_RandomAccessIterator __first, _RandomAccessIterator __middle, _RandomAccessIterator __last)
-{
-    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
-    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
-
-    const difference_type __m1 = __middle - __first;
-    const difference_type __m2 = __last - __middle;
-    if (__m1 == __m2)
-    {
-        _VSTD::swap_ranges(__first, __middle, __middle);
-        return __middle;
-    }
-    const difference_type __g = _VSTD::__algo_gcd(__m1, __m2);
-    for (_RandomAccessIterator __p = __first + __g; __p != __first;)
-    {
-        value_type __t(_VSTD::move(*--__p));
-        _RandomAccessIterator __p1 = __p;
-        _RandomAccessIterator __p2 = __p1 + __m1;
-        do
-        {
-            *__p1 = _VSTD::move(*__p2);
-            __p1 = __p2;
-            const difference_type __d = __last - __p2;
-            if (__m1 < __d)
-                __p2 += __m1;
-            else
-                __p2 = __first + (__m1 - __d);
-        } while (__p2 != __p);
-        *__p1 = _VSTD::move(__t);
-    }
-    return __first + __m2;
-}
-
-template <class _ForwardIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-_ForwardIterator
-__rotate(_ForwardIterator __first, _ForwardIterator __middle, _ForwardIterator __last,
-         _VSTD::forward_iterator_tag)
-{
-    typedef typename _VSTD::iterator_traits<_ForwardIterator>::value_type value_type;
-    if (_VSTD::is_trivially_move_assignable<value_type>::value)
-    {
-        if (_VSTD::next(__first) == __middle)
-            return _VSTD::__rotate_left(__first, __last);
-    }
-    return _VSTD::__rotate_forward(__first, __middle, __last);
-}
-
-template <class _BidirectionalIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-_BidirectionalIterator
-__rotate(_BidirectionalIterator __first, _BidirectionalIterator __middle, _BidirectionalIterator __last,
-         _VSTD::bidirectional_iterator_tag)
-{
-    typedef typename _VSTD::iterator_traits<_BidirectionalIterator>::value_type value_type;
-    if (_VSTD::is_trivially_move_assignable<value_type>::value)
-    {
-        if (_VSTD::next(__first) == __middle)
-            return _VSTD::__rotate_left(__first, __last);
-        if (_VSTD::next(__middle) == __last)
-            return _VSTD::__rotate_right(__first, __last);
-    }
-    return _VSTD::__rotate_forward(__first, __middle, __last);
-}
-
-template <class _RandomAccessIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-_RandomAccessIterator
-__rotate(_RandomAccessIterator __first, _RandomAccessIterator __middle, _RandomAccessIterator __last,
-         _VSTD::random_access_iterator_tag)
-{
-    typedef typename _VSTD::iterator_traits<_RandomAccessIterator>::value_type value_type;
-    if (_VSTD::is_trivially_move_assignable<value_type>::value)
-    {
-        if (_VSTD::next(__first) == __middle)
-            return _VSTD::__rotate_left(__first, __last);
-        if (_VSTD::next(__middle) == __last)
-            return _VSTD::__rotate_right(__first, __last);
-        return _VSTD::__rotate_gcd(__first, __middle, __last);
-    }
-    return _VSTD::__rotate_forward(__first, __middle, __last);
-}
-
-template <class _ForwardIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-_ForwardIterator
-rotate(_ForwardIterator __first, _ForwardIterator __middle, _ForwardIterator __last)
-{
-    if (__first == __middle)
-        return __last;
-    if (__middle == __last)
-        return __first;
-    return _VSTD::__rotate(__first, __middle, __last,
-                           typename _VSTD::iterator_traits<_ForwardIterator>::iterator_category());
-}
-
-// rotate_copy
-
-template <class _ForwardIterator, class _OutputIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-_OutputIterator
-rotate_copy(_ForwardIterator __first, _ForwardIterator __middle, _ForwardIterator __last, _OutputIterator __result)
-{
-    return _VSTD::copy(__first, __middle, _VSTD::copy(__middle, __last, __result));
-}
-
-// min_element
-
-template <class _ForwardIterator, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-_ForwardIterator
-min_element(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp)
-{
-    static_assert(__is_forward_iterator<_ForwardIterator>::value,
-        "std::min_element requires a ForwardIterator");
-    if (__first != __last)
-    {
-        _ForwardIterator __i = __first;
-        while (++__i != __last)
-            if (__comp(*__i, *__first))
-                __first = __i;
-    }
-    return __first;
-}
-
-template <class _ForwardIterator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-_ForwardIterator
-min_element(_ForwardIterator __first, _ForwardIterator __last)
-{
-    return _VSTD::min_element(__first, __last,
-              __less<typename iterator_traits<_ForwardIterator>::value_type>());
-}
-
-// min
-
-template <class _Tp, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-const _Tp&
-min(const _Tp& __a, const _Tp& __b, _Compare __comp)
-{
-    return __comp(__b, __a) ? __b : __a;
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-const _Tp&
-min(const _Tp& __a, const _Tp& __b)
-{
-    return _VSTD::min(__a, __b, __less<_Tp>());
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template<class _Tp, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-_Tp
-min(initializer_list<_Tp> __t, _Compare __comp)
-{
-    return *_VSTD::min_element(__t.begin(), __t.end(), __comp);
-}
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-_Tp
-min(initializer_list<_Tp> __t)
-{
-    return *_VSTD::min_element(__t.begin(), __t.end(), __less<_Tp>());
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-// max_element
-
-template <class _ForwardIterator, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-_ForwardIterator
-max_element(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp)
-{
-    static_assert(__is_forward_iterator<_ForwardIterator>::value,
-        "std::max_element requires a ForwardIterator");
-    if (__first != __last)
-    {
-        _ForwardIterator __i = __first;
-        while (++__i != __last)
-            if (__comp(*__first, *__i))
-                __first = __i;
-    }
-    return __first;
-}
-
-
-template <class _ForwardIterator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-_ForwardIterator
-max_element(_ForwardIterator __first, _ForwardIterator __last)
-{
-    return _VSTD::max_element(__first, __last,
-              __less<typename iterator_traits<_ForwardIterator>::value_type>());
-}
-
-// max
-
-template <class _Tp, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-const _Tp&
-max(const _Tp& __a, const _Tp& __b, _Compare __comp)
-{
-    return __comp(__a, __b) ? __b : __a;
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-const _Tp&
-max(const _Tp& __a, const _Tp& __b)
-{
-    return _VSTD::max(__a, __b, __less<_Tp>());
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template<class _Tp, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-_Tp
-max(initializer_list<_Tp> __t, _Compare __comp)
-{
-    return *_VSTD::max_element(__t.begin(), __t.end(), __comp);
-}
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-_Tp
-max(initializer_list<_Tp> __t)
-{
-    return *_VSTD::max_element(__t.begin(), __t.end(), __less<_Tp>());
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-#if _LIBCPP_STD_VER > 14
-// clamp
-template<class _Tp, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-const _Tp&
-clamp(const _Tp& __v, const _Tp& __lo, const _Tp& __hi, _Compare __comp)
-{
-    _LIBCPP_ASSERT(!__comp(__hi, __lo), "Bad bounds passed to std::clamp");
-    return __comp(__v, __lo) ? __lo : __comp(__hi, __v) ? __hi : __v;
-
-}
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-const _Tp&
-clamp(const _Tp& __v, const _Tp& __lo, const _Tp& __hi)
-{
-    return _VSTD::clamp(__v, __lo, __hi, __less<_Tp>());
-}
-#endif
-
-// minmax_element
-
-template <class _ForwardIterator, class _Compare>
-_LIBCPP_CONSTEXPR_AFTER_CXX11
-std::pair<_ForwardIterator, _ForwardIterator>
-minmax_element(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp)
-{
-  static_assert(__is_forward_iterator<_ForwardIterator>::value,
-        "std::minmax_element requires a ForwardIterator");
-  std::pair<_ForwardIterator, _ForwardIterator> __result(__first, __first);
-  if (__first != __last)
-  {
-      if (++__first != __last)
-      {
-          if (__comp(*__first, *__result.first))
-              __result.first = __first;
-          else
-              __result.second = __first;
-          while (++__first != __last)
-          {
-              _ForwardIterator __i = __first;
-              if (++__first == __last)
-              {
-                  if (__comp(*__i, *__result.first))
-                      __result.first = __i;
-                  else if (!__comp(*__i, *__result.second))
-                      __result.second = __i;
-                  break;
-              }
-              else
-              {
-                  if (__comp(*__first, *__i))
-                  {
-                      if (__comp(*__first, *__result.first))
-                          __result.first = __first;
-                      if (!__comp(*__i, *__result.second))
-                          __result.second = __i;
-                  }
-                  else
-                  {
-                      if (__comp(*__i, *__result.first))
-                          __result.first = __i;
-                      if (!__comp(*__first, *__result.second))
-                          __result.second = __first;
-                  }
-              }
-          }
-      }
-  }
-  return __result;
-}
-
-template <class _ForwardIterator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-std::pair<_ForwardIterator, _ForwardIterator>
-minmax_element(_ForwardIterator __first, _ForwardIterator __last)
-{
-    return _VSTD::minmax_element(__first, __last,
-              __less<typename iterator_traits<_ForwardIterator>::value_type>());
-}
-
-// minmax
-
-template<class _Tp, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-pair<const _Tp&, const _Tp&>
-minmax(const _Tp& __a, const _Tp& __b, _Compare __comp)
-{
-    return __comp(__b, __a) ? pair<const _Tp&, const _Tp&>(__b, __a) :
-                              pair<const _Tp&, const _Tp&>(__a, __b);
-}
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-pair<const _Tp&, const _Tp&>
-minmax(const _Tp& __a, const _Tp& __b)
-{
-    return _VSTD::minmax(__a, __b, __less<_Tp>());
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template<class _Tp, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-pair<_Tp, _Tp>
-minmax(initializer_list<_Tp> __t, _Compare __comp)
-{
-    typedef typename initializer_list<_Tp>::const_iterator _Iter;
-    _Iter __first = __t.begin();
-    _Iter __last  = __t.end();
-    std::pair<_Tp, _Tp> __result(*__first, *__first);
-
-    ++__first;
-    if (__t.size() % 2 == 0)
-    {
-        if (__comp(*__first,  __result.first))
-            __result.first  = *__first;
-        else
-            __result.second = *__first;
-        ++__first;
-    }
-
-    while (__first != __last)
-    {
-        _Tp __prev = *__first++;
-        if (__comp(*__first, __prev)) {
-            if ( __comp(*__first, __result.first)) __result.first  = *__first;
-            if (!__comp(__prev, __result.second))  __result.second = __prev;
-            }
-        else {
-            if ( __comp(__prev, __result.first))    __result.first  = __prev;
-            if (!__comp(*__first, __result.second)) __result.second = *__first;
-            }
-
-        __first++;
-    }
-    return __result;
-}
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-pair<_Tp, _Tp>
-minmax(initializer_list<_Tp> __t)
-{
-    return _VSTD::minmax(__t, __less<_Tp>());
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-// random_shuffle
-
-// __independent_bits_engine
-
-template <unsigned long long _Xp, size_t _Rp>
-struct __log2_imp
-{
-    static const size_t value = _Xp & ((unsigned long long)(1) << _Rp) ? _Rp
-                                           : __log2_imp<_Xp, _Rp - 1>::value;
-};
-
-template <unsigned long long _Xp>
-struct __log2_imp<_Xp, 0>
-{
-    static const size_t value = 0;
-};
-
-template <size_t _Rp>
-struct __log2_imp<0, _Rp>
-{
-    static const size_t value = _Rp + 1;
-};
-
-template <class _UIntType, _UIntType _Xp>
-struct __log2
-{
-    static const size_t value = __log2_imp<_Xp,
-                                         sizeof(_UIntType) * __CHAR_BIT__ - 1>::value;
-};
-
-template<class _Engine, class _UIntType>
-class __independent_bits_engine
-{
-public:
-    // types
-    typedef _UIntType result_type;
-
-private:
-    typedef typename _Engine::result_type _Engine_result_type;
-    typedef typename conditional
-        <
-            sizeof(_Engine_result_type) <= sizeof(result_type),
-                result_type,
-                _Engine_result_type
-        >::type _Working_result_type;
-
-    _Engine& __e_;
-    size_t __w_;
-    size_t __w0_;
-    size_t __n_;
-    size_t __n0_;
-    _Working_result_type __y0_;
-    _Working_result_type __y1_;
-    _Engine_result_type __mask0_;
-    _Engine_result_type __mask1_;
-
-#ifdef _LIBCPP_CXX03_LANG
-    static const _Working_result_type _Rp = _Engine::_Max - _Engine::_Min
-                                          + _Working_result_type(1);
-#else
-    static _LIBCPP_CONSTEXPR const _Working_result_type _Rp = _Engine::max() - _Engine::min()
-                                                      + _Working_result_type(1);
-#endif
-    static _LIBCPP_CONSTEXPR const size_t __m = __log2<_Working_result_type, _Rp>::value;
-    static _LIBCPP_CONSTEXPR const size_t _WDt = numeric_limits<_Working_result_type>::digits;
-    static _LIBCPP_CONSTEXPR const size_t _EDt = numeric_limits<_Engine_result_type>::digits;
-
-public:
-    // constructors and seeding functions
-    __independent_bits_engine(_Engine& __e, size_t __w);
-
-    // generating functions
-    result_type operator()() {return __eval(integral_constant<bool, _Rp != 0>());}
-
-private:
-    result_type __eval(false_type);
-    result_type __eval(true_type);
-};
-
-template<class _Engine, class _UIntType>
-__independent_bits_engine<_Engine, _UIntType>
-    ::__independent_bits_engine(_Engine& __e, size_t __w)
-        : __e_(__e),
-          __w_(__w)
-{
-    __n_ = __w_ / __m + (__w_ % __m != 0);
-    __w0_ = __w_ / __n_;
-    if (_Rp == 0)
-        __y0_ = _Rp;
-    else if (__w0_ < _WDt)
-        __y0_ = (_Rp >> __w0_) << __w0_;
-    else
-        __y0_ = 0;
-    if (_Rp - __y0_ > __y0_ / __n_)
-    {
-        ++__n_;
-        __w0_ = __w_ / __n_;
-        if (__w0_ < _WDt)
-            __y0_ = (_Rp >> __w0_) << __w0_;
-        else
-            __y0_ = 0;
-    }
-    __n0_ = __n_ - __w_ % __n_;
-    if (__w0_ < _WDt - 1)
-        __y1_ = (_Rp >> (__w0_ + 1)) << (__w0_ + 1);
-    else
-        __y1_ = 0;
-    __mask0_ = __w0_ > 0 ? _Engine_result_type(~0) >> (_EDt - __w0_) :
-                          _Engine_result_type(0);
-    __mask1_ = __w0_ < _EDt - 1 ?
-                               _Engine_result_type(~0) >> (_EDt - (__w0_ + 1)) :
-                               _Engine_result_type(~0);
-}
-
-template<class _Engine, class _UIntType>
-inline
-_UIntType
-__independent_bits_engine<_Engine, _UIntType>::__eval(false_type)
-{
-    return static_cast<result_type>(__e_() & __mask0_);
-}
-
-template<class _Engine, class _UIntType>
-_UIntType
-__independent_bits_engine<_Engine, _UIntType>::__eval(true_type)
-{
-    const size_t _WRt = numeric_limits<result_type>::digits;
-    result_type _Sp = 0;
-    for (size_t __k = 0; __k < __n0_; ++__k)
-    {
-        _Engine_result_type __u;
-        do
-        {
-            __u = __e_() - _Engine::min();
-        } while (__u >= __y0_);
-        if (__w0_ < _WRt)
-            _Sp <<= __w0_;
-        else
-            _Sp = 0;
-        _Sp += __u & __mask0_;
-    }
-    for (size_t __k = __n0_; __k < __n_; ++__k)
-    {
-        _Engine_result_type __u;
-        do
-        {
-            __u = __e_() - _Engine::min();
-        } while (__u >= __y1_);
-        if (__w0_ < _WRt - 1)
-            _Sp <<= __w0_ + 1;
-        else
-            _Sp = 0;
-        _Sp += __u & __mask1_;
-    }
-    return _Sp;
-}
-
-// uniform_int_distribution
-
-template<class _IntType = int>
-class uniform_int_distribution
-{
-public:
-    // types
-    typedef _IntType result_type;
-
-    class param_type
-    {
-        result_type __a_;
-        result_type __b_;
-    public:
-        typedef uniform_int_distribution distribution_type;
-
-        explicit param_type(result_type __a = 0,
-                            result_type __b = numeric_limits<result_type>::max())
-            : __a_(__a), __b_(__b) {}
-
-        result_type a() const {return __a_;}
-        result_type b() const {return __b_;}
-
-        friend bool operator==(const param_type& __x, const param_type& __y)
-            {return __x.__a_ == __y.__a_ && __x.__b_ == __y.__b_;}
-        friend bool operator!=(const param_type& __x, const param_type& __y)
-            {return !(__x == __y);}
-    };
-
-private:
-    param_type __p_;
-
-public:
-    // constructors and reset functions
-    explicit uniform_int_distribution(result_type __a = 0,
-                                      result_type __b = numeric_limits<result_type>::max())
-        : __p_(param_type(__a, __b)) {}
-    explicit uniform_int_distribution(const param_type& __p) : __p_(__p) {}
-    void reset() {}
-
-    // generating functions
-    template<class _URNG> result_type operator()(_URNG& __g)
-        {return (*this)(__g, __p_);}
-    template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
-
-    // property functions
-    result_type a() const {return __p_.a();}
-    result_type b() const {return __p_.b();}
-
-    param_type param() const {return __p_;}
-    void param(const param_type& __p) {__p_ = __p;}
-
-    result_type min() const {return a();}
-    result_type max() const {return b();}
-
-    friend bool operator==(const uniform_int_distribution& __x,
-                           const uniform_int_distribution& __y)
-        {return __x.__p_ == __y.__p_;}
-    friend bool operator!=(const uniform_int_distribution& __x,
-                           const uniform_int_distribution& __y)
-            {return !(__x == __y);}
-};
-
-template<class _IntType>
-template<class _URNG>
-typename uniform_int_distribution<_IntType>::result_type
-uniform_int_distribution<_IntType>::operator()(_URNG& __g, const param_type& __p)
-_LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK
-{
-    typedef typename conditional<sizeof(result_type) <= sizeof(uint32_t),
-                                            uint32_t, uint64_t>::type _UIntType;
-    const _UIntType _Rp = _UIntType(__p.b()) - _UIntType(__p.a()) + _UIntType(1);
-    if (_Rp == 1)
-        return __p.a();
-    const size_t _Dt = numeric_limits<_UIntType>::digits;
-    typedef __independent_bits_engine<_URNG, _UIntType> _Eng;
-    if (_Rp == 0)
-        return static_cast<result_type>(_Eng(__g, _Dt)());
-    size_t __w = _Dt - __clz(_Rp) - 1;
-    if ((_Rp & (std::numeric_limits<_UIntType>::max() >> (_Dt - __w))) != 0)
-        ++__w;
-    _Eng __e(__g, __w);
-    _UIntType __u;
-    do
-    {
-        __u = __e();
-    } while (__u >= _Rp);
-    return static_cast<result_type>(__u + __p.a());
-}
-
-#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_RANDOM_SHUFFLE) \
-  || defined(_LIBCPP_BUILDING_LIBRARY)
-class _LIBCPP_TYPE_VIS __rs_default;
-
-_LIBCPP_FUNC_VIS __rs_default __rs_get();
-
-class _LIBCPP_TYPE_VIS __rs_default
-{
-    static unsigned __c_;
-
-    __rs_default();
-public:
-    typedef uint_fast32_t result_type;
-
-    static const result_type _Min = 0;
-    static const result_type _Max = 0xFFFFFFFF;
-
-    __rs_default(const __rs_default&);
-    ~__rs_default();
-
-    result_type operator()();
-
-    static _LIBCPP_CONSTEXPR result_type min() {return _Min;}
-    static _LIBCPP_CONSTEXPR result_type max() {return _Max;}
-
-    friend _LIBCPP_FUNC_VIS __rs_default __rs_get();
-};
-
-_LIBCPP_FUNC_VIS __rs_default __rs_get();
-
-template <class _RandomAccessIterator>
-_LIBCPP_DEPRECATED_IN_CXX14 void
-random_shuffle(_RandomAccessIterator __first, _RandomAccessIterator __last)
-{
-    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
-    typedef uniform_int_distribution<ptrdiff_t> _Dp;
-    typedef typename _Dp::param_type _Pp;
-    difference_type __d = __last - __first;
-    if (__d > 1)
-    {
-        _Dp __uid;
-        __rs_default __g = __rs_get();
-        for (--__last, --__d; __first < __last; ++__first, --__d)
-        {
-            difference_type __i = __uid(__g, _Pp(0, __d));
-            if (__i != difference_type(0))
-                swap(*__first, *(__first + __i));
-        }
-    }
-}
-
-template <class _RandomAccessIterator, class _RandomNumberGenerator>
-_LIBCPP_DEPRECATED_IN_CXX14 void
-random_shuffle(_RandomAccessIterator __first, _RandomAccessIterator __last,
-#ifndef _LIBCPP_CXX03_LANG
-               _RandomNumberGenerator&& __rand)
-#else
-               _RandomNumberGenerator& __rand)
-#endif
-{
-    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
-    difference_type __d = __last - __first;
-    if (__d > 1)
-    {
-        for (--__last; __first < __last; ++__first, --__d)
-        {
-            difference_type __i = __rand(__d);
-            if (__i != difference_type(0))
-              swap(*__first, *(__first + __i));
-        }
-    }
-}
-#endif
-
-template <class _PopulationIterator, class _SampleIterator, class _Distance,
-          class _UniformRandomNumberGenerator>
-_LIBCPP_INLINE_VISIBILITY
-_SampleIterator __sample(_PopulationIterator __first,
-                         _PopulationIterator __last, _SampleIterator __output_iter,
-                         _Distance __n,
-                         _UniformRandomNumberGenerator & __g,
-                         input_iterator_tag) {
-
-  _Distance __k = 0;
-  for (; __first != __last && __k < __n; ++__first, (void)++__k)
-    __output_iter[__k] = *__first;
-  _Distance __sz = __k;
-  for (; __first != __last; ++__first, (void)++__k) {
-    _Distance __r = _VSTD::uniform_int_distribution<_Distance>(0, __k)(__g);
-    if (__r < __sz)
-      __output_iter[__r] = *__first;
-  }
-  return __output_iter + _VSTD::min(__n, __k);
-}
-
-template <class _PopulationIterator, class _SampleIterator, class _Distance,
-          class _UniformRandomNumberGenerator>
-_LIBCPP_INLINE_VISIBILITY
-_SampleIterator __sample(_PopulationIterator __first,
-                         _PopulationIterator __last, _SampleIterator __output_iter,
-                         _Distance __n,
-                         _UniformRandomNumberGenerator& __g,
-                         forward_iterator_tag) {
-  _Distance __unsampled_sz = _VSTD::distance(__first, __last);
-  for (__n = _VSTD::min(__n, __unsampled_sz); __n != 0; ++__first) {
-    _Distance __r =
-        _VSTD::uniform_int_distribution<_Distance>(0, --__unsampled_sz)(__g);
-    if (__r < __n) {
-      *__output_iter++ = *__first;
-      --__n;
-    }
-  }
-  return __output_iter;
-}
-
-template <class _PopulationIterator, class _SampleIterator, class _Distance,
-          class _UniformRandomNumberGenerator>
-_LIBCPP_INLINE_VISIBILITY
-_SampleIterator __sample(_PopulationIterator __first,
-                         _PopulationIterator __last, _SampleIterator __output_iter,
-                         _Distance __n, _UniformRandomNumberGenerator& __g) {
-  typedef typename iterator_traits<_PopulationIterator>::iterator_category
-        _PopCategory;
-  typedef typename iterator_traits<_PopulationIterator>::difference_type
-        _Difference;
-  static_assert(__is_forward_iterator<_PopulationIterator>::value ||
-                __is_random_access_iterator<_SampleIterator>::value,
-                "SampleIterator must meet the requirements of RandomAccessIterator");
-  typedef typename common_type<_Distance, _Difference>::type _CommonType;
-  _LIBCPP_ASSERT(__n >= 0, "N must be a positive number.");
-  return _VSTD::__sample(
-      __first, __last, __output_iter, _CommonType(__n),
-      __g, _PopCategory());
-}
-
-#if _LIBCPP_STD_VER > 14
-template <class _PopulationIterator, class _SampleIterator, class _Distance,
-          class _UniformRandomNumberGenerator>
-inline _LIBCPP_INLINE_VISIBILITY
-_SampleIterator sample(_PopulationIterator __first,
-                       _PopulationIterator __last, _SampleIterator __output_iter,
-                       _Distance __n, _UniformRandomNumberGenerator&& __g) {
-    return _VSTD::__sample(__first, __last, __output_iter, __n, __g);
-}
-#endif // _LIBCPP_STD_VER > 14
-
-template<class _RandomAccessIterator, class _UniformRandomNumberGenerator>
-    void shuffle(_RandomAccessIterator __first, _RandomAccessIterator __last,
-#ifndef _LIBCPP_CXX03_LANG
-                 _UniformRandomNumberGenerator&& __g)
-#else
-                 _UniformRandomNumberGenerator& __g)
-#endif
-{
-    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
-    typedef uniform_int_distribution<ptrdiff_t> _Dp;
-    typedef typename _Dp::param_type _Pp;
-    difference_type __d = __last - __first;
-    if (__d > 1)
-    {
-        _Dp __uid;
-        for (--__last, --__d; __first < __last; ++__first, --__d)
-        {
-            difference_type __i = __uid(__g, _Pp(0, __d));
-            if (__i != difference_type(0))
-                swap(*__first, *(__first + __i));
-        }
-    }
-}
-
-template <class _InputIterator, class _Predicate>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
-is_partitioned(_InputIterator __first, _InputIterator __last, _Predicate __pred)
-{
-    for (; __first != __last; ++__first)
-        if (!__pred(*__first))
-            break;
-    if ( __first == __last )
-        return true;
-    ++__first;
-    for (; __first != __last; ++__first)
-        if (__pred(*__first))
-            return false;
-    return true;
-}
-
-// partition
-
-template <class _Predicate, class _ForwardIterator>
-_ForwardIterator
-__partition(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred, forward_iterator_tag)
-{
-    while (true)
-    {
-        if (__first == __last)
-            return __first;
-        if (!__pred(*__first))
-            break;
-        ++__first;
-    }
-    for (_ForwardIterator __p = __first; ++__p != __last;)
-    {
-        if (__pred(*__p))
-        {
-            swap(*__first, *__p);
-            ++__first;
-        }
-    }
-    return __first;
-}
-
-template <class _Predicate, class _BidirectionalIterator>
-_BidirectionalIterator
-__partition(_BidirectionalIterator __first, _BidirectionalIterator __last, _Predicate __pred,
-            bidirectional_iterator_tag)
-{
-    while (true)
-    {
-        while (true)
-        {
-            if (__first == __last)
-                return __first;
-            if (!__pred(*__first))
-                break;
-            ++__first;
-        }
-        do
-        {
-            if (__first == --__last)
-                return __first;
-        } while (!__pred(*__last));
-        swap(*__first, *__last);
-        ++__first;
-    }
-}
-
-template <class _ForwardIterator, class _Predicate>
-inline _LIBCPP_INLINE_VISIBILITY
-_ForwardIterator
-partition(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred)
-{
-    return _VSTD::__partition<typename add_lvalue_reference<_Predicate>::type>
-                            (__first, __last, __pred, typename iterator_traits<_ForwardIterator>::iterator_category());
-}
-
-// partition_copy
-
-template <class _InputIterator, class _OutputIterator1,
-          class _OutputIterator2, class _Predicate>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 pair<_OutputIterator1, _OutputIterator2>
-partition_copy(_InputIterator __first, _InputIterator __last,
-               _OutputIterator1 __out_true, _OutputIterator2 __out_false,
-               _Predicate __pred)
-{
-    for (; __first != __last; ++__first)
-    {
-        if (__pred(*__first))
-        {
-            *__out_true = *__first;
-            ++__out_true;
-        }
-        else
-        {
-            *__out_false = *__first;
-            ++__out_false;
-        }
-    }
-    return pair<_OutputIterator1, _OutputIterator2>(__out_true, __out_false);
-}
-
-// partition_point
-
-template<class _ForwardIterator, class _Predicate>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
-partition_point(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred)
-{
-    typedef typename iterator_traits<_ForwardIterator>::difference_type difference_type;
-    difference_type __len = _VSTD::distance(__first, __last);
-    while (__len != 0)
-    {
-        difference_type __l2 = _VSTD::__half_positive(__len);
-        _ForwardIterator __m = __first;
-        _VSTD::advance(__m, __l2);
-        if (__pred(*__m))
-        {
-            __first = ++__m;
-            __len -= __l2 + 1;
-        }
-        else
-            __len = __l2;
-    }
-    return __first;
-}
-
-// stable_partition
-
-template <class _Predicate, class _ForwardIterator, class _Distance, class _Pair>
-_ForwardIterator
-__stable_partition(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred,
-                   _Distance __len, _Pair __p, forward_iterator_tag __fit)
-{
-    // *__first is known to be false
-    // __len >= 1
-    if (__len == 1)
-        return __first;
-    if (__len == 2)
-    {
-        _ForwardIterator __m = __first;
-        if (__pred(*++__m))
-        {
-            swap(*__first, *__m);
-            return __m;
-        }
-        return __first;
-    }
-    if (__len <= __p.second)
-    {   // The buffer is big enough to use
-        typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
-        __destruct_n __d(0);
-        unique_ptr<value_type, __destruct_n&> __h(__p.first, __d);
-        // Move the falses into the temporary buffer, and the trues to the front of the line
-        // Update __first to always point to the end of the trues
-        value_type* __t = __p.first;
-        ::new(__t) value_type(_VSTD::move(*__first));
-        __d.__incr((value_type*)0);
-        ++__t;
-        _ForwardIterator __i = __first;
-        while (++__i != __last)
-        {
-            if (__pred(*__i))
-            {
-                *__first = _VSTD::move(*__i);
-                ++__first;
-            }
-            else
-            {
-                ::new(__t) value_type(_VSTD::move(*__i));
-                __d.__incr((value_type*)0);
-                ++__t;
-            }
-        }
-        // All trues now at start of range, all falses in buffer
-        // Move falses back into range, but don't mess up __first which points to first false
-        __i = __first;
-        for (value_type* __t2 = __p.first; __t2 < __t; ++__t2, ++__i)
-            *__i = _VSTD::move(*__t2);
-        // __h destructs moved-from values out of the temp buffer, but doesn't deallocate buffer
-        return __first;
-    }
-    // Else not enough buffer, do in place
-    // __len >= 3
-    _ForwardIterator __m = __first;
-    _Distance __len2 = __len / 2;  // __len2 >= 2
-    _VSTD::advance(__m, __len2);
-    // recurse on [__first, __m), *__first know to be false
-    // F?????????????????
-    // f       m         l
-    typedef typename add_lvalue_reference<_Predicate>::type _PredRef;
-    _ForwardIterator __first_false = __stable_partition<_PredRef>(__first, __m, __pred, __len2, __p, __fit);
-    // TTTFFFFF??????????
-    // f  ff   m         l
-    // recurse on [__m, __last], except increase __m until *(__m) is false, *__last know to be true
-    _ForwardIterator __m1 = __m;
-    _ForwardIterator __second_false = __last;
-    _Distance __len_half = __len - __len2;
-    while (__pred(*__m1))
-    {
-        if (++__m1 == __last)
-            goto __second_half_done;
-        --__len_half;
-    }
-    // TTTFFFFFTTTF??????
-    // f  ff   m  m1     l
-    __second_false = __stable_partition<_PredRef>(__m1, __last, __pred, __len_half, __p, __fit);
-__second_half_done:
-    // TTTFFFFFTTTTTFFFFF
-    // f  ff   m    sf   l
-    return _VSTD::rotate(__first_false, __m, __second_false);
-    // TTTTTTTTFFFFFFFFFF
-    //         |
-}
-
-struct __return_temporary_buffer
-{
-    template <class _Tp>
-    _LIBCPP_INLINE_VISIBILITY void operator()(_Tp* __p) const {_VSTD::return_temporary_buffer(__p);}
-};
-
-template <class _Predicate, class _ForwardIterator>
-_ForwardIterator
-__stable_partition(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred,
-                   forward_iterator_tag)
-{
-    const unsigned __alloc_limit = 3;  // might want to make this a function of trivial assignment
-    // Either prove all true and return __first or point to first false
-    while (true)
-    {
-        if (__first == __last)
-            return __first;
-        if (!__pred(*__first))
-            break;
-        ++__first;
-    }
-    // We now have a reduced range [__first, __last)
-    // *__first is known to be false
-    typedef typename iterator_traits<_ForwardIterator>::difference_type difference_type;
-    typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
-    difference_type __len = _VSTD::distance(__first, __last);
-    pair<value_type*, ptrdiff_t> __p(0, 0);
-    unique_ptr<value_type, __return_temporary_buffer> __h;
-    if (__len >= __alloc_limit)
-    {
-        __p = _VSTD::get_temporary_buffer<value_type>(__len);
-        __h.reset(__p.first);
-    }
-    return __stable_partition<typename add_lvalue_reference<_Predicate>::type>
-                             (__first, __last, __pred, __len, __p, forward_iterator_tag());
-}
-
-template <class _Predicate, class _BidirectionalIterator, class _Distance, class _Pair>
-_BidirectionalIterator
-__stable_partition(_BidirectionalIterator __first, _BidirectionalIterator __last, _Predicate __pred,
-                   _Distance __len, _Pair __p, bidirectional_iterator_tag __bit)
-{
-    // *__first is known to be false
-    // *__last is known to be true
-    // __len >= 2
-    if (__len == 2)
-    {
-        swap(*__first, *__last);
-        return __last;
-    }
-    if (__len == 3)
-    {
-        _BidirectionalIterator __m = __first;
-        if (__pred(*++__m))
-        {
-            swap(*__first, *__m);
-            swap(*__m, *__last);
-            return __last;
-        }
-        swap(*__m, *__last);
-        swap(*__first, *__m);
-        return __m;
-    }
-    if (__len <= __p.second)
-    {   // The buffer is big enough to use
-        typedef typename iterator_traits<_BidirectionalIterator>::value_type value_type;
-        __destruct_n __d(0);
-        unique_ptr<value_type, __destruct_n&> __h(__p.first, __d);
-        // Move the falses into the temporary buffer, and the trues to the front of the line
-        // Update __first to always point to the end of the trues
-        value_type* __t = __p.first;
-        ::new(__t) value_type(_VSTD::move(*__first));
-        __d.__incr((value_type*)0);
-        ++__t;
-        _BidirectionalIterator __i = __first;
-        while (++__i != __last)
-        {
-            if (__pred(*__i))
-            {
-                *__first = _VSTD::move(*__i);
-                ++__first;
-            }
-            else
-            {
-                ::new(__t) value_type(_VSTD::move(*__i));
-                __d.__incr((value_type*)0);
-                ++__t;
-            }
-        }
-        // move *__last, known to be true
-        *__first = _VSTD::move(*__i);
-        __i = ++__first;
-        // All trues now at start of range, all falses in buffer
-        // Move falses back into range, but don't mess up __first which points to first false
-        for (value_type* __t2 = __p.first; __t2 < __t; ++__t2, ++__i)
-            *__i = _VSTD::move(*__t2);
-        // __h destructs moved-from values out of the temp buffer, but doesn't deallocate buffer
-        return __first;
-    }
-    // Else not enough buffer, do in place
-    // __len >= 4
-    _BidirectionalIterator __m = __first;
-    _Distance __len2 = __len / 2;  // __len2 >= 2
-    _VSTD::advance(__m, __len2);
-    // recurse on [__first, __m-1], except reduce __m-1 until *(__m-1) is true, *__first know to be false
-    // F????????????????T
-    // f       m        l
-    _BidirectionalIterator __m1 = __m;
-    _BidirectionalIterator __first_false = __first;
-    _Distance __len_half = __len2;
-    while (!__pred(*--__m1))
-    {
-        if (__m1 == __first)
-            goto __first_half_done;
-        --__len_half;
-    }
-    // F???TFFF?????????T
-    // f   m1  m        l
-    typedef typename add_lvalue_reference<_Predicate>::type _PredRef;
-    __first_false = __stable_partition<_PredRef>(__first, __m1, __pred, __len_half, __p, __bit);
-__first_half_done:
-    // TTTFFFFF?????????T
-    // f  ff   m        l
-    // recurse on [__m, __last], except increase __m until *(__m) is false, *__last know to be true
-    __m1 = __m;
-    _BidirectionalIterator __second_false = __last;
-    ++__second_false;
-    __len_half = __len - __len2;
-    while (__pred(*__m1))
-    {
-        if (++__m1 == __last)
-            goto __second_half_done;
-        --__len_half;
-    }
-    // TTTFFFFFTTTF?????T
-    // f  ff   m  m1    l
-    __second_false = __stable_partition<_PredRef>(__m1, __last, __pred, __len_half, __p, __bit);
-__second_half_done:
-    // TTTFFFFFTTTTTFFFFF
-    // f  ff   m    sf  l
-    return _VSTD::rotate(__first_false, __m, __second_false);
-    // TTTTTTTTFFFFFFFFFF
-    //         |
-}
-
-template <class _Predicate, class _BidirectionalIterator>
-_BidirectionalIterator
-__stable_partition(_BidirectionalIterator __first, _BidirectionalIterator __last, _Predicate __pred,
-                   bidirectional_iterator_tag)
-{
-    typedef typename iterator_traits<_BidirectionalIterator>::difference_type difference_type;
-    typedef typename iterator_traits<_BidirectionalIterator>::value_type value_type;
-    const difference_type __alloc_limit = 4;  // might want to make this a function of trivial assignment
-    // Either prove all true and return __first or point to first false
-    while (true)
-    {
-        if (__first == __last)
-            return __first;
-        if (!__pred(*__first))
-            break;
-        ++__first;
-    }
-    // __first points to first false, everything prior to __first is already set.
-    // Either prove [__first, __last) is all false and return __first, or point __last to last true
-    do
-    {
-        if (__first == --__last)
-            return __first;
-    } while (!__pred(*__last));
-    // We now have a reduced range [__first, __last]
-    // *__first is known to be false
-    // *__last is known to be true
-    // __len >= 2
-    difference_type __len = _VSTD::distance(__first, __last) + 1;
-    pair<value_type*, ptrdiff_t> __p(0, 0);
-    unique_ptr<value_type, __return_temporary_buffer> __h;
-    if (__len >= __alloc_limit)
-    {
-        __p = _VSTD::get_temporary_buffer<value_type>(__len);
-        __h.reset(__p.first);
-    }
-    return __stable_partition<typename add_lvalue_reference<_Predicate>::type>
-                             (__first, __last, __pred, __len, __p, bidirectional_iterator_tag());
-}
-
-template <class _ForwardIterator, class _Predicate>
-inline _LIBCPP_INLINE_VISIBILITY
-_ForwardIterator
-stable_partition(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred)
-{
-    return __stable_partition<typename add_lvalue_reference<_Predicate>::type>
-                             (__first, __last, __pred, typename iterator_traits<_ForwardIterator>::iterator_category());
-}
-
-// is_sorted_until
-
-template <class _ForwardIterator, class _Compare>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
-is_sorted_until(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp)
-{
-    if (__first != __last)
-    {
-        _ForwardIterator __i = __first;
-        while (++__i != __last)
-        {
-            if (__comp(*__i, *__first))
-                return __i;
-            __first = __i;
-        }
-    }
-    return __last;
-}
-
-template<class _ForwardIterator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_ForwardIterator
-is_sorted_until(_ForwardIterator __first, _ForwardIterator __last)
-{
-    return _VSTD::is_sorted_until(__first, __last, __less<typename iterator_traits<_ForwardIterator>::value_type>());
-}
-
-// is_sorted
-
-template <class _ForwardIterator, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-is_sorted(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp)
-{
-    return _VSTD::is_sorted_until(__first, __last, __comp) == __last;
-}
-
-template<class _ForwardIterator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-is_sorted(_ForwardIterator __first, _ForwardIterator __last)
-{
-    return _VSTD::is_sorted(__first, __last, __less<typename iterator_traits<_ForwardIterator>::value_type>());
-}
-
-// sort
-
-// stable, 2-3 compares, 0-2 swaps
-
-template <class _Compare, class _ForwardIterator>
-unsigned
-__sort3(_ForwardIterator __x, _ForwardIterator __y, _ForwardIterator __z, _Compare __c)
-{
-    unsigned __r = 0;
-    if (!__c(*__y, *__x))          // if x <= y
-    {
-        if (!__c(*__z, *__y))      // if y <= z
-            return __r;            // x <= y && y <= z
-                                   // x <= y && y > z
-        swap(*__y, *__z);          // x <= z && y < z
-        __r = 1;
-        if (__c(*__y, *__x))       // if x > y
-        {
-            swap(*__x, *__y);      // x < y && y <= z
-            __r = 2;
-        }
-        return __r;                // x <= y && y < z
-    }
-    if (__c(*__z, *__y))           // x > y, if y > z
-    {
-        swap(*__x, *__z);          // x < y && y < z
-        __r = 1;
-        return __r;
-    }
-    swap(*__x, *__y);              // x > y && y <= z
-    __r = 1;                       // x < y && x <= z
-    if (__c(*__z, *__y))           // if y > z
-    {
-        swap(*__y, *__z);          // x <= y && y < z
-        __r = 2;
-    }
-    return __r;
-}                                  // x <= y && y <= z
-
-// stable, 3-6 compares, 0-5 swaps
-
-template <class _Compare, class _ForwardIterator>
-unsigned
-__sort4(_ForwardIterator __x1, _ForwardIterator __x2, _ForwardIterator __x3,
-            _ForwardIterator __x4, _Compare __c)
-{
-    unsigned __r = __sort3<_Compare>(__x1, __x2, __x3, __c);
-    if (__c(*__x4, *__x3))
-    {
-        swap(*__x3, *__x4);
-        ++__r;
-        if (__c(*__x3, *__x2))
-        {
-            swap(*__x2, *__x3);
-            ++__r;
-            if (__c(*__x2, *__x1))
-            {
-                swap(*__x1, *__x2);
-                ++__r;
-            }
-        }
-    }
-    return __r;
-}
-
-// stable, 4-10 compares, 0-9 swaps
-
-template <class _Compare, class _ForwardIterator>
-_LIBCPP_HIDDEN
-unsigned
-__sort5(_ForwardIterator __x1, _ForwardIterator __x2, _ForwardIterator __x3,
-            _ForwardIterator __x4, _ForwardIterator __x5, _Compare __c)
-{
-    unsigned __r = __sort4<_Compare>(__x1, __x2, __x3, __x4, __c);
-    if (__c(*__x5, *__x4))
-    {
-        swap(*__x4, *__x5);
-        ++__r;
-        if (__c(*__x4, *__x3))
-        {
-            swap(*__x3, *__x4);
-            ++__r;
-            if (__c(*__x3, *__x2))
-            {
-                swap(*__x2, *__x3);
-                ++__r;
-                if (__c(*__x2, *__x1))
-                {
-                    swap(*__x1, *__x2);
-                    ++__r;
-                }
-            }
-        }
-    }
-    return __r;
-}
-
-// Assumes size > 0
-template <class _Compare, class _BirdirectionalIterator>
-void
-__selection_sort(_BirdirectionalIterator __first, _BirdirectionalIterator __last, _Compare __comp)
-{
-    _BirdirectionalIterator __lm1 = __last;
-    for (--__lm1; __first != __lm1; ++__first)
-    {
-        _BirdirectionalIterator __i = _VSTD::min_element<_BirdirectionalIterator,
-                                                        typename add_lvalue_reference<_Compare>::type>
-                                                       (__first, __last, __comp);
-        if (__i != __first)
-            swap(*__first, *__i);
-    }
-}
-
-template <class _Compare, class _BirdirectionalIterator>
-void
-__insertion_sort(_BirdirectionalIterator __first, _BirdirectionalIterator __last, _Compare __comp)
-{
-    typedef typename iterator_traits<_BirdirectionalIterator>::value_type value_type;
-    if (__first != __last)
-    {
-        _BirdirectionalIterator __i = __first;
-        for (++__i; __i != __last; ++__i)
-        {
-            _BirdirectionalIterator __j = __i;
-            value_type __t(_VSTD::move(*__j));
-            for (_BirdirectionalIterator __k = __i; __k != __first && __comp(__t,  *--__k); --__j)
-                *__j = _VSTD::move(*__k);
-            *__j = _VSTD::move(__t);
-        }
-    }
-}
-
-template <class _Compare, class _RandomAccessIterator>
-void
-__insertion_sort_3(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
-{
-    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
-    _RandomAccessIterator __j = __first+2;
-    __sort3<_Compare>(__first, __first+1, __j, __comp);
-    for (_RandomAccessIterator __i = __j+1; __i != __last; ++__i)
-    {
-        if (__comp(*__i, *__j))
-        {
-            value_type __t(_VSTD::move(*__i));
-            _RandomAccessIterator __k = __j;
-            __j = __i;
-            do
-            {
-                *__j = _VSTD::move(*__k);
-                __j = __k;
-            } while (__j != __first && __comp(__t, *--__k));
-            *__j = _VSTD::move(__t);
-        }
-        __j = __i;
-    }
-}
-
-template <class _Compare, class _RandomAccessIterator>
-bool
-__insertion_sort_incomplete(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
-{
-    switch (__last - __first)
-    {
-    case 0:
-    case 1:
-        return true;
-    case 2:
-        if (__comp(*--__last, *__first))
-            swap(*__first, *__last);
-        return true;
-    case 3:
-        _VSTD::__sort3<_Compare>(__first, __first+1, --__last, __comp);
-        return true;
-    case 4:
-        _VSTD::__sort4<_Compare>(__first, __first+1, __first+2, --__last, __comp);
-        return true;
-    case 5:
-        _VSTD::__sort5<_Compare>(__first, __first+1, __first+2, __first+3, --__last, __comp);
-        return true;
-    }
-    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
-    _RandomAccessIterator __j = __first+2;
-    __sort3<_Compare>(__first, __first+1, __j, __comp);
-    const unsigned __limit = 8;
-    unsigned __count = 0;
-    for (_RandomAccessIterator __i = __j+1; __i != __last; ++__i)
-    {
-        if (__comp(*__i, *__j))
-        {
-            value_type __t(_VSTD::move(*__i));
-            _RandomAccessIterator __k = __j;
-            __j = __i;
-            do
-            {
-                *__j = _VSTD::move(*__k);
-                __j = __k;
-            } while (__j != __first && __comp(__t, *--__k));
-            *__j = _VSTD::move(__t);
-            if (++__count == __limit)
-                return ++__i == __last;
-        }
-        __j = __i;
-    }
-    return true;
-}
-
-template <class _Compare, class _BirdirectionalIterator>
-void
-__insertion_sort_move(_BirdirectionalIterator __first1, _BirdirectionalIterator __last1,
-                      typename iterator_traits<_BirdirectionalIterator>::value_type* __first2, _Compare __comp)
-{
-    typedef typename iterator_traits<_BirdirectionalIterator>::value_type value_type;
-    if (__first1 != __last1)
-    {
-        __destruct_n __d(0);
-        unique_ptr<value_type, __destruct_n&> __h(__first2, __d);
-        value_type* __last2 = __first2;
-        ::new(__last2) value_type(_VSTD::move(*__first1));
-        __d.__incr((value_type*)0);
-        for (++__last2; ++__first1 != __last1; ++__last2)
-        {
-            value_type* __j2 = __last2;
-            value_type* __i2 = __j2;
-            if (__comp(*__first1, *--__i2))
-            {
-                ::new(__j2) value_type(_VSTD::move(*__i2));
-                __d.__incr((value_type*)0);
-                for (--__j2; __i2 != __first2 && __comp(*__first1,  *--__i2); --__j2)
-                    *__j2 = _VSTD::move(*__i2);
-                *__j2 = _VSTD::move(*__first1);
-            }
-            else
-            {
-                ::new(__j2) value_type(_VSTD::move(*__first1));
-                __d.__incr((value_type*)0);
-            }
-        }
-        __h.release();
-    }
-}
-
-template <class _Compare, class _RandomAccessIterator>
-void
-__sort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
-{
-    // _Compare is known to be a reference type
-    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
-    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
-    const difference_type __limit = is_trivially_copy_constructible<value_type>::value &&
-                                    is_trivially_copy_assignable<value_type>::value ? 30 : 6;
-    while (true)
-    {
-    __restart:
-        difference_type __len = __last - __first;
-        switch (__len)
-        {
-        case 0:
-        case 1:
-            return;
-        case 2:
-            if (__comp(*--__last, *__first))
-                swap(*__first, *__last);
-            return;
-        case 3:
-            _VSTD::__sort3<_Compare>(__first, __first+1, --__last, __comp);
-            return;
-        case 4:
-            _VSTD::__sort4<_Compare>(__first, __first+1, __first+2, --__last, __comp);
-            return;
-        case 5:
-            _VSTD::__sort5<_Compare>(__first, __first+1, __first+2, __first+3, --__last, __comp);
-            return;
-        }
-        if (__len <= __limit)
-        {
-            _VSTD::__insertion_sort_3<_Compare>(__first, __last, __comp);
-            return;
-        }
-        // __len > 5
-        _RandomAccessIterator __m = __first;
-        _RandomAccessIterator __lm1 = __last;
-        --__lm1;
-        unsigned __n_swaps;
-        {
-        difference_type __delta;
-        if (__len >= 1000)
-        {
-            __delta = __len/2;
-            __m += __delta;
-            __delta /= 2;
-            __n_swaps = _VSTD::__sort5<_Compare>(__first, __first + __delta, __m, __m+__delta, __lm1, __comp);
-        }
-        else
-        {
-            __delta = __len/2;
-            __m += __delta;
-            __n_swaps = _VSTD::__sort3<_Compare>(__first, __m, __lm1, __comp);
-        }
-        }
-        // *__m is median
-        // partition [__first, __m) < *__m and *__m <= [__m, __last)
-        // (this inhibits tossing elements equivalent to __m around unnecessarily)
-        _RandomAccessIterator __i = __first;
-        _RandomAccessIterator __j = __lm1;
-        // j points beyond range to be tested, *__m is known to be <= *__lm1
-        // The search going up is known to be guarded but the search coming down isn't.
-        // Prime the downward search with a guard.
-        if (!__comp(*__i, *__m))  // if *__first == *__m
-        {
-            // *__first == *__m, *__first doesn't go in first part
-            // manually guard downward moving __j against __i
-            while (true)
-            {
-                if (__i == --__j)
-                {
-                    // *__first == *__m, *__m <= all other elements
-                    // Parition instead into [__first, __i) == *__first and *__first < [__i, __last)
-                    ++__i;  // __first + 1
-                    __j = __last;
-                    if (!__comp(*__first, *--__j))  // we need a guard if *__first == *(__last-1)
-                    {
-                        while (true)
-                        {
-                            if (__i == __j)
-                                return;  // [__first, __last) all equivalent elements
-                            if (__comp(*__first, *__i))
-                            {
-                                swap(*__i, *__j);
-                                ++__n_swaps;
-                                ++__i;
-                                break;
-                            }
-                            ++__i;
-                        }
-                    }
-                    // [__first, __i) == *__first and *__first < [__j, __last) and __j == __last - 1
-                    if (__i == __j)
-                        return;
-                    while (true)
-                    {
-                        while (!__comp(*__first, *__i))
-                            ++__i;
-                        while (__comp(*__first, *--__j))
-                            ;
-                        if (__i >= __j)
-                            break;
-                        swap(*__i, *__j);
-                        ++__n_swaps;
-                        ++__i;
-                    }
-                    // [__first, __i) == *__first and *__first < [__i, __last)
-                    // The first part is sorted, sort the secod part
-                    // _VSTD::__sort<_Compare>(__i, __last, __comp);
-                    __first = __i;
-                    goto __restart;
-                }
-                if (__comp(*__j, *__m))
-                {
-                    swap(*__i, *__j);
-                    ++__n_swaps;
-                    break;  // found guard for downward moving __j, now use unguarded partition
-                }
-            }
-        }
-        // It is known that *__i < *__m
-        ++__i;
-        // j points beyond range to be tested, *__m is known to be <= *__lm1
-        // if not yet partitioned...
-        if (__i < __j)
-        {
-            // known that *(__i - 1) < *__m
-            // known that __i <= __m
-            while (true)
-            {
-                // __m still guards upward moving __i
-                while (__comp(*__i, *__m))
-                    ++__i;
-                // It is now known that a guard exists for downward moving __j
-                while (!__comp(*--__j, *__m))
-                    ;
-                if (__i > __j)
-                    break;
-                swap(*__i, *__j);
-                ++__n_swaps;
-                // It is known that __m != __j
-                // If __m just moved, follow it
-                if (__m == __i)
-                    __m = __j;
-                ++__i;
-            }
-        }
-        // [__first, __i) < *__m and *__m <= [__i, __last)
-        if (__i != __m && __comp(*__m, *__i))
-        {
-            swap(*__i, *__m);
-            ++__n_swaps;
-        }
-        // [__first, __i) < *__i and *__i <= [__i+1, __last)
-        // If we were given a perfect partition, see if insertion sort is quick...
-        if (__n_swaps == 0)
-        {
-            bool __fs = _VSTD::__insertion_sort_incomplete<_Compare>(__first, __i, __comp);
-            if (_VSTD::__insertion_sort_incomplete<_Compare>(__i+1, __last, __comp))
-            {
-                if (__fs)
-                    return;
-                __last = __i;
-                continue;
-            }
-            else
-            {
-                if (__fs)
-                {
-                    __first = ++__i;
-                    continue;
-                }
-            }
-        }
-        // sort smaller range with recursive call and larger with tail recursion elimination
-        if (__i - __first < __last - __i)
-        {
-            _VSTD::__sort<_Compare>(__first, __i, __comp);
-            // _VSTD::__sort<_Compare>(__i+1, __last, __comp);
-            __first = ++__i;
-        }
-        else
-        {
-            _VSTD::__sort<_Compare>(__i+1, __last, __comp);
-            // _VSTD::__sort<_Compare>(__first, __i, __comp);
-            __last = __i;
-        }
-    }
-}
-
-// This forwarder keeps the top call and the recursive calls using the same instantiation, forcing a reference _Compare
-template <class _RandomAccessIterator, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-sort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
-{
-#ifdef _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
-    __debug_less<_Compare> __c(__comp);
-    __sort<_Comp_ref>(__first, __last, __c);
-#else  // _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
-    __sort<_Comp_ref>(__first, __last, __comp);
-#endif  // _LIBCPP_DEBUG
-}
-
-template <class _RandomAccessIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-sort(_RandomAccessIterator __first, _RandomAccessIterator __last)
-{
-    _VSTD::sort(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-sort(_Tp** __first, _Tp** __last)
-{
-    _VSTD::sort((size_t*)__first, (size_t*)__last, __less<size_t>());
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-sort(__wrap_iter<_Tp*> __first, __wrap_iter<_Tp*> __last)
-{
-    _VSTD::sort(__first.base(), __last.base());
-}
-
-template <class _Tp, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-sort(__wrap_iter<_Tp*> __first, __wrap_iter<_Tp*> __last, _Compare __comp)
-{
-    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
-    _VSTD::sort<_Tp*, _Comp_ref>(__first.base(), __last.base(), __comp);
-}
-
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<char>&, char*>(char*, char*, __less<char>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<wchar_t>&, wchar_t*>(wchar_t*, wchar_t*, __less<wchar_t>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<signed char>&, signed char*>(signed char*, signed char*, __less<signed char>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<unsigned char>&, unsigned char*>(unsigned char*, unsigned char*, __less<unsigned char>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<short>&, short*>(short*, short*, __less<short>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<unsigned short>&, unsigned short*>(unsigned short*, unsigned short*, __less<unsigned short>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<int>&, int*>(int*, int*, __less<int>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<unsigned>&, unsigned*>(unsigned*, unsigned*, __less<unsigned>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<long>&, long*>(long*, long*, __less<long>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<unsigned long>&, unsigned long*>(unsigned long*, unsigned long*, __less<unsigned long>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<long long>&, long long*>(long long*, long long*, __less<long long>&))
-_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>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<float>&, float*>(float*, float*, __less<float>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<double>&, double*>(double*, double*, __less<double>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<long double>&, long double*>(long double*, long double*, __less<long double>&))
-
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<char>&, char*>(char*, char*, __less<char>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<wchar_t>&, wchar_t*>(wchar_t*, wchar_t*, __less<wchar_t>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<signed char>&, signed char*>(signed char*, signed char*, __less<signed char>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<unsigned char>&, unsigned char*>(unsigned char*, unsigned char*, __less<unsigned char>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<short>&, short*>(short*, short*, __less<short>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<unsigned short>&, unsigned short*>(unsigned short*, unsigned short*, __less<unsigned short>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<int>&, int*>(int*, int*, __less<int>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<unsigned>&, unsigned*>(unsigned*, unsigned*, __less<unsigned>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<long>&, long*>(long*, long*, __less<long>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<unsigned long>&, unsigned long*>(unsigned long*, unsigned long*, __less<unsigned long>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<long long>&, long long*>(long long*, long long*, __less<long long>&))
-_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>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<float>&, float*>(float*, float*, __less<float>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<double>&, double*>(double*, double*, __less<double>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<long double>&, long double*>(long double*, long double*, __less<long double>&))
-
-_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>&))
-
-// lower_bound
-
-template <class _Compare, class _ForwardIterator, class _Tp>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
-__lower_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
-{
-    typedef typename iterator_traits<_ForwardIterator>::difference_type difference_type;
-    difference_type __len = _VSTD::distance(__first, __last);
-    while (__len != 0)
-    {
-        difference_type __l2 = _VSTD::__half_positive(__len);
-        _ForwardIterator __m = __first;
-        _VSTD::advance(__m, __l2);
-        if (__comp(*__m, __value_))
-        {
-            __first = ++__m;
-            __len -= __l2 + 1;
-        }
-        else
-            __len = __l2;
-    }
-    return __first;
-}
-
-template <class _ForwardIterator, class _Tp, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_ForwardIterator
-lower_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
-{
-    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
-    return __lower_bound<_Comp_ref>(__first, __last, __value_, __comp);
-}
-
-template <class _ForwardIterator, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_ForwardIterator
-lower_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_)
-{
-    return _VSTD::lower_bound(__first, __last, __value_,
-                             __less<typename iterator_traits<_ForwardIterator>::value_type, _Tp>());
-}
-
-// upper_bound
-
-template <class _Compare, class _ForwardIterator, class _Tp>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
-__upper_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
-{
-    typedef typename iterator_traits<_ForwardIterator>::difference_type difference_type;
-    difference_type __len = _VSTD::distance(__first, __last);
-    while (__len != 0)
-    {
-        difference_type __l2 = _VSTD::__half_positive(__len);
-        _ForwardIterator __m = __first;
-        _VSTD::advance(__m, __l2);
-        if (__comp(__value_, *__m))
-            __len = __l2;
-        else
-        {
-            __first = ++__m;
-            __len -= __l2 + 1;
-        }
-    }
-    return __first;
-}
-
-template <class _ForwardIterator, class _Tp, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_ForwardIterator
-upper_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
-{
-    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
-    return __upper_bound<_Comp_ref>(__first, __last, __value_, __comp);
-}
-
-template <class _ForwardIterator, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_ForwardIterator
-upper_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_)
-{
-    return _VSTD::upper_bound(__first, __last, __value_,
-                             __less<_Tp, typename iterator_traits<_ForwardIterator>::value_type>());
-}
-
-// equal_range
-
-template <class _Compare, class _ForwardIterator, class _Tp>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 pair<_ForwardIterator, _ForwardIterator>
-__equal_range(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
-{
-    typedef typename iterator_traits<_ForwardIterator>::difference_type difference_type;
-    difference_type __len = _VSTD::distance(__first, __last);
-    while (__len != 0)
-    {
-        difference_type __l2 = _VSTD::__half_positive(__len);
-        _ForwardIterator __m = __first;
-        _VSTD::advance(__m, __l2);
-        if (__comp(*__m, __value_))
-        {
-            __first = ++__m;
-            __len -= __l2 + 1;
-        }
-        else if (__comp(__value_, *__m))
-        {
-            __last = __m;
-            __len = __l2;
-        }
-        else
-        {
-            _ForwardIterator __mp1 = __m;
-            return pair<_ForwardIterator, _ForwardIterator>
-                   (
-                      __lower_bound<_Compare>(__first, __m, __value_, __comp),
-                      __upper_bound<_Compare>(++__mp1, __last, __value_, __comp)
-                   );
-        }
-    }
-    return pair<_ForwardIterator, _ForwardIterator>(__first, __first);
-}
-
-template <class _ForwardIterator, class _Tp, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-pair<_ForwardIterator, _ForwardIterator>
-equal_range(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
-{
-#ifdef _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
-    __debug_less<_Compare> __c(__comp);
-    return __equal_range<_Comp_ref>(__first, __last, __value_, __c);
-#else  // _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
-    return __equal_range<_Comp_ref>(__first, __last, __value_, __comp);
-#endif  // _LIBCPP_DEBUG
-}
-
-template <class _ForwardIterator, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-pair<_ForwardIterator, _ForwardIterator>
-equal_range(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_)
-{
-    return _VSTD::equal_range(__first, __last, __value_,
-                             __less<typename iterator_traits<_ForwardIterator>::value_type, _Tp>());
-}
-
-// binary_search
-
-template <class _Compare, class _ForwardIterator, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-__binary_search(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
-{
-    __first = __lower_bound<_Compare>(__first, __last, __value_, __comp);
-    return __first != __last && !__comp(__value_, *__first);
-}
-
-template <class _ForwardIterator, class _Tp, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-binary_search(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
-{
-#ifdef _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
-    __debug_less<_Compare> __c(__comp);
-    return __binary_search<_Comp_ref>(__first, __last, __value_, __c);
-#else  // _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
-    return __binary_search<_Comp_ref>(__first, __last, __value_, __comp);
-#endif  // _LIBCPP_DEBUG
-}
-
-template <class _ForwardIterator, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-binary_search(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_)
-{
-    return _VSTD::binary_search(__first, __last, __value_,
-                             __less<typename iterator_traits<_ForwardIterator>::value_type, _Tp>());
-}
-
-// merge
-
-template <class _Compare, class _InputIterator1, class _InputIterator2, class _OutputIterator>
-_OutputIterator
-__merge(_InputIterator1 __first1, _InputIterator1 __last1,
-        _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
-{
-    for (; __first1 != __last1; ++__result)
-    {
-        if (__first2 == __last2)
-            return _VSTD::copy(__first1, __last1, __result);
-        if (__comp(*__first2, *__first1))
-        {
-            *__result = *__first2;
-            ++__first2;
-        }
-        else
-        {
-            *__result = *__first1;
-            ++__first1;
-        }
-    }
-    return _VSTD::copy(__first2, __last2, __result);
-}
-
-template <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY
-_OutputIterator
-merge(_InputIterator1 __first1, _InputIterator1 __last1,
-      _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
-{
-#ifdef _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
-    __debug_less<_Compare> __c(__comp);
-    return _VSTD::__merge<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __c);
-#else  // _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
-    return _VSTD::__merge<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __comp);
-#endif  // _LIBCPP_DEBUG
-}
-
-template <class _InputIterator1, class _InputIterator2, class _OutputIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-_OutputIterator
-merge(_InputIterator1 __first1, _InputIterator1 __last1,
-      _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result)
-{
-    typedef typename iterator_traits<_InputIterator1>::value_type __v1;
-    typedef typename iterator_traits<_InputIterator2>::value_type __v2;
-    return merge(__first1, __last1, __first2, __last2, __result, __less<__v1, __v2>());
-}
-
-// inplace_merge
-
-template <class _Compare, class _InputIterator1, class _InputIterator2,
-          class _OutputIterator>
-void __half_inplace_merge(_InputIterator1 __first1, _InputIterator1 __last1,
-                          _InputIterator2 __first2, _InputIterator2 __last2,
-                          _OutputIterator __result, _Compare __comp)
-{
-    for (; __first1 != __last1; ++__result)
-    {
-        if (__first2 == __last2)
-        {
-            _VSTD::move(__first1, __last1, __result);
-            return;
-        }
-
-        if (__comp(*__first2, *__first1))
-        {
-            *__result = _VSTD::move(*__first2);
-            ++__first2;
-        }
-        else
-        {
-            *__result = _VSTD::move(*__first1);
-            ++__first1;
-        }
-    }
-    // __first2 through __last2 are already in the right spot.
-}
-
-template <class _Compare, class _BidirectionalIterator>
-void
-__buffered_inplace_merge(_BidirectionalIterator __first, _BidirectionalIterator __middle, _BidirectionalIterator __last,
-                _Compare __comp, typename iterator_traits<_BidirectionalIterator>::difference_type __len1,
-                                 typename iterator_traits<_BidirectionalIterator>::difference_type __len2,
-                typename iterator_traits<_BidirectionalIterator>::value_type* __buff)
-{
-    typedef typename iterator_traits<_BidirectionalIterator>::value_type value_type;
-    __destruct_n __d(0);
-    unique_ptr<value_type, __destruct_n&> __h2(__buff, __d);
-    if (__len1 <= __len2)
-    {
-        value_type* __p = __buff;
-        for (_BidirectionalIterator __i = __first; __i != __middle; __d.__incr((value_type*)0), (void) ++__i, ++__p)
-            ::new(__p) value_type(_VSTD::move(*__i));
-        __half_inplace_merge(__buff, __p, __middle, __last, __first, __comp);
-    }
-    else
-    {
-        value_type* __p = __buff;
-        for (_BidirectionalIterator __i = __middle; __i != __last; __d.__incr((value_type*)0), (void) ++__i, ++__p)
-            ::new(__p) value_type(_VSTD::move(*__i));
-        typedef reverse_iterator<_BidirectionalIterator> _RBi;
-        typedef reverse_iterator<value_type*> _Rv;
-        __half_inplace_merge(_Rv(__p), _Rv(__buff),
-                             _RBi(__middle), _RBi(__first),
-                             _RBi(__last), __invert<_Compare>(__comp));
-    }
-}
-
-template <class _Compare, class _BidirectionalIterator>
-void
-__inplace_merge(_BidirectionalIterator __first, _BidirectionalIterator __middle, _BidirectionalIterator __last,
-                _Compare __comp, typename iterator_traits<_BidirectionalIterator>::difference_type __len1,
-                                 typename iterator_traits<_BidirectionalIterator>::difference_type __len2,
-                typename iterator_traits<_BidirectionalIterator>::value_type* __buff, ptrdiff_t __buff_size)
-{
-    typedef typename iterator_traits<_BidirectionalIterator>::difference_type difference_type;
-    while (true)
-    {
-        // if __middle == __last, we're done
-        if (__len2 == 0)
-            return;
-        if (__len1 <= __buff_size || __len2 <= __buff_size)
-            return __buffered_inplace_merge<_Compare>
-                   (__first, __middle, __last, __comp, __len1, __len2, __buff);
-        // shrink [__first, __middle) as much as possible (with no moves), returning if it shrinks to 0
-        for (; true; ++__first, (void) --__len1)
-        {
-            if (__len1 == 0)
-                return;
-            if (__comp(*__middle, *__first))
-                break;
-        }
-        // __first < __middle < __last
-        // *__first > *__middle
-        // partition [__first, __m1) [__m1, __middle) [__middle, __m2) [__m2, __last) such that
-        //     all elements in:
-        //         [__first, __m1)  <= [__middle, __m2)
-        //         [__middle, __m2) <  [__m1, __middle)
-        //         [__m1, __middle) <= [__m2, __last)
-        //     and __m1 or __m2 is in the middle of its range
-        _BidirectionalIterator __m1;  // "median" of [__first, __middle)
-        _BidirectionalIterator __m2;  // "median" of [__middle, __last)
-        difference_type __len11;      // distance(__first, __m1)
-        difference_type __len21;      // distance(__middle, __m2)
-        // binary search smaller range
-        if (__len1 < __len2)
-        {   // __len >= 1, __len2 >= 2
-            __len21 = __len2 / 2;
-            __m2 = __middle;
-            _VSTD::advance(__m2, __len21);
-            __m1 = __upper_bound<_Compare>(__first, __middle, *__m2, __comp);
-            __len11 = _VSTD::distance(__first, __m1);
-        }
-        else
-        {
-            if (__len1 == 1)
-            {   // __len1 >= __len2 && __len2 > 0, therefore __len2 == 1
-                // It is known *__first > *__middle
-                swap(*__first, *__middle);
-                return;
-            }
-            // __len1 >= 2, __len2 >= 1
-            __len11 = __len1 / 2;
-            __m1 = __first;
-            _VSTD::advance(__m1, __len11);
-            __m2 = __lower_bound<_Compare>(__middle, __last, *__m1, __comp);
-            __len21 = _VSTD::distance(__middle, __m2);
-        }
-        difference_type __len12 = __len1 - __len11;  // distance(__m1, __middle)
-        difference_type __len22 = __len2 - __len21;  // distance(__m2, __last)
-        // [__first, __m1) [__m1, __middle) [__middle, __m2) [__m2, __last)
-        // swap middle two partitions
-        __middle = _VSTD::rotate(__m1, __middle, __m2);
-        // __len12 and __len21 now have swapped meanings
-        // merge smaller range with recurisve call and larger with tail recursion elimination
-        if (__len11 + __len21 < __len12 + __len22)
-        {
-            __inplace_merge<_Compare>(__first, __m1, __middle, __comp, __len11, __len21, __buff, __buff_size);
-//          __inplace_merge<_Compare>(__middle, __m2, __last, __comp, __len12, __len22, __buff, __buff_size);
-            __first = __middle;
-            __middle = __m2;
-            __len1 = __len12;
-            __len2 = __len22;
-        }
-        else
-        {
-            __inplace_merge<_Compare>(__middle, __m2, __last, __comp, __len12, __len22, __buff, __buff_size);
-//          __inplace_merge<_Compare>(__first, __m1, __middle, __comp, __len11, __len21, __buff, __buff_size);
-            __last = __middle;
-            __middle = __m1;
-            __len1 = __len11;
-            __len2 = __len21;
-        }
-    }
-}
-
-template <class _BidirectionalIterator, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-inplace_merge(_BidirectionalIterator __first, _BidirectionalIterator __middle, _BidirectionalIterator __last,
-              _Compare __comp)
-{
-    typedef typename iterator_traits<_BidirectionalIterator>::value_type value_type;
-    typedef typename iterator_traits<_BidirectionalIterator>::difference_type difference_type;
-    difference_type __len1 = _VSTD::distance(__first, __middle);
-    difference_type __len2 = _VSTD::distance(__middle, __last);
-    difference_type __buf_size = _VSTD::min(__len1, __len2);
-    pair<value_type*, ptrdiff_t> __buf = _VSTD::get_temporary_buffer<value_type>(__buf_size);
-    unique_ptr<value_type, __return_temporary_buffer> __h(__buf.first);
-
-#ifdef _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
-    __debug_less<_Compare> __c(__comp);
-    return _VSTD::__inplace_merge<_Comp_ref>(__first, __middle, __last, __c, __len1, __len2,
-                                            __buf.first, __buf.second);
-#else  // _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
-    return _VSTD::__inplace_merge<_Comp_ref>(__first, __middle, __last, __comp, __len1, __len2,
-                                            __buf.first, __buf.second);
-#endif  // _LIBCPP_DEBUG
-}
-
-template <class _BidirectionalIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-inplace_merge(_BidirectionalIterator __first, _BidirectionalIterator __middle, _BidirectionalIterator __last)
-{
-    _VSTD::inplace_merge(__first, __middle, __last,
-                        __less<typename iterator_traits<_BidirectionalIterator>::value_type>());
-}
-
-// stable_sort
-
-template <class _Compare, class _InputIterator1, class _InputIterator2>
-void
-__merge_move_construct(_InputIterator1 __first1, _InputIterator1 __last1,
-        _InputIterator2 __first2, _InputIterator2 __last2,
-        typename iterator_traits<_InputIterator1>::value_type* __result, _Compare __comp)
-{
-    typedef typename iterator_traits<_InputIterator1>::value_type value_type;
-    __destruct_n __d(0);
-    unique_ptr<value_type, __destruct_n&> __h(__result, __d);
-    for (; true; ++__result)
-    {
-        if (__first1 == __last1)
-        {
-            for (; __first2 != __last2; ++__first2, ++__result, __d.__incr((value_type*)0))
-                ::new (__result) value_type(_VSTD::move(*__first2));
-            __h.release();
-            return;
-        }
-        if (__first2 == __last2)
-        {
-            for (; __first1 != __last1; ++__first1, ++__result, __d.__incr((value_type*)0))
-                ::new (__result) value_type(_VSTD::move(*__first1));
-            __h.release();
-            return;
-        }
-        if (__comp(*__first2, *__first1))
-        {
-            ::new (__result) value_type(_VSTD::move(*__first2));
-            __d.__incr((value_type*)0);
-            ++__first2;
-        }
-        else
-        {
-            ::new (__result) value_type(_VSTD::move(*__first1));
-            __d.__incr((value_type*)0);
-            ++__first1;
-        }
-    }
-}
-
-template <class _Compare, class _InputIterator1, class _InputIterator2, class _OutputIterator>
-void
-__merge_move_assign(_InputIterator1 __first1, _InputIterator1 __last1,
-        _InputIterator2 __first2, _InputIterator2 __last2,
-        _OutputIterator __result, _Compare __comp)
-{
-    for (; __first1 != __last1; ++__result)
-    {
-        if (__first2 == __last2)
-        {
-            for (; __first1 != __last1; ++__first1, ++__result)
-                *__result = _VSTD::move(*__first1);
-            return;
-        }
-        if (__comp(*__first2, *__first1))
-        {
-            *__result = _VSTD::move(*__first2);
-            ++__first2;
-        }
-        else
-        {
-            *__result = _VSTD::move(*__first1);
-            ++__first1;
-        }
-    }
-    for (; __first2 != __last2; ++__first2, ++__result)
-        *__result = _VSTD::move(*__first2);
-}
-
-template <class _Compare, class _RandomAccessIterator>
-void
-__stable_sort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp,
-              typename iterator_traits<_RandomAccessIterator>::difference_type __len,
-              typename iterator_traits<_RandomAccessIterator>::value_type* __buff, ptrdiff_t __buff_size);
-
-template <class _Compare, class _RandomAccessIterator>
-void
-__stable_sort_move(_RandomAccessIterator __first1, _RandomAccessIterator __last1, _Compare __comp,
-                   typename iterator_traits<_RandomAccessIterator>::difference_type __len,
-                   typename iterator_traits<_RandomAccessIterator>::value_type* __first2)
-{
-    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
-    switch (__len)
-    {
-    case 0:
-        return;
-    case 1:
-        ::new(__first2) value_type(_VSTD::move(*__first1));
-        return;
-    case 2:
-        __destruct_n __d(0);
-        unique_ptr<value_type, __destruct_n&> __h2(__first2, __d);
-        if (__comp(*--__last1, *__first1))
-        {
-            ::new(__first2) value_type(_VSTD::move(*__last1));
-            __d.__incr((value_type*)0);
-            ++__first2;
-            ::new(__first2) value_type(_VSTD::move(*__first1));
-        }
-        else
-        {
-            ::new(__first2) value_type(_VSTD::move(*__first1));
-            __d.__incr((value_type*)0);
-            ++__first2;
-            ::new(__first2) value_type(_VSTD::move(*__last1));
-        }
-        __h2.release();
-        return;
-    }
-    if (__len <= 8)
-    {
-        __insertion_sort_move<_Compare>(__first1, __last1, __first2, __comp);
-        return;
-    }
-    typename iterator_traits<_RandomAccessIterator>::difference_type __l2 = __len / 2;
-    _RandomAccessIterator __m = __first1 + __l2;
-    __stable_sort<_Compare>(__first1, __m, __comp, __l2, __first2, __l2);
-    __stable_sort<_Compare>(__m, __last1, __comp, __len - __l2, __first2 + __l2, __len - __l2);
-    __merge_move_construct<_Compare>(__first1, __m, __m, __last1, __first2, __comp);
-}
-
-template <class _Tp>
-struct __stable_sort_switch
-{
-    static const unsigned value = 128*is_trivially_copy_assignable<_Tp>::value;
-};
-
-template <class _Compare, class _RandomAccessIterator>
-void
-__stable_sort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp,
-              typename iterator_traits<_RandomAccessIterator>::difference_type __len,
-              typename iterator_traits<_RandomAccessIterator>::value_type* __buff, ptrdiff_t __buff_size)
-{
-    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
-    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
-    switch (__len)
-    {
-    case 0:
-    case 1:
-        return;
-    case 2:
-        if (__comp(*--__last, *__first))
-            swap(*__first, *__last);
-        return;
-    }
-    if (__len <= static_cast<difference_type>(__stable_sort_switch<value_type>::value))
-    {
-        __insertion_sort<_Compare>(__first, __last, __comp);
-        return;
-    }
-    typename iterator_traits<_RandomAccessIterator>::difference_type __l2 = __len / 2;
-    _RandomAccessIterator __m = __first + __l2;
-    if (__len <= __buff_size)
-    {
-        __destruct_n __d(0);
-        unique_ptr<value_type, __destruct_n&> __h2(__buff, __d);
-        __stable_sort_move<_Compare>(__first, __m, __comp, __l2, __buff);
-        __d.__set(__l2, (value_type*)0);
-        __stable_sort_move<_Compare>(__m, __last, __comp, __len - __l2, __buff + __l2);
-        __d.__set(__len, (value_type*)0);
-        __merge_move_assign<_Compare>(__buff, __buff + __l2, __buff + __l2, __buff + __len, __first, __comp);
-//         __merge<_Compare>(move_iterator<value_type*>(__buff),
-//                           move_iterator<value_type*>(__buff + __l2),
-//                           move_iterator<_RandomAccessIterator>(__buff + __l2),
-//                           move_iterator<_RandomAccessIterator>(__buff + __len),
-//                           __first, __comp);
-        return;
-    }
-    __stable_sort<_Compare>(__first, __m, __comp, __l2, __buff, __buff_size);
-    __stable_sort<_Compare>(__m, __last, __comp, __len - __l2, __buff, __buff_size);
-    __inplace_merge<_Compare>(__first, __m, __last, __comp, __l2, __len - __l2, __buff, __buff_size);
-}
-
-template <class _RandomAccessIterator, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-stable_sort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
-{
-    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
-    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
-    difference_type __len = __last - __first;
-    pair<value_type*, ptrdiff_t> __buf(0, 0);
-    unique_ptr<value_type, __return_temporary_buffer> __h;
-    if (__len > static_cast<difference_type>(__stable_sort_switch<value_type>::value))
-    {
-        __buf = _VSTD::get_temporary_buffer<value_type>(__len);
-        __h.reset(__buf.first);
-    }
-#ifdef _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
-    __debug_less<_Compare> __c(__comp);
-    __stable_sort<_Comp_ref>(__first, __last, __c, __len, __buf.first, __buf.second);
-#else  // _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
-    __stable_sort<_Comp_ref>(__first, __last, __comp, __len, __buf.first, __buf.second);
-#endif  // _LIBCPP_DEBUG
-}
-
-template <class _RandomAccessIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-stable_sort(_RandomAccessIterator __first, _RandomAccessIterator __last)
-{
-    _VSTD::stable_sort(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
-}
-
-// is_heap_until
-
-template <class _RandomAccessIterator, class _Compare>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 _RandomAccessIterator
-is_heap_until(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
-{
-    typedef typename _VSTD::iterator_traits<_RandomAccessIterator>::difference_type difference_type;
-    difference_type __len = __last - __first;
-    difference_type __p = 0;
-    difference_type __c = 1;
-    _RandomAccessIterator __pp = __first;
-    while (__c < __len)
-    {
-        _RandomAccessIterator __cp = __first + __c;
-        if (__comp(*__pp, *__cp))
-            return __cp;
-        ++__c;
-        ++__cp;
-        if (__c == __len)
-            return __last;
-        if (__comp(*__pp, *__cp))
-            return __cp;
-        ++__p;
-        ++__pp;
-        __c = 2 * __p + 1;
-    }
-    return __last;
-}
-
-template<class _RandomAccessIterator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_RandomAccessIterator
-is_heap_until(_RandomAccessIterator __first, _RandomAccessIterator __last)
-{
-    return _VSTD::is_heap_until(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
-}
-
-// is_heap
-
-template <class _RandomAccessIterator, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-is_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
-{
-    return _VSTD::is_heap_until(__first, __last, __comp) == __last;
-}
-
-template<class _RandomAccessIterator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-is_heap(_RandomAccessIterator __first, _RandomAccessIterator __last)
-{
-    return _VSTD::is_heap(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
-}
-
-// push_heap
-
-template <class _Compare, class _RandomAccessIterator>
-void
-__sift_up(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp,
-          typename iterator_traits<_RandomAccessIterator>::difference_type __len)
-{
-    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
-    if (__len > 1)
-    {
-        __len = (__len - 2) / 2;
-        _RandomAccessIterator __ptr = __first + __len;
-        if (__comp(*__ptr, *--__last))
-        {
-            value_type __t(_VSTD::move(*__last));
-            do
-            {
-                *__last = _VSTD::move(*__ptr);
-                __last = __ptr;
-                if (__len == 0)
-                    break;
-                __len = (__len - 1) / 2;
-                __ptr = __first + __len;
-            } while (__comp(*__ptr, __t));
-            *__last = _VSTD::move(__t);
-        }
-    }
-}
-
-template <class _RandomAccessIterator, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-push_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
-{
-#ifdef _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
-    __debug_less<_Compare> __c(__comp);
-    __sift_up<_Comp_ref>(__first, __last, __c, __last - __first);
-#else  // _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
-    __sift_up<_Comp_ref>(__first, __last, __comp, __last - __first);
-#endif  // _LIBCPP_DEBUG
-}
-
-template <class _RandomAccessIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-push_heap(_RandomAccessIterator __first, _RandomAccessIterator __last)
-{
-    _VSTD::push_heap(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
-}
-
-// pop_heap
-
-template <class _Compare, class _RandomAccessIterator>
-void
-__sift_down(_RandomAccessIterator __first, _RandomAccessIterator /*__last*/,
-            _Compare __comp,
-            typename iterator_traits<_RandomAccessIterator>::difference_type __len,
-            _RandomAccessIterator __start)
-{
-    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
-    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
-    // left-child of __start is at 2 * __start + 1
-    // right-child of __start is at 2 * __start + 2
-    difference_type __child = __start - __first;
-
-    if (__len < 2 || (__len - 2) / 2 < __child)
-        return;
-
-    __child = 2 * __child + 1;
-    _RandomAccessIterator __child_i = __first + __child;
-
-    if ((__child + 1) < __len && __comp(*__child_i, *(__child_i + 1))) {
-        // right-child exists and is greater than left-child
-        ++__child_i;
-        ++__child;
-    }
-
-    // check if we are in heap-order
-    if (__comp(*__child_i, *__start))
-        // we are, __start is larger than it's largest child
-        return;
-
-    value_type __top(_VSTD::move(*__start));
-    do
-    {
-        // we are not in heap-order, swap the parent with it's largest child
-        *__start = _VSTD::move(*__child_i);
-        __start = __child_i;
-
-        if ((__len - 2) / 2 < __child)
-            break;
-
-        // recompute the child based off of the updated parent
-        __child = 2 * __child + 1;
-        __child_i = __first + __child;
-
-        if ((__child + 1) < __len && __comp(*__child_i, *(__child_i + 1))) {
-            // right-child exists and is greater than left-child
-            ++__child_i;
-            ++__child;
-        }
-
-        // check if we are in heap-order
-    } while (!__comp(*__child_i, __top));
-    *__start = _VSTD::move(__top);
-}
-
-template <class _Compare, class _RandomAccessIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-__pop_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp,
-           typename iterator_traits<_RandomAccessIterator>::difference_type __len)
-{
-    if (__len > 1)
-    {
-        swap(*__first, *--__last);
-        __sift_down<_Compare>(__first, __last, __comp, __len - 1, __first);
-    }
-}
-
-template <class _RandomAccessIterator, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-pop_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
-{
-#ifdef _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
-    __debug_less<_Compare> __c(__comp);
-    __pop_heap<_Comp_ref>(__first, __last, __c, __last - __first);
-#else  // _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
-    __pop_heap<_Comp_ref>(__first, __last, __comp, __last - __first);
-#endif  // _LIBCPP_DEBUG
-}
-
-template <class _RandomAccessIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-pop_heap(_RandomAccessIterator __first, _RandomAccessIterator __last)
-{
-    _VSTD::pop_heap(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
-}
-
-// make_heap
-
-template <class _Compare, class _RandomAccessIterator>
-void
-__make_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
-{
-    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
-    difference_type __n = __last - __first;
-    if (__n > 1)
-    {
-        // start from the first parent, there is no need to consider children
-        for (difference_type __start = (__n - 2) / 2; __start >= 0; --__start)
-        {
-            __sift_down<_Compare>(__first, __last, __comp, __n, __first + __start);
-        }
-    }
-}
-
-template <class _RandomAccessIterator, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-make_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
-{
-#ifdef _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
-    __debug_less<_Compare> __c(__comp);
-    __make_heap<_Comp_ref>(__first, __last, __c);
-#else  // _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
-    __make_heap<_Comp_ref>(__first, __last, __comp);
-#endif  // _LIBCPP_DEBUG
-}
-
-template <class _RandomAccessIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-make_heap(_RandomAccessIterator __first, _RandomAccessIterator __last)
-{
-    _VSTD::make_heap(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
-}
-
-// sort_heap
-
-template <class _Compare, class _RandomAccessIterator>
-void
-__sort_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
-{
-    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
-    for (difference_type __n = __last - __first; __n > 1; --__last, --__n)
-        __pop_heap<_Compare>(__first, __last, __comp, __n);
-}
-
-template <class _RandomAccessIterator, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-sort_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
-{
-#ifdef _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
-    __debug_less<_Compare> __c(__comp);
-    __sort_heap<_Comp_ref>(__first, __last, __c);
-#else  // _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
-    __sort_heap<_Comp_ref>(__first, __last, __comp);
-#endif  // _LIBCPP_DEBUG
-}
-
-template <class _RandomAccessIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-sort_heap(_RandomAccessIterator __first, _RandomAccessIterator __last)
-{
-    _VSTD::sort_heap(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
-}
-
-// partial_sort
-
-template <class _Compare, class _RandomAccessIterator>
-void
-__partial_sort(_RandomAccessIterator __first, _RandomAccessIterator __middle, _RandomAccessIterator __last,
-             _Compare __comp)
-{
-    __make_heap<_Compare>(__first, __middle, __comp);
-    typename iterator_traits<_RandomAccessIterator>::difference_type __len = __middle - __first;
-    for (_RandomAccessIterator __i = __middle; __i != __last; ++__i)
-    {
-        if (__comp(*__i, *__first))
-        {
-            swap(*__i, *__first);
-            __sift_down<_Compare>(__first, __middle, __comp, __len, __first);
-        }
-    }
-    __sort_heap<_Compare>(__first, __middle, __comp);
-}
-
-template <class _RandomAccessIterator, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-partial_sort(_RandomAccessIterator __first, _RandomAccessIterator __middle, _RandomAccessIterator __last,
-             _Compare __comp)
-{
-#ifdef _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
-    __debug_less<_Compare> __c(__comp);
-    __partial_sort<_Comp_ref>(__first, __middle, __last, __c);
-#else  // _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
-    __partial_sort<_Comp_ref>(__first, __middle, __last, __comp);
-#endif  // _LIBCPP_DEBUG
-}
-
-template <class _RandomAccessIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-partial_sort(_RandomAccessIterator __first, _RandomAccessIterator __middle, _RandomAccessIterator __last)
-{
-    _VSTD::partial_sort(__first, __middle, __last,
-                       __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
-}
-
-// partial_sort_copy
-
-template <class _Compare, class _InputIterator, class _RandomAccessIterator>
-_RandomAccessIterator
-__partial_sort_copy(_InputIterator __first, _InputIterator __last,
-                    _RandomAccessIterator __result_first, _RandomAccessIterator __result_last, _Compare __comp)
-{
-    _RandomAccessIterator __r = __result_first;
-    if (__r != __result_last)
-    {
-        for (; __first != __last && __r != __result_last; (void) ++__first, ++__r)
-            *__r = *__first;
-        __make_heap<_Compare>(__result_first, __r, __comp);
-        typename iterator_traits<_RandomAccessIterator>::difference_type __len = __r - __result_first;
-        for (; __first != __last; ++__first)
-            if (__comp(*__first, *__result_first))
-            {
-                *__result_first = *__first;
-                __sift_down<_Compare>(__result_first, __r, __comp, __len, __result_first);
-            }
-        __sort_heap<_Compare>(__result_first, __r, __comp);
-    }
-    return __r;
-}
-
-template <class _InputIterator, class _RandomAccessIterator, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY
-_RandomAccessIterator
-partial_sort_copy(_InputIterator __first, _InputIterator __last,
-                  _RandomAccessIterator __result_first, _RandomAccessIterator __result_last, _Compare __comp)
-{
-#ifdef _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
-    __debug_less<_Compare> __c(__comp);
-    return __partial_sort_copy<_Comp_ref>(__first, __last, __result_first, __result_last, __c);
-#else  // _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
-    return __partial_sort_copy<_Comp_ref>(__first, __last, __result_first, __result_last, __comp);
-#endif  // _LIBCPP_DEBUG
-}
-
-template <class _InputIterator, class _RandomAccessIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-_RandomAccessIterator
-partial_sort_copy(_InputIterator __first, _InputIterator __last,
-                  _RandomAccessIterator __result_first, _RandomAccessIterator __result_last)
-{
-    return _VSTD::partial_sort_copy(__first, __last, __result_first, __result_last,
-                                   __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
-}
-
-// nth_element
-
-template <class _Compare, class _RandomAccessIterator>
-void
-__nth_element(_RandomAccessIterator __first, _RandomAccessIterator __nth, _RandomAccessIterator __last, _Compare __comp)
-{
-    // _Compare is known to be a reference type
-    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
-    const difference_type __limit = 7;
-    while (true)
-    {
-    __restart:
-        if (__nth == __last)
-            return;
-        difference_type __len = __last - __first;
-        switch (__len)
-        {
-        case 0:
-        case 1:
-            return;
-        case 2:
-            if (__comp(*--__last, *__first))
-                swap(*__first, *__last);
-            return;
-        case 3:
-            {
-            _RandomAccessIterator __m = __first;
-            _VSTD::__sort3<_Compare>(__first, ++__m, --__last, __comp);
-            return;
-            }
-        }
-        if (__len <= __limit)
-        {
-            __selection_sort<_Compare>(__first, __last, __comp);
-            return;
-        }
-        // __len > __limit >= 3
-        _RandomAccessIterator __m = __first + __len/2;
-        _RandomAccessIterator __lm1 = __last;
-        unsigned __n_swaps = _VSTD::__sort3<_Compare>(__first, __m, --__lm1, __comp);
-        // *__m is median
-        // partition [__first, __m) < *__m and *__m <= [__m, __last)
-        // (this inhibits tossing elements equivalent to __m around unnecessarily)
-        _RandomAccessIterator __i = __first;
-        _RandomAccessIterator __j = __lm1;
-        // j points beyond range to be tested, *__lm1 is known to be <= *__m
-        // The search going up is known to be guarded but the search coming down isn't.
-        // Prime the downward search with a guard.
-        if (!__comp(*__i, *__m))  // if *__first == *__m
-        {
-            // *__first == *__m, *__first doesn't go in first part
-            // manually guard downward moving __j against __i
-            while (true)
-            {
-                if (__i == --__j)
-                {
-                    // *__first == *__m, *__m <= all other elements
-                    // Parition instead into [__first, __i) == *__first and *__first < [__i, __last)
-                    ++__i;  // __first + 1
-                    __j = __last;
-                    if (!__comp(*__first, *--__j))  // we need a guard if *__first == *(__last-1)
-                    {
-                        while (true)
-                        {
-                            if (__i == __j)
-                                return;  // [__first, __last) all equivalent elements
-                            if (__comp(*__first, *__i))
-                            {
-                                swap(*__i, *__j);
-                                ++__n_swaps;
-                                ++__i;
-                                break;
-                            }
-                            ++__i;
-                        }
-                    }
-                    // [__first, __i) == *__first and *__first < [__j, __last) and __j == __last - 1
-                    if (__i == __j)
-                        return;
-                    while (true)
-                    {
-                        while (!__comp(*__first, *__i))
-                            ++__i;
-                        while (__comp(*__first, *--__j))
-                            ;
-                        if (__i >= __j)
-                            break;
-                        swap(*__i, *__j);
-                        ++__n_swaps;
-                        ++__i;
-                    }
-                    // [__first, __i) == *__first and *__first < [__i, __last)
-                    // The first part is sorted,
-                    if (__nth < __i)
-                        return;
-                    // __nth_element the secod part
-                    // __nth_element<_Compare>(__i, __nth, __last, __comp);
-                    __first = __i;
-                    goto __restart;
-                }
-                if (__comp(*__j, *__m))
-                {
-                    swap(*__i, *__j);
-                    ++__n_swaps;
-                    break;  // found guard for downward moving __j, now use unguarded partition
-                }
-            }
-        }
-        ++__i;
-        // j points beyond range to be tested, *__lm1 is known to be <= *__m
-        // if not yet partitioned...
-        if (__i < __j)
-        {
-            // known that *(__i - 1) < *__m
-            while (true)
-            {
-                // __m still guards upward moving __i
-                while (__comp(*__i, *__m))
-                    ++__i;
-                // It is now known that a guard exists for downward moving __j
-                while (!__comp(*--__j, *__m))
-                    ;
-                if (__i >= __j)
-                    break;
-                swap(*__i, *__j);
-                ++__n_swaps;
-                // It is known that __m != __j
-                // If __m just moved, follow it
-                if (__m == __i)
-                    __m = __j;
-                ++__i;
-            }
-        }
-        // [__first, __i) < *__m and *__m <= [__i, __last)
-        if (__i != __m && __comp(*__m, *__i))
-        {
-            swap(*__i, *__m);
-            ++__n_swaps;
-        }
-        // [__first, __i) < *__i and *__i <= [__i+1, __last)
-        if (__nth == __i)
-            return;
-        if (__n_swaps == 0)
-        {
-            // We were given a perfectly partitioned sequence.  Coincidence?
-            if (__nth < __i)
-            {
-                // Check for [__first, __i) already sorted
-                __j = __m = __first;
-                while (++__j != __i)
-                {
-                    if (__comp(*__j, *__m))
-                        // not yet sorted, so sort
-                        goto not_sorted;
-                    __m = __j;
-                }
-                // [__first, __i) sorted
-                return;
-            }
-            else
-            {
-                // Check for [__i, __last) already sorted
-                __j = __m = __i;
-                while (++__j != __last)
-                {
-                    if (__comp(*__j, *__m))
-                        // not yet sorted, so sort
-                        goto not_sorted;
-                    __m = __j;
-                }
-                // [__i, __last) sorted
-                return;
-            }
-        }
-not_sorted:
-        // __nth_element on range containing __nth
-        if (__nth < __i)
-        {
-            // __nth_element<_Compare>(__first, __nth, __i, __comp);
-            __last = __i;
-        }
-        else
-        {
-            // __nth_element<_Compare>(__i+1, __nth, __last, __comp);
-            __first = ++__i;
-        }
-    }
-}
-
-template <class _RandomAccessIterator, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-nth_element(_RandomAccessIterator __first, _RandomAccessIterator __nth, _RandomAccessIterator __last, _Compare __comp)
-{
-#ifdef _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
-    __debug_less<_Compare> __c(__comp);
-    __nth_element<_Comp_ref>(__first, __nth, __last, __c);
-#else  // _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
-    __nth_element<_Comp_ref>(__first, __nth, __last, __comp);
-#endif  // _LIBCPP_DEBUG
-}
-
-template <class _RandomAccessIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-nth_element(_RandomAccessIterator __first, _RandomAccessIterator __nth, _RandomAccessIterator __last)
-{
-    _VSTD::nth_element(__first, __nth, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
-}
-
-// includes
-
-template <class _Compare, class _InputIterator1, class _InputIterator2>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
-__includes(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2,
-           _Compare __comp)
-{
-    for (; __first2 != __last2; ++__first1)
-    {
-        if (__first1 == __last1 || __comp(*__first2, *__first1))
-            return false;
-        if (!__comp(*__first1, *__first2))
-            ++__first2;
-    }
-    return true;
-}
-
-template <class _InputIterator1, class _InputIterator2, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-includes(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2,
-         _Compare __comp)
-{
-#ifdef _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
-    __debug_less<_Compare> __c(__comp);
-    return __includes<_Comp_ref>(__first1, __last1, __first2, __last2, __c);
-#else  // _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
-    return __includes<_Comp_ref>(__first1, __last1, __first2, __last2, __comp);
-#endif  // _LIBCPP_DEBUG
-}
-
-template <class _InputIterator1, class _InputIterator2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-includes(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2)
-{
-    return _VSTD::includes(__first1, __last1, __first2, __last2,
-                          __less<typename iterator_traits<_InputIterator1>::value_type,
-                                 typename iterator_traits<_InputIterator2>::value_type>());
-}
-
-// set_union
-
-template <class _Compare, class _InputIterator1, class _InputIterator2, class _OutputIterator>
-_OutputIterator
-__set_union(_InputIterator1 __first1, _InputIterator1 __last1,
-            _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
-{
-    for (; __first1 != __last1; ++__result)
-    {
-        if (__first2 == __last2)
-            return _VSTD::copy(__first1, __last1, __result);
-        if (__comp(*__first2, *__first1))
-        {
-            *__result = *__first2;
-            ++__first2;
-        }
-        else
-        {
-            if (!__comp(*__first1, *__first2))
-                ++__first2;
-            *__result = *__first1;
-            ++__first1;
-        }
-    }
-    return _VSTD::copy(__first2, __last2, __result);
-}
-
-template <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY
-_OutputIterator
-set_union(_InputIterator1 __first1, _InputIterator1 __last1,
-          _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
-{
-#ifdef _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
-    __debug_less<_Compare> __c(__comp);
-    return __set_union<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __c);
-#else  // _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
-    return __set_union<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __comp);
-#endif  // _LIBCPP_DEBUG
-}
-
-template <class _InputIterator1, class _InputIterator2, class _OutputIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-_OutputIterator
-set_union(_InputIterator1 __first1, _InputIterator1 __last1,
-          _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result)
-{
-    return _VSTD::set_union(__first1, __last1, __first2, __last2, __result,
-                          __less<typename iterator_traits<_InputIterator1>::value_type,
-                                 typename iterator_traits<_InputIterator2>::value_type>());
-}
-
-// set_intersection
-
-template <class _Compare, class _InputIterator1, class _InputIterator2, class _OutputIterator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 _OutputIterator
-__set_intersection(_InputIterator1 __first1, _InputIterator1 __last1,
-                   _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
-{
-    while (__first1 != __last1 && __first2 != __last2)
-    {
-        if (__comp(*__first1, *__first2))
-            ++__first1;
-        else
-        {
-            if (!__comp(*__first2, *__first1))
-            {
-                *__result = *__first1;
-                ++__result;
-                ++__first1;
-            }
-            ++__first2;
-        }
-    }
-    return __result;
-}
-
-template <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_OutputIterator
-set_intersection(_InputIterator1 __first1, _InputIterator1 __last1,
-                 _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
-{
-#ifdef _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
-    __debug_less<_Compare> __c(__comp);
-    return __set_intersection<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __c);
-#else  // _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
-    return __set_intersection<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __comp);
-#endif  // _LIBCPP_DEBUG
-}
-
-template <class _InputIterator1, class _InputIterator2, class _OutputIterator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_OutputIterator
-set_intersection(_InputIterator1 __first1, _InputIterator1 __last1,
-                 _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result)
-{
-    return _VSTD::set_intersection(__first1, __last1, __first2, __last2, __result,
-                                  __less<typename iterator_traits<_InputIterator1>::value_type,
-                                         typename iterator_traits<_InputIterator2>::value_type>());
-}
-
-// set_difference
-
-template <class _Compare, class _InputIterator1, class _InputIterator2, class _OutputIterator>
-_OutputIterator
-__set_difference(_InputIterator1 __first1, _InputIterator1 __last1,
-                 _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
-{
-    while (__first1 != __last1)
-    {
-        if (__first2 == __last2)
-            return _VSTD::copy(__first1, __last1, __result);
-        if (__comp(*__first1, *__first2))
-        {
-            *__result = *__first1;
-            ++__result;
-            ++__first1;
-        }
-        else
-        {
-            if (!__comp(*__first2, *__first1))
-                ++__first1;
-            ++__first2;
-        }
-    }
-    return __result;
-}
-
-template <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY
-_OutputIterator
-set_difference(_InputIterator1 __first1, _InputIterator1 __last1,
-               _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
-{
-#ifdef _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
-    __debug_less<_Compare> __c(__comp);
-    return __set_difference<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __c);
-#else  // _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
-    return __set_difference<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __comp);
-#endif  // _LIBCPP_DEBUG
-}
-
-template <class _InputIterator1, class _InputIterator2, class _OutputIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-_OutputIterator
-set_difference(_InputIterator1 __first1, _InputIterator1 __last1,
-               _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result)
-{
-    return _VSTD::set_difference(__first1, __last1, __first2, __last2, __result,
-                                __less<typename iterator_traits<_InputIterator1>::value_type,
-                                       typename iterator_traits<_InputIterator2>::value_type>());
-}
-
-// set_symmetric_difference
-
-template <class _Compare, class _InputIterator1, class _InputIterator2, class _OutputIterator>
-_OutputIterator
-__set_symmetric_difference(_InputIterator1 __first1, _InputIterator1 __last1,
-                           _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
-{
-    while (__first1 != __last1)
-    {
-        if (__first2 == __last2)
-            return _VSTD::copy(__first1, __last1, __result);
-        if (__comp(*__first1, *__first2))
-        {
-            *__result = *__first1;
-            ++__result;
-            ++__first1;
-        }
-        else
-        {
-            if (__comp(*__first2, *__first1))
-            {
-                *__result = *__first2;
-                ++__result;
-            }
-            else
-                ++__first1;
-            ++__first2;
-        }
-    }
-    return _VSTD::copy(__first2, __last2, __result);
-}
-
-template <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY
-_OutputIterator
-set_symmetric_difference(_InputIterator1 __first1, _InputIterator1 __last1,
-                         _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
-{
-#ifdef _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
-    __debug_less<_Compare> __c(__comp);
-    return __set_symmetric_difference<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __c);
-#else  // _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
-    return __set_symmetric_difference<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __comp);
-#endif  // _LIBCPP_DEBUG
-}
-
-template <class _InputIterator1, class _InputIterator2, class _OutputIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-_OutputIterator
-set_symmetric_difference(_InputIterator1 __first1, _InputIterator1 __last1,
-                         _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result)
-{
-    return _VSTD::set_symmetric_difference(__first1, __last1, __first2, __last2, __result,
-                                          __less<typename iterator_traits<_InputIterator1>::value_type,
-                                                 typename iterator_traits<_InputIterator2>::value_type>());
-}
-
-// lexicographical_compare
-
-template <class _Compare, class _InputIterator1, class _InputIterator2>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
-__lexicographical_compare(_InputIterator1 __first1, _InputIterator1 __last1,
-                          _InputIterator2 __first2, _InputIterator2 __last2, _Compare __comp)
-{
-    for (; __first2 != __last2; ++__first1, (void) ++__first2)
-    {
-        if (__first1 == __last1 || __comp(*__first1, *__first2))
-            return true;
-        if (__comp(*__first2, *__first1))
-            return false;
-    }
-    return false;
-}
-
-template <class _InputIterator1, class _InputIterator2, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-lexicographical_compare(_InputIterator1 __first1, _InputIterator1 __last1,
-                        _InputIterator2 __first2, _InputIterator2 __last2, _Compare __comp)
-{
-#ifdef _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
-    __debug_less<_Compare> __c(__comp);
-    return __lexicographical_compare<_Comp_ref>(__first1, __last1, __first2, __last2, __c);
-#else  // _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
-    return __lexicographical_compare<_Comp_ref>(__first1, __last1, __first2, __last2, __comp);
-#endif  // _LIBCPP_DEBUG
-}
-
-template <class _InputIterator1, class _InputIterator2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-lexicographical_compare(_InputIterator1 __first1, _InputIterator1 __last1,
-                        _InputIterator2 __first2, _InputIterator2 __last2)
-{
-    return _VSTD::lexicographical_compare(__first1, __last1, __first2, __last2,
-                                         __less<typename iterator_traits<_InputIterator1>::value_type,
-                                                typename iterator_traits<_InputIterator2>::value_type>());
-}
-
-// next_permutation
-
-template <class _Compare, class _BidirectionalIterator>
-bool
-__next_permutation(_BidirectionalIterator __first, _BidirectionalIterator __last, _Compare __comp)
-{
-    _BidirectionalIterator __i = __last;
-    if (__first == __last || __first == --__i)
-        return false;
-    while (true)
-    {
-        _BidirectionalIterator __ip1 = __i;
-        if (__comp(*--__i, *__ip1))
-        {
-            _BidirectionalIterator __j = __last;
-            while (!__comp(*__i, *--__j))
-                ;
-            swap(*__i, *__j);
-            _VSTD::reverse(__ip1, __last);
-            return true;
-        }
-        if (__i == __first)
-        {
-            _VSTD::reverse(__first, __last);
-            return false;
-        }
-    }
-}
-
-template <class _BidirectionalIterator, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-next_permutation(_BidirectionalIterator __first, _BidirectionalIterator __last, _Compare __comp)
-{
-#ifdef _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
-    __debug_less<_Compare> __c(__comp);
-    return __next_permutation<_Comp_ref>(__first, __last, __c);
-#else  // _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
-    return __next_permutation<_Comp_ref>(__first, __last, __comp);
-#endif  // _LIBCPP_DEBUG
-}
-
-template <class _BidirectionalIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-next_permutation(_BidirectionalIterator __first, _BidirectionalIterator __last)
-{
-    return _VSTD::next_permutation(__first, __last,
-                                  __less<typename iterator_traits<_BidirectionalIterator>::value_type>());
-}
-
-// prev_permutation
-
-template <class _Compare, class _BidirectionalIterator>
-bool
-__prev_permutation(_BidirectionalIterator __first, _BidirectionalIterator __last, _Compare __comp)
-{
-    _BidirectionalIterator __i = __last;
-    if (__first == __last || __first == --__i)
-        return false;
-    while (true)
-    {
-        _BidirectionalIterator __ip1 = __i;
-        if (__comp(*__ip1, *--__i))
-        {
-            _BidirectionalIterator __j = __last;
-            while (!__comp(*--__j, *__i))
-                ;
-            swap(*__i, *__j);
-            _VSTD::reverse(__ip1, __last);
-            return true;
-        }
-        if (__i == __first)
-        {
-            _VSTD::reverse(__first, __last);
-            return false;
-        }
-    }
-}
-
-template <class _BidirectionalIterator, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-prev_permutation(_BidirectionalIterator __first, _BidirectionalIterator __last, _Compare __comp)
-{
-#ifdef _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
-    __debug_less<_Compare> __c(__comp);
-    return __prev_permutation<_Comp_ref>(__first, __last, __c);
-#else  // _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
-    return __prev_permutation<_Comp_ref>(__first, __last, __comp);
-#endif  // _LIBCPP_DEBUG
-}
-
-template <class _BidirectionalIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-prev_permutation(_BidirectionalIterator __first, _BidirectionalIterator __last)
-{
-    return _VSTD::prev_permutation(__first, __last,
-                                  __less<typename iterator_traits<_BidirectionalIterator>::value_type>());
-}
-
-_LIBCPP_END_NAMESPACE_STD
-
-_LIBCPP_POP_MACROS
-
-#endif  // _LIBCPP_ALGORITHM