1//===----------------------------------------------------------------------===//
 2//
 3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 4// See https://llvm.org/LICENSE.txt for license information.
 5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 6//
 7//===----------------------------------------------------------------------===//
 8
 9#ifndef _LIBCPP___ALGORITHM_PUSH_HEAP_H
10#define _LIBCPP___ALGORITHM_PUSH_HEAP_H
11
12#include <__algorithm/comp.h>
13#include <__algorithm/comp_ref_type.h>
14#include <__algorithm/iterator_operations.h>
15#include <__config>
16#include <__iterator/iterator_traits.h>
17#include <__type_traits/is_assignable.h>
18#include <__type_traits/is_constructible.h>
19#include <__utility/move.h>
20
21#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
22#  pragma GCC system_header
23#endif
24
25_LIBCPP_PUSH_MACROS
26#include <__undef_macros>
27
28_LIBCPP_BEGIN_NAMESPACE_STD
29
30template <class _AlgPolicy, class _Compare, class _RandomAccessIterator>
31_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 void
32__sift_up(_RandomAccessIterator __first,
33          _RandomAccessIterator __last,
34          _Compare&& __comp,
35          typename iterator_traits<_RandomAccessIterator>::difference_type __len) {
36  using value_type = typename iterator_traits<_RandomAccessIterator>::value_type;
37
38  if (__len > 1) {
39    __len                       = (__len - 2) / 2;
40    _RandomAccessIterator __ptr = __first + __len;
41
42    if (__comp(*__ptr, *--__last)) {
43      value_type __t(_IterOps<_AlgPolicy>::__iter_move(__last));
44      do {
45        *__last = _IterOps<_AlgPolicy>::__iter_move(__ptr);
46        __last  = __ptr;
47        if (__len == 0)
48          break;
49        __len = (__len - 1) / 2;
50        __ptr = __first + __len;
51      } while (__comp(*__ptr, __t));
52
53      *__last = std::move(__t);
54    }
55  }
56}
57
58template <class _AlgPolicy, class _RandomAccessIterator, class _Compare>
59inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 void
60__push_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare& __comp) {
61  typename iterator_traits<_RandomAccessIterator>::difference_type __len = __last - __first;
62  std::__sift_up<_AlgPolicy, __comp_ref_type<_Compare> >(std::move(__first), std::move(__last), __comp, __len);
63}
64
65template <class _RandomAccessIterator, class _Compare>
66inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void
67push_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp) {
68  static_assert(std::is_copy_constructible<_RandomAccessIterator>::value, "Iterators must be copy constructible.");
69  static_assert(std::is_copy_assignable<_RandomAccessIterator>::value, "Iterators must be copy assignable.");
70
71  std::__push_heap<_ClassicAlgPolicy>(std::move(__first), std::move(__last), __comp);
72}
73
74template <class _RandomAccessIterator>
75inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void
76push_heap(_RandomAccessIterator __first, _RandomAccessIterator __last) {
77  std::push_heap(std::move(__first), std::move(__last), __less<>());
78}
79
80_LIBCPP_END_NAMESPACE_STD
81
82_LIBCPP_POP_MACROS
83
84#endif // _LIBCPP___ALGORITHM_PUSH_HEAP_H