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_MAKE_HEAP_H
10#define _LIBCPP___ALGORITHM_MAKE_HEAP_H
11
12#include <__algorithm/comp.h>
13#include <__algorithm/comp_ref_type.h>
14#include <__algorithm/iterator_operations.h>
15#include <__algorithm/sift_down.h>
16#include <__config>
17#include <__iterator/iterator_traits.h>
18#include <__utility/move.h>
19
20#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
21#  pragma GCC system_header
22#endif
23
24_LIBCPP_BEGIN_NAMESPACE_STD
25
26template <class _AlgPolicy, class _Compare, class _RandomAccessIterator>
27inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14
28void __make_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare&& __comp) {
29  __comp_ref_type<_Compare> __comp_ref = __comp;
30
31  using difference_type = typename iterator_traits<_RandomAccessIterator>::difference_type;
32  difference_type __n = __last - __first;
33  if (__n > 1) {
34    // start from the first parent, there is no need to consider children
35    for (difference_type __start = (__n - 2) / 2; __start >= 0; --__start) {
36        std::__sift_down<_AlgPolicy>(__first, __comp_ref, __n, __first + __start);
37    }
38  }
39}
40
41template <class _RandomAccessIterator, class _Compare>
42inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20
43void make_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp) {
44  std::__make_heap<_ClassicAlgPolicy>(std::move(__first), std::move(__last), __comp);
45}
46
47template <class _RandomAccessIterator>
48inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20
49void make_heap(_RandomAccessIterator __first, _RandomAccessIterator __last) {
50  std::make_heap(std::move(__first), std::move(__last),
51      __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
52}
53
54_LIBCPP_END_NAMESPACE_STD
55
56#endif // _LIBCPP___ALGORITHM_MAKE_HEAP_H
57