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 
26 template <class _AlgPolicy, class _Compare, class _RandomAccessIterator>
27 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14
28 void __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 
41 template <class _RandomAccessIterator, class _Compare>
42 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20
43 void make_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp) {
44   std::__make_heap<_ClassicAlgPolicy>(std::move(__first), std::move(__last), __comp);
45 }
46 
47 template <class _RandomAccessIterator>
48 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20
49 void 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