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 <__utility/move.h>
18 
19 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
20 #  pragma GCC system_header
21 #endif
22 
23 _LIBCPP_BEGIN_NAMESPACE_STD
24 
25 template <class _AlgPolicy, class _Compare, class _RandomAccessIterator>
26 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
27 void __sift_up(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp,
28         typename iterator_traits<_RandomAccessIterator>::difference_type __len) {
29   using value_type = typename iterator_traits<_RandomAccessIterator>::value_type;
30 
31   if (__len > 1) {
32     __len = (__len - 2) / 2;
33     _RandomAccessIterator __ptr = __first + __len;
34 
35     if (__comp(*__ptr, *--__last)) {
36       value_type __t(_IterOps<_AlgPolicy>::__iter_move(__last));
37       do {
38         *__last = _IterOps<_AlgPolicy>::__iter_move(__ptr);
39         __last = __ptr;
40         if (__len == 0)
41           break;
42         __len = (__len - 1) / 2;
43         __ptr = __first + __len;
44       } while (__comp(*__ptr, __t));
45 
46       *__last = std::move(__t);
47     }
48   }
49 }
50 
51 template <class _AlgPolicy, class _RandomAccessIterator, class _Compare>
52 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
53 void __push_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare& __comp) {
54   using _CompRef = typename __comp_ref_type<_Compare>::type;
55   typename iterator_traits<_RandomAccessIterator>::difference_type __len = __last - __first;
56   std::__sift_up<_AlgPolicy, _CompRef>(std::move(__first), std::move(__last), __comp, __len);
57 }
58 
59 template <class _RandomAccessIterator, class _Compare>
60 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
61 void push_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp) {
62   std::__push_heap<_ClassicAlgPolicy>(std::move(__first), std::move(__last), __comp);
63 }
64 
65 template <class _RandomAccessIterator>
66 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
67 void push_heap(_RandomAccessIterator __first, _RandomAccessIterator __last) {
68   std::push_heap(std::move(__first), std::move(__last),
69       __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
70 }
71 
72 _LIBCPP_END_NAMESPACE_STD
73 
74 #endif // _LIBCPP___ALGORITHM_PUSH_HEAP_H
75