xref: /freebsd-src/contrib/llvm-project/libcxx/include/__algorithm/push_heap.h (revision 753f127f3ace09432b2baeffd71a308760641a62)
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 <__config>
15 #include <__iterator/iterator_traits.h>
16 #include <__utility/move.h>
17 
18 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
19 #  pragma GCC system_header
20 #endif
21 
22 _LIBCPP_BEGIN_NAMESPACE_STD
23 
24 template <class _Compare, class _RandomAccessIterator>
25 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
26 void __sift_up(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp,
27         typename iterator_traits<_RandomAccessIterator>::difference_type __len) {
28   using value_type = typename iterator_traits<_RandomAccessIterator>::value_type;
29 
30   if (__len > 1) {
31     __len = (__len - 2) / 2;
32     _RandomAccessIterator __ptr = __first + __len;
33 
34     if (__comp(*__ptr, *--__last)) {
35       value_type __t(std::move(*__last));
36       do {
37         *__last = std::move(*__ptr);
38         __last = __ptr;
39         if (__len == 0)
40           break;
41         __len = (__len - 1) / 2;
42         __ptr = __first + __len;
43       } while (__comp(*__ptr, __t));
44 
45       *__last = std::move(__t);
46     }
47   }
48 }
49 
50 template <class _RandomAccessIterator, class _Compare>
51 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
52 void __push_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare& __comp) {
53   using _CompRef = typename __comp_ref_type<_Compare>::type;
54   typename iterator_traits<_RandomAccessIterator>::difference_type __len = __last - __first;
55   std::__sift_up<_CompRef>(std::move(__first), std::move(__last), __comp, __len);
56 }
57 
58 template <class _RandomAccessIterator, class _Compare>
59 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
60 void push_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp) {
61   std::__push_heap(std::move(__first), std::move(__last), __comp);
62 }
63 
64 template <class _RandomAccessIterator>
65 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
66 void push_heap(_RandomAccessIterator __first, _RandomAccessIterator __last) {
67   std::push_heap(std::move(__first), std::move(__last),
68       __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
69 }
70 
71 _LIBCPP_END_NAMESPACE_STD
72 
73 #endif // _LIBCPP___ALGORITHM_PUSH_HEAP_H
74