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/sift_down.h> 15 #include <__config> 16 #include <__iterator/iterator_traits.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_CONSTEXPR_AFTER_CXX11 void 26 __make_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp) 27 { 28 typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type; 29 difference_type __n = __last - __first; 30 if (__n > 1) 31 { 32 // start from the first parent, there is no need to consider children 33 for (difference_type __start = (__n - 2) / 2; __start >= 0; --__start) 34 { 35 _VSTD::__sift_down<_Compare>(__first, __comp, __n, __first + __start); 36 } 37 } 38 } 39 40 template <class _RandomAccessIterator, class _Compare> 41 inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 42 void 43 make_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp) 44 { 45 typedef typename __comp_ref_type<_Compare>::type _Comp_ref; 46 _VSTD::__make_heap<_Comp_ref>(__first, __last, __comp); 47 } 48 49 template <class _RandomAccessIterator> 50 inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 51 void 52 make_heap(_RandomAccessIterator __first, _RandomAccessIterator __last) 53 { 54 _VSTD::make_heap(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>()); 55 } 56 57 _LIBCPP_END_NAMESPACE_STD 58 59 #endif // _LIBCPP___ALGORITHM_MAKE_HEAP_H 60