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_POP_HEAP_H 10 #define _LIBCPP___ALGORITHM_POP_HEAP_H 11 12 #include <__algorithm/comp.h> 13 #include <__algorithm/comp_ref_type.h> 14 #include <__algorithm/iterator_operations.h> 15 #include <__algorithm/push_heap.h> 16 #include <__algorithm/sift_down.h> 17 #include <__assert> 18 #include <__config> 19 #include <__iterator/iterator_traits.h> 20 #include <__utility/move.h> 21 #include <type_traits> 22 23 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 24 # pragma GCC system_header 25 #endif 26 27 _LIBCPP_BEGIN_NAMESPACE_STD 28 29 template <class _AlgPolicy, class _Compare, class _RandomAccessIterator> 30 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 31 void __pop_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare& __comp, 32 typename iterator_traits<_RandomAccessIterator>::difference_type __len) { 33 _LIBCPP_ASSERT(__len > 0, "The heap given to pop_heap must be non-empty"); 34 35 __comp_ref_type<_Compare> __comp_ref = __comp; 36 37 using value_type = typename iterator_traits<_RandomAccessIterator>::value_type; 38 if (__len > 1) { 39 value_type __top = _IterOps<_AlgPolicy>::__iter_move(__first); // create a hole at __first 40 _RandomAccessIterator __hole = std::__floyd_sift_down<_AlgPolicy>(__first, __comp_ref, __len); 41 --__last; 42 43 if (__hole == __last) { 44 *__hole = std::move(__top); 45 } else { 46 *__hole = _IterOps<_AlgPolicy>::__iter_move(__last); 47 ++__hole; 48 *__last = std::move(__top); 49 std::__sift_up<_AlgPolicy>(__first, __hole, __comp_ref, __hole - __first); 50 } 51 } 52 } 53 54 template <class _RandomAccessIterator, class _Compare> 55 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 56 void pop_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp) { 57 static_assert(std::is_copy_constructible<_RandomAccessIterator>::value, "Iterators must be copy constructible."); 58 static_assert(std::is_copy_assignable<_RandomAccessIterator>::value, "Iterators must be copy assignable."); 59 60 typename iterator_traits<_RandomAccessIterator>::difference_type __len = __last - __first; 61 std::__pop_heap<_ClassicAlgPolicy>(std::move(__first), std::move(__last), __comp, __len); 62 } 63 64 template <class _RandomAccessIterator> 65 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 66 void pop_heap(_RandomAccessIterator __first, _RandomAccessIterator __last) { 67 std::pop_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_POP_HEAP_H 74