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_IS_HEAP_UNTIL_H 10 #define _LIBCPP___ALGORITHM_IS_HEAP_UNTIL_H 11 12 #include <__config> 13 #include <__algorithm/comp.h> 14 #include <__iterator/iterator_traits.h> 15 16 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 17 #pragma GCC system_header 18 #endif 19 20 _LIBCPP_BEGIN_NAMESPACE_STD 21 22 template <class _RandomAccessIterator, class _Compare> 23 _LIBCPP_NODISCARD_EXT _LIBCPP_CONSTEXPR_AFTER_CXX17 _RandomAccessIterator 24 is_heap_until(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp) 25 { 26 typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type; 27 difference_type __len = __last - __first; 28 difference_type __p = 0; 29 difference_type __c = 1; 30 _RandomAccessIterator __pp = __first; 31 while (__c < __len) 32 { 33 _RandomAccessIterator __cp = __first + __c; 34 if (__comp(*__pp, *__cp)) 35 return __cp; 36 ++__c; 37 ++__cp; 38 if (__c == __len) 39 return __last; 40 if (__comp(*__pp, *__cp)) 41 return __cp; 42 ++__p; 43 ++__pp; 44 __c = 2 * __p + 1; 45 } 46 return __last; 47 } 48 49 template<class _RandomAccessIterator> 50 _LIBCPP_NODISCARD_EXT inline 51 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 52 _RandomAccessIterator 53 is_heap_until(_RandomAccessIterator __first, _RandomAccessIterator __last) 54 { 55 return _VSTD::is_heap_until(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>()); 56 } 57 58 _LIBCPP_END_NAMESPACE_STD 59 60 #endif // _LIBCPP___ALGORITHM_IS_HEAP_UNTIL_H 61