v1/__algorithm/is_heap_until.h

0001 //===----------------------------------------------------------------------===//
0002 //
0003 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
0004 // See https://llvm.org/LICENSE.txt for license information.
0005 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
0006 //
0007 //===----------------------------------------------------------------------===//
0008
0009 #ifndef _LIBCPP___ALGORITHM_IS_HEAP_UNTIL_H
0010 #define _LIBCPP___ALGORITHM_IS_HEAP_UNTIL_H
0011
0012 #include <__algorithm/comp.h>
0013 #include <__algorithm/comp_ref_type.h>
0014 #include <__config>
0015 #include <__iterator/iterator_traits.h>
0016
0017 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
0018 #  pragma GCC system_header
0019 #endif
0020
0021 _LIBCPP_BEGIN_NAMESPACE_STD
0022
0023 template <class _Compare, class _RandomAccessIterator>
0024 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _RandomAccessIterator
0025 __is_heap_until(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare&& __comp) {
0026   typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
0027   difference_type __len      = __last - __first;
0028   difference_type __p        = 0;
0029   difference_type __c        = 1;
0030   _RandomAccessIterator __pp = __first;
0031   while (__c < __len) {
0032     _RandomAccessIterator __cp = __first + __c;
0033     if (__comp(*__pp, *__cp))
0034       return __cp;
0035     ++__c;
0036     ++__cp;
0037     if (__c == __len)
0038       return __last;
0039     if (__comp(*__pp, *__cp))
0040       return __cp;
0041     ++__p;
0042     ++__pp;
0043     __c = 2 * __p + 1;
0044   }
0045   return __last;
0046 }
0047
0048 template <class _RandomAccessIterator, class _Compare>
0049 [[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _RandomAccessIterator
0050 is_heap_until(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp) {
0051   return std::__is_heap_until(__first, __last, static_cast<__comp_ref_type<_Compare> >(__comp));
0052 }
0053
0054 template <class _RandomAccessIterator>
0055 [[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _RandomAccessIterator
0056 is_heap_until(_RandomAccessIterator __first, _RandomAccessIterator __last) {
0057   return std::__is_heap_until(__first, __last, __less<>());
0058 }
0059
0060 _LIBCPP_END_NAMESPACE_STD
0061
0062 #endif // _LIBCPP___ALGORITHM_IS_HEAP_UNTIL_H