llvm-project/libcxx/include/__algorithm/is_heap_until.h

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//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef _LIBCPP___ALGORITHM_IS_HEAP_UNTIL_H
#define _LIBCPP___ALGORITHM_IS_HEAP_UNTIL_H
#include <__config>
#include <__algorithm/comp.h>
#include <__iterator/iterator_traits.h>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
#pragma GCC system_header
#endif
_LIBCPP_BEGIN_NAMESPACE_STD
template <class _RandomAccessIterator, class _Compare>
_LIBCPP_NODISCARD_EXT _LIBCPP_CONSTEXPR_AFTER_CXX17 _RandomAccessIterator
is_heap_until(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
{
typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
difference_type __len = __last - __first;
difference_type __p = 0;
difference_type __c = 1;
_RandomAccessIterator __pp = __first;
while (__c < __len)
{
_RandomAccessIterator __cp = __first + __c;
if (__comp(*__pp, *__cp))
return __cp;
++__c;
++__cp;
if (__c == __len)
return __last;
if (__comp(*__pp, *__cp))
return __cp;
++__p;
++__pp;
__c = 2 * __p + 1;
}
return __last;
}
template<class _RandomAccessIterator>
_LIBCPP_NODISCARD_EXT inline
_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
_RandomAccessIterator
is_heap_until(_RandomAccessIterator __first, _RandomAccessIterator __last)
{
return _VSTD::is_heap_until(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
}
_LIBCPP_END_NAMESPACE_STD
#endif // _LIBCPP___ALGORITHM_IS_HEAP_UNTIL_H