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_PARTITION_POINT_H 10 #define _LIBCPP___ALGORITHM_PARTITION_POINT_H 11 12 #include <__algorithm/half_positive.h> 13 #include <__config> 14 #include <iterator> 15 16 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 17 # pragma GCC system_header 18 # pragma clang include_instead(<algorithm>) 19 #endif 20 21 _LIBCPP_BEGIN_NAMESPACE_STD 22 23 template<class _ForwardIterator, class _Predicate> 24 _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator 25 partition_point(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred) 26 { 27 typedef typename iterator_traits<_ForwardIterator>::difference_type difference_type; 28 difference_type __len = _VSTD::distance(__first, __last); 29 while (__len != 0) 30 { 31 difference_type __l2 = _VSTD::__half_positive(__len); 32 _ForwardIterator __m = __first; 33 _VSTD::advance(__m, __l2); 34 if (__pred(*__m)) 35 { 36 __first = ++__m; 37 __len -= __l2 + 1; 38 } 39 else 40 __len = __l2; 41 } 42 return __first; 43 } 44 45 _LIBCPP_END_NAMESPACE_STD 46 47 #endif // _LIBCPP___ALGORITHM_PARTITION_POINT_H 48