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 #endif 19 20 _LIBCPP_BEGIN_NAMESPACE_STD 21 22 template<class _ForwardIterator, class _Predicate> 23 _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator 24 partition_point(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred) 25 { 26 typedef typename iterator_traits<_ForwardIterator>::difference_type difference_type; 27 difference_type __len = _VSTD::distance(__first, __last); 28 while (__len != 0) 29 { 30 difference_type __l2 = _VSTD::__half_positive(__len); 31 _ForwardIterator __m = __first; 32 _VSTD::advance(__m, __l2); 33 if (__pred(*__m)) 34 { 35 __first = ++__m; 36 __len -= __l2 + 1; 37 } 38 else 39 __len = __l2; 40 } 41 return __first; 42 } 43 44 _LIBCPP_END_NAMESPACE_STD 45 46 #endif // _LIBCPP___ALGORITHM_PARTITION_POINT_H 47