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 <__config> 13 #include <__algorithm/half_positive.h> 14 #include <iterator> 15 16 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 17 #pragma GCC system_header 18 #endif 19 20 _LIBCPP_PUSH_MACROS 21 #include <__undef_macros> 22 23 _LIBCPP_BEGIN_NAMESPACE_STD 24 25 template<class _ForwardIterator, class _Predicate> 26 _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator 27 partition_point(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred) 28 { 29 typedef typename iterator_traits<_ForwardIterator>::difference_type difference_type; 30 difference_type __len = _VSTD::distance(__first, __last); 31 while (__len != 0) 32 { 33 difference_type __l2 = _VSTD::__half_positive(__len); 34 _ForwardIterator __m = __first; 35 _VSTD::advance(__m, __l2); 36 if (__pred(*__m)) 37 { 38 __first = ++__m; 39 __len -= __l2 + 1; 40 } 41 else 42 __len = __l2; 43 } 44 return __first; 45 } 46 47 _LIBCPP_END_NAMESPACE_STD 48 49 _LIBCPP_POP_MACROS 50 51 #endif // _LIBCPP___ALGORITHM_PARTITION_POINT_H 52