1 // -*- C++ -*- 2 //===----------------------------------------------------------------------===// 3 // 4 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 5 // See https://llvm.org/LICENSE.txt for license information. 6 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 7 // 8 //===----------------------------------------------------------------------===// 9 10 #ifndef _LIBCPP___ALGORITHM_COUNT_IF_H 11 #define _LIBCPP___ALGORITHM_COUNT_IF_H 12 13 #include <__algorithm/iterator_operations.h> 14 #include <__config> 15 #include <__functional/identity.h> 16 #include <__iterator/iterator_traits.h> 17 #include <__type_traits/invoke.h> 18 19 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 20 # pragma GCC system_header 21 #endif 22 23 _LIBCPP_BEGIN_NAMESPACE_STD 24 25 template <class _AlgPolicy, class _Iter, class _Sent, class _Proj, class _Pred> 26 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 __policy_iter_diff_t<_AlgPolicy, _Iter> 27 __count_if(_Iter __first, _Sent __last, _Pred& __pred, _Proj& __proj) { 28 __policy_iter_diff_t<_AlgPolicy, _Iter> __counter(0); 29 for (; __first != __last; ++__first) { 30 if (std::__invoke(__pred, std::__invoke(__proj, *__first))) 31 ++__counter; 32 } 33 return __counter; 34 } 35 36 template <class _InputIterator, class _Predicate> 37 [[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 38 typename iterator_traits<_InputIterator>::difference_type 39 count_if(_InputIterator __first, _InputIterator __last, _Predicate __pred) { 40 __identity __proj; 41 return std::__count_if<_ClassicAlgPolicy>(__first, __last, __pred, __proj); 42 } 43 44 _LIBCPP_END_NAMESPACE_STD 45 46 #endif // _LIBCPP___ALGORITHM_COUNT_IF_H 47