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 <__config> 14 #include <__iterator/iterator_traits.h> 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 _InputIterator, class _Predicate> 24 _LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 25 typename iterator_traits<_InputIterator>::difference_type 26 count_if(_InputIterator __first, _InputIterator __last, _Predicate __pred) { 27 typename iterator_traits<_InputIterator>::difference_type __r(0); 28 for (; __first != __last; ++__first) 29 if (__pred(*__first)) 30 ++__r; 31 return __r; 32 } 33 34 _LIBCPP_END_NAMESPACE_STD 35 36 #endif // _LIBCPP___ALGORITHM_COUNT_IF_H 37