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 #endif 19 20 _LIBCPP_BEGIN_NAMESPACE_STD 21 22 template <class _InputIterator, class _Predicate> 23 _LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX20 24 typename iterator_traits<_InputIterator>::difference_type 25 count_if(_InputIterator __first, _InputIterator __last, _Predicate __pred) { 26 typename iterator_traits<_InputIterator>::difference_type __r(0); 27 for (; __first != __last; ++__first) 28 if (__pred(*__first)) 29 ++__r; 30 return __r; 31 } 32 33 _LIBCPP_END_NAMESPACE_STD 34 35 #endif // _LIBCPP___ALGORITHM_COUNT_IF_H 36