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 22template <class _InputIterator, class _Predicate> 23_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _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