xref: /llvm-project/libcxx/include/__cxx03/__algorithm/count_if.h (revision ce7771902dc50d900de639d499a60486b83f70e0)
1e78f53d1SNikolas Klauser // -*- C++ -*-
2e78f53d1SNikolas Klauser //===----------------------------------------------------------------------===//
3e78f53d1SNikolas Klauser //
4e78f53d1SNikolas Klauser // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5e78f53d1SNikolas Klauser // See https://llvm.org/LICENSE.txt for license information.
6e78f53d1SNikolas Klauser // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7e78f53d1SNikolas Klauser //
8e78f53d1SNikolas Klauser //===----------------------------------------------------------------------===//
9e78f53d1SNikolas Klauser 
10*ce777190SNikolas Klauser #ifndef _LIBCPP___CXX03___ALGORITHM_COUNT_IF_H
11*ce777190SNikolas Klauser #define _LIBCPP___CXX03___ALGORITHM_COUNT_IF_H
12e78f53d1SNikolas Klauser 
1373fbae83SNikolas Klauser #include <__cxx03/__config>
1473fbae83SNikolas Klauser #include <__cxx03/__iterator/iterator_traits.h>
15e78f53d1SNikolas Klauser 
16e78f53d1SNikolas Klauser #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
17e78f53d1SNikolas Klauser #  pragma GCC system_header
18e78f53d1SNikolas Klauser #endif
19e78f53d1SNikolas Klauser 
20e78f53d1SNikolas Klauser _LIBCPP_BEGIN_NAMESPACE_STD
21e78f53d1SNikolas Klauser 
22e78f53d1SNikolas Klauser template <class _InputIterator, class _Predicate>
23e78f53d1SNikolas Klauser _LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20
24e78f53d1SNikolas Klauser typename iterator_traits<_InputIterator>::difference_type
25e78f53d1SNikolas Klauser count_if(_InputIterator __first, _InputIterator __last, _Predicate __pred) {
26e78f53d1SNikolas Klauser   typename iterator_traits<_InputIterator>::difference_type __r(0);
27e78f53d1SNikolas Klauser   for (; __first != __last; ++__first)
28e78f53d1SNikolas Klauser     if (__pred(*__first))
29e78f53d1SNikolas Klauser       ++__r;
30e78f53d1SNikolas Klauser   return __r;
31e78f53d1SNikolas Klauser }
32e78f53d1SNikolas Klauser 
33e78f53d1SNikolas Klauser _LIBCPP_END_NAMESPACE_STD
34e78f53d1SNikolas Klauser 
35*ce777190SNikolas Klauser #endif // _LIBCPP___CXX03___ALGORITHM_COUNT_IF_H
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