1 // Copyright Neil Groves 2009. Use, modification and
2 // distribution is subject to the Boost Software License, Version
3 // 1.0. (See accompanying file LICENSE_1_0.txt or copy at
4 // http://www.boost.org/LICENSE_1_0.txt)
5 //
6 //
7 // For more information, see http://www.boost.org/libs/range/
8 //
9 #ifndef BOOST_RANGE_ALGORITHM_COUNT_IF_HPP_INCLUDED
10 #define BOOST_RANGE_ALGORITHM_COUNT_IF_HPP_INCLUDED
11
12 #include <boost/concept_check.hpp>
13 #include <boost/range/begin.hpp>
14 #include <boost/range/end.hpp>
15 #include <boost/range/concepts.hpp>
16 #include <boost/range/difference_type.hpp>
17 #include <algorithm>
18
19 namespace boost
20 {
21 namespace range
22 {
23
24 /// \brief template function count_if
25 ///
26 /// range-based version of the count_if std algorithm
27 ///
28 /// \pre SinglePassRange is a model of the SinglePassRangeConcept
29 /// \pre UnaryPredicate is a model of the UnaryPredicateConcept
30 template< class SinglePassRange, class UnaryPredicate >
31 inline BOOST_DEDUCED_TYPENAME boost::range_difference<SinglePassRange>::type
count_if(SinglePassRange & rng,UnaryPredicate pred)32 count_if(SinglePassRange& rng, UnaryPredicate pred)
33 {
34 BOOST_RANGE_CONCEPT_ASSERT(( SinglePassRangeConcept<SinglePassRange> ));
35 return std::count_if(boost::begin(rng), boost::end(rng), pred);
36 }
37
38 /// \overload
39 template< class SinglePassRange, class UnaryPredicate >
40 inline BOOST_DEDUCED_TYPENAME boost::range_difference<const SinglePassRange>::type
count_if(const SinglePassRange & rng,UnaryPredicate pred)41 count_if(const SinglePassRange& rng, UnaryPredicate pred)
42 {
43 BOOST_RANGE_CONCEPT_ASSERT(( SinglePassRangeConcept<const SinglePassRange> ));
44 return std::count_if(boost::begin(rng), boost::end(rng), pred);
45 }
46
47 } // namespace range
48 using range::count_if;
49 } // namespace boost
50
51 #endif // include guard
52