Sprout/sprout/detail/algorithm/count_n.hpp
2012-10-06 00:58:56 +09:00

23 lines
696 B
C++

#ifndef SPROUT_DETAIL_ALGORITHM_COUNT_N_HPP
#define SPROUT_DETAIL_ALGORITHM_COUNT_N_HPP
#include <iterator>
#include <sprout/config.hpp>
#include <sprout/iterator/operation.hpp>
namespace sprout {
namespace detail {
//
// count_n
//
template<typename InputIterator, typename Size, typename T>
inline SPROUT_CONSTEXPR typename std::iterator_traits<InputIterator>::difference_type
count_n(InputIterator first, Size n, T const& value) {
return n == 0 ? 0
: (*first == value ? 1 : 0) + sprout::detail::count_n(sprout::next(first), n - 1, value)
;
}
} // namespace detail
} // namespace sprout
#endif // #ifndef SPROUT_DETAIL_ALGORITHM_COUNT_N_HPP