Sprout/sprout/detail/count_n.hpp
2012-06-23 13:22:50 +09:00

27 lines
677 B
C++

#ifndef SPROUT_DETAIL_COUNT_N_HPP
#define SPROUT_DETAIL_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>
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_COUNT_N_HPP