Sprout/sprout/detail/algorithm/count_n_if.hpp
bolero-MURAKAMI f9d4b475b4 add sprout/numeric/dft.wave.hpp
fix constexpr -> inline constexpr
2012-07-15 16:04:05 +09:00

27 lines
736 B
C++

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