Sprout/sprout/tuple/fused.hpp
2013-02-08 00:49:47 +09:00

82 lines
2.2 KiB
C++

#ifndef SPROUT_TUPLE_FUSED_HPP
#define SPROUT_TUPLE_FUSED_HPP
#include <utility>
#include <type_traits>
#include <sprout/config.hpp>
#include <sprout/index_tuple.hpp>
#include <sprout/tuple/tuple/tuple.hpp>
#include <sprout/tuple/tuple/get.hpp>
#include <sprout/utility/forward.hpp>
namespace sprout {
namespace tuples {
//
// fused
//
template<typename F>
class fused {
public:
typedef F functor_type;
private:
template<typename Tuple, typename IndexTuple>
struct result_impl;
template<typename Tuple, sprout::index_t... Indexes>
struct result_impl<Tuple, sprout::index_tuple<Indexes...> > {
public:
typedef decltype(
std::declval<functor_type const&>()(
sprout::tuples::get<Indexes>(std::declval<Tuple>())...
)
) type;
};
public:
template<typename Tuple>
struct result
: public result_impl<
Tuple,
typename sprout::index_range<0, sprout::tuples::tuple_size<typename std::remove_reference<Tuple>::type>::value>::type
>
{};
private:
functor_type f_;
private:
template<typename Result, typename Tuple, sprout::index_t... Indexes>
SPROUT_CONSTEXPR Result
call(Tuple&& t, sprout::index_tuple<Indexes...>) const {
return f_(sprout::tuples::get<Indexes>(sprout::forward<Tuple>(t))...);
}
public:
fused() = default;
fused(fused const&) = default;
explicit SPROUT_CONSTEXPR fused(F f)
: f_(f)
{}
SPROUT_CONSTEXPR functor_type functor() const {
return f_;
}
template<typename Tuple>
SPROUT_CONSTEXPR typename result<Tuple>::type
operator()(Tuple&& t) const {
return call<typename result<Tuple>::type>(
sprout::forward<Tuple>(t),
sprout::index_range<0, sprout::tuples::tuple_size<typename std::remove_reference<Tuple>::type>::value>::make()
);
}
};
//
// make_fused
//
template<typename F>
inline SPROUT_CONSTEXPR sprout::tuples::fused<F>
make_fused(F const& f) {
return sprout::tuples::fused<F>(f);
}
} // namespace tuples
using sprout::tuples::fused;
using sprout::tuples::make_fused;
} // namespace sprout
#endif // #ifndef SPROUT_TUPLE_FUSED_HPP