Sprout/sprout/tuple/operation/push_front.hpp
2011-11-04 02:11:19 +09:00

70 lines
1.9 KiB
C++

#ifndef SPROUT_TUPLE_OPERATION_PUSH_FRONT_HPP
#define SPROUT_TUPLE_OPERATION_PUSH_FRONT_HPP
#include <cstddef>
#include <sprout/config.hpp>
#include <sprout/index_tuple.hpp>
#include <sprout/tuple/traits.hpp>
#include <sprout/tuple/functions.hpp>
namespace sprout {
namespace tuples {
namespace result_of {
//
// push_front
//
template<typename Tuple, typename T>
struct push_front {
private:
template<typename IndexTuple>
struct apply_impl;
template<std::ptrdiff_t... Indexes>
struct apply_impl<sprout::index_tuple<Indexes...>>
: public sprout::tuples::rebind_types<
Tuple
>::template apply<
T,
typename sprout::tuples::tuple_element<Indexes, Tuple>::type...
>
{};
public:
typedef typename apply_impl<
typename sprout::index_range<0, sprout::tuples::tuple_size<Tuple>::value>::type
>::type type;
};
} // namespace result_of
namespace detail {
template<typename Result, typename Tuple, typename T, std::ptrdiff_t... Indexes>
SPROUT_CONSTEXPR inline Result push_front_impl(
Tuple const& t,
T const& v,
sprout::index_tuple<Indexes...>
)
{
return sprout::tuples::remake_clone<Result>(
t,
v,
sprout::tuples::get<Indexes>(t)...
);
}
} // namespace detail
//
// push_front
//
template<typename Tuple, typename T>
SPROUT_CONSTEXPR inline typename sprout::tuples::result_of::push_front<Tuple, T>::type push_front(
Tuple const& t,
T const& v
)
{
return sprout::tuples::detail::push_front_impl<typename sprout::tuples::result_of::push_front<Tuple, T>::type>(
t,
v,
typename sprout::index_range<0, sprout::tuples::tuple_size<Tuple>::value>::type()
);
}
} // namespace tuples
} // namespace sprout
#endif // #ifndef SPROUT_TUPLE_OPERATION_PUSH_FRONT_HPP