Sprout/sprout/index_tuple.hpp
2012-01-09 21:32:51 +09:00

59 lines
1.2 KiB
C++

#ifndef SPROUT_INDEX_TUPLE_HPP
#define SPROUT_INDEX_TUPLE_HPP
#include <cstddef>
#include <sprout/config.hpp>
namespace sprout {
//
// index_tuple
//
template<std::ptrdiff_t... Indexes>
struct index_tuple {};
//
// index_range
//
template<
std::ptrdiff_t First,
std::ptrdiff_t Last,
std::ptrdiff_t Step = 1,
typename Acc = sprout::index_tuple<>,
bool Break = (First >= Last)
>
struct index_range {
typedef Acc type;
};
template<
std::ptrdiff_t First,
std::ptrdiff_t Last,
std::ptrdiff_t Step,
std::ptrdiff_t... Indexes
>
struct index_range<First, Last, Step, sprout::index_tuple<Indexes...>, false>
: public sprout::index_range<First + Step, Last, Step, sprout::index_tuple<Indexes..., First> >
{};
//
// index_n
//
template<
std::ptrdiff_t I,
std::ptrdiff_t N,
typename Acc = sprout::index_tuple<>,
bool Break = (N == 0)
>
struct index_n {
typedef Acc type;
};
template<
std::ptrdiff_t I,
std::ptrdiff_t N,
std::ptrdiff_t... Indexes
>
struct index_n<I, N, sprout::index_tuple<Indexes...>, false>
: public sprout::index_n<I, N - 1, sprout::index_tuple<Indexes..., I> >
{};
} // namespace sprout
#endif // #ifndef SPROUT_INDEX_TUPLE_HPP