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#ifndef TYPEASVALUE_SRC_LIST_OPERATION_BASIC_H_
#define TYPEASVALUE_SRC_LIST_OPERATION_BASIC_H_
#include "operation/math.h"
#include "higher/fold.h"
namespace tav {
template <typename Cons>
class Length {
private:
template <
typename,
typename Previous
>
struct count {
typedef Add<Size<1>, Previous> type;
};
public:
typedef typename Fold<count, Size<0>, Cons>::type type;
};
template <
typename Index,
typename Cons
>
struct Nth {
typedef typename Nth<
Substract<Index, Size<1>>,
Tail<Cons>
>::type type;
};
template <typename Index>
struct Nth<Index, void> {
typedef void type;
};
template <typename Cons>
struct Nth<Size<0>, Cons> {
typedef Head<Cons> type;
};
template <
typename Count,
typename Current
>
struct Take {
typedef Cons<
Head<Current>,
typename Take<
Substract<Count, Size<1>>,
Tail<Current>
>::type
> type;
};
template <typename Current>
struct Take<Size<0>, Current> {
typedef void type;
};
template <typename Count>
struct Take<Count, void> {
typedef void type;
};
template <>
struct Take<Size<0>, void> {
typedef void type;
};
}
#endif // TYPEASVALUE_SRC_LIST_OPERATION_BASIC_H_
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