How can I create a multi dimensional std::array
of type Type
with (of course) known initial constexpr
dimensions with some smart variadic template "MDA".
The number of dimensions shall be variable.
In the end I want to be able to write:
MDA<int,3,4,5,6> a4d{};
and the result should be equal to
std::array < std::array < std::array < std::array<int, 6> , 5 > , 4 > , 3 > a4d{};
And save a lot of (complicated, or even error prone) typing work . . .
Edit:
I am not sure if this possible at all. But what I am looking for, is some "typing saver", maybe in conjunction with a using
statement.
Certainly possible with use of helper class templates, C++11 (except the static assert part)
#include <array>
template<typename T, std::size_t Head, std::size_t... Tail>
struct MDA_impl{
using type = std::array<typename MDA_impl<T, Tail...>::type, Head>;
};
// Base specialization
template<typename T, std::size_t N>
struct MDA_impl<T,N>{
using type = std::array<T, N>;
};
template<typename T, std::size_t... Ns>
using MDA = typename MDA_impl<T,Ns...>::type;
int main(){
static_assert(std::is_same_v<MDA<int,3,4,5,6>,
std::array<std::array<std::array<std::array<int, 6>,5>,4>,3>>);
}