如何制作递归编译时可变参数结构模板

Question

Im trying to make a variadic template in c++ to create a static(non-dynamic allocation) struct defined by arguments of a template.

I tried to google that during 3 days but I think the documentation and my ability to formulate my queries ends here.

This what im trying to go for:

myTemplate<1,5,2,8> myinstance;

myInstance would give me this:

myinstance { int[1], int[5], int[2], int[8] };

So how can you achive this, using variadic template in c++ ? I know already about partial specialisation and that kind of stuff but the documentation is lacking in term of recursion.

Thanks.

Answer 1

You can use std::tuple :

#include <tuple>
#include <array>

template<std::size_t... ns>
struct foo {
    std::tuple<std::array<int, ns>...> contents;
};

foo<1, 5, 2, 8> my_foo;

int main() {
    std::get<1>(my_foo.contents)[3] = 4;
}