How to expand the initializer list parameters pack?

Question

Codes like:

template <typename... type>
void print(type... pack) {
    ((std::cout << pack << " "), ...);
}

But I have parameters like: { {1, 2, 3}, {4, 5, 6} }

So how can I pass this to the function ? Or, how to expand the parameters pack like this ?

Answer 1

But I have parameters like: { {1, 2, 3}, {4, 5, 6} }

You can pack them into std::tuples

#include<iostream>
#include<tuple>

template <typename... Tuples>
void print_tuples(Tuples... tuples) {
  (std::apply([](auto... args) {
    ((std::cout << args << " "), ...);
  }, tuples), ...);
}

Then

print_tuples(std::tuple{1, 2, 3}, std::tuple{4, 5, 6});

Demo