Enforce variadic template of certain type

Question

I would like to enforce the type of variadic template to be identical to an earlier set template type. In the below example, I\'d like T and U to be the same type.

c

Answer 1

Without implementing of all_same you could also change the constructor code as follows:

template::value>::type, class... U>
    Foo(F first, U... vals): Foo(vals...) {
    std::cout << "Called multiple argument ctor" << std::endl;
    // [...]   
}

is_same is the function in an STL