How to give template template arguments to class

Vote count:

0

How should I give template template argument(s) to class S below?

#include "tuple"
template<
    class C1,
    template<class... C3> class C2,
    class... C3/*,
    template<class... C5> class C4,
    class... C5*/
> struct S {};
int main() {
    S<
        int,
        std::tuple<int, char>/*,
        std::tuple<double>*/
    > s;
    return 0;
}

GCC 4.8.3 complains:

expected a class template, got 'std::tuple<int, char>'

What should I use instead of tuple? S has to know C3 in its operator() but I can't give C3 there because boost::mpl::for_each expects a specific signature for operator(). Previously I've handled this by giving tuple<int, char>() as a regular argument to deduce the templates but that doesn't seem possible here.

asked 2 mins ago

user1226313

11

How to give template template arguments to class