How can I get the innermost template parameter type?

Question

Q

In a dummy example of a class

typedef myStruct>> mv;

int is the innermost

Answer 1

Building on 0x499602D2's answer, we get the following to only consider the first template parameter if ever there are several. And yes it compiles. It's also slightly simpler.

#include 
#include 
#include 

template
struct innermost_impl
{
    using type = T;
};

template class E, typename Head, typename... Tail>
struct innermost_impl>
{
    using type = typename innermost_impl::type;
};

template
using innermost = typename innermost_impl::type;

template
struct X;

static_assert(std::is_same>>>, int>::value, "");

static_assert(
    std::is_same>>>, int>::value,
    ""
);

int main()
{
}

Note that no attempt is made to validate that the same template is used over and over.