effective way to select last parameter of variadic template

Question

I know how to select first parameter of variadic template:

template< class...Args> struct select_first;
template< class A, class ...Args> struct          


        

Answer 1

Sorry for being a bit late to the party, but I just ran across the same problem , looked up for an answer, didn't like what I see here and realised it can be done using a tuple. Please see C++11 implementation below. Note: one can also get access to an Nth type of a variadic template this way. (The example doesn't check that N exceeds the number of variadic arguments , however the check can be done with SFINAE technique (enable_if) for instance) Is that an acceptable answer or I'm missing anything in the question?

#include 
#include 

struct A
{
    char ch = 'a';
};
struct B
{
    char ch = 'b';
};
struct C
{
    char ch = 'c';
};


template 
struct SomeVariadic {

    using TypesTuple = std::tuple;

    using LastType = typename std::tuple_element::type;

    template 
    using NthType = typename std::tuple_element::type;
};



int main(int argc, char* argv[]) {

    SomeVariadic::LastType l;

    std::cout << SomeVariadic::LastType().ch << " "
            << SomeVariadic::NthType<1>().ch<< std::endl;
}