std::get using enum class as template argument

Question

I\'m using a std::tuple and defined a class enum to somehow \"naming\" each of the tuple\'s fields, forgetting about their actual indexes.

So instead o

Answer 1

I'd like to add another answer because the original poster asked for a way to have a named access to elements of std::tuple through a class enum.

It is possible to have a template argument of the type of a class enum (at least in GCC). This makes it possible to define your own get retrieving the element of a tuple given a class enum value. Below is an implementation casting this value to int, but you could also do something more fancy:

#include 

enum class names { A = 0, B, C };

template< names n, class... Types >
typename std::tuple_element( n ), std::tuple >::type&
    get( std::tuple& t )
{
    return std::get< static_cast< std::size_t >( n ), Types... >( t );
}

int main( int, char** )
{
    std::tuple< char, char, char > t( 'a', 'b', 'c' );
    char c = get( t );
}

Note that std::get has two more variants (one for const tuple&, one for tuple&&), which can be implemented exactly the same way.