SFINAE check for operator+=

Question

I\'m trying to eliminate an overload from an overload set if operator+= is missing.

I know how to check if T+T is legal :

t         


        

Answer 1

How about this? it's the method used before std::declval.

template())>
void foo(T a, T b, ...)
{
  a += b;
  std::cout << "foo with +=" << std::endl;
}