C++11 in gcc 4.8.1: list-initialization for copy constructor doesn't work

Question

I encourages with this problem: If I have

class A
{
public:
};
int main()
{
   A a{};
   A b{a};
}

gcc gives:

moves.

Answer 1

The class is an aggregate, so list-initialisation will perform aggregate initialisation, and won't consider the implicitly-declared constructors.

Since there are no data members, only an empty list can be a valid aggregate initialiser.

But when I use A b(a) instead of A b{a} all compiles correctly.

Direct initialisation will use the implicit constructor rather than attempting aggregate initialisation.

And if I declare default constructor it compiles too.

By declaring a constructor, the class is no longer an aggregate, and can only be initialised using a constructor.