[Bug c++/54506] Defaulted move constructors and move assignment operators are erroneously defined as deleted

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54506

--- Comment #4 from Jonathan Wakely <redi at gcc dot gnu.org> 2012-09-09 
21:36:40 UTC ---
The example can be simplified to 

    struct A
    {
        A() {}

        A(A &&) = delete;
        A &operator =(A &&) = delete;
    };

    struct B
    {
        A a;
        B() = default;
    };

    int main()
    {
        B b = B();
        b = B();
    }

I think this is ill-formed, so G++ is right to reject it.

struct A cannot be moved because its move operations are deleted, and cannot be
copied because the implicit-declared copy operations are defined as deleted,
see [class.copy]/7.  Therefore struct B cannot be moved or copied either.