Are interfaces supported in Better C mode?

[Dibyendu Majumdar]

Reading the docs on Better C mode I got the impression that it 
should be possible to implement an interface in a struct. Is this 
not the case?

I tried extern (C++) too, but I get an error.

extern (C++) interface A {
     void sayHello();
}

extern (C++) struct B : A {

}