Re: alias this with template class?

[Timon Gehr]

On 06/03/2012 08:43 PM, Namespace wrote:

I think this should work:

[code]
import std.stdio;

class Foo(T) {
public:
     T Num;

     @property
     Foo!(U) ConvertTo(U)() inout {
         return cast(Foo!(U)) this;
     }

     alias ConvertTo this;
}

void Call(const Foo!(float) FFoo) {

}

void main() {
     Foo!(ubyte) UbFoo = new Foo!(ubyte)();

     Call(UbFoo);

     readln();
}
[/code]

Why it doesn't?

Making this generally work as you expect would be too hard.
The compiler would have to reverse-engineer the 'ConvertTo' template
which is an undecidable problem in general. Some clever heuristics
might suffice for most practical instances though, but those are
very open-ended and therefore it is hard to incorporate them into the
language definition. If you think it should be done you could file a
suggestion (enhancement request) into the bug tracker.