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?

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.

Fail.
Ok, i tried something like this:
[code]
import std.stdio;

mixin template TConvertTo(T : Object,  U) {
	T!(U) ConvertTo() inout {
		return cast(T!U) this;
	}
	
	alias ConvertTo this;
}

class Foo(T) {
public:
	T Num;
	
	mixin TConvertTo!(typeof(this), float);
	
}
[/code]

but it fails with:
template_alias_this_cast.d(4): Error: template instance T!(float) T is not a template declaration, it is a class
template_alias_this_cast.d(4): Error: T!(float) is used as a type
template_alias_this_cast.d(15): Error: mixin template_alias_this_cast.Foo!(float).Foo.TConvertTo!(Foo,float) error instantiating
template_alias_this_cast.d(19): Error: template instance template_alias_this_cast.Foo!(float) error instantiating

If i change it to:
[code]
import std.stdio;

mixin template TConvertTo(V) {
	Foo!(V) ConvertTo() inout {
		return cast(Foo!V) this;
	}
	
	alias ConvertTo this;
}

class Foo(T) {
public:
	T Num;
	
	mixin TConvertTo!(float);
	
}
[/code]

it works. But i think my first idea should work, too.