Andrej Mitrovic wrote:
> I think this is relevant:
> http://www.digitalmars.com/d/2.0/template.html : "Limitations":
>
> Templates cannot be used to add non-static members or virtual
> functions to classes.
> Templates cannot add functions to interfaces.
>
> But I'm a little confused as to how it all works out. This will work:
>
> import std.stdio;
>
> class Foo
> {
> void draw(T)(T t) { writeln("Foo"); };
> }
>
> class Bar : Foo
> {
> /* override */ void draw(T)(T t) { writeln("Bar"); };
> }
Bar.draw does not override, but "hide" Foo.draw. They are unrelated
functions.
> void main()
> {
> Bar bar = new Bar();
> bar.draw(1); // "Bar"
Bar.draw!int is called. No virtual dispatch is involved, as Foo.draw!int
doesn't even exist.
> (cast(Foo)bar).draw(1); // "Foo"
Now Foo.draw!int is instantiated (at compile time) an is called. There
is no Bar.draw!int instantiated at all.
> }
>
> But uncomment the override and it fails.
That's because "Templates cannot be used to add [...] virtual functions
to classes"
Ali
