What's wrong with D's templates?

[BCS]

Hello dsimcha,

> Since generics work by basically casting stuff to Object (possibly
> boxing it) and casting back, I wonder if it would be easy to implement
> generics on top of templates through a minimal wrapper.

How about this?

interface Foo { int I(int); }

class CFoo(T) : Foo
{
    T t;
    int I(int i){ return t.I(i); }
}

class CollectionOfFoos_Base(T)
{
    protected:
        Foo opIndex_(int i){ ... }
        Foo opIndex_(int i, Foo f){ ... }
}
class CollectionOfFoos(T) : CollectionOfFoos_Base
{
    public
        T opIndex(int i){ return (cast(CFoo!(T))opIndex(i)).t; }
        T opIndex(int i, Foo f)
        {
           auto b = new CFoo!(T);
           b.t = f;
           return (cast(CFoo!(T))opIndex(i,b)).t;
        }
}

Add opDispatch and it might get even better.