Static override?

[Artur Skawina]

On 04/04/14 11:22, Atila Neves wrote:
>     enum hasAccept(T) = is(typeof(() {
>         auto s = T();
>         auto foo = FooVisitor();
>         s.accept(foo);
>         auto bar = BarVisitor();
>         s.accept(bar);
>     }));
 
> The static asserts are there to verify that the structs I define actually do implement the interface I want them to. Which is great when they work, but tricky to find out why they don't when the assert fails.

    template hasAccept(T) {
       static iface(CT)(CT t) {
          auto foo = FooVisitor();
          t.accept(foo);
          auto bar = BarVisitor();
          t.accept(bar);
       }
       static if (is(typeof(iface!T)))
          enum hasAccept = true;
       else
          enum hasAccept = &iface!T;
    }

[Should probably be split into three parts: 1) the if-definition, 2) the
 does-T-implement-the-if check, and 3) the T-must-implement-the-if assertion.]

artur