Extend the call site default argument expansion mechanism?

[jmh530]

On Wednesday, 16 May 2018 at 09:01:29 UTC, Simen Kjærås wrote:
> snip]
>
>     struct Foo(int x)
>     {
>         int n = x;
>         auto opDispatch(string s)()
>             if (s == "bar")
>         {
>             n++;
>             return n;
>         }
>     }
>
>
>     unittest
>     {
>         int y = 0;
>         with(Foo!1())
>         {
>             y = bar; // Works!
>         }
>         assert(y == 2);
>     }
>
> --
>   Simen

Thanks for catching that. Any idea why the original was having 
problems?