Cannot alias expression

[Timon Gehr]

On 10/21/2013 02:58 PM, John Colvin wrote:
> I suspect I'm being very dumb here, but I can't get my head around this:
>
>      template B(alias A)
>      {
>      alias B = A;
>      }
>      template C(A ...)
>      {
>      alias C = A[0];
>      }
>      static assert(B!1 == 1); //fine
>      static assert(C!1 == 1); //Error: cannot alias an expression 1

It is awkward design. I think it should just work. In case you needed to 
this for anything, the following works:

template ID(alias a){ alias ID = a; } // "identity function on symbols"

template B(alias A){
     alias B = A;
}
template C(A ...){
     alias C = ID!(A[0]);
}
static assert(B!1 == 1); // fine
static assert(C!1 == 1); // fine