Where does "U" in Rebindable.Rebindable come from?

[simendsjo]

On Fri, 30 Mar 2012 17:13:25 +0200, Simen Kjærås <simen.kjaras at gmail.com>  
wrote:
>
> Indeed. The thing is - U is basically *set* by the isExpression. It says
> 'yes, there is such a U, so I'll add it to the local scope.'. This means
> that U will be set for the entire scope within which the static if
> exists.
>
> Due to the way the criteria are phrased, U is defined when the criteria
> are not met, and as such are defined in the else clause instead of the
> if clause.
>
>
> { // Outer scope starts here.
>    static if ( !is( const(int) t == const(U), U ) ) {
>      // isExpression returned false, so U is undefined
>    } else {
>      // But here it is defined, because we're still in the same,
>      // broader scope.
>    }
> }
> // And here it's no longer defined.
>
> Was that any better? I admit I didn't understand it at first either, but
> then I remembered that static if does not introduce a new scope. That
> helped.

I knew static if didn't create a new scope, but I still thought U would  
not be defined if it didn't match, but it seems it is defined just by  
existing in the scope.
I had a bug when I tried to reproduce the behavior: I used typeof(U),  
which is, of course, not possible as U is a type :)

Thanks for the explanation. Allowed to use D at work yet btw?