Compile-time reflection

[Fawzi Mohamed]

I understand the need of reflection t connect D to other languages.
Still I think that a solution to this problem should be (not 
necessarily now, but in the future) extensible to template functions.

The virtual/final/static attributes seem quite straightforward and 
unproblematic (I like the is(x==virtual) solution because it is what I 
would have expected).
The symbol+signature -> function pointer is also unproblematic (be it 
through an alias cast or assignment).
The symbol -> signatures thing can be problematic if templates enter in 
the picture.

One could think of representing all kind of signatures by allowing things like
template(TemplateType T0){template(alias T1){template(int 
T2){template(int T3){T0 function(T0[T2],optional T0[T3])}
or something like it.
Unfortunately this is not enough as there is no guarantee that a given 
template is instantiable.
Instantiability can be controlled at compile time, but still for 
automatic interface generators one cannot avoid giving them some extra 
information.

One could think about giving restricting the list of signatures either 
to full specializations (and maybe have some hint that extra ones might 
exist), or to the templates that have been instantiated (but such a set 
is not fixed and can change from program to program).

In any case some thought should be spent about this.

Fawzi