CTFE attribute

[Robert Clipsham]

On 28/01/2012 14:50, Manu wrote:
> This has come up lots of times before.. I just wanted to effectively +1
> this request.
>
> I have some templates, and some reasonably complex functions I use
> strictly via CTFE to produce enums and evaluate conditions within the
> templates.
> When I build my code, I notice that the CTFE functions, which are never
> referenced in any runtime code, are still present in the object file.
> Additionally, one of these functions requires I import std.string, which
> is only used in CTFE code, and is otherwise a pointless import.
>
> I'd certainly like to be able to mark these functions CTFE to be sure no
> runtime code will ever be generated for them, and also, what can I do
> about CTFE imports? I don't want that import in my binary...

There are a couple of things you can do. The first is to make the 
imports function local, the second is:

http://www.digitalmars.com/d/archives/digitalmars/D/Incremental_compilation_with_DMD_96138.html#N96337

You'll notice that thread mentions a pragma(ctfe) patch for DMD, that's 
another option, though would require a patched compiler. I can't seem to 
find a link to that patch, a bit of googling should help though.

Another idea I've just had:

T myComplexFuntion()
{
   if (__ctfe)
   {
      // Implement here
   }
   else
   {
     assert(0);
   }
}

This should allow the function to be inlined to assert(0); if it's 
called at runtime, so while it will still exist in the binary, it won't 
introduce lots of additional bloat.

-- 
Robert
http://octarineparrot.com/