computing ceil at compile time

[bearophile]

bioinfornatics:

> $ ldc2 compute.d main.d -of ok
> /usr/include/d/std/math.d(2471): Error: ceill cannot be 
> interpreted at compile time, because it has no available source 
> code
> compute.d(5):        called from here: ceil(cast(real)i)
> compute.d(8):        called from here: foo(2.4F)

At the moment some std.math functions that deal with floating 
point numbers can't be run at compile-time.

Bye,
bearophile