Re: Compile-time evaluation of real expressions?

[Alex Rønne Petersen]

On 06-01-2012 23:21, H. S. Teoh wrote:
Hi All,
As I understand it, compile-time execution *should* be able to evaluate
floating-point functions, correct? Currently, I have this code:

         private static real cross_angles[6] = [
                 real.nan,
                 real.nan,
                 real.nan,
                 atan(sqrt(5)),
                 PI_4,
                 atan(sqrt(5)-2)
         ];

But the compiler is complaining:

/mnt/1/usr/include/d2/4.6/std/math.d:623: Error: asm statements cannot be 
interpreted at compile time
/mnt/1/usr/include/d2/4.6/std/math.d:591: Error: cannot evaluate 
atan2(x,1.0e+0L) at compile time

Is this an artifact of using gdc-4.6 instead of dmd? Or are certain
floating-point functions not allowed in compile-time expressions?

Thanks!

P.S. I just starting learning and using D recently -- and totally loving
it.


T


Most likely those functions are just implemented using inline assembly, 
therefore not usable in CTFE.

--
- Alex