On 01-10-2012 07:40, Tommi wrote:
import std.stdio;
int pow2(int val) pure
{
if (__ctfe)
return 6;
else
return val * val;
}
void main()
{
assert(pow2(3) == 9);
static assert(pow2(3) == 6);
writeln("9 = 6 ... I knew it! '6' was faking it all along");
readln();
}
This is a corner case.
__ctfe is there to allow special-cased CTFE code when absolutely
necessary. By necessity, this separates a function into two worlds:
compile time and run time.
As far as purity goes, pow2 *is* pure. It just does something different
depending on whether you run it at compile time or run time. I don't see
this as a problem in practice.
--
Alex Rønne Petersen
a...@lycus.org
http://lycus.org
