CTFE determination?

[Russell Lewis]

bmeck wrote:
> Hi i was messing around in D2 and noticed that the following always is saying that it is only at runtime even when the input is a constant... was wondering if there was a right way to do this.

CTFE only kicks in when the function is called in a context which 
requires a compile-time constant, such as passing the return value from 
the function as the parameter to a template.

If you don't use the function in that context, then CTFE is *not* 
active.  Thus, your test() function is *not* compile-time evaluated.

The basic reason for this is that if you write a long-running scientific 
program with fixed inputs you don't want CTFE to kick in just because 
the inputs are hard-coded.