Advent of D

[Steven Schveighoffer]

On 3/7/18 3:20 AM, Andrea Fontana wrote:
> On Tuesday, 6 March 2018 at 20:37:34 UTC, Steven Schveighoffer wrote:
>> What triggers the compile-time execution is the fact that static 
>> *initializers* need to be decided at compile time.
>>
>> So while it is executing the regex building at compile time in your 
>> example, there are other ways to do it, and in this case, I'd prefer 
>> using an enum. You can also use ctRegex.
>>
>> The drawback of using static is that it keeps its value between 
>> function calls:
> 
> What about static immutable? I think enums exist only for compiler but 
> they're not a l-value, so you can't take a reference, am I wrong?

Static immutable works (and makes sense as a static variable) if you can 
use it as immutable. I'm not sure regex can do that.

enums force the compile time execution, then you need to generate a 
runtime value from the result. i.e.:

enum Xval = someCTFEfunction(); // run at CTFE.
auto x = Xval; // no calls, just pastes the result there.

-Steve