Semantics of mixed CT and RT statements

[Timoses]

On Sunday, 23 December 2018 at 02:58:30 UTC, Neia Neutuladh wrote:
>
> An optimizer can very easily optimize this:
>
>     // T is SomeType
>     if (is(T == SomeType) || b) doStuff;
>
> to remove the if statement. So from that perspective, no need 
> to worry about it.

Good point. I guess that eliminates the need for something like 
"static if (T) || if (b)".
However, going along that line, why does D even have "static if"? 
We could simply use "if" everywhere and let the compiler take 
care of it. Perhaps it's more a question of expressiveness.


> The sticky bit is that a runtime check needs both paths to 
> typecheck, so if you're mixing metaprogramming with runtime 
> logic, some cases might be weird.

Do you have an example? I'm not quite sure I get what you mean.

>
> I've never needed to do that.