Dlang equivalent of #define/#ifdef : not... version

[Steven Schveighoffer]

On 4/21/21 2:38 AM, Dukc wrote:
> On Tuesday, 20 April 2021 at 23:58:46 UTC, Steven Schveighoffer wrote:
>> static if(i_am_a_feature) {
>>    ...
>> }
> This would be correct if `i_am_a_feature` would be always defined, just 
> set to `false` if not existent. But I think the idea was to not define 
> the symbol at all if feature does not exists. In that case, the 
> condition should be `static if(is(typeof(i_am_a_feature)))`.

Yeah, you're right. It's different than ifdef.

I think version is the closest thing.

Note that you can convert versions into enums via:

version(define_the_thing)
{
    enum the_thing_is_defined = 1;
}
else
{
    enum the_thing_is_defined = 0;
}

-Steve