Jarrett Billingsley wrote:
version(TurnOffSomeFeature) {} else
{
codeForFeature();
}
Sometimes you want to have things that turn _off_ code from a default
of being on.
I know, I know, Walter said that "[v]ersions should be positive
things, because a version is something that is being build - one
doesn't craft a makefile to build a notLinux." But the fact is,
platform-specific stuff and code options are two very different use
cases. Platform-specific things are completely invisible to the user
of a library and only one configuration can ever be in use on a single
platform. Code options, on the other hand, are based on user
preference. Some things are extra, and it makes sense to have
switches to turn them on. But some things are the other way, where
you want them *on* by default and want to have the option of turning
them *off*.
Even if a feature is on by default, versions should still be a positive
thing, otherwise you have a double negative:
version (!TurnOffSomeFeature)
Even in regular code, I try to avoid naming things that way, because
double negatives are twice as hard to comprehend when things get
complicated. I've gone through my code to remove such double negatives
as much as possible.
So I suggest:
version (SomeFeature)
{
codeForFeature();
}
is clearer, even if SomeFeature is the default.
