What is a practical use-case for `#defined`?

General
1

As title says.

Tbh I can think of a few use-cases (such as ‘optional extensibility’ where you could create a few functions with specific names and the source code can pick up on that, but this isn’t working working atm. Whenever I check when #defined(otherpkg.procedure_that_exists) { } on a proc in a different package, it always returns false.

Is this only allowed for same package?

2

It’s mostly for bodges. As much as that pains me to say, but exists for that reason. It’s a pragmatic rationale for the rare edge-cases and not necessarily something you should ever use if have the option to never use it.