in reply to
I've taken the comments pointing out methods of getting around the apparent limits on multiple actions in a one-line if statement to heart and inserted a brief mention into the text of if variants. Rather than actually attempt to comprehensively list and explain them all, adding cruft to what may already be a too-bloated treatment of if statement variants, I have simply made brief mention of the fact and left it at that.
I think it would be helpful and useful, and generally a good idea, if someone were to create a new node on the topic of such exceptions to that limitation of one-line conditionals. If the author of such a thing messages me after creating that node, I'll have a look at it and consider linking to it from the text of this node (assuming it's sufficiently relevant and clearly written).
Or, I might write it myself if nobody else does, eventually. I'm not a Perl guru, however, and that might be some time in coming.