For years, I've noticed that there's an use if pragma in Perl. How would I use it?

The Perldoc on it is sort of sparse. What is CONDITION, and how would I set it? Since this is a pragma, it's executed before anything in my code, so I can't use variables or constants as a condition:

use if CONST, Foo::bar;

Is the if pragma used, and if so, how?

In reply to How do you use the if pragma? by qazwart

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