Would it be reasonable for me to expect perl, in the first case, to emit a warning. Say something like "Probably useless use of a constant in grep block"?

Sure its reasonable, but then lots of things are reasonable :)

How often would you make this error? How often would you not notice that @ary didn't get filtered? Average programmer?

I think

rarely * rarely * rarely = warning unimportant

Also, "Probably" doesn't really belong in warnings :) it means this shouldn't be a warning

In reply to Re: "Useless use of a constant" in grep block? by Anonymous Monk
in thread "Useless use of a constant" in grep block? by perlancar

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