http://www.perlmonks.org?node_id=280053


in reply to Re: Re: Clawing my way out of operator overloading hell
in thread Clawing my way out of operator overloading hell

While the string eq operator can check for reference equivalence, the numeric == operator is preferred for this sort of check.

Sure. It is much more efficient. I only intended to let the OP know that the code he is maintaining might be doing something useful without operator overloading. (It turns out that I guessed right.)

By using the == instead of eq, you compare the addresses directly, rather than converting both operands to strings which happen to include identical character sequences.

Well, I wouldn't go as far as to say stringified references just "happen to include identical character sequences." They include identical character sequences because the same code produces those characters from the same input data.

They're functionally equivalent today, but I imagine someone may find some odd exploit involving stringified references.

An exploit? I would love to hear more about how you think someone might accomplish that. :-)

Yes, == is better than eq for checking reference equality. It's much faster. Use numerical comparison. Tell others to use numerical comparison. But, there is no reason to be paranoid about the construct. It isn't dangerous. It isn't deprecated. (afaik) It works fine; it's just slow.

P.S. I can even think of one good reason to use it. What if you have overridden '0+' and want to check for reference equality rather than the equality of two objects' overridden numification?

-sauoq
"My two cents aren't worth a dime.";