The reason I wrote it that way is that ref($obj) is a single-opcode operation, much less expensive than the execution of UNIVERSAL::isa($obj, 'UNIVERSAL'). Unless you know for certain that the value being tested will a reference the majority of the time, then you can save a reasonable amount of execution time with ref() coupled with the short-circuiting and operator. I stand behind this one.

--rjray

That's a fair statement. It's always good to be efficient whenever it doesn't hurt readability. However, if you're optimizing for speed over readability, I feel that you're going to have problems.

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We are the carpenters and bricklayers of the Information Age.

Don't go borrowing trouble. For programmers, this means Worry only about what you need to implement.