If you are expecting a reference I would not recommend using UNIVERSAL::isa this way because the next one who has to deal with your code could believe that there is an object called 'HASH'. (Although this seems not to be very likely but I've seen worse things... :/ ).
If you want to check a reference I would advise you to keep using ref().

In reply to Re^2: Do not use UNIVERSAL::isa this way; but why? by klekker
in thread Do not use UNIVERSAL::isa this way; but why? by klekker

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