Why shouldn't I use UNIVERSAL::isa?

Question

According to this

http://perldoc.perl.org/UNIVERSAL.html

I shouldn\'t use UNIVERSAL::isa() and should instead use $obj->isa() or CLASS->isa().

This means

Answer 1

Right. It does a wrong thing for classes that overload isa. Just use the following idiom:

if (eval { $obj->isa($class) }) {

It is easily understood and commonly accepted.