Are you saying that if I eval { die MyExceptionClass->new(...) }; that the $@ variable will contain the instance of MyExceptionClass?
Exactly ;-) From perldoc die:
die() can also be called with a reference argument. If this
happens to be trapped within an eval(), $@ contains the
reference. This behavior permits a more elaborate exception
handling implementation using objects that maintain arbitrary
state about the nature of the exception. Such a scheme is
sometimes preferable to matching particular string values of $@
using regular expressions.