Perl attempts to improve the performance of method invocations by caching the results of method
lookups. These cached results become incorrect when @ISA is alterred
Oh, come on. Please get a newer version of Perl. I reported
this bug in the beginning of 1997, and it was fixed shortly after.
The Camel-II explicitely mentions that modifying @ISA clears the
cache.
You're claiming that modifying @ISA is bad, because it changes
the implementation of the class. But is that always bad?
Installing a sub in an AUTOLOAD also changes the implementation
of a class, and that's something done often.
I wouldn't recommend modifying @ISA, unless you're really
sure what you are doing. But I also won't claim modifying
@ISA should never been done.
Abigail