http://www.perlmonks.org?node_id=304505


in reply to When -w and use strict aren't enough...

Even if there wasn't AUTOLOAD and eval, perl's loose typing makes it impossible to check method names at compile time. Consider this snippet: 
sub foo{
  my $thing = shift;
  print $thing->to_xml;
}

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$thing could be anything, there is no way at compile time for perl to know if $thing has a "to_xml" method

In Section Seekers of Perl Wisdom