This is Perl, not Ruby. Methods are subs in a given package, not properties of individual instances. You possibly could do some dark magic with AUTOLOAD (make it lookup say $self->{_instancemethods}->{$AUTOLOAD} and call that if it exists), or eval new code into the instance's package (eval qq{ package @{[ ref $self ]}; sub { "NEW CODE" }}; however that's going to make the method available on all instances of that class (and its descendants) not just the one in $self)).

Perhaps you could elaborate on what you're trying to do and you might get better suggestions (e.g. yes, you're trying to emulate Ruby's 

class << obj
  def new_method
   "fweeee"
  end
end

[download]
in order to add a method on a single instance).

Update: Formatting and wording tweaks.

In reply to Re: on the fly methods by Fletch
in thread on the fly methods by Ojosh!ro

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