How do I make object methods callable as non-OO functions?

trammell has asked for the wisdom of the Perl Monks concerning the following question: ⭐ (object-oriented programming)

For example, say I have a class 'Foo' that is used thusly:

  use Foo;
  my $f = Foo->new(%args);
  my $g = $f->frobnicate;
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but for some Very Good Reason, we want to be able to call it in a more procedural fashion:

  use Foo 'frobnicate';
  my $g = frobnicate($args);
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Is there a good way of doing this? Is there a good reason not to do this?

Originally posted as a Categorized Question.