Self-Replacing Stub

        sub croak {
          require Carp;
          *croak = \&Carp::croak;
          goto &croak;
        }

• The first time you call this, it replaces itself with the real croak.

• The second time you try to call it, you just get the real croak directly.

• Now just say

        croak("I am not a number.  I am a free man.");

• Alternative:

     use autouse 'Carp' => 'croak';

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Copyright © 2003 M. J. Dominus