Good try, but: 
die "Gotcha!" if validate_integer("not an integer");

[download]
Personally I either wouldn't have the test, or else I would make the test be an RE pattern. eg: 
sub is_integer {
  $_[0] =~ /^-?\d+\z/;
}

[download]

In reply to Re (tilly) 2: An example of programming by contract by tilly
in thread An example of programming by contract by princepawn

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