Refactoring

The first time you're tempted to copy-paste-and-modify a piece of code:

package Process::Queue;
use Carp;
{
    use overload (
        # Type coercions don't make sense for process queues...
        q{""}   => sub {
            croak q{Can't stringify a Process::Queue};
        },
        q{0+}   => sub {
            croak q{Can't numerify a Process::Queue };
        },
        q{bool} => sub {
            croak q{Can't get the boolean value of a Process::Queue };
        },
    );
}
# and later...

package Socket;
use Carp;
{
    use overload (
        # Type coercions don't make sense for sockets...
        q{""}   => sub {
            croak q{Can't convert a Socket to a string};
        },
        q{0+}   => sub {
            croak q{Can't convert a Socket to a number};
        },
        q{bool} => sub {
            croak q{Can't get the boolean value of a Socket };
        },
    );
}