#! perl -slw
use strict;

sub good{ 0 }
sub bad{ 1 }

sub assert {
    return unless $_[ 0 ];
    die join( ' : ', caller, $_[ 1 ] ) . "\n";
}

assert good(), 'Good() produced an error';
assert bad(),  'Bad() produced an error';

__END__
C:\test>junk5
main : C:\test\junk5.pl : 13 : Bad() produced an error