Maybe Q needs to also inherit from P? You can't make assumptions about peer classes. If Q is related to P, then this should be stated in Q's @ISA. If this is not satisfactory, then maybe Q needs to delegate to P in which case the relationship is by composition but this would require some changes to your class hierarchy.

---
print map { my ($m)=1<<hex($_)&11?' ':'';
$m.=substr('AHJPacehklnorstu',hex($_),1) }
split //,'2fde0abe76c36c914586c';
[download]