Well, I had a look at Math::BigInt source code and it seemed to me that the '*' overloading had already a lot of elsif branches. I just don't want to reinvent the wheel and redo what has already been done. Basically I whish I could just say "if the second operand is a My::Custom::Object then do this, otherwise just do whatever '*' does in the Math::BigInt class".

About explicit blessing, I just don't see how I could do it otherwise, unless I use a constructor anyway. But now that you make me think of it , I wonder if the magic of bigint wouldn't be inherited. I have to check this out, indeed.

You are right about using overloading not being necessary. But it would definitely be cool.