Updated: to correct my misreading of who I was responding to. dragonchild's sudden interjection into what had been a two person thread caught me out. I apologise to dragonchild for my mis-attributions.

I am not suffering from tunnel vision.

You Someone else brought up the typing system--not I.

I simply explained why typing is no alternative to validation.

You are completly ignoring all the reasons I have outlined why the tie mechanism cannot be used to perform validation.

But, if you wanted to use, say, pre- and post-execution subroutines or Params::Validate or any other scheme...

When? How? Show me an example?

I have, in answer to your previous assertions, shown how the mechanism described for validation of the value assigned won't work. Now you throw this in as if it answers something? It doesn't!

All of the problems outlined still remain unanswered and this throwaway line doesn't even pretend to address them.