The general part of the question (how to recognize other data structures that mirror data) is hard.

But causing one reference to a data structure to be the same as another is fairly easy: 

sub some_sub {
  $_[0] = $bar;
}

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The trick is that while variables are in @_ they are passed in by reference. If you don't make copies, then you can modify the passed in values. This API may surprise...

In reply to Re: Re: Re: How to change referent of lexical reference? by tilly
in thread How to change referent of lexical reference? by autarch

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