[Kc] subtle distinction that looks like a bug

David Nicol davidnicol at gmail.com
Tue May 3 10:34:19 PDT 2011

with 5.12, also with 5.10 and presumably earlier too:

>perl -le 'sub Q{@_[0,1,2] = (7,6,5)}; Q($a,$b,$c); print qq[$a $b $c\n];'
7 6 5
>perl -le 'sub Q{@_ = (7,6,5)}; Q($a,$b,$c); print qq[$a $b $c\n];'


I was trying to have a subroutine that resets the variables passed to
it when it is called; the second line is the approach I took, it
didn't work. The first approach works though. It appears that in the
second one, we're assigning to a fresh array variable, the old one's
contents having first been jettisoned, instead of overwriting the
elements therein.

The massive headaches that would ensue if my initial approach did what
I wanted are easy to imagine. Or are they? When an array variable
holds copies instead of aliases, as they usually do, there would be

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