And these 'subtle scoping issues' render the output of Deparse incorrect:

$ perl -MO=Deparse -e '@$_{1,2,3}=(4,5,6) for \my %hash;print keys %ha
+sh'
foreach $_ (\my(%hash)) {
    @$_{1, 2, 3} = (4, 5, 6);
}
print keys %hash;
-e syntax OK
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Thus, people who try to understand it via the Deparsed version may be somewhat disappointed.

-- Randal L. Schwartz, Perl hacker

The purpose of the loop is to initialize a hash that he wants to be available afterwards. If the scoping changes then he has initialized a private hash that disappears before he ever gets a chance to use it. Oops...

strict would catch this change.

But then there must be a block for my. But the expression behind for could be arbitrarily complicated and must be evaluated in a wider context. Then there is an equivalency to map to maintain.

map {@$_{@keys}=@values}\my%hash;
[download]

and when were functionarguments a block?