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The literal reference is just a value which in your map just happens to be contained in $_. When you reassign 1 to it, it's not changing the reference in any way, you're just putting something else in $_ (although this is where I'm getting fuzzy and agree it's somewhat weird); it's just that $_ just happens to be aliased to some temporary SV* / SVrv that the map is using as its argument list. The assignment isn't changing the referenced value, it's just sticking the new SViv 1 into that SV*.

DB<1> $a = $b = [qw/a b c/] DB<2> x map { $_ = 1 } $a 0 1 DB<3> x $a 0 1 DB<4> x $b 0 ARRAY(0x7fa8144335b0) 0 'a' 1 'b' 2 'c'

Hopefully someone more conversant in perlguts than I might can explain it better.

The cake is a lie.
The cake is a lie.
The cake is a lie.


In reply to Re: Shouldn't references be readonly? by Fletch
in thread Shouldn't LITERAL references be readonly? (updated) by LanX

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