I remember reading that for ($start..$end) kind of loops are also optimized not to produce an intermediate list:
$ perl -s -e'
sub mymem { system("ps -q $$ -o vsz") };
mymem();
$#a = $size;
mymem();
$a[$_]=0 for 0..$#a;
mymem()
' -- -size=1e7
VSZ
18724
VSZ
96852
VSZ
333528
$ perl -s -e'
sub mymem { system("ps -q $$ -o vsz") };
mymem();
$#a = $size;
mymem();
$a[--$size]=0 while $size;
mymem()
' -- -size=1e7
VSZ
18724
VSZ
96852
VSZ
333528
$ perl -E'say $^V'
v5.24.1
At least, they seem to be on my machine.
This doesn't cover map, though:
$ perl -s -e'
sub mymem { system("ps -q $$ -o vsz") };
mymem();
$#a = $size;
mymem();
map {$_} 0..$#a;
mymem()
' -- -size=1e7
VSZ
18724
VSZ
96852
VSZ
573664
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