Win8 Strawberry 5.8.9.5 (32)  Tue 11/24/2020 14:56:16
C:\@Work\Perl\monks
>perl -Mstrict -Mwarnings -l
sub f { return $_[0] = 42; }

my $x = 88;
print f($x);
print   $x;

print f(99);
^Z
42
42
Modification of a read-only value attempted at - line 1.