http://www.perlmonks.org?node_id=1009067


in reply to Re^2: $1 not "freezing" in an addition
in thread $1 not "freezing" in an addition

it seems its a good habit The safest thing you can do is to stringify $1,$2 when you're not doing assignment using them in an lvalue context. 

f("$1")
for ("$1")
\"$1"

[download]

In Section Seekers of Perl Wisdom