perl -MO=Deparse -e " s///g "
perl -MO=Deparse -e " s\\\g "
perl -MO=Deparse -e " s[][]g "
perl -MO=Deparse -e " s()()g "
perl -MO=Deparse -e " s{}{}g "
perl -MO=Deparse -e " s!!!g "
perl -MO=Deparse -e " s###g "
perl -MO=Deparse -e " s vvvg "
perl -MO=Deparse -e " s ___g "
perl -MO=Deparse -e " s {}//g "
perl -MO=Deparse -e " s {}\\g "
perl -MO=Deparse -e " s {}vvg "
perl -MO=Deparse -e " s {}()g "
perl -MO=Deparse -e " s {}[]g "
perl -MO=Deparse -e " s {}<>g "
perl -MO=Deparse -e " s<><>g "

##</code><code>##

s///g;
-e syntax OK
##</code><code>##

$ perl -MO=Deparse -e " s«»«»g "
Substitution replacement not terminated at -e line 1.

$ perl -MO=Deparse -e " s«««g "
s///g;
-e syntax OK