I don't know about Strawberry, but in vanilla perl 5.10.0 you can use smart matching without any use feature directive. This was wrongly documented in older development versions, but should be fixed now. (If it isn't, please tell us where you read that).

$ perl5.10.0 --version

This is perl, v5.10.0 built for i486-linux-gnu-thread-multi
[...]
$ perl5.10.0 -wle 'print "YaY" if "a" ~~ m/./'
YaY
[download]

Update: I found the doc patch that fixed perlsyn.