$ perl -c -we'my %f; my @a = @f{qw( a b )}'
-e syntax OK

$ perl -c -we'my %f; my @a = @f{qw! a b !}'
-e syntax OK

$ perl -c -we'my %f; my @a = @f{qw# a b #}'
Scalar value @f{qw# a b #} better written as $f{qw# a b #} at -e line 1.
-e syntax OK

$ perl -c -we'my %f; my @a = @f{qw$ a b $}'
Scalar value @f{qw$ a b $} better written as $f{qw$ a b $} at -e line 1.
-e syntax OK