sub foo {}

foo(@foo{qw/a b/});
print keys %foo; # ab

##</code><code>##

use warnings;
sub context { defined $_[0] ? $_[0] ? 'list' : 'scalar' : 'void' }
sub foo :lvalue { print context(wantarray); my $dummy = '' }
sub bar :lvalue { print context(wantarray); my $dummy = '' }

my $baz;
($baz, foo(), bar()) x= 3;

__END__
Useless use of private variable in void context
void
scalar