my $selector = sub { $_[0] eq $whatever };

##</code><code>##

my $selector = sub {
                     my($obj)=@_;
                     my $code_ref = overload::Method($obj, "eq");
                     if($code_ref) { # $obj overloads "eq"
                        # call the overloading-implementation
                        return $code_ref->($obj, $whatever); 
                     else {  # no overloading -do something else
                        return $obj eq $whatever;
                     }               
                   };