package thisPack;
sub smartish_sub {
  my $self; # for instance reference, if called that way
  my $class; # for classname, if called that way
  if (ref $_[0]) {
     if (UNIVERSAL::isa($self,'thisPack')) {
             # ( corrected from earlier ->isa call)
       # it's an instance method invocation
       my $self = shift @_;
     }
     # else it's not an instance, but it is a ref, so 
     # it must be a fully-qualified invocation
  }
  else {
     # not a reference; ought to be class invocation
     my $class = shift;
     die "first argument to smartsub must be hashref\n"
       unless UNIVERSAL::isa($class, 'thisPack');
  }
  # now any class- or instance- invocations have been 
  # shifted off @_
  my ($hash, $string) = @_; # might want error-checking here.
  print "$hash->{foo}\n$string";
}
sub new {
  bless {}, shift;
}