; sub capture (&;*)
   { my $code = shift
   ; my $fh   = shift || select
   ; local $output     
   ; no strict 'refs'
   ; if ( my $to = tied *$fh )
      { my $tc = ref $to
      ; bless $to, __PACKAGE__
      ; &{$code}()
      ; bless $to, $tc
      }
     else
      { tie *$fh , __PACKAGE__
      ; &{$code}()
      ; untie *$fh
      }
   ; \$output
   }