use strict; use warnings; 
  $|=1; 

  use Scalar::Util qw(dualvar);


use Devel::Peek;
print "nv1\n"; my $nv1 = 1e-2                 ;Dump($nv1); print "nv1:$nv1 ".($nv1+0)."\n"; Dump($nv1); 
print "dv2\n"; my $dv2 = dualvar( 1e-2, "hi" );Dump($dv2); print "dv2:$dv2 ".($dv2+0)."\n"; Dump($dv2);