use Config;
sub new_from_number {
   my $class = shift;
   my $num = shift;
   my $fmt = '%.0f';
   if (exists($Config{nv_preserves_uv_bits})
      && $Config{nv_preserves_uv_bits} < 8 * $Config{uvsize}
   ) {
      $fmt = $num < 0 ? '%d' : '%u';
   }
   $class->new(sprintf($fmt, $num));
}