Listing 4: Unary + and -

UDouble::UDouble<is_correlated>  operator  +(void)  const
{  return  *this;  }
UDouble::UDouble<is_correlated>  operator  -(void)  const
{
   if  (is_correlated)
       return  UDouble<is_correlated>(-value,  -uncertainty);
   else
       return  UDouble<is_correlated>(-value,  uncertainty);
}
//End of File