Class casting to a type

Question

Anybody know how to implement a casting rule in C++ for one class?

Let's say I have a class Mark that has a double-type member. And I want this class to be cast-able to double:

Mark m(9);
double d = (double)m;

Is it possible to do this?

Answer 1

You can have operator double() inside your class. For example

class Mark
{
     //...
public:
     operator double()
     {
         return the_member;
     }
 };