Calling a virtual function on a reference

Question

In the following code, why does the last call of eat() on the reference c return \"An animal b is eating.\" ? From my

Answer 1

Because you can't rebind references. Once you initialized them, their name always refers to the object you have initialized them with.

An object can have a name, e.g. Animal a("A"); creates an object of type Animal and introduces a name a which refers to this object.

References on the other hand introduce names without introducing objects (let's not consider temporaries):

Animal& c = a; // a new name `c` which refers to the same object as `a`

// another (evil) example:
Animal& c = *(new Animal("C")); // `new` introduces an object without name
                                // `c` now refers to this object

Concerning the assignment:

Animal & c = a;
// the name `c` is now equivalent to the name `a`

c = b; // equivalent to `a = b;`

This last assignment takes the object referred to by b, and copies its sub-object of type Animal to the object which c refers to. As a and c are equivalent, that's the same object a refers to. Therefore, a.name is set to "B".

The virtual function call c.eat() of course operates on an id-expression (c) whose dynamic type is Animal - the same type as a - therefore, Animal::eat is called instead of Dog::eat.