Why does overloaded assignment operator return reference to class?

Question

class item {
public:
    item& operator=(const item &rh) {
        ...
        ...
        return *this;
    }
};

Is the following signatur

Answer 1

It is not "wrong", but surprising. An assignment evaluates to the target object. That's what the builtin meaning is. If you define it different for your own class, people could become confused.

Example:

int c;
while((c = getchar()) != EOF) {
  // ...
}

The assignment to c returned c itself and compared it to EOF afterwards. Users would expect your item class to behave similar.