Why cannot a non-member function be used for overloading the assignment operator?

Question

The assignment operator can be overloaded using a member function but not a non-member friend function:

class Test
{
    int a;
public:
    Test         


        

Answer 1

operator= is a special member function that the compiler will provide if you don't declare it yourself. Because of this special status of operator= it makes sense ro require it to be a member function, so there is no possibility of there being both a compiler-generated member operator= and a user-declared friend operator= and no possibility of choosing between the two.