Thread: friendly assignment operator

I'm having difficulty writing a friend operator, checkout the code below. The first operator compiles fine, but the second (the “=” operator) gives me a bunch of errors (first of which says “error C2801: 'operator =' must be a non-static member” in VC++ 2003). Is it illegal to define a friend operator for assignment? Thanks.

Code:

class A {
public:

	int x;
};

class B {
public:

	friend A& operator += (A &a, const B &b) {
		a.x = 1;
		return a;
	}

	friend A& operator = (A &a, const B &b) { // is this legal?
		a.x = 2;
		return a;
	}
};