C + + Learning record: operator = reload

"Effective C + +" is indeed a book of God, the sense of reading can be described in a hearty, it seems that a lot of small details previously did not care to become enlightened, in clause 10, Scott recommends that we overload the operator ' = ' When we return a *this reference.
Assignment, we can often write chained forms:
　　

int x,y,z;x = y = z = 10;

The assignment uses the right binding law, so the above chain assignment is parsed as:

x = (y = (z = 10));

First, 15 is assigned to Z, and then Z is updated to assign the value to x after the y,y update;
So in order to implement "chained assignment", the assignment operator must return a reference to the left argument of the operator.

class A{public:...    A& operator=(A& rhs)    {        ...        return *this;    }...};

C + + Learning record: operator = reload