C++ operator oveload

Question

I have the following class declaration:

Class A { A &operator =(const ACHAR *s); // (1) A &operator =(A &a); // (2) A operator +(const ACHAR *s); // (3) operator ACHAR*(); // (4) };

Now, when I run this code:

A x,y; ACHAR *p; x=y; // (2) x=y+p; (3)(4)(1)

The first assignment x=y invoke the (2) operator=, as expected.

But the second assignment provoke the cast operator, and the (1) operator=.

Now, since the (3) operator+ returns class A, I would expect (2) operator= to be called.

Why is this happen, and how to resolve *this?

Thanks in advance!

Edgar Rokjān · Accepted Answer · 2018-01-28 11:03:02Z

A& operator=(A& a);

it should be:

A& operator=(const A &a); ^^^^^

In your case y + p produces an rvalue of type A which cannot be captured by non-const reference A&, so 4 and 1 are called instead of 2.

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