C++23 is going to bring us a few changes regarding move operations. It mostly means extended support in the standard library, but there is also one change directly in the language. Let’s start with that.

C++23 likes to move it!

by Sandor Dargo

From the article:

P2266R3 is a quite great proposal both in terms of its high-quality explanation and the amount of proposed changes in wording. I think if you’re interested in exploring a readable proposal, this might be the one.

Let me try to summarize it briefly.

Since the introduction of move semantics and rvalue references in C++11, we can return move-only types by value:

struct Widget {
    Widget(Widget&&);
};

Widget one(Widget w) {
    return w;
}

C++14 extended this support so that even converting constructors accepting an rvalue type can be called to invoke an implicit move.

struct RRefTaker {
    RRefTaker(Widget&&); // here is the converting constructor
};

RRefTaker two(Widget w) {
    return w;
}

As you can see, the two examples...