MSVC error C4172 when overloading post-increment operator

Question

I'm using Visual Studio 2015 Update 3 and encountered the following warning while writing a simple class which basically is just a wrapper around an int.

The example below is not the actual class but a shorter example resulting in the same warning :

class Foo {

public:

    Foo() : x(23) {}
    Foo(int xx) : x(xx) {}
    Foo(const Foo& other) : x(other.x) {}

    Foo& operator++(int junk) {
        Foo copy(*this);
        this->x += 5;
        return copy;
    }
    int x;
};

In line 12 (return copy) I get the following warning:

warning C4172: returning address of local variable or temporary: copy

I'm confused because I think I'm not really returning an address or temporary because I thought the copy constructor of Foo would take care of such situations.

I would be really happy if someone could tell me what I'm missing here.

Also I found implementations of post increment operators just like this one in other stackoverflow articles as well (e.g. C++: overloading ++ for both pre and post increment

Thank you all in advance.

Change `Foo& operator++(int junk) {` to `Foo operator++(int junk) {` — drescherjm, Feb 09 '17 at 18:08
As you can see in *linked by you* post you need to return `Foo` (by copy) instead of `Foo&` (by reference). — Yuriy Ivaskevych, Feb 09 '17 at 18:09
***Also I found implementations of post increment operators just like this one in other stackoverflow articles as well*** You did not follow the implementation in the linked question however. — drescherjm, Feb 09 '17 at 18:09
Yes, you're right. I did not see this little detail. Thank you to all three of you. — Rafael Pasquay, Feb 09 '17 at 18:20

MSVC error C4172 when overloading post-increment operator

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