double colon for instance variables in c++

Question

I have always been under the impression that <class>::<variable> is for accessing static members. However, I am surprised to find out that the following compiles just fine. (I would have used this-> as shown in the inline comment.)

Further investigation on Google/StackOverflow doesn't show anything pertinent to this behavior, I wonder if anyone could shed some light on this.

class Test {
    private:
        int x;
    public:
    void set_x(int x) {
        // this->x = x;
        Test::x = x;
    }
};

int main(int argc, char *argv[])
{
    return 0;
}

ENV: clang version 7.0.0- (trunk)

Answer 1

The :: is the scope-resolution operator and can be used to specify which of a number of symbols of the same name but different but visible scope the reference refers to.

Either scope-resolution or this-> may be used in this example, but scope-resolution itself has more general applicability within the language.