Thread of a member function

Mainly for test purposes,

I want to run a member function on a thread.

Endless tries - and still, only error messages,

Please - can anyone explain the cause of the error and some best practices of doing so? Thanks

#include <thread>
#include <iostream>

using namespace std;

class Test {
public:
    int x = 1;
    int y = 7;
    int a() {
        for (int i = 1; i < 1000; i++) {
            x += y;
           cout << "x:" << x << endl;
        }
        return x;
    }
    int b() {
        for (int i = 1; i < 1000; i++) {
            y -= 0.5 * x;
            cout << "y:" << y << endl;
        }
        return y;
    }
    Test() {

    }
    Test* run() {
        thread(&Test::a, this);
        //thread(&Test::b, this);
        return this;
    }
};

int main()
{
    Test* obj = new Test();
    obj->run();
    return 0;
}