Method operator++

tests/ClassOperatorHandler2Test.cpp:24–31

    operator const int() const { return mX; }
    Foo operator++(int)
    {
        Foo old(*this);
        printf("  ======\n");
        ++mX;
        printf("  ++++++\n");
        return old;
    }
    Foo& operator++()
    {
        ++mX;