Difference between func() and (*this).func() in C++

There actually is a difference, but in a very non-trivial context. Consider this code:

void func ( )
{
    std::cout << "Free function" << std::endl;
}

template <typename Derived>
struct test : Derived
{
    void f ( )
    {
        func(); // 1
        this->func(); // 2
    }
};

struct derived
{
    void func ( )
    {
        std::cout << "Method" << std::endl;
    }
};

test<derived> t;

Now, if we call t.f(), the first line of test::f will invoke the free function func, while the second line will call derived::func.