Passing static method as argument, no address-of operator required?

class ThreadWorker
{
public:
    ThreadWorker(void);
    virtual ~ThreadWorker(void);

    static void DoSomething();
};


int main()
{
    boost::thread thread1(ThreadWorker::DoSomething);
    boost::thread thread2(ThreadWorker::DoSomething);
    boost::thread thread3(&ThreadWorker::DoSomething);
}

I'm playing around with Boost.Thread and I notice it doesn't seem to matter whether I use the address of operator (&) or not when passing a static member function as an argument. Does it not matter? And if not, why? Is one way more correct than the other?

It effectively does not matter. Functions (free functions and static member functions, not non-static member functions) decay to function pointers. No way is more correct than the other, I happen to prefer the explicit one though.

C++11 Standard, 4.3/1:

An lvalue of function type T can be converted to a prvalue of type “pointer to T.” The result is a pointer to the function.

C++11 Standard, 5.2.2/1 - Function call:

There are two kinds of function call: ordinary function call and member function call. A static member function is an ordinary function.