Initializing private static members

class foo
{
    private:
        static int i;
};

int foo::i = 0;

class foo
{
    private:
        static int i;
};

int foo::i = 0;

class foo
{
    private:
        static int const i = 42;
};

class foo
{
private:
    static int i;
};

int foo::i = 0;

class foo
{
private:
    static int i;
    const static int a = 42;
};

int foo::i = 0;

class A
{
    static B b;
}

__declspec(selectany) A::b;