c++ unique_ptr argument passing

Suppose I have the following code:

class B { /* */ };

class A {
    vector<B*> vb;
public:
    void add(B* b) { vb.push_back(b); }
};


int main() {

    A a;
    B* b(new B());
    a.add(b);
}

Suppose that in this case, all raw pointers B* can be handled through unique_ptr<B>.

Surprisingly, I wasn't able to find how to convert this code using unique_ptr. After a few tries, I came up with the following code, which compiles:

class A {
    vector<unique_ptr<B>> vb;
public:
    void add(unique_ptr<B> b) { vb.push_back(move(b)); }
};


int main() {

    A a;
    unique_ptr<B> b(new B());
    a.add(move(b));
}

So my simple question: is this the way to do it and in particular, is move(b) the only way to do it? (I was thinking of rvalue references but I don't fully understand them.)

And if you have a link with complete explanations of move semantics, unique_ptr, etc. that I was not able to find, don't hesitate to share it.

EDIT According to http://thbecker.net/articles/rvalue_references/section_01.html, my code seems to be OK.

Actually, std::move is just syntactic sugar. With object x of class X, move(x) is just the same as:

static_cast <X&&>(x)

These 2 move functions are needed because casting to a rvalue reference:

1. prevents function "add" from passing by value
2. makes push_back use the default move constructor of B

Apparently, I do not need the second std::move in my main() if I change my "add" function to pass by reference (ordinary lvalue ref).

I would like some confirmation of all this, though...