错误：非法将此类型用作表达式。 C ++

Question

I have created a static member function within the class Node, and want to invoke that function with some argument. How do I invoke that function in my main function?

class Node;
typedef shared_ptr<Node> SharedNode;

class Node {
    Node* parent;
    vector< SharedNode > children;
    int value;

    //limiting construction
    Node(int a_value):value(a_value),parent(0){}
    Node(const Node &copy); //non-construction-copyable
    Node& operator=(const Node& copy); //non-copyable
public:
    static SharedNode create(int a_value){
        return SharedNode(new Node(a_value));
    }
    SharedNode addChild(SharedNode child){
        child->parent = this;
        children.push_back(child);    // First there is a typo here. (nodes.push_back     is incorrent)
        return child;
    }


int main(){

    SharedNode a1 = Node.create(1);
    SharedNode b1 = Node.create(11);
    SharedNode b2 = Node.create(12);
    SharedNode b3 = Node.create(13);
    SharedNode b21 = Node.create(221);
    a1.get()->addChild(b1);
    a1.get()->addChild(b2);
    a1.get()->addChild(b3);
    b2.get()->addChild(b21);
    b2.get()->getNode(221);


    int hold;
    cin>>hold;
}

It gives me a Error: illegal use of this type as an expression. Thank you guys!

Answer 1

Statics are accessed using the :: operator not . so it should be Node::Create

Answer 2

Use:

Node::create(1)

to call the function

Answer 3

Static member functions or Static Data members are just one copy for the whole class and no separate copies for each instances.

So static members can be accessed only with class name and :: operator.

. Operator is used with only non static members or instance members.