simple C++ basic factory pattern failing

I am new to c++ and am trying a basic factory pattern in C++11 but is failing with error: 'X' does not refer to a value. Any suggestions?

Test Code: X instance = X.createNewInstance();

Original Class

class X
{
public:

    static X createNewInstance() {
        return X();
    };


    void foo() ;

private:

    X(){};

};