C1123: Cannot instantiate abstract class as argument type

[ERROR]

Description

An abstract class may not be used as argument type

Example

  class A{

  public:

    virtual void f(void) = 0; // pure virtual function

                              // ==> A is an abstract class

};

  void main(void){

    void fct(A);

Tips

Use a pointer/reference to the object:

  void main(void){

    void fct(A *);

Use a derived class from abstract class

  class B : public A{

  public:

    void f(void){}

};

  void main(void){

    void fct(B);