C1124: Cannot instantiate abstract class as return type

[ERROR]

Description

An abstract class may not be used as a function return type.

Example

  class A{

  public:

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

                              //is an abstract class

};

  void main(void){

    A fct(void);

Tips

Use a pointer/reference to the object

  void main(void){

    A *fct(void);

Use a derived class from abstract class

  class B : public A{

  public:

    void f(void){}

};

  void main(void){

    B fct(void);