Inheritance case study #2: Implementing interface inside a base class

class D1 {

public:

virtual void Test(int a) = 0;

};

class D4 {

public:

void Test(int d){

}

};

class D5 : public D1, public D4 {

public:

};

Inheritance case study #1: Inheriting an identical interface from two different classes

class D1 {

public:

virtual void Test(int a) = 0;

};

class D2 {

public:

virtual void Test(int b) = 0;

};

class D3 : public D1, public D2 {

public:

void Test(int c){

}

};