To overcome the ambiguity occurring due to multipath inheritance, the C++ provides the key-
word virtual. The keyword virtual declares the specified classes virtual. The example
given below illustrates the virtual classes:
class A1
{
protected:
int a1;
};
class A2 : virtual public A1 //
virtual class declaration
{
protected:
int a2;
};
class A3: virtual public A1 //
virtual class declaration
{
protected:
int a3;
};
class A4: public A2,A3
{
int a4;
};
When classes are declared as virtual, the compiler takes essential caution to avoid the duplication
of member variables. Thus, we make a class virtual if it is a base class ...
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