Example of using override and final in C++

override_final.cpp

#include <iostream>

// Virtual method declarations

struct A
{
    virtual void Foo() const;
};

struct B : public A
{
    void Foo() const override;
};

struct C : public B
{
    void Foo() const final;
};

// Virtual method definitions

void A::Foo() const
{ std::cout << "A:foo()\n"; }

void B::Foo() const
{ std::cout << "B::foo()\n"; }

void C::Foo() const
{ std::cout << "C::foo()\n"; }

int main()
{
    C c;
    A *a = &c;
    a->Foo();

    return 0;
}