C++ identifier with special meaning: final (since C++11)

struct b0 final {};
struct d0 : b0 {}; // Error: cannot derive from final base
 
struct b1
{
    virtual void f0() final;
    virtual void f1();
};
 
struct d1 : b1 // OK
{
    void f0(); // Error: cannot override final function
    void f1(); // OK
};