CppUG_final.h

struct base {
  virtual std::string name() { return "default"; }
  virtual void foo() final { }
};
 
struct derived final: public base {
   std::string name() override { return "derived!" }
   // compile error: overriding final function 'virtual void base::foo()'
   void foo() override { }
};
 
// compile error: cannot derive from 'final' base 'derived'
struct further_derived : public derived {
   std::string name() override { return "further derived!" }
};