virtual_call_by_value.cc

#include <iostream>

class Base {
 public:
  virtual int func() {
    return 0;
  }
};

class Derived1 : public Base {
 public:
  virtual int func() {
    return 1;
  }
};

int main() {
  Base b;
  Derived1 d1;
  std::cout << b.func() << std::endl;
  std::cout << d1.func() << std::endl;
  b = d1;
  std::cout << b.func() << std::endl;
  Base& b2 = d1;
  std::cout << b2.func() << std::endl;
  return 0;
}