// From: http://en.cppreference.com/w/cpp/language/const_cast

#include <iostream>
 
class MyType {
public:
  MyType() {i=3;}
  void m1(int v) const {
    // this->i = v;                 // compile error: this is a pointer to const
    const_cast<MyType*>(this)->i = v; // OK as long as the MyType object isn't const,
                                      // in which case what happens is undefined
  }
  int get() { return i; }
private:
  int i;
};
 
int main() {
  int i = 3;                    // i is not declared const
  const int& cref_i = i; 
  const_cast<int&>(cref_i) = 4; // OK: modifies i
  std::cout << "i = " << i << std::endl;
 
  MyType t; // note, if this is const MyType t;, then t.m1(4); is UB
  t.m1(5);
  std::cout << "MyType::i = " << t.get() << std::endl;
 
  const int j = 3; // j is declared const
  int* pj = const_cast<int*>(&j);
  *pj = 4;         // undefined behavior!
  
  void (MyType::*mfp)(int) const = &MyType::m1; // pointer to member function
//  const_cast<void(MyType::*)(int)>(mfp); // compiler error: const_cast does not
                                           // work on function pointers
}