constcst.cpp

Think in C++ 第二版源码

//: C24:Constcst.cpp
// From Thinking in C++, 2nd Edition
// Available at http://www.BruceEckel.com
// (c) Bruce Eckel 1999
// Copyright notice in Copyright.txt
// Const casts

int main() {
  const int i = 0;
  int* j = (int*)&i; // Deprecated form
  j  = const_cast<int*>(&i); // Preferred
  // Can't do simultaneous additional casting:
//! long* l = const_cast<long*>(&i); // Error
  volatile int k = 0;
  int* u = const_cast<int*>(&k);
}

class X {
  int i;
// mutable int i; // A better approach
public:
  void f() const {
    // Casting away const-ness:
    (const_cast<X*>(this))->i = 1;
  }
}; ///:~