constf.cpp

Thinking in C++ 2nd edition source code which are all the cores of the book Thinking in C++ second e

//: C03:Constf.cpp
// From Thinking in C++, 2nd Edition
// at http://www.BruceEckel.com
// (c) Bruce Eckel 1999
// Copyright notice in Copyright.txt
// const member functions
// Compiler checks for proper use of const
class CMembers {
  int x;
public:
  CMembers(int X) { x = X; }
  int X() const { return x; }
  int XX() { return x; }  // Non-const, doesn't modify
//!  int incr() const { return ++x; } // Error
  void g() const; // Non-inline
};
void CMembers::g() const {
//!  x++;  // Error
}
int main() {
  CMembers A(1);
  const CMembers B(2);
  A.X();  // Can call any member function for non-const objects
  A.XX();
//!  A.incr();
  A.g();
  B.X(); // Can only call const members for const objects
//!  B.incr();
  B.g();
//!  B.XX();   // Error
} ///:~