staticmemberfunctions.cpp

ThinkingC++中文版

//: C10:StaticMemberFunctions.cpp
// From Thinking in C++, 2nd Edition
// Available at http://www.BruceEckel.com
// (c) Bruce Eckel 2000
// Copyright notice in Copyright.txt
class X {
  int i;
  static int j;
public:
  X(int ii = 0) : i(ii) {
     // Non-static member function can access
     // static member function or data:
    j = i;
  }
  int val() const { return i; }
  static int incr() {
    //! i++; // Error: static member function
    // cannot access non-static member data
    return ++j;
  }
  static int f()
  {
    //! val(); // Error: static member function
    // cannot access non-static member function
    return incr(); // OK -- calls static
  }	
};

int X::j = 0;



void main() {
  X x;
  X* xp = &x;
  x.f();
  xp->f();
  X::f(); // Only works with static members
} ///:~