overloadingoperatorcomma.cpp

Thinking in c++ 2nd edition,c++编程思想（第2版）

//: C12:OverloadingOperatorComma.cpp
// From Thinking in C++, 2nd Edition
// Available at http://www.BruceEckel.com
// (c) Bruce Eckel 2000
// Copyright notice in Copyright.txt
#include <iostream>
using namespace std;

class After {
public:
  const After& operator,(const After&) const {
    cout << "After::operator,()" << endl;
    return *this;
  }
};

class Before {};

Before& operator,(int, Before& b) {
  cout << "Before::operator,()" << endl;
  return b;
}

int main() {
  After a, b;
  a, b;  // Operator comma called

  Before c;
  1, c;  // Operator comma called
} ///:~