union.cpp

来自「Thinking_in_C___2.rar」· C++ 代码 · 共 26 行

//: C03:Union.cpp
// From Thinking in C++, 2nd Edition
// at http://www.BruceEckel.com
// (c) Bruce Eckel 1999
// Copyright notice in Copyright.txt
// The size and simple use of a union
#include <iostream>
using namespace std;

union packed { // Declaration similar to a class
  char i;
  short j;
  int k;
  long l;
  float f;
  double d;  // The union will be the size of a double,
             // since it's the largest element
};  // Semicolon ends a union, like a class

int main() {
  cout << "sizeof(packed) = " << sizeof(packed) << endl;
  packed X;
  X.i = 'c';
  X.d = 3.14159;
} ///:~