mallocclass.cpp

ThinkingC++中文版

//: C13:MallocClass.cpp
// From Thinking in C++, 2nd Edition
// Available at http://www.BruceEckel.com
// (c) Bruce Eckel 2000
// Copyright notice in Copyright.txt
// Malloc with class objects
// What you'd have to do if not for "new"
#include "../require.h"
#include <cstdlib> // malloc() & free()
#include <cstring> // memset()
#include <iostream>
using namespace std;

class Obj {
  int i, j, k;
  enum { sz = 100 };
  char buf[sz];
public:
  void initialize() { // Can't use constructor
    cout << "initializing Obj" << endl;
    i = j = k = 0;
    memset(buf, 0, sz);
  }
  void destroy() const { // Can't use destructor
    cout << "destroying Obj" << endl;
  }
};

int main() {
  Obj* obj = (Obj*)malloc(sizeof(Obj));
  require(obj != 0);
  obj->initialize();
  // ... sometime later:
  obj->destroy();
  free(obj);
} ///:~