autocc.cpp

Thinking in C++ ２.０书籍源码光盘

//: C11:Autocc.cpp
// From Thinking in C++, 2nd Edition
// Available at http://www.BruceEckel.com
// (c) Bruce Eckel 1999
// Copyright notice in Copyright.txt
// Automatic copy-constructor
#include <iostream>
#include <cstring>
using namespace std;

class WithCC { // With copy-constructor
public:
  // Explicit default constructor required:
  WithCC() {}
  WithCC(const WithCC&) {
    cout << "WithCC(WithCC&)" << endl;
  }
};

class WoCC { // Without copy-constructor
  static const int bsz = 30;
  char buf[bsz];
public:
  WoCC(const char* msg = 0) {
    memset(buf, 0, bsz);
    if(msg) strncpy(buf, msg, bsz);
  }
  void print(const char* msg = 0) const {
    if(msg) cout << msg << ": ";
    cout << buf << endl;
  }
};

class Composite {
  WithCC withcc; // Embedded objects
  WoCC wocc;
public:
  Composite() : wocc("Composite()") {}
  void print(const char* msg = 0) {
    wocc.print(msg);
  }
};

int main() {
  Composite c;
  c.print("contents of c");
  cout << "calling Composite copy-constructor"
       << endl;
  Composite c2 = c;  // Calls copy-constructor
  c2.print("contents of c2");
} ///:~