copymem.cpp

来自「Think in C++文中代码实现」· C++ 代码 · 共 66 行

// File from page 434 in "Thinking in C++" by Bruce Eckel
//////////////////////////////////////////////////
// From the compressed package ECKELT02.ZIP 4/11/95
// (Original ECKELT01.ZIP dated 2/21/95)
// Copyright (c) Bruce Eckel, 1995 
// Source code file from the book "Thinking in C++", 
// Prentice Hall, 1995, ISBN: 0-13-917709-4
// All rights reserved EXCEPT as allowed by the following 
// statements: You may freely use this file for your own 
// work, including modifications and distribution in 
// executable form only. You may copy and distribute this 
// file, as long as it is only distributed in the complete 
// (compressed) package with the other files from this 
// book and you do not remove this copyright and notice. 
// You may not distribute modified versions of the source 
// code in this package. This package may be freely placed 
// on bulletin boards, internet nodes, shareware disks and 
// product vendor disks. You may not use this file in 
// printed media without the express permission of the 
// author. Bruce Eckel makes no 
// representation about the suitability of this software 
// for any purpose. It is provided "as is" without express 
// or implied warranty of any kind. The entire risk as to 
// the quality and performance of the software is with 
// you. Should the software prove defective, you assume 
// the cost of all necessary servicing, repair, or 
// correction. 
// If you think you've found an error, please 
// email all modified files with loudly commented changes 
// to: [e-mail] (please use the same 
// address for non-code errors found in the book).
//////////////////////////////////////////////////

//: COPYMEM.CPP -- Duplicate during assignment
#include <stdlib.h>
#include <string.h>
#include "..\allege.h"

class withPointer {
  char* p;
  enum { blocksz = 100 };
public:
  withPointer() {
    p = (char*)malloc(blocksz);
    allegemem(p);
    memset(p, 1, blocksz);
  }
  withPointer(const withPointer& wp) {
    p = (char*)malloc(blocksz);
    allegemem(p);
    memcpy(p, wp.p, blocksz);
  }
  withPointer&
  operator=(const withPointer& wp) {
    // Check for self-assignment:
    if(&wp != this)
      memcpy(p, wp.p, blocksz);
    return *this;
  }
  ~withPointer() {
    free(p);
  }
};

main() {}