cleanup.cpp

来自「Think in C++文中代码实现」· C++ 代码 · 共 97 行

// File from page 697 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).
//////////////////////////////////////////////////

//: CLEANUP.CPP -- Exceptions clean up objects
#include <fstream.h>
#include <except.h>
#include <string.h>

ofstream out("cleanup.out");

class noisy {
  static int i;
  int objnum;
  enum { sz = 40 };
  char name[sz];
public:
  noisy(const char* nm="array elem") throw(int){
    objnum = i++;
    memset(name, 0, sz);
    strncpy(name, nm, sz - 1);
    out << "constructing noisy " << objnum
      << " name [" << name << "]" << endl;
    if(objnum == 5) throw int(5);
    // Not in exception specification:
    if(*nm == 'z') throw char('z');
  }
  ~noisy() {
    out << "destructing noisy " << objnum
      << " name [" << name << "]" << endl;
  }
  void* operator new[](size_t sz) {
    out << "noisy::new[]" << endl;
    return ::new char[sz];
  }
  void operator delete[](void* p) {
    out << "noisy::delete[]" << endl;
    ::delete []p;
  }
};

int noisy::i = 0;

void unexpected_rethrow() {
  out << "inside unexpected_rethrow()" << endl;
  throw; // Rethrow same exception
}

main() {
  set_unexpected(unexpected_rethrow);
  try {
    noisy n1("before array");
    // Throws exception:
    noisy* array = new noisy[7];
    noisy n2("after array");
  } catch(int i) {
    out << "caught " << i << endl;
  }
  out << "testing unexpected:" << endl;
  try {
    noisy n3("before unexpected");
    noisy n4("z");
    noisy n5("after unexpected");
  } catch(char c) {
    out << "caught " << c << endl;
  }
}