recycle4.cpp

Think in C++ 第二版源码

//: C25:Recycle4.cpp
// From Thinking in C++, 2nd Edition
// Available at http://www.BruceEckel.com
// (c) Bruce Eckel 1999
// Copyright notice in Copyright.txt
//{L} TrashPrototypeInit
//{L} fillBin Trash TrashStatics
// Adding TrashBins and TrashSorters
#include "Trash.h"
#include "Aluminum.h"
#include "Paper.h"
#include "Glass.h"
#include "Cardboard.h"
#include "fillBin.h"
#include "sumValue.h"
#include "../purge.h"
#include <fstream>
#include <vector>
using namespace std;
ofstream out("Recycle4.out");

class TBin : public vector<Trash*> {
public:
  virtual bool grab(Trash*) = 0;
};

template<class TrashType>
class TrashBin : public TBin {
public:
  bool grab(Trash* t) {
    TrashType* tp = dynamic_cast<TrashType*>(t);
    if(!tp) return false; // Not grabbed
    push_back(tp);
    return true; // Object grabbed
  }
};

class TrashSorter : public vector<TBin*> {
public:
  bool sort(Trash* t) {
    for(iterator it = begin(); it != end(); it++)
      if((*it)->grab(t))
        return true;
    return false;
  }
  void sortBin(vector<Trash*>& bin) {
    vector<Trash*>::iterator it;
    for(it = bin.begin(); it != bin.end(); it++)
      if(!sort(*it))
        cerr << "bin not found" << endl;
  }
  ~TrashSorter() { purge(*this); }
};

int main() {
  vector<Trash*> bin;
  // Fill up the Trash bin:
  fillBin("Trash.dat", bin);
  TrashSorter tbins;
  tbins.push_back(new TrashBin<Aluminum>());
  tbins.push_back(new TrashBin<Paper>());
  tbins.push_back(new TrashBin<Glass>());
  tbins.push_back(new TrashBin<Cardboard>());
  tbins.sortBin(bin);
  for(TrashSorter::iterator it = tbins.begin(); 
    it != tbins.end(); it++)
    sumValue(**it);
  sumValue(bin);
  purge(bin);
} ///:~