inheritstack.cpp

来自「thingking in c++（C++编程思想） 各章节课后练习的答案」· C++ 代码 · 共 47 行

//: C14:InheritStack.cpp
// From Thinking in C++, 2nd Edition
// Available at http://www.BruceEckel.com
// (c) Bruce Eckel 2000
// Copyright notice in Copyright.txt
// Specializing the Stack class
#include "../C09/Stack4.h"
#include "../require.h"
#include <iostream>
#include <fstream>
#include <string>
using namespace std;

class StringStack : public Stack {
public:
  void push(string* str) {
    Stack::push(str);
  }
  string* peek() const {
    return (string*)Stack::peek();
  }
  string* pop() {
    return (string*)Stack::pop();
  }
  ~StringStack() {
    string* top = pop();
    while(top) {
      delete top;
      top = pop();
    }
  }
};

int main() {
  ifstream in("InheritStack.cpp");
  assure(in, "InheritStack.cpp");
  string line;
  StringStack textlines;
  while(getline(in, line))
    textlines.push(new string(line));
  string* s;
  while((s = textlines.pop()) != 0) { // No cast!
    cout << *s << endl;
    delete s;
  }
} ///:~