nested.cpp

来自「Thinking in C++ 2nd edition source code 」· C++ 代码 · 共 47 行

//: C04:Nested.cpp {O}
// From Thinking in C++, 2nd Edition
// at http://www.BruceEckel.com
// (c) Bruce Eckel 1999
// Copyright notice in Copyright.txt
// Linked list with nesting
#include <cstdlib>
#include "../require.h"
#include "Nested.h"
using namespace std;

void Stack::link::initialize(
    void* Data, link* Next) {
  data = Data;
  next = Next;
}

void Stack::initialize() { head = 0; }

void Stack::push(void* Data) {
  link* newlink = (link*)malloc(sizeof(link));
  require(newlink != 0);
  newlink->initialize(Data, head);
  head = newlink;
}

void* Stack::peek() { return head->data; }

void* Stack::pop() {
  if(head == 0) return 0;
  void* result = head->data;
  link* oldHead = head;
  head = head->next;
  free(oldHead);
  return result;
}

void Stack::cleanup() {
  link* cursor = head;
  while(head) {
    cursor = cursor->next;
    free(head->data); // Assumes a malloc!
    free(head);
    head = cursor;
  }
} ///:~