迭代器模式

 1 #include <iostream>
 2 #include <string>
 3 using namespace std;
 4 
 5 class Iterator;
 6 
 7 class Aggregate
 8 {
 9 public:
10     virtual Iterator *createIterator() = 0;
11 };
12 
13 class Iterator
14 {
15 public:
16     virtual void first() = 0;
17     virtual void next() = 0;
18     virtual bool isDone() = 0;
19 };
20 
21 class ConcreteAggregate : public Iterator
22 {
23 public:
24     void first()
25     {}
26     void next()
27     {}
28     bool isDone()
29     {}
30 };
31 
32 int main()
33 {
34     return 0;
35 }