Java版本和C++版本简单Stack程序

现在对C++学习了一段时间，把C++的特性和Java做比较有很强烈的快感:P

自己写了两个版本的Stack:

Java版本:

源代码Stack.java
package org;
public class Stack ...{
public static class Link ...{

protected Object data;

protected Link next;

public Link(Object data, Link next) ...{
this.data = data;
this.next = next;
}
}

private Link head = null;

public void push(Object data) ...{
head = new Link(data, head);
}

public Object peek() ...{
return head.data;
}

public Object pop() ...{
if (head == null)
return null;
Object o = head.data;
head = head.next;
return o;
}

} 测试代码StackTest.java
package org;
import junit.framework.TestCase;

public class StackTest extends TestCase ...{

public void test1() ...{
Stack s = new Stack();

assertEquals(null, s.pop());

s.push("a");
s.push("b");

assertEquals("b", s.peek());
assertEquals("b", s.pop());
assertEquals("a", s.pop());

assertEquals(null, s.pop());
}

public void test2() ...{
Stack s = new Stack();

assertEquals(null, s.pop());

s.push(new Integer(1));
s.push(new Integer(2));

assertEquals(2, ((Integer)s.peek()).intValue());
assertEquals(2, ((Integer)s.pop()).intValue());
assertEquals(1, ((Integer)s.pop()).intValue());

assertEquals(null, s.pop());
}

}

C++版本:
源代码:
Stack.cpp
#include ＜fstream＞
#include ＜iostream＞
#include ＜string＞
using namespace std;

class Stack ...{
struct Link ...{
Link* next;
void* data;
Link(void* dat, Link* nxt) : data(dat) ,next(nxt) ...{}
}*head;

public :
Stack() : head(0) ...{}

void push(void* data) ...{
head = new Link(data, head);
}

void* pop() ...{
if (head == 0)
return 0;
void* object = head->data;
Link* oldHead = head;
head = oldHead->next;
delete oldHead;
return object;
}

void* peek() ...{
return head ? head->data : 0;
}
};

int main() ...{
ifstream in("Stack.cpp");
Stack text;
string line;
while(getline(in, line))
text.push(new string(line));
string* s;
while((s = (string*)text.pop()) != 0) ...{
cout << *s << endl;
delete s;
}
}