有关C++内部类的一段有趣代码

#include<stdio.h>
#include<time.h>
#include <list>
#include <stack>
#include <iostream>
#include <vector>
#include <string>
#include <time.h>

using namespace std;

class OuterClass
{

private:
int  m_outVar;

public:
OuterClass ( int n )
{
m_outVar = n;
}

class Nest
{

public:
Nest ( OuterClass& b )
{
cout << b.m_outVar << endl;
}
};

void ff()
{

class DDD
{

public:
DDD()
{
cout << "DDD::DDD" << endl;
}

public :
int m_dddVar;
};

static DDD d;
}
};

int main ( void )
{

class DD: public OuterClass
{

public:
DD() : OuterClass ( 5 )
{
cout << "DD::DD" << endl;
}

public :
int m_dddVar;
};

static DD d;

OuterClass b ( 9 );

OuterClass::Nest n ( b );

b.ff(); //注释掉，看看结果

return 0;
}