by reference,by value的问题，请教！

代码如下：

#include <iostream>

#include <iterator>

#include <vector>

#include <algorithm>

#include <functional>

using namespace std;

class IntSequence

{

private:

	int value;

public:

	IntSequence( int init):value(init){}

	int operator()()

	{

		return value++;

	}

	void getvalue()

	{

		cout<<value<<endl;

	}

};

int main()

{

	vector<int> coll;

	IntSequence seq(13);

	generate_n<back_insert_iterator<vector<int> >,int,IntSequence&>(back_inserter(coll),9,seq);

        //by reference方式，对象seq的成员变量value应该会随之变化

	seq.getvalue();

        //然而，输出value仍然为13，不解,由此对vs2005产生了疑问？

	generate_n(back_inserter(coll),9,seq);

	copy(coll.begin(),coll.end(),ostream_iterator<int>(cout," "));

 	return 0;

}