求教复制构造函数的问题

#include<iostream.h>

class human
{
public:
    static int human_num;
    human()
      {
        human_num++;
      }
    ~human()
      {
        human_num--;
        print();
      }
    human(human &h)
    {
        human_num++;
        cout<<"copy construction"<<endl;
    }

    void print()
    {
        cout<<"human_num is:"<<human_num<<endl;
    }
};

int human::human_num=0;

human f1(human x)
{
    cout<<"what"<<endl;
    x.print();
    return x;
}

int main()
{
    human h1;
    h1.print();
    human h2=f1(h1);
   
    return 0;
}
输出结果为：
human_num is:1
copy construction//f1()函数形参传递时调用的复制构造参数
what
human_num is:2
copy construction//return 时调用的复制构造参数
human_num is:2//f1（）子函数临时变量的析构
human_num is:1//h2的析构
human_num is:0//h1的析构
但是如果把主函数修改为：
int main()
{
    human h1;
    h1.print();
    f1(h1);
   
    return 0;
}
结果还是上面的结果：这点我不明白
human_num is:1
copy construction
what
human_num is:2
copy construction
human_num is:2
human_num is:1
human_num is:0

求大侠指导,...