#include <iostream>

 #include <functional>

 using namespace std;

 void main()

 {

     //&调用外部

     //function<void(void)> fun = [&]()->void {cout << "hello" << endl; fun(); };

     function<void(int)> fun = [&](int i)

     {

         if (i == )

         {

             return ;

         }

         else

         {

             cout << i << endl;

             fun(i-);

         }

     };

     fun();

     system("pause");

 }