typename...

https://msdn.microsoft.com/zh-cn/library/dn439779.aspx

#include <iostream>  
  
using namespace std;  
  
void print() {  
    cout << endl;  
}  
  
template <typename T> void print(const T& t) {  
    cout << t << endl;  
}  
  
template <typename First, typename... Rest> void print(const First& first, const Rest&... rest) {  
    cout << first << ", ";  
    print(rest...); // recursive call using pack expansion syntax  
}  
  
int main()  
{  
    print(); // calls first overload, outputting only a newline  
    print(1); // calls second overload  
  
    // these call the third overload, the variadic template,   
    // which uses recursion as needed.  
    print(10, 20);  
    print(100, 200, 300);  
    print("first", 2, "third", 3.14159);  
}