#include <iostream>

 bool allVar(){
   return true;
 }

 template<typename T, typename ...Ts>
 bool allVar(T t, Ts ... ts){
   return t && allVar(ts...);
 }

 template<typename... Args>
 bool all(Args... args) { return (... && args); }

 int main(){

   std::cout << std::boolalpha;

   std::cout << "allVar(): " << allVar() << std::endl;
   std::cout << "all(): " << all() << std::endl;

   std::cout << "allVar(true): " << allVar(true) << std::endl;
   std::cout << "all(true): " << all(true) << std::endl;

   std::cout << "allVar(true, true, true, false): " << allVar(true, true, true, false) << std::endl;
   std::cout << "all(true, true, true, false): " << all(true, true, true, false) << std::endl;

 }