#include <iostream>
#include <vector>
#include <memory>

template <typename T, template <typename...> typename CONT>
class stack {
public:
  auto push(T t) -> void { stack_.push_back(t); }
  auto pop() -> void { stack_.pop_back(); }
  auto top() -> T& { return stack_.back(); }
  auto empty() const -> bool { return stack_.empty(); }
private:
  CONT<T> stack_;
};

#include <iostream>
#include <vector>

auto main(void) -> int {
  auto s1 = stack<int, std::vector>{};
  s1.push(1);
  s1.push(2);
}