using2.hpp

The following code example is taken from the book
C++17 - The Complete Guide by Nicolai M. Josuttis, Leanpub, 2017
The code is licensed under a Creative Commons Attribution 4.0 International License.

---

template<typename T>
class Base {
    T value{};
  public:
    Base() {
      //...
    }
    Base(T v) : value{v} {
      //...
    }
    //...
};

template<typename... Types>
class Multi : private Base<Types>...
{
  public:
    // derive all constructors:
    using Base<Types>::Base...;
    //...
};