message: replace camp::integral_constant with camp::sink to avoid pack fold expression (c++17)
diff: @@ -250,10 +250,10 @@ return camp::integral_constant<size_t,
  std::get<N>(std::array<size_t,sizeof...(I)> { I... }) >();
  }
  //compile time loop over an integer sequence
  -//this allows for creating a loop over a compile time
  +//this allows for creating a loop over a compile time constant variable
  template <typename Func, typename T, T... ts>
  static void seq_for(camp::int_seq<T, ts...>, Func func) {
  - (static_cast<void>(f(camp::integral_constant<T, ts>{})), ...);
  + static_cast<void>(camp::sink((f(camp::integral_constant<T,ts>{}), 0)...));
  }
  template<size_t N, typename Func>
  static void seq_for(Func func) {
  