Comment by TheAdamist

The new c++ alt function syntax talked about here: https://blog.petrzemek.net/2017/01/17/pros-and-cons-of-alter...

mentions replacing function declarations for

  void (*get_func_on(int i))(int); 

with

  auto get_func_on(int i) -> void (*)(int);

which looks a lot more readable to me.