The current synopsis of std::generator is:

namespace std {
  template<class Ref, class V = void, class Allocator = void>
  class generator : public ranges::view_interface<generator<Ref, V, Allocator>> {
  // ...

When I first saw the naming of the second template parameter, I didn't quite understand what the V here was referring to and it seemed to be just an abbreviation for void. After I looked at it a few more times, I finally realized that it is actually the corresponding value type relative to the first template parameter Ref.

The class V = void here seems to be so simplified that it even made me misunderstand that it is just a common template name like U and has no meaning. It may be more friendly to change it to class Val = void.

Comments are welcome.