message: Add cpp20::ref_view
diff: @@ -135,6 +135,13 @@ namespace ranges
  /// \ingroup group-views
  RANGES_INLINE_VARIABLE(view<ref_fn>, ref)
  }
  +
  + namespace cpp20
  + {
  + CPP_template(typename Rng)(
  + requires std::is_object<Rng>::value)
  + using ref_view = ranges::ref_view<Rng>;
  + }
  }
  RANGES_RE_ENABLE_WARNINGS
  