Proposed resolution:

This wording is relative to N4830.

1. Modify [range.split.outer.value], class split_view::outer_iterator::value_type synopsis, as indicated:

   namespace std::ranges {
     template<class V, class Pattern>
     template<bool Const>
     struct split_view<V, Pattern>::outer_iterator<Const>::value_type 
       : view_interface<value_type> {
     private:
       outer_iterator i_ = outer_iterator(); // exposition only
     public:
       value_type() = default;
       constexpr explicit value_type(outer_iterator i);
   
       constexpr inner_iterator<Const> begin() const;
       constexpr default_sentinel_t end() const;
     };
   }
   

[ 2019-09-24 Issue Prioritization ]

Status to Tentatively Ready and priority to 0 after six positive votes on the reflector.

It is a view. It should have all the view goodies. Suggested priority P1 because it affects ABI.

The proposed change has been implemented and tested in range-v3.