Proposed resolution:

This wording is relative to n4917.

1. Modify [ranges.syn] as indicated:

   #include <compare>              // see [compare.syn]
   #include <initializer_list>     // see [initializer.list.syn]
   #include <iterator>             // see [iterator.synopsis]
   
   namespace std::ranges {
     […]
   
     // [range.as.const], as const view
     template<input_range R>
       constexpr auto& possibly-const-range(R& r) {          // exposition only
         if constexpr (constant_range<const R> && !constant_range<R>) {
           return const_cast<const R&>(r);
         } else {
           return r;
         }
       } 
     
     […]
   }
   

[ 2022-11-30 LWG telecon. Status changed: Tentatively NAD → NAD. ]

[ 2022-09-23; Reflector poll ]

Tentatively NAD. "const output ranges don’t seem to be useful."

Due to the possibly-const-range constraint that the template parameter R must model input_range, this makes the ranges::cend that tries using it for meaningful const casting never be applied to an output_range, even though const_sentinel does not require the template parameter S to model input_iterator.

This is unnecessary, we should relax its constraint.