Proposed resolution:

This wording is relative to n4917.

1. Modify [range.utility.conv.to] as indicated:

   template<class C, input_range R, class... Args> requires (!view<C>)
     constexpr C to(R&& r, Args&&... args);
   

   -1- Returns: An object of type C constructed from the elements of r in the following manner:

   1. (1.1) — If convertible_to<range_reference_t<R>, range_value_t<C>> is true:

      1. (1.1.1) — If constructible_from<C, R, Args...> is true:

         C(std::forward<R>(r), std::forward<Args>(args)...)

      2. (1.1.2) — Otherwise, if constructible_from<C, from_range_t, R, Args...> is true:

         C(from_range, std::forward<R>(r), std::forward<Args>(args)...)

      3. (1.1.3) — Otherwise, if

         1. (1.1.3.1) — common_range<R> is true,

         2. (1.1.3.2) — cpp17-input-iteratorif the qualified-id iterator_traits<iterator_t<R>>::iterator_category is true valid and denotes a type that models derived_from<input_iterator_tag>, and

         3. (1.1.3.3) — constructible_from<C, iterator_t<R>, sentinel_t<R>, Args...>:

            C(ranges::begin(r), ranges::end(r), std::forward<Args>(args)...)

      4. (1.1.4) — Otherwise, if

         1. (1.1.4.1) — constructible_from<C, Args...> is true, and

         2. (1.1.4.2) — container-insertable<C, range_reference_t<R>> is true:

            […]
            

   2. (1.2) — Otherwise, if input_range<range_reference_t<R>> is true:

      to<C>(r | views::transform([](auto&& elem) {
        return to<range_value_t<C>>(std::forward<decltype(elem)>(elem));
      }), std::forward<Args>(args)...);
      

   3. (1.3) — Otherwise, the program is ill-formed.