LWG3953 iter_move for common_iterator and counted_iterator should return decltype(auto)

Author: burblebee

source/iterators.tex

@@ -5458,7 +5458,7 @@
     friend constexpr iter_difference_t<I2> operator-(
       const common_iterator& x, const common_iterator<I2, S2>& y);
 
-    friend constexpr iter_rvalue_reference_t<I> iter_move(const common_iterator& i)
+    friend constexpr decltype(auto) iter_move(const common_iterator& i)
       noexcept(noexcept(ranges::iter_move(declval<const I&>())))
         requires @\libconcept{input_iterator}@<I>;
     template<@\libconcept{indirectly_swappable}@<I> I2, class S2>
@@ -5800,7 +5800,7 @@
 
 \indexlibrarymember{iter_move}{common_iterator}%
 \begin{itemdecl}
-friend constexpr iter_rvalue_reference_t<I> iter_move(const common_iterator& i)
+friend constexpr decltype(auto) iter_move(const common_iterator& i)
   noexcept(noexcept(ranges::iter_move(declval<const I&>())))
     requires @\libconcept{input_iterator}@<I>;
 \end{itemdecl}
@@ -5959,7 +5959,7 @@
       friend constexpr strong_ordering operator<=>(
         const counted_iterator& x, const counted_iterator<I2>& y);
 
-    friend constexpr iter_rvalue_reference_t<I> iter_move(const counted_iterator& i)
+    friend constexpr decltype(auto) iter_move(const counted_iterator& i)
       noexcept(noexcept(ranges::iter_move(i.current)))
         requires @\libconcept{input_iterator}@<I>;
     template<@\libconcept{indirectly_swappable}@<I> I2>
@@ -6387,7 +6387,7 @@
 
 \indexlibrarymember{iter_move}{counted_iterator}%
 \begin{itemdecl}
-friend constexpr iter_rvalue_reference_t<I>
+friend constexpr decltype(auto)
   iter_move(const counted_iterator& i)
     noexcept(noexcept(ranges::iter_move(i.current)))
     requires @\libconcept{input_iterator}@<I>;