libstdc++: Tweak common_iterator::operator-> return type [PR104443]

This adjusts the return type to match the resolution of LWG 3672. There
is no functional difference, because decltype(auto) always deduced a
value anyway, but this makes it simpler and consistent with the working
draft.

libstdc++-v3/ChangeLog:

	PR libstdc++/104443
	* include/bits/stl_iterator.h (common_iterator::operator->):
	Change return type to just auto.

(cherry picked from commit b5f5d1b36edbcd7d923f2e2653e54e52637c715b)

diff --git a/libstdc++-v3/include/bits/stl_iterator.h b/libstdc++-v3/include/bits/stl_iterator.h
index f2b315f30e464d112613287ffff01c7516db5718..15b9affc4b9004901f4fef4547451391f7fd277e 100644 (file)
--- a/libstdc++-v3/include/bits/stl_iterator.h
+++ b/libstdc++-v3/include/bits/stl_iterator.h
@@ -2043,7 +2043,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     }
 
     [[nodiscard]]
-    constexpr decltype(auto)
+    constexpr auto
     operator->() const requires __detail::__common_iter_has_arrow<_It>
     {
       __glibcxx_assert(_M_index == 0);