From: Jonathan Wakely <jwakely@redhat.com>
Date: Thu, 11 Sep 2025 16:39:43 +0000 (+0100)
Subject: libstdc++: ranges::rotate should not use 'auto' with ranges::iter_move [PR121913]
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=412a1f78b53709ee60d7b17393cc3a9c9e0b973c;p=thirdparty%2Fgcc.git

libstdc++: ranges::rotate should not use 'auto' with ranges::iter_move [PR121913]

The r16-3835-g7801236069a95c change to use ranges::iter_move should also
have used iter_value_t<_Iter> to ensure we get an object of the value
type, not a proxy reference.

libstdc++-v3/ChangeLog:

	PR libstdc++/121913
	* include/bits/ranges_algo.h (__rotate_fn::operator()): Use
	auto_value_t<_Iter> instead of deduced type.

Reviewed-by: Patrick Palka <ppalka@redhat.com>
---

diff --git a/libstdc++-v3/include/bits/ranges_algo.h b/libstdc++-v3/include/bits/ranges_algo.h
index ea933be2f60..4025bba9f20 100644
--- a/libstdc++-v3/include/bits/ranges_algo.h
+++ b/libstdc++-v3/include/bits/ranges_algo.h
@@ -1685,7 +1685,7 @@ namespace ranges
 			{
 			  auto __mid = ranges::next(__p, __n - 1);
 			  auto __end = ranges::next(__mid);
-			  auto __t = ranges::iter_move(__p);
+			  iter_value_t<_Iter> __t(ranges::iter_move(__p));
 			  ranges::move(ranges::next(__p), __end, __p);
 			  *__mid = std::move(__t);
 			  return {std::move(__ret), std::move(__lasti)};
@@ -1713,7 +1713,7 @@ namespace ranges
 			{
 			  auto __mid = ranges::next(__p, __n - 1);
 			  auto __end = ranges::next(__mid);
-			  auto __t = ranges::iter_move(__mid);
+			  iter_value_t<_Iter> __t(ranges::iter_move(__mid));
 			  ranges::move_backward(__p, __mid, __end);
 			  *__p = std::move(__t);
 			  return {std::move(__ret), std::move(__lasti)};