https://gcc.gnu.org/g:c29c3f713a9d166eb18c68645b9675d01421ccf6
commit r14-11625-gc29c3f713a9d166eb18c68645b9675d01421ccf6
Author: Jonathan Wakely <jwak...@redhat.com>
Date: Thu Feb 27 13:27:17 2025 +0000
libstdc++: Fix ranges::move and ranges::move_backward to use iter_move
[PR105609]
The ranges::move and ranges::move_backward algorithms are supposed to
use ranges::iter_move(iter) instead of std::move(*iter), which matters
for an iterator type with an iter_move overload findable by ADL.
Currently those algorithms use std::__assign_one which uses std::move,
so define a new ranges::__detail::__assign_one helper function that uses
ranges::iter_move.
libstdc++-v3/ChangeLog:
PR libstdc++/105609
* include/bits/ranges_algobase.h (__detail::__assign_one): New
helper function.
(__copy_or_move, __copy_or_move_backward): Use new function
instead of std::__assign_one.
* testsuite/25_algorithms/move/constrained.cc: Check that
ADL iter_move is used in preference to std::move.
* testsuite/25_algorithms/move_backward/constrained.cc:
Likewise.
(cherry picked from commit 3866ca796d5281d33f25b4165badacf8f198c6d1)
Diff:
---
libstdc++-v3/include/bits/ranges_algobase.h | 26 ++++++++++++++-----
.../testsuite/25_algorithms/move/constrained.cc | 29 ++++++++++++++++++++++
.../25_algorithms/move_backward/constrained.cc | 29 ++++++++++++++++++++++
3 files changed, 78 insertions(+), 6 deletions(-)
diff --git a/libstdc++-v3/include/bits/ranges_algobase.h
b/libstdc++-v3/include/bits/ranges_algobase.h
index a578bdb6fc5f..a013de40318e 100644
--- a/libstdc++-v3/include/bits/ranges_algobase.h
+++ b/libstdc++-v3/include/bits/ranges_algobase.h
@@ -165,6 +165,20 @@ namespace ranges
inline constexpr __equal_fn equal{};
+namespace __detail
+{
+ template<bool _IsMove, typename _OutIter, typename _InIter>
+ [[__gnu__::__always_inline__]]
+ constexpr void
+ __assign_one(_OutIter& __out, _InIter& __in)
+ {
+ if constexpr (_IsMove)
+ *__out = ranges::iter_move(__in);
+ else
+ *__out = *__in;
+ }
+} // namespace __detail
+
template<typename _Iter, typename _Out>
struct in_out_result
{
@@ -268,14 +282,14 @@ namespace ranges
__builtin_memmove(__result, __first,
sizeof(_ValueTypeI) * __num);
else if (__num == 1)
- std::__assign_one<_IsMove>(__result, __first);
+ __detail::__assign_one<_IsMove>(__result, __first);
return {__first + __num, __result + __num};
}
}
for (auto __n = __last - __first; __n > 0; --__n)
{
- std::__assign_one<_IsMove>(__result, __first);
+ __detail::__assign_one<_IsMove>(__result, __first);
++__first;
++__result;
}
@@ -285,7 +299,7 @@ namespace ranges
{
while (__first != __last)
{
- std::__assign_one<_IsMove>(__result, __first);
+ __detail::__assign_one<_IsMove>(__result, __first);
++__first;
++__result;
}
@@ -397,7 +411,7 @@ namespace ranges
__builtin_memmove(__result, __first,
sizeof(_ValueTypeI) * __num);
else if (__num == 1)
- std::__assign_one<_IsMove>(__result, __first);
+ __detail::__assign_one<_IsMove>(__result, __first);
return {__first + __num, __result};
}
}
@@ -409,7 +423,7 @@ namespace ranges
{
--__tail;
--__result;
- std::__assign_one<_IsMove>(__result, __tail);
+ __detail::__assign_one<_IsMove>(__result, __tail);
}
return {std::move(__lasti), std::move(__result)};
}
@@ -422,7 +436,7 @@ namespace ranges
{
--__tail;
--__result;
- std::__assign_one<_IsMove>(__result, __tail);
+ __detail::__assign_one<_IsMove>(__result, __tail);
}
return {std::move(__lasti), std::move(__result)};
}
diff --git a/libstdc++-v3/testsuite/25_algorithms/move/constrained.cc
b/libstdc++-v3/testsuite/25_algorithms/move/constrained.cc
index 096f3c6e594b..d8ed8857bb39 100644
--- a/libstdc++-v3/testsuite/25_algorithms/move/constrained.cc
+++ b/libstdc++-v3/testsuite/25_algorithms/move/constrained.cc
@@ -204,6 +204,35 @@ test05()
VERIFY( ranges::equal(v, (int[]){1,2,3,0}) );
}
+namespace pr105609
+{
+ struct I {
+ using value_type = int;
+ using difference_type = std::ptrdiff_t;
+ int operator*() const;
+ I& operator++();
+ I operator++(int);
+ I& operator--();
+ I operator--(int);
+ bool operator==(I) const;
+ friend int& iter_move(const I&);
+ };
+}
+
+void
+test06(pr105609::I i)
+{
+ // PR libstdc++/105609
+ // ranges::move should use ranges::iter_move instead of std::move
+ struct O {
+ O(int&) { }
+ O(int&&) = delete;
+ };
+
+ O* o = nullptr;
+ std::ranges::move(i, i, o);
+}
+
int
main()
{
diff --git a/libstdc++-v3/testsuite/25_algorithms/move_backward/constrained.cc
b/libstdc++-v3/testsuite/25_algorithms/move_backward/constrained.cc
index 3ad5d566ec9e..4cdac6a3a480 100644
--- a/libstdc++-v3/testsuite/25_algorithms/move_backward/constrained.cc
+++ b/libstdc++-v3/testsuite/25_algorithms/move_backward/constrained.cc
@@ -160,6 +160,35 @@ test03()
return ok;
}
+namespace pr105609
+{
+ struct I {
+ using value_type = int;
+ using difference_type = std::ptrdiff_t;
+ int operator*() const;
+ I& operator++();
+ I operator++(int);
+ I& operator--();
+ I operator--(int);
+ bool operator==(I) const;
+ friend int& iter_move(const I&);
+ };
+}
+
+void
+test04(pr105609::I i)
+{
+ // PR libstdc++/105609
+ // ranges::move should use ranges::iter_move instead of std::move
+ struct O {
+ O(int&) { }
+ O(int&&) = delete;
+ };
+
+ O* o = nullptr;
+ std::ranges::move_backward(i, i, o);
+}
+
int
main()
{
