Hello, On 27/02/2025 15:34, Jonathan Wakely wrote:
On 26/02/25 17:27 +0100, Giuseppe D'Angelo wrote:On 26/02/2025 16:33, Giuseppe D'Angelo wrote:Whops, sorry, missed this sub-thread (while replying to the other one). Change of plans then, I'll amend and remove the ad-hoc constexpr macro.Done, v3 attached. Thanks, -- Giuseppe D'AngeloFrom de3751a38330f508be9f08b77136a31481018828 Mon Sep 17 00:00:00 2001 From: Giuseppe D'Angelo <giuseppe.dang...@kdab.com> Date: Sun, 16 Feb 2025 19:37:07 +0100 Subject: [PATCH] libstdc++: implement constexpr memory algorithms This commit adds support for C++26's constexpr specialized memory algorithms, introduced by P2283R2, P3508R0, P3369R0. The uninitialized_default, value, copy, move and fill algorithms are affected, in all of their variants (iterator-based, range-based and _n versions.) The changes are mostly mechanical -- add `constexpr` to a number of signatures when compiling in C++26 and above modes. The internal helper guard class for range algorithms instead can be marked unconditionally. The only "real" change to the implementation of the algorithms is that during constant evaluation I need to dispatch to a constexpr-friendly version of them. For each algorithm family I've added only one test to cover it and its variants; the idea is to avoid too much repetition and simplify future maintenance.The patch itself looks good, but I have some comments on the ChangeLog part.
I'm adding a v4 because I discovered that one more tweak was necessary to an existing test of the <memory> header synopsis...
These are thigns I would have tweaked myself before pushing, but
now that you have commit access ...libstdc++-v3/ChangeLog: * include/bits/ranges_uninitialized.h: Mark the specialized memory algorithms as constexpr in C++26. Also mark the members of the _DestroyGuard helper class. * include/bits/stl_uninitialized.h: Ditto. * include/bits/stl_construct.h: Mark _Construct_novalue (which uses placement new to do default initialization) as constexpr in C++26. This is possible due to P2747R2, which GCC already implements; other compilers in C++26 modes already implement P2448R2, so there should be no issues there.Per-file ChangeLog entries should say "what, not why" ... for reasons.
The best reasons :)
That makes old GNU-style ChangeLog files sometimes not very useful. But at least we now have Git commit messages where we can put all the detailed background, rationale etc. So the explanation that it's possible to make it constexpr due to P2448R2 should be above in the free text part of the commit message above, along with the parenthesis saying what the function does. Also, please mention the changed function by name, i.e. * include/bits/stl_construct.h (_Construct_novalue): Mark constexpr for C++26. See https://www.gnu.org/prep/standards/html_node/Style-of-Change-Logs.html for the format. For the changes in ranges_uninitialized.h and stl_uninitialized.h it's basically "all the functions" so I think it's OK not to name them all. (It would also be OK if you did name them all individually, but I don't think it's necessary.)* include/bits/version.def: Bump the feature-testing macro.Please mention which macro, e.g. something like: * include/bits/version.def (raw_memory_algorithms): Bump value.* include/bits/version.h: Regenerate.(No need to mention the specific macro by name here, because the whole file was regenerated so this is fine.)* testsuite/20_util/specialized_algorithms/feature_test_macro.cc: New test.Please add a line break after the colon here (and the lines below). We try to keep ChangeLog entries below about 78 columns, but for libstdc++ tests that's often impossible because the pathname is already longer than that! But we can still put the "New test." on a new line.
The contrib/mklog.py script has a maximum column width of 100, should it be amended to 78? (I think that's what happened here, the script generated the overlong line and I didn't touch it.)
Feel free to push to trunk with those changes to the ChangeLog lines (and add Reviewed-by: tags for me and/or Patrick if you like). If you'd feel more comfortable sending it to the mailing list again for a final check, that's fine too. Either way, the traditional first commit when you've got write after approval access is to add yourself to the MAINTAINERS file, as per: https://gcc.gnu.org/gitwrite.html#authenticated If you add yourself to the DCO section at the end of the file, you can omit the Signed-off-by: line in future commit messages (it's implied if your name is in that section of the MAINTAINERS file).
Done, thank you again for all of the guidance. -- Giuseppe D'Angelo
From 7dc79e8f5e76810cc2123b1004e13961be940517 Mon Sep 17 00:00:00 2001
From: Giuseppe D'Angelo <giuseppe.dang...@kdab.com>
Date: Sun, 16 Feb 2025 19:37:07 +0100
Subject: [PATCH] libstdc++: implement constexpr memory algorithms
This commit adds support for C++26's constexpr specialized memory
algorithms, introduced by P2283R2, P3508R0, P3369R0.
The uninitialized_default, value, copy, move and fill algorithms are
affected, in all of their variants (iterator-based, range-based and _n
versions.)
The changes are mostly mechanical -- add `constexpr` to a number of
signatures when compiling in C++26 and above modes. The internal helper
guard class for range algorithms instead can be marked unconditionally.
uninitialized_default_construct is implemented in terms of the
_Construct_novalue helper, which requires support for C++26's constexpr
placement new from the compiler (P2747R2, which GCC implements). We can
simply mark it as constexpr in C++26 language modes, even if the
compiler does not support P2747R2 (e.g. Clang 17/18), because C++23's
P2448R2 makes it OK to mark functions as constexpr even if they never
qualify, and other compilers implement this.
The only "real" change to the implementation of the algorithms is that
during constant evaluation I need to dispatch to a constexpr-friendly
version of them.
For each algorithm family I've added only one test to cover it and its
variants; the idea is to avoid too much repetition and simplify future
maintenance.
libstdc++-v3/ChangeLog:
* include/bits/ranges_uninitialized.h: Mark the specialized
memory algorithms as constexpr in C++26. Also mark the members
of the _DestroyGuard helper class.
* include/bits/stl_uninitialized.h: Ditto.
* include/bits/stl_construct.h: (_Construct_novalue) Mark it
as constexpr in C++26.
* include/bits/version.def (raw_memory_algorithms): Bump the
feature-testing macro for C++26.
* include/bits/version.h: Regenerate.
* testsuite/20_util/headers/memory/synopsis.cc: Add constexpr to
the uninitialized_* algorithms (when in C++26) in the test.
* testsuite/20_util/specialized_algorithms/feature_test_macro.cc:
New test.
* testsuite/20_util/specialized_algorithms/uninitialized_copy/constexpr.cc:
New test.
* testsuite/20_util/specialized_algorithms/uninitialized_default_construct/constexpr.cc:
New test.
* testsuite/20_util/specialized_algorithms/uninitialized_fill/constexpr.cc:
New test.
* testsuite/20_util/specialized_algorithms/uninitialized_move/constexpr.cc:
New test.
* testsuite/20_util/specialized_algorithms/uninitialized_value_construct/constexpr.cc:
New test.
Signed-off-by: Giuseppe D'Angelo <giuseppe.dang...@kdab.com>
---
.../include/bits/ranges_uninitialized.h | 21 ++++++
libstdc++-v3/include/bits/stl_construct.h | 1 +
libstdc++-v3/include/bits/stl_uninitialized.h | 39 +++++++++++
libstdc++-v3/include/bits/version.def | 5 ++
libstdc++-v3/include/bits/version.h | 7 +-
.../20_util/headers/memory/synopsis.cc | 12 ++++
.../feature_test_macro.cc | 14 ++++
.../uninitialized_copy/constexpr.cc | 58 ++++++++++++++++
.../constexpr.cc | 67 ++++++++++++++++++
.../uninitialized_fill/constexpr.cc | 68 +++++++++++++++++++
.../uninitialized_move/constexpr.cc | 51 ++++++++++++++
.../constexpr.cc | 64 +++++++++++++++++
12 files changed, 406 insertions(+), 1 deletion(-)
create mode 100644 libstdc++-v3/testsuite/20_util/specialized_algorithms/feature_test_macro.cc
create mode 100644 libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_copy/constexpr.cc
create mode 100644 libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_default_construct/constexpr.cc
create mode 100644 libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_fill/constexpr.cc
create mode 100644 libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_move/constexpr.cc
create mode 100644 libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_value_construct/constexpr.cc
diff --git a/libstdc++-v3/include/bits/ranges_uninitialized.h b/libstdc++-v3/include/bits/ranges_uninitialized.h
index ced7bda5e37..990929efaa9 100644
--- a/libstdc++-v3/include/bits/ranges_uninitialized.h
+++ b/libstdc++-v3/include/bits/ranges_uninitialized.h
@@ -105,15 +105,18 @@ namespace ranges
const _Iter* _M_cur;
public:
+ constexpr
explicit
_DestroyGuard(const _Iter& __iter)
: _M_first(__iter), _M_cur(std::__addressof(__iter))
{ }
+ constexpr
void
release() noexcept
{ _M_cur = nullptr; }
+ constexpr
~_DestroyGuard()
{
if (_M_cur != nullptr)
@@ -126,10 +129,12 @@ namespace ranges
&& is_trivially_destructible_v<iter_value_t<_Iter>>
struct _DestroyGuard<_Iter>
{
+ constexpr
explicit
_DestroyGuard(const _Iter&)
{ }
+ constexpr
void
release() noexcept
{ }
@@ -141,6 +146,7 @@ namespace ranges
template<__detail::__nothrow_forward_iterator _Iter,
__detail::__nothrow_sentinel<_Iter> _Sent>
requires default_initializable<iter_value_t<_Iter>>
+ _GLIBCXX26_CONSTEXPR
_Iter
operator()(_Iter __first, _Sent __last) const
{
@@ -159,6 +165,7 @@ namespace ranges
template<__detail::__nothrow_forward_range _Range>
requires default_initializable<range_value_t<_Range>>
+ _GLIBCXX26_CONSTEXPR
borrowed_iterator_t<_Range>
operator()(_Range&& __r) const
{
@@ -173,6 +180,7 @@ namespace ranges
{
template<__detail::__nothrow_forward_iterator _Iter>
requires default_initializable<iter_value_t<_Iter>>
+ _GLIBCXX26_CONSTEXPR
_Iter
operator()(_Iter __first, iter_difference_t<_Iter> __n) const
{
@@ -198,6 +206,7 @@ namespace ranges
template<__detail::__nothrow_forward_iterator _Iter,
__detail::__nothrow_sentinel<_Iter> _Sent>
requires default_initializable<iter_value_t<_Iter>>
+ _GLIBCXX26_CONSTEXPR
_Iter
operator()(_Iter __first, _Sent __last) const
{
@@ -217,6 +226,7 @@ namespace ranges
template<__detail::__nothrow_forward_range _Range>
requires default_initializable<range_value_t<_Range>>
+ _GLIBCXX26_CONSTEXPR
borrowed_iterator_t<_Range>
operator()(_Range&& __r) const
{
@@ -231,6 +241,7 @@ namespace ranges
{
template<__detail::__nothrow_forward_iterator _Iter>
requires default_initializable<iter_value_t<_Iter>>
+ _GLIBCXX26_CONSTEXPR
_Iter
operator()(_Iter __first, iter_difference_t<_Iter> __n) const
{
@@ -261,6 +272,7 @@ namespace ranges
__detail::__nothrow_forward_iterator _Out,
__detail::__nothrow_sentinel<_Out> _OSent>
requires constructible_from<iter_value_t<_Out>, iter_reference_t<_Iter>>
+ _GLIBCXX26_CONSTEXPR
uninitialized_copy_result<_Iter, _Out>
operator()(_Iter __ifirst, _ISent __ilast,
_Out __ofirst, _OSent __olast) const
@@ -292,6 +304,7 @@ namespace ranges
template<input_range _IRange, __detail::__nothrow_forward_range _ORange>
requires constructible_from<range_value_t<_ORange>,
range_reference_t<_IRange>>
+ _GLIBCXX26_CONSTEXPR
uninitialized_copy_result<borrowed_iterator_t<_IRange>,
borrowed_iterator_t<_ORange>>
operator()(_IRange&& __inr, _ORange&& __outr) const
@@ -311,6 +324,7 @@ namespace ranges
template<input_iterator _Iter, __detail::__nothrow_forward_iterator _Out,
__detail::__nothrow_sentinel<_Out> _Sent>
requires constructible_from<iter_value_t<_Out>, iter_reference_t<_Iter>>
+ _GLIBCXX26_CONSTEXPR
uninitialized_copy_n_result<_Iter, _Out>
operator()(_Iter __ifirst, iter_difference_t<_Iter> __n,
_Out __ofirst, _Sent __olast) const
@@ -350,6 +364,7 @@ namespace ranges
__detail::__nothrow_sentinel<_Out> _OSent>
requires constructible_from<iter_value_t<_Out>,
iter_rvalue_reference_t<_Iter>>
+ _GLIBCXX26_CONSTEXPR
uninitialized_move_result<_Iter, _Out>
operator()(_Iter __ifirst, _ISent __ilast,
_Out __ofirst, _OSent __olast) const
@@ -384,6 +399,7 @@ namespace ranges
template<input_range _IRange, __detail::__nothrow_forward_range _ORange>
requires constructible_from<range_value_t<_ORange>,
range_rvalue_reference_t<_IRange>>
+ _GLIBCXX26_CONSTEXPR
uninitialized_move_result<borrowed_iterator_t<_IRange>,
borrowed_iterator_t<_ORange>>
operator()(_IRange&& __inr, _ORange&& __outr) const
@@ -404,6 +420,7 @@ namespace ranges
__detail::__nothrow_sentinel<_Out> _Sent>
requires constructible_from<iter_value_t<_Out>,
iter_rvalue_reference_t<_Iter>>
+ _GLIBCXX26_CONSTEXPR
uninitialized_move_n_result<_Iter, _Out>
operator()(_Iter __ifirst, iter_difference_t<_Iter> __n,
_Out __ofirst, _Sent __olast) const
@@ -441,6 +458,7 @@ namespace ranges
template<__detail::__nothrow_forward_iterator _Iter,
__detail::__nothrow_sentinel<_Iter> _Sent, typename _Tp>
requires constructible_from<iter_value_t<_Iter>, const _Tp&>
+ _GLIBCXX26_CONSTEXPR
_Iter
operator()(_Iter __first, _Sent __last, const _Tp& __x) const
{
@@ -460,6 +478,7 @@ namespace ranges
template<__detail::__nothrow_forward_range _Range, typename _Tp>
requires constructible_from<range_value_t<_Range>, const _Tp&>
+ _GLIBCXX26_CONSTEXPR
borrowed_iterator_t<_Range>
operator()(_Range&& __r, const _Tp& __x) const
{
@@ -473,6 +492,7 @@ namespace ranges
{
template<__detail::__nothrow_forward_iterator _Iter, typename _Tp>
requires constructible_from<iter_value_t<_Iter>, const _Tp&>
+ _GLIBCXX26_CONSTEXPR
_Iter
operator()(_Iter __first, iter_difference_t<_Iter> __n,
const _Tp& __x) const
@@ -573,6 +593,7 @@ namespace ranges
}
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace std
+
#endif // concepts
#endif // C++20
#endif // _RANGES_UNINITIALIZED_H
diff --git a/libstdc++-v3/include/bits/stl_construct.h b/libstdc++-v3/include/bits/stl_construct.h
index bd8235e901b..23b8fb75471 100644
--- a/libstdc++-v3/include/bits/stl_construct.h
+++ b/libstdc++-v3/include/bits/stl_construct.h
@@ -144,6 +144,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
#endif
template<typename _T1>
+ _GLIBCXX26_CONSTEXPR
inline void
_Construct_novalue(_T1* __p)
{ ::new(static_cast<void*>(__p)) _T1; }
diff --git a/libstdc++-v3/include/bits/stl_uninitialized.h b/libstdc++-v3/include/bits/stl_uninitialized.h
index ed836663a44..b1428db48b0 100644
--- a/libstdc++-v3/include/bits/stl_uninitialized.h
+++ b/libstdc++-v3/include/bits/stl_uninitialized.h
@@ -226,6 +226,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
* Like std::copy, but does not require an initialized output range.
*/
template<typename _InputIterator, typename _ForwardIterator>
+ _GLIBCXX26_CONSTEXPR
inline _ForwardIterator
uninitialized_copy(_InputIterator __first, _InputIterator __last,
_ForwardIterator __result)
@@ -256,6 +257,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
using _Src = decltype(std::__niter_base(__first));
using _ValT = typename iterator_traits<_ForwardIterator>::value_type;
+#if __glibcxx_raw_memory_algorithms >= 202411L // >= C++26
+ if consteval {
+ return std::__do_uninit_copy(__first, __last, __result);
+ }
+#endif
if constexpr (!__is_trivially_constructible(_ValT, decltype(*__first)))
return std::__do_uninit_copy(__first, __last, __result);
else if constexpr (__memcpyable<_Dest, _Src>::__value)
@@ -381,6 +387,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
* Like std::fill, but does not require an initialized output range.
*/
template<typename _ForwardIterator, typename _Tp>
+ _GLIBCXX26_CONSTEXPR
inline void
uninitialized_fill(_ForwardIterator __first, _ForwardIterator __last,
const _Tp& __x)
@@ -400,6 +407,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
#if __cplusplus >= 201103L
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wc++17-extensions"
+#if __glibcxx_raw_memory_algorithms >= 202411L // >= C++26
+ if consteval {
+ return std::__do_uninit_fill(__first, __last, __x);
+ }
+#endif
if constexpr (__is_byte<_ValueType>::__value)
if constexpr (is_same<_ValueType, _Tp>::value
|| is_integral<_Tp>::value)
@@ -509,6 +521,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
* Like std::fill_n, but does not require an initialized output range.
*/
template<typename _ForwardIterator, typename _Size, typename _Tp>
+ _GLIBCXX26_CONSTEXPR
inline _ForwardIterator
uninitialized_fill_n(_ForwardIterator __first, _Size __n, const _Tp& __x)
{
@@ -522,6 +535,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_ValueType;
#if __cplusplus >= 201103L
+#if __glibcxx_raw_memory_algorithms >= 202411L // >= C++26
+ if consteval {
+ return std::__do_uninit_fill_n(__first, __n, __x);
+ }
+#endif
if constexpr (__is_byte<_ValueType>::__value)
if constexpr (is_integral<_Tp>::value)
if constexpr (is_integral<_Size>::value)
@@ -815,6 +833,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
struct __uninitialized_default_1
{
template<typename _ForwardIterator>
+ _GLIBCXX26_CONSTEXPR
static void
__uninit_default(_ForwardIterator __first, _ForwardIterator __last)
{
@@ -829,6 +848,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
struct __uninitialized_default_1<true>
{
template<typename _ForwardIterator>
+ _GLIBCXX26_CONSTEXPR
static void
__uninit_default(_ForwardIterator __first, _ForwardIterator __last)
{
@@ -882,6 +902,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
// __uninitialized_default
// Fills [first, last) with value-initialized value_types.
template<typename _ForwardIterator>
+ _GLIBCXX26_CONSTEXPR
inline void
__uninitialized_default(_ForwardIterator __first,
_ForwardIterator __last)
@@ -979,6 +1000,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
struct __uninitialized_default_novalue_1
{
template<typename _ForwardIterator>
+ _GLIBCXX26_CONSTEXPR
static void
__uninit_default_novalue(_ForwardIterator __first,
_ForwardIterator __last)
@@ -994,6 +1016,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
struct __uninitialized_default_novalue_1<true>
{
template<typename _ForwardIterator>
+ _GLIBCXX26_CONSTEXPR
static void
__uninit_default_novalue(_ForwardIterator, _ForwardIterator)
{
@@ -1004,6 +1027,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
struct __uninitialized_default_novalue_n_1
{
template<typename _ForwardIterator, typename _Size>
+ _GLIBCXX26_CONSTEXPR
static _ForwardIterator
__uninit_default_novalue_n(_ForwardIterator __first, _Size __n)
{
@@ -1019,6 +1043,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
struct __uninitialized_default_novalue_n_1<true>
{
template<typename _ForwardIterator, typename _Size>
+ _GLIBCXX26_CONSTEXPR
static _ForwardIterator
__uninit_default_novalue_n(_ForwardIterator __first, _Size __n)
{ return std::next(__first, __n); }
@@ -1027,6 +1052,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
// __uninitialized_default_novalue
// Fills [first, last) with default-initialized value_types.
template<typename _ForwardIterator>
+ _GLIBCXX26_CONSTEXPR
inline void
__uninitialized_default_novalue(_ForwardIterator __first,
_ForwardIterator __last)
@@ -1042,6 +1068,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
// __uninitialized_default_novalue_n
// Fills [first, first + n) with default-initialized value_types.
template<typename _ForwardIterator, typename _Size>
+ _GLIBCXX26_CONSTEXPR
inline _ForwardIterator
__uninitialized_default_novalue_n(_ForwardIterator __first, _Size __n)
{
@@ -1055,6 +1082,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
template<typename _InputIterator, typename _Size,
typename _ForwardIterator>
+ _GLIBCXX26_CONSTEXPR
_ForwardIterator
__uninitialized_copy_n(_InputIterator __first, _Size __n,
_ForwardIterator __result, input_iterator_tag)
@@ -1068,6 +1096,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
template<typename _RandomAccessIterator, typename _Size,
typename _ForwardIterator>
+ _GLIBCXX26_CONSTEXPR
inline _ForwardIterator
__uninitialized_copy_n(_RandomAccessIterator __first, _Size __n,
_ForwardIterator __result,
@@ -1076,6 +1105,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
template<typename _InputIterator, typename _Size,
typename _ForwardIterator>
+ _GLIBCXX26_CONSTEXPR
pair<_InputIterator, _ForwardIterator>
__uninitialized_copy_n_pair(_InputIterator __first, _Size __n,
_ForwardIterator __result, input_iterator_tag)
@@ -1089,6 +1119,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
template<typename _RandomAccessIterator, typename _Size,
typename _ForwardIterator>
+ _GLIBCXX26_CONSTEXPR
inline pair<_RandomAccessIterator, _ForwardIterator>
__uninitialized_copy_n_pair(_RandomAccessIterator __first, _Size __n,
_ForwardIterator __result,
@@ -1112,6 +1143,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
* Like copy_n(), but does not require an initialized output range.
*/
template<typename _InputIterator, typename _Size, typename _ForwardIterator>
+ _GLIBCXX26_CONSTEXPR
inline _ForwardIterator
uninitialized_copy_n(_InputIterator __first, _Size __n,
_ForwardIterator __result)
@@ -1120,6 +1152,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
/// @cond undocumented
template<typename _InputIterator, typename _Size, typename _ForwardIterator>
+ _GLIBCXX26_CONSTEXPR
inline pair<_InputIterator, _ForwardIterator>
__uninitialized_copy_n_pair(_InputIterator __first, _Size __n,
_ForwardIterator __result)
@@ -1139,6 +1172,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
* @since C++17
*/
template <typename _ForwardIterator>
+ _GLIBCXX26_CONSTEXPR
inline void
uninitialized_default_construct(_ForwardIterator __first,
_ForwardIterator __last)
@@ -1154,6 +1188,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
* @since C++17
*/
template <typename _ForwardIterator, typename _Size>
+ _GLIBCXX26_CONSTEXPR
inline _ForwardIterator
uninitialized_default_construct_n(_ForwardIterator __first, _Size __count)
{
@@ -1167,6 +1202,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
* @since C++17
*/
template <typename _ForwardIterator>
+ _GLIBCXX26_CONSTEXPR
inline void
uninitialized_value_construct(_ForwardIterator __first,
_ForwardIterator __last)
@@ -1182,6 +1218,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
* @since C++17
*/
template <typename _ForwardIterator, typename _Size>
+ _GLIBCXX26_CONSTEXPR
inline _ForwardIterator
uninitialized_value_construct_n(_ForwardIterator __first, _Size __count)
{
@@ -1197,6 +1234,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
* @since C++17
*/
template <typename _InputIterator, typename _ForwardIterator>
+ _GLIBCXX26_CONSTEXPR
inline _ForwardIterator
uninitialized_move(_InputIterator __first, _InputIterator __last,
_ForwardIterator __result)
@@ -1215,6 +1253,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
* @since C++17
*/
template <typename _InputIterator, typename _Size, typename _ForwardIterator>
+ _GLIBCXX26_CONSTEXPR
inline pair<_InputIterator, _ForwardIterator>
uninitialized_move_n(_InputIterator __first, _Size __count,
_ForwardIterator __result)
diff --git a/libstdc++-v3/include/bits/version.def b/libstdc++-v3/include/bits/version.def
index 9b1c236d817..1e979c79d20 100644
--- a/libstdc++-v3/include/bits/version.def
+++ b/libstdc++-v3/include/bits/version.def
@@ -521,6 +521,11 @@ ftms = {
ftms = {
name = raw_memory_algorithms;
+ values = {
+ v = 202411;
+ cxxmin = 26;
+ extra_cond = "__cpp_constexpr >= 202406L";
+ };
values = {
v = 201606;
cxxmin = 17;
diff --git a/libstdc++-v3/include/bits/version.h b/libstdc++-v3/include/bits/version.h
index 92003b5365b..085309bbdfa 100644
--- a/libstdc++-v3/include/bits/version.h
+++ b/libstdc++-v3/include/bits/version.h
@@ -581,7 +581,12 @@
#undef __glibcxx_want_gcd_lcm
#if !defined(__cpp_lib_raw_memory_algorithms)
-# if (__cplusplus >= 201703L)
+# if (__cplusplus > 202302L) && (__cpp_constexpr >= 202406L)
+# define __glibcxx_raw_memory_algorithms 202411L
+# if defined(__glibcxx_want_all) || defined(__glibcxx_want_raw_memory_algorithms)
+# define __cpp_lib_raw_memory_algorithms 202411L
+# endif
+# elif (__cplusplus >= 201703L)
# define __glibcxx_raw_memory_algorithms 201606L
# if defined(__glibcxx_want_all) || defined(__glibcxx_want_raw_memory_algorithms)
# define __cpp_lib_raw_memory_algorithms 201606L
diff --git a/libstdc++-v3/testsuite/20_util/headers/memory/synopsis.cc b/libstdc++-v3/testsuite/20_util/headers/memory/synopsis.cc
index c9edfb2c0ff..450a6a7bfc6 100644
--- a/libstdc++-v3/testsuite/20_util/headers/memory/synopsis.cc
+++ b/libstdc++-v3/testsuite/20_util/headers/memory/synopsis.cc
@@ -73,18 +73,30 @@ namespace std
template <class T> T* addressof(T&) noexcept;
#endif
template <class InputIterator, class ForwardIterator>
+#if __cplusplus >= 202400L
+ constexpr
+#endif
ForwardIterator
uninitialized_copy(InputIterator first, InputIterator last,
ForwardIterator result);
#if __cplusplus >= 201103L
template <class InputIterator, class Size, class ForwardIterator>
+#if __cplusplus >= 202400L
+ constexpr
+#endif
ForwardIterator
uninitialized_copy_n(InputIterator first, Size n, ForwardIterator result);
#endif
template <class ForwardIterator, class T>
+#if __cplusplus >= 202400L
+ constexpr
+#endif
void uninitialized_fill(ForwardIterator first, ForwardIterator last,
const T& x);
template <class ForwardIterator, class Size, class T>
+#if __cplusplus >= 202400L
+ constexpr
+#endif
void uninitialized_fill_n(ForwardIterator first, Size n, const T& x);
#if __cplusplus >= 201103L
diff --git a/libstdc++-v3/testsuite/20_util/specialized_algorithms/feature_test_macro.cc b/libstdc++-v3/testsuite/20_util/specialized_algorithms/feature_test_macro.cc
new file mode 100644
index 00000000000..0252753aa66
--- /dev/null
+++ b/libstdc++-v3/testsuite/20_util/specialized_algorithms/feature_test_macro.cc
@@ -0,0 +1,14 @@
+// { dg-do compile { target c++17 } }
+// { dg-add-options no_pch }
+
+#include <memory>
+
+#ifndef __cpp_lib_raw_memory_algorithms
+# error "Feature-test macro for raw memory algorithms missing"
+#elif __cplusplus > 202302L
+# if __cpp_lib_raw_memory_algorithms < 202411L
+# error "Feature-test macro for raw memory algorithms has wrong value"
+# endif
+#elif __cpp_lib_raw_memory_algorithms < 201606L
+# error "Feature-test macro for raw memory algorithms has wrong value"
+#endif
diff --git a/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_copy/constexpr.cc b/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_copy/constexpr.cc
new file mode 100644
index 00000000000..6f05b0ce309
--- /dev/null
+++ b/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_copy/constexpr.cc
@@ -0,0 +1,58 @@
+// { dg-do compile { target c++26 } }
+
+#include <algorithm>
+#include <memory>
+#include <span>
+#include <string>
+#include <vector>
+
+template<typename T>
+constexpr
+bool
+test01_impl(std::vector<T> input)
+{
+ static_assert(std::copy_constructible<T>);
+ static_assert(std::equality_comparable<T>);
+
+ const std::size_t input_size = input.size();
+ std::allocator<T> alloc;
+ T* ptr = alloc.allocate(input_size);
+
+ std::uninitialized_copy(input.begin(), input.end(), ptr);
+ if (!std::equal(input.begin(), input.end(), ptr, ptr + input_size))
+ return false;
+ std::destroy(ptr, ptr + input_size);
+
+ std::uninitialized_copy_n(input.begin(), input_size, ptr);
+ if (!std::equal(input.begin(), input.end(), ptr, ptr + input_size))
+ return false;
+ std::destroy_n(ptr, input_size);
+
+ std::span<T> output(ptr, ptr + input_size);
+ std::ranges::uninitialized_copy(input, output);
+ if (!std::ranges::equal(input, output))
+ return false;
+ std::ranges::destroy(output);
+
+ std::ranges::uninitialized_copy_n(input.begin(), input_size, ptr, ptr + input_size);
+ if (!std::ranges::equal(input.begin(), input.end(), ptr, ptr + input_size))
+ return false;
+ std::ranges::destroy_n(ptr, input_size);
+
+ alloc.deallocate(ptr, input_size);
+ return true;
+}
+
+constexpr
+bool
+test01()
+{
+ return
+ test01_impl<char>({'a', 'b', 'c'}) &&
+ test01_impl<int>({1, 2, 3, 4}) &&
+ test01_impl<double>({1.0, 2.0, 3.0, 4.0}) &&
+ test01_impl<std::string>({"a", "b", "cc", "dddd", "eeeeeeeeeeeeeeee"}) &&
+ test01_impl<std::vector<int>>({ {0}, {0, 1}, {0, 1, 2}});
+}
+
+static_assert(test01());
diff --git a/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_default_construct/constexpr.cc b/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_default_construct/constexpr.cc
new file mode 100644
index 00000000000..db39c8b4d05
--- /dev/null
+++ b/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_default_construct/constexpr.cc
@@ -0,0 +1,67 @@
+// { dg-do compile { target c++26 } }
+
+#include <algorithm>
+#include <memory>
+#include <span>
+#include <string>
+#include <vector>
+
+template<typename T>
+constexpr
+bool
+test01_impl()
+{
+ static_assert(std::default_initializable<T>);
+ static_assert(std::equality_comparable<T>);
+
+ constexpr std::size_t size = 42;
+ std::allocator<T> alloc;
+ T* ptr = alloc.allocate(size);
+
+ auto check = [&]() -> bool
+ {
+ if constexpr (!std::is_trivially_default_constructible_v<T>)
+ return std::all_of(ptr, ptr + size, [](auto &&x) { return x == T(); });
+ else
+ return true;
+ };
+
+ std::uninitialized_default_construct(ptr, ptr + size);
+ if (!check())
+ return false;
+ std::destroy(ptr, ptr + size);
+
+ std::uninitialized_default_construct_n(ptr, size);
+ if (!check())
+ return false;
+ std::destroy_n(ptr, size);
+
+ std::span<T> storage(ptr, ptr + size);
+ std::ranges::uninitialized_default_construct(storage);
+ if (!check())
+ return false;
+ std::ranges::destroy(storage);
+
+ std::ranges::uninitialized_default_construct_n(ptr, size);
+ if (!check())
+ return false;
+ std::ranges::destroy_n(ptr, size);
+
+ alloc.deallocate(ptr, size);
+ return true;
+}
+
+constexpr
+bool
+test01()
+{
+ return
+ test01_impl<char>() &&
+ test01_impl<int>() &&
+ test01_impl<double>() &&
+ test01_impl<std::string>() &&
+ test01_impl<std::vector<int>>() &&
+ test01_impl<std::unique_ptr<int>>();
+}
+
+static_assert(test01());
diff --git a/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_fill/constexpr.cc b/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_fill/constexpr.cc
new file mode 100644
index 00000000000..e43cd35a92d
--- /dev/null
+++ b/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_fill/constexpr.cc
@@ -0,0 +1,68 @@
+// { dg-do compile { target c++26 } }
+
+#include <algorithm>
+#include <memory>
+#include <span>
+#include <string>
+#include <vector>
+
+template<typename T, typename U = T>
+constexpr
+bool
+test01_impl(const U& value = U())
+{
+ static_assert(std::constructible_from<T, U>);
+ //static_assert(std::equality_comparable_with<T, U>); // unique_ptr fails with nullptr_t
+
+ constexpr std::size_t size = 42;
+ std::allocator<T> alloc;
+ T* ptr = alloc.allocate(size);
+
+ auto check = [&]() -> bool
+ {
+ return std::all_of(ptr, ptr + size, [&](auto &&x) { return x == value; });
+ };
+
+ std::uninitialized_fill(ptr, ptr + size, value);
+ if (!check())
+ return false;
+ std::destroy(ptr, ptr + size);
+
+ std::uninitialized_fill_n(ptr, size, value);
+ if (!check())
+ return false;
+ std::destroy_n(ptr, size);
+
+ std::span<T> storage(ptr, ptr + size);
+ std::ranges::uninitialized_fill(storage, value);
+ if (!check())
+ return false;
+ std::ranges::destroy(storage);
+
+ std::ranges::uninitialized_fill_n(ptr, size, value);
+ if (!check())
+ return false;
+ std::ranges::destroy_n(ptr, size);
+
+ alloc.deallocate(ptr, size);
+ return true;
+}
+
+constexpr
+bool
+test01()
+{
+ return
+ test01_impl<char>('\0') &&
+ test01_impl<char>('x') &&
+ test01_impl<int>(0) &&
+ test01_impl<int>(42) &&
+ test01_impl<double>(3.14) &&
+ test01_impl<std::string>() &&
+ test01_impl<std::string>(std::string("test")) &&
+ test01_impl<std::vector<int>>() &&
+ test01_impl<std::vector<int>>({1, 2, 3, 4}) &&
+ test01_impl<std::unique_ptr<int>>(nullptr);
+}
+
+static_assert(test01());
diff --git a/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_move/constexpr.cc b/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_move/constexpr.cc
new file mode 100644
index 00000000000..47403ae706d
--- /dev/null
+++ b/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_move/constexpr.cc
@@ -0,0 +1,51 @@
+// { dg-do compile { target c++26 } }
+
+#include <algorithm>
+#include <memory>
+#include <span>
+#include <string>
+#include <vector>
+
+template<typename T>
+constexpr
+bool
+test01_impl(std::vector<T> input)
+{
+ static_assert(std::move_constructible<T>);
+ static_assert(std::equality_comparable<T>);
+
+ const std::size_t input_size = input.size();
+ std::allocator<T> alloc;
+ T* ptr = alloc.allocate(input_size);
+
+ std::uninitialized_move(input.begin(), input.end(), ptr);
+ std::destroy(ptr, ptr + input_size);
+
+ std::uninitialized_move_n(input.begin(), input_size, ptr);
+ std::destroy_n(ptr, input_size);
+
+ std::span<T> output(ptr, ptr + input_size);
+ std::ranges::uninitialized_move(input, output);
+ std::ranges::destroy(output);
+
+ std::ranges::uninitialized_move_n(input.begin(), input_size, ptr, ptr + input_size);
+ std::ranges::destroy_n(ptr, input_size);
+
+ alloc.deallocate(ptr, input_size);
+ return true;
+}
+
+constexpr
+bool
+test01()
+{
+ return
+ test01_impl<char>({'a', 'b', 'c'}) &&
+ test01_impl<int>({1, 2, 3, 4}) &&
+ test01_impl<double>({1.0, 2.0, 3.0, 4.0}) &&
+ test01_impl<std::string>({"a", "b", "cc", "dddd", "eeeeeeeeeeeeeeee"}) &&
+ test01_impl<std::vector<int>>({ {0}, {0, 1}, {0, 1, 2}}) &&
+ test01_impl<std::unique_ptr<int>>(std::vector<std::unique_ptr<int>>(10));
+}
+
+static_assert(test01());
diff --git a/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_value_construct/constexpr.cc b/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_value_construct/constexpr.cc
new file mode 100644
index 00000000000..55dfc59b5ef
--- /dev/null
+++ b/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_value_construct/constexpr.cc
@@ -0,0 +1,64 @@
+// { dg-do compile { target c++26 } }
+
+#include <algorithm>
+#include <memory>
+#include <span>
+#include <string>
+#include <vector>
+
+template<typename T>
+constexpr
+bool
+test01_impl()
+{
+ static_assert(std::default_initializable<T>);
+ static_assert(std::equality_comparable<T>);
+
+ constexpr std::size_t size = 42;
+ std::allocator<T> alloc;
+ T* ptr = alloc.allocate(size);
+
+ auto check = [&]() -> bool
+ {
+ return std::all_of(ptr, ptr + size, [](auto &&x) { return x == T(); });
+ };
+
+ std::uninitialized_value_construct(ptr, ptr + size);
+ if (!check())
+ return false;
+ std::destroy(ptr, ptr + size);
+
+ std::uninitialized_value_construct_n(ptr, size);
+ if (!check())
+ return false;
+ std::destroy_n(ptr, size);
+
+ std::span<T> storage(ptr, ptr + size);
+ std::ranges::uninitialized_value_construct(storage);
+ if (!check())
+ return false;
+ std::ranges::destroy(storage);
+
+ std::ranges::uninitialized_value_construct_n(ptr, size);
+ if (!check())
+ return false;
+ std::ranges::destroy_n(ptr, size);
+
+ alloc.deallocate(ptr, size);
+ return true;
+}
+
+constexpr
+bool
+test01()
+{
+ return
+ test01_impl<char>() &&
+ test01_impl<int>() &&
+ test01_impl<double>() &&
+ test01_impl<std::string>() &&
+ test01_impl<std::vector<int>>() &&
+ test01_impl<std::unique_ptr<int>>();
+}
+
+static_assert(test01());
--
2.34.1
smime.p7s
Description: S/MIME Cryptographic Signature
