On Sat, 28 Mar 2026, 13:50 Tomasz Kamiński, <[email protected]> wrote:
> This implements with P3936R1 Safer atomic_ref::address with
> the bump to __cpp_lib_atomic_ref feture test macro.
>
> libstdc++-v3/ChangeLog:
>
> * include/bits/atomic_base.h
> (__atomic_ref_base::_Address_return_t):
> Define.
> (__atomic_ref_base::address): Change return type to
> _Address_return_t.
> * include/bits/version.def (atomic_ref): Bump to 202503.
>
The new value should be 202603.
OK with that change.
* include/bits/version.h: Regenerate.
> * testsuite/29_atomics/atomic_ref/address.cc: Update check for
> return type.
> ---
> Tested *atomic_ref* on x86_64-linux.
> OK for trunk when full testsuite passes?
>
> libstdc++-v3/include/bits/atomic_base.h | 10 ++++++++--
> libstdc++-v3/include/bits/version.def | 2 +-
> libstdc++-v3/include/bits/version.h | 4 ++--
> .../testsuite/29_atomics/atomic_ref/address.cc | 12 ++++++------
> 4 files changed, 17 insertions(+), 11 deletions(-)
>
> diff --git a/libstdc++-v3/include/bits/atomic_base.h
> b/libstdc++-v3/include/bits/atomic_base.h
> index 6c5b83a0818..62970108ea6 100644
> --- a/libstdc++-v3/include/bits/atomic_base.h
> +++ b/libstdc++-v3/include/bits/atomic_base.h
> @@ -1649,6 +1649,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> {
> private:
> using _Vt = remove_cv_t<_Tp>;
> + using _Address_return_t = __conditional_t<is_volatile_v<_Tp>,
> + const volatile void*,
> const void*>;
>
> static consteval bool
> _S_is_always_lock_free()
> @@ -1714,7 +1716,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> #endif // __glibcxx_atomic_wait
>
> #if __glibcxx_atomic_ref >= 202411L
> - _GLIBCXX_ALWAYS_INLINE constexpr const _Tp*
> + _GLIBCXX_ALWAYS_INLINE constexpr const _Address_return_t
> address() const noexcept
> { return _M_ptr; }
> #endif // __glibcxx_atomic_ref >= 202411L
> @@ -1727,6 +1729,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> struct __atomic_ref_base
> : __atomic_ref_base<const _Tp>
> {
> + using _Address_return_t = __conditional_t<is_volatile_v<_Tp>,
> + volatile void*, void*>;
> +
> + public:
> using value_type = typename __atomic_ref_base<const
> _Tp>::value_type;
>
> explicit
> @@ -1807,7 +1813,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> #endif // __glibcxx_atomic_wait
>
> #if __glibcxx_atomic_ref >= 202411L
> - _GLIBCXX_ALWAYS_INLINE constexpr _Tp*
> + _GLIBCXX_ALWAYS_INLINE constexpr _Address_return_t
> address() const noexcept
> { return this->_M_ptr; }
> #endif // __glibcxx_atomic_ref >= 202411L
> diff --git a/libstdc++-v3/include/bits/version.def
> b/libstdc++-v3/include/bits/version.def
> index dd77524b5a9..5aaf1550829 100644
> --- a/libstdc++-v3/include/bits/version.def
> +++ b/libstdc++-v3/include/bits/version.def
> @@ -817,7 +817,7 @@ ftms = {
> ftms = {
> name = atomic_ref;
> values = {
> - v = 202411;
> + v = 202503;
> cxxmin = 26;
> };
> values = {
> diff --git a/libstdc++-v3/include/bits/version.h
> b/libstdc++-v3/include/bits/version.h
> index bef61baeba8..ed1f0028691 100644
> --- a/libstdc++-v3/include/bits/version.h
> +++ b/libstdc++-v3/include/bits/version.h
> @@ -910,9 +910,9 @@
>
> #if !defined(__cpp_lib_atomic_ref)
> # if (__cplusplus > 202302L)
> -# define __glibcxx_atomic_ref 202411L
> +# define __glibcxx_atomic_ref 202503L
> # if defined(__glibcxx_want_all) || defined(__glibcxx_want_atomic_ref)
> -# define __cpp_lib_atomic_ref 202411L
> +# define __cpp_lib_atomic_ref 202503L
> # endif
> # elif (__cplusplus >= 202002L)
> # define __glibcxx_atomic_ref 201806L
> diff --git a/libstdc++-v3/testsuite/29_atomics/atomic_ref/address.cc
> b/libstdc++-v3/testsuite/29_atomics/atomic_ref/address.cc
> index e2eda506efa..d4bb500185e 100644
> --- a/libstdc++-v3/testsuite/29_atomics/atomic_ref/address.cc
> +++ b/libstdc++-v3/testsuite/29_atomics/atomic_ref/address.cc
> @@ -8,26 +8,26 @@
>
> #include <testsuite_hooks.h>
>
> -template <typename T>
> +template <typename T, typename CVV>
> void testAtomicRefAddress()
> {
> T x(T(42));
> const std::atomic_ref<T> a(x);
>
> static_assert( noexcept(a.address()) );
> - static_assert( std::is_same_v<decltype(a.address()), T*> );
> + static_assert( std::is_same_v<decltype(a.address()), CVV*> );
> VERIFY( std::addressof(x) == a.address() );
> }
>
> template <typename T>
> void testAtomicRefAddressForCV()
> {
> - testAtomicRefAddress<T>();
> - testAtomicRefAddress<const T>();
> + testAtomicRefAddress<T, void>();
> + testAtomicRefAddress<const T, const void>();
> if constexpr (std::atomic_ref<T>::is_always_lock_free)
> {
> - testAtomicRefAddress<volatile T>();
> - testAtomicRefAddress<const volatile T>();
> + testAtomicRefAddress<volatile T, volatile void>();
> + testAtomicRefAddress<const volatile T, const volatile void>();
> }
> }
>
> --
> 2.53.0
>
>
