https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89624
--- Comment #5 from Jonathan Wakely <redi at gcc dot gnu.org> ---
I think we should just do this:
--- a/libstdc++-v3/include/bits/atomic_base.h
+++ b/libstdc++-v3/include/bits/atomic_base.h
@@ -77,7 +77,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
inline constexpr memory_order memory_order_acq_rel = memory_order::acq_rel;
inline constexpr memory_order memory_order_seq_cst = memory_order::seq_cst;
#else
- typedef enum memory_order
+ enum memory_order : int
{
memory_order_relaxed,
memory_order_consume,
@@ -85,7 +85,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
memory_order_release,
memory_order_acq_rel,
memory_order_seq_cst
- } memory_order;
+ };
#endif
/// @cond undocumented
That ensures a consistent underlying type for C++17 down and C++20 up (and gets
rid of the redundant typedef). This will mean the type isn't affected by the
-fshort-enums flag at all, which also happens to solve the static_assert
failure in comment 0.
This is an ABI change for the underlying type when using -fshort-enums, but
that flag is already explicitly ABI-changing and not the default, so I care
less about a change there.
