[libcxx-commits] [libcxx] [libcxx] adds a size-based representation for `vector`'s unstable ABI (PR #155330)

[Christopher Di Bella via libcxx-commits]

================
@@ -316,9 +314,9 @@ public:
   }
 
   _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __swap_without_allocator(
-      __split_buffer_pointer_layout<__split_buffer<value_type, __alloc_rr&, __split_buffer_pointer_layout>,
-                                    value_type,
-                                    __alloc_rr&>& __other) _NOEXCEPT {
+      __split_buffer_size_layout<__split_buffer<value_type, __alloc_rr&, __split_buffer_size_layout>,
----------------
cjdb wrote:

Yes, this was a bug-fix. We don't have a way to test that `__split_buffer` works with `__split_buffer_size_layout` without size-based vector (which is its only driver), so I'm kind of ambivalent on whether this happens in lock-step with vector or if it happens in a separate PR.

Again, the benefit of another commit is that it adds documentation, so I'm partial on that front.

https://github.com/llvm/llvm-project/pull/155330