[libcxx-commits] [libcxx] [libc++][chrono] Remove non-standard relational operators for `std::chrono::weekday` (PR #98730)

[A. Jiang via libcxx-commits]

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@@ -134,6 +134,12 @@ Deprecations and Removals
   `std-allocator-const <https://clang.llvm.org/extra/clang-tidy/checks/portability/std-allocator-const.html>`
   enabled.
 
+- libc++ no longer supports relational comparison for ``std::chrono::weekday``. The relational comparison operators were
+  provided as an undocumented extension. If you were using relational comparison on ``std::chrono::weekday``, compare
+  the results of ``c_encoding()`` or ``iso_encoding()`` instead. The
+  ``_LIBCPP_ENABLE_REMOVED_WEEKDAY_RELATIONAL_OPERATORS`` macro can be defined to temporarily re-enable this extension.
+  This macro will be honored for one release and ignored starting in LLVM 20.
+
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frederick-vs-ja wrote:

Done. It seems that `20.rst` should also be updated so I also added an entry inside it.

https://github.com/llvm/llvm-project/pull/98730