* Try using `std::hash<std::type_index>`, `std::equal_to<std::type_index>` everywhere.
From PR #4316 we know that types in the unnamed namespace in different translation units do not compare equal, as desired.
But do types in named namespaces compare equal, as desired?
* Revert "Try using `std::hash<std::type_index>`, `std::equal_to<std::type_index>` everywhere."
This reverts commit a06949a926.
* Use "our own name-based hash and equality functions" for `std::type_index` only under macOS, based on results shown under https://github.com/pybind/pybind11/pull/4316#issuecomment-1305097879
* Patch in PR #4313: Minimal reproducer for clash when binding types defined in the unnamed namespace.
* test_unnamed_namespace_b xfail for clang
* `PYBIND11_INTERNALS_VERSION 5`
* Add a note to docs/classes.rst
* For compatibility with Google-internal testing, test_unnamed_namespace_a & test_unnamed_namespace_b need to work when imported in any order.
* Trying "__GLIBCXX__ or Windows", based on observations from Google-internal testing.
* Try _LIBCPP_VERSION
* Account for libc++ behavior in tests and documentation.
* Adjust expectations for Windows Clang (and make code less redundant).
* Add WindowsClang to ci.yml
Added block transferred from PR #4321
* Add clang-latest to name that appears in the GitHub Actions web view.
* Tweak the note in classes.rst again.
* Add `pip install --upgrade pip`, Show env, cosmetic changes
Already tested under PR #4321
* Add macos_brew_install_llvm to ci.yml
Added block transferred from PR #4324
* `test_cross_module_exception_translator` xfail 'Homebrew Clang'
* Revert back to base version of .github/workflows/ci.yml (the ci.yml changes were merged under #4323 and #4326)
* Fixes for ruff
* Make updated condition in internals.h dependent on ABI version.
* Remove PYBIND11_TEST_OVERRIDE when testing with PYBIND11_INTERNALS_VERSION=10000000
* Selectively exercise cmake `-DPYBIND11_TEST_OVERRIDE`: ubuntu, macos, windows
Extra work added to quick jobs, based on timings below, to not increase the GHA start-to-last-job-finished time.
```
Duration
^ Number of pytest runs
^ ^ Job identifier
^ ^ ^
0:03:48.024227 1 1___3___Clang_3.6___C++11___x64.txt
0:03:58.992814 1 2___3___Clang_3.7___C++11___x64.txt
0:04:25.758942 1 1___3.7___Debian___x86____Install.txt
0:04:50.148276 1 4___3___Clang_7___C++11___x64.txt
0:04:55.784558 1 13___3___Clang_15___C++20___x64.txt
0:04:57.048754 1 6___3___Clang_dev___C++11___x64.txt
0:05:00.485181 1 7___3___Clang_5___C++14___x64.txt
0:05:03.744964 1 2___3___almalinux8___x64.txt
0:05:06.222752 1 5___3___Clang_9___C++11___x64.txt
0:05:11.767022 1 2___3___GCC_7___C++17__x64.txt
0:05:18.634930 1 2___3.11__deadsnakes____x64.txt
0:05:22.810995 1 1___3___GCC_7___C++11__x64.txt
0:05:25.275317 1 12___3___Clang_14___C++20___x64.txt
0:05:32.058174 1 5___3___GCC_10___C++17__x64.txt
0:05:39.381351 1 7___3___GCC_12___C++20__x64.txt
0:05:40.502252 1 8___3___Clang_10___C++17___x64.txt
0:05:59.344905 1 3___3___Clang_3.9___C++11___x64.txt
0:06:10.825147 1 6___3___GCC_11___C++20__x64.txt
0:06:20.655443 1 3___3___almalinux9___x64.txt
0:06:22.472061 1 3___3___GCC_8___C++14__x64.txt
0:06:42.647406 1 11___3___Clang_13___C++20___x64.txt
0:06:53.352720 1 1___3.10___CUDA_11.7___Ubuntu_22.04.txt
0:07:07.357801 1 2___3.7___MSVC_2019___x86_-DCMAKE_CXX_STANDARD=14.txt
0:07:09.057603 1 1___3___centos7___x64.txt
0:07:15.546282 1 1___3.8___MSVC_2019__Debug____x86_-DCMAKE_CXX_STANDARD=17.txt
0:07:22.566022 1 4___3___GCC_8___C++17__x64.txt
0:08:13.592674 1 2___3.9___MSVC_2019__Debug____x86_-DCMAKE_CXX_STANDARD=20.txt
0:08:16.422768 1 9___3___Clang_11___C++20___x64.txt
0:08:21.168457 1 3___3.8___MSVC_2019___x86_-DCMAKE_CXX_STANDARD=17.txt
0:08:27.129468 1 10___3___Clang_12___C++20___x64.txt
0:09:35.045470 1 1___3.10___windows-latest___clang-latest.txt
0:09:57.361843 1 1___3.9___MSVC_2022_C++20___x64.txt
0:10:35.187767 1 1___3.6___MSVC_2019___x86.txt
0:11:14.691200 4 2___3.9___ubuntu-20.04___x64.txt
0:11:37.701167 1 1_macos-latest___brew_install_llvm.txt
0:11:38.688299 4 4___3.11___ubuntu-20.04___x64.txt
0:11:52.720216 1 4___3.9___MSVC_2019___x86_-DCMAKE_CXX_STANDARD=20.txt
0:13:23.456591 4 6___pypy-3.8___ubuntu-20.04___x64_-DPYBIND11_FINDPYTHON=ON.txt
0:13:25.863592 2 1___3___ICC_latest___x64.txt
0:13:32.411758 3 9___3.9___windows-2022___x64.txt
0:13:45.473377 4 3___3.10___ubuntu-20.04___x64.txt
0:13:55.366447 4 5___pypy-3.7___ubuntu-20.04___x64.txt
0:13:57.969502 3 10___3.10___windows-2022___x64.txt
0:14:19.837475 3 11___3.11___windows-2022___x64.txt
0:14:33.316770 4 1___3.6___ubuntu-20.04___x64_-DPYBIND11_FINDPYTHON=ON_-DCMA.txt
0:15:34.449278 4 22___3.6___windows-2019___x64_-DPYBIND11_FINDPYTHON=ON.txt
0:16:25.189055 2 1___3.9-dbg__deadsnakes____Valgrind___x64.txt
0:17:20.956667 4 15___3.6___macos-latest___x64.txt
0:17:27.513891 4 23___3.9___windows-2019___x64.txt
0:17:58.783286 3 8___3.6___windows-2022___x64.txt
0:18:25.917828 4 7___pypy-3.9___ubuntu-20.04___x64.txt
0:19:17.399820 3 13___pypy-3.8___windows-2022___x64.txt
0:19:45.002122 3 12___pypy-3.7___windows-2022___x64.txt
0:20:03.201926 4 16___3.9___macos-latest___x64.txt
0:20:15.415178 4 17___3.10___macos-latest___x64.txt
0:20:20.263216 4 20___pypy-3.8___macos-latest___x64.txt
0:20:31.998226 3 1___3___windows-latest___mingw64.txt
0:20:40.812286 4 18___3.11___macos-latest___x64.txt
0:22:47.714749 4 19___pypy-3.7___macos-latest___x64.txt
0:23:04.435859 3 2___3___windows-latest___mingw32.txt
0:25:48.719597 3 14___pypy-3.9___windows-2022___x64.txt
0:26:01.211688 4 21___pypy-3.9___macos-latest___x64.txt
0:28:19.971015 1 1___3___CentOS7__PGI_22.9___x64.txt
```
* Update skipif for Python 3.12a7 (the WIP needs to be handled in a separate PR).
* Introduce `get_python_state_dict()`
* Conditional version bump for Python 3.12+
* Shuffle subexpressions to make the condition easier to understand (no change to logic).
* Make pybind11 ABI version 5 the minimum for Python 3.12+ (as suggested by @Lalaland)
* Add back condition for PYPY_VERSION, but keep it open for future PyPy versions.
* Fall back to simple `|| defined(PYPY_VERSION)`. `PY_VERSION_HEX` does not appear to be meaningful with PyPy.
Without this, it's impossible to get feature parity between detection
mechanisms. Both the pkg-config file and the cmake config set their
versions, but the python probe script didn't provide an option for this.
So you could print the compiler flags for using it, but you could not
check what you got.
```
flake8...................................................................Failed
- hook id: flake8
- exit code: 1
pybind11/setup_helpers.py:177:13: B028 No explicit stacklevel keyword argument found. The warn method from the warnings module uses a stacklevel of 1 by default. This will only show a stack trace for the line on which the warn method is called. It is therefore recommended to use a stacklevel of 2 or greater to provide more information to the user.
warnings.warn("You cannot safely change the cxx_level after setting it!")
^
```
