…erywhere **except when libc++ is in use** (#4319)

* 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 a06949a9265014b3c581396c4f37c45ccc03dea6.

* Use "our own name-based hash and equality functions" for `std::type_index` only under macOS, based on results shown under pybind/pybind11#4316 (comment)

* 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).

…641)

* chore(deps): update pre-commit hooks

updates:
- [github.com/psf/black: 23.1.0 → 23.3.0](psf/black@23.1.0...23.3.0)
- [github.com/Lucas-C/pre-commit-hooks: v1.4.2 → v1.5.1](Lucas-C/pre-commit-hooks@v1.4.2...v1.5.1)
- [github.com/charliermarsh/ruff-pre-commit: v0.0.254 → v0.0.260](astral-sh/ruff-pre-commit@v0.0.254...v0.0.260)
- [github.com/PyCQA/pylint: v2.16.4 → v3.0.0a6](pylint-dev/pylint@v2.16.4...v3.0.0a6)
- [github.com/pre-commit/mirrors-mypy: v1.0.1 → v1.1.1](pre-commit/mirrors-mypy@v1.0.1...v1.1.1)
- [github.com/codespell-project/codespell: v2.2.2 → v2.2.4](codespell-project/codespell@v2.2.2...v2.2.4)
- [github.com/pre-commit/mirrors-clang-format: v15.0.7 → v16.0.0](pre-commit/mirrors-clang-format@v15.0.7...v16.0.0)

* style: pre-commit fixes

* style: fix issues

* Update tests/test_call_policies.py

* Update tests/test_call_policies.py

* fix: ignore code in file

* style: pre-commit fixes

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Henry Schreiner <[email protected]>

Signed-off-by: Henry Schreiner <[email protected]>

…ythons (#4639)

* Inject -stdlib=libc++ on macOS only when it's supported, close #4637.

On macOS, by default, pybind11 currently unconditionally set the compiler
flag "-stdlib=libc++" in Pybind11Extension.__init__(), regardless of which
compiler is used. This flag is required for clang, but is invalid for GCC.
If GCC is used, it causes compilation failures in all Python projects that
use pybind11, with the error message:

    arm64-apple-darwin22-gcc: error: unrecognized command-line option -stdlib=libc++.

This commit uses has_flag() to detect whether "-stdlib=libc++" on macOS,
and injects this flag from build_ext.build_extensions(), rather than
setting it unconditionally.

Signed-off-by: Yifeng Li <[email protected]>

* revert: just remove flags

---------

Signed-off-by: Yifeng Li <[email protected]>
Co-authored-by: Henry Schreiner <[email protected]>

…650)

Bumps [pypa/gh-action-pypi-publish](https://github.com/pypa/gh-action-pypi-publish) from 1.8.5 to 1.8.6.
- [Release notes](https://github.com/pypa/gh-action-pypi-publish/releases)
- [Commits](pypa/gh-action-pypi-publish@v1.8.5...v1.8.6)

---
updated-dependencies:
- dependency-name: pypa/gh-action-pypi-publish
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

updates:
- [github.com/pre-commit/mirrors-mypy: v1.1.1 → v1.2.0](pre-commit/mirrors-mypy@v1.1.1...v1.2.0)
- [github.com/pre-commit/mirrors-clang-format: v16.0.0 → v16.0.2](pre-commit/mirrors-clang-format@v16.0.0...v16.0.2)

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

* Testing

* Similar fix for std::vector

* Fix infinite recursion check:

1) Apply to is_copy_assignable additionally
2) Check infinite recursion for map-like types

* style: pre-commit fixes

* Optional commit that demonstrates the limitations of this PR

* Fix positioning of container bindings

The bindings were previously in a block that was only activated if numpy
was available.

* Suggestions from code review: API side

* Suggestions from code review: Test side

* Suggestions from code review

1) Renaming: is_recursive_container and
   MutuallyRecursiveContainerPair(MV|VM)
2) Avoid ambiguous specializations of is_recursive_container

* Some little fixes

* Reordering of structs

* Add recursive checks for is_move_constructible

* Static testing for pybind11 type traits

* More precise checking of recursive types

Instead of a trait `is_recursive_container`, use a trait
`recursive_container_traits` with dependent type
`recursive_container_traits::type_to_check_recursively`.
So, instead of just checking if a type is recursive and then trying to
somehow deal with it, recursively-defined traits such as
is_move_constructible can now directly ask this trait where the
recursion should proceed.

* Review suggestions

1. Use std::conditional
2. Fix typo

* Remove leftover include from test

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

* Add `type_caster<PyObject>` (tests are still incomplete).

* Fix oversight (`const PyObject *`).

* Ensure `type_caster<PyObject>` only works for `PyObject *`

* Move `is_same_ignoring_cvref` into `detail` namespace.

* Add test_cast_nullptr

* Change is_same_ignoring_cvref from variable template to using.

```
test_type_caster_pyobject_ptr.cpp:8:23: error: variable templates only available with ‘-std=c++14’ or ‘-std=gnu++14’ [-Werror]
    8 | static constexpr bool is_same_ignoring_cvref = std::is_same<detail::remove_cvref_t<T>, U>::value;
      |                       ^~~~~~~~~~~~~~~~~~~~~~
```

* Remove `return_value_policy::reference_internal` `keep_alive` feature (because of doubts about it actually being useful).

* Add missing test, fix bug (missing `throw error_already_set();`), various cosmetic changes.

* Move `type_caster<PyObject>` from test to new include (pybind11/type_caster_pyobject_ptr.h)

* Add new header file to CMakeLists.txt and tests/extra_python_package/test_files.py

* Backport changes from google/pybind11clif#30021 to pybind/pybind11#4601

* Fix oversight in test (to resolve a valgrind leak detection error) and add a related comment in cast.h.

No production code changes.

Make tests more sensitive by using `ValueHolder` instead of empty tuples and dicts.

Manual leak checks with `while True:` & top command repeated for all tests.

* Add tests for interop with stl.h `list_caster`

(No production code changes.)

* Bug fix in test. Minor comment enhancements.

* Change `type_caster<PyObject>::name` to `object`, as suggested by @Skylion007

* Expand comment for the new `T cast(const handle &handle)` [`T` = `PyObject *`]

* Add `T cast(object &&obj)` overload as suggested by @Skylion007

The original suggestion leads to `error: call to 'cast' is ambiguous` (full error message below), therefore SFINAE guarding is needed.

```
clang++ -o pybind11/tests/test_type_caster_pyobject_ptr.os -c -std=c++17 -fPIC -fvisibility=hidden -O0 -g -Wall -Wextra -Wconversion -Wcast-qual -Wdeprecated -Wundef -Wnon-virtual-dtor -Wunused-result -Werror -isystem /usr/include/python3.10 -isystem /usr/include/eigen3 -DPYBIND11_STRICT_ASSERTS_CLASS_HOLDER_VS_TYPE_CASTER_MIX -DPYBIND11_ENABLE_TYPE_CASTER_ODR_GUARD_IF_AVAILABLE -DPYBIND11_TEST_BOOST -Ipybind11/include -I/usr/local/google/home/rwgk/forked/pybind11/include -I/usr/local/google/home/rwgk/clone/pybind11/include /usr/local/google/home/rwgk/forked/pybind11/tests/test_type_caster_pyobject_ptr.cpp
In file included from /usr/local/google/home/rwgk/forked/pybind11/tests/test_type_caster_pyobject_ptr.cpp:1:
In file included from /usr/local/google/home/rwgk/forked/pybind11/include/pybind11/functional.h:12:
In file included from /usr/local/google/home/rwgk/forked/pybind11/include/pybind11/pybind11.h:13:
In file included from /usr/local/google/home/rwgk/forked/pybind11/include/pybind11/detail/class.h:12:
In file included from /usr/local/google/home/rwgk/forked/pybind11/include/pybind11/attr.h:14:
/usr/local/google/home/rwgk/forked/pybind11/include/pybind11/cast.h:1165:12: error: call to 'cast' is ambiguous
    return pybind11::cast<T>(std::move(*this));
           ^~~~~~~~~~~~~~~~~
/usr/local/google/home/rwgk/forked/pybind11/include/pybind11/functional.h:109:70: note: in instantiation of function template specialization 'pybind11::object::cast<_object *>' requested here
                return hfunc.f(std::forward<Args>(args)...).template cast<Return>();
                                                                     ^
/usr/local/google/home/rwgk/forked/pybind11/include/pybind11/functional.h:103:16: note: in instantiation of member function 'pybind11::detail::type_caster<std::function<_object *(int)>>::load(pybind11::handle, bool)::func_wrapper::operator()' requested here
        struct func_wrapper {
               ^
/usr/local/google/home/rwgk/forked/pybind11/include/pybind11/cast.h:1456:47: note: in instantiation of member function 'pybind11::detail::type_caster<std::function<_object *(int)>>::load' requested here
        if ((... || !std::get<Is>(argcasters).load(call.args[Is], call.args_convert[Is]))) {
                                              ^
/usr/local/google/home/rwgk/forked/pybind11/include/pybind11/cast.h:1434:50: note: in instantiation of function template specialization 'pybind11::detail::argument_loader<const std::function<_object *(int)> &, int>::load_impl_sequence<0UL, 1UL>' requested here
    bool load_args(function_call &call) { return load_impl_sequence(call, indices{}); }
                                                 ^
/usr/local/google/home/rwgk/forked/pybind11/include/pybind11/pybind11.h:227:33: note: in instantiation of member function 'pybind11::detail::argument_loader<const std::function<_object *(int)> &, int>::load_args' requested here
            if (!args_converter.load_args(call)) {
                                ^
/usr/local/google/home/rwgk/forked/pybind11/include/pybind11/pybind11.h:101:9: note: in instantiation of function template specialization 'pybind11::cpp_function::initialize<(lambda at /usr/local/google/home/rwgk/forked/pybind11/tests/test_type_caster_pyobject_ptr.cpp:50:9), _object *, const std::function<_object *(int)> &, int, pybind11::name, pybind11::scope, pybind11::sibling, pybind11::return_value_policy>' requested here
        initialize(
        ^
/usr/local/google/home/rwgk/forked/pybind11/include/pybind11/pybind11.h:1163:22: note: in instantiation of function template specialization 'pybind11::cpp_function::cpp_function<(lambda at /usr/local/google/home/rwgk/forked/pybind11/tests/test_type_caster_pyobject_ptr.cpp:50:9), pybind11::name, pybind11::scope, pybind11::sibling, pybind11::return_value_policy, void>' requested here
        cpp_function func(std::forward<Func>(f),
                     ^
/usr/local/google/home/rwgk/forked/pybind11/tests/test_type_caster_pyobject_ptr.cpp:48:7: note: in instantiation of function template specialization 'pybind11::module_::def<(lambda at /usr/local/google/home/rwgk/forked/pybind11/tests/test_type_caster_pyobject_ptr.cpp:50:9), pybind11::return_value_policy>' requested here
    m.def(
      ^
/usr/local/google/home/rwgk/forked/pybind11/include/pybind11/cast.h:1077:3: note: candidate function [with T = _object *, $1 = 0]
T cast(object &&obj) {
  ^
/usr/local/google/home/rwgk/forked/pybind11/include/pybind11/cast.h:1149:1: note: candidate function [with T = _object *]
cast(object &&object) {
^
1 error generated.
```

* Reproducer for property setter with return type that is not wrapped.

* Use `py::class_<OptionsBase>()` to work around the return value conversion issue.

* WIP drop_return_value

* Remove struct drop_return_value

* Introduce `return_value_policy::return_none` for use by setters.

* Add `is_setter` to attr.h and use from `.def_property()`

* Merge the new test into test_methods_and_attributes

* Remove return_none return_value_policy again.

* Fix oversight (NOLINTNEXTLINE placement).

* Simplification (for the better) found while searching for a way to resolve GCC build failures.

Example of failure resolved by this change:

g++ (Ubuntu 9.4.0-1ubuntu1~20.04.1) 9.4.0

```
cd /build/tests && /usr/bin/c++ -DPYBIND11_TEST_EIGEN -Dpybind11_tests_EXPORTS -I/mounted_pybind11/include -isystem /usr/include/python3.8 -isystem /build/_deps/eigen-src -g -std=c++17 -fPIC -fvisibility=hidden -Wall -Wextra -Wconversion -Wcast-qual -Wdeprecated -Wundef -Wnon-virtual-dtor -MD -MT tests/CMakeFiles/pybind11_tests.dir/test_buffers.cpp.o -MF CMakeFiles/pybind11_tests.dir/test_buffers.cpp.o.d -o CMakeFiles/pybind11_tests.dir/test_buffers.cpp.o -c /mounted_pybind11/tests/test_buffers.cpp
In file included from /mounted_pybind11/include/pybind11/stl.h:12,
                 from /mounted_pybind11/tests/test_buffers.cpp:10:
/mounted_pybind11/include/pybind11/pybind11.h: In instantiation of ‘pybind11::class_<type_, options>& pybind11::class_<type_, options>::def_property(const char*, const Getter&, const Setter&, const Extra& ...) [with Getter = pybind11::cpp_function; Setter = std::nullptr_t; Extra = {pybind11::return_value_policy}; type_ = pybind11::buffer_info; options = {}]’:
/mounted_pybind11/include/pybind11/pybind11.h:1716:58:   required from ‘pybind11::class_<type_, options>& pybind11::class_<type_, options>::def_property_readonly(const char*, const pybind11::cpp_function&, const Extra& ...) [with Extra = {pybind11::return_value_policy}; type_ = pybind11::buffer_info; options = {}]’
/mounted_pybind11/include/pybind11/pybind11.h:1684:9:   required from ‘pybind11::class_<type_, options>& pybind11::class_<type_, options>::def_readonly(const char*, const D C::*, const Extra& ...) [with C = pybind11::buffer_info; D = long int; Extra = {}; type_ = pybind11::buffer_info; options = {}]’
/mounted_pybind11/tests/test_buffers.cpp:209:61:   required from here
/mounted_pybind11/include/pybind11/pybind11.h:1740:25: error: call of overloaded ‘cpp_function(std::nullptr_t&, pybind11::is_setter)’ is ambiguous
 1740 |             name, fget, cpp_function(method_adaptor<type>(fset), is_setter()), extra...);
      |                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/mounted_pybind11/include/pybind11/pybind11.h:101:5: note: candidate: ‘pybind11::cpp_function::cpp_function(Func&&, const Extra& ...) [with Func = std::nullptr_t&; Extra = {pybind11::is_setter}; <template-parameter-1-3> = void]’
  101 |     cpp_function(Func &&f, const Extra &...extra) {
      |     ^~~~~~~~~~~~
In file included from /mounted_pybind11/include/pybind11/stl.h:12,
                 from /mounted_pybind11/tests/test_buffers.cpp:10:
/mounted_pybind11/include/pybind11/pybind11.h:87:5: note: candidate: ‘pybind11::cpp_function::cpp_function(std::nullptr_t, const Extra& ...) [with Extra = {pybind11::is_setter}; std::nullptr_t = std::nullptr_t]’
   87 |     cpp_function(std::nullptr_t, const Extra &...) {}
      |     ^~~~~~~~~~~~
```

* Bug fix: obvious in hindsight. I thought the original version was incrementing the reference count for None, but no.

Discovered via many failing tests in the wild (10s of thousands).

It is very tricky to construct a meaningful unit test for this bug specifically. It's unlikely to come back, because 10s of thousands of tests will fail again.

`PyUnicode_DecodeLatin1` requires you to pass in the `error`
parameter. The code as it is in the docs didn't compile.

There is a reference leak in the example
code. `PyUnicode_DecodeLatin1` returns a new reference. Calling
`py::str(PyObject*)` calls `PyObject_Str`, which also returns a new
reference. That reference is managed by the `py::str`
constructor (which correctly steals the reference, using the
`stolen_t` constructor), but the original reference returned by
`PyUnicode_DecodeLatin1` is never decref'd: it never makes it into an
`object`, and it's never manually decremented.

This fixes both of those issues. The code compiles, and I viewed the
sphinx docs locally.

* set ci.yml minimal permissions

Signed-off-by: Joyce <[email protected]>

* set configure.yml minimal permissions

Signed-off-by: Joyce <[email protected]>

* set format.yml minimal permissions

Signed-off-by: Joyce <[email protected]>

* set pip.yml minimal permissions

Signed-off-by: Joyce <[email protected]>

* set upstream.yml minimal permissions

Signed-off-by: Joyce <[email protected]>

* set labeler.yml minimal permissions

Signed-off-by: Joyce <[email protected]>

* Update ci.yml to read all

Signed-off-by: Joyce <[email protected]>

* test labeler.yml

Signed-off-by: Joyce <[email protected]>

* restore the if at labeler.yml

Signed-off-by: Joyce <[email protected]>

---------

Signed-off-by: Joyce <[email protected]>

* Remove .dev1 from version number.

* [skip ci] Update changelog.rst

* [ci skip] Fix pre-commit: rst ``code`` is two backticks

* Apply fix suggested by @henryiii

* [ci skip] Set target date for the release to June 2, 2023

* [ci skip] Apply more fixes suggested by @henryiii (I missed those before).

* [ci skip] Revert "Remove .dev1 from version number."

This reverts commit afc80134cb1035be2913fd8153a16a864181c52c.

…(#4678)

* First version adding `__notes__` to `error_already_set::what()` output.

* Fix trivial oversight (missing adjustment in existing test).

* Minor enhancements of new code.

* Re-enable `cmake --target cpptest -j 2`

* Revert "Re-enable `cmake --target cpptest -j 2`"

This reverts commit 60816285e9e7b95b7d33a60805888b80b2bec641.

* Add general comment explaining why the `error_fetch_and_normalize` code is so unusual.

* Create SECURITY.md

* Update test_files.py to include SECURITY.md file

* Update MANIFEST.in to include SECURITY.md file

…ecializations. (#4674)

* Add `npy_format_descriptor<PyObject *>` to enable `py::array_t<PyObject *>` to/from-python conversions.

* resolve clang-tidy warning

* Use existing constructor instead of adding a static method. Thanks @Skylion007 for pointing out.

* Add `format_descriptor<PyObject *>`

Trivial addition, but still in search for a meaningful test.

* Add test_format_descriptor_format

* Ensure the Eigen `type_caster`s do not segfault when loading arrays with dtype=object

* Use `static_assert()` `!std::is_pointer<>` to replace runtime guards.

* Add comments to explain how to check for ref-count bugs. (NO code changes.)

* Make the "Pointer types ... are not supported" message Eigen-specific, as suggested by @lalaland. Move to new pybind11/eigen/common.h header.

* Change "format_descriptor_format" implementation as suggested by @lalaland. Additional tests meant to ensure consistency between py::format_descriptor<>, np.array, np.format_parser turn out to be useful only to highlight long-standing inconsistencies.

* resolve clang-tidy warning

* Account for np.float128, np.complex256 not being available on Windows, in a future-proof way.

* Fully address i|q|l ambiguity (hopefully).

* Remove the new `np.format_parser()`-based test, it's much more distracting than useful.

* Use bi.itemsize to disambiguate "l" or "L"

* Use `py::detail::compare_buffer_info<T>::compare()` to validate the `format_descriptor<T>::format()` strings.

* Add `buffer_info::compare<T>` to make `detail::compare_buffer_info<T>::compare` more visible & accessible.

* silence clang-tidy warning

* pytest-compatible access to np.float128, np.complex256

* Revert "pytest-compatible access to np.float128, np.complex256"

This reverts commit e9a289c50fc07199806d14ded644215ab6f03afa.

* Use `sizeof(long double) == sizeof(double)` instead of `std::is_same<>`

* Report skipped `long double` tests.

* Change the name of the new `buffer_info` member function to `item_type_is_equivalent_to`. Add comment defining "equivalent" by example.

* Change `item_type_is_equivalent_to<>()` from `static` function to member function, as suggested by @lalaland

* use Annotated for std::array docstring

* add tests

* fix test

* style: pre-commit fixes

* fix valarray annotation

* style: pre-commit fixes

* refix test

* add FixedSize

* style: pre-commit fixes

* Update test_stl.py

* style: pre-commit fixes

---------

Co-authored-by: Taiju Yamada <[email protected]>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

* chore(deps): update pre-commit hooks

updates:
- [github.com/charliermarsh/ruff-pre-commit: v0.0.263 → v0.0.270](astral-sh/ruff-pre-commit@v0.0.263...v0.0.270)
- [github.com/pre-commit/mirrors-mypy: v1.2.0 → v1.3.0](pre-commit/mirrors-mypy@v1.2.0...v1.3.0)
- [github.com/shellcheck-py/shellcheck-py: v0.9.0.2 → v0.9.0.5](shellcheck-py/shellcheck-py@v0.9.0.2...v0.9.0.5)
- [github.com/pre-commit/mirrors-clang-format: v16.0.2 → v16.0.4](pre-commit/mirrors-clang-format@v16.0.2...v16.0.4)

* Resolve new ruff error:

```
tests/test_pytypes.py:478:20: PLW0130 Duplicate value `3` in set
```

The reduction from `{3, 3}` to `{3}` never happened in pybind11 code, therefore this change is essentially a no-op for the purpose of unit-testing pybind11.

---------

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Bumps [deadsnakes/action](https://github.com/deadsnakes/action) from 3.0.0 to 3.0.1.
- [Release notes](https://github.com/deadsnakes/action/releases)
- [Commits](deadsnakes/action@v3.0.0...v3.0.1)

---
updated-dependencies:
- dependency-name: deadsnakes/action
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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* Uncomment `Interface test` sections (test_embed)

* fix: setuptools has been removed from default installs in 3.12

---------

Co-authored-by: Henry Schreiner <[email protected]>

* markdown-it-py dropped Python 3.7 support, but we are type checking for Python 3.7 from a newer version of Python. Keep using markdown-it-py<3 as long as we support Python 3.7.

* Shuffle order of pre-commit checks for better agility.

… which pip is called. (#4705)

* Systematically add PIP_BREAK_SYSTEM_PACKAGES to all .yml files from which pip is called.

* Try gcc:10-bullseye (because gcc:10 is broken: docker-library/gcc#95)

* bug fix (matrix did not work as hoped)

Signed-off-by: Henry Schreiner <[email protected]>

…. (#4717)

The gcc10 workaround was introduced with PR #4705.

* Trivial refactoring to make the capsule API more user friendly.

* Use new API in production code. Thanks @lalaland for pointing this out.

* chore: ruff moved to astral-sh

Committed via https://github.com/asottile/all-repos

* ci: bump CUDA version

* Remove `pypy-3.7` from ci.yml

* Update .github/workflows/ci.yml

---------

Co-authored-by: Henry Schreiner <[email protected]>

Bumps [scipy](https://github.com/scipy/scipy) from 1.8.0 to 1.10.0.
- [Release notes](https://github.com/scipy/scipy/releases)
- [Commits](scipy/scipy@v1.8.0...v1.10.0)

---
updated-dependencies:
- dependency-name: scipy
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
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updates:
- [github.com/pre-commit/mirrors-clang-format: v16.0.4 → v16.0.6](pre-commit/mirrors-clang-format@v16.0.4...v16.0.6)
- https://github.com/charliermarsh/ruff-pre-commit → https://github.com/astral-sh/ruff-pre-commit
- [github.com/astral-sh/ruff-pre-commit: v0.0.270 → v0.0.276](astral-sh/ruff-pre-commit@v0.0.270...v0.0.276)
- [github.com/pre-commit/mirrors-mypy: v1.3.0 → v1.4.1](pre-commit/mirrors-mypy@v1.3.0...v1.4.1)
- [github.com/asottile/blacken-docs: 1.13.0 → 1.14.0](adamchainz/blacken-docs@1.13.0...1.14.0)
- [github.com/codespell-project/codespell: v2.2.4 → v2.2.5](codespell-project/codespell@v2.2.4...v2.2.5)

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
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The previous sentence had an extra "a" before "several", which isn't right.

* Remove newlines from docstring signature

* Jean/dev (VOLTTRON#1)

Replace newlines in arg values with spaces

* style: pre-commit fixes

* Don't use std::find_if for C++ 11 compatibility

* Avoid implicit char to bool conversion

* Test default arguments for line breaks

* style: pre-commit fixes

* Separate Eigen tests

* style: pre-commit fixes

* Fix merge

* Try importing numpy

* Avoid unreferenced variable in catch block

* style: pre-commit fixes

* Update squash function

* Reduce try block

* Additional test cases

* style: pre-commit fixes

* Put statement inside braces

* Move string into function body

* Rename repr for better readability. Make constr explicit.

* Add multiline string default argument test case

* style: pre-commit fixes

* Add std namespace, do not modify string repr

* Test for all space chars, test str repr not modified

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

…_VER (#2898) (#4779)

… See comments there. (#4819)

* fix: Enum __str__ function name

* tests: Test enum.__str__.__doc__

* fix: Render `py::function` as `Callable`

* style: pre-commit fixes

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

* Change variable name `it` to `curr_overl` to improve readability, add `assert()` in the only place where `curr_overl` could become `nullptr`.

* Move the `assert()` to where Coverty generates a false positive.

* variable name as suggested by @henryiii

* chore(deps): update pre-commit hooks

updates:
- [github.com/astral-sh/ruff-pre-commit: v0.0.281 → v0.0.287](astral-sh/ruff-pre-commit@v0.0.281...v0.0.287)
- [github.com/pre-commit/mirrors-mypy: v1.4.1 → v1.5.1](pre-commit/mirrors-mypy@v1.4.1...v1.5.1)
- [github.com/asottile/blacken-docs: 1.15.0 → 1.16.0](adamchainz/blacken-docs@1.15.0...1.16.0)
- [github.com/Lucas-C/pre-commit-hooks: v1.5.1 → v1.5.4](Lucas-C/pre-commit-hooks@v1.5.1...v1.5.4)
- [github.com/PyCQA/pylint: v3.0.0a6 → v3.0.0a7](pylint-dev/pylint@v3.0.0a6...v3.0.0a7)

* style: pre-commit fixes

* Update pyproject.toml

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
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* chore(deps): bump actions/checkout from 1 to 4

Bumps [actions/checkout](https://github.com/actions/checkout) from 1 to 4.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v1...v4)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

* Update .github/workflows/ci.yml

* actions/checkout@v1 for centos:7

* Fix oversight: centos:7 actually works with actions/checkout@v3

---------

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
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* feature: Support move-only iterators in `py::make_*iterator`

* fix: Missing static assertion message

* fixup: Missing `explicit` in single argument constructors

* fix: Simplify tests: make existing iterator move-only

* fix: Missing `noexcept`

* fix: Add capitalize render name of `py::buffer` and `py::sequence`

* fix: Render `py::handle` same way as `py::object`

* tests: Fix tests `handle` -> `object`

* tests: Test capitaliation of `py::sequence` and `py::buffer`

* style: pre-commit fixes

* fix: Render `py::object` as `Any`

* Revert "fix: Render `py::object` as `Any`"

This reverts commit 7861dcfabb78ac210b4c67c35a0d47fb67525a96.

---------

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* Bug fix: `result[0]` called if `result.empty()`

* Add unit test that fails without the fix.

…806)

* cmake: split extension

Into suffix and debug postfix. Pybind11 is currently treating both as
suffix, which is problematic when something else defines the
DEBUG_POSTFIX because they will be concatenated.

pybind11_extension sets SUFFIX to _d.something and if DEBUG_POSTFIX is
set to _d.

    _d + _d.something = _d_d.something

The issue has been reported at:

pybind/pybind11#4699

* style: pre-commit fixes

* fix(cmake): support postfix for old FindPythonInterp mode too

Signed-off-by: Henry Schreiner <[email protected]>

---------

Signed-off-by: Henry Schreiner <[email protected]>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Henry Schreiner <[email protected]>

This change is fixing a Coverity AUTO_CAUSES_COPY issues.

Fixes oversights in PR #4570.

* MAINT: Include numpy._core imports

* style: pre-commit fixes

* Apply review comments

* style: pre-commit fixes

* Add no-inline attribute

* Select submodule name based on numpy version

* style: pre-commit fixes

* Update pre-commit check

* Add error_already_set and simplify if statement

* Update .pre-commit-config.yaml

Co-authored-by: Ralf W. Grosse-Kunstleve <[email protected]>

---------

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Co-authored-by: Ralf W. Grosse-Kunstleve <[email protected]>

* chore(deps): update pre-commit hooks

updates:
- [github.com/psf/black-pre-commit-mirror: 23.7.0 → 23.9.1](psf/black-pre-commit-mirror@23.7.0...23.9.1)
- [github.com/astral-sh/ruff-pre-commit: v0.0.287 → v0.0.292](astral-sh/ruff-pre-commit@v0.0.287...v0.0.292)
- [github.com/codespell-project/codespell: v2.2.5 → v2.2.6](codespell-project/codespell@v2.2.5...v2.2.6)
- [github.com/shellcheck-py/shellcheck-py: v0.9.0.5 → v0.9.0.6](shellcheck-py/shellcheck-py@v0.9.0.5...v0.9.0.6)
- [github.com/PyCQA/pylint: v3.0.0a7 → v3.0.0](pylint-dev/pylint@v3.0.0a7...v3.0.0)

* Update .pre-commit-config.yaml

* style: pre-commit fixes

* Update .pre-commit-config.yaml

---------

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Bumps [seanmiddleditch/gha-setup-ninja](https://github.com/seanmiddleditch/gha-setup-ninja) from 3 to 4.
- [Release notes](https://github.com/seanmiddleditch/gha-setup-ninja/releases)
- [Commits](seanmiddleditch/gha-setup-ninja@v3...v4)

---
updated-dependencies:
- dependency-name: seanmiddleditch/gha-setup-ninja
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

….h) (#4877)

* LazyInitializeAtLeastOnceDestroyNever v1

* Go back to using `union` as originally suggested by jbms@. The trick (also suggested by jbms@) is to add empty ctor + dtor.

* Revert "Go back to using `union` as originally suggested by jbms@. The trick (also suggested by jbms@) is to add empty ctor + dtor."

This reverts commit e7b8c4f0fcd72191e88d1c17abf5da08fe3a9c6f.

* Remove `#include <stdalign.h>`

* `include\pybind11/numpy.h(24,10): fatal error C1083: Cannot open include file: 'stdalign.h': No such file or directory`

* @tkoeppe wrote: this is a C interop header (and we're not writing C)

* Suppress gcc 4.8.5 (CentOS 7) warning.

```
include/pybind11/eigen/../numpy.h:63:53: error: dereferencing type-punned pointer will break strict-aliasing rules [-Werror=strict-aliasing]
         return *reinterpret_cast<T *>(value_storage_);
                                                     ^
```

* Replace comments:

Document PRECONDITION.

Adopt comment suggested by @tkoeppe: pybind/pybind11#4877 (comment)

* Adopt suggestion by @tkoeppe:

* pybind/pybind11#4877 (comment)

* https://godbolt.org/z/Wa79nKz6e

* Add `PYBIND11_CONSTINIT`, but it does not work for the current use cases:

```
g++ -o pybind11/tests/test_numpy_array.os -c -std=c++20 -fPIC -fvisibility=hidden -O0 -g -Wall -Wextra -Wconversion -Wcast-qual -Wdeprecated -Wundef -Wnon-virtual-dtor -Wunused-result -Werror -isystem /usr/include/python3.11 -isystem /usr/include/eigen3 -DPYBIND11_STRICT_ASSERTS_CLASS_HOLDER_VS_TYPE_CASTER_MIX -DPYBIND11_ENABLE_TYPE_CASTER_ODR_GUARD_IF_AVAILABLE -DPYBIND11_TEST_BOOST -Ipybind11/include -I/usr/local/google/home/rwgk/forked/pybind11/include -I/usr/local/google/home/rwgk/clone/pybind11/include /usr/local/google/home/rwgk/forked/pybind11/tests/test_numpy_array.cpp
```

```
In file included from /usr/local/google/home/rwgk/forked/pybind11/tests/test_numpy_array.cpp:10:
/usr/local/google/home/rwgk/forked/pybind11/include/pybind11/numpy.h: In static member function ‘static pybind11::detail::npy_api& pybind11::detail::npy_api::get()’:
/usr/local/google/home/rwgk/forked/pybind11/include/pybind11/numpy.h:258:82: error: ‘constinit’ variable ‘api_init’ does not have a constant initializer
  258 |         PYBIND11_CONSTINIT static LazyInitializeAtLeastOnceDestroyNever<npy_api> api_init;
      |                                                                                  ^~~~~~~~
```

```
In file included from /usr/local/google/home/rwgk/forked/pybind11/tests/test_numpy_array.cpp:10:
/usr/local/google/home/rwgk/forked/pybind11/include/pybind11/numpy.h: In static member function ‘static pybind11::object& pybind11::dtype::_dtype_from_pep3118()’:
/usr/local/google/home/rwgk/forked/pybind11/include/pybind11/numpy.h:697:13: error: ‘constinit’ variable ‘imported_obj’ does not have a constant initializer
  697 |             imported_obj;
      |             ^~~~~~~~~~~~
```

* Revert "Add `PYBIND11_CONSTINIT`, but it does not work for the current use cases:"

This reverts commit f07b28bda9f91fb723aa898a21c81b6dd6857072.

* Reapply "Add `PYBIND11_CONSTINIT`, but it does not work for the current use cases:"

This reverts commit 36be645758aa82b576d24003808386bec6e55bf9.

* Add Default Member Initializer on `value_storage_` as suggested by @tkoeppe:

pybind/pybind11#4877 (comment)

This fixes the errors reported under commit f07b28bda9f91fb723aa898a21c81b6dd6857072.

* Fix copy-paste-missed-a-change mishap in commit 88cec1152ab5576db19bab95c484672f06f5989a.

* Semi-paranoid placement new (based on pybind/pybind11#4877 (comment)).

* Move PYBIND11_CONSTINIT to detail/common.h

* Move code to the right places, rename new class and some variables.

* Fix oversight: update tests/extra_python_package/test_files.py

* Get the name right first.

* Use `std::call_once`, `std::atomic`, following a pattern developed by @tkoeppe

* Make the API more self-documenting (and possibly more easily reusable).

* google-clang-tidy IWYU fixes

* Rewrite comment as suggested by @tkoeppe

* Update test_exceptions.cpp and exceptions.rst

* Fix oversight in previous commit: add `PYBIND11_CONSTINIT`

* Make `get_stored()` non-const for simplicity.

As suggested by @tkoeppe: not seeing any reasonable use in which `get_stored` has to be const.

* Add comment regarding `KeyboardInterrupt` behavior, based heavily on information provided by @jbms.

* Add `assert(PyGILState_Check())` in `gil_scoped_release` ctor (simple & non-simple implementation) as suggested by @EthanSteinberg.

* Fix oversight in previous commit (missing include cassert).

* Remove use of std::atomic, leaving comments with rationale, why it is not needed.

* Rewrite comment re `std:optional` based on deeper reflection (aka 2nd thoughts).

* Additional comment with the conclusion of a discussion under PR #4877.

* pybind/pybind11#4877 (comment)

* Small comment changes suggested by @tkoeppe.

… (#4880)

* Update pytest (which removes their dependency on py)

The py library through 1.11.0 for Python allows remote attackers to conduct a ReDoS (Regular expression Denial of Service) attack via a Subversion repository with crafted info data, because the InfoSvnCommand argument is mishandled.

The particular codepath in question is the regular expression at py._path.svnurl.InfoSvnCommand.lspattern and is only relevant when dealing with subversion (svn) projects. Notably the codepath is not used in the popular pytest project. The developers of the pytest package have released version 7.2.0 which removes their dependency on py. Users of pytest seeing alerts relating to this advisory may update to version 7.2.0 of pytest to resolve this issue. See pytest-dev/py#287 (comment) for additional context.

* Added conditions so that we keep using 7.0.0 on python 3.6

pybind11::cast_error:
     return_value_policy = copy, but the object is non-copyable!

May be the same/related issue as described here:
     pybind#1241

Adapted from:
338d615