first commit

third_party/pybind11/.github/CODEOWNERS

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+*.cmake @henryiii
+CMakeLists.txt @henryiii
+*.yml @henryiii
+*.yaml @henryiii
+/tools/ @henryiii
+/pybind11/ @henryiii
+noxfile.py @henryiii
+.clang-format @henryiii
+.clang-tidy @henryiii

third_party/pybind11/.github/CONTRIBUTING.md

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+Thank you for your interest in this project! Please refer to the following
+sections on how to contribute code and bug reports.
+
+### Reporting bugs
+
+Before submitting a question or bug report, please take a moment of your time
+and ensure that your issue isn't already discussed in the project documentation
+provided at [pybind11.readthedocs.org][] or in the [issue tracker][]. You can
+also check [gitter][] to see if it came up before.
+
+Assuming that you have identified a previously unknown problem or an important
+question, it's essential that you submit a self-contained and minimal piece of
+code that reproduces the problem. In other words: no external dependencies,
+isolate the function(s) that cause breakage, submit matched and complete C++
+and Python snippets that can be easily compiled and run in isolation; or
+ideally make a small PR with a failing test case that can be used as a starting
+point.
+
+## Pull requests
+
+Contributions are submitted, reviewed, and accepted using GitHub pull requests.
+Please refer to [this article][using pull requests] for details and adhere to
+the following rules to make the process as smooth as possible:
+
+* Make a new branch for every feature you're working on.
+* Make small and clean pull requests that are easy to review but make sure they
+  do add value by themselves.
+* Add tests for any new functionality and run the test suite (`cmake --build
+  build --target pytest`) to ensure that no existing features break.
+* Please run [`pre-commit`][pre-commit] to check your code matches the
+  project style. (Note that `gawk` is required.) Use `pre-commit run
+  --all-files` before committing (or use installed-mode, check pre-commit docs)
+  to verify your code passes before pushing to save time.
+* This project has a strong focus on providing general solutions using a
+  minimal amount of code, thus small pull requests are greatly preferred.
+
+### Licensing of contributions
+
+pybind11 is provided under a BSD-style license that can be found in the
+``LICENSE`` file. By using, distributing, or contributing to this project, you
+agree to the terms and conditions of this license.
+
+You are under no obligation whatsoever to provide any bug fixes, patches, or
+upgrades to the features, functionality or performance of the source code
+("Enhancements") to anyone; however, if you choose to make your Enhancements
+available either publicly, or directly to the author of this software, without
+imposing a separate written license agreement for such Enhancements, then you
+hereby grant the following license: a non-exclusive, royalty-free perpetual
+license to install, use, modify, prepare derivative works, incorporate into
+other computer software, distribute, and sublicense such enhancements or
+derivative works thereof, in binary and source code form.
+
+
+## Development of pybind11
+
+### Quick setup
+
+To setup a quick development environment, use [`nox`](https://nox.thea.codes).
+This will allow you to do some common tasks with minimal setup effort, but will
+take more time to run and be less flexible than a full development environment.
+If you use [`pipx run nox`](https://pipx.pypa.io), you don't even need to
+install `nox`. Examples:
+
+```bash
+# List all available sessions
+nox -l
+
+# Run linters
+nox -s lint
+
+# Run tests on Python 3.9
+nox -s tests-3.9
+
+# Build and preview docs
+nox -s docs -- serve
+
+# Build SDists and wheels
+nox -s build
+```
+
+### Full setup
+
+To setup an ideal development environment, run the following commands on a
+system with CMake 3.14+:
+
+```bash
+python3 -m venv venv
+source venv/bin/activate
+pip install -r tests/requirements.txt
+cmake -S . -B build -DDOWNLOAD_CATCH=ON -DDOWNLOAD_EIGEN=ON
+cmake --build build -j4
+```
+
+Tips:
+
+* You can use `virtualenv` (faster, from PyPI) instead of `venv`.
+* You can select any name for your environment folder; if it contains "env" it
+  will be ignored by git.
+* If you don't have CMake 3.14+, just add "cmake" to the pip install command.
+* You can use `-DPYBIND11_FINDPYTHON=ON` to use FindPython on CMake 3.12+
+* In classic mode, you may need to set `-DPYTHON_EXECUTABLE=/path/to/python`.
+  FindPython uses `-DPython_ROOT_DIR=/path/to` or
+  `-DPython_EXECUTABLE=/path/to/python`.
+
+### Configuration options
+
+In CMake, configuration options are given with "-D". Options are stored in the
+build directory, in the `CMakeCache.txt` file, so they are remembered for each
+build directory. Two selections are special - the generator, given with `-G`,
+and the compiler, which is selected based on environment variables `CXX` and
+similar, or `-DCMAKE_CXX_COMPILER=`. Unlike the others, these cannot be changed
+after the initial run.
+
+The valid options are:
+
+* `-DCMAKE_BUILD_TYPE`: Release, Debug, MinSizeRel, RelWithDebInfo
+* `-DPYBIND11_FINDPYTHON=ON`: Use CMake 3.12+'s FindPython instead of the
+  classic, deprecated, custom FindPythonLibs
+* `-DPYBIND11_NOPYTHON=ON`: Disable all Python searching (disables tests)
+* `-DBUILD_TESTING=ON`: Enable the tests
+* `-DDOWNLOAD_CATCH=ON`: Download catch to build the C++ tests
+* `-DDOWNLOAD_EIGEN=ON`: Download Eigen for the NumPy tests
+* `-DPYBIND11_INSTALL=ON/OFF`: Enable the install target (on by default for the
+  master project)
+* `-DUSE_PYTHON_INSTALL_DIR=ON`: Try to install into the python dir
+
+
+<details><summary>A few standard CMake tricks: (click to expand)</summary><p>
+
+* Use `cmake --build build -v` to see the commands used to build the files.
+* Use `cmake build -LH` to list the CMake options with help.
+* Use `ccmake` if available to see a curses (terminal) gui, or `cmake-gui` for
+  a completely graphical interface (not present in the PyPI package).
+* Use `cmake --build build -j12` to build with 12 cores (for example).
+* Use `-G` and the name of a generator to use something different. `cmake
+  --help` lists the generators available.
+      - On Unix, setting `CMAKE_GENERATER=Ninja` in your environment will give
+        you automatic mulithreading on all your CMake projects!
+* Open the `CMakeLists.txt` with QtCreator to generate for that IDE.
+* You can use `-DCMAKE_EXPORT_COMPILE_COMMANDS=ON` to generate the `.json` file
+  that some tools expect.
+
+</p></details>
+
+
+To run the tests, you can "build" the check target:
+
+```bash
+cmake --build build --target check
+```
+
+`--target` can be spelled `-t` in CMake 3.15+. You can also run individual
+tests with these targets:
+
+* `pytest`: Python tests only, using the
+[pytest](https://docs.pytest.org/en/stable/) framework
+* `cpptest`: C++ tests only
+* `test_cmake_build`: Install / subdirectory tests
+
+If you want to build just a subset of tests, use
+`-DPYBIND11_TEST_OVERRIDE="test_callbacks;test_pickling"`. If this is
+empty, all tests will be built. Tests are specified without an extension if they need both a .py and
+.cpp file.
+
+You may also pass flags to the `pytest` target by editing `tests/pytest.ini` or
+by using the `PYTEST_ADDOPTS` environment variable
+(see [`pytest` docs](https://docs.pytest.org/en/2.7.3/customize.html#adding-default-options)). As an example:
+
+```bash
+env PYTEST_ADDOPTS="--capture=no --exitfirst" \
+    cmake --build build --target pytest
+# Or using abbreviated flags
+env PYTEST_ADDOPTS="-s -x" cmake --build build --target pytest
+```
+
+### Formatting
+
+All formatting is handled by pre-commit.
+
+Install with brew (macOS) or pip (any OS):
+
+```bash
+# Any OS
+python3 -m pip install pre-commit
+
+# OR macOS with homebrew:
+brew install pre-commit
+```
+
+Then, you can run it on the items you've added to your staging area, or all
+files:
+
+```bash
+pre-commit run
+# OR
+pre-commit run --all-files
+```
+
+And, if you want to always use it, you can install it as a git hook (hence the
+name, pre-commit):
+
+```bash
+pre-commit install
+```
+
+### Clang-Format
+
+As of v2.6.2, pybind11 ships with a [`clang-format`][clang-format]
+configuration file at the top level of the repo (the filename is
+`.clang-format`). Currently, formatting is NOT applied automatically, but
+manually using `clang-format` for newly developed files is highly encouraged.
+To check if a file needs formatting:
+
+```bash
+clang-format -style=file --dry-run some.cpp
+```
+
+The output will show things to be fixed, if any. To actually format the file:
+
+```bash
+clang-format -style=file -i some.cpp
+```
+
+Note that the `-style-file` option searches the parent directories for the
+`.clang-format` file, i.e. the commands above can be run in any subdirectory
+of the pybind11 repo.
+
+### Clang-Tidy
+
+[`clang-tidy`][clang-tidy] performs deeper static code analyses and is
+more complex to run, compared to `clang-format`, but support for `clang-tidy`
+is built into the pybind11 CMake configuration. To run `clang-tidy`, the
+following recipe should work. Run the `docker` command from the top-level
+directory inside your pybind11 git clone. Files will be modified in place,
+so you can use git to monitor the changes.
+
+```bash
+docker run --rm -v $PWD:/mounted_pybind11 -it silkeh/clang:12
+apt-get update && apt-get install -y python3-dev python3-pytest
+cmake -S /mounted_pybind11/ -B build -DCMAKE_CXX_CLANG_TIDY="$(which clang-tidy);-fix" -DDOWNLOAD_EIGEN=ON -DDOWNLOAD_CATCH=ON -DCMAKE_CXX_STANDARD=17
+cmake --build build -j 2 -- --keep-going
+```
+
+### Include what you use
+
+To run include what you use, install (`brew install include-what-you-use` on
+macOS), then run:
+
+```bash
+cmake -S . -B build-iwyu -DCMAKE_CXX_INCLUDE_WHAT_YOU_USE=$(which include-what-you-use)
+cmake --build build
+```
+
+The report is sent to stderr; you can pipe it into a file if you wish.
+
+### Build recipes
+
+This builds with the Intel compiler (assuming it is in your path, along with a
+recent CMake and Python):
+
+```bash
+python3 -m venv venv
+. venv/bin/activate
+pip install pytest
+cmake -S . -B build-intel -DCMAKE_CXX_COMPILER=$(which icpc) -DDOWNLOAD_CATCH=ON -DDOWNLOAD_EIGEN=ON -DPYBIND11_WERROR=ON
+```
+
+This will test the PGI compilers:
+
+```bash
+docker run --rm -it -v $PWD:/pybind11 nvcr.io/hpc/pgi-compilers:ce
+apt-get update && apt-get install -y python3-dev python3-pip python3-pytest
+wget -qO- "https://cmake.org/files/v3.18/cmake-3.18.2-Linux-x86_64.tar.gz" | tar --strip-components=1 -xz -C /usr/local
+cmake -S pybind11/ -B build
+cmake --build build
+```
+
+### Explanation of the SDist/wheel building design
+
+> These details below are _only_ for packaging the Python sources from git. The
+> SDists and wheels created do not have any extra requirements at all and are
+> completely normal.
+
+The main objective of the packaging system is to create SDists (Python's source
+distribution packages) and wheels (Python's binary distribution packages) that
+include everything that is needed to work with pybind11, and which can be
+installed without any additional dependencies. This is more complex than it
+appears: in order to support CMake as a first class language even when using
+the PyPI package, they must include the _generated_ CMake files (so as not to
+require CMake when installing the `pybind11` package itself). They should also
+provide the option to install to the "standard" location
+(`<ENVROOT>/include/pybind11` and `<ENVROOT>/share/cmake/pybind11`) so they are
+easy to find with CMake, but this can cause problems if you are not an
+environment or using ``pyproject.toml`` requirements. This was solved by having
+two packages; the "nice" pybind11 package that stores the includes and CMake
+files inside the package, that you get access to via functions in the package,
+and a `pybind11-global` package that can be included via `pybind11[global]` if
+you want the more invasive but discoverable file locations.
+
+If you want to install or package the GitHub source, it is best to have Pip 10
+or newer on Windows, macOS, or Linux (manylinux1 compatible, includes most
+distributions).  You can then build the SDists, or run any procedure that makes
+SDists internally, like making wheels or installing.
+
+
+```bash
+# Editable development install example
+python3 -m pip install -e .
+```
+
+Since Pip itself does not have an `sdist` command (it does have `wheel` and
+`install`), you may want to use the upcoming `build` package:
+
+```bash
+python3 -m pip install build
+
+# Normal package
+python3 -m build -s .
+
+# Global extra
+PYBIND11_GLOBAL_SDIST=1 python3 -m build -s .
+```
+
+If you want to use the classic "direct" usage of `python setup.py`, you will
+need CMake 3.15+ and either `make` or `ninja` preinstalled (possibly via `pip
+install cmake ninja`), since directly running Python on `setup.py` cannot pick
+up and install `pyproject.toml` requirements. As long as you have those two
+things, though, everything works the way you would expect:
+
+```bash
+# Normal package
+python3 setup.py sdist
+
+# Global extra
+PYBIND11_GLOBAL_SDIST=1 python3 setup.py sdist
+```
+
+A detailed explanation of the build procedure design for developers wanting to
+work on or maintain the packaging system is as follows:
+
+#### 1. Building from the source directory
+
+When you invoke any `setup.py` command from the source directory, including
+`pip wheel .` and `pip install .`, you will activate a full source build. This
+is made of the following steps:
+
+1. If the tool is PEP 518 compliant, like Pip 10+, it will create a temporary
+   virtual environment and install the build requirements (mostly CMake) into
+   it. (if you are not on Windows, macOS, or a manylinux compliant system, you
+   can disable this with `--no-build-isolation` as long as you have CMake 3.15+
+   installed)
+2. The environment variable `PYBIND11_GLOBAL_SDIST` is checked - if it is set
+   and truthy, this will be make the accessory `pybind11-global` package,
+   instead of the normal `pybind11` package. This package is used for
+   installing the files directly to your environment root directory, using
+   `pybind11[global]`.
+2. `setup.py` reads the version from `pybind11/_version.py` and verifies it
+   matches `includes/pybind11/detail/common.h`.
+3. CMake is run with `-DCMAKE_INSTALL_PREIFX=pybind11`. Since the CMake install
+   procedure uses only relative paths and is identical on all platforms, these
+   files are valid as long as they stay in the correct relative position to the
+   includes. `pybind11/share/cmake/pybind11` has the CMake files, and
+   `pybind11/include` has the includes. The build directory is discarded.
+4. Simpler files are placed in the SDist: `tools/setup_*.py.in`,
+   `tools/pyproject.toml` (`main` or `global`)
+5. The package is created by running the setup function in the
+   `tools/setup_*.py`.  `setup_main.py` fills in Python packages, and
+   `setup_global.py` fills in only the data/header slots.
+6. A context manager cleans up the temporary CMake install directory (even if
+   an error is thrown).
+
+### 2. Building from SDist
+
+Since the SDist has the rendered template files in `tools` along with the
+includes and CMake files in the correct locations, the builds are completely
+trivial and simple. No extra requirements are required. You can even use Pip 9
+if you really want to.
+
+
+[pre-commit]: https://pre-commit.com
+[clang-format]: https://clang.llvm.org/docs/ClangFormat.html
+[clang-tidy]: https://clang.llvm.org/extra/clang-tidy/
+[pybind11.readthedocs.org]: http://pybind11.readthedocs.org/en/latest
+[issue tracker]: https://github.com/pybind/pybind11/issues
+[gitter]: https://gitter.im/pybind/Lobby
+[using pull requests]: https://help.github.com/articles/using-pull-requests

third_party/pybind11/.github/ISSUE_TEMPLATE/bug-report.yml

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+name: Bug Report
+description: File an issue about a bug
+title: "[BUG]: "
+labels: [triage]
+body:
+  - type: markdown
+    attributes:
+      value: |
+        Maintainers will only make a best effort to triage PRs. Please do your best to make the issue as easy to act on as possible, and only open if clearly a problem with pybind11 (ask first if unsure).
+  - type: checkboxes
+    id: steps
+    attributes:
+      label: Required prerequisites
+      description: Make sure you've completed the following steps before submitting your issue -- thank you!
+      options:
+        - label: Make sure you've read the [documentation](https://pybind11.readthedocs.io). Your issue may be addressed there.
+          required: true
+        - label: Search the [issue tracker](https://github.com/pybind/pybind11/issues) and [Discussions](https:/pybind/pybind11/discussions) to verify that this hasn't already been reported. +1 or comment there if it has.
+          required: true
+        - label: Consider asking first in the [Gitter chat room](https://gitter.im/pybind/Lobby) or in a [Discussion](https:/pybind/pybind11/discussions/new).
+          required: false
+
+  - type: textarea
+    id: description
+    attributes:
+      label: Problem description
+      placeholder: >-
+        Provide a short description, state the expected behavior and what
+        actually happens. Include relevant information like what version of
+        pybind11 you are using, what system you are on, and any useful commands
+        / output.
+    validations:
+      required: true
+
+  - type: textarea
+    id: code
+    attributes:
+      label: Reproducible example code
+      placeholder: >-
+        The code should be minimal, have no external dependencies, isolate the
+        function(s) that cause breakage. Submit matched and complete C++ and
+        Python snippets that can be easily compiled and run to diagnose the
+        issue. If possible, make a PR with a new, failing test to give us a
+        starting point to work on!
+      render: text

third_party/pybind11/.github/ISSUE_TEMPLATE/config.yml

@@ -0,0 +1,8 @@
+blank_issues_enabled: false
+contact_links:
+  - name: Ask a question
+    url: https://github.com/pybind/pybind11/discussions/new
+    about: Please ask and answer questions here, or propose new ideas.
+  - name: Gitter room
+    url: https://gitter.im/pybind/Lobby
+    about: A room for discussing pybind11 with an active community

third_party/pybind11/.github/dependabot.yml

@@ -0,0 +1,11 @@
+version: 2
+updates:
+  # Maintain dependencies for GitHub Actions
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "daily"
+    ignore:
+      # Official actions have moving tags like v1
+      - dependency-name: "actions/*"
+        update-types: ["version-update:semver-minor", "version-update:semver-patch"]

third_party/pybind11/.github/labeler.yml

@@ -0,0 +1,8 @@
+docs:
+- any:
+  - 'docs/**/*.rst'
+  - '!docs/changelog.rst'
+  - '!docs/upgrade.rst'
+
+ci:
+- '.github/workflows/*.yml'

third_party/pybind11/.github/labeler_merged.yml

@@ -0,0 +1,3 @@
+needs changelog:
+- all:
+  - '!docs/changelog.rst'

third_party/pybind11/.github/matchers/pylint.json

@@ -0,0 +1,32 @@
+{
+  "problemMatcher": [
+    {
+      "severity": "warning",
+      "pattern": [
+        {
+          "regexp": "^([^:]+):(\\d+):(\\d+): ([A-DF-Z]\\d+): \\033\\[[\\d;]+m([^\\033]+).*$",
+          "file": 1,
+          "line": 2,
+          "column": 3,
+          "code": 4,
+          "message": 5
+        }
+      ],
+      "owner": "pylint-warning"
+    },
+    {
+      "severity": "error",
+      "pattern": [
+        {
+          "regexp": "^([^:]+):(\\d+):(\\d+): (E\\d+): \\033\\[[\\d;]+m([^\\033]+).*$",
+          "file": 1,
+          "line": 2,
+          "column": 3,
+          "code": 4,
+          "message": 5
+        }
+      ],
+      "owner": "pylint-error"
+    }
+  ]
+}

third_party/pybind11/.github/pull_request_template.md

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+<!--
+Title (above): please place [branch_name] at the beginning if you are targeting a branch other than master. *Do not target stable*.
+It is recommended to use conventional commit format, see conventionalcommits.org, but not required.
+-->
+## Description
+
+<!-- Include relevant issues or PRs here, describe what changed and why -->
+
+
+## Suggested changelog entry:
+
+<!-- Fill in the below block with the expected RestructuredText entry. Delete if no entry needed;
+     but do not delete header or rst block if an entry is needed! Will be collected via a script. -->
+
+```rst
+
+```
+
+<!-- If the upgrade guide needs updating, note that here too -->

third_party/pybind11/.github/workflows/ci.yml

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+name: CI
+
+on:
+  workflow_dispatch:
+  pull_request:
+  push:
+    branches:
+      - master
+      - stable
+      - v*
+
+concurrency:
+  group: test-${{ github.ref }}
+  cancel-in-progress: true
+
+env:
+  PIP_ONLY_BINARY: numpy
+  FORCE_COLOR: 3
+  PYTEST_TIMEOUT: 300
+
+jobs:
+  # This is the "main" test suite, which tests a large number of different
+  # versions of default compilers and Python versions in GitHub Actions.
+  standard:
+    strategy:
+      fail-fast: false
+      matrix:
+        runs-on: [ubuntu-latest, windows-2022, macos-latest]
+        python:
+        - '3.6'
+        - '3.9'
+        - '3.10'
+        - 'pypy-3.7'
+        - 'pypy-3.8'
+        - 'pypy-3.9'
+
+        # Items in here will either be added to the build matrix (if not
+        # present), or add new keys to an existing matrix element if all the
+        # existing keys match.
+        #
+        # We support an optional key: args, for cmake args
+        include:
+          # Just add a key
+          - runs-on: ubuntu-latest
+            python: '3.6'
+            args: >
+              -DPYBIND11_FINDPYTHON=ON
+              -DCMAKE_CXX_FLAGS="-D_=1"
+          - runs-on: ubuntu-latest
+            python: 'pypy-3.8'
+            args: >
+              -DPYBIND11_FINDPYTHON=ON
+          - runs-on: windows-2019
+            python: '3.6'
+            args: >
+              -DPYBIND11_FINDPYTHON=ON
+          # Inject a couple Windows 2019 runs
+          - runs-on: windows-2019
+            python: '3.9'
+
+    name: "🐍 ${{ matrix.python }} • ${{ matrix.runs-on }} • x64 ${{ matrix.args }}"
+    runs-on: ${{ matrix.runs-on }}
+
+    steps:
+    - uses: actions/checkout@v3
+
+    - name: Setup Python ${{ matrix.python }}
+      uses: actions/setup-python@v3
+      with:
+        python-version: ${{ matrix.python }}
+
+    - name: Setup Boost (Linux)
+      # Can't use boost + define _
+      if: runner.os == 'Linux' && matrix.python != '3.6'
+      run: sudo apt-get install libboost-dev
+
+    - name: Setup Boost (macOS)
+      if: runner.os == 'macOS'
+      run: brew install boost
+
+    - name: Update CMake
+      uses: jwlawson/actions-setup-cmake@v1.12
+
+    - name: Cache wheels
+      if: runner.os == 'macOS'
+      uses: actions/cache@v3
+      with:
+        # This path is specific to macOS - we really only need it for PyPy NumPy wheels
+        # See https://github.com/actions/cache/blob/master/examples.md#python---pip
+        # for ways to do this more generally
+        path: ~/Library/Caches/pip
+        # Look to see if there is a cache hit for the corresponding requirements file
+        key: ${{ runner.os }}-pip-${{ matrix.python }}-x64-${{ hashFiles('tests/requirements.txt') }}
+
+    - name: Prepare env
+      run: |
+        python -m pip install -r tests/requirements.txt
+
+    - name: Setup annotations on Linux
+      if: runner.os == 'Linux'
+      run: python -m pip install pytest-github-actions-annotate-failures
+
+    # First build - C++11 mode and inplace
+    - name: Configure C++11 ${{ matrix.args }}
+      run: >
+        cmake -S . -B .
+        -DPYBIND11_WERROR=ON
+        -DDOWNLOAD_CATCH=ON
+        -DDOWNLOAD_EIGEN=ON
+        -DCMAKE_CXX_STANDARD=11
+        ${{ matrix.args }}
+
+    - name: Build C++11
+      run: cmake --build . -j 2
+
+    - name: Python tests C++11
+      run: cmake --build . --target pytest -j 2
+
+    - name: C++11 tests
+      # TODO: Figure out how to load the DLL on Python 3.8+
+      if: "!(runner.os == 'Windows' && (matrix.python == 3.8 || matrix.python == 3.9 || matrix.python == '3.10' || matrix.python == '3.11-dev' || matrix.python == 'pypy-3.8'))"
+      run: cmake --build .  --target cpptest -j 2
+
+    - name: Interface test C++11
+      run: cmake --build . --target test_cmake_build
+
+    - name: Clean directory
+      run: git clean -fdx
+
+    # Second build - C++17 mode and in a build directory
+    - name: Configure C++17
+      run: >
+        cmake -S . -B build2
+        -DPYBIND11_WERROR=ON
+        -DDOWNLOAD_CATCH=ON
+        -DDOWNLOAD_EIGEN=ON
+        -DCMAKE_CXX_STANDARD=17
+        ${{ matrix.args }}
+
+    - name: Build
+      run: cmake --build build2 -j 2
+
+    - name: Python tests
+      run: cmake --build build2 --target pytest
+
+    - name: C++ tests
+      # TODO: Figure out how to load the DLL on Python 3.8+
+      if: "!(runner.os == 'Windows' && (matrix.python == 3.8 || matrix.python == 3.9 || matrix.python == '3.10' || matrix.python == '3.11-dev' || matrix.python == 'pypy-3.8'))"
+      run: cmake --build build2 --target cpptest
+
+    # Third build - C++17 mode with unstable ABI
+    - name: Configure (unstable ABI)
+      run: >
+        cmake -S . -B build3
+        -DPYBIND11_WERROR=ON
+        -DDOWNLOAD_CATCH=ON
+        -DDOWNLOAD_EIGEN=ON
+        -DCMAKE_CXX_STANDARD=17
+        -DPYBIND11_INTERNALS_VERSION=10000000
+        "-DPYBIND11_TEST_OVERRIDE=test_call_policies.cpp;test_gil_scoped.cpp;test_thread.cpp"
+        ${{ matrix.args }}
+
+    - name: Build (unstable ABI)
+      run: cmake --build build3 -j 2
+
+    - name: Python tests (unstable ABI)
+      run: cmake --build build3 --target pytest
+
+    - name: Interface test
+      run: cmake --build build2 --target test_cmake_build
+
+    # This makes sure the setup_helpers module can build packages using
+    # setuptools
+    - name: Setuptools helpers test
+      run: pytest tests/extra_setuptools
+      if: "!(matrix.runs-on == 'windows-2022')"
+
+
+  deadsnakes:
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+        # TODO: Fails on 3.10, investigate
+        - python-version: "3.9"
+          python-debug: true
+          valgrind: true
+      # - python-version: "3.11-dev"
+      #   python-debug: false
+
+    name: "🐍 ${{ matrix.python-version }}${{ matrix.python-debug && '-dbg' || '' }} (deadsnakes)${{ matrix.valgrind && ' • Valgrind' || '' }} • x64"
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v3
+
+    - name: Setup Python ${{ matrix.python-version }} (deadsnakes)
+      uses: deadsnakes/action@v2.1.1
+      with:
+        python-version: ${{ matrix.python-version }}
+        debug: ${{ matrix.python-debug }}
+
+    - name: Update CMake
+      uses: jwlawson/actions-setup-cmake@v1.12
+
+    - name: Valgrind cache
+      if: matrix.valgrind
+      uses: actions/cache@v3
+      id: cache-valgrind
+      with:
+        path: valgrind
+        key: 3.16.1 # Valgrind version
+
+    - name: Compile Valgrind
+      if: matrix.valgrind && steps.cache-valgrind.outputs.cache-hit != 'true'
+      run: |
+        VALGRIND_VERSION=3.16.1
+        curl https://sourceware.org/pub/valgrind/valgrind-$VALGRIND_VERSION.tar.bz2 -o - | tar xj
+        mv valgrind-$VALGRIND_VERSION valgrind
+        cd valgrind
+        ./configure
+        make -j 2 > /dev/null
+
+    - name: Install Valgrind
+      if: matrix.valgrind
+      working-directory: valgrind
+      run: |
+        sudo make install
+        sudo apt-get update
+        sudo apt-get install libc6-dbg  # Needed by Valgrind
+
+    - name: Prepare env
+      run: |
+        python -m pip install -r tests/requirements.txt
+
+    - name: Configure
+      env:
+        SETUPTOOLS_USE_DISTUTILS: stdlib
+      run: >
+        cmake -S . -B build
+        -DCMAKE_BUILD_TYPE=Debug
+        -DPYBIND11_WERROR=ON
+        -DDOWNLOAD_CATCH=ON
+        -DDOWNLOAD_EIGEN=ON
+        -DCMAKE_CXX_STANDARD=17
+
+    - name: Build
+      run: cmake --build build -j 2
+
+    - name: Python tests
+      run: cmake --build build --target pytest
+
+    - name: C++ tests
+      run: cmake --build build --target cpptest
+
+    - name: Run Valgrind on Python tests
+      if: matrix.valgrind
+      run: cmake --build build --target memcheck
+
+
+  # Testing on clang using the excellent silkeh clang docker images
+  clang:
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        clang:
+          - 3.6
+          - 3.7
+          - 3.9
+          - 7
+          - 9
+          - dev
+        std:
+          - 11
+        include:
+          - clang: 5
+            std: 14
+          - clang: 10
+            std: 20
+          - clang: 10
+            std: 17
+
+    name: "🐍 3 • Clang ${{ matrix.clang }} • C++${{ matrix.std }} • x64"
+    container: "silkeh/clang:${{ matrix.clang }}"
+
+    steps:
+    - uses: actions/checkout@v3
+
+    - name: Add wget and python3
+      run: apt-get update && apt-get install -y python3-dev python3-numpy python3-pytest libeigen3-dev
+
+    - name: Configure
+      shell: bash
+      run: >
+        cmake -S . -B build
+        -DPYBIND11_WERROR=ON
+        -DDOWNLOAD_CATCH=ON
+        -DCMAKE_CXX_STANDARD=${{ matrix.std }}
+        -DPYTHON_EXECUTABLE=$(python3 -c "import sys; print(sys.executable)")
+
+    - name: Build
+      run: cmake --build build -j 2
+
+    - name: Python tests
+      run: cmake --build build --target pytest
+
+    - name: C++ tests
+      run: cmake --build build --target cpptest
+
+    - name: Interface test
+      run: cmake --build build --target test_cmake_build
+
+
+  # Testing NVCC; forces sources to behave like .cu files
+  cuda:
+    runs-on: ubuntu-latest
+    name: "🐍 3.8 • CUDA 11.2 • Ubuntu 20.04"
+    container: nvidia/cuda:11.2.2-devel-ubuntu20.04
+
+    steps:
+    - uses: actions/checkout@v3
+
+    # tzdata will try to ask for the timezone, so set the DEBIAN_FRONTEND
+    - name: Install 🐍 3
+      run: apt-get update && DEBIAN_FRONTEND="noninteractive" apt-get install -y cmake git python3-dev python3-pytest python3-numpy
+
+    - name: Configure
+      run: cmake -S . -B build -DPYBIND11_CUDA_TESTS=ON -DPYBIND11_WERROR=ON -DDOWNLOAD_CATCH=ON
+
+    - name: Build
+      run: cmake --build build -j2 --verbose
+
+    - name: Python tests
+      run: cmake --build build --target pytest
+
+
+# TODO: Internal compiler error - report to NVidia
+#  # Testing CentOS 8 + PGI compilers
+#  centos-nvhpc8:
+#    runs-on: ubuntu-latest
+#    name: "🐍 3 • CentOS8 / PGI 20.11 • x64"
+#    container: centos:8
+#
+#    steps:
+#    - uses: actions/checkout@v3
+#
+#    - name: Add Python 3 and a few requirements
+#      run: yum update -y && yum install -y git python3-devel python3-numpy python3-pytest make environment-modules
+#
+#    - name: Install CMake with pip
+#      run: |
+#        python3 -m pip install --upgrade pip
+#        python3 -m pip install cmake --prefer-binary
+#
+#    - name: Install NVidia HPC SDK
+#      run: >
+#        yum -y install
+#        https://developer.download.nvidia.com/hpc-sdk/20.11/nvhpc-20-11-20.11-1.x86_64.rpm
+#        https://developer.download.nvidia.com/hpc-sdk/20.11/nvhpc-2020-20.11-1.x86_64.rpm
+#
+#    - name: Configure
+#      shell: bash
+#      run: |
+#        source /etc/profile.d/modules.sh
+#        module load /opt/nvidia/hpc_sdk/modulefiles/nvhpc/20.11
+#        cmake -S . -B build -DDOWNLOAD_CATCH=ON -DCMAKE_CXX_STANDARD=14 -DPYTHON_EXECUTABLE=$(python3 -c "import sys; print(sys.executable)")
+#
+#    - name: Build
+#      run: cmake --build build -j 2 --verbose
+#
+#    - name: Python tests
+#      run: cmake --build build --target pytest
+#
+#    - name: C++ tests
+#      run: cmake --build build --target cpptest
+#
+#    - name: Interface test
+#      run: cmake --build build --target test_cmake_build
+
+
+  # Testing on CentOS 7 + PGI compilers, which seems to require more workarounds
+  centos-nvhpc7:
+    runs-on: ubuntu-latest
+    name: "🐍 3 • CentOS7 / PGI 22.3 • x64"
+    container: centos:7
+
+    steps:
+    - uses: actions/checkout@v3
+
+    - name: Add Python 3 and a few requirements
+      run: yum update -y && yum install -y epel-release && yum install -y git python3-devel make environment-modules cmake3 yum-utils
+
+    - name: Install NVidia HPC SDK
+      run: yum-config-manager --add-repo https://developer.download.nvidia.com/hpc-sdk/rhel/nvhpc.repo && yum -y install nvhpc-22.3
+
+    # On CentOS 7, we have to filter a few tests (compiler internal error)
+    # and allow deeper template recursion (not needed on CentOS 8 with a newer
+    # standard library). On some systems, you many need further workarounds:
+    # https://github.com/pybind/pybind11/pull/2475
+    - name: Configure
+      shell: bash
+      run: |
+        source /etc/profile.d/modules.sh
+        module load /opt/nvidia/hpc_sdk/modulefiles/nvhpc/22.3
+        cmake3 -S . -B build -DDOWNLOAD_CATCH=ON \
+                            -DCMAKE_CXX_STANDARD=11 \
+                            -DPYTHON_EXECUTABLE=$(python3 -c "import sys; print(sys.executable)") \
+                            -DCMAKE_CXX_FLAGS="-Wc,--pending_instantiations=0" \
+                            -DPYBIND11_TEST_FILTER="test_smart_ptr.cpp;test_virtual_functions.cpp"
+
+    # Building before installing Pip should produce a warning but not an error
+    - name: Build
+      run: cmake3 --build build -j 2 --verbose
+
+    - name: Install CMake with pip
+      run: |
+        python3 -m pip install --upgrade pip
+        python3 -m pip install pytest
+
+    - name: Python tests
+      run: cmake3 --build build --target pytest
+
+    - name: C++ tests
+      run: cmake3 --build build --target cpptest
+
+    - name: Interface test
+      run: cmake3 --build build --target test_cmake_build
+
+
+  # Testing on GCC using the GCC docker images (only recent images supported)
+  gcc:
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        gcc:
+          - 7
+          - latest
+        std:
+          - 11
+        include:
+          - gcc: 10
+            std: 20
+
+    name: "🐍 3 • GCC ${{ matrix.gcc }} • C++${{ matrix.std }}• x64"
+    container: "gcc:${{ matrix.gcc }}"
+
+    steps:
+    - uses: actions/checkout@v3
+
+    - name: Add Python 3
+      run: apt-get update; apt-get install -y python3-dev python3-numpy python3-pytest python3-pip libeigen3-dev
+
+    - name: Update pip
+      run: python3 -m pip install --upgrade pip
+
+    - name: Update CMake
+      uses: jwlawson/actions-setup-cmake@v1.12
+
+    - name: Configure
+      shell: bash
+      run: >
+        cmake -S . -B build
+        -DPYBIND11_WERROR=ON
+        -DDOWNLOAD_CATCH=ON
+        -DCMAKE_CXX_STANDARD=${{ matrix.std }}
+        -DPYTHON_EXECUTABLE=$(python3 -c "import sys; print(sys.executable)")
+
+    - name: Build
+      run: cmake --build build -j 2
+
+    - name: Python tests
+      run: cmake --build build --target pytest
+
+    - name: C++ tests
+      run: cmake --build build --target cpptest
+
+    - name: Interface test
+      run: cmake --build build --target test_cmake_build
+
+
+  # Testing on ICC using the oneAPI apt repo
+  icc:
+    runs-on: ubuntu-20.04
+    strategy:
+      fail-fast: false
+
+    name: "🐍 3 • ICC latest • x64"
+
+    steps:
+    - uses: actions/checkout@v3
+
+    - name: Add apt repo
+      run: |
+        sudo apt-get update
+        sudo apt-get install -y wget build-essential pkg-config cmake ca-certificates gnupg
+        wget https://apt.repos.intel.com/intel-gpg-keys/GPG-PUB-KEY-INTEL-SW-PRODUCTS-2023.PUB
+        sudo apt-key add GPG-PUB-KEY-INTEL-SW-PRODUCTS-2023.PUB
+        echo "deb https://apt.repos.intel.com/oneapi all main" | sudo tee /etc/apt/sources.list.d/oneAPI.list
+
+    - name: Add ICC & Python 3
+      run: sudo apt-get update; sudo apt-get install -y intel-oneapi-compiler-dpcpp-cpp-and-cpp-classic cmake python3-dev python3-numpy python3-pytest python3-pip
+
+    - name: Update pip
+      run: |
+        set +e; source /opt/intel/oneapi/setvars.sh; set -e
+        python3 -m pip install --upgrade pip
+
+    - name: Install dependencies
+      run: |
+        set +e; source /opt/intel/oneapi/setvars.sh; set -e
+        python3 -m pip install -r tests/requirements.txt
+
+    - name: Configure C++11
+      run: |
+        set +e; source /opt/intel/oneapi/setvars.sh; set -e
+        cmake -S . -B build-11     \
+        -DPYBIND11_WERROR=ON    \
+        -DDOWNLOAD_CATCH=ON     \
+        -DDOWNLOAD_EIGEN=OFF    \
+        -DCMAKE_CXX_STANDARD=11             \
+        -DCMAKE_CXX_COMPILER=$(which icpc)  \
+        -DPYTHON_EXECUTABLE=$(python3 -c "import sys; print(sys.executable)")
+
+    - name: Build C++11
+      run: |
+        set +e; source /opt/intel/oneapi/setvars.sh; set -e
+        cmake --build build-11 -j 2 -v
+
+    - name: Python tests C++11
+      run: |
+        set +e; source /opt/intel/oneapi/setvars.sh; set -e
+        sudo service apport stop
+        cmake --build build-11 --target check
+
+    - name: C++ tests C++11
+      run: |
+        set +e; source /opt/intel/oneapi/setvars.sh; set -e
+        cmake --build build-11 --target cpptest
+
+    - name: Interface test C++11
+      run: |
+        set +e; source /opt/intel/oneapi/setvars.sh; set -e
+        cmake --build build-11 --target test_cmake_build
+
+    - name: Configure C++17
+      run: |
+        set +e; source /opt/intel/oneapi/setvars.sh; set -e
+        cmake -S . -B build-17     \
+        -DPYBIND11_WERROR=ON    \
+        -DDOWNLOAD_CATCH=ON     \
+        -DDOWNLOAD_EIGEN=OFF    \
+        -DCMAKE_CXX_STANDARD=17             \
+        -DCMAKE_CXX_COMPILER=$(which icpc)  \
+        -DPYTHON_EXECUTABLE=$(python3 -c "import sys; print(sys.executable)")
+
+    - name: Build C++17
+      run: |
+        set +e; source /opt/intel/oneapi/setvars.sh; set -e
+        cmake --build build-17 -j 2 -v
+
+    - name: Python tests C++17
+      run: |
+        set +e; source /opt/intel/oneapi/setvars.sh; set -e
+        sudo service apport stop
+        cmake --build build-17 --target check
+
+    - name: C++ tests C++17
+      run: |
+        set +e; source /opt/intel/oneapi/setvars.sh; set -e
+        cmake --build build-17 --target cpptest
+
+    - name: Interface test C++17
+      run: |
+        set +e; source /opt/intel/oneapi/setvars.sh; set -e
+        cmake --build build-17 --target test_cmake_build
+
+
+  # Testing on CentOS (manylinux uses a centos base, and this is an easy way
+  # to get GCC 4.8, which is the manylinux1 compiler).
+  centos:
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        centos:
+          - centos7  # GCC 4.8
+          - stream8
+
+    name: "🐍 3 • CentOS ${{ matrix.centos }} • x64"
+    container: "quay.io/centos/centos:${{ matrix.centos }}"
+
+    steps:
+    - uses: actions/checkout@v3
+
+    - name: Add Python 3
+      run: yum update -y && yum install -y python3-devel gcc-c++ make git
+
+    - name: Update pip
+      run: python3 -m pip install --upgrade pip
+
+    - name: Install dependencies
+      run: |
+        python3 -m pip install cmake -r tests/requirements.txt
+
+    - name: Configure
+      shell: bash
+      run: >
+        cmake -S . -B build
+        -DCMAKE_BUILD_TYPE=MinSizeRel
+        -DPYBIND11_WERROR=ON
+        -DDOWNLOAD_CATCH=ON
+        -DDOWNLOAD_EIGEN=ON
+        -DCMAKE_CXX_STANDARD=11
+        -DPYTHON_EXECUTABLE=$(python3 -c "import sys; print(sys.executable)")
+
+    - name: Build
+      run: cmake --build build -j 2
+
+    - name: Python tests
+      run: cmake --build build --target pytest
+
+    - name: C++ tests
+      run: cmake --build build --target cpptest
+
+    - name: Interface test
+      run: cmake --build build --target test_cmake_build
+
+
+  # This tests an "install" with the CMake tools
+  install-classic:
+    name: "🐍 3.7 • Debian • x86 •  Install"
+    runs-on: ubuntu-latest
+    container: i386/debian:buster
+
+    steps:
+    - uses: actions/checkout@v1  # Required to run inside docker
+
+    - name: Install requirements
+      run: |
+        apt-get update
+        apt-get install -y git make cmake g++ libeigen3-dev python3-dev python3-pip
+        pip3 install "pytest==6.*"
+
+    - name: Configure for install
+      run: >
+        cmake .
+        -DPYBIND11_INSTALL=1 -DPYBIND11_TEST=0
+        -DPYTHON_EXECUTABLE=$(python3 -c "import sys; print(sys.executable)")
+
+    - name: Make and install
+      run: make install
+
+    - name: Copy tests to new directory
+      run: cp -a tests /pybind11-tests
+
+    - name: Make a new test directory
+      run: mkdir /build-tests
+
+    - name: Configure tests
+      run: >
+        cmake ../pybind11-tests
+        -DDOWNLOAD_CATCH=ON
+        -DPYBIND11_WERROR=ON
+        -DPYTHON_EXECUTABLE=$(python3 -c "import sys; print(sys.executable)")
+      working-directory: /build-tests
+
+    - name: Python tests
+      run: make pytest -j 2
+      working-directory: /build-tests
+
+
+  # This verifies that the documentation is not horribly broken, and does a
+  # basic validation check on the SDist.
+  doxygen:
+    name: "Documentation build test"
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v3
+
+    - uses: actions/setup-python@v3
+
+    - name: Install Doxygen
+      run: sudo apt-get install -y doxygen librsvg2-bin # Changed to rsvg-convert in 20.04
+
+    - name: Build docs
+      run: pipx run nox -s docs
+
+    - name: Make SDist
+      run: pipx run nox -s build -- --sdist
+
+    - run: git status --ignored
+
+    - name: Check local include dir
+      run: >
+        ls pybind11;
+        python3 -c "import pybind11, pathlib; assert (a := pybind11.get_include()) == (b := str(pathlib.Path('include').resolve())), f'{a} != {b}'"
+
+    - name: Compare Dists (headers only)
+      working-directory: include
+      run: |
+        python3 -m pip install --user -U ../dist/*.tar.gz
+        installed=$(python3 -c "import pybind11; print(pybind11.get_include() + '/pybind11')")
+        diff -rq $installed ./pybind11
+
+  win32:
+    strategy:
+      fail-fast: false
+      matrix:
+        python:
+        - 3.6
+        - 3.7
+        - 3.8
+        - 3.9
+
+        include:
+          - python: 3.9
+            args: -DCMAKE_CXX_STANDARD=20
+          - python: 3.8
+            args: -DCMAKE_CXX_STANDARD=17
+
+    name: "🐍 ${{ matrix.python }} • MSVC 2019 • x86 ${{ matrix.args }}"
+    runs-on: windows-2019
+
+    steps:
+    - uses: actions/checkout@v3
+
+    - name: Setup Python ${{ matrix.python }}
+      uses: actions/setup-python@v3
+      with:
+        python-version: ${{ matrix.python }}
+        architecture: x86
+
+    - name: Update CMake
+      uses: jwlawson/actions-setup-cmake@v1.12
+
+    - name: Prepare MSVC
+      uses: ilammy/msvc-dev-cmd@v1.10.0
+      with:
+        arch: x86
+
+    - name: Prepare env
+      run: |
+        python -m pip install -r tests/requirements.txt
+
+    # First build - C++11 mode and inplace
+    - name: Configure ${{ matrix.args }}
+      run: >
+        cmake -S . -B build
+        -G "Visual Studio 16 2019" -A Win32
+        -DPYBIND11_WERROR=ON
+        -DDOWNLOAD_CATCH=ON
+        -DDOWNLOAD_EIGEN=ON
+        ${{ matrix.args }}
+    - name: Build C++11
+      run: cmake --build build -j 2
+
+    - name: Python tests
+      run: cmake --build build -t pytest
+
+  win32-debug:
+    strategy:
+      fail-fast: false
+      matrix:
+        python:
+        - 3.8
+        - 3.9
+
+        include:
+          - python: 3.9
+            args: -DCMAKE_CXX_STANDARD=20
+          - python: 3.8
+            args: -DCMAKE_CXX_STANDARD=17
+
+    name: "🐍 ${{ matrix.python }} • MSVC 2019 (Debug) • x86 ${{ matrix.args }}"
+    runs-on: windows-2019
+
+    steps:
+    - uses: actions/checkout@v3
+
+    - name: Setup Python ${{ matrix.python }}
+      uses: actions/setup-python@v3
+      with:
+        python-version: ${{ matrix.python }}
+        architecture: x86
+
+    - name: Update CMake
+      uses: jwlawson/actions-setup-cmake@v1.12
+
+    - name: Prepare MSVC
+      uses: ilammy/msvc-dev-cmd@v1.10.0
+      with:
+        arch: x86
+
+    - name: Prepare env
+      run: |
+        python -m pip install -r tests/requirements.txt
+
+    # First build - C++11 mode and inplace
+    - name: Configure ${{ matrix.args }}
+      run: >
+        cmake -S . -B build
+        -G "Visual Studio 16 2019" -A Win32
+        -DCMAKE_BUILD_TYPE=Debug
+        -DPYBIND11_WERROR=ON
+        -DDOWNLOAD_CATCH=ON
+        -DDOWNLOAD_EIGEN=ON
+        ${{ matrix.args }}
+    - name: Build C++11
+      run: cmake --build build --config Debug -j 2
+
+    - name: Python tests
+      run: cmake --build build --config Debug -t pytest
+
+
+  windows-2022:
+    strategy:
+      fail-fast: false
+      matrix:
+        python:
+        - 3.9
+
+    name: "🐍 ${{ matrix.python }} • MSVC 2022 C++20 • x64"
+    runs-on: windows-2022
+
+    steps:
+    - uses: actions/checkout@v3
+
+    - name: Setup Python ${{ matrix.python }}
+      uses: actions/setup-python@v3
+      with:
+        python-version: ${{ matrix.python }}
+
+    - name: Prepare env
+      run: |
+        python3 -m pip install -r tests/requirements.txt
+
+    - name: Update CMake
+      uses: jwlawson/actions-setup-cmake@v1.12
+
+    - name: Configure C++20
+      run: >
+        cmake -S . -B build
+        -DPYBIND11_WERROR=ON
+        -DDOWNLOAD_CATCH=ON
+        -DDOWNLOAD_EIGEN=ON
+        -DCMAKE_CXX_STANDARD=20
+
+    - name: Build C++20
+      run: cmake --build build -j 2
+
+    - name: Python tests
+      run: cmake --build build --target pytest
+
+    - name: C++20 tests
+      run: cmake --build build --target cpptest -j 2
+
+    - name: Interface test C++20
+      run: cmake --build build --target test_cmake_build
+
+  mingw:
+    name: "🐍 3 • windows-latest • ${{ matrix.sys }}"
+    runs-on: windows-latest
+    defaults:
+      run:
+        shell: msys2 {0}
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - { sys: mingw64, env: x86_64 }
+          - { sys: mingw32, env: i686 }
+    steps:
+    - uses: msys2/setup-msys2@v2
+      with:
+        msystem: ${{matrix.sys}}
+        install: >-
+          git
+          mingw-w64-${{matrix.env}}-gcc
+          mingw-w64-${{matrix.env}}-python-pip
+          mingw-w64-${{matrix.env}}-python-numpy
+          mingw-w64-${{matrix.env}}-python-scipy
+          mingw-w64-${{matrix.env}}-cmake
+          mingw-w64-${{matrix.env}}-make
+          mingw-w64-${{matrix.env}}-python-pytest
+          mingw-w64-${{matrix.env}}-eigen3
+          mingw-w64-${{matrix.env}}-boost
+          mingw-w64-${{matrix.env}}-catch
+
+    - uses: actions/checkout@v3
+
+    - name: Configure C++11
+      # LTO leads to many undefined reference like
+      # `pybind11::detail::function_call::function_call(pybind11::detail::function_call&&)
+      run: cmake -G "MinGW Makefiles" -DCMAKE_CXX_STANDARD=11 -DDOWNLOAD_CATCH=ON -S . -B build
+
+    - name: Build C++11
+      run: cmake --build build -j 2
+
+    - name: Python tests C++11
+      run: cmake --build build --target pytest -j 2
+
+    - name: C++11 tests
+      run: PYTHONHOME=/${{matrix.sys}} PYTHONPATH=/${{matrix.sys}} cmake --build build --target cpptest -j 2
+
+    - name: Interface test C++11
+      run: PYTHONHOME=/${{matrix.sys}} PYTHONPATH=/${{matrix.sys}} cmake --build build --target test_cmake_build
+
+    - name: Clean directory
+      run: git clean -fdx
+
+    - name: Configure C++14
+      run: cmake -G "MinGW Makefiles" -DCMAKE_CXX_STANDARD=14 -DDOWNLOAD_CATCH=ON -S . -B build2
+
+    - name: Build C++14
+      run: cmake --build build2 -j 2
+
+    - name: Python tests C++14
+      run: cmake --build build2 --target pytest -j 2
+
+    - name: C++14 tests
+      run: PYTHONHOME=/${{matrix.sys}} PYTHONPATH=/${{matrix.sys}} cmake --build build2 --target cpptest -j 2
+
+    - name: Interface test C++14
+      run: PYTHONHOME=/${{matrix.sys}} PYTHONPATH=/${{matrix.sys}} cmake --build build2 --target test_cmake_build
+
+    - name: Clean directory
+      run: git clean -fdx
+
+    - name: Configure C++17
+      run: cmake -G "MinGW Makefiles" -DCMAKE_CXX_STANDARD=17 -DDOWNLOAD_CATCH=ON -S . -B build3
+
+    - name: Build C++17
+      run: cmake --build build3 -j 2
+
+    - name: Python tests C++17
+      run: cmake --build build3 --target pytest -j 2
+
+    - name: C++17 tests
+      run: PYTHONHOME=/${{matrix.sys}} PYTHONPATH=/${{matrix.sys}} cmake --build build3 --target cpptest -j 2
+
+    - name: Interface test C++17
+      run: PYTHONHOME=/${{matrix.sys}} PYTHONPATH=/${{matrix.sys}} cmake --build build3 --target test_cmake_build

third_party/pybind11/.github/workflows/configure.yml

@@ -0,0 +1,80 @@
+name: Config
+
+on:
+  workflow_dispatch:
+  pull_request:
+  push:
+    branches:
+      - master
+      - stable
+      - v*
+
+jobs:
+  # This tests various versions of CMake in various combinations, to make sure
+  # the configure step passes.
+  cmake:
+    strategy:
+      fail-fast: false
+      matrix:
+        runs-on: [ubuntu-latest, macos-latest, windows-latest]
+        arch: [x64]
+        cmake: ["3.23"]
+
+        include:
+        - runs-on: ubuntu-latest
+          arch: x64
+          cmake: 3.4
+
+        - runs-on: macos-latest
+          arch: x64
+          cmake: 3.7
+
+        - runs-on: windows-2019
+          arch: x64 # x86 compilers seem to be missing on 2019 image
+          cmake: 3.18
+
+    name: 🐍 3.7 • CMake ${{ matrix.cmake }} • ${{ matrix.runs-on }}
+    runs-on: ${{ matrix.runs-on }}
+
+    steps:
+    - uses: actions/checkout@v3
+
+    - name: Setup Python 3.7
+      uses: actions/setup-python@v3
+      with:
+        python-version: 3.7
+        architecture: ${{ matrix.arch }}
+
+    - name: Prepare env
+      run: python -m pip install -r tests/requirements.txt
+
+    # An action for adding a specific version of CMake:
+    #   https://github.com/jwlawson/actions-setup-cmake
+    - name: Setup CMake ${{ matrix.cmake }}
+      uses: jwlawson/actions-setup-cmake@v1.12
+      with:
+        cmake-version: ${{ matrix.cmake }}
+
+    # These steps use a directory with a space in it intentionally
+    - name: Make build directories
+      run: mkdir "build dir"
+
+    - name: Configure
+      working-directory: build dir
+      shell: bash
+      run: >
+        cmake ..
+        -DPYBIND11_WERROR=ON
+        -DDOWNLOAD_CATCH=ON
+        -DPYTHON_EXECUTABLE=$(python -c "import sys; print(sys.executable)")
+
+    # Only build and test if this was manually triggered in the GitHub UI
+    - name: Build
+      working-directory: build dir
+      if: github.event_name == 'workflow_dispatch'
+      run: cmake --build . --config Release
+
+    - name: Test
+      working-directory: build dir
+      if: github.event_name == 'workflow_dispatch'
+      run: cmake --build . --config Release --target check

third_party/pybind11/.github/workflows/format.yml

@@ -0,0 +1,53 @@
+# This is a format job. Pre-commit has a first-party GitHub action, so we use
+# that: https://github.com/pre-commit/action
+
+name: Format
+
+on:
+  workflow_dispatch:
+  pull_request:
+  push:
+    branches:
+    - master
+    - stable
+    - "v*"
+
+env:
+  FORCE_COLOR: 3
+
+jobs:
+  pre-commit:
+    name: Format
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v3
+    - uses: actions/setup-python@v3
+    - name: Add matchers
+      run: echo "::add-matcher::$GITHUB_WORKSPACE/.github/matchers/pylint.json"
+    - uses: pre-commit/action@v2.0.3
+      with:
+        # Slow hooks are marked with manual - slow is okay here, run them too
+        extra_args: --hook-stage manual --all-files
+
+  clang-tidy:
+    # When making changes here, please also review the "Clang-Tidy" section
+    # in .github/CONTRIBUTING.md and update as needed.
+    name: Clang-Tidy
+    runs-on: ubuntu-latest
+    container: silkeh/clang:12
+    steps:
+    - uses: actions/checkout@v3
+
+    - name: Install requirements
+      run: apt-get update && apt-get install -y python3-dev python3-pytest
+
+    - name: Configure
+      run: >
+        cmake -S . -B build
+        -DCMAKE_CXX_CLANG_TIDY="$(which clang-tidy)"
+        -DDOWNLOAD_EIGEN=ON
+        -DDOWNLOAD_CATCH=ON
+        -DCMAKE_CXX_STANDARD=17
+
+    - name: Build
+      run: cmake --build build -j 2 -- --keep-going

third_party/pybind11/.github/workflows/labeler.yml

@@ -0,0 +1,16 @@
+name: Labeler
+on:
+  pull_request_target:
+    types: [closed]
+
+jobs:
+  label:
+    name: Labeler
+    runs-on: ubuntu-latest
+    steps:
+
+    - uses: actions/labeler@main
+      if: github.event.pull_request.merged == true
+      with:
+        repo-token: ${{ secrets.GITHUB_TOKEN }}
+        configuration-path: .github/labeler_merged.yml

third_party/pybind11/.github/workflows/pip.yml

@@ -0,0 +1,108 @@
+name: Pip
+
+on:
+  workflow_dispatch:
+  pull_request:
+  push:
+    branches:
+    - master
+    - stable
+    - v*
+  release:
+    types:
+    - published
+
+env:
+  PIP_ONLY_BINARY: numpy
+
+jobs:
+  # This builds the sdists and wheels and makes sure the files are exactly as
+  # expected. Using Windows and Python 3.6, since that is often the most
+  # challenging matrix element.
+  test-packaging:
+    name: 🐍 3.6 • 📦 tests • windows-latest
+    runs-on: windows-latest
+
+    steps:
+    - uses: actions/checkout@v3
+
+    - name: Setup 🐍 3.6
+      uses: actions/setup-python@v3
+      with:
+        python-version: 3.6
+
+    - name: Prepare env
+      run: |
+        python -m pip install -r tests/requirements.txt
+
+    - name: Python Packaging tests
+      run: pytest tests/extra_python_package/
+
+
+  # This runs the packaging tests and also builds and saves the packages as
+  # artifacts.
+  packaging:
+    name: 🐍 3.8 • 📦 & 📦 tests • ubuntu-latest
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v3
+
+    - name: Setup 🐍 3.8
+      uses: actions/setup-python@v3
+      with:
+        python-version: 3.8
+
+    - name: Prepare env
+      run: |
+        python -m pip install -r tests/requirements.txt build twine
+
+    - name: Python Packaging tests
+      run: pytest tests/extra_python_package/
+
+    - name: Build SDist and wheels
+      run: |
+        python -m build
+        PYBIND11_GLOBAL_SDIST=1 python -m build
+
+    - name: Check metadata
+      run: twine check dist/*
+
+    - name: Save standard package
+      uses: actions/upload-artifact@v3
+      with:
+        name: standard
+        path: dist/pybind11-*
+
+    - name: Save global package
+      uses: actions/upload-artifact@v3
+      with:
+        name: global
+        path: dist/pybind11_global-*
+
+
+
+  # When a GitHub release is made, upload the artifacts to PyPI
+  upload:
+    name: Upload to PyPI
+    runs-on: ubuntu-latest
+    if: github.event_name == 'release' && github.event.action == 'published'
+    needs: [packaging]
+
+    steps:
+    - uses: actions/setup-python@v3
+
+    # Downloads all to directories matching the artifact names
+    - uses: actions/download-artifact@v3
+
+    - name: Publish standard package
+      uses: pypa/gh-action-pypi-publish@v1.5.0
+      with:
+        password: ${{ secrets.pypi_password }}
+        packages_dir: standard/
+
+    - name: Publish global package
+      uses: pypa/gh-action-pypi-publish@v1.5.0
+      with:
+        password: ${{ secrets.pypi_password_global }}
+        packages_dir: global/

third_party/pybind11/.github/workflows/upstream.yml

@@ -0,0 +1,112 @@
+
+name: Upstream
+
+on:
+  workflow_dispatch:
+  pull_request:
+
+concurrency:
+  group: upstream-${{ github.ref }}
+  cancel-in-progress: true
+
+env:
+  PIP_ONLY_BINARY: numpy
+
+jobs:
+  standard:
+    name: "🐍 3.11 dev • ubuntu-latest • x64"
+    runs-on: ubuntu-latest
+    if: "contains(github.event.pull_request.labels.*.name, 'python dev')"
+
+    steps:
+    - uses: actions/checkout@v3
+
+    - name: Setup Python 3.11
+      uses: actions/setup-python@v3
+      with:
+        python-version: "3.11-dev"
+
+    - name: Setup Boost (Linux)
+      if: runner.os == 'Linux'
+      run: sudo apt-get install libboost-dev
+
+    - name: Update CMake
+      uses: jwlawson/actions-setup-cmake@v1.12
+
+    - name: Prepare env
+      run: |
+        python -m pip install -r tests/requirements.txt
+
+    - name: Setup annotations on Linux
+      if: runner.os == 'Linux'
+      run: python -m pip install pytest-github-actions-annotate-failures
+
+    # First build - C++11 mode and inplace
+    - name: Configure C++11
+      run: >
+        cmake -S . -B .
+        -DPYBIND11_WERROR=ON
+        -DDOWNLOAD_CATCH=ON
+        -DDOWNLOAD_EIGEN=ON
+        -DCMAKE_CXX_STANDARD=11
+
+    - name: Build C++11
+      run: cmake --build . -j 2
+
+    - name: Python tests C++11
+      run: cmake --build . --target pytest -j 2
+
+    - name: C++11 tests
+      run: cmake --build .  --target cpptest -j 2
+
+    - name: Interface test C++11
+      run: cmake --build . --target test_cmake_build
+
+    - name: Clean directory
+      run: git clean -fdx
+
+    # Second build - C++17 mode and in a build directory
+    - name: Configure C++17
+      run: >
+        cmake -S . -B build2
+        -DPYBIND11_WERROR=ON
+        -DDOWNLOAD_CATCH=ON
+        -DDOWNLOAD_EIGEN=ON
+        -DCMAKE_CXX_STANDARD=17
+        ${{ matrix.args }}
+        ${{ matrix.args2 }}
+
+    - name: Build
+      run: cmake --build build2 -j 2
+
+    - name: Python tests
+      run: cmake --build build2 --target pytest
+
+    - name: C++ tests
+      run: cmake --build build2 --target cpptest
+
+    # Third build - C++17 mode with unstable ABI
+    - name: Configure (unstable ABI)
+      run: >
+        cmake -S . -B build3
+        -DPYBIND11_WERROR=ON
+        -DDOWNLOAD_CATCH=ON
+        -DDOWNLOAD_EIGEN=ON
+        -DCMAKE_CXX_STANDARD=17
+        -DPYBIND11_INTERNALS_VERSION=10000000
+        "-DPYBIND11_TEST_OVERRIDE=test_call_policies.cpp;test_gil_scoped.cpp;test_thread.cpp"
+        ${{ matrix.args }}
+
+    - name: Build (unstable ABI)
+      run: cmake --build build3 -j 2
+
+    - name: Python tests (unstable ABI)
+      run: cmake --build build3 --target pytest
+
+    - name: Interface test
+      run: cmake --build build2 --target test_cmake_build
+
+    # This makes sure the setup_helpers module can build packages using
+    # setuptools
+    - name: Setuptools helpers test
+      run: pytest tests/extra_setuptools