GitLab

* `#error BYE_BYE_GOLDEN_SNAKE`

* Removing everything related to 2.7 from ci.yml

* Commenting-out Centos7

* Removing `PYTHON: 27` from .appveyor.yml

* "PY2" removal, mainly from tests. C++ code is not touched.

* Systematic removal of `u` prefix from `u"..."` and `u'...'` literals. Collateral cleanup of a couple minor other things.

* Cleaning up around case-insensitive hits for `[^a-z]py.*2` in tests/.

* Removing obsolete Python 2 mention in compiling.rst

* Proper `#error` for Python 2.

* Using PY_VERSION_HEX to guard `#error "PYTHON 2 IS NO LONGER SUPPORTED.`

* chore: bump pre-commit

* style: run pre-commit for pyupgrade 3+

* tests: use sys.version_info, not PY

* chore: more Python 2 removal

* Uncommenting Centos7 block (PR #3691 showed that it is working again).

* Update pre-commit hooks

* Fix pre-commit hook

* refactor: remove Python 2 from CMake

* refactor: remove Python 2 from setup code

* refactor: simplify, better static typing

* feat: fail with nice messages

* refactor: drop Python 2 C++ code

* docs: cleanup for Python 3

* revert: intree

revert: intree

* docs: minor touchup to py2 statement
Co-authored-by: Henry Schreiner <henryschreineriii@gmail.com>
Co-authored-by: Aaron Gokaslan <skylion.aaron@gmail.com>

* Splitting out pybind11/stl/filesystem.h.

To solve breakages like: https://github.com/deepmind/open_spiel/runs/2999582108

Mostly following the suggestion here: https://github.com/pybind/pybind11/pull/2730#issuecomment-750507575

Except using pybind11/stl/filesystem.h instead of pybind11/stlfs.h, as decided via chat.

stl.h restored to the exact state before merging PR #2730 via:
```
git checkout 733f8de2 stl.h
```

* Properly including new stl subdirectory in pip wheel config.

This now passes interactively:
```
pytest tests/extra_python_package/
```

* iwyu cleanup.

iwyuh.py -c -std=c++17 -DPYBIND11_TEST_BOOST -Ipybind11/include -I/usr/include/python3.9 -I/usr/include/eigen3 include/pybind11/stl/filesystem.h

* Adding PYBIND11_HAS_FILESYSTEM_IS_OPTIONAL.

* Eliminating else after return.

* Splitting out detail/type_caster_base.h from cast.h.
* Include cleanup guided by include-what-you-use 0.12 based on clang version 9.0.1-11.

* feat: basic typing support

* docs: mention syncing as suggested by @rwgk

* docs: update changelog

* docs: copy of warning in limitations

* feat: setup.py redesign and helpers

* refactor: simpler design with two outputs

* refactor: helper file update and Windows support

* fix: review points from @YannickJadoul

* refactor: fixes to naming and more docs

* feat: more customization points

* feat: add entry point pybind11-config

* refactor: Try Extension-focused method

* refactor: rename alt/inplace to global

* fix: allow usage with git modules, better docs

* feat: global as an extra (@YannickJadoul's suggestion)

* feat: single version location

* fix: remove the requirement that setuptools must be imported first

* fix: some review points from @wjacob

* fix: use .in, add procedure to docs

* refactor: avoid monkeypatch copy

* docs: minor typos corrected

* fix: minor points from @YannickJadoul

* fix: typo on Windows C++ mode

* fix: MSVC 15 update 3+ have c++14 flag

See <https://docs.microsoft.com/en-us/cpp/build/reference/std-specify-language-standard-version?view=vs-2019>

* docs: discuss making SDists by hand

* ci: use pep517.build instead of manual setup.py

* refactor: more comments from @YannickJadoul

* docs: updates from @ktbarrett

* fix: change to newly recommended tool instead of pep517.build

This was intended as a proof of concept; build seems to be the correct replacement.

See https://github.com/pypa/pep517/pull/83

* docs: updates from @wjakob

* refactor: dual version locations

* docs: typo spotted by @wjakob