* ci: releases

* docs: minor update form @wjakob

* fix: enforce reasonable version of setuptools

* Initializing PyModuleDef object with PyModuleDef_HEAD_INIT.

Python 3.8 documentation: m_base - Always initialize this member to PyModuleDef_HEAD_INIT.

Long-standing (since first github commit in 2015), inconsequential bug.

Also removing inconsequential Py_INCREF(def): PyModule_Create() resets the reference count to 1.

* git rebase master

* moving static PyModuleDef declaration to global scope, as requested by @wjakob

* renaming the two new macros, to start with PYBIND11_DETAIL_MODULE

Fixed in #2510 but reintroduced on one line by #2126

Closes #2515, found by @rhjdjong

This changes enum reprs to look like `<Enum.name: value>` similarly to
the Python enum module.

This keeps the str of enums as `Enum.name`, like the Python enum module.

* Include what is used

* Separated the C++ standard library headers and the project headers

* Reordering includes

* fix: AppleClang 12 new warning

* Fix: AppleClang X.X.0 will not trigger this warning

* ci: fix broken documenation test (works on RtD)

* docs: docs link incorrect

* docs: read version from pybind11 file

* docs: show full PEP 440 version everywhere

This now tests the old form too, and fixes the bug introduced.

* docs: installing section

* docs: feedback from @wjakob

Support C++20. For backwards compatibility, we provide an alias for the old name.
This change is necessary to easily avoid errors when a compiler thinks
`module` is used as a keyword.

* refactor: drop mkdoc

* docs: update changelog

* 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

* refactor: replace .get_type with type::handle_of

* refactor: use impl for handle_of

* fix: deprecate h.get_type()

* Add vcpkg installation instructions

* Casing

* Move instructions

Co-authored-by: Henry Fredrick Schreiner <henry.fredrick.schreiner@cern.ch>

* fix: use OVERRIDE instead of OVERLOAD

* docs: more accurate statement

Change base parameter type in register_exception and exception constructor from PyObject* to handle (#2467)

* Change base parameter type in register_exception and excepion constructor from PyObject* to handle

* Fix compilation error passing `handle` to `PyObject*`

```
/pybind11/include/pybind11/iostream.h:71:9: warning: Call to virtual method 'pythonbuf::sync' during destruction bypasses virtual dispatch [clang-analyzer-optin.cplusplus.VirtualCall]
        sync();
        ^
/pybind11/tests/test_iostream.cpp:72:5: note: Calling '~scoped_ostream_redirect'
    });
```

Resolve empty statement warning when using PYBIND11_OVERLOAD_PURE_NAME and PYBIND11_OVERLOAD_PURE (#2325)

* Wrap PYBIND11_OVERLOAD_NAME and PYBIND11_OVERLOAD_PURE_NAME in do { ... } while (false), and resolve trailing semicolon

* Deprecate PYBIND11_OVERLOAD_* and get_overload in favor of PYBIND11_OVERRIDE_* and get_override

* Correct erroneous usage of 'overload' instead of 'override' in the implementation and internals

* Fix tests to use non-deprecated PYBIND11_OVERRIDE_* macros

* Update docs to use override instead of overload where appropriate, and add warning about deprecated aliases

* Add semicolons to deprecated PYBIND11_OVERLOAD macros to match original behavior

* Remove deprecation of PYBIND11_OVERLOAD_* macros and get_overload

* Add note to changelog and upgrade guide

Stop py::array_t arguments from accepting arrays that do not match the C- or F-contiguity flags (#2484)

* Stop py::array_t arguments from accepting arrays that do not match the C- or F-contiguity flags

* Add trivially-contiguous arrays to the tests

* feat: type<T>()

* refactor: using py::type as class

* refactor: py::object as base

* wip: tigher api

* refactor: fix conversion and limit API further

* docs: some added notes from @EricCousineau-TRI

* refactor: use py::type::of

Why only for pointers? Because C casts are hard to grep for.

* Added guards to the includes

Added new CI config

Added new trigger

Changed CI workflow name

Debug CI

Debug CI

Debug CI

Debug CI

Added flags fro PGI

Disable Eigen

Removed tests that fail

Uncomment lines

* fix: missing include

fix: minor style cleanup

tests: support skipping

ci: remove and tighten a bit

fix: try msvc workaround for pgic

* tests: split up prealoc tests

* fix: PGI compiler fix

* fix: PGI void_t only

* fix: try to appease nvcc

* ci: better ordering for slow tests

* ci: minor improvements to testing

* ci: Add NumPy to testing

* ci: Eigen generates CUDA warnings / PGI errors

* Added CentOS7 back for a moment

* Fix YAML

* ci: runs-on missing

* centos7 is missing pytest

* ci: use C++11 on CentOS 7

* ci: test something else

* Try just adding flags on CentOS 7

* fix: CentOS 7

* refactor: move include to shared location

* Added verbose flag

* Try to use system cmake3 on CI

* Try to use system cmake3 on CI, attempt2

* Try to use system cmake3 on CI, attempt3

* tests: not finding pytest should be a warning, not a fatal error

* tests: cleanup

* Weird issue?

* fix: final polish

Co-authored-by: Andrii Verbytskyi <andrii.verbytskyi@mpp.mpg.de>
Co-authored-by: Henry Schreiner <henryschreineriii@gmail.com>
Co-authored-by: Andrii Verbytskyi <averbyts@cern.ch>