* Always call PyNumber_Index when casting from Python to a C++ integral type, also pre-3.8
* Fixed on PyPy
* Simplify use of PyNumber_Index, following @rwgk's idea, and ignore warnings in >=3.8
* Reproduce mismatch between pre-3.8 and post-3.8 behavior on __index__ throwing TypeError
* Fix tests on 3.6 <= Python < 3.8
* No, I don't have an uninitialized variable
* Fix use of __index__ on Python 2
* Make types in test_int_convert more ~boring~ descriptive
* Force the builtin module key to be the correct type.
Previously it was always going to be a std::string which converted into
unicode. Python 2 appears to want module keys to be normal str types, so
this was breaking code that expected plain string types in the
builtins.keys() data structure
* Add a simple unit test to ensure all built-in keys are str
* Update the unit test so it will also run on pypy
* Run pre-commit.
Co-authored-by: Jesse Clemens <jesse.clemens@sony.com>
* CI: Intel icc/icpc via oneAPI
Add testing for Intel icc/icpc via the oneAPI images.
Intel oneAPI is in a late beta stage, currently shipping
oneAPI beta09 with ICC 20.2.
CI: Skip Interpreter Tests for Intel
Cannot find how to add this, neiter the package `libc6-dev` nor
`intel-oneapi-mkl-devel` help when installed to solve this:
```
-- Looking for C++ include pthread.h
-- Looking for C++ include pthread.h - not found
CMake Error at /__t/cmake/3.18.4/x64/cmake-3.18.4-Linux-x86_64/share/cmake-3.18/Modules/FindPackageHandleStandardArgs.cmake:165 (message):
Could NOT find Threads (missing: Threads_FOUND)
Call Stack (most recent call first):
/__t/cmake/3.18.4/x64/cmake-3.18.4-Linux-x86_64/share/cmake-3.18/Modules/FindPackageHandleStandardArgs.cmake:458 (_FPHSA_FAILURE_MESSAGE)
/__t/cmake/3.18.4/x64/cmake-3.18.4-Linux-x86_64/share/cmake-3.18/Modules/FindThreads.cmake:234 (FIND_PACKAGE_HANDLE_STANDARD_ARGS)
tests/test_embed/CMakeLists.txt:17 (find_package)
```
CI: libc6-dev from GCC for ICC
CI: Run bare metal for oneAPI
CI: Ubuntu 18.04 for oneAPI
CI: Intel +Catch -Eigen
CI: CMake from Apt (ICC tests)
CI: Replace Intel Py with GCC Py
CI: Intel w/o GCC's Eigen
CI: ICC with verbose make
[Debug] Find core dump
tests: use arg{} instead of arg() for Intel
tests: adding a few more missing {}
fix: sync with @tobiasleibner's branch
fix: try ubuntu 20-04
fix: drop exit 1
docs: Apply suggestions from code review
Co-authored-by: Tobias Leibner <tobias.leibner@googlemail.com>
Workaround for ICC enable_if issues
Another workaround for ICC's enable_if issues
fix error in previous commit
Disable one test for the Intel compiler in C++17 mode
Add back one instance of py::arg().noconvert()
Add NOLINT to fix clang-tidy check
Work around for ICC internal error in PYBIND11_EXPAND_SIDE_EFFECTS in C++17 mode
CI: Intel ICC with C++17
docs: pybind11/numpy.h does not require numpy at build time. (#2720)
This is nice enough to be mentioned explicitly in the docs.
docs: Update warning about Python 3.9.0 UB, now that 3.9.1 has been released (#2719)
Adjusting `type_caster<std::reference_wrapper<T>>` to support const/non-const propagation in `cast_op`. (#2705)
* Allow type_caster of std::reference_wrapper<T> to be the same as a native reference.
Before, both std::reference_wrapper<T> and std::reference_wrapper<const T> would
invoke cast_op<type>. This doesn't allow the type_caster<> specialization for T
to distinguish reference_wrapper types from value types.
After, the type_caster<> specialization invokes cast_op<type&>, which allows
reference_wrapper to behave in the same way as a native reference type.
* Add tests/examples for std::reference_wrapper<const T>
* Add tests which use mutable/immutable variants
This test is a chimera; it blends the pybind11 casters with a custom
pytype implementation that supports immutable and mutable calls.
In order to detect the immutable/mutable state, the cast_op needs
to propagate it, even through e.g. std::reference<const T>
Note: This is still a work in progress; some things are crashing,
which likely means that I have a refcounting bug or something else
missing.
* Add/finish tests that distinguish const& from &
Fixes the bugs in my custom python type implementation,
demonstrate test that requires const& and reference_wrapper<const T>
being treated differently from Non-const.
* Add passing a const to non-const method.
* Demonstrate non-const conversion of reference_wrapper in tests.
Apply formatting presubmit check.
* Fix build errors from presubmit checks.
* Try and fix a few more CI errors
* More CI fixes.
* More CI fixups.
* Try and get PyPy to work.
* Additional minor fixups. Getting close to CI green.
* More ci fixes?
* fix clang-tidy warnings from presubmit
* fix more clang-tidy warnings
* minor comment and consistency cleanups
* PyDECREF -> Py_DECREF
* copy/move constructors
* Resolve codereview comments
* more review comment fixes
* review comments: remove spurious &
* Make the test fail even when the static_assert is commented out.
This expands the test_freezable_type_caster a bit by:
1/ adding accessors .is_immutable and .addr to compare identity
from python.
2/ Changing the default cast_op of the type_caster<> specialization
to return a non-const value. In normal codepaths this is a reasonable
default.
3/ adding roundtrip variants to exercise the by reference, by pointer
and by reference_wrapper in all call paths. In conjunction with 2/, this
demonstrates the failure case of the existing std::reference_wrpper conversion,
which now loses const in a similar way that happens when using the default cast_op_type<>.
* apply presubmit formatting
* Revert inclusion of test_freezable_type_caster
There's some concern that this test is a bit unwieldly because of the use
of the raw <Python.h> functions. Removing for now.
* Add a test that validates const references propagation.
This test verifies that cast_op may be used to correctly detect
const reference types when used with std::reference_wrapper.
* mend
* Review comments based changes.
1. std::add_lvalue_reference<type> -> type&
2. Simplify the test a little more; we're never returning the ConstRefCaster
type so the class_ definition can be removed.
* formatted files again.
* Move const_ref_caster test to builtin_casters
* Review comments: use cast_op and adjust some comments.
* Simplify ConstRefCasted test
I like this version better as it moves the assertion that matters
back into python.
ci: drop pypy2 linux, PGI 20.7, add Python 10 dev (#2724)
* ci: drop pypy2 linux, add Python 10 dev
* ci: fix mistake
* ci: commented-out PGI 20.11, drop 20.7
fix: regression with installed pybind11 overriding local one (#2716)
* fix: regression with installed pybind11 overriding discovered one
Closes#2709
* docs: wording incorrect
style: remove redundant instance->owned = true (#2723)
which was just before set to True in instance->allocate_layout()
fix: also throw in the move-constructor added by the PYBIND11_OBJECT macro, after the argument has been moved-out (if necessary) (#2701)
Make args_are_all_* ICC workarounds unconditional
Disable test_aligned on Intel ICC
Fix test_aligned on Intel ICC
Skip test_python_alreadyset_in_destructor on Intel ICC
Fix test_aligned again
ICC CI: Downgrade pytest
pytest 6 does not capture the `discard_as_unraisable` stderr and
just writes a warning with its content instead.
* refactor: simpler Intel workaround, suggested by @laramiel
* fix: try version with impl to see if it is easier to compile
* docs: update README for ICC
Co-authored-by: Axel Huebl <axel.huebl@plasma.ninja>
Co-authored-by: Henry Schreiner <henryschreineriii@gmail.com>
* Only allow integer type_caster to call __int__ or __index__ method when conversion is allowed
* Remove tests for __index__ as this seems to only be used to convert to int in 3.8+
* Take both `int` and `long` types into account for Python 2
* Add test_numpy_int_convert to assert tests currently fail, even though np.intc has an __index__ method
* Also consider __index__ as noconvert to a C++ integer
* New-style classes for Python 2.7; sigh
* Add some tests on types with custom __index__ method
* Ignore some tests in Python <3.8
* Update comment about conversion from np.float32 to C++ int
* Workaround difference between CPython and PyPy's different PyIndex_Check (unnoticed because we currently don't have PyPy >= 3.8)
* Avoid ICC segfault with py::arg()
* Plug leaking function_record objects when exceptions are thrown
* Plug leak of strdup'ed strings in function_record
* Some extra comments about the function_record ownership dance
* Clean up the function_record better, in case of exceptions
* Demonstrate some extra function_record leaks
* Change DeleteStrings template argument to free_strings runtime argument in destruct(function_record *)
* Zero-state unique_function_record deleter object
* Clarify rvalue reference to unique_ptr parameter in initialize_generic
* Use push_back with const char * instead of emplace_back
* Fix a clang warning from [-Wshadow-field-in-constructor-modified]
warning: modifying constructor parameter 'flag' that shadows a field of 'set_flag' [-Wshadow-field-in-constructor-modified]
* Change name based on review
* Update attr.h: fix a warning found by static code analyzer
Update attr.h: fix a warning found by Visual Studio static code analyzer
Severity:Warning
Code:C6323
Description: Use of arithmetic operator on Boolean type(s).
Location: C:\src\onnxruntime\debug\pybind11\src\pybind11\include\pybind11\attr.h:547
* Update include/pybind11/attr.h
Co-authored-by: Henry Schreiner <HenrySchreinerIII@gmail.com>
* Update attr.h
Co-authored-by: Henry Schreiner <HenrySchreinerIII@gmail.com>
* Fix leak in the test_copy_move::test_move_fallback
* Fix leaking PyMethodDef in test_class::test_implicit_conversion_life_support
* Plumb leak in test_buffer, occuring when a mutable buffer is requested for a read-only object, and enable test_buffer.py
* Fix weird return_value_policy::reference in test_stl_binders, and enable those tests
* Cleanup nodelete holder objects in test_smart_ptr, and enable those tests
* Avoid thread termination in scoped_released
Do not call `PyEval_RestoreThread()` from `~gil_scoped_release()` if python runtime is finalizing, as it will result in thread termination in Python runtime newer than 3.6, as documented in https://docs.python.org/3/c-api/init.html#c.PyEval_RestoreThread
Similarly do not call `PyThreadState_DeleteCurrent` from `~gil_scoped_acquire()` if runtime is finalizing.
Discovered while debugging PyTorch crash using Python-3.9 described in https://github.com/pytorch/pytorch/issues/47776
* Simplify _Py_IsFinalizing() availability check
* Fix typo
* Add version agnostic `detail::finalization_guard()`
* Move `finalization_guard` to detail/common.h
And rename it to `is_finalizing`
* Move `is_finalizing()` back to pybind11.h
* Simplify `is_finalizing()` check
One should follow documentation rather than make any assumptions
* feat: disarm
* docs: fix comment
Co-authored-by: Henry Schreiner <henryschreineriii@gmail.com>
* Allow type_caster of std::reference_wrapper<T> to be the same as a native reference.
Before, both std::reference_wrapper<T> and std::reference_wrapper<const T> would
invoke cast_op<type>. This doesn't allow the type_caster<> specialization for T
to distinguish reference_wrapper types from value types.
After, the type_caster<> specialization invokes cast_op<type&>, which allows
reference_wrapper to behave in the same way as a native reference type.
* Add tests/examples for std::reference_wrapper<const T>
* Add tests which use mutable/immutable variants
This test is a chimera; it blends the pybind11 casters with a custom
pytype implementation that supports immutable and mutable calls.
In order to detect the immutable/mutable state, the cast_op needs
to propagate it, even through e.g. std::reference<const T>
Note: This is still a work in progress; some things are crashing,
which likely means that I have a refcounting bug or something else
missing.
* Add/finish tests that distinguish const& from &
Fixes the bugs in my custom python type implementation,
demonstrate test that requires const& and reference_wrapper<const T>
being treated differently from Non-const.
* Add passing a const to non-const method.
* Demonstrate non-const conversion of reference_wrapper in tests.
Apply formatting presubmit check.
* Fix build errors from presubmit checks.
* Try and fix a few more CI errors
* More CI fixes.
* More CI fixups.
* Try and get PyPy to work.
* Additional minor fixups. Getting close to CI green.
* More ci fixes?
* fix clang-tidy warnings from presubmit
* fix more clang-tidy warnings
* minor comment and consistency cleanups
* PyDECREF -> Py_DECREF
* copy/move constructors
* Resolve codereview comments
* more review comment fixes
* review comments: remove spurious &
* Make the test fail even when the static_assert is commented out.
This expands the test_freezable_type_caster a bit by:
1/ adding accessors .is_immutable and .addr to compare identity
from python.
2/ Changing the default cast_op of the type_caster<> specialization
to return a non-const value. In normal codepaths this is a reasonable
default.
3/ adding roundtrip variants to exercise the by reference, by pointer
and by reference_wrapper in all call paths. In conjunction with 2/, this
demonstrates the failure case of the existing std::reference_wrpper conversion,
which now loses const in a similar way that happens when using the default cast_op_type<>.
* apply presubmit formatting
* Revert inclusion of test_freezable_type_caster
There's some concern that this test is a bit unwieldly because of the use
of the raw <Python.h> functions. Removing for now.
* Add a test that validates const references propagation.
This test verifies that cast_op may be used to correctly detect
const reference types when used with std::reference_wrapper.
* mend
* Review comments based changes.
1. std::add_lvalue_reference<type> -> type&
2. Simplify the test a little more; we're never returning the ConstRefCaster
type so the class_ definition can be removed.
* formatted files again.
* Move const_ref_caster test to builtin_casters
* Review comments: use cast_op and adjust some comments.
* Simplify ConstRefCasted test
I like this version better as it moves the assertion that matters
back into python.
This line had two bugs:
1. It declares `py::detail::class_` as `friend`.
2. After fixing that, we would have to change it to
`template <typename, typename...>`
The first one was introduced ~5 years ago, when a large refactoring was
made, probably as an intermediate step during refactoring.
The second was made when `generic_type` was made to be agnostic with
respect to the order of `py::class_` template parameters.
We're removing the declaration altogether, because it was never relied
on. This is what makes me think that it was an intermediate step in
refactoring that shouldn't have ended up in commit history.
* demo kwarg with none(false)
* Reorder and extend tests for arg::none(false) in test_methods_and_attributes.py::test_accepts_none
* Fix arg::none() for keyword arguments
* Add changelog note
* Fix names of no_none_kw test functions
Co-authored-by: Yannick Jadoul <yannick.jadoul@belgacom.net>
* Demonstrate test_factory_constructors.py failure without functional changes from #2335
* Revert "Demonstrate test_factory_constructors.py failure without functional changes from #2335"
This reverts commit ca33a8021fc2a3617c3356b188796528f4594419.
* Fix test crash where registered Python type gets garbage collected
* Clean up some more internal structures when class objects go out of scope
* Reduce length of std::erase_if-in-C++20 comment
* Clean up code for cleaning up type internals
* Move cleaning up of type info in internals to tp_dealloc on pybind11_metaclass
* add support for LLVM compiler
* Update include/pybind11/pybind11.h
__forced_unwind libc++ vs libstdc++
Co-authored-by: Henry Schreiner <HenrySchreinerIII@gmail.com>
Co-authored-by: Henry Schreiner <HenrySchreinerIII@gmail.com>
* Deprecated public constructors of module
* Turn documentation comment of module_::add_object into valid doxygen documentation
* Move definition of PYBIND11_DETAIL_MODULE_STATIC_DEF and PYBIND11_DETAIL_MODULE_CREATE macros up
* Move detail::create_top_level_module to module_::create_extension_module, and unify Python 2 and 3 signature again
* Throw error_already_set if module creation fails in module_::create_extension_module
* Mention module_::create_extension_module in deprecation warning message of module_::module_
* Check scope's __dict__ instead of using hasattr when registering classes and exceptions, to allow registering the same name in a derived class scope
* Extend test_base_and_derived_nested_scope test
* Add tests on error being thrown registering duplicate classes
* Circumvent bug with combination of test_class.py::test_register_duplicate_class and test_factory_constructors.py::test_init_factory_alias
* fix: PYBIND11_OBJECT could only be used inside the pybind11 namespace (regression)
* docs: add changelog for conversion protection change
* ci: update to Python 3.9
* Fail on passing py::object with wrong Python type to py::object subclass using PYBIND11_OBJECT macro
* Split off test_non_converting_constructors from test_constructors
* Fix test_as_type, as py::type constructor now throws an error itself if the argument is not a type
* Replace tp_name access by pybind11::detail::get_fully_qualified_tp_name
* Move forward-declaration of get_fully_qualified_tp_name to detail/common.h
* Don't add the builtins module name in get_fully_qualified_tp_name for PyPy
* Add PYBIND11_BUILTINS_MODULE macro, and use it in get_fully_qualified_tp_name
* Remove code inside 'PYPY_VERSION_NUM < 0x06000000' preprocessor if branch
* fix: more cleanup
* Remove more references to PyPy 5.7 and 5.9 in the docs
* Update comment on PyUnicode_UTF* in PyPy
Co-authored-by: Henry Schreiner <henryschreineriii@gmail.com>
* tests: New test for ctypes buffers (pybind#2502)
* fix: fix buffer_info segfault on views with no stride (pybind11#2502)
* Explicit conversions in buffer_info to make clang happy (pybind#2502)
* Another explicit cast in buffer_info constructor for clang (pybind#2502)
* Simpler implementation of buffer_info constructor from Py_buffer.
* Move test_ctypes_buffer into test_buffers
* Comment on why view->strides may be NULL (and fix some whitespace)
* Use c_strides() instead of zero when view->strides is NULL.
c_strides and f_strides are moved from numpy.h (py::array)
to buffer_info.h (py::detail) so they can be used from the
buffer_info Py_buffer constructor.
* Increase ctypes buffer test coverage in test_buffers.
* Split ctypes tests and skip one which is broken in PyPy2.
* Allow function/functor passed to py::vectorize to return void
* Stealing @sizmailov's test and fixing unused argument warning
* Add missing std::move()
RVO doesn't work here because function return type is different from
actual returned type
* remove extra EOL
* docs: add a few details
* chore: pre-commit autoupdate
* Remove array_iterator, array_begin, and array_end (in detail namespace)
Co-authored-by: Sergei Izmailov <sergei.a.izmailov@gmail.com>
Co-authored-by: Henry Schreiner <henryschreineriii@gmail.com>
* Add tests demonstrating the problem with deregistering pybind11 instances
* Fix deregistering of different pybind11 instance from internals
Co-authored-by: Yannick Jadoul <yannick.jadoul@belgacom.net>
Co-authored-by: Blistic <wots_wot@hotmail.com>
* 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
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.
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.
* 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
* Change base parameter type in register_exception and excepion constructor from PyObject* to handle
* Fix compilation error passing `handle` to `PyObject*`
* 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
* 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
* 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>
* Add check if `str(handle)` correctly converted the object, and throw py::error_already_set if not
* Fix tests on Python 3
* Apply @rwgk's fixes to cherry-picked commits from #2392
The variables PYBIND11_HAS_OPTIONAL, PYBIND11_HAS_EXP_OPTIONAL, PYBIND11_HAS_VARIANT,
__clang__, __APPLE__ were not checked for defined in a minortity of instances.
If the project using pybind11 sets -Wundef, the warnings will show.
The test build is also modified to catch the problem.
* fix: support nvcc and test
* fixup! fix: support nvcc and test
* docs: mention what compilers fail
* fix: much simpler logic
* refactor: slightly faster / clearer
Adding missing `bytes` type to `test_constructors()`, to exercise the code change.
The changes in the PR were cherry-picked from PR #2409 (with a very minor
modification in test_pytypes.py related to flake8). Via PR #2409, these
changes were extensively tested in the Google environment, as summarized here:
https://docs.google.com/document/d/1TPL-J__mph_yHa1quDvsO12E_F5OZnvBaZlW9IIrz8M/
The changes in this PR did not cause an issues at all.
Note that `test_constructors()` before this PR passes for Python 2 only
because `pybind11::str` can hold `PyUnicodeObject` or `PyBytesObject`. As a
side-effect of this PR, `test_constructors()` no longer relies on this
permissive `pybind11::str` behavior. However, the permissive behavior is still
exercised/exposed via the existing `test_pybind11_str_raw_str()`.
The test code change is designed to enable easy removal later, when Python 2
support is dropped.
For completeness: confusingly, the non-test code changes travelled through PR
Example `ambiguous conversion` error fixed by this PR:
```
pybind11/tests/test_pytypes.cpp:214:23: error: ambiguous conversion for functional-style cast from 'pybind11::detail::item_accessor' (aka 'accessor<accessor_policies::generic_item>') to 'py::bytes'
"bytes"_a=py::bytes(d["bytes"]),
^~~~~~~~~~~~~~~~~~~~
pybind11/include/pybind11/detail/../pytypes.h:957:21: note: candidate constructor
PYBIND11_OBJECT(bytes, object, PYBIND11_BYTES_CHECK)
^
pybind11/include/pybind11/detail/../pytypes.h:957:21: note: candidate constructor
pybind11/include/pybind11/detail/../pytypes.h:987:15: note: candidate constructor
inline bytes::bytes(const pybind11::str &s) {
^
1 error generated.
```
To deal with exceptions that hit destructors or other noexcept functions.
Includes fixes to support Python 2.7 and extends documentation on
error handling.
@virtuald and @YannickJadoul both contributed to this PR.