1.. _changelog:
2
3Changelog
4#########
5
6Starting with version 1.8.0, pybind11 releases use a `semantic versioning
7<http://semver.org>`_ policy.
8
9v2.4.1 (Sep 20, 2019)
10-----------------------------------------------------
11
12* Fixed a problem involving implicit conversion from enumerations to integers
13  on Python 3.8. `1780 <https://github.com/pybind/pybind11/pull/1780>`_.
14
15v2.4.0 (Sep 19, 2019)
16-----------------------------------------------------
17
18* Try harder to keep pybind11-internal data structures separate when there
19  are potential ABI incompatibilities. Fixes crashes that occurred when loading
20  multiple pybind11 extensions that were e.g. compiled by GCC (libstdc++)
21  and Clang (libc++).
22  `#1588 <https://github.com/pybind/pybind11/pull/1588>`_ and
23  `c9f5a <https://github.com/pybind/pybind11/commit/c9f5a>`_.
24
25* Added support for ``__await__``, ``__aiter__``, and ``__anext__`` protocols.
26  `#1842 <https://github.com/pybind/pybind11/pull/1842>`_.
27
28* ``pybind11_add_module()``: don't strip symbols when compiling in
29  ``RelWithDebInfo`` mode. `#1980
30  <https://github.com/pybind/pybind11/pull/1980>`_.
31
32* ``enum_``: Reproduce Python behavior when comparing against invalid values
33  (e.g. ``None``, strings, etc.). Add back support for ``__invert__()``.
34  `#1912 <https://github.com/pybind/pybind11/pull/1912>`_,
35  `#1907 <https://github.com/pybind/pybind11/pull/1907>`_.
36
37* List insertion operation for ``py::list``.
38  Added ``.empty()`` to all collection types.
39  Added ``py::set::contains()`` and ``py::dict::contains()``.
40  `#1887 <https://github.com/pybind/pybind11/pull/1887>`_,
41  `#1884 <https://github.com/pybind/pybind11/pull/1884>`_,
42  `#1888 <https://github.com/pybind/pybind11/pull/1888>`_.
43
44* ``py::details::overload_cast_impl`` is available in C++11 mode, can be used
45  like ``overload_cast`` with an additional set of parantheses.
46  `#1581 <https://github.com/pybind/pybind11/pull/1581>`_.
47
48* Fixed ``get_include()`` on Conda.
49  `#1877 <https://github.com/pybind/pybind11/pull/1877>`_.
50
51* ``stl_bind.h``: negative indexing support.
52  `#1882 <https://github.com/pybind/pybind11/pull/1882>`_.
53
54* Minor CMake fix to add MinGW compatibility.
55  `#1851 <https://github.com/pybind/pybind11/pull/1851>`_.
56
57* GIL-related fixes.
58  `#1836 <https://github.com/pybind/pybind11/pull/1836>`_,
59  `8b90b <https://github.com/pybind/pybind11/commit/8b90b>`_.
60
61* Other very minor/subtle fixes and improvements.
62  `#1329 <https://github.com/pybind/pybind11/pull/1329>`_,
63  `#1910 <https://github.com/pybind/pybind11/pull/1910>`_,
64  `#1863 <https://github.com/pybind/pybind11/pull/1863>`_,
65  `#1847 <https://github.com/pybind/pybind11/pull/1847>`_,
66  `#1890 <https://github.com/pybind/pybind11/pull/1890>`_,
67  `#1860 <https://github.com/pybind/pybind11/pull/1860>`_,
68  `#1848 <https://github.com/pybind/pybind11/pull/1848>`_,
69  `#1821 <https://github.com/pybind/pybind11/pull/1821>`_,
70  `#1837 <https://github.com/pybind/pybind11/pull/1837>`_,
71  `#1833 <https://github.com/pybind/pybind11/pull/1833>`_,
72  `#1748 <https://github.com/pybind/pybind11/pull/1748>`_,
73  `#1852 <https://github.com/pybind/pybind11/pull/1852>`_.
74
75v2.3.0 (June 11, 2019)
76-----------------------------------------------------
77
78* Significantly reduced module binary size (10-20%) when compiled in C++11 mode
79  with GCC/Clang, or in any mode with MSVC. Function signatures are now always
80  precomputed at compile time (this was previously only available in C++14 mode
81  for non-MSVC compilers).
82  `#934 <https://github.com/pybind/pybind11/pull/934>`_.
83
84* Add basic support for tag-based static polymorphism, where classes
85  provide a method to returns the desired type of an instance.
86  `#1326 <https://github.com/pybind/pybind11/pull/1326>`_.
87
88* Python type wrappers (``py::handle``, ``py::object``, etc.)
89  now support map Python's number protocol onto C++ arithmetic
90  operators such as ``operator+``, ``operator/=``, etc.
91  `#1511 <https://github.com/pybind/pybind11/pull/1511>`_.
92
93* A number of improvements related to enumerations:
94
95   1. The ``enum_`` implementation was rewritten from scratch to reduce
96      code bloat. Rather than instantiating a full implementation for each
97      enumeration, most code is now contained in a generic base class.
98      `#1511 <https://github.com/pybind/pybind11/pull/1511>`_.
99
100   2. The ``value()``  method of ``py::enum_`` now accepts an optional
101      docstring that will be shown in the documentation of the associated
102      enumeration. `#1160 <https://github.com/pybind/pybind11/pull/1160>`_.
103
104   3. check for already existing enum value and throw an error if present.
105      `#1453 <https://github.com/pybind/pybind11/pull/1453>`_.
106
107* Support for over-aligned type allocation via C++17's aligned ``new``
108  statement. `#1582 <https://github.com/pybind/pybind11/pull/1582>`_.
109
110* Added ``py::ellipsis()`` method for slicing of multidimensional NumPy arrays
111  `#1502 <https://github.com/pybind/pybind11/pull/1502>`_.
112
113* Numerous Improvements to the ``mkdoc.py`` script for extracting documentation
114  from C++ header files.
115  `#1788 <https://github.com/pybind/pybind11/pull/1788>`_.
116
117* ``pybind11_add_module()``: allow including Python as a ``SYSTEM`` include path.
118  `#1416 <https://github.com/pybind/pybind11/pull/1416>`_.
119
120* ``pybind11/stl.h`` does not convert strings to ``vector<string>`` anymore.
121  `#1258 <https://github.com/pybind/pybind11/issues/1258>`_.
122
123* Mark static methods as such to fix auto-generated Sphinx documentation.
124  `#1732 <https://github.com/pybind/pybind11/pull/1732>`_.
125
126* Re-throw forced unwind exceptions (e.g. during pthread termination).
127  `#1208 <https://github.com/pybind/pybind11/pull/1208>`_.
128
129* Added ``__contains__`` method to the bindings of maps (``std::map``,
130  ``std::unordered_map``).
131  `#1767 <https://github.com/pybind/pybind11/pull/1767>`_.
132
133* Improvements to ``gil_scoped_acquire``.
134  `#1211 <https://github.com/pybind/pybind11/pull/1211>`_.
135
136* Type caster support for ``std::deque<T>``.
137  `#1609 <https://github.com/pybind/pybind11/pull/1609>`_.
138
139* Support for ``std::unique_ptr`` holders, whose deleters differ between a base and derived
140  class. `#1353 <https://github.com/pybind/pybind11/pull/1353>`_.
141
142* Construction of STL array/vector-like data structures from
143  iterators. Added an ``extend()`` operation.
144  `#1709 <https://github.com/pybind/pybind11/pull/1709>`_,
145
146* CMake build system improvements for projects that include non-C++
147  files (e.g. plain C, CUDA) in ``pybind11_add_module`` et al.
148  `#1678 <https://github.com/pybind/pybind11/pull/1678>`_.
149
150* Fixed asynchronous invocation and deallocation of Python functions
151  wrapped in ``std::function``.
152  `#1595 <https://github.com/pybind/pybind11/pull/1595>`_.
153
154* Fixes regarding return value policy propagation in STL type casters.
155  `#1603 <https://github.com/pybind/pybind11/pull/1603>`_.
156
157* Fixed scoped enum comparisons.
158  `#1571 <https://github.com/pybind/pybind11/pull/1571>`_.
159
160* Fixed iostream redirection for code that releases the GIL.
161  `#1368 <https://github.com/pybind/pybind11/pull/1368>`_,
162
163* A number of CI-related fixes.
164  `#1757 <https://github.com/pybind/pybind11/pull/1757>`_,
165  `#1744 <https://github.com/pybind/pybind11/pull/1744>`_,
166  `#1670 <https://github.com/pybind/pybind11/pull/1670>`_.
167
168v2.2.4 (September 11, 2018)
169-----------------------------------------------------
170
171* Use new Python 3.7 Thread Specific Storage (TSS) implementation if available.
172  `#1454 <https://github.com/pybind/pybind11/pull/1454>`_,
173  `#1517 <https://github.com/pybind/pybind11/pull/1517>`_.
174
175* Fixes for newer MSVC versions and C++17 mode.
176  `#1347 <https://github.com/pybind/pybind11/pull/1347>`_,
177  `#1462 <https://github.com/pybind/pybind11/pull/1462>`_.
178
179* Propagate return value policies to type-specific casters
180  when casting STL containers.
181  `#1455 <https://github.com/pybind/pybind11/pull/1455>`_.
182
183* Allow ostream-redirection of more than 1024 characters.
184  `#1479 <https://github.com/pybind/pybind11/pull/1479>`_.
185
186* Set ``Py_DEBUG`` define when compiling against a debug Python build.
187  `#1438 <https://github.com/pybind/pybind11/pull/1438>`_.
188
189* Untangle integer logic in number type caster to work for custom
190  types that may only be castable to a restricted set of builtin types.
191  `#1442 <https://github.com/pybind/pybind11/pull/1442>`_.
192
193* CMake build system: Remember Python version in cache file.
194  `#1434 <https://github.com/pybind/pybind11/pull/1434>`_.
195
196* Fix for custom smart pointers: use ``std::addressof`` to obtain holder
197  address instead of ``operator&``.
198  `#1435 <https://github.com/pybind/pybind11/pull/1435>`_.
199
200* Properly report exceptions thrown during module initialization.
201  `#1362 <https://github.com/pybind/pybind11/pull/1362>`_.
202
203* Fixed a segmentation fault when creating empty-shaped NumPy array.
204  `#1371 <https://github.com/pybind/pybind11/pull/1371>`_.
205
206* The version of Intel C++ compiler must be >= 2017, and this is now checked by
207  the header files. `#1363 <https://github.com/pybind/pybind11/pull/1363>`_.
208
209* A few minor typo fixes and improvements to the test suite, and
210  patches that silence compiler warnings.
211
212* Vectors now support construction from generators, as well as ``extend()`` from a
213  list or generator.
214  `#1496 <https://github.com/pybind/pybind11/pull/1496>`_.
215
216
217v2.2.3 (April 29, 2018)
218-----------------------------------------------------
219
220* The pybind11 header location detection was replaced by a new implementation
221  that no longer depends on ``pip`` internals (the recently released ``pip``
222  10 has restricted access to this API).
223  `#1190 <https://github.com/pybind/pybind11/pull/1190>`_.
224
225* Small adjustment to an implementation detail to work around a compiler segmentation fault in Clang 3.3/3.4.
226  `#1350 <https://github.com/pybind/pybind11/pull/1350>`_.
227
228* The minimal supported version of the Intel compiler was >= 17.0 since
229  pybind11 v2.1. This check is now explicit, and a compile-time error is raised
230  if the compiler meet the requirement.
231  `#1363 <https://github.com/pybind/pybind11/pull/1363>`_.
232
233* Fixed an endianness-related fault in the test suite.
234  `#1287 <https://github.com/pybind/pybind11/pull/1287>`_.
235
236v2.2.2 (February 7, 2018)
237-----------------------------------------------------
238
239* Fixed a segfault when combining embedded interpreter
240  shutdown/reinitialization with external loaded pybind11 modules.
241  `#1092 <https://github.com/pybind/pybind11/pull/1092>`_.
242
243* Eigen support: fixed a bug where Nx1/1xN numpy inputs couldn't be passed as
244  arguments to Eigen vectors (which for Eigen are simply compile-time fixed
245  Nx1/1xN matrices).
246  `#1106 <https://github.com/pybind/pybind11/pull/1106>`_.
247
248* Clarified to license by moving the licensing of contributions from
249  ``LICENSE`` into ``CONTRIBUTING.md``: the licensing of contributions is not
250  actually part of the software license as distributed.  This isn't meant to be
251  a substantial change in the licensing of the project, but addresses concerns
252  that the clause made the license non-standard.
253  `#1109 <https://github.com/pybind/pybind11/issues/1109>`_.
254
255* Fixed a regression introduced in 2.1 that broke binding functions with lvalue
256  character literal arguments.
257  `#1128 <https://github.com/pybind/pybind11/pull/1128>`_.
258
259* MSVC: fix for compilation failures under /permissive-, and added the flag to
260  the appveyor test suite.
261  `#1155 <https://github.com/pybind/pybind11/pull/1155>`_.
262
263* Fixed ``__qualname__`` generation, and in turn, fixes how class names
264  (especially nested class names) are shown in generated docstrings.
265  `#1171 <https://github.com/pybind/pybind11/pull/1171>`_.
266
267* Updated the FAQ with a suggested project citation reference.
268  `#1189 <https://github.com/pybind/pybind11/pull/1189>`_.
269
270* Added fixes for deprecation warnings when compiled under C++17 with
271  ``-Wdeprecated`` turned on, and add ``-Wdeprecated`` to the test suite
272  compilation flags.
273  `#1191 <https://github.com/pybind/pybind11/pull/1191>`_.
274
275* Fixed outdated PyPI URLs in ``setup.py``.
276  `#1213 <https://github.com/pybind/pybind11/pull/1213>`_.
277
278* Fixed a refcount leak for arguments that end up in a ``py::args`` argument
279  for functions with both fixed positional and ``py::args`` arguments.
280  `#1216 <https://github.com/pybind/pybind11/pull/1216>`_.
281
282* Fixed a potential segfault resulting from possible premature destruction of
283  ``py::args``/``py::kwargs`` arguments with overloaded functions.
284  `#1223 <https://github.com/pybind/pybind11/pull/1223>`_.
285
286* Fixed ``del map[item]`` for a ``stl_bind.h`` bound stl map.
287  `#1229 <https://github.com/pybind/pybind11/pull/1229>`_.
288
289* Fixed a regression from v2.1.x where the aggregate initialization could
290  unintentionally end up at a constructor taking a templated
291  ``std::initializer_list<T>`` argument.
292  `#1249 <https://github.com/pybind/pybind11/pull/1249>`_.
293
294* Fixed an issue where calling a function with a keep_alive policy on the same
295  nurse/patient pair would cause the internal patient storage to needlessly
296  grow (unboundedly, if the nurse is long-lived).
297  `#1251 <https://github.com/pybind/pybind11/issues/1251>`_.
298
299* Various other minor fixes.
300
301v2.2.1 (September 14, 2017)
302-----------------------------------------------------
303
304* Added ``py::module::reload()`` member function for reloading a module.
305  `#1040 <https://github.com/pybind/pybind11/pull/1040>`_.
306
307* Fixed a reference leak in the number converter.
308  `#1078 <https://github.com/pybind/pybind11/pull/1078>`_.
309
310* Fixed compilation with Clang on host GCC < 5 (old libstdc++ which isn't fully
311  C++11 compliant). `#1062 <https://github.com/pybind/pybind11/pull/1062>`_.
312
313* Fixed a regression where the automatic ``std::vector<bool>`` caster would
314  fail to compile. The same fix also applies to any container which returns
315  element proxies instead of references.
316  `#1053 <https://github.com/pybind/pybind11/pull/1053>`_.
317
318* Fixed a regression where the ``py::keep_alive`` policy could not be applied
319  to constructors. `#1065 <https://github.com/pybind/pybind11/pull/1065>`_.
320
321* Fixed a nullptr dereference when loading a ``py::module_local`` type
322  that's only registered in an external module.
323  `#1058 <https://github.com/pybind/pybind11/pull/1058>`_.
324
325* Fixed implicit conversion of accessors to types derived from ``py::object``.
326  `#1076 <https://github.com/pybind/pybind11/pull/1076>`_.
327
328* The ``name`` in ``PYBIND11_MODULE(name, variable)`` can now be a macro.
329  `#1082 <https://github.com/pybind/pybind11/pull/1082>`_.
330
331* Relaxed overly strict ``py::pickle()`` check for matching get and set types.
332  `#1064 <https://github.com/pybind/pybind11/pull/1064>`_.
333
334* Conversion errors now try to be more informative when it's likely that
335  a missing header is the cause (e.g. forgetting ``<pybind11/stl.h>``).
336  `#1077 <https://github.com/pybind/pybind11/pull/1077>`_.
337
338v2.2.0 (August 31, 2017)
339-----------------------------------------------------
340
341* Support for embedding the Python interpreter. See the
342  :doc:`documentation page </advanced/embedding>` for a
343  full overview of the new features.
344  `#774 <https://github.com/pybind/pybind11/pull/774>`_,
345  `#889 <https://github.com/pybind/pybind11/pull/889>`_,
346  `#892 <https://github.com/pybind/pybind11/pull/892>`_,
347  `#920 <https://github.com/pybind/pybind11/pull/920>`_.
348
349  .. code-block:: cpp
350
351      #include <pybind11/embed.h>
352      namespace py = pybind11;
353
354      int main() {
355          py::scoped_interpreter guard{}; // start the interpreter and keep it alive
356
357          py::print("Hello, World!"); // use the Python API
358      }
359
360* Support for inheriting from multiple C++ bases in Python.
361  `#693 <https://github.com/pybind/pybind11/pull/693>`_.
362
363  .. code-block:: python
364
365      from cpp_module import CppBase1, CppBase2
366
367      class PyDerived(CppBase1, CppBase2):
368          def __init__(self):
369              CppBase1.__init__(self)  # C++ bases must be initialized explicitly
370              CppBase2.__init__(self)
371
372* ``PYBIND11_MODULE`` is now the preferred way to create module entry points.
373  ``PYBIND11_PLUGIN`` is deprecated. See :ref:`macros` for details.
374  `#879 <https://github.com/pybind/pybind11/pull/879>`_.
375
376  .. code-block:: cpp
377
378      // new
379      PYBIND11_MODULE(example, m) {
380          m.def("add", [](int a, int b) { return a + b; });
381      }
382
383      // old
384      PYBIND11_PLUGIN(example) {
385          py::module m("example");
386          m.def("add", [](int a, int b) { return a + b; });
387          return m.ptr();
388      }
389
390* pybind11's headers and build system now more strictly enforce hidden symbol
391  visibility for extension modules. This should be seamless for most users,
392  but see the :doc:`upgrade` if you use a custom build system.
393  `#995 <https://github.com/pybind/pybind11/pull/995>`_.
394
395* Support for ``py::module_local`` types which allow multiple modules to
396  export the same C++ types without conflicts. This is useful for opaque
397  types like ``std::vector<int>``. ``py::bind_vector`` and ``py::bind_map``
398  now default to ``py::module_local`` if their elements are builtins or
399  local types. See :ref:`module_local` for details.
400  `#949 <https://github.com/pybind/pybind11/pull/949>`_,
401  `#981 <https://github.com/pybind/pybind11/pull/981>`_,
402  `#995 <https://github.com/pybind/pybind11/pull/995>`_,
403  `#997 <https://github.com/pybind/pybind11/pull/997>`_.
404
405* Custom constructors can now be added very easily using lambdas or factory
406  functions which return a class instance by value, pointer or holder. This
407  supersedes the old placement-new ``__init__`` technique.
408  See :ref:`custom_constructors` for details.
409  `#805 <https://github.com/pybind/pybind11/pull/805>`_,
410  `#1014 <https://github.com/pybind/pybind11/pull/1014>`_.
411
412  .. code-block:: cpp
413
414      struct Example {
415          Example(std::string);
416      };
417
418      py::class_<Example>(m, "Example")
419          .def(py::init<std::string>()) // existing constructor
420          .def(py::init([](int n) { // custom constructor
421              return std::make_unique<Example>(std::to_string(n));
422          }));
423
424* Similarly to custom constructors, pickling support functions are now bound
425  using the ``py::pickle()`` adaptor which improves type safety. See the
426  :doc:`upgrade` and :ref:`pickling` for details.
427  `#1038 <https://github.com/pybind/pybind11/pull/1038>`_.
428
429* Builtin support for converting C++17 standard library types and general
430  conversion improvements:
431
432  1. C++17 ``std::variant`` is supported right out of the box. C++11/14
433     equivalents (e.g. ``boost::variant``) can also be added with a simple
434     user-defined specialization. See :ref:`cpp17_container_casters` for details.
435     `#811 <https://github.com/pybind/pybind11/pull/811>`_,
436     `#845 <https://github.com/pybind/pybind11/pull/845>`_,
437     `#989 <https://github.com/pybind/pybind11/pull/989>`_.
438
439  2. Out-of-the-box support for C++17 ``std::string_view``.
440     `#906 <https://github.com/pybind/pybind11/pull/906>`_.
441
442  3. Improved compatibility of the builtin ``optional`` converter.
443     `#874 <https://github.com/pybind/pybind11/pull/874>`_.
444
445  4. The ``bool`` converter now accepts ``numpy.bool_`` and types which
446     define ``__bool__`` (Python 3.x) or ``__nonzero__`` (Python 2.7).
447     `#925 <https://github.com/pybind/pybind11/pull/925>`_.
448
449  5. C++-to-Python casters are now more efficient and move elements out
450     of rvalue containers whenever possible.
451     `#851 <https://github.com/pybind/pybind11/pull/851>`_,
452     `#936 <https://github.com/pybind/pybind11/pull/936>`_,
453     `#938 <https://github.com/pybind/pybind11/pull/938>`_.
454
455  6. Fixed ``bytes`` to ``std::string/char*`` conversion on Python 3.
456     `#817 <https://github.com/pybind/pybind11/pull/817>`_.
457
458  7. Fixed lifetime of temporary C++ objects created in Python-to-C++ conversions.
459     `#924 <https://github.com/pybind/pybind11/pull/924>`_.
460
461* Scope guard call policy for RAII types, e.g. ``py::call_guard<py::gil_scoped_release>()``,
462  ``py::call_guard<py::scoped_ostream_redirect>()``. See :ref:`call_policies` for details.
463  `#740 <https://github.com/pybind/pybind11/pull/740>`_.
464
465* Utility for redirecting C++ streams to Python (e.g. ``std::cout`` ->
466  ``sys.stdout``). Scope guard ``py::scoped_ostream_redirect`` in C++ and
467  a context manager in Python. See :ref:`ostream_redirect`.
468  `#1009 <https://github.com/pybind/pybind11/pull/1009>`_.
469
470* Improved handling of types and exceptions across module boundaries.
471  `#915 <https://github.com/pybind/pybind11/pull/915>`_,
472  `#951 <https://github.com/pybind/pybind11/pull/951>`_,
473  `#995 <https://github.com/pybind/pybind11/pull/995>`_.
474
475* Fixed destruction order of ``py::keep_alive`` nurse/patient objects
476  in reference cycles.
477  `#856 <https://github.com/pybind/pybind11/pull/856>`_.
478
479* Numpy and buffer protocol related improvements:
480
481  1. Support for negative strides in Python buffer objects/numpy arrays. This
482     required changing integers from unsigned to signed for the related C++ APIs.
483     Note: If you have compiler warnings enabled, you may notice some new conversion
484     warnings after upgrading. These can be resolved with ``static_cast``.
485     `#782 <https://github.com/pybind/pybind11/pull/782>`_.
486
487  2. Support ``std::complex`` and arrays inside ``PYBIND11_NUMPY_DTYPE``.
488     `#831 <https://github.com/pybind/pybind11/pull/831>`_,
489     `#832 <https://github.com/pybind/pybind11/pull/832>`_.
490
491  3. Support for constructing ``py::buffer_info`` and ``py::arrays`` using
492     arbitrary containers or iterators instead of requiring a ``std::vector``.
493     `#788 <https://github.com/pybind/pybind11/pull/788>`_,
494     `#822 <https://github.com/pybind/pybind11/pull/822>`_,
495     `#860 <https://github.com/pybind/pybind11/pull/860>`_.
496
497  4. Explicitly check numpy version and require >= 1.7.0.
498     `#819 <https://github.com/pybind/pybind11/pull/819>`_.
499
500* Support for allowing/prohibiting ``None`` for specific arguments and improved
501  ``None`` overload resolution order. See :ref:`none_arguments` for details.
502  `#843 <https://github.com/pybind/pybind11/pull/843>`_.
503  `#859 <https://github.com/pybind/pybind11/pull/859>`_.
504
505* Added ``py::exec()`` as a shortcut for ``py::eval<py::eval_statements>()``
506  and support for C++11 raw string literals as input. See :ref:`eval`.
507  `#766 <https://github.com/pybind/pybind11/pull/766>`_,
508  `#827 <https://github.com/pybind/pybind11/pull/827>`_.
509
510* ``py::vectorize()`` ignores non-vectorizable arguments and supports
511  member functions.
512  `#762 <https://github.com/pybind/pybind11/pull/762>`_.
513
514* Support for bound methods as callbacks (``pybind11/functional.h``).
515  `#815 <https://github.com/pybind/pybind11/pull/815>`_.
516
517* Allow aliasing pybind11 methods: ``cls.attr("foo") = cls.attr("bar")``.
518  `#802 <https://github.com/pybind/pybind11/pull/802>`_.
519
520* Don't allow mixed static/non-static overloads.
521  `#804 <https://github.com/pybind/pybind11/pull/804>`_.
522
523* Fixed overriding static properties in derived classes.
524  `#784 <https://github.com/pybind/pybind11/pull/784>`_.
525
526* Added support for write only properties.
527  `#1144 <https://github.com/pybind/pybind11/pull/1144>`_.
528
529* Improved deduction of member functions of a derived class when its bases
530  aren't registered with pybind11.
531  `#855 <https://github.com/pybind/pybind11/pull/855>`_.
532
533  .. code-block:: cpp
534
535      struct Base {
536          int foo() { return 42; }
537      }
538
539      struct Derived : Base {}
540
541      // Now works, but previously required also binding `Base`
542      py::class_<Derived>(m, "Derived")
543          .def("foo", &Derived::foo); // function is actually from `Base`
544
545* The implementation of ``py::init<>`` now uses C++11 brace initialization
546  syntax to construct instances, which permits binding implicit constructors of
547  aggregate types. `#1015 <https://github.com/pybind/pybind11/pull/1015>`_.
548
549    .. code-block:: cpp
550
551        struct Aggregate {
552            int a;
553            std::string b;
554        };
555
556        py::class_<Aggregate>(m, "Aggregate")
557            .def(py::init<int, const std::string &>());
558
559* Fixed issues with multiple inheritance with offset base/derived pointers.
560  `#812 <https://github.com/pybind/pybind11/pull/812>`_,
561  `#866 <https://github.com/pybind/pybind11/pull/866>`_,
562  `#960 <https://github.com/pybind/pybind11/pull/960>`_.
563
564* Fixed reference leak of type objects.
565  `#1030 <https://github.com/pybind/pybind11/pull/1030>`_.
566
567* Improved support for the ``/std:c++14`` and ``/std:c++latest`` modes
568  on MSVC 2017.
569  `#841 <https://github.com/pybind/pybind11/pull/841>`_,
570  `#999 <https://github.com/pybind/pybind11/pull/999>`_.
571
572* Fixed detection of private operator new on MSVC.
573  `#893 <https://github.com/pybind/pybind11/pull/893>`_,
574  `#918 <https://github.com/pybind/pybind11/pull/918>`_.
575
576* Intel C++ compiler compatibility fixes.
577  `#937 <https://github.com/pybind/pybind11/pull/937>`_.
578
579* Fixed implicit conversion of `py::enum_` to integer types on Python 2.7.
580  `#821 <https://github.com/pybind/pybind11/pull/821>`_.
581
582* Added ``py::hash`` to fetch the hash value of Python objects, and
583  ``.def(hash(py::self))`` to provide the C++ ``std::hash`` as the Python
584  ``__hash__`` method.
585  `#1034 <https://github.com/pybind/pybind11/pull/1034>`_.
586
587* Fixed ``__truediv__`` on Python 2 and ``__itruediv__`` on Python 3.
588  `#867 <https://github.com/pybind/pybind11/pull/867>`_.
589
590* ``py::capsule`` objects now support the ``name`` attribute. This is useful
591  for interfacing with ``scipy.LowLevelCallable``.
592  `#902 <https://github.com/pybind/pybind11/pull/902>`_.
593
594* Fixed ``py::make_iterator``'s ``__next__()`` for past-the-end calls.
595  `#897 <https://github.com/pybind/pybind11/pull/897>`_.
596
597* Added ``error_already_set::matches()`` for checking Python exceptions.
598  `#772 <https://github.com/pybind/pybind11/pull/772>`_.
599
600* Deprecated ``py::error_already_set::clear()``. It's no longer needed
601  following a simplification of the ``py::error_already_set`` class.
602  `#954 <https://github.com/pybind/pybind11/pull/954>`_.
603
604* Deprecated ``py::handle::operator==()`` in favor of ``py::handle::is()``
605  `#825 <https://github.com/pybind/pybind11/pull/825>`_.
606
607* Deprecated ``py::object::borrowed``/``py::object::stolen``.
608  Use ``py::object::borrowed_t{}``/``py::object::stolen_t{}`` instead.
609  `#771 <https://github.com/pybind/pybind11/pull/771>`_.
610
611* Changed internal data structure versioning to avoid conflicts between
612  modules compiled with different revisions of pybind11.
613  `#1012 <https://github.com/pybind/pybind11/pull/1012>`_.
614
615* Additional compile-time and run-time error checking and more informative messages.
616  `#786 <https://github.com/pybind/pybind11/pull/786>`_,
617  `#794 <https://github.com/pybind/pybind11/pull/794>`_,
618  `#803 <https://github.com/pybind/pybind11/pull/803>`_.
619
620* Various minor improvements and fixes.
621  `#764 <https://github.com/pybind/pybind11/pull/764>`_,
622  `#791 <https://github.com/pybind/pybind11/pull/791>`_,
623  `#795 <https://github.com/pybind/pybind11/pull/795>`_,
624  `#840 <https://github.com/pybind/pybind11/pull/840>`_,
625  `#844 <https://github.com/pybind/pybind11/pull/844>`_,
626  `#846 <https://github.com/pybind/pybind11/pull/846>`_,
627  `#849 <https://github.com/pybind/pybind11/pull/849>`_,
628  `#858 <https://github.com/pybind/pybind11/pull/858>`_,
629  `#862 <https://github.com/pybind/pybind11/pull/862>`_,
630  `#871 <https://github.com/pybind/pybind11/pull/871>`_,
631  `#872 <https://github.com/pybind/pybind11/pull/872>`_,
632  `#881 <https://github.com/pybind/pybind11/pull/881>`_,
633  `#888 <https://github.com/pybind/pybind11/pull/888>`_,
634  `#899 <https://github.com/pybind/pybind11/pull/899>`_,
635  `#928 <https://github.com/pybind/pybind11/pull/928>`_,
636  `#931 <https://github.com/pybind/pybind11/pull/931>`_,
637  `#944 <https://github.com/pybind/pybind11/pull/944>`_,
638  `#950 <https://github.com/pybind/pybind11/pull/950>`_,
639  `#952 <https://github.com/pybind/pybind11/pull/952>`_,
640  `#962 <https://github.com/pybind/pybind11/pull/962>`_,
641  `#965 <https://github.com/pybind/pybind11/pull/965>`_,
642  `#970 <https://github.com/pybind/pybind11/pull/970>`_,
643  `#978 <https://github.com/pybind/pybind11/pull/978>`_,
644  `#979 <https://github.com/pybind/pybind11/pull/979>`_,
645  `#986 <https://github.com/pybind/pybind11/pull/986>`_,
646  `#1020 <https://github.com/pybind/pybind11/pull/1020>`_,
647  `#1027 <https://github.com/pybind/pybind11/pull/1027>`_,
648  `#1037 <https://github.com/pybind/pybind11/pull/1037>`_.
649
650* Testing improvements.
651  `#798 <https://github.com/pybind/pybind11/pull/798>`_,
652  `#882 <https://github.com/pybind/pybind11/pull/882>`_,
653  `#898 <https://github.com/pybind/pybind11/pull/898>`_,
654  `#900 <https://github.com/pybind/pybind11/pull/900>`_,
655  `#921 <https://github.com/pybind/pybind11/pull/921>`_,
656  `#923 <https://github.com/pybind/pybind11/pull/923>`_,
657  `#963 <https://github.com/pybind/pybind11/pull/963>`_.
658
659v2.1.1 (April 7, 2017)
660-----------------------------------------------------
661
662* Fixed minimum version requirement for MSVC 2015u3
663  `#773 <https://github.com/pybind/pybind11/pull/773>`_.
664
665v2.1.0 (March 22, 2017)
666-----------------------------------------------------
667
668* pybind11 now performs function overload resolution in two phases. The first
669  phase only considers exact type matches, while the second allows for implicit
670  conversions to take place. A special ``noconvert()`` syntax can be used to
671  completely disable implicit conversions for specific arguments.
672  `#643 <https://github.com/pybind/pybind11/pull/643>`_,
673  `#634 <https://github.com/pybind/pybind11/pull/634>`_,
674  `#650 <https://github.com/pybind/pybind11/pull/650>`_.
675
676* Fixed a regression where static properties no longer worked with classes
677  using multiple inheritance. The ``py::metaclass`` attribute is no longer
678  necessary (and deprecated as of this release) when binding classes with
679  static properties.
680  `#679 <https://github.com/pybind/pybind11/pull/679>`_,
681
682* Classes bound using ``pybind11`` can now use custom metaclasses.
683  `#679 <https://github.com/pybind/pybind11/pull/679>`_,
684
685* ``py::args`` and ``py::kwargs`` can now be mixed with other positional
686  arguments when binding functions using pybind11.
687  `#611 <https://github.com/pybind/pybind11/pull/611>`_.
688
689* Improved support for C++11 unicode string and character types; added
690  extensive documentation regarding pybind11's string conversion behavior.
691  `#624 <https://github.com/pybind/pybind11/pull/624>`_,
692  `#636 <https://github.com/pybind/pybind11/pull/636>`_,
693  `#715 <https://github.com/pybind/pybind11/pull/715>`_.
694
695* pybind11 can now avoid expensive copies when converting Eigen arrays to NumPy
696  arrays (and vice versa). `#610 <https://github.com/pybind/pybind11/pull/610>`_.
697
698* The "fast path" in ``py::vectorize`` now works for any full-size group of C or
699  F-contiguous arrays. The non-fast path is also faster since it no longer performs
700  copies of the input arguments (except when type conversions are necessary).
701  `#610 <https://github.com/pybind/pybind11/pull/610>`_.
702
703* Added fast, unchecked access to NumPy arrays via a proxy object.
704  `#746 <https://github.com/pybind/pybind11/pull/746>`_.
705
706* Transparent support for class-specific ``operator new`` and
707  ``operator delete`` implementations.
708  `#755 <https://github.com/pybind/pybind11/pull/755>`_.
709
710* Slimmer and more efficient STL-compatible iterator interface for sequence types.
711  `#662 <https://github.com/pybind/pybind11/pull/662>`_.
712
713* Improved custom holder type support.
714  `#607 <https://github.com/pybind/pybind11/pull/607>`_.
715
716* ``nullptr`` to ``None`` conversion fixed in various builtin type casters.
717  `#732 <https://github.com/pybind/pybind11/pull/732>`_.
718
719* ``enum_`` now exposes its members via a special ``__members__`` attribute.
720  `#666 <https://github.com/pybind/pybind11/pull/666>`_.
721
722* ``std::vector`` bindings created using ``stl_bind.h`` can now optionally
723  implement the buffer protocol. `#488 <https://github.com/pybind/pybind11/pull/488>`_.
724
725* Automated C++ reference documentation using doxygen and breathe.
726  `#598 <https://github.com/pybind/pybind11/pull/598>`_.
727
728* Added minimum compiler version assertions.
729  `#727 <https://github.com/pybind/pybind11/pull/727>`_.
730
731* Improved compatibility with C++1z.
732  `#677 <https://github.com/pybind/pybind11/pull/677>`_.
733
734* Improved ``py::capsule`` API. Can be used to implement cleanup
735  callbacks that are involved at module destruction time.
736  `#752 <https://github.com/pybind/pybind11/pull/752>`_.
737
738* Various minor improvements and fixes.
739  `#595 <https://github.com/pybind/pybind11/pull/595>`_,
740  `#588 <https://github.com/pybind/pybind11/pull/588>`_,
741  `#589 <https://github.com/pybind/pybind11/pull/589>`_,
742  `#603 <https://github.com/pybind/pybind11/pull/603>`_,
743  `#619 <https://github.com/pybind/pybind11/pull/619>`_,
744  `#648 <https://github.com/pybind/pybind11/pull/648>`_,
745  `#695 <https://github.com/pybind/pybind11/pull/695>`_,
746  `#720 <https://github.com/pybind/pybind11/pull/720>`_,
747  `#723 <https://github.com/pybind/pybind11/pull/723>`_,
748  `#729 <https://github.com/pybind/pybind11/pull/729>`_,
749  `#724 <https://github.com/pybind/pybind11/pull/724>`_,
750  `#742 <https://github.com/pybind/pybind11/pull/742>`_,
751  `#753 <https://github.com/pybind/pybind11/pull/753>`_.
752
753v2.0.1 (Jan 4, 2017)
754-----------------------------------------------------
755
756* Fix pointer to reference error in type_caster on MSVC
757  `#583 <https://github.com/pybind/pybind11/pull/583>`_.
758
759* Fixed a segmentation in the test suite due to a typo
760  `cd7eac <https://github.com/pybind/pybind11/commit/cd7eac>`_.
761
762v2.0.0 (Jan 1, 2017)
763-----------------------------------------------------
764
765* Fixed a reference counting regression affecting types with custom metaclasses
766  (introduced in v2.0.0-rc1).
767  `#571 <https://github.com/pybind/pybind11/pull/571>`_.
768
769* Quenched a CMake policy warning.
770  `#570 <https://github.com/pybind/pybind11/pull/570>`_.
771
772v2.0.0-rc1 (Dec 23, 2016)
773-----------------------------------------------------
774
775The pybind11 developers are excited to issue a release candidate of pybind11
776with a subsequent v2.0.0 release planned in early January next year.
777
778An incredible amount of effort by went into pybind11 over the last ~5 months,
779leading to a release that is jam-packed with exciting new features and numerous
780usability improvements. The following list links PRs or individual commits
781whenever applicable.
782
783Happy Christmas!
784
785* Support for binding C++ class hierarchies that make use of multiple
786  inheritance. `#410 <https://github.com/pybind/pybind11/pull/410>`_.
787
788* PyPy support: pybind11 now supports nightly builds of PyPy and will
789  interoperate with the future 5.7 release. No code changes are necessary,
790  everything "just" works as usual. Note that we only target the Python 2.7
791  branch for now; support for 3.x will be added once its ``cpyext`` extension
792  support catches up. A few minor features remain unsupported for the time
793  being (notably dynamic attributes in custom types).
794  `#527 <https://github.com/pybind/pybind11/pull/527>`_.
795
796* Significant work on the documentation -- in particular, the monolithic
797  ``advanced.rst`` file was restructured into a easier to read hierarchical
798  organization. `#448 <https://github.com/pybind/pybind11/pull/448>`_.
799
800* Many NumPy-related improvements:
801
802  1. Object-oriented API to access and modify NumPy ``ndarray`` instances,
803     replicating much of the corresponding NumPy C API functionality.
804     `#402 <https://github.com/pybind/pybind11/pull/402>`_.
805
806  2. NumPy array ``dtype`` array descriptors are now first-class citizens and
807     are exposed via a new class ``py::dtype``.
808
809  3. Structured dtypes can be registered using the ``PYBIND11_NUMPY_DTYPE()``
810     macro. Special ``array`` constructors accepting dtype objects were also
811     added.
812
813     One potential caveat involving this change: format descriptor strings
814     should now be accessed via ``format_descriptor::format()`` (however, for
815     compatibility purposes, the old syntax ``format_descriptor::value`` will
816     still work for non-structured data types). `#308
817     <https://github.com/pybind/pybind11/pull/308>`_.
818
819  4. Further improvements to support structured dtypes throughout the system.
820     `#472 <https://github.com/pybind/pybind11/pull/472>`_,
821     `#474 <https://github.com/pybind/pybind11/pull/474>`_,
822     `#459 <https://github.com/pybind/pybind11/pull/459>`_,
823     `#453 <https://github.com/pybind/pybind11/pull/453>`_,
824     `#452 <https://github.com/pybind/pybind11/pull/452>`_, and
825     `#505 <https://github.com/pybind/pybind11/pull/505>`_.
826
827  5. Fast access operators. `#497 <https://github.com/pybind/pybind11/pull/497>`_.
828
829  6. Constructors for arrays whose storage is owned by another object.
830     `#440 <https://github.com/pybind/pybind11/pull/440>`_.
831
832  7. Added constructors for ``array`` and ``array_t`` explicitly accepting shape
833     and strides; if strides are not provided, they are deduced assuming
834     C-contiguity. Also added simplified constructors for 1-dimensional case.
835
836  8. Added buffer/NumPy support for ``char[N]`` and ``std::array<char, N>`` types.
837
838  9. Added ``memoryview`` wrapper type which is constructible from ``buffer_info``.
839
840* Eigen: many additional conversions and support for non-contiguous
841  arrays/slices.
842  `#427 <https://github.com/pybind/pybind11/pull/427>`_,
843  `#315 <https://github.com/pybind/pybind11/pull/315>`_,
844  `#316 <https://github.com/pybind/pybind11/pull/316>`_,
845  `#312 <https://github.com/pybind/pybind11/pull/312>`_, and
846  `#267 <https://github.com/pybind/pybind11/pull/267>`_
847
848* Incompatible changes in ``class_<...>::class_()``:
849
850    1. Declarations of types that provide access via the buffer protocol must
851       now include the ``py::buffer_protocol()`` annotation as an argument to
852       the ``class_`` constructor.
853
854    2. Declarations of types that require a custom metaclass (i.e. all classes
855       which include static properties via commands such as
856       ``def_readwrite_static()``) must now include the ``py::metaclass()``
857       annotation as an argument to the ``class_`` constructor.
858
859       These two changes were necessary to make type definitions in pybind11
860       future-proof, and to support PyPy via its cpyext mechanism. `#527
861       <https://github.com/pybind/pybind11/pull/527>`_.
862
863
864    3. This version of pybind11 uses a redesigned mechanism for instantiating
865       trampoline classes that are used to override virtual methods from within
866       Python. This led to the following user-visible syntax change: instead of
867
868       .. code-block:: cpp
869
870           py::class_<TrampolineClass>("MyClass")
871             .alias<MyClass>()
872             ....
873
874       write
875
876       .. code-block:: cpp
877
878           py::class_<MyClass, TrampolineClass>("MyClass")
879             ....
880
881       Importantly, both the original and the trampoline class are now
882       specified as an arguments (in arbitrary order) to the ``py::class_``
883       template, and the ``alias<..>()`` call is gone. The new scheme has zero
884       overhead in cases when Python doesn't override any functions of the
885       underlying C++ class. `rev. 86d825
886       <https://github.com/pybind/pybind11/commit/86d825>`_.
887
888* Added ``eval`` and ``eval_file`` functions for evaluating expressions and
889  statements from a string or file. `rev. 0d3fc3
890  <https://github.com/pybind/pybind11/commit/0d3fc3>`_.
891
892* pybind11 can now create types with a modifiable dictionary.
893  `#437 <https://github.com/pybind/pybind11/pull/437>`_ and
894  `#444 <https://github.com/pybind/pybind11/pull/444>`_.
895
896* Support for translation of arbitrary C++ exceptions to Python counterparts.
897  `#296 <https://github.com/pybind/pybind11/pull/296>`_ and
898  `#273 <https://github.com/pybind/pybind11/pull/273>`_.
899
900* Report full backtraces through mixed C++/Python code, better reporting for
901  import errors, fixed GIL management in exception processing.
902  `#537 <https://github.com/pybind/pybind11/pull/537>`_,
903  `#494 <https://github.com/pybind/pybind11/pull/494>`_,
904  `rev. e72d95 <https://github.com/pybind/pybind11/commit/e72d95>`_, and
905  `rev. 099d6e <https://github.com/pybind/pybind11/commit/099d6e>`_.
906
907* Support for bit-level operations, comparisons, and serialization of C++
908  enumerations. `#503 <https://github.com/pybind/pybind11/pull/503>`_,
909  `#508 <https://github.com/pybind/pybind11/pull/508>`_,
910  `#380 <https://github.com/pybind/pybind11/pull/380>`_,
911  `#309 <https://github.com/pybind/pybind11/pull/309>`_.
912  `#311 <https://github.com/pybind/pybind11/pull/311>`_.
913
914* The ``class_`` constructor now accepts its template arguments in any order.
915  `#385 <https://github.com/pybind/pybind11/pull/385>`_.
916
917* Attribute and item accessors now have a more complete interface which makes
918  it possible to chain attributes as in
919  ``obj.attr("a")[key].attr("b").attr("method")(1, 2, 3)``. `#425
920  <https://github.com/pybind/pybind11/pull/425>`_.
921
922* Major redesign of the default and conversion constructors in ``pytypes.h``.
923  `#464 <https://github.com/pybind/pybind11/pull/464>`_.
924
925* Added built-in support for ``std::shared_ptr`` holder type. It is no longer
926  necessary to to include a declaration of the form
927  ``PYBIND11_DECLARE_HOLDER_TYPE(T, std::shared_ptr<T>)`` (though continuing to
928  do so won't cause an error).
929  `#454 <https://github.com/pybind/pybind11/pull/454>`_.
930
931* New ``py::overload_cast`` casting operator to select among multiple possible
932  overloads of a function. An example:
933
934    .. code-block:: cpp
935
936        py::class_<Pet>(m, "Pet")
937            .def("set", py::overload_cast<int>(&Pet::set), "Set the pet's age")
938            .def("set", py::overload_cast<const std::string &>(&Pet::set), "Set the pet's name");
939
940  This feature only works on C++14-capable compilers.
941  `#541 <https://github.com/pybind/pybind11/pull/541>`_.
942
943* C++ types are automatically cast to Python types, e.g. when assigning
944  them as an attribute. For instance, the following is now legal:
945
946    .. code-block:: cpp
947
948        py::module m = /* ... */
949        m.attr("constant") = 123;
950
951  (Previously, a ``py::cast`` call was necessary to avoid a compilation error.)
952  `#551 <https://github.com/pybind/pybind11/pull/551>`_.
953
954* Redesigned ``pytest``-based test suite. `#321 <https://github.com/pybind/pybind11/pull/321>`_.
955
956* Instance tracking to detect reference leaks in test suite. `#324 <https://github.com/pybind/pybind11/pull/324>`_
957
958* pybind11 can now distinguish between multiple different instances that are
959  located at the same memory address, but which have different types.
960  `#329 <https://github.com/pybind/pybind11/pull/329>`_.
961
962* Improved logic in ``move`` return value policy.
963  `#510 <https://github.com/pybind/pybind11/pull/510>`_,
964  `#297 <https://github.com/pybind/pybind11/pull/297>`_.
965
966* Generalized unpacking API to permit calling Python functions from C++ using
967  notation such as ``foo(a1, a2, *args, "ka"_a=1, "kb"_a=2, **kwargs)``. `#372 <https://github.com/pybind/pybind11/pull/372>`_.
968
969* ``py::print()`` function whose behavior matches that of the native Python
970  ``print()`` function. `#372 <https://github.com/pybind/pybind11/pull/372>`_.
971
972* Added ``py::dict`` keyword constructor:``auto d = dict("number"_a=42,
973  "name"_a="World");``. `#372 <https://github.com/pybind/pybind11/pull/372>`_.
974
975* Added ``py::str::format()`` method and ``_s`` literal: ``py::str s = "1 + 2
976  = {}"_s.format(3);``. `#372 <https://github.com/pybind/pybind11/pull/372>`_.
977
978* Added ``py::repr()`` function which is equivalent to Python's builtin
979  ``repr()``. `#333 <https://github.com/pybind/pybind11/pull/333>`_.
980
981* Improved construction and destruction logic for holder types. It is now
982  possible to reference instances with smart pointer holder types without
983  constructing the holder if desired. The ``PYBIND11_DECLARE_HOLDER_TYPE``
984  macro now accepts an optional second parameter to indicate whether the holder
985  type uses intrusive reference counting.
986  `#533 <https://github.com/pybind/pybind11/pull/533>`_ and
987  `#561 <https://github.com/pybind/pybind11/pull/561>`_.
988
989* Mapping a stateless C++ function to Python and back is now "for free" (i.e.
990  no extra indirections or argument conversion overheads). `rev. 954b79
991  <https://github.com/pybind/pybind11/commit/954b79>`_.
992
993* Bindings for ``std::valarray<T>``.
994  `#545 <https://github.com/pybind/pybind11/pull/545>`_.
995
996* Improved support for C++17 capable compilers.
997  `#562 <https://github.com/pybind/pybind11/pull/562>`_.
998
999* Bindings for ``std::optional<t>``.
1000  `#475 <https://github.com/pybind/pybind11/pull/475>`_,
1001  `#476 <https://github.com/pybind/pybind11/pull/476>`_,
1002  `#479 <https://github.com/pybind/pybind11/pull/479>`_,
1003  `#499 <https://github.com/pybind/pybind11/pull/499>`_, and
1004  `#501 <https://github.com/pybind/pybind11/pull/501>`_.
1005
1006* ``stl_bind.h``: general improvements and support for ``std::map`` and
1007  ``std::unordered_map``.
1008  `#490 <https://github.com/pybind/pybind11/pull/490>`_,
1009  `#282 <https://github.com/pybind/pybind11/pull/282>`_,
1010  `#235 <https://github.com/pybind/pybind11/pull/235>`_.
1011
1012* The ``std::tuple``, ``std::pair``, ``std::list``, and ``std::vector`` type
1013  casters now accept any Python sequence type as input. `rev. 107285
1014  <https://github.com/pybind/pybind11/commit/107285>`_.
1015
1016* Improved CMake Python detection on multi-architecture Linux.
1017  `#532 <https://github.com/pybind/pybind11/pull/532>`_.
1018
1019* Infrastructure to selectively disable or enable parts of the automatically
1020  generated docstrings. `#486 <https://github.com/pybind/pybind11/pull/486>`_.
1021
1022* ``reference`` and ``reference_internal`` are now the default return value
1023  properties for static and non-static properties, respectively. `#473
1024  <https://github.com/pybind/pybind11/pull/473>`_. (the previous defaults
1025  were ``automatic``). `#473 <https://github.com/pybind/pybind11/pull/473>`_.
1026
1027* Support for ``std::unique_ptr`` with non-default deleters or no deleter at
1028  all (``py::nodelete``). `#384 <https://github.com/pybind/pybind11/pull/384>`_.
1029
1030* Deprecated ``handle::call()`` method. The new syntax to call Python
1031  functions is simply ``handle()``. It can also be invoked explicitly via
1032  ``handle::operator<X>()``, where ``X`` is an optional return value policy.
1033
1034* Print more informative error messages when ``make_tuple()`` or ``cast()``
1035  fail. `#262 <https://github.com/pybind/pybind11/pull/262>`_.
1036
1037* Creation of holder types for classes deriving from
1038  ``std::enable_shared_from_this<>`` now also works for ``const`` values.
1039  `#260 <https://github.com/pybind/pybind11/pull/260>`_.
1040
1041* ``make_iterator()`` improvements for better compatibility with various
1042  types (now uses prefix increment operator); it now also accepts iterators
1043  with different begin/end types as long as they are equality comparable.
1044  `#247 <https://github.com/pybind/pybind11/pull/247>`_.
1045
1046* ``arg()`` now accepts a wider range of argument types for default values.
1047  `#244 <https://github.com/pybind/pybind11/pull/244>`_.
1048
1049* Support ``keep_alive`` where the nurse object may be ``None``. `#341
1050  <https://github.com/pybind/pybind11/pull/341>`_.
1051
1052* Added constructors for ``str`` and ``bytes`` from zero-terminated char
1053  pointers, and from char pointers and length. Added constructors for ``str``
1054  from ``bytes`` and for ``bytes`` from ``str``, which will perform UTF-8
1055  decoding/encoding as required.
1056
1057* Many other improvements of library internals without user-visible changes
1058
1059
10601.8.1 (July 12, 2016)
1061----------------------
1062* Fixed a rare but potentially very severe issue when the garbage collector ran
1063  during pybind11 type creation.
1064
10651.8.0 (June 14, 2016)
1066----------------------
1067* Redesigned CMake build system which exports a convenient
1068  ``pybind11_add_module`` function to parent projects.
1069* ``std::vector<>`` type bindings analogous to Boost.Python's ``indexing_suite``
1070* Transparent conversion of sparse and dense Eigen matrices and vectors (``eigen.h``)
1071* Added an ``ExtraFlags`` template argument to the NumPy ``array_t<>`` wrapper
1072  to disable an enforced cast that may lose precision, e.g. to create overloads
1073  for different precisions and complex vs real-valued matrices.
1074* Prevent implicit conversion of floating point values to integral types in
1075  function arguments
1076* Fixed incorrect default return value policy for functions returning a shared
1077  pointer
1078* Don't allow registering a type via ``class_`` twice
1079* Don't allow casting a ``None`` value into a C++ lvalue reference
1080* Fixed a crash in ``enum_::operator==`` that was triggered by the ``help()`` command
1081* Improved detection of whether or not custom C++ types can be copy/move-constructed
1082* Extended ``str`` type to also work with ``bytes`` instances
1083* Added a ``"name"_a`` user defined string literal that is equivalent to ``py::arg("name")``.
1084* When specifying function arguments via ``py::arg``, the test that verifies
1085  the number of arguments now runs at compile time.
1086* Added ``[[noreturn]]`` attribute to ``pybind11_fail()`` to quench some
1087  compiler warnings
1088* List function arguments in exception text when the dispatch code cannot find
1089  a matching overload
1090* Added ``PYBIND11_OVERLOAD_NAME`` and ``PYBIND11_OVERLOAD_PURE_NAME`` macros which
1091  can be used to override virtual methods whose name differs in C++ and Python
1092  (e.g. ``__call__`` and ``operator()``)
1093* Various minor ``iterator`` and ``make_iterator()`` improvements
1094* Transparently support ``__bool__`` on Python 2.x and Python 3.x
1095* Fixed issue with destructor of unpickled object not being called
1096* Minor CMake build system improvements on Windows
1097* New ``pybind11::args`` and ``pybind11::kwargs`` types to create functions which
1098  take an arbitrary number of arguments and keyword arguments
1099* New syntax to call a Python function from C++ using ``*args`` and ``*kwargs``
1100* The functions ``def_property_*`` now correctly process docstring arguments (these
1101  formerly caused a segmentation fault)
1102* Many ``mkdoc.py`` improvements (enumerations, template arguments, ``DOC()``
1103  macro accepts more arguments)
1104* Cygwin support
1105* Documentation improvements (pickling support, ``keep_alive``, macro usage)
1106
11071.7 (April 30, 2016)
1108----------------------
1109* Added a new ``move`` return value policy that triggers C++11 move semantics.
1110  The automatic return value policy falls back to this case whenever a rvalue
1111  reference is encountered
1112* Significantly more general GIL state routines that are used instead of
1113  Python's troublesome ``PyGILState_Ensure`` and ``PyGILState_Release`` API
1114* Redesign of opaque types that drastically simplifies their usage
1115* Extended ability to pass values of type ``[const] void *``
1116* ``keep_alive`` fix: don't fail when there is no patient
1117* ``functional.h``: acquire the GIL before calling a Python function
1118* Added Python RAII type wrappers ``none`` and ``iterable``
1119* Added ``*args`` and ``*kwargs`` pass-through parameters to
1120  ``pybind11.get_include()`` function
1121* Iterator improvements and fixes
1122* Documentation on return value policies and opaque types improved
1123
11241.6 (April 30, 2016)
1125----------------------
1126* Skipped due to upload to PyPI gone wrong and inability to recover
1127  (https://github.com/pypa/packaging-problems/issues/74)
1128
11291.5 (April 21, 2016)
1130----------------------
1131* For polymorphic types, use RTTI to try to return the closest type registered with pybind11
1132* Pickling support for serializing and unserializing C++ instances to a byte stream in Python
1133* Added a convenience routine ``make_iterator()`` which turns a range indicated
1134  by a pair of C++ iterators into a iterable Python object
1135* Added ``len()`` and a variadic ``make_tuple()`` function
1136* Addressed a rare issue that could confuse the current virtual function
1137  dispatcher and another that could lead to crashes in multi-threaded
1138  applications
1139* Added a ``get_include()`` function to the Python module that returns the path
1140  of the directory containing the installed pybind11 header files
1141* Documentation improvements: import issues, symbol visibility, pickling, limitations
1142* Added casting support for ``std::reference_wrapper<>``
1143
11441.4 (April 7, 2016)
1145--------------------------
1146* Transparent type conversion for ``std::wstring`` and ``wchar_t``
1147* Allow passing ``nullptr``-valued strings
1148* Transparent passing of ``void *`` pointers using capsules
1149* Transparent support for returning values wrapped in ``std::unique_ptr<>``
1150* Improved docstring generation for compatibility with Sphinx
1151* Nicer debug error message when default parameter construction fails
1152* Support for "opaque" types that bypass the transparent conversion layer for STL containers
1153* Redesigned type casting interface to avoid ambiguities that could occasionally cause compiler errors
1154* Redesigned property implementation; fixes crashes due to an unfortunate default return value policy
1155* Anaconda package generation support
1156
11571.3 (March 8, 2016)
1158--------------------------
1159
1160* Added support for the Intel C++ compiler (v15+)
1161* Added support for the STL unordered set/map data structures
1162* Added support for the STL linked list data structure
1163* NumPy-style broadcasting support in ``pybind11::vectorize``
1164* pybind11 now displays more verbose error messages when ``arg::operator=()`` fails
1165* pybind11 internal data structures now live in a version-dependent namespace to avoid ABI issues
1166* Many, many bugfixes involving corner cases and advanced usage
1167
11681.2 (February 7, 2016)
1169--------------------------
1170
1171* Optional: efficient generation of function signatures at compile time using C++14
1172* Switched to a simpler and more general way of dealing with function default
1173  arguments. Unused keyword arguments in function calls are now detected and
1174  cause errors as expected
1175* New ``keep_alive`` call policy analogous to Boost.Python's ``with_custodian_and_ward``
1176* New ``pybind11::base<>`` attribute to indicate a subclass relationship
1177* Improved interface for RAII type wrappers in ``pytypes.h``
1178* Use RAII type wrappers consistently within pybind11 itself. This
1179  fixes various potential refcount leaks when exceptions occur
1180* Added new ``bytes`` RAII type wrapper (maps to ``string`` in Python 2.7)
1181* Made handle and related RAII classes const correct, using them more
1182  consistently everywhere now
1183* Got rid of the ugly ``__pybind11__`` attributes on the Python side---they are
1184  now stored in a C++ hash table that is not visible in Python
1185* Fixed refcount leaks involving NumPy arrays and bound functions
1186* Vastly improved handling of shared/smart pointers
1187* Removed an unnecessary copy operation in ``pybind11::vectorize``
1188* Fixed naming clashes when both pybind11 and NumPy headers are included
1189* Added conversions for additional exception types
1190* Documentation improvements (using multiple extension modules, smart pointers,
1191  other minor clarifications)
1192* unified infrastructure for parsing variadic arguments in ``class_`` and cpp_function
1193* Fixed license text (was: ZLIB, should have been: 3-clause BSD)
1194* Python 3.2 compatibility
1195* Fixed remaining issues when accessing types in another plugin module
1196* Added enum comparison and casting methods
1197* Improved SFINAE-based detection of whether types are copy-constructible
1198* Eliminated many warnings about unused variables and the use of ``offsetof()``
1199* Support for ``std::array<>`` conversions
1200
12011.1 (December 7, 2015)
1202--------------------------
1203
1204* Documentation improvements (GIL, wrapping functions, casting, fixed many typos)
1205* Generalized conversion of integer types
1206* Improved support for casting function objects
1207* Improved support for ``std::shared_ptr<>`` conversions
1208* Initial support for ``std::set<>`` conversions
1209* Fixed type resolution issue for types defined in a separate plugin module
1210* Cmake build system improvements
1211* Factored out generic functionality to non-templated code (smaller code size)
1212* Added a code size / compile time benchmark vs Boost.Python
1213* Added an appveyor CI script
1214
12151.0 (October 15, 2015)
1216------------------------
1217* Initial release
1218