You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
73 lines
3.0 KiB
73 lines
3.0 KiB
Limitations
|
|
###########
|
|
|
|
Design choices
|
|
^^^^^^^^^^^^^^
|
|
|
|
pybind11 strives to be a general solution to binding generation, but it also has
|
|
certain limitations:
|
|
|
|
- pybind11 casts away ``const``-ness in function arguments and return values.
|
|
This is in line with the Python language, which has no concept of ``const``
|
|
values. This means that some additional care is needed to avoid bugs that
|
|
would be caught by the type checker in a traditional C++ program.
|
|
|
|
- The NumPy interface ``pybind11::array`` greatly simplifies accessing
|
|
numerical data from C++ (and vice versa), but it's not a full-blown array
|
|
class like ``Eigen::Array`` or ``boost.multi_array``. ``Eigen`` objects are
|
|
directly supported, however, with ``pybind11/eigen.h``.
|
|
|
|
Large but useful features could be implemented in pybind11 but would lead to a
|
|
significant increase in complexity. Pybind11 strives to be simple and compact.
|
|
Users who require large new features are encouraged to write an extension to
|
|
pybind11; see `pybind11_json <https://github.com/pybind/pybind11_json>`_ for an
|
|
example.
|
|
|
|
|
|
Known bugs
|
|
^^^^^^^^^^
|
|
|
|
These are issues that hopefully will one day be fixed, but currently are
|
|
unsolved. If you know how to help with one of these issues, contributions
|
|
are welcome!
|
|
|
|
- Intel 20.2 is currently having an issue with the test suite.
|
|
`#2573 <https://github.com/pybind/pybind11/pull/2573>`_
|
|
|
|
- Debug mode Python does not support 1-5 tests in the test suite currently.
|
|
`#2422 <https://github.com/pybind/pybind11/pull/2422>`_
|
|
|
|
- PyPy3 7.3.1 and 7.3.2 have issues with several tests on 32-bit Windows.
|
|
|
|
Known limitations
|
|
^^^^^^^^^^^^^^^^^
|
|
|
|
These are issues that are probably solvable, but have not been fixed yet. A
|
|
clean, well written patch would likely be accepted to solve them.
|
|
|
|
- Type casters are not kept alive recursively.
|
|
`#2527 <https://github.com/pybind/pybind11/issues/2527>`_
|
|
One consequence is that containers of ``char *`` are currently not supported.
|
|
`#2245 <https://github.com/pybind/pybind11/issues/2245>`_
|
|
|
|
- The ``cpptest`` does not run on Windows with Python 3.8 or newer, due to DLL
|
|
loader changes. User code that is correctly installed should not be affected.
|
|
`#2560 <https://github.com/pybind/pybind11/issue/2560>`_
|
|
|
|
Python 3.9.0 warning
|
|
^^^^^^^^^^^^^^^^^^^^
|
|
|
|
Combining older versions of pybind11 (< 2.6.0) with Python on 3.9.0 will
|
|
trigger undefined behavior that typically manifests as crashes during
|
|
interpreter shutdown (but could also destroy your data. **You have been
|
|
warned**).
|
|
|
|
This issue has been
|
|
`fixed in Python <https://github.com/python/cpython/pull/22670>`_. As a
|
|
mitigation until 3.9.1 is released and commonly used, pybind11 (2.6.0 or newer)
|
|
includes a temporary workaround specifically when Python 3.9.0 is detected at
|
|
runtime, leaking about 50 bytes of memory when a callback function is garbage
|
|
collected. For reference; the pybind11 test suite has about 2,000 such
|
|
callbacks, but only 49 are garbage collected before the end-of-process. Wheels
|
|
built with Python 3.9.0 will correctly avoid the leak when run in Python 3.9.1.
|