Commit Graph

59 Commits

Author SHA1 Message Date
Ralf W. Grosse-Kunstleve
d958b789af Merge branch 'master' into sh_merge_master 2024-06-21 22:55:00 -07:00
Ralf W. Grosse-Kunstleve
f1a2e03d19
feat: remove Python 3.6 support (#5177)
* Change Python version guard: PYTHON < 3.7 IS UNSUPPORTED.

* Replace or remove Python 3.6 jobs.

* Move appveyor to Python 3.8

* Change `[tool.pylint]` `master.py-version` from `3.6` to `3.8`

* Change `[tool.pylint]` `master.py-version` to `3.7`

* Remove `centos:7` job; Change almalinux:8 job to use Python 3.8

* Try 🐍 3.8 • ubuntu-20.04 • x64 without `-DCMAKE_CXX_FLAGS="-D_=1"`

* Update setup.cfg as suggested by @henryiii

* Try running `cmake --build . --target cpptest` on all platforms (`standard` job).

* Disable deadsnakes jobs entirely.

* Apply PR #5179: Add Python 3.10, 3.11, 3.12 to win32 job matrix.

* Add back `-DCMAKE_CXX_FLAGS="-D_=1"` but do not install boost in that case.

* PY_VERSION_HEX < 3.7 cleanup pass: include/pybind11

* WITH_THREAD cleanup pass: include/pybind11

* Undo incorrect change.

* Revert "Disable deadsnakes jobs entirely."

This reverts commit bbcd0087b2.

* WITH_THREAD cleanup pass: tests/

* Change Python version guard in pybind11/__init__.py: pybind11 does not support Python < 3.7.

* Misc cleanup pass

* chore: use future imports

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>

* Update tests/test_numpy_array.py

* Update test_numpy_array.py

---------

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>
Co-authored-by: Henry Schreiner <henryschreineriii@gmail.com>
2024-06-22 00:55:00 -04:00
Ralf W. Grosse-Kunstleve
124b62a087 Merge branch 'master' into sh_merge_master 2023-11-07 23:44:24 -08:00
Henry Schreiner
c758b81f3b
chore: move to ruff-format (#4912)
Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>
Co-authored-by: Ralf W. Grosse-Kunstleve <rwgk@google.com>
2023-11-07 23:42:54 -08:00
Ralf W. Grosse-Kunstleve
eb456b1599 Merge branch 'master' into sh_merge_master 2023-05-08 10:27:38 -07:00
Ralf W. Grosse-Kunstleve
e9b961d9b9
Elide to-python conversion of setter return values (#4621)
* Reproducer for property setter with return type that is not wrapped.

* Use `py::class_<OptionsBase>()` to work around the return value conversion issue.

* WIP drop_return_value

* Remove struct drop_return_value

* Introduce `return_value_policy::return_none` for use by setters.

* Add `is_setter` to attr.h and use from `.def_property()`

* Merge the new test into test_methods_and_attributes

* Remove return_none return_value_policy again.

* Fix oversight (NOLINTNEXTLINE placement).

* Simplification (for the better) found while searching for a way to resolve GCC build failures.

Example of failure resolved by this change:

g++ (Ubuntu 9.4.0-1ubuntu1~20.04.1) 9.4.0

```
cd /build/tests && /usr/bin/c++ -DPYBIND11_TEST_EIGEN -Dpybind11_tests_EXPORTS -I/mounted_pybind11/include -isystem /usr/include/python3.8 -isystem /build/_deps/eigen-src -g -std=c++17 -fPIC -fvisibility=hidden -Wall -Wextra -Wconversion -Wcast-qual -Wdeprecated -Wundef -Wnon-virtual-dtor -MD -MT tests/CMakeFiles/pybind11_tests.dir/test_buffers.cpp.o -MF CMakeFiles/pybind11_tests.dir/test_buffers.cpp.o.d -o CMakeFiles/pybind11_tests.dir/test_buffers.cpp.o -c /mounted_pybind11/tests/test_buffers.cpp
In file included from /mounted_pybind11/include/pybind11/stl.h:12,
                 from /mounted_pybind11/tests/test_buffers.cpp:10:
/mounted_pybind11/include/pybind11/pybind11.h: In instantiation of ‘pybind11::class_<type_, options>& pybind11::class_<type_, options>::def_property(const char*, const Getter&, const Setter&, const Extra& ...) [with Getter = pybind11::cpp_function; Setter = std::nullptr_t; Extra = {pybind11::return_value_policy}; type_ = pybind11::buffer_info; options = {}]’:
/mounted_pybind11/include/pybind11/pybind11.h:1716:58:   required from ‘pybind11::class_<type_, options>& pybind11::class_<type_, options>::def_property_readonly(const char*, const pybind11::cpp_function&, const Extra& ...) [with Extra = {pybind11::return_value_policy}; type_ = pybind11::buffer_info; options = {}]’
/mounted_pybind11/include/pybind11/pybind11.h:1684:9:   required from ‘pybind11::class_<type_, options>& pybind11::class_<type_, options>::def_readonly(const char*, const D C::*, const Extra& ...) [with C = pybind11::buffer_info; D = long int; Extra = {}; type_ = pybind11::buffer_info; options = {}]’
/mounted_pybind11/tests/test_buffers.cpp:209:61:   required from here
/mounted_pybind11/include/pybind11/pybind11.h:1740:25: error: call of overloaded ‘cpp_function(std::nullptr_t&, pybind11::is_setter)’ is ambiguous
 1740 |             name, fget, cpp_function(method_adaptor<type>(fset), is_setter()), extra...);
      |                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/mounted_pybind11/include/pybind11/pybind11.h:101:5: note: candidate: ‘pybind11::cpp_function::cpp_function(Func&&, const Extra& ...) [with Func = std::nullptr_t&; Extra = {pybind11::is_setter}; <template-parameter-1-3> = void]’
  101 |     cpp_function(Func &&f, const Extra &...extra) {
      |     ^~~~~~~~~~~~
In file included from /mounted_pybind11/include/pybind11/stl.h:12,
                 from /mounted_pybind11/tests/test_buffers.cpp:10:
/mounted_pybind11/include/pybind11/pybind11.h:87:5: note: candidate: ‘pybind11::cpp_function::cpp_function(std::nullptr_t, const Extra& ...) [with Extra = {pybind11::is_setter}; std::nullptr_t = std::nullptr_t]’
   87 |     cpp_function(std::nullptr_t, const Extra &...) {}
      |     ^~~~~~~~~~~~
```

* Bug fix: obvious in hindsight. I thought the original version was incrementing the reference count for None, but no.

Discovered via many failing tests in the wild (10s of thousands).

It is very tricky to construct a meaningful unit test for this bug specifically. It's unlikely to come back, because 10s of thousands of tests will fail again.
2023-05-08 10:13:54 -07:00
Ralf W. Grosse-Kunstleve
9005b55bdf Merge branch 'master' into sh_merge_master 2023-02-22 12:32:31 -08:00
Henry Schreiner
438034c5b8
chore: move to Ruff and add rules (#4483) 2023-02-22 06:18:55 -08:00
Ralf W. Grosse-Kunstleve
27ce64fc43 Merge branch 'master' into sh_merge_master 2022-07-09 21:47:49 -07:00
Aaron Gokaslan
2af163d9c7
Fix: 3.11 beta support (#3923)
* Placeholder commit for 3.11 testing

* Does this fix it?

* Try suggestion

* Placeholder commit for 3.11 testing

* Does this fix it?

* Try suggestion

* fix: try using modern init for embedded interp

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>

* fix: error message changed in 3.11

* fix: apply logic in Python manually

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>

* fix autodetect dynamic attrs in 3.11

* fix: include error message if possible in error

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>

* ci: enable standard Python 3.11 testing

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>

* Make dynamic attrs condtiion exclusive to ver.

Co-authored-by: Henry Schreiner <henryschreineriii@gmail.com>
2022-07-06 16:35:12 -04:00
Ralf W. Grosse-Kunstleve
2ee1e6445d Merge branch 'master' into sh_merge_master 2022-05-02 12:41:48 -07:00
Michael Voznesensky
f0b9f755e4
Replace error printing code gated by NDEBUG with a new flag: PYBIND11_DETAILED_ERROR_MESSAGES (#3913)
* Update cast.h

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* Move definition to detail/common, change name, apply everywhere

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* Rename debug_enabled in tests to detailed_error_messages_enabled
2022-05-02 15:30:19 -04:00
Ralf W. Grosse-Kunstleve
e1751c04f0 Merge branch 'master' into sh_merge_master_after_clang-format_etc
First pass manually resolving the many merge conflicts.
2022-02-14 14:36:08 -08:00
Ralf W. Grosse-Kunstleve
6493f496e3
Python 2 removal part 1: tests (C++ code is intentionally ~untouched) (#3688)
* `#error BYE_BYE_GOLDEN_SNAKE`

* Removing everything related to 2.7 from ci.yml

* Commenting-out Centos7

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

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

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

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

* Removing obsolete Python 2 mention in compiling.rst

* Proper `#error` for Python 2.

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

* chore: bump pre-commit

* style: run pre-commit for pyupgrade 3+

* tests: use sys.version_info, not PY

* chore: more Python 2 removal

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

* Update pre-commit hooks

* Fix pre-commit hook

* refactor: remove Python 2 from CMake

* refactor: remove Python 2 from setup code

* refactor: simplify, better static typing

* feat: fail with nice messages

* refactor: drop Python 2 C++ code

* docs: cleanup for Python 3

* revert: intree

revert: intree

* docs: minor touchup to py2 statement

Co-authored-by: Henry Schreiner <henryschreineriii@gmail.com>
Co-authored-by: Aaron Gokaslan <skylion.aaron@gmail.com>
2022-02-10 18:28:08 -08:00
Ralf W. Grosse-Kunstleve
58c7f076bc Merge branch 'master' into sh_merge_master 2021-11-07 16:26:55 -08:00
Boris Rasin
01f938e799
fix: add missing std::forward calls (#3443)
* fix: add missing std::forward calls

Two of the four cpp_function overloads are missing std::forward calls, which seems like a simple oversight.

* add test for https://github.com/pybind/pybind11/pull/3443

* add py tests

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* fix test

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
2021-11-07 18:35:25 -05:00
Ralf W. Grosse-Kunstleve
fd68dede10 Merge branch 'master' into sh_merge_master 2021-10-11 13:18:33 -07:00
Aaron Gokaslan
f4c81e0877
maint: Add additional linter-related pre-commit hooks (#3337)
* Add additional pygrep pre-commit hooks

* Remove useless noqas with hook

* Fix all single rst backticks

* Simplify mypy pre-commit hook with upstream fixes

* Add back missing comment

* Add one last pygrep hook
2021-10-08 08:38:04 -04:00
Ralf W. Grosse-Kunstleve
8865d28317 Automatic part of merging branch 'master' into sh_merge_master.
The only manual intervention was to remove the merge conflict markers in pybind11.h.

TODO in separate commit: complete removal of the obsolete detail/pragma_warning_block.h.
2021-08-14 07:54:40 -07:00
Aaron Gokaslan
9df2f1ff13
maint(precommit): Apply isort (#3195)
* Apply isort

* Tweak isort config

* Add env.py as a known_first_party

* Add one missing known first party

* Make config compat with older isort versions

* Add another comment

* Revert pyproject setting
2021-08-13 12:37:05 -04:00
Ralf W. Grosse-Kunstleve
cad79c1146
tests: remove very minor oversight in PR #3059. (#3066) 2021-06-30 17:30:26 -04:00
Ralf W. Grosse-Kunstleve
94f0db58ee Fixing merge accident related to merging PR #3059 from master.
I did not go back to check when and why exactly this slipped in.

Also removing unused `msg` (oversight in PR #3059).
2021-06-30 13:30:34 -07:00
Ralf W. Grosse-Kunstleve
c2111fd353 Merge branch 'master' into smart_holder 2021-06-30 12:36:27 -07:00
Cris Luengo
57a36633c4 fix: enable py::implicitly_convertible<py::none, ...> for py::class_-wrapped types (#3059)
* Allow casting from None to a custom object, closes #2778

* ci.yml patch from the smart_holder branch for full CI coverage.
2021-06-25 21:57:45 -07:00
Cris Luengo
93e69191c1
fix: enable py::implicitly_convertible<py::none, ...> for py::class_-wrapped types (#3059)
* Allow casting from None to a custom object, closes #2778

* ci.yml patch from the smart_holder branch for full CI coverage.
2021-06-25 17:56:17 -07:00
Ralf W. Grosse-Kunstleve
99de498b26
Bug fix: adding back !is_alias<Class>(ptr) that were accidentally omitted. (#2958)
* Bug fix: adding back `!is_alias<Class>(ptr)` that were accidentally omitted.

* Introducing PYBIND11_SH_AVL, PYBIND11_SH_DEF macros. Applying PYBIND11_SH_DEF to test_factory_constructors.py to complete test coverage.

* Using PYBIND11_SH_DEF in test_methods_and_attributes.cpp, for more complete test coverage.

* Using PYBIND11_SH_DEF in test_multiple_inheritance.cpp, for more complete test coverage.

* Cleaning up test_classh_mock.cpp.

* Better explanations for PYBIND11_SH_AVL, PYBIND11_SH_DEF.

* Disabling 3.10-dev builds.
2021-04-19 10:54:37 -07:00
Boris Staletic
06b673a0da
Allow NULL value in pybind11_meta_setattro (#2629) 2020-11-05 23:54:37 +01:00
Mana Borwornpadungkitti
6edd0e6d90
fix: Reject keyword argument None with .none(false) (#2611)
* 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>
2020-10-20 23:57:22 +02:00
Henry Schreiner
c50f90eca6
style: use Black everywhere (#2594)
* style: use Black everywhere

* style: minor touchup from review
2020-10-16 16:38:13 -04:00
Henry Schreiner
9a0c96dd4c
feat: py::prepend tag (#1131)
* feat: add a priority overload with py::prepend

* doc: fix wording as suggested by rwgk

* feat: add get_pointer

* refactor: is_prepended -> prepend (internal)

* docs: suggestion from @wjakob

* tests: add test covering get_pointer/set_pointer
2020-10-05 22:36:33 -04:00
Henry Schreiner
4d9024ec71
tests: cleanup and ci hardening (#2397)
* tests: refactor and cleanup

* refactor: more consistent

* tests: vendor six

* tests: more xfails, nicer system

* tests: simplify to info

* tests: suggestions from @YannickJadoul and @bstaletic

* tests: restore some pypy tests that now pass

* tests: rename info to env

* tests: strict False/True

* tests: drop explicit strict=True again

* tests: reduce minimum PyTest to 3.1
2020-08-16 16:02:12 -04:00
Henry Schreiner
d8c7ee00a6
ci: GHA basic format & pre-commit (#2309) 2020-07-20 13:35:21 -04:00
Robert Haschke
f2226aefe0
Allow perfect forwarding of method args (#2048) 2020-07-07 15:56:07 +02:00
B Krishna Chaitanya
714424387f Refactor: Extract Custom Type Casts related tests 2020-07-01 00:07:49 +02:00
Clemens Sielaff
63df87fa49
Add lvalue ref-qualified cpp_function constructors (#2213)
* added overload for l-value ref-qualified methods

* Added test.
Before, the code would have failed to build.
2020-06-10 13:35:10 +02:00
Wenzel Jakob
9fd4712121 fix test suite (pytest changes in ExceptionInfo class) 2019-07-06 17:35:31 +02:00
Ted Drain
0a0758ce3a Added write only property functions for issue #1142 (#1144)
py::class_<T>'s `def_property` and `def_property_static` can now take a
`nullptr` as the getter to allow a write-only property to be established
(mirroring Python's `property()` built-in when `None` is given for the
getter).

This also updates properties to use the new nullptr constructor internally.
2017-11-07 12:35:27 -04:00
Jason Rhinelander
391c75447d Update all remaining tests to new test styles
This udpates all the remaining tests to the new test suite code and
comment styles started in #898.  For the most part, the test coverage
here is unchanged, with a few minor exceptions as noted below.

- test_constants_and_functions: this adds more overload tests with
  overloads with different number of arguments for more comprehensive
  overload_cast testing.  The test style conversion broke the overload
  tests under MSVC 2015, prompting the additional tests while looking
  for a workaround.

- test_eigen: this dropped the unused functions `get_cm_corners` and
  `get_cm_corners_const`--these same tests were duplicates of the same
  things provided (and used) via ReturnTester methods.

- test_opaque_types: this test had a hidden dependence on ExampleMandA
  which is now fixed by using the global UserType which suffices for the
  relevant test.

- test_methods_and_attributes: this required some additions to UserType
  to make it usable as a replacement for the test's previous SimpleType:
  UserType gained a value mutator, and the `value` property is not
  mutable (it was previously readonly).  Some overload tests were also
  added to better test overload_cast (as described above).

- test_numpy_array: removed the untemplated mutate_data/mutate_data_t:
  the templated versions with an empty parameter pack expand to the same
  thing.

- test_stl: this was already mostly in the new style; this just tweaks
  things a bit, localizing a class, and adding some missing
  `// test_whatever` comments.

- test_virtual_functions: like `test_stl`, this was mostly in the new
  test style already, but needed some `// test_whatever` comments.
  This commit also moves the inherited virtual example code to the end
  of the file, after the main set of tests (since it is less important
  than the other tests, and rather length); it also got renamed to
  `test_inherited_virtuals` (from `test_inheriting_repeat`) because it
  tests both inherited virtual approaches, not just the repeat approach.
2017-08-05 18:46:22 -04:00
Jason Rhinelander
60526d4636 Support take_ownership for custom type casters given a pointer
This changes the pointer `cast()` in `PYBIND11_TYPE_CASTER` to recognize
the `take_ownership` policy: if casting a pointer with take-ownership,
the `cast()` now recalls `cast()` with a dereferenced rvalue (rather
than the previous code, which was always calling it with a const lvalue
reference), and deletes the pointer after the chained `cast()` is
complete.

This makes code like:

    m.def("f", []() { return new std::vector<int>(100, 1); },
        py::return_value_policy::take_ownership);

do the expected thing by taking over ownership of the returned pointer
(which is deleted once the chained cast completes).
2017-07-16 11:04:43 -04:00
Jason Rhinelander
23bf894590 Override deduced Base class when defining Derived methods
When defining method from a member function pointer (e.g. `.def("f",
&Derived::f)`) we run into a problem if `&Derived::f` is actually
implemented in some base class `Base` when `Base` isn't
pybind-registered.

This happens because the class type is deduced from the member function
pointer, which then becomes a lambda with first argument this deduced
type.  For a base class implementation, the deduced type is `Base`, not
`Derived`, and so we generate and registered an overload which takes a
`Base *` as first argument.  Trying to call this fails if `Base` isn't
registered (e.g.  because it's an implementation detail class that isn't
intended to be exposed to Python) because the type caster for an
unregistered type always fails.

This commit adds a `method_adaptor` function that rebinds a member
function to a derived type member function and otherwise (i.e. regular
functions/lambda) leaves the argument as-is.  This is now used for class
definitions so that they are bound with type being registered rather
than a potential base type.

A closely related fix in this commit is to similarly update the lambdas
used for `def_readwrite` (and related) to bind to the class type being
registered rather than the deduced type so that registering a property
that resolves to a base class member similarly generates a usable
function.

Fixes #854, #910.

Co-Authored-By: Dean Moldovan <dean0x7d@gmail.com>
2017-07-03 17:28:45 -04:00
Dean Moldovan
bdfb50f384 Move tests from test_issues.cpp/py into appropriate files 2017-06-27 10:38:41 +02:00
Jason Rhinelander
4e1e4a580e Allow py::arg().none(false) argument attribute
This attribute lets you disable (or explicitly enable) passing None to
an argument that otherwise would allow it by accepting
a value by raw pointer or shared_ptr.
2017-05-24 13:10:57 -04:00
Jason Rhinelander
0a90b2db71 Don't let PyInstanceMethod hide itself
Python 3's `PyInstanceMethod_Type` hides itself via its `tp_descr_get`,
which prevents aliasing methods via `cls.attr("m2") = cls.attr("m1")`:
instead the `tp_descr_get` returns a plain function, when called on a
class, or a `PyMethod`, when called on an instance.  Override that
behaviour for pybind11 types with a special bypass for
`PyInstanceMethod_Types`.
2017-04-28 11:18:58 -04:00
Jason Rhinelander
d355f2fcca Don't allow mixed static/non-static overloads
We currently fail at runtime when trying to call a method that is
overloaded with both static and non-static methods.  This is something
python won't allow: the object is either a function or an instance, and
can't be both.
2017-04-18 17:17:47 -04:00
Dean Moldovan
e0e2ea3378 Fix overriding static properties in derived classes
Fixes #775.

Assignments of the form `Type.static_prop = value` should be translated to
`Type.static_prop.__set__(value)` except when `isinstance(value, static_prop)`.
2017-04-07 22:41:46 +02:00
Dean Moldovan
dd01665e5a Enable static properties (py::metaclass) by default
Now that only one shared metaclass is ever allocated, it's extremely
cheap to enable it for all pybind11 types.

* Deprecate the default py::metaclass() since it's not needed anymore.
* Allow users to specify a custom metaclass via py::metaclass(handle).
2017-02-23 15:45:26 +01:00
Dean Moldovan
c91f8bd627 Reimplement static properties by extending PyProperty_Type
Instead of creating a new unique metaclass for each type, the builtin
`property` type is subclassed to support static properties. The new
setter/getters always pass types instead of instances in their `self`
argument. A metaclass is still required to support this behavior, but
it doesn't store any data anymore, so a new one doesn't need to be
created for each class. There is now only one common metaclass which
is shared by all pybind11 types.
2017-02-23 15:45:26 +01:00
Jason Rhinelander
1eaacd19f6 Fix debugging output for nameless py::arg_v annotations (#648)
* Fix debugging output for nameless py::arg annotations

This fixes a couple bugs with nameless py::arg() (introduced in #634)
annotations:

- the argument name was being used in debug mode without checking that
  it exists (which would result in the std::string construction throwing
  an exception for being invoked with a nullptr)
- the error output says "keyword arguments", but py::arg_v() can now
  also be used for positional argument defaults.
- the debugging output "in function named 'blah'" was overly verbose:
  changed it to just "in function 'blah'".

* Fix missing space in debug test string

* Moved tests from issues to methods_and_attributes
2017-02-08 08:45:51 +01:00
Jason Rhinelander
e550589b42 Prefer non-converting argument overloads
This changes the function dispatching code for overloaded functions into
a two-pass procedure where we first try all overloads with
`convert=false` for all arguments.  If no function calls succeeds in the
first pass, we then try a second pass where we allow arguments to have
`convert=true` (unless, of course, the argument was explicitly specified
with `py::arg().noconvert()`).

For non-overloaded methods, the two-pass procedure is skipped (we just
make the overload-allowed call).  The second pass is also skipped if it
would result in the same thing (i.e. where all arguments are
`.noconvert()` arguments).
2017-02-03 20:47:17 -05:00
Jason Rhinelander
abc29cad02 Add support for non-converting arguments
This adds support for controlling the `convert` flag of arguments
through the py::arg annotation.  This then allows arguments to be
flagged as non-converting, which the type_caster is able to use to
request different behaviour.

Currently, AFAICS `convert` is only used for type converters of regular
pybind11-registered types; all of the other core type_casters ignore it.
We can, however, repurpose it to control internal conversion of
converters like Eigen and `array`: most usefully to give callers a way
to disable the conversion that would otherwise occur when a
`Eigen::Ref<const Eigen::Matrix>` argument is passed a numpy array that
requires conversion (either because it has an incompatible stride or the
wrong dtype).

Specifying a noconvert looks like one of these:

    m.def("f1", &f, "a"_a.noconvert() = "default"); // Named, default, noconvert
    m.def("f2", &f, "a"_a.noconvert()); // Named, no default, no converting
    m.def("f3", &f, py::arg().noconvert()); // Unnamed, no default, no converting

(The last part--being able to declare a py::arg without a name--is new:
previous py::arg() only accepted named keyword arguments).

Such an non-convert argument is then passed `convert = false` by the
type caster when loading the argument.  Whether this has an effect is up
to the type caster itself, but as mentioned above, this would be
extremely helpful for the Eigen support to give a nicer way to specify
a "no-copy" mode than the custom wrapper in the current PR, and
moreover isn't an Eigen-specific hack.
2017-02-03 20:18:15 -05:00