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.
* Fix warning C26817: Potentially expensive copy of variable 'vh' in range-for loop. Consider making it a const reference (es.71).
* Replace another instance of `for (auto vh : values_and_holders(...))` with `auto vh &` (found by @bstaletic)
Co-authored-by: Michael Goulding <Michael.Goulding@microsoft.com>
Co-authored-by: Yannick Jadoul <yannick.jadoul@belgacom.net>
* Modified Vector STL bind initialization from a buffer type with optimization for simple arrays
* Add subtests to demonstrate processing Python buffer protocol objects with step > 1
* Fixed memoryview step test to only run on Python 3+
* Modified Vector constructor from buffer to return by value for readability
If the default argument value is a class, and not an instance of a
class, `a.value.attr("__repr__")` raises a `ValueError`. Switching to
`repr(a.value)` makes this use case work.
Fixes#2028
* Fix undefined memoryview format
* Add missing <algorithm> header
* Add workaround for py27 array compatibility
* Workaround py27 memoryview behavior
* Fix memoryview constructor from buffer_info
* Workaround PyMemoryView_FromMemory availability in py27
* Fix up memoryview tests
* Update memoryview test from buffer to check signedness
* Use static factory method to create memoryview
* Remove ndim arg from memoryview::frombuffer and add tests
* Allow ndim=0 memoryview and documentation fixup
* Use void* to align to frombuffer method signature
* Add const variants of frombuffer and frommemory
* Add memory view section in doc
* Fix docs
* Add test for null buffer
* Workaround py27 nullptr behavior in test
* Rename frombuffer to from_buffer
This avoids a potential conflict with names in the same scope of the
same name as the embedded module, like namespaces or other global
variables.
Fixes#2172
* Change NAMESPACE_BEGIN and NAMESPACE_END macros into PYBIND11_NAMESPACE_BEGIN and PYBIND11_NAMESPACE_END
* Fix sudden HomeBrew 'python not installed' error
* Sweep difference in 'Class.__init__() must be called when overriding __init__' error message between CPython and PyPy under the rug
* Homebrew updated to 3.8 yesterday.
Co-authored-by: Henry Schreiner <HenrySchreinerIII@gmail.com>
* Error out eval_file
* Enable dynamic attribute support for Pypy >= 6
* Add a test for dynamic attribute support
* Skip test for eval_file on pypy
* Workaround for __qualname__ on PyPy3
* Add a PyPy3.6 7.3.0 build
* Only disable in PyPy3
* Fix travis testing
* No numpy and scipy for pypy
* Enable test on pypy2
* Fix logic in eval_file
* Skip a few tests due to bugs in PyPy
* scipy wheels are broken. make pypy2 a failrue
Co-authored-by: Andreas Kloeckner <inform@tiker.net>
The PyEval_InitThreads() and PyEval_ThreadsInitialized() functions are
now deprecated and will be removed in Python 3.11. Calling
PyEval_InitThreads() now does nothing. The GIL is initialized by
Py_Initialize() since Python 3.7.
For rationale, see #2241, eeb1044818af5b70761deae602c49eba439164dc;
there is a second entry point function defined by the PYBIND11_MODULE
macro that also needs to be annotated as unused.
This change defines a new, portable macro PYBIND11_MAYBE_UNUSED to
mark declarations as unused, and annotates the PYBIND11_MODULE entry
point with this attribute.
The purpose of this annotation is to facilitate dead code detection,
which might otherwise consider the module entry point function dead,
since it isn't otherwise used. (It is only used via FFI.)
This adds support for a `py::args_kw_only()` annotation that can be
specified between `py::arg` annotations to indicate that any following
arguments are keyword-only. This allows you to write:
m.def("f", [](int a, int b) { /* ... */ },
py::arg("a"), py::args_kw_only(), py::arg("b"));
and have it work like Python 3's:
def f(a, *, b):
# ...
with respect to how `a` and `b` arguments are accepted (that is, `a` can
be positional or by keyword; `b` can only be specified by keyword).
Currently user specializations of the form
template <typename itype> struct polymorphic_type_hook<itype, std::enable_if_t<...>> { ... };
will fail if itype is also polymorphic, because the existing specialization will also
be enabled, which leads to 2 equally viable candidates. With this change, user provided
specializations have higher priority than the built in specialization for polymorphic types.
When binding code immediately throws an exception of type
py::error_already_set (e.g. via py::module::import that fails), the
catch block sets an import error as expected. Unfortunately, following
this, the deconstructor of py::error_already_set decides to call
py::detail::get_internals() and set up various internal data structures
of pybind11, which fails given that the error flag is active. The call
stack of this looks as follows:
Py_init_mymodule() -> __cxa_decrement_exception_refcount ->
error_already_set::~error_already_set() ->
gil_scoped_acquire::gil_scoped_acquire() -> detail::get_internals() ->
... -> pybind11::detail::simple_collector() -> uh oh..
The solution is simple: we call detail::get_internals() once before
running any binding code to make sure that the internal data structures
are ready.
This commit introduces the use of C++17-style fold expressions when
casting tuples & the argument lists of functions.
This change can improve performance of the resulting bindings: because
fold expressions have short-circuiting semantics, pybind11 e.g. won't
try to cast the second argument of a function if the first one failed.
This is particularly effective when working with functions that have
many overloads with long argument lists.
* test pair-copyability on C++17 upwards
The stdlib falsely detects containers like M=std::map<T, U>
as copyable, even when one of T and U is not copyable.
Therefore we cannot rely on the stdlib dismissing std::pair<T, M>
by itself, even on C++17.
* fix is_copy_assignable
bind_map used std::is_copy_assignable which suffers from the same problems
as std::is_copy_constructible, therefore the same fix has been applied.
* created tests for copyability
Don't assume that just because the language version is C++17 that the
standard library offers all C++17 features, too. When using clang-6.0
and --std=c++17 on Ubuntu 18.04 with libstdc++, __cpp_sized_deallocation
is false.
When building with `-Werror,-Wmissing-prototypes`, `clang` complains about missing prototypes for functions defined through macro expansions. This PR adds the missing prototypes.
```
error: no previous prototype for function 'pybind11_init_impl_embedded' [
-Werror,-Wmissing-prototypes]
PYBIND11_EMBEDDED_MODULE(embedded, mod) {
^
external/pybind11/include/pybind11/embed.h:61:5: note: expanded from macro 'PYBIND11_EMBEDDED_MODULE'
PYBIND11_EMBEDDED_MODULE_IMPL(name) \
^
external/pybind11/include/pybind11/embed.h:26:23: note: expanded from macro 'PYBIND11_EMBEDDED_MODULE_IMPL'
extern "C" void pybind11_init_impl_##name() { \
^
<scratch space>:380:1: note: expanded from here
pybind11_init_impl_embedded
^
1 error generated.
```
* Adapt to python3.8 C API change
Do `Py_DECREF(type)` on all python objects on deallocation
fix#1946
* Add bare python3.8 build to CI matrix
While numpy/scipy wheels are available, run python3.8 test without them
* fix: Avoid conversion to `int_` rhs argument of enum eq/ne
* test: compare unscoped enum with strings
* suppress comparison to None warning
* test unscoped enum arithmetic and comparision with unsupported type
* Make `overload_cast_impl` available in C++11 mode.
Narrow the scope of the `#if defined(PYBIND11_CPP14)` block around overload_cast to only
cover the parts where C++14 is stricly required. Thus, the implementation in
`pybind11::details::overload_cast_impl` is still available in C++11 mode.
* PR #1581: Modify test to use overload_cast_impl, update docs and change log
The -Wmissing-prototypes Clang warning (or -Wmissing-declarations on
GCC) is very useful to avoid accidents where a function definition in a
source file doesn't match the corresponding declaration in a header
file, as it would warn already during compilation and not much later
during link time.
Unfortunately this means that exported functions defined only in the
source file (usually the ones annotated with `extern "C"`) will cause
this warning to be emitted too (on Clang, GCC has a slightly different
behavior with -Wmissing-declarations and doesn't warn here). This fixes
the warning by providing a declaration right before the definition.
Clang has a bug [1] in x86 Windows that is exposed by the use of lambdas with "unforwardable" prototypes. The error is "error: cannot compile this forwarded non-trivially copyable parameter yet", and the message was introduced in [2] (used to be an assertion).
[1] https://llvm.org/bugs/show_bug.cgi?id=28299
[2] feb1567e07
This is only necessary if `get_internals` is called for the first time in a given module when the running thread is in a GIL-released state.
Fixes#1364
* Test dtype field order in numpy dtype tests
When running tests with NumPy 1.14 or later this test exposes the
"invalid buffer descriptor" error reported in #1274.
* Create dtype_ptr with ordered fields
* Fix casting of time points with non-system-clock duration on Windows
Add explicit `time_point_cast` to time point with duration of system
clock. Fixes Visual Studio compile error.
* Add test case for custom time points casting
In def_readonly and def_readwrite, there is an assertion that the member comes
from the class or a base class:
static_assert(std::is_base_of<C, type>::value, "...");
However, if C and type are the same type, is_base_of will still only be true
if they are the same _non-union_ type. This means we can't define accessors
for the members of a union type because of this assertion.
Update the assertion to test
std::is_same<C, type>::value || std::is_base_of<C, type>::value
which will allow union types, or members of base classes.
Also add a basic unit test for accessing unions.
* Fix async Python functors invoking from multiple C++ threads (#1587)
Ensure GIL is held during functor destruction.
* Add async Python callbacks test that runs in separate Python thread
In some cases the user of pythonbuf needs to allocate the internal
buffer to a specific size e.g. for performance or to enable synchronous
writes to the buffer.
By changing `pythonbuf::d_buffer` to be dynamically allocated we can now
enable these use-cases while still providing the default behavior of
allocating a 1024 byte internal buffer (through a default parameter).
Bazel has a "strict" build model that requires all C++ header files be compilable on their own, and thus must explicitly #include all headers they require (even if de facto header inclusion order means they'd get them "for free"). This adds a couple of headers that are needed (but missing) by this model.
* Fixing order of arguments in call to PyErr_GivenExceptionMatches in pybind11::error_already_set.matches
* Added tests on error_already_set::matches fix for exception base classes
* Fix warning that not including a cmake source or build dir will be a fatal error (it is now on newest CMakes)
* Fixes appveyor
* Travis uses CMake 3.9 for more than a year now
* Travis dropped sudo: false in December
* Dropping Sphinx 2
- clang7: Suppress self-assign warnings; fix missing virtual dtors
- pypy:
- Keep old version (newer stuff breaks)
- Pin packages to extra index for speed
- travis:
- Make docker explicit; remove docker if not needed
- Make commands more verbose (for debugging / repro)
- Make Ubuntu dist explicit per job
- Fix Windows
- Add names to travis
This avoids GIL deadlocking when pybind11 tries to acquire the GIL in a thread that already acquired it using standard Python API (e.g. when running from a Python thread).
* Adds std::deque to the types supported by list_caster in stl.h.
* Adds a new test_deque test in test_stl.{py,cpp}.
* Updates the documentation to include std::deque as a default
supported type.
* Check default holder
-Recognize "std::unique_ptr<T, D>" as a default holder even if "D" doesn't match between base and derived holders
* Add test for unique_ptr<T, D> change
Pybind11 provides a cast operator between opaque void* pointers on the
C++ side and capsules on the Python side. The py::cast<void *>
expression was not aware of this possibility and incorrectly triggered a
compile-time assertion ("Unable to cast type to reference: value is
local to type caster") that is now fixed.
* Support C++17 aligned new statement
This patch makes pybind11 aware of nonstandard alignment requirements in
bound types and passes on this information to C++17 aligned 'new'
operator. Pre-C++17, the behavior is unchanged.
This PR brings the std::array<> caster in sync with the other STL type
casters: to accept an arbitrary sequence as input (rather than a list,
which is too restrictive).
* Fix for Issue #1258
list_caster::load method will now check for a Python string and prevent its automatic conversion to a list.
This should fix the issue "pybind11/stl.h converts string to vector<string> #1258" (https://github.com/pybind/pybind11/issues/1258)
* Added tests for fix of issue #1258
* Changelog: stl string auto-conversion
* Fix potential crash when calling an overloaded function
The crash would occur if:
- dispatcher() uses two-pass logic (because the target is overloaded and some arguments support conversions)
- the first pass (with conversions disabled) doesn't find any matching overload
- the second pass does find a matching overload, but its return value can't be converted to Python
The code for formatting the error message assumed `it` still pointed to the selected overload,
but during the second-pass loop `it` was nullptr. Fix by setting `it` correctly if a second-pass
call returns a nullptr `handle`. Add a new test that segfaults without this fix.
* Make overload iteration const-correct so we don't have to iterate again on second-pass error
* Change test_error_after_conversions dependencies to local classes/variables
This commit addresses an inefficiency in how enums are created in
pybind11. Most of the enum_<> implementation is completely generic --
however, being a template class, it ended up instantiating vast amounts
of essentially identical code in larger projects with many enums.
This commit introduces a generic non-templated helper class that is
compatible with any kind of enumeration. enum_ then becomes a thin
wrapper around this new class.
The new enum_<> API is designed to be 100% compatible with the old one.
object_api::operator[] has a powerful overload for py::handle that can
accept slices, tuples (for NumPy), etc.
Lists, sequences, and tuples provide their own specialized operator[],
which unfortunately disables this functionality. This is accidental, and
the purpose of this commit is to re-enable the more general behavior.
This commit is tangentially related to the previous one in that it makes
py::handle/py::object et al. behave more like their Python counterparts.
This commit revamps the object_api class so that it maps most C++
operators to their Python analogs. This makes it possible to, e.g.
perform arithmetic using a py::int_ or py::array.
* check for already existing enum value added; added test
* added enum value name to exception message
* test for defining enum with multiple identical names moved to test_enum.cpp/py
This PR adds a new py::ellipsis() method which can be used in
conjunction with NumPy's generalized slicing support. For instance,
the following is now valid (where "a" is a NumPy array):
py::array b = a[py::make_tuple(0, py::ellipsis(), 0)];
* stl.h: propagate return value policies to type-specific casters
Return value policies for containers like those handled in in 'stl.h'
are currently broken.
The problem is that detail::return_value_policy_override<C>::policy()
always returns 'move' when given a non-pointer/reference type, e.g.
'std::vector<...>'.
This is sensible behavior for custom types that are exposed via
'py::class_<>', but it does not make sense for types that are handled by
other type casters (STL containers, Eigen matrices, etc.).
This commit changes the behavior so that
detail::return_value_policy_override only becomes active when the type
caster derives from type_caster_generic.
Furthermore, the override logic is called recursively in STL type
casters to enable key/value-specific behavior.
* Switching deprecated Thread Local Storage (TLS) usage in Python 3.7 to Thread Specific Storage (TSS)
* Changing Python version from 3.6 to 3.7 for Travis CI, to match brew's version of Python 3
* Introducing PYBIND11_ macros to switch between TLS and TSS API
The current code requires implicitly that integral types are cast-able to floating point. In case of strongly-typed integrals (e.g. as explained at http://www.ilikebigbits.com/blog/2014/5/6/type-safe-identifiers-in-c) this is not always the case.
This commit uses SFINAE to move the numeric conversions into separate `cast()` implementations to avoid the issue.
If an exception is thrown during module initialization, the
error_already_set destructor will try to call `get_internals()` *after*
setting Python's error indicator, resulting in a `SystemError: ...
returned with an error set`.
Fix that by temporarily stashing away the error indicator in the
destructor.
When using pybind11 to bind enums on MSVC and warnings (/W4) enabled,
the following warning pollutes builds. This fix renames one of the
occurrences.
pybind11\include\pybind11\pybind11.h(1398): warning C4459: declaration of 'self' hides global declaration
pybind11\include\pybind11\operators.h(41): note: see declaration of 'pybind11::detail::self'
* Add basic support for tag-based static polymorphism
Sometimes it is possible to look at a C++ object and know what its dynamic type is,
even if it doesn't use C++ polymorphism, because instances of the object and its
subclasses conform to some other mechanism for being self-describing; for example,
perhaps there's an enumerated "tag" or "kind" member in the base class that's always
set to an indication of the correct type. This might be done for performance reasons,
or to permit most-derived types to be trivially copyable. One of the most widely-known
examples is in LLVM: https://llvm.org/docs/HowToSetUpLLVMStyleRTTI.html
This PR permits pybind11 to be informed of such conventions via a new specializable
detail::polymorphic_type_hook<> template, which generalizes the previous logic for
determining the runtime type of an object based on C++ RTTI. Implementors provide
a way to map from a base class object to a const std::type_info* for the dynamic
type; pybind11 then uses this to ensure that casting a Base* to Python creates a
Python object that knows it's wrapping the appropriate sort of Derived.
There are a number of restrictions with this tag-based static polymorphism support
compared to pybind11's existing support for built-in C++ polymorphism:
- there is no support for this-pointer adjustment, so only single inheritance is permitted
- there is no way to make C++ code call new Python-provided subclasses
- when binding C++ classes that redefine a method in a subclass, the .def() must be
repeated in the binding for Python to know about the update
But these are not much of an issue in practice in many cases, the impact on the
complexity of pybind11's innards is minimal and localized, and the support for
automatic downcasting improves usability a great deal.
The property returns the enum_ value as a string.
For example:
>>> import module
>>> module.enum.VALUE
enum.VALUE
>>> str(module.enum.VALUE)
'enum.VALUE'
>>> module.enum.VALUE.name
'VALUE'
This is actually the equivalent of Boost.Python "name" property.
As reported in #1349, clang before 3.5 can segfault on a function-local
variable referenced inside a lambda. This moves the function-local
static into a separate function that the lambda can invoke to avoid the
issue.
Fixes#1349
This reimplements the version check to avoid sscanf (which has
reportedly started throwing warnings under MSVC, even when used
perfectly safely -- #1314). It also extracts the mostly duplicated
parts of PYBIND11_MODULE/PYBIND11_PLUGIN into separate macros.
- PYBIND11_MAKE_OPAQUE now takes ... rather than a single argument and
expands it with __VA_ARGS__; this lets templated, comma-containing
types get through correctly.
- Adds a new macro PYBIND11_TYPE() that lets you pass the type into a
macro as a single argument, such as:
PYBIND11_OVERLOAD(PYBIND11_TYPE(R<1,2>), PYBIND11_TYPE(C<3,4>), func)
Unfortunately this only works for one macro call: to forward the
argument on to the next macro call (without the processor breaking it
up again) requires also adding the PYBIND11_TYPE(...) to type macro
arguments in the PYBIND11_OVERLOAD_... macro chain.
- updated the documentation with these two changes, and use them at a couple
places in the test suite to test that they work.
This updates the `py::init` constructors to only use brace
initialization for aggregate initiailization if there is no constructor
with the given arguments.
This, in particular, fixes the regression in #1247 where the presence of
a `std::initializer_list<T>` constructor started being invoked for
constructor invocations in 2.2 even when there was a specific
constructor of the desired type.
The added test case demonstrates: without this change, it fails to
compile because the `.def(py::init<std::vector<int>>())` constructor
tries to invoke the `T(std::initializer_list<std::vector<int>>)`
constructor rather than the `T(std::vector<int>)` constructor.
By only using `new T{...}`-style construction when a `T(...)`
constructor doesn't exist, we should bypass this by while still allowing
`py::init<...>` to be used for aggregate type initialization (since such
types, by definition, don't have a user-declared constructor).
* Fix segfault when reloading interpreter with external modules
When embedding the interpreter and loading external modules in that
embedded interpreter, the external module correctly shares its
internals_ptr with the one in the embedded interpreter. When the
interpreter is shut down, however, only the `internals_ptr` local to
the embedded code is actually reset to nullptr: the external module
remains set.
The result is that loading an external pybind11 module, letting the
interpreter go through a finalize/initialize, then attempting to use
something in the external module fails because this external module is
still trying to use the old (destroyed) internals. This causes
undefined behaviour (typically a segfault).
This commit fixes it by adding a level of indirection in the internals
path, converting the local internals variable to `internals **` instead
of `internals *`. With this change, we can detect a stale internals
pointer and reload the internals pointer (either from a capsule or by
creating a new internals instance).
(No issue number: this was reported on gitter by @henryiii and @aoloe).
The anonymous struct nested in a union triggers a -Wnested-anon-type
warning ("anonymous types declared in an anonymous union are an
extension") under clang (#1204). This names the struct and defines it
out of the definition of `instance` to get around to warning (and makes
the code slightly simpler).
PEP8 indicates (correctly, IMO) that when an annotation is present, the
signature should include spaces around the equal sign, i.e.
def f(x: int = 1): ...
instead of
def f(x: int=1): ...
(in the latter case the equal appears to bind to the type, not to the
argument).
pybind11 signatures always includes a type annotation so we can always
add the spaces.
When using the mixed position + vararg path, pybind over inc_ref's
the vararg positions. Printing the ref_count() of `item` before
and after this change you see:
Before change:
```
refcount of item before assign 3
refcount of item after assign 5
```
After change
```
refcount of item before assign 3
refcount of item after assign 4
```
The `py::args` or `py::kwargs` arguments aren't properly referenced
when added to the function_call arguments list: their reference counts
drop to zero if the first (non-converting) function call fails, which
means they might be cleaned up before the second pass call runs.
This commit adds a couple of extra `object`s to the `function_call`
where we can stash a reference to them when needed to tie their
lifetime to the function_call object's lifetime.
(Credit to YannickJadoul for catching and proposing a fix in #1223).
In the latest MSVC in C++17 mode including Eigen causes warnings:
warning C4996: 'std::unary_negate<_Fn>': warning STL4008: std::not1(),
std::not2(), std::unary_negate, and std::binary_negate are deprecated in
C++17. They are superseded by std::not_fn(). You can define
_SILENCE_CXX17_NEGATORS_DEPRECATION_WARNING or
_SILENCE_ALL_CXX17_DEPRECATION_WARNINGS to acknowledge that you have
received this warning.
This disables 4996 for the Eigen includes.
Catch generates a similar warning for std::uncaught_exception, so
disable the warning there, too.
In both cases this is temporary; we can (and should) remove the warnings
disabling once new upstream versions of Eigen and Catch are available
that address the warning. (The Catch one, in particular, looks to be
fixed in upstream master, so will probably be fixed in the next (2.0.2)
release).
Pybind11's default conversion to int always produces a long on Python 2 (`int`s and `long`s were unified in Python 3). This patch fixes `int` handling to match Python 2 on Python 2; for short types (`size_t` or smaller), the number will be returned as an `int` if possible, otherwise `long`. Requires Python 2.5+.
This is needed for things like `sys.exit`, which refuse to accept a `long`.
This commit turns on `-Wdeprecated` in the test suite and fixes several
associated deprecation warnings that show up as a result:
- in C++17 `static constexpr` members are implicitly inline; our
redeclaration (needed for C++11/14) is deprecated in C++17.
- various test suite classes have destructors and rely on implicit copy
constructors, but implicit copy constructor definitions when a
user-declared destructor is present was deprecated in C++11.
- Eigen also has various implicit copy constructors, so just disable
`-Wdeprecated` in `eigen.h`.
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.
A few fixes related to how we set `__qualname__` and how we show the
type name in function signatures:
- `__qualname__` isn't supposed to have the module name at the
beginning, but we've been putting it there. This removes it, while
keeping the `Nested.Class` name chaining.
- print `__module__.__qualname__` rather than `type->tp_name`; the
latter doesn't work properly for nested classes, so we would get
`module.B` rather than `module.A.B` for a class `B` with parent `A`.
This also unifies the Python 3 and PyPy code. Fixes#1166.
- This now sets a `__qualname__` attribute on the type (as would happen
in Python 3.3+) for Python <3.3, including PyPy. While not particularly
important to have in earlier Python versions, it's useful for us to be
able to extracted the nested name, which is why `__qualname__` was
invented in the first place.
- Added tests for the above.
Building with the (VS2017) /permissive- flag puts the compiler into
stricter standards-compliant mode. It shouldn't cause the compiler to
work differently--it just disallows some non-conforming code--so should
be perfectly fine for the test suite under all VS2017 builds.
This commit also fixes one failure under non-permissive mode.
This fixes a bug introduced in b68959e822
when passing in a two-dimensional, but conformable, array as the value
for a compile-time Eigen vector (such as VectorXd or RowVectorXd). The
commit switched to using numpy to copy into the eigen data, but this
broke the described case because numpy refuses to broadcast a (N,1)
into a (N).
This commit fixes it by squeezing the input array whenever the output
array is 1-dimensional, which will let the problematic case through.
(This shouldn't squeeze inappropriately as dimension compatibility is
already checked for conformability before getting to the copy code).
When using `method_adaptor` (usually implicitly via a `cl.def("f",
&D::f)`) a compilation failure results if `f` is actually a method of
an inaccessible base class made public via `using`, such as:
class B { public: void f() {} };
class D : private B { public: using B::f; };
pybind deduces `&D::f` as a `B` member function pointer. Since the base
class is inaccessible, the cast in `method_adaptor` from a base class
member function pointer to derived class member function pointer isn't
valid, and a cast failure results.
This was sort of a regression in 2.2, which introduced `method_adaptor`
to do the expected thing when the base class *is* accessible. It wasn't
actually something that *worked* in 2.1, though: you wouldn't get a
compile-time failure, but the method was not callable (because the `D *`
couldn't be cast to a `B *` because of the access restriction). As a
result, you'd simply get a run-time failure if you ever tried to call
the function (this is what #855 fixed).
Thus the change in 2.2 essentially promoted a run-time failure to a
compile-time failure, so isn't really a regression.
This commit simply adds a `static_assert` with an accessible-base-class
check so that, rather than just a cryptic cast failure, you get
something more informative (along with a suggestion for a workaround).
The workaround is to use a lambda, e.g.:
class Derived : private Base {
public:
using Base::f;
};
// In binding code:
//cl.def("f", &Derived::f); // fails: &Derived::f is actually a base
// class member function pointer
cl.def("f", [](Derived &self) { return self.f(); });
This is a bit of a nuissance (especially if there are a bunch of
arguments to forward), but I don't really see another solution.
Fixes#1124
This changes the caster to return a reference to a (new) local `CharT`
type caster member so that binding lvalue-reference char arguments
works (currently it results in a compilation failure).
Fixes#1116
`type_descr` is now applied only to the final signature so that it only
marks the argument types, but not nested types (e.g. for tuples) or
return types.
MSCV does not allow `&typeid(T)` in constexpr contexts, but the string
part of the type signature can still be constexpr. In order to avoid
`typeid` as long as possible, `descr` is modified to collect type
information as template parameters instead of constexpr `typeid`.
The actual `std::type_info` pointers are only collected in the end,
as a `constexpr` (gcc/clang) or regular (MSVC) function call.
Not only does it significantly reduce binary size on MSVC, gcc/clang
benefit a little bit as well, since they can skip some intermediate
`std::type_info*` arrays.
The current C++14 constexpr signatures don't require relaxed constexpr,
but only `auto` return type deduction. To get around this in C++11,
the type caster's `name()` static member functions are turned into
`static constexpr auto` variables.
E.g. trying to convert a `list` to a `std::vector<int>` without
including <pybind11/stl.h> will now raise an error with a note that
suggests checking the headers.
The note is only appended if `std::` is found in the function
signature. This should only be the case when a header is missing.
E.g. when stl.h is included, the signature would contain `List[int]`
instead of `std::vector<int>` while using stl_bind.h would produce
something like `MyVector`. Similarly for `std::map`/`Dict`, `complex`,
`std::function`/`Callable`, etc.
There's a possibility for false positives, but it's pretty low.
To avoid an ODR violation in the test suite while testing
both `stl.h` and `std_bind.h` with `std::vector<bool>`,
the `py::bind_vector<std::vector<bool>>` test is moved to
the secondary module (which does not include `stl.h`).
There are two separate additions:
1. `py::hash(obj)` is equivalent to the Python `hash(obj)`.
2. `.def(hash(py::self))` registers the hash function defined by
`std::hash<T>` as the Python hash function.
The lookup of the `self` type and value pointer are moved out of
template code and into `dispatcher`. This brings down the binary
size of constructors back to the level of the old placement-new
approach. (It also avoids a second lookup for `init_instance`.)
With this implementation, mixing old- and new-style constructors
in the same overload set may result in some runtime overhead for
temporary allocations/deallocations, but this should be fine as
old style constructors are phased out.
Creating an instance of of a pybind11-bound type caused a reference leak in the
associated Python type object, which could prevent these from being collected
upon interpreter shutdown. This commit fixes that issue for all types that are
defined in a scope (e.g. a module). Unscoped anonymous types (e.g. custom
iterator types) always retain a positive reference count to prevent their
collection.
The current PYBIND11_INTERNALS_ID depends on the version of the library
in order to isolate binary incompatible internals capsules. However,
this does not preclude conflicts between modules built from different
(binary incompatible) commits with the same version number.
For example, if one module was built with an early v2.2.dev and
submitted to PyPI, it could not be loaded alongside a v2.2.x release
module -- it would segfault because of incompatible internals with
the same ID.
This PR changes the ID to depend on PYBIND11_INTERNALS_VERSION which is
independent of the main library version. It's an integer which should be
incremented whenever a binary incompatible change is made to internals.
PYBIND11_INTERNALS_KIND is also introduced for a similar reason.
The same versioning scheme is also applied to `type_info` and the
`module_local` type attribute.
The "see above" comment being referenced in the code comments isn't
"above" anymore; copy the later factory init comment into the first
constructor block to fix it.
The main point of `py::module_local` is to make the C++ -> Python cast
unique so that returning/casting a C++ instance is well-defined.
Unfortunately it also makes loading unique, but this isn't particularly
desirable: when an instance contains `Type` instance there's no reason
it shouldn't be possible to pass that instance to a bound function
taking a `Type` parameter, even if that function is in another module.
This commit solves the issue by allowing foreign module (and global)
type loaders have a chance to load the value if the local module loader
fails. The implementation here does this by storing a module-local
loading function in a capsule in the python type, which we can then call
if the local (and possibly global, if the local type is masking a global
type) version doesn't work.
This reimplements the py::init<...> implementations using the various
functions added to support `py::init(...)`, and moves the implementing
structs into `detail/init.h` from `pybind11.h`. It doesn't simply use a
factory directly, as this is a very common case and implementation
without an extra lambda call is a small but useful optimization.
This, combined with the previous lazy initialization, also avoids
needing placement new for `py::init<...>()` construction: such
construction now occurs via an ordinary `new Type(...)`.
A consequence of this is that it also fixes a potential bug when using
multiple inheritance from Python: it was very easy to write classes
that double-initialize an existing instance which had the potential to
leak for non-pod classes. With the new implementation, an attempt to
call `__init__` on an already-initialized object is now ignored. (This
was already done in the previous commit for factory constructors).
This change exposed a few warnings (fixed here) from deleting a pointer
to a base class with virtual functions but without a virtual destructor.
These look like legitimate warnings that we shouldn't suppress; this
adds virtual destructors to the appropriate classes.
This allows you to use:
cls.def(py::init(&factory_function));
where `factory_function` returns a pointer, holder, or value of the
class type (or a derived type). Various compile-time checks
(static_asserts) are performed to ensure the function is valid, and
various run-time type checks where necessary.
Some other details of this feature:
- The `py::init` name doesn't conflict with the templated no-argument
`py::init<...>()`, but keeps the naming consistent: the existing
templated, no-argument one wraps constructors, the no-template,
function-argument one wraps factory functions.
- If returning a CppClass (whether by value or pointer) when an CppAlias
is required (i.e. python-side inheritance and a declared alias), a
dynamic_cast to the alias is attempted (for the pointer version); if
it fails, or if returned by value, an Alias(Class &&) constructor
is invoked. If this constructor doesn't exist, a runtime error occurs.
- for holder returns when an alias is required, we try a dynamic_cast of
the wrapped pointer to the alias to see if it is already an alias
instance; if it isn't, we raise an error.
- `py::init(class_factory, alias_factory)` is also available that takes
two factories: the first is called when an alias is not needed, the
second when it is.
- Reimplement factory instance clearing. The previous implementation
failed under python-side multiple inheritance: *each* inherited
type's factory init would clear the instance instead of only setting
its own type value. The new implementation here clears just the
relevant value pointer.
- dealloc is updated to explicitly set the leftover value pointer to
nullptr and the `holder_constructed` flag to false so that it can be
used to clear preallocated value without needing to rebuild the
instance internals data.
- Added various tests to test out new allocation/deallocation code.
- With preallocation now done lazily, init factory holders can
completely avoid the extra overhead of needing an extra
allocation/deallocation.
- Updated documentation to make factory constructors the default
advanced constructor style.
- If an `__init__` is called a second time, we have two choices: we can
throw away the first instance, replacing it with the second; or we can
ignore the second call. The latter is slightly easier, so do that.
An alias can be used for two main purposes: to override virtual methods,
and to add some extra data to a class needed for the pybind-wrapper.
Both of these absolutely require that the wrapped class be polymorphic
so that virtual dispatch and destruction, respectively, works.
`function_signature_t` extracts the function type from a function,
function pointer, or lambda.
`is_lambda` (which is really
`is_not_a_function_or_pointer_or_member_pointer`, but that name is a
bit too long) checks whether the type is (in the approprate context) a
lambda.
`is_function_pointer` checks whether the type is a pointer to a
function.
We currently allocate instance values when creating the instance itself
(except when constructing the instance for a `cast()`), but there is no
particular reason to do so: the instance itself and the internals (for
a non-simple layout) are allocated via Python, with no reason to
expect better locality from the invoked `operator new`. Moreover, it
makes implementation of factory function constructors trickier and
slightly less efficient: they don't use the pre-eallocate the memory,
which means there is a pointless allocation and free.
This commit makes the allocation lazy: instead of preallocating when
creating the instance, the allocation happens when the instance is
first loaded (if null at that time).
In addition to making it more efficient to deal with cases that don't
need preallocation, this also allows for a very slight performance
increase by not needing to look up the instances types during
allocation. (There is a lookup during the eventual load, of course, but
that is happening already).
