* 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.
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.
* 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
* 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.
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.
* 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.
- 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.
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).
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`.
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 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.
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.
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 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 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.
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).
This adds a PYBIND11_NAMESPACE macro that expands to the `pybind11`
namespace with hidden visibility under gcc-type compilers, and otherwise
to the plain `pybind11`. This then forces hidden visibility on
everything in pybind, solving the visibility issues discussed at end
end of #949.
Attempting to mix py::module_local and non-module_local classes results
in some unexpected/undesirable behaviour:
- if a class is registered non-local by some other module, a later
attempt to register it locally fails. It doesn't need to: it is
perfectly acceptable for the local registration to simply override
the external global registration.
- going the other way (i.e. module `A` registers a type `T` locally,
then `B` registers the same type `T` globally) causes a more serious
issue: `A.T`'s constructors no longer work because the `self` argument
gets converted to a `B.T`, which then fails to resolve.
Changing the cast precedence to prefer local over global fixes this and
makes it work more consistently, regardless of module load order.
This commit adds a `py::module_local` attribute that lets you confine a
registered type to the module (more technically, the shared object) in
which it is defined, by registering it with:
py::class_<C>(m, "C", py::module_local())
This will allow the same C++ class `C` to be registered in different
modules with independent sets of class definitions. On the Python side,
two such types will be completely distinct; on the C++ side, the C++
type resolves to a different Python type in each module.
This applies `py::module_local` automatically to `stl_bind.h` bindings
when the container value type looks like something global: i.e. when it
is a converting type (for example, when binding a `std::vector<int>`),
or when it is a registered type itself bound with `py::module_local`.
This should help resolve potential future conflicts (e.g. if two
completely unrelated modules both try to bind a `std::vector<int>`.
Users can override the automatic selection by adding a
`py::module_local()` or `py::module_local(false)`.
Note that this does mildly break backwards compatibility: bound stl
containers of basic types like `std::vector<int>` cannot be bound in one
module and returned in a different module. (This can be re-enabled with
`py::module_local(false)` as described above, but with the potential for
eventual load conflicts).
The builtin exception handler currently doesn't work across modules
under clang/libc++ for builtin pybind exceptions like
`pybind11::error_already_set` or `pybind11::stop_iteration`: under
RTLD_LOCAL module loading clang considers each module's exception
classes distinct types. This then means that the base exception
translator fails to catch the exceptions and the fall through to the
generic `std::exception` handler, which completely breaks things like
`stop_iteration`: only the `stop_iteration` of the first module loaded
actually works properly; later modules raise a RuntimeError with no
message when trying to invoke their iterators.
For example, two modules defined like this exhibit the behaviour under
clang++/libc++:
z1.cpp:
#include <pybind11/pybind11.h>
#include <pybind11/stl_bind.h>
namespace py = pybind11;
PYBIND11_MODULE(z1, m) {
py::bind_vector<std::vector<long>>(m, "IntVector");
}
z2.cpp:
#include <pybind11/pybind11.h>
#include <pybind11/stl_bind.h>
namespace py = pybind11;
PYBIND11_MODULE(z2, m) {
py::bind_vector<std::vector<double>>(m, "FloatVector");
}
Python:
import z1, z2
for i in z2.FloatVector():
pass
results in:
Traceback (most recent call last):
File "zs.py", line 2, in <module>
for i in z2.FloatVector():
RuntimeError
This commit fixes the issue by adding a new exception translator each
time the internals pointer is initialized from python builtins: this
generally means the internals data was initialized by some other
module. (The extra translator(s) are skipped under libstdc++).
This commit adds a PYBIND11_UNSHARED_STATIC_LOCALS macro that forces a
function to have hidden visibility under gcc and gcc-compatible
compilers. gcc, in particular, needs this to to avoid sharing static
local variables across modules (which happens even under a RTLD_LOCAL
dlopen()!). clang doesn't appear to have this issue, but the forced
visibility on internal pybind functions certainly won't hurt it and icc.
This updates the workaround from #862 to use this rather than the
version-specific template.
The fix for #960 could result a type being registered multiple times if
its `__init__` is called multiple times. This can happen perfectly
ordinarily when python-side multiple inheritance is involved: for
example, with a diamond inheritance pattern with each intermediate
classes invoking the parent constructor.
With the change in #960, the multiple `__init__` calls meant
`register_instance` was called multiple times, but the deletion only
deleted it once. Thus, if a future instance of the same type was
allocated at the same location, pybind would pick it up as a registered
type.
This fixes the issue by tracking whether a value pointer has been
registered to avoid both double-registering it. (There's also a slight
optimization of not needing to do a registered_instances lookup when the
type is known not registered, but this is secondary).
The instance registration for offset base types fails (under macOS, with
a segfault) in the presense of virtual base types. The issue occurs
when trying to `static_cast<Base *>(derived_ptr)` when `derived_ptr` has
been allocated (via `operator new`) but not initialized.
This commit fixes the issue by moving the addition to
`registered_instances` into `init_holder` rather than immediately after
value pointer allocation.
This also renames it to `init_instance` since it does more than holder
initialization now. (I also further renamed `init_holder_helper` to
`init_holder` since `init_holder` isn't used anymore).
Fixes#959.
Pre-C++17, std::pair can technically have an copy constructor even
though it can't actually be invoked without a compilation failure (due
to the underlying types being non-copyable). Most stls, including
libc++ since ~3.4, use the C++17 behaviour of not exposing an uncallable
copy constructor, but FreeBSD deliberately broke their libc++ to
preserve the nonsensical behaviour
(https://svnweb.freebsd.org/base?view=revision&revision=261801).
This updates pybind's internal `is_copy_constructible` to also detect
the std::pair case under pre-C++17.
This also everything (except for a couple cases in the internal version)
to use the internal `is_copy_constructible` rather than
`std::is_copy_constructible`.
This adds support for implicit conversions to bool from Python types
with `__bool__` (Python 3) or `__nonzero__` (Python 2) attributes, and
adds direct (i.e. non-converting) support for numpy bools.
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).
PR #936 broke the ability to return a pointer to a stl container (and,
likewise, to a tuple) because the added deduced type matched a
non-const pointer argument: the pointer-accepting `cast` in
PYBIND11_TYPE_CASTER had a `const type *`, which is a worse match for a
non-const pointer than the universal reference template #936 added.
This changes the provided TYPE_CASTER cast(ptr) to take the pointer by
template arg (so that it will accept either const or non-const pointer).
It has two other effects: it slightly reduces .so size (because many
type casters never actually need the pointer cast at all), and it allows
type casters to provide their untemplated pointer `cast()` that will
take precedence over the templated version provided in the macro.
The value and holder iterator code had a past-the-end iterator
dereference. While of course invalid, the dereference didn't actually
cause any problems (which is why it wasn't caught before) because the
dereferenced value is never actually used and `vector` implementations
appear to allow dereferencing the past-the-end iterator. Under a MSVC
debug build, however, it fails a debug assertion and aborts.
This amends the iterator to just store and use a pointer to the vector
(rather than adding a second past-the-end iterator member), checking the
type index against the type vector size.
ICC was reporting that `try_direct_conversions()` cannot be `constexpr`
because `handle` is not a literal type. The fix removes `constexpr`
from the function since it isn't strictly needed.
This commit also suppresses new false positive warnings which mostly
appear in constexpr contexts (where the compiler knows conversions are
safe).
This updates the std::tuple, std::pair and `stl.h` type casters to
forward their contained value according to whether the container being
cast is an lvalue or rvalue reference. This fixes an issue where
subcaster casts were always called with a const lvalue which meant
nested type casters didn't have the desired `cast()` overload invoked.
For example, this caused Eigen values in a tuple to end up with a
readonly flag (issue #935) and made it impossible to return a container
of move-only types (issue #853).
This fixes both issues by adding templated universal reference `cast()`
methods to the various container types that forward container elements
according to the container reference type.
The std::pair caster can be written as a special case of the std::tuple
caster; this combines them via a base `tuple_caster` class (which is
essentially identical to the previous std::tuple caster).
This also removes the special empty tuple base case: returning an empty
tuple is relatively rare, and the base case still works perfectly well
even when the tuple types is an empty list.
When casting to an unsigned type from a python 2 `int`, we currently
cast using `(unsigned long long) PyLong_AsUnsignedLong(src.ptr())`.
If the Python cast fails, it returns (unsigned long) -1, but then we
cast this to `unsigned long long`, which means we get 4294967295, but
because that isn't equal to `(unsigned long long) -1`, we don't detect
the failure.
This commit moves the unsigned casting into a `detail::as_unsigned`
function which, upon error, casts -1 to the final type, and otherwise
casts the return value to the final type to avoid the problematic double
cast when an error occurs.
The error most commonly shows up wherever `long` is 32-bits (e.g. under
both 32- and 64-bit Windows, and under 32-bit linux) when passing a
negative value to a bound function taking an `unsigned long`.
Fixes#929.
The added tests also trigger a latent segfault under PyPy: when casting
to an integer smaller than `long` (e.g. casting to a `uint32_t` on a
64-bit `long` architecture) we check both for a Python error and also
that the resulting intermediate value will fit in the final type. If
there is no conversion error, but we get a value that would overflow, we
end up calling `PyErr_ExceptionMatches()` illegally: that call is only
allowed when there is a current exception. Under PyPy, this segfaults
the test suite. It doesn't appear to segfault under CPython, but the
documentation suggests that it *could* do so. The fix is to only check
for the exception match if we actually got an error.
Using `std::type_info::operator==` fails under libc++ because the .so
is loaded with RTLD_LOCAL. libc++ considers types under such .sos
distinct, and so comparing typeid() values directly isn't going to work.
This adds a custom hasher and equality class for the type lookup maps
when not under stdlibc++, and adds a `detail::same_type` function to
perform the equality test. It also converts a few pointer arguments to
const lvalue references, particularly since doing the pointer
comparison wasn't technically valid to being with (though in practice,
appeared to work everywhere).
This fixes#912.
Fixes the issue as described in the comments of commit e27ea47. This
just adds `enable_if_t<std::is_move_constructible<T>::value>` to
`make_move_constructor`. The change fixes MSVC and is harmless with
other compilers.
This commit allows multiple inheritance of pybind11 classes from
Python, e.g.
class MyType(Base1, Base2):
def __init__(self):
Base1.__init__(self)
Base2.__init__(self)
where Base1 and Base2 are pybind11-exported classes.
This requires collapsing the various builtin base objects
(pybind11_object_56, ...) introduced in 2.1 into a single
pybind11_object of a fixed size; this fixed size object allocates enough
space to contain either a simple object (one base class & small* holder
instance), or a pointer to a new allocation that can contain an
arbitrary number of base classes and holders, with holder size
unrestricted.
* "small" here means having a sizeof() of at most 2 pointers, which is
enough to fit unique_ptr (sizeof is 1 ptr) and shared_ptr (sizeof is 2
ptrs).
To minimize the performance impact, this repurposes
`internals::registered_types_py` to store a vector of pybind-registered
base types. For direct-use pybind types (e.g. the `PyA` for a C++ `A`)
this is simply storing the same thing as before, but now in a vector;
for Python-side inherited types, the map lets us avoid having to do a
base class traversal as long as we've seen the class before. The
change to vector is needed for multiple inheritance: Python types
inheriting from multiple registered bases have one entry per base.
Passing utf8 encoded strings from python to a C++ function taking a
std::string was broken. The previous version was trying to call
'PyUnicode_FromObject' on this data, which failed to convert the string
to unicode with the default ascii codec. Also this incurs an unnecessary
conversion to unicode for data this is immediately converted back to
utf8.
Fix by treating python 2 strings the same python 3 bytes objects, and just
copying over the data if possible.
This reimplements the std::reference_wrapper<T> caster to be a shell
around the underlying T caster (rather than assuming T is a generic
type), which lets it work for things like `std::reference_wrapper<int>`
or anything else custom type caster with a lvalue cast operator.
This also makes it properly fail when None is provided, just as an
ordinary lvalue reference argument would similarly fail.
This also adds a static assert to test that T has an appropriate type
caster. It triggers for casters like `std::pair`, which have
return-by-value cast operators. (In theory this could be supported by
storing a local temporary for such types, but that's beyond the scope
of this PR).
This also replaces `automatic` or `take_ownership` return value policies
with `automatic_reference` as taking ownership of a reference inside a
reference_wrapper is not valid.
This extends py::vectorize to automatically pass through
non-vectorizable arguments. This removes the need for the documented
"explicitly exclude an argument" workaround.
Vectorization now applies to arithmetic, std::complex, and POD types,
passed as plain value or by const lvalue reference (previously only
pass-by-value types were supported). Non-const lvalue references and
any other types are passed through as-is.
Functions with rvalue reference arguments (whether vectorizable or not)
are explicitly prohibited: an rvalue reference is inherently not
something that can be passed multiple times and is thus unsuitable to
being in a vectorized function.
The vectorize returned value is also now more sensitive to inputs:
previously it would return by value when all inputs are of size 1; this
is now amended to having all inputs of size 1 *and* 0 dimensions. Thus
if you pass in, for example, [[1]], you get back a 1x1, 2D array, while
previously you got back just the resulting single value.
Vectorization of member function specializations is now also supported
via `py::vectorize(&Class::method)`; this required passthrough support
for the initial object pointer on the wrapping function pointer.
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.
This commit allows type_casters to allow their local values to be moved
away, rather than copied, when the type caster instance itself is an rvalue.
This only applies (automatically) to type casters using
PYBIND11_TYPE_CASTER; the generic type type casters don't own their own
pointer, and various value casters (e.g. std::string, std::pair,
arithmetic types) already cast to an rvalue (i.e. they return by value).
This updates various calling code to attempt to get a movable value
whenever the value is itself coming from a type caster about to be
destroyed: for example, when constructing an std::pair or various stl.h
containers. For types that don't support value moving, the cast_op
falls back to an lvalue cast.
There wasn't an obvious place to add the tests, so I added them to
test_copy_move_policies, but also renamed it to drop the _policies as it
now tests more than just policies.
This changes javadoc-style documenting comments from:
/** Text starts here
* and continues here
*/
to:
/**
* Test starts here
* and continues here
*/
which looks a little better, and also matches the javadoc-recommended
way of writing documenting comments.
Under gcc, the `static internals *internals_ptr` is shared across .so's,
which breaks for obvious reasons.
This commit fixes it by moving the static pointer declaration into a
pybind-version-templated function.
Many of our `is_none()` checks in type caster loading return true, but
this should really be considered a deferral so that, for example, an
overload with a `py::none` argument would win over one that takes
`py::none` as a null option.
This keeps None-accepting for the `!convert` pass only for std::optional
and void casters. (The `char` caster already deferred None; this just
extends that behaviour to other casters).
Enumerations on Python 2.7 were not always implicitly converted to
integers (depending on the target size). This patch adds a __long__
conversion function (only enabled on 2.7) which fixes this issue.
The attached test case fails without this patch.
The Unicode support added in 2.1 (PR #624) inadvertently broke accepting
`bytes` as std::string/char* arguments. This restores it with a
separate path that does a plain conversion (i.e. completely bypassing
all the encoding/decoding code), but only for single-byte string types.
This commits adds base class pointers of offset base classes (i.e. due
to multiple inheritance) to `registered_instances` so that if such a
pointer is returned we properly recognize it as an existing instance.
Without this, returning a base class pointer will cast to the existing
instance if the pointer happens to coincide with the instance pointer,
but constructs a new instance (quite possibly with a segfault, if
ownership is applied) for unequal base class pointers due to multiple
inheritance.
When we are returned a base class pointer (either directly or via
shared_from_this()) we detect its runtime type (using `typeid`), then
end up essentially reinterpret_casting the pointer to the derived type.
This is invalid when the base class pointer was a non-first base, and we
end up with an invalid pointer. We could dynamic_cast to the
most-derived type, but if *that* type isn't pybind11-registered, the
resulting pointer given to the base `cast` implementation isn't necessarily valid
to be reinterpret_cast'ed back to the backup type.
This commit removes the "backup" type argument from the many-argument
`cast(...)` and instead does the derived-or-pointer type decision and
type lookup in type_caster_base, where the dynamic_cast has to be to
correctly get the derived pointer, but also has to do the type lookup to
ensure that we don't pass the wrong (derived) pointer when the backup
type (i.e. the type caster intrinsic type) pointer is needed.
Since the lookup is needed before calling the base cast(), this also
changes the input type to a detail::type_info rather than doing a
(second) lookup in cast().
This breaks up the instance management functions in class_support.h a
little bit so that other pybind11 code can use it. In particular:
- added make_new_instance() which does what pybind11_object_new does,
but also allows instance allocation without `value` allocation. This
lets `cast.h` use the same instance allocation rather than having its
own separate implementation.
- instance registration is now moved to a
`register_instance()`/deregister_instance()` pair (rather than having
individual code add or remove things from `registered_instances`
directory).
- clear_instance() does everything `pybind11_object_dealloc()` needs
except for the deallocation; this is helpful for factory construction
which needs to be able to replace the internals of an instance without
deallocating it.
- clear_instance() now also calls `dealloc` when `holder_constructed`
is true, even if `value` is false. This can happen in factory
construction when the pointer is moved from one instance to another,
but the holder itself is only copied (i.e. for a shared_ptr holder).
The holder casters assume but don't check that a `holder<type>`'s `type`
is really a `type_caster_base<type>`; this adds a static_assert to make
sure this is really the case, to turn things like
`std::shared_ptr<array>` into a compilation failure.
Fixes#785
When make_tuple fails (for example, when print() is called with a
non-convertible argument, as in #778) the error message a less helpful
than it could be:
make_tuple(): unable to convert arguments of types 'std::tuple<type1, type2>' to Python object
There is no actual std::tuple involved (only a parameter pack and a
Python tuple), but it also doesn't immediately reveal which type caused
the problem.
This commit changes the debugging mode output to show just the
problematic type:
make_tuple(): unable to convert argument of type 'type2' to Python object
Instead of a segfault. Fixes#751.
This covers the case of loading a custom holder from a default-holder
instance. Attempting to load one custom holder from a different custom
holder (i.e. not `std::unique_ptr`) yields undefined behavior, just as
#588 established for inheritance.
Some versions of Python 2.7 reportedly (#713) have issues with
PyUnicode_Decode being passed the encoding string, so just skip it
entirely by calling the PyUnicode_DecodeUTF* function directly. This
will also be slightly more efficient by avoiding having to check the
encoding string, and (for python 2) going through the unicode class's
decode (python 3 fast-tracks this for all utf-{8,16,32} encodings;
python 2 only fast-tracked for the exact string "utf-8", which we
weren't passing anyway (we had "utf8")).
This doesn't work for PyPy, however: its `PyUnicode_DecodeUTF{8,16,32}`
appear rather broken: the UTF8 one segfaults, while the 16/32 require
recasting into a non-const `char *` (and might segfault; I didn't get
far enough to find out). Just avoid the whole thing by keeping the
encoding-passed-as-string version for PyPy, which seems to work
reliably.
Commit 11a337f1 added major and minor python version
checking to cast.h but does not use the macros defined
via the Python.h inclusion. This may be due to an
intention to use the variables defined by the cmake
module FindPythonInterpreter, but nothing in the
pybind11 repo does anything to convert the cmake
variables to preprocessor defines.
Eigen::Ref objects, when returned, are almost always returned as
rvalues; what's important is the data they reference, not the outer
shell, and so we want to be able to use `::copy`,
`::reference_internal`, etc. to refer to the data the Eigen::Ref
references (in the following commits), rather than the Eigen::Ref
instance itself.
This moves the policy override into a struct so that code that wants to
avoid it (or wants to provide some other Return-type-conditional
override) can create a specialization of
return_value_policy_override<Return> in order to override the override.
This lets an Eigen::Ref-returning function be bound with `rvp::copy`,
for example, to specify that the data should be copied into a new numpy
array rather than referenced, or `rvp::reference_internal` to indicate
that it should be referenced, but a keep-alive used (actually, we used
the array's `base` rather than a py::keep_alive in such a case, but it
accomplishes the same thing).
* Make string conversion stricter
The string conversion logic added in PR #624 for all std::basic_strings
was derived from the old std::wstring logic, but that was underused and
turns out to have had a bug in accepting almost anything convertible to
unicode, while the previous std::string logic was much stricter. This
restores the previous std::string logic by only allowing actual unicode
or string types.
Fixes#685.
* Added missing 'requires numpy' decorator
(I forgot that the change to a global decorator here is in the
not-yet-merged Eigen PR)
In order to fully satisfy Python's inheritance type layout requirements,
all types should have a common 'solid' base. A solid base is one which
has the same instance size as the derived type (not counting the space
required for the optional `dict_ptr` and `weakrefs_ptr`). Thus, `object`
does not qualify as a solid base for pybind11 types and this can lead to
issues with multiple inheritance.
To get around this, new base types are created: one per unique instance
size. There is going to be very few of these bases. They ensure Python's
MRO checks will pass when multiple bases are involved.
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.
* Propagate unicode conversion failure
If returning a std::string with invalid utf-8 data, we currently fail
with an uninformative TypeError instead of propagating the
UnicodeDecodeError that Python sets on failure.
* Add support for u16/u32strings and literals
This adds support for wchar{16,32}_t character literals and the
associated std::u{16,32}string types. It also folds the
character/string conversion into a single type_caster template, since
the type casters for string and wstring were mostly the same anyway.
* Added too-long and too-big character conversion errors
With this commit, when casting to a single character, as opposed to a
C-style string, we make sure the input wasn't a multi-character string
or a single character with codepoint too large for the character type.
This also changes the character cast op to CharT instead of CharT& (we
need to be able to return a temporary decoded char value, but also
because there's little gained by bothering with an lvalue return here).
Finally it changes the char caster to 'has-a-string-caster' instead of
'is-a-string-caster' because, with the cast_op change above, there's
nothing at all gained from inheritance. This also lets us remove the
`success` from the string caster (which was only there for the char
caster) into the char caster itself. (I also renamed it to 'none' and
inverted its value to better reflect its purpose). The None -> nullptr
loading also now takes place only under a `convert = true` load pass.
Although it's unlikely that a function taking a char also has overloads
that can take a None, it seems marginally more correct to treat it as a
conversion.
This commit simplifies the size assumptions about character sizes with
static_asserts to back them up.
* Avoid C-style const casts
Replace C-style casts that discard `const` with `const_cast` (and, where
necessary, `reinterpret_cast` as well).
* Warn about C-style const-discarding casts
Change pybind11_enable_warnings to also enable `-Wcast-qual` (warn if a
C-style cast discards `const`) by default. The previous commit should
have gotten rid of all of these (at least, all the ones that tripped in
my build, which included the tests), and this should discourage more
from newly appearing.
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.
Arithmetic and complex casters now only do a converting cast when
`convert=true`; previously they would convert always (e.g. when passing
an int to a float-accepting function, or a float to complex-accepting
function).
This cleans up the previous commit slightly by further reducing the
function call arguments to a single struct (containing the
function_record, arguments vector, and parent).
Although this doesn't currently change anything, it does allow for
future functionality to have a place for precalls to store temporary
objects that need to be destroyed after a function call (whether or not
the call succeeds).
As a concrete example, with this change #625 could be easily implemented
(I think) by adding a std::unique_ptr<gil_scoped_release> member to the
`function_call` struct with a precall that actually constructs it.
Without this, the precall can't do that: the postcall won't be invoked
if the call throws an exception.
This doesn't seems to affect the .so size noticeably (either way).
This commit rewrites the function dispatcher code to support mixing
regular arguments with py::args/py::kwargs arguments. It also
simplifies the argument loader noticeably as it no longer has to worry
about args/kwargs: all of that is now sorted out in the dispatcher,
which now simply appends a tuple/dict if the function takes
py::args/py::kwargs, then passes all the arguments in a vector.
When the argument loader hit a py::args or py::kwargs, it doesn't do
anything special: it just calls the appropriate type_caster just like it
does for any other argument (thus removing the previous special cases
for args/kwargs).
Switching to passing arguments in a single std::vector instead of a pair
of tuples also makes things simpler, both in the dispatch and the
argument_loader: since this argument list is strictly pybind-internal
(i.e. it never goes to Python) we have no particular reason to use a
Python tuple here.
Some (intentional) restrictions:
- you may not bind a function that has args/kwargs somewhere other than
the end (this somewhat matches Python, and keeps the dispatch code a
little cleaner by being able to not worry about where to inject the
args/kwargs in the argument list).
- If you specify an argument both positionally and via a keyword
argument, you get a TypeError alerting you to this (as you do in
Python).
* Abstract away some holder functionality (resolve#585)
Custom holder types which don't have `.get()` can select the correct
function to call by specializing `holder_traits`.
* Add support for move-only holders (fix#605)
* Clarify PYBIND11_NUMPY_DTYPE documentation
The current documentation and example reads as though
PYBIND11_NUMPY_DTYPE is a declarative macro along the same lines as
PYBIND11_DECLARE_HOLDER_TYPE, but it isn't. The changes the
documentation and docs example to make it clear that you need to "call"
the macro.
* Add satisfies_{all,any,none}_of<T, Preds>
`satisfies_all_of<T, Pred1, Pred2, Pred3>` is a nice legibility-enhanced
shortcut for `is_all<Pred1<T>, Pred2<T>, Pred3<T>>`.
* Give better error message for non-POD dtype attempts
If you try to use a non-POD data type, you get difficult-to-interpret
compilation errors (about ::name() not being a member of an internal
pybind11 struct, among others), for which isn't at all obvious what the
problem is.
This adds a static_assert for such cases.
It also changes the base case from an empty struct to the is_pod_struct
case by no longer using `enable_if<is_pod_struct>` but instead using a
static_assert: thus specializations avoid the base class, POD types
work, and non-POD types (and unimplemented POD types like std::array)
get a more informative static_assert failure.
* Prefix macros with PYBIND11_
numpy.h uses unprefixed macros, which seems undesirable. This prefixes
them with PYBIND11_ to match all the other macros in numpy.h (and
elsewhere).
* Add long double support
This adds long double and std::complex<long double> support for numpy
arrays.
This allows some simplification of the code used to generate format
descriptors; the new code uses fewer macros, instead putting the code as
different templated options; the template conditions end up simpler with
this because we are now supporting all basic C++ arithmetic types (and
so can use is_arithmetic instead of is_integral + multiple
different specializations).
In addition to testing that it is indeed working in the test script, it
also adds various offset and size calculations there, which
fixes the test failures under x86 compilations.
* Make 'any' the default markup role for Sphinx docs
* Automate generation of reference docs with doxygen and breathe
* Improve reference docs coverage
This commit includes modifications that are needed to get pybind11 to work with PyPy. The full test suite compiles and runs except for a last few functions that are commented out (due to problems in PyPy that were reported on the PyPy bugtracker).
Two somewhat intrusive changes were needed to make it possible: two new tags ``py::buffer_protocol()`` and ``py::metaclass()`` must now be specified to the ``class_`` constructor if the class uses the buffer protocol and/or requires a metaclass (e.g. for static properties).
Note that this is only for the PyPy version based on Python 2.7 for now. When the PyPy 3.x has caught up in terms of cpyext compliance, a PyPy 3.x patch will follow.
This replaces the current `all_of_t<Pred, Ts...>` with `all_of<Ts...>`,
with previous use of `all_of_t<Pred, Ts...>` becoming
`all_of<Pred<Ts>...>` (and similarly for `any_of_t`). It also adds a
`none_of<Ts...>`, a shortcut for `negation<any_of<Ts...>>`.
This allows `all_of` and `any_of` to be used a bit more flexible, e.g.
in cases where several predicates need to be tested for the same type
instead of the same predicate for multiple types.
This commit replaces the implementation with a more efficient version
for non-MSVC. For MSVC, this changes the workaround to use the
built-in, recursive std::conjunction/std::disjunction instead.
This also removes the `count_t` since `any_of_t` and `all_of_t` were the
only things using it.
This commit also rearranges some of the future std imports to use actual
`std` implementations for C++14/17 features when under the appropriate
compiler mode, as we were already doing for a few things (like
index_sequence). Most of these aren't saving much (the implementation
for enable_if_t, for example, is trivial), but I think it makes the
intention of the code instantly clear. It also enables MSVC's native
std::index_sequence support.
Since the argument loader split off from the tuple converter, it is
never called with a `convert` argument set to anything but true. This
removes the argument entirely, passing a literal `true` from within
`argument_loader` to the individual value casters.
This adds automatic casting when assigning to python types like dict,
list, and attributes. Instead of:
dict["key"] = py::cast(val);
m.attr("foo") = py::cast(true);
list.append(py::cast(42));
you can now simply write:
dict["key"] = val;
m.attr("foo") = true;
list.append(42);
Casts needing extra parameters (e.g. for a non-default rvp) still
require the py::cast() call. set::add() is also supported.
All usage is channeled through a SFINAE implementation which either just returns or casts.
Combined non-converting handle and autocasting template methods via a
helper method that either just returns (handle) or casts (C++ type).
Newer standard libraries use compiler intrinsics for std::index_sequence
which makes it ‘free’. This prevents hitting instantiation limits for
recursive templates (-ftemplate-depth).
This is needed in order to allow the tuple caster to accept any sequence
while keeping the argument loader fast. There is also very little overlap
between the two classes which makes the separation clean. It’s also good
practice not to have completely new functionality in a specialization.
Using a complicated declval here was pointlessly complicated: we
already know the type, because that's what cast_op_type<T> is in the
first place. (The declval also broke MSVC).
This adds a `detail::cast_op<T>(caster)` function which handles the
rather verbose:
caster.operator typename CasterType::template cast_op_type<T>()
which allows various places to use the shorter and clearer:
cast_op<T>(caster)
instead of the full verbose cast operator invocation.
Fixes#509.
The move policy was already set for rvalues in PR #473, but this only
applied to directly cast user-defined types. The problem is that STL
containers cast values indirectly and the rvalue information is lost.
Therefore the move policy was not set correctly. This commit fixes it.
This also makes an additional adjustment to remove the `copy` policy
exception: rvalues now always use the `move` policy. This is also safe
for copy-only rvalues because the `move` policy has an internal fallback
to copying.
The pytype converting constructors are convenient and safe for user
code, but for library internals the additional type checks and possible
conversions are sometimes not desired. `reinterpret_borrow<T>()` and
`reinterpret_steal<T>()` serve as the low-level unsafe counterparts
of `cast<T>()`.
This deprecates the `object(handle, bool)` constructor.
Renamed `borrowed` parameter to `is_borrowed` to avoid shadowing
warnings on MSVC.
* Deprecate the `py::object::str()` member function since `py::str(obj)`
is now equivalent and preferred
* Make `py::repr()` a free function
* Make sure obj.cast<T>() works as expected when T is a Python type
`obj.cast<T>()` should be the same as `T(obj)`, i.e. it should convert
the given object to a different Python type. However, `obj.cast<T>()`
usually calls `type_caster::load()` which only checks the type without
doing any actual conversion. That causes a very unexpected `cast_error`.
This commit makes it so that `obj.cast<T>()` and `T(obj)` are the same
when T is a Python type.
* Simplify pytypes converting constructor implementation
It's not necessary to maintain a full set of converting constructors
and assignment operators + const& and &&. A single converting const&
constructor will work and there is no impact on binary size. On the
other hand, the conversion functions can be significantly simplified.
Allows checking the Python types before creating an object instead of
after. For example:
```c++
auto l = list(ptr, true);
if (l.check())
// ...
```
The above is replaced with:
```c++
if (isinstance<list>(ptr)) {
auto l = reinterpret_borrow(ptr);
// ...
}
```
This deprecates `py::object::check()`. `py::isinstance()` covers the
same use case, but it can also check for user-defined types:
```c++
class Pet { ... };
py::class_<Pet>(...);
m.def("is_pet", [](py::object obj) {
return py::isinstance<Pet>(obj); // works as expected
});
```
This commit includes the following changes:
* Don't provide make_copy_constructor for non-copyable container
make_copy_constructor currently fails for various stl containers (e.g.
std::vector, std::unordered_map, std::deque, etc.) when the container's
value type (e.g. the "T" or the std::pair<K,T> for a map) is
non-copyable. This adds an override that, for types that look like
containers, also requires that the value_type be copyable.
* stl_bind.h: make bind_{vector,map} work for non-copy-constructible types
Most stl_bind modifiers require copying, so if the type isn't copy
constructible, we provide a read-only interface instead.
In practice, this means that if the type is non-copyable, it will be,
for all intents and purposes, read-only from the Python side (but
currently it simply fails to compile with such a container).
It is still possible for the caller to provide an interface manually
(by defining methods on the returned class_ object), but this isn't
something stl_bind can handle because the C++ code to construct values
is going to be highly dependent on the container value_type.
* stl_bind: copy only for arithmetic value types
For non-primitive types, we may well be copying some complex type, when
returning by reference is more appropriate. This commit returns by
internal reference for all but basic arithmetic types.
* Return by reference whenever possible
Only if we definitely can't--i.e. std::vector<bool>--because v[i]
returns something that isn't a T& do we copy; for everything else, we
return by reference.
For the map case, we can always return by reference (at least for the
default stl map/unordered_map).
* Make reference(_internal) the default return value policy for properties
Before this, all `def_property*` functions used `automatic` as their
default return value policy. This commit makes it so that:
* Non-static properties use `reference_interal` by default, thus
matching `def_readonly` and `def_readwrite`.
* Static properties use `reference` by default, thus matching
`def_readonly_static` and `def_readwrite_static`.
In case `cpp_function` is passed to any `def_property*`, its policy will
be used instead of any defaults. User-defined arguments in `extras`
still have top priority and will override both the default policies and
the ones from `cpp_function`.
Resolves#436.
* Almost always use return_value_policy::move for rvalues
For functions which return rvalues or rvalue references, the only viable
return value policies are `copy` and `move`. `reference(_internal)` and
`take_ownership` would take the address of a temporary which is always
an error.
This commit prevents possible user errors by overriding the bad rvalue
policies with `move`. Besides `move`, only `copy` is allowed, and only
if it's explicitly selected by the user.
This is also a necessary safety feature to support the new default
return value policies for properties: `reference(_internal)`.
The current integer caster was unnecessarily strict and rejected
various kinds of NumPy integer types when calling C++ functions
expecting normal integers. This relaxes the current behavior.
type_caster_generic::cast(): The values of
wrapper->value
wrapper->owned
are incorrect in the case that a return value policy of 'copy' is
requested but there is no copy-constructor. (Similarly 'move'.) In
particular, if the source object is a static instance, the destructor of
the 'object' 'inst' leads to class_::dealloc() which incorrectly
attempts to 'delete' the static instance.
This commit re-arranges the code to be clearer as to what the values of
'value' and 'owned' should be in the various cases. Behaviour is
different to previous code only in two situations:
policy = copy but no copy-ctor: Old code leaves 'value = src, owned =
true', which leads to trouble. New code leaves 'value = nullptr, owned
= false', which is correct.
policy = move but no move- or copy-ctor: old code leaves 'value = src,
owned = true', which leads to trouble. New code leaves 'value =
nullptr, owned = false', which is correct.
With this there is no more need for manual user declarations like
`PYBIND11_DECLARE_HOLDER_TYPE(T, std::shared_ptr<T>)`. Existing ones
will still compile without error -- they will just be ignored silently.
Resolves#446.
We have various classes that have non-explicit constructors that accept
a single argument, which is implicitly making them implicitly
convertible from the argument. In a few cases, this is desirable (e.g.
implicit conversion of std::string to py::str, or conversion of double
to py::float_); in many others, however, it is unintended (e.g. implicit
conversion of size_t to some pre-declared py::array_t<T> type).
This disables most of the unwanted implicit conversions by marking them
`explicit`, and comments the ones that are deliberately left implicit.
This fixes an issue that can arise when forwarding (*args, **kwargs)
captured from a pybind11-bound function call to another Python function.
When the initial function call includes no keyword arguments, the
py::kwargs field is set to nullptr and causes a crash later on.
This also adds the `hasattr` and `getattr` functions which are needed
with the new attribute behavior. The new functions behave exactly like
their Python counterparts.
Similarly `object` gets a `contains` method which calls `__contains__`,
i.e. it's the same as the `in` keyword in Python.
