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.
libc++ 3.8 (and possibly others--including the derived version on OS X),
doesn't define the macro, but does support std::experimental::optional.
This removes the extra macro check and just assumes the header existing
is enough, which is what we do for <optional> and <variant>.
Now that #851 has removed all multiple uses of a caster, it can just use
the default-constructed value with needing a reset. This fixes two
issues:
1. With std::experimental::optional (at least under GCC 5.4), the `= {}`
would construct an instance of the optional type and then move-assign
it, which fails if the value type isn't move-assignable.
2. With older versions of Boost, the `= {}` could fail because it is
ambiguous, allowing construction of either `boost::none` or the value
type.
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.
Currently, `py::int_(1).cast<variant<double, int>>()` fills the `double`
slot of the variant. This commit switches the loader to a 2-pass scheme
in order to correctly fill the `int` slot.
The PYBIND11_CPP14 macro started out as a guard for the compile-time
path code in `descr.h`, but has since come to mean other things. This
means that while the `descr.h` check has just checked the
`PYBIND11_CPP14` macro, various other places now check `PYBIND11_CPP14
|| _MSC_VER`. This reverses that by now setting the CPP14 macro when
MSVC is trying to support C++14, but disabling the `descr.h` C++14 code
(which still fails under MSVC 2017).
The CPP17 macro also gets enabled when MSVC 2017 is compiling with
/std:c++latest (the default is /std:c++14), which enables
`std::optional` and `std::variant` support under MSVC.
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.
* Added ternary support with descr args
Current the `_<bool>(a, b)` ternary support only works for `char[]` `a`
and `b`; this commit allows it to work for `descr` `a` and `b` arguments
as well.
* Add support for std::valarray to stl.h
This abstracts the std::array into a `array_caster` which can then be
used with either std::array or std::valarray, the main difference being
that std::valarray is resizable. (It also lets the array_caster be
potentially used for other std::array-like interfaces, much as the
list_caster and map_caster currently provide).
* Small stl.h cleanups
- Remove redundant `type` typedefs
- make internal list_caster methods private
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.
stl casters were using a value cast to (Value) or (Key), but that isn't
always appropriate. This changes it to use the appropriate value
converter's cast_op_type.
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
});
```
There are now more places than just descr.h that make use of these.
The new macro isn't quite the same: the old one only tested for a
couple features, while the new one checks for the __cplusplus version
(but doesn't even try to enable C++14 for MSVC/ICC).
g++ 7 adds <optional>, but including it in C++14 mode isn't allowed
(just as including <experimental/optional> isn't allowed in C++11 mode).
(This wasn't triggered in g++-6 because it doesn't provide <optional>
yet.)
* Add type caster for std::experimental::optional
* Add tests for std::experimental::optional
* Support both <optional> / <experimental/optional>
* Mention std{::experimental,}::optional in the docs
- new pybind11::base<> attribute to indicate a subclass relationship
- unified infrastructure for parsing variadic arguments in class_ and cpp_function
- use 'handle' and 'object' more consistently everywhere
This modification taps into some newer C++14 features (if present) to
generate function signatures considerably more efficiently at compile
time rather than at run time.
With this change, pybind11 binaries are now *2.1 times* smaller compared
to the Boost.Python baseline in the benchmark. Compilation times get a
nice improvement as well.
Visual Studio 2015 unfortunately doesn't implement 'constexpr' well
enough yet to support this change and uses a runtime fallback.
Using object class to hold converted object automatically deallocates
object if an exception is thrown or scope is left before constructing
complete Python object.
Additionally added method object::release() that allows to release
ownership of python object without decreasing its reference count.
