Jason Rhinelander e45c211497 Support multiple inheritance from python ... 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.		2017-06-12 09:56:55 -03:00
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pybind11	Support multiple inheritance from python	2017-06-12 09:56:55 -03:00