Passing C++ pointer as argument into Cython function

Question

cdef extern from \"Foo.h\":
    cdef cppclass Bar:
        pass

cdef class PyClass:
    cdef Bar *bar

    def __cinit__(self, Bar *b)
        bar = b

Answer 1

As of Cython 0.21 it has been possible to declare cdef methods with the @staticmethod decorator. This allows static creator methods that take non-Python arguments:

cdef extern from "Foo.h":
    cdef cppclass Bar:
        pass

cdef class PyClass:
    cdef Bar *bar

    @staticmethod
    cdef create(Bar *bar):
        cdef PyClass pc = PyClass()
        pc.bar = bar
        return pc