Question about C++ references

[Charanpal Dhanjal]

Hi all,

I am trying to wrap some C++ code in Cython and am having trouble with references. Here is a code snippet:

cdef extern from "mapped_matrix_ext.h":

cdef cppclass mapped_matrix_ext[T]:

mapped_matrix_ext(int, int, int)

mapped_matrix_ext[T]& add(mapped_matrix_ext[T]&)

cdef mapped_matrix_ext[double] *A = new mapped_matrix_ext[double](3, 3, 5)

cdef mapped_matrix_ext[double] *B = new mapped_matrix_ext[double](3, 3, 5)
cdef mapped_matrix_ext[double] *C

C = A.add(deref(B))

I get the error "Cannot assign type 'mapped_matrix_ext<double> &' to 'mapped_matrix_ext<double> *'" for the last line which I think means that I need to find the reference of the value returned by the add method. I wasn't able to find how to do this in the documentation however (I think it's meant to be in "Declaring/Using References" which hasn't yet been written). Could someone please help me out?

Thanks for any help,
Charanpal

[Bradley Froehle]

You have defined "add" to return a reference (mapped_matrix_ext[T]&) but are assigning the result to a pointer (mapped_matrix_ext[double]*).

[Charanpal Dhanjal]

Thanks. Sorry if this is a silly question - is there a simple way I can convert the reference into a pointer?
Charanpal