Cython & C++: passing by reference
Found the answer to my own question. Apparently, you can pass by reference, but the function MUST be cdef'ed, not def'ed. i.e.
# somefile.pyx#distutils: language = c++from libcpp.vector cimport vectorcdef void add_one(vector[int]& vect): cdef int i n = vect.size() for i in range(<int>n): vect[i] += 1cdef vector[int] vfor i in range(100000): v.push_back(i)add_one(v)