[Cython] Supporting cython.operator in C

The following code cimport cython.operator cdef long foo(long x, long y): return cython.operator.comma(x, y) gives AttributeError: 'CBinopNode' object has no attribute 'analyse_c_operation' Is there any fundamental reason why such operators are only implemented for C++ and not pure C? What would be needed to support such operators in C? Jeroen.