Cython C-array initialization

cdef int mom2calc[3]
mom2calc[:] = [1, 2, 3]

This works on raw pointers (although it isn't bounds checked then), memory views and fixed-sized arrays. It only works in one dimension, but that's often enough:

cdef int mom2calc[3][3]
mom2calc[0][:] = [1, 2, 3]
mom2calc[1][:] = [4, 5, 6]
mom2calc[2][:] = [7, 8, 9]

cdef int[3] mom2calc = [1, 2, 3]

This is how it should be done. Example of C-array initialization in Cython tests is e.g. here.