Question about function parameter copy

[Robert]

Hi,

I see the following line in a cython file (.pyx):




cdef inline dtype_t _logsumexp(dtype_t[:] X) nogil:
.....

          fwdlattice[t, j] = _logsumexp(work_buffer) + framelogprob[t, j]

I find that [:] is about object copy, but I am not sure about its usage
here in a function parameter. Whether is it true that it makes a parameter
copy?
Why is it used in this way?


Thanks,