Determine whether array represents data as unsigned 64-bit integers
Logical 1 (true) if the mxArray stores its data as unsigned 64-bit integers, and logical 0 (false) otherwise.
Use mxIsUint64 to determine whether the specified mxArray represents its real and imaginary data as 64-bit unsigned integers.
In C, calling mxIsUint64 is equivalent to calling:
mxGetClassID(pm) == mxUINT64_CLASS
In Fortran, calling mxIsUint64 is equivalent to calling:
mxGetClassName(pm) .eq. 'uint64'