pub type PFN_cusparseSDDMM_preprocess = unsafe extern "C" fn(handle: cusparseHandle_t, op_a: cusparseOperation_t, op_b: cusparseOperation_t, alpha: *const c_void, mat_a: cusparseDnMatDescr_t, mat_b: cusparseDnMatDescr_t, beta: *const c_void, mat_c: cusparseSpMatDescr_t, compute_type: cudaDataType, alg: cusparseSDDMMAlg_t, external_buffer: *mut c_void) -> cusparseStatus_t;