Function nros_rmw_qos_incompatibility_mask 

pub unsafe extern "C" fn nros_rmw_qos_incompatibility_mask(
    offered: rmw_qos_profile_t,
    requested: rmw_qos_profile_t,
    compatibility: *mut Type,
    clash_mask: *mut u32,
) -> rmw_ret_t

Which policies of offered (a publisher’s) and requested (a subscription’s) are incompatible, as a bitmask — no strings, so an image that only needs the verdict never links the reason table.

Argument order is upstream’s: publisher profile first.

Writes *compatibility and *clash_mask on NROS_RMW_RET_OK; NROS_RMW_RET_INVALID_ARGUMENT if either out-parameter is NULL.