Function nova_rt_task_is_done 

#[unsafe(no_mangle)]
pub unsafe extern "C-unwind" fn nova_rt_task_is_done(
    future: *mut u8,
) -> i8

Whether the task named by future’s state object has completed.

"C-unwind": see PollFn’s doc comment. Sharing one ABI across every entry point in this module means a caller never has to know which of them can panic; is_done/take_output’s internal helpers do, on an unknown task id, and so does resolving future itself (see [task_id_of]).

Safety

future must be a valid future fat pointer (see [read_future]). One this thread never spawned ends the process rather than answering.