Function ips_apply_study 

pub unsafe extern "C" fn ips_apply_study(
    patch: mem,
    study: *mut ipsstudy,
    in_: mem,
    out: *mut mem,
) -> ipserror

Apply a patch using a previously made study to avoid recreating a study.

Since ips_apply calls ips_study before applying the patch, you should use this function if you have already created a study beforehand.