| 362                         match self.data { | 362                         match self.data { | 
| 363                             NodeOption::Branches(ref mut arc_b) => { | 363                             NodeOption::Branches(ref mut arc_b) => { | 
| 364                                 let mut container = container_arc.lock().unwrap(); | 364                                 let mut container = container_arc.lock().unwrap(); | 
| 365                                 // Safe: we just created arg_b and have a mutable exclusive | 365                                 // Safe: we just created arg_b and have a mutable exclusive | 
| 366                                 // reference to self containing it. | 366                                 // reference to self containing it. | 
|  | 367                                 #[cfg(feature = "nightly")] | 
| 367                                 unsafe { Arc::get_mut_unchecked(arc_b) } | 368                                 unsafe { Arc::get_mut_unchecked(arc_b) } | 
| 368                                     .stage_refine(domain, &mut *container); | 369                                     .stage_refine(domain, &mut *container); | 
|  | 370                                 #[cfg(not(feature = "nightly"))] | 
|  | 371                                 Arc::get_mut(arc_b).unwrap() | 
|  | 372                                     .stage_refine(domain, &mut *container); | 
|  | 373 | 
| 369                                 return Err(container) | 374                                 return Err(container) | 
| 370                             }, | 375                             }, | 
| 371                             _ => unreachable!("This cannot happen"), | 376                             _ => unreachable!("This cannot happen"), | 
| 372                         } | 377                         } | 
| 373                     } | 378                     } |