more 'let else' simplification

capnp-rpc/src/rpc.rs

@@ -206,36 +206,32 @@ impl<VatId> QuestionRef<VatId> {
 impl<VatId> Drop for QuestionRef<VatId> {
  fn drop(&mut self) {
  let mut questions = self.connection_state.questions.borrow_mut();
- match &mut questions.slots[self.id as usize] {
- Some(q) => {
- if let Ok(ref mut c) = *self.connection_state.connection.borrow_mut() {
- let mut message = c.new_outgoing_message(5);
- {
- let root: message::Builder = message.get_body().unwrap().init_as();
- let mut builder = root.init_finish();
- builder.set_question_id(self.id);
-
- // If we're still awaiting a return, then this request is being
- // canceled, and we're going to ignore any capabilities in the return
- // message, so set releaseResultCaps true. If we already received the
- // return, then we've already built local proxies for the caps and will
- // send Release messages when those are destroyed.
- builder.set_release_result_caps(q.is_awaiting_return);
- }
- let _ = message.send();
- }
+ let Some(q) = &mut questions.slots[self.id as usize] else {
+ unreachable!()
+ };
+ if let Ok(ref mut c) = *self.connection_state.connection.borrow_mut() {
+ let mut message = c.new_outgoing_message(5);
+ {
+ let root: message::Builder = message.get_body().unwrap().init_as();
+ let mut builder = root.init_finish();
+ builder.set_question_id(self.id);
 
- if q.is_awaiting_return {
- // Still waiting for return, so just remove the QuestionRef pointer from the table.
- q.self_ref = None;
- } else {
- // Call has already returned, so we can now remove it from the table.
- questions.erase(self.id)
- }
- }
- None => {
- unreachable!()
+ // If we're still awaiting a return, then this request is being
+ // canceled, and we're going to ignore any capabilities in the return
+ // message, so set releaseResultCaps true. If we already received the
+ // return, then we've already built local proxies for the caps and will
+ // send Release messages when those are destroyed.
+ builder.set_release_result_caps(q.is_awaiting_return);
  }
+ let _ = message.send();
+ }
+
+ if q.is_awaiting_return {
+ // Still waiting for return, so just remove the QuestionRef pointer from the table.
+ q.self_ref = None;
+ } else {
+ // Call has already returned, so we can now remove it from the table.
+ questions.erase(self.id)
  }
  }
 }
@@ -554,27 +550,25 @@ impl<VatId> ConnectionState<VatId> {
 
  let connection = mem::replace(&mut *self.connection.borrow_mut(), Err(error.clone()));
 
- match connection {
- Ok(mut c) => {
- let promise = c.shutdown(Err(error)).then(|r| match r {
- Ok(()) => Promise::ok(()),
- Err(e) => {
- if e.kind != ::capnp::ErrorKind::Disconnected {
- // Don't report disconnects as an error.
- Promise::err(e)
- } else {
- Promise::ok(())
- }
- }
- });
- match self.disconnect_fulfiller.borrow_mut().take() {
- None => unreachable!(),
- Some(fulfiller) => {
- let _ = fulfiller.send(Promise::from_future(promise.attach(c)));
- }
+ let Ok(mut c) = connection else {
+ unreachable!()
+ };
+ let promise = c.shutdown(Err(error)).then(|r| match r {
+ Ok(()) => Promise::ok(()),
+ Err(e) => {
+ if e.kind != ::capnp::ErrorKind::Disconnected {
+ // Don't report disconnects as an error.
+ Promise::err(e)
+ } else {
+ Promise::ok(())
  }
  }
- Err(_) => unreachable!(),
+ });
+ match self.disconnect_fulfiller.borrow_mut().take() {
+ None => unreachable!(),
+ Some(fulfiller) => {
+ let _ = fulfiller.send(Promise::from_future(promise.attach(c)));
+ }
  }
  }
 
@@ -1398,14 +1392,10 @@ impl<VatId> ConnectionState<VatId> {
  if contains_key {
  // We've already seen and exported this capability before. Just up the refcount.
  let export_id = state.exports_by_cap.borrow()[&ptr];
- match state.exports.borrow_mut().find(export_id) {
- None => unreachable!(),
- Some(exp) => {
- descriptor.set_sender_hosted(export_id);
- exp.refcount += 1;
- Ok(Some(export_id))
- }
- }
+ descriptor.set_sender_hosted(export_id);
+ // Should never fail because exports_by_cap should match exports.
+ state.exports.borrow_mut().find(export_id).unwrap().refcount += 1;
+ Ok(Some(export_id))
  } else {
  // This is the first time we've seen this capability.