2024 edition migration seems overly eager to rewrite every if let into match

[djc]

I tried running cargo +nightly fix --edition against Quinn. It seems to rewrite a lot of instances of if let to match, without seemingly much explanation or discrimination. This makes the code harder to read/less concise in many cases. Is this really necessary for all these cases? Could it somehow be made to be more precise/discriminate?

@@ -1254,8 +1284,11 @@ impl fmt::Debug for State {
 }
 
 fn wake_stream(stream_id: StreamId, wakers: &mut FxHashMap<StreamId, Waker>) {
-    if let Some(waker) = wakers.remove(&stream_id) {
-        waker.wake();
+    match wakers.remove(&stream_id) {
+        Some(waker) => {
+            waker.wake();
+        }
+        _ => {}
     }
 }
 

@@ -95,8 +95,11 @@ impl Incoming {
 impl Drop for Incoming {
     fn drop(&mut self) {
         // Implicit reject, similar to Connection's implicit close
-        if let Some(state) = self.0.take() {
-            state.endpoint.refuse(state.inner);
+        match self.0.take() {
+            Some(state) => {
+                state.endpoint.refuse(state.inner);
+            }
+            _ => {}
         }
     }
 }

[jieyouxu]

cc @dingxiangfei2009 @traviscross (FYI)

[zh-jq-b]

As you can see in #133529, cargo fix --edition --workspace changed 282 files (1438 insertions, 1451 deletions), most of them are unneeded if let -> match, while manual fix only need 19 files changed, 48 insertions(+), 37 deletions(-).

[traviscross]

Thanks for the report. The essence of this probably duplicates:

• false positive for if-let-rescope where if let statements without else are also linted #133167

So let's track this there.