Auto merge of #67310 - Centril:rollup-22jiyow, r=Centril

Rollup of 6 pull requests

Successful merges:

 - #67255 (Remove i686-unknown-dragonfly target)
 - #67267 (Fix signature of `__wasilibc_find_relpath`)
 - #67282 (Fix example code of OpenOptions::open)
 - #67289 (Do not ICE on unnamed future)
 - #67300 (Restore original implementation of Vec::retain)
 - #67305 (Doc typo)

Failed merges:

r? @ghost

1 files changed, 16 insertions, 1 deletions

diff --git a/src/liballoc/vec.rs b/src/liballoc/vec.rs
index 52b45b0b8fe..2ad4e22884e 100644
--- a/src/liballoc/vec.rs
+++ b/src/liballoc/vec.rs
@@ -1079,7 +1079,22 @@ impl<T> Vec<T> {
     pub fn retain<F>(&mut self, mut f: F)
         where F: FnMut(&T) -> bool
     {
-        self.drain_filter(|x| !f(x));
+        let len = self.len();
+        let mut del = 0;
+        {
+            let v = &mut **self;
+
+            for i in 0..len {
+                if !f(&v[i]) {
+                    del += 1;
+                } else if del > 0 {
+                    v.swap(i - del, i);
+                }
+            }
+        }
+        if del > 0 {
+            self.truncate(len - del);
+        }
     }
 
     /// Removes all but the first of consecutive elements in the vector that resolve to the same