Some minor clippy fixes

src/skipmap.rs

@@ -271,9 +271,9 @@ impl InnerSkipMap {
 
         // Insert new node by first replacing the previous element's next field with None and
         // assigning its value to new.next...
-        new.next = unsafe { replace(&mut (*current).next, None) };
+        new.next = unsafe { (*current).next.take() };
         // ...and then setting the previous element's next field to the new node
-        unsafe { replace(&mut (*current).next, Some(new)) };
+        unsafe { let _ = replace(&mut (*current).next, Some(new)); };
     }
     /// Runs through the skipmap and prints everything including addresses
     fn dbg_print(&self) {
@@ -287,7 +287,7 @@ impl InnerSkipMap {
                     (*current).value,
                     (*current).skips
                 );
-                if let Some(next) = (*current).skips[0].clone() {
+                if let Some(next) = (*current).skips[0] {
                     current = next;
                 } else {
                     break;

src/version.rs

@@ -179,7 +179,7 @@ impl Version {
                     let overlaps = self.overlapping_inputs(
                         level + 2,
                         start.internal_key(),
-                        &limit.internal_key(),
+                        limit.internal_key(),
                     );
                     let size = total_size(overlaps.iter());
                     if size > 10 * (2 << 20) {
@@ -195,20 +195,19 @@ impl Version {
     /// record_read_sample returns true if there is a new file to be compacted. It counts the
     /// number of files overlapping a key, and which level contains the first overlap.
     #[allow(unused_assignments)]
-    pub fn record_read_sample<'a>(&mut self, key: InternalKey<'a>) -> bool {
-        let levels = self.get_overlapping(key);
+    pub fn record_read_sample(&mut self, key: InternalKey<'_>) -> bool {
         let mut contained_in = 0;
         let mut i = 0;
         let mut first_file = None;
         let mut first_file_level = None;
-        for level in &levels {
+        self.get_overlapping(key).iter().for_each(|level| {
             if !level.is_empty() && first_file.is_none() && first_file_level.is_none() {
                 first_file = Some(level[0].clone());
                 first_file_level = Some(i);
             }
             contained_in += level.len();
             i += 1;
-        }
+        });
 
         if contained_in > 1 {
             self.update_stats(GetStats {