are you happy clippy

src/lib.rs

@@ -159,7 +159,7 @@ impl Wal {
         // Validate the closed segments. They must be non-overlapping, and contiguous.
         closed_segments.sort_by(|a, b| a.start_index.cmp(&b.start_index));
         let mut next_start_index = closed_segments
-            .get(0)
+            .first()
             .map_or(0, |segment| segment.start_index);
         for &ClosedSegment {
             start_index,
@@ -394,7 +394,7 @@ impl Wal {
         if until
             <= self
                 .closed_segments
-                .get(0)
+                .first()
                 .map_or(0, |segment| segment.start_index)
         {
             // Do nothing, the first entry is already greater than `until`.
@@ -450,15 +450,15 @@ impl Wal {
         self.open_segment_start_index()
             - self
                 .closed_segments
-                .get(0)
+                .first()
                 .map_or(0, |segment| segment.start_index)
             + self.open_segment.segment.len() as u64
     }
 
     /// The index of the first entry.
     pub fn first_index(&self) -> u64 {
         self.closed_segments
-            .get(0)
+            .first()
             .map_or(0, |segment| segment.start_index)
     }
 
@@ -523,7 +523,7 @@ impl fmt::Debug for Wal {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         let start_index = self
             .closed_segments
-            .get(0)
+            .first()
             .map_or(0, |segment| segment.start_index);
         let end_index = self.open_segment_start_index() + self.open_segment.segment.len() as u64;
         write!(

src/segment.rs

@@ -648,6 +648,13 @@ impl Segment {
     where
         P: AsRef<Path>,
     {
+        if path.as_ref().exists() {
+            return Err(Error::new(
+                ErrorKind::AlreadyExists,
+                format!("Path {:?} already exists", path.as_ref()),
+            ));
+        }
+
         let mut other = Self::create(path, self.capacity())?;
         unsafe {
             other