diff --git a/src/cache/check.rs b/src/cache/check.rs
index 92895e1..5f9d295 100644
--- a/src/cache/check.rs
+++ b/src/cache/check.rs
@@ -35,7 +35,7 @@ impl CheckMappingVisitor {
 
     fn seen_oblock(&self, b: u64) -> bool {
         let seen_oblocks = self.seen_oblocks.lock().unwrap();
-        return seen_oblocks.contains(&b);
+        seen_oblocks.contains(&b)
     }
 
     fn record_oblock(&self, b: u64) {
@@ -46,7 +46,7 @@ impl CheckMappingVisitor {
     // FIXME: is it possible to validate flags at an early phase?
     // e.g., move to ctor of Mapping?
     fn has_unknown_flags(&self, m: &Mapping) -> bool {
-        return (m.flags & self.allowed_flags) != 0;
+        (m.flags & self.allowed_flags) != 0
     }
 }
 
diff --git a/src/cache/dump.rs b/src/cache/dump.rs
index 566673f..fc2714a 100644
--- a/src/cache/dump.rs
+++ b/src/cache/dump.rs
@@ -23,7 +23,7 @@ struct MappingEmitter {
 impl MappingEmitter {
     pub fn new(emitter: Arc<Mutex<dyn MetadataVisitor>>) -> MappingEmitter {
         MappingEmitter {
-            emitter: emitter,
+            emitter,
         }
     }
 }
@@ -58,7 +58,7 @@ struct HintEmitter<Width> {
 impl<Width> HintEmitter<Width> {
     pub fn new(emitter: Arc<Mutex<dyn MetadataVisitor>>) -> HintEmitter<Width> {
         HintEmitter {
-            emitter: emitter,
+            emitter,
             _not_used: PhantomData,
         }
     }
diff --git a/src/cache/mapping.rs b/src/cache/mapping.rs
index 7ee8768..4919ce5 100644
--- a/src/cache/mapping.rs
+++ b/src/cache/mapping.rs
@@ -22,11 +22,11 @@ pub struct Mapping {
 
 impl Mapping {
     pub fn is_valid(&self) -> bool {
-        return (self.flags & MappingFlags::Valid as u32) != 0;
+        (self.flags & MappingFlags::Valid as u32) != 0
     }
 
     pub fn is_dirty(&self) -> bool {
-        return (self.flags & MappingFlags::Dirty as u32) != 0;
+        (self.flags & MappingFlags::Dirty as u32) != 0
     }
 }
 
diff --git a/src/pdata/array_block.rs b/src/pdata/array_block.rs
index 0cf7069..ad52bba 100644
--- a/src/pdata/array_block.rs
+++ b/src/pdata/array_block.rs
@@ -50,7 +50,7 @@ impl<V: Unpack> ArrayBlock<V> {
     }
 }
 
-fn convert_result<'a, V>(r: IResult<&'a [u8], V>) -> Result<(&'a [u8], V)> {
+fn convert_result<V>(r: IResult<&[u8], V>) -> Result<(&[u8], V)> {
     r.map_err(|_| anyhow!("parse error"))
 }