diff --git a/examples/beep.rs b/examples/beep.rs
index e0266aa79..7d3b23d88 100644
--- a/examples/beep.rs
+++ b/examples/beep.rs
@@ -1,4 +1,3 @@
-use anyhow;
 use clap::Parser;
 use cpal::{
     traits::{DeviceTrait, HostTrait, StreamTrait},
diff --git a/src/host/coreaudio/macos/mod.rs b/src/host/coreaudio/macos/mod.rs
index 9a14ab269..55cd988ca 100644
--- a/src/host/coreaudio/macos/mod.rs
+++ b/src/host/coreaudio/macos/mod.rs
@@ -33,6 +33,7 @@ use std::fmt;
 use std::mem;
 use std::os::raw::c_char;
 use std::ptr::null;
+use std::rc::Rc;
 use std::slice;
 use std::sync::mpsc::{channel, RecvTimeoutError};
 use std::sync::{Arc, Mutex};
@@ -306,7 +307,7 @@ impl Device {
                     channels: n_channels as ChannelCount,
                     min_sample_rate: SampleRate(range.mMinimum as _),
                     max_sample_rate: SampleRate(range.mMaximum as _),
-                    buffer_size: buffer_size.clone(),
+                    buffer_size,
                     sample_format,
                 };
                 fmts.push(fmt);
@@ -568,7 +569,7 @@ impl Device {
         let sample_rate = config.sample_rate;
         type Args = render_callback::Args<data::Raw>;
         audio_unit.set_input_callback(move |args: Args| unsafe {
-            let ptr = (*args.data.data).mBuffers.as_ptr() as *const AudioBuffer;
+            let ptr = (*args.data.data).mBuffers.as_ptr();
             let len = (*args.data.data).mNumberBuffers as usize;
             let buffers: &[AudioBuffer] = slice::from_raw_parts(ptr, len);
 
@@ -580,7 +581,7 @@ impl Device {
             } = buffers[0];
 
             let data = data as *mut ();
-            let len = (data_byte_size as usize / bytes_per_channel) as usize;
+            let len = data_byte_size as usize / bytes_per_channel;
             let data = Data::from_parts(data, len, sample_format);
 
             // TODO: Need a better way to get delay, for now we assume a double-buffer offset.
@@ -685,7 +686,7 @@ impl Device {
             } = (*args.data.data).mBuffers[0];
 
             let data = data as *mut ();
-            let len = (data_byte_size as usize / bytes_per_channel) as usize;
+            let len = data_byte_size as usize / bytes_per_channel;
             let mut data = Data::from_parts(data, len, sample_format);
 
             let callback = match host_time_to_stream_instant(args.time_stamp.mHostTime) {
diff --git a/src/host/coreaudio/macos/property_listener.rs b/src/host/coreaudio/macos/property_listener.rs
index 392d2c8dc..cbe8ec2c2 100644
--- a/src/host/coreaudio/macos/property_listener.rs
+++ b/src/host/coreaudio/macos/property_listener.rs
@@ -8,7 +8,7 @@ use crate::BuildStreamError;
 
 /// A double-indirection to be able to pass a closure (a fat pointer)
 /// via a single c_void.
-struct PropertyListenerCallbackWrapper(Box<dyn FnMut() -> ()>);
+struct PropertyListenerCallbackWrapper(Box<dyn FnMut()>);
 
 /// Maintain an audio object property listener.
 /// The listener will be removed when this type is dropped.
@@ -21,7 +21,7 @@ pub struct AudioObjectPropertyListener {
 
 impl AudioObjectPropertyListener {
     /// Attach the provided callback as a audio object property listener.
-    pub fn new<F: FnMut() -> () + 'static>(
+    pub fn new<F: FnMut() + 'static>(
         audio_object_id: AudioObjectID,
         property_address: AudioObjectPropertyAddress,
         callback: F,
diff --git a/src/host/coreaudio/mod.rs b/src/host/coreaudio/mod.rs
index f1b47f82c..f82f5da5c 100644
--- a/src/host/coreaudio/mod.rs
+++ b/src/host/coreaudio/mod.rs
@@ -52,8 +52,8 @@ fn asbd_from_config(
     let frames_per_packet = 1;
     let bytes_per_packet = frames_per_packet * bytes_per_frame;
     let format_flags = match sample_format {
-        SampleFormat::F32 => (kAudioFormatFlagIsFloat | kAudioFormatFlagIsPacked) as u32,
-        _ => kAudioFormatFlagIsPacked as u32,
+        SampleFormat::F32 => kAudioFormatFlagIsFloat | kAudioFormatFlagIsPacked,
+        _ => kAudioFormatFlagIsPacked,
     };
     AudioStreamBasicDescription {
         mBitsPerChannel: bits_per_channel as _,
diff --git a/src/lib.rs b/src/lib.rs
index 3b6683c5e..74405a4a2 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -742,7 +742,7 @@ impl SupportedStreamConfigRange {
 
 #[test]
 fn test_cmp_default_heuristics() {
-    let mut formats = vec![
+    let mut formats = [
         SupportedStreamConfigRange {
             buffer_size: SupportedBufferSize::Range { min: 256, max: 512 },
             channels: 2,