cargo fmt and cargo clippy

code/ch02-03/object/src/ipc/channel.rs

@@ -55,7 +55,7 @@ impl Channel {
     /// Read a packet from the channel if check is ok, otherwise the msg will keep.
     pub fn read(&self) -> ZxResult<T> {
         let mut recv_queue = self.recv_queue.lock();
-        if let Some(_) = recv_queue.front() {
+        if recv_queue.front().is_some() {
             let msg = recv_queue.pop_front().unwrap();
             return Ok(msg);
         }

code/ch03-02/object/src/ipc/channel.rs

@@ -55,7 +55,7 @@ impl Channel {
     /// Read a packet from the channel if check is ok, otherwise the msg will keep.
     pub fn read(&self) -> ZxResult<T> {
         let mut recv_queue = self.recv_queue.lock();
-        if let Some(_) = recv_queue.front() {
+        if recv_queue.front().is_some() {
             let msg = recv_queue.pop_front().unwrap();
             return Ok(msg);
         }

code/ch03-04/object/src/ipc/channel.rs

@@ -55,7 +55,7 @@ impl Channel {
     /// Read a packet from the channel if check is ok, otherwise the msg will keep.
     pub fn read(&self) -> ZxResult<T> {
         let mut recv_queue = self.recv_queue.lock();
-        if let Some(_) = recv_queue.front() {
+        if recv_queue.front().is_some() {
             let msg = recv_queue.pop_front().unwrap();
             return Ok(msg);
         }

code/ch03-04/object/src/vm/vmar.rs

@@ -277,8 +277,7 @@ impl VmAddressRegion {
         let length = inner.mappings.iter().fold(0, |acc, map| {
             acc + end_addr
                 .min(map.end_addr())
-                .checked_sub(addr.max(map.addr()))
-                .unwrap_or(0)
+                .saturating_sub(addr.max(map.addr()))
         });
         if length != len {
             return Err(ZxError::NOT_FOUND);

code/ch04-01/zircon-loader/src/lib.rs

@@ -10,16 +10,9 @@ extern crate log;
 use {
     alloc::{boxed::Box, sync::Arc, vec::Vec},
     core::{future::Future, pin::Pin},
-    xmas_elf::ElfFile,
-    zircon_object::{
-        dev::*,
-        ipc::*, 
-        object::*, 
-        task::*, 
-        util::elf_loader::*, 
-        vm::*,
-    },
     kernel_hal::MMUFlags,
+    xmas_elf::ElfFile,
+    zircon_object::{dev::*, ipc::*, object::*, task::*, util::elf_loader::*, vm::*},
 };
 
 mod kcounter;

code/ch04-01/zircon-object/src/ipc/channel.rs

@@ -56,7 +56,7 @@ impl Channel {
     /// Read a packet from the channel if check is ok, otherwise the msg will keep.
     pub fn read(&self) -> ZxResult<T> {
         let mut recv_queue = self.recv_queue.lock();
-        if let Some(_) = recv_queue.front() {
+        if recv_queue.front().is_some() {
             let msg = recv_queue.pop_front().unwrap();
             return Ok(msg);
         }

code/ch04-01/zircon-object/src/lib.rs

@@ -13,12 +13,12 @@ extern crate std;
 #[macro_use]
 extern crate log;
 
+pub mod dev;
 pub mod error;
 pub mod ipc;
 pub mod object;
 pub mod task;
 pub mod util;
 pub mod vm;
-pub mod dev;
 
 pub use self::error::*;

code/ch04-01/zircon-object/src/vm/vmar.rs

@@ -277,8 +277,7 @@ impl VmAddressRegion {
         let length = inner.mappings.iter().fold(0, |acc, map| {
             acc + end_addr
                 .min(map.end_addr())
-                .checked_sub(addr.max(map.addr()))
-                .unwrap_or(0)
+                .saturating_sub(addr.max(map.addr()))
         });
         if length != len {
             return Err(ZxError::NOT_FOUND);