Correct the clippy::use_self lint where possible. (#114)

src/error.rs

@@ -1,3 +1,5 @@
+// Due to https://github.com/rust-lang/rust/issues/64247
+#![allow(clippy::use_self)]
 use crate::host;
 use failure::Fail;
 use std::convert::Infallible;

src/fdentry.rs

@@ -15,21 +15,21 @@ pub(crate) enum Descriptor {
 impl Descriptor {
     pub(crate) fn as_file(&self) -> Result<&OsFile> {
         match self {
-            Descriptor::OsFile(file) => Ok(file),
+            Self::OsFile(file) => Ok(file),
             _ => Err(Error::EBADF),
         }
     }
 
     pub(crate) fn as_file_mut(&mut self) -> Result<&mut OsFile> {
         match self {
-            Descriptor::OsFile(file) => Ok(file),
+            Self::OsFile(file) => Ok(file),
             _ => Err(Error::EBADF),
         }
     }
 
     pub(crate) fn is_file(&self) -> bool {
         match self {
-            Descriptor::OsFile(_) => true,
+            Self::OsFile(_) => true,
             _ => false,
         }
     }
@@ -37,7 +37,7 @@ impl Descriptor {
     #[allow(unused)]
     pub(crate) fn is_stdin(&self) -> bool {
         match self {
-            Descriptor::Stdin => true,
+            Self::Stdin => true,
             _ => false,
         }
     }
@@ -45,7 +45,7 @@ impl Descriptor {
     #[allow(unused)]
     pub(crate) fn is_stdout(&self) -> bool {
         match self {
-            Descriptor::Stdout => true,
+            Self::Stdout => true,
             _ => false,
         }
     }
@@ -53,7 +53,7 @@ impl Descriptor {
     #[allow(unused)]
     pub(crate) fn is_stderr(&self) -> bool {
         match self {
-            Descriptor::Stderr => true,
+            Self::Stderr => true,
             _ => false,
         }
     }

src/sys/unix/fdentry_impl.rs

@@ -21,10 +21,10 @@ cfg_if::cfg_if! {
 impl AsRawFd for Descriptor {
     fn as_raw_fd(&self) -> RawFd {
         match self {
-            Descriptor::OsFile(file) => file.as_raw_fd(),
+            Self::OsFile(file) => file.as_raw_fd(),
-            Descriptor::Stdin => io::stdin().as_raw_fd(),
+            Self::Stdin => io::stdin().as_raw_fd(),
-            Descriptor::Stdout => io::stdout().as_raw_fd(),
+            Self::Stdout => io::stdout().as_raw_fd(),
-            Descriptor::Stderr => io::stderr().as_raw_fd(),
+            Self::Stderr => io::stderr().as_raw_fd(),
         }
     }
 }

src/sys/windows/fdentry_impl.rs

@@ -37,10 +37,10 @@ impl DerefMut for OsFile {
 impl AsRawHandle for Descriptor {
     fn as_raw_handle(&self) -> RawHandle {
         match self {
-            Descriptor::OsFile(file) => file.as_raw_handle(),
+            Self::OsFile(file) => file.as_raw_handle(),
-            Descriptor::Stdin => io::stdin().as_raw_handle(),
+            Self::Stdin => io::stdin().as_raw_handle(),
-            Descriptor::Stdout => io::stdout().as_raw_handle(),
+            Self::Stdout => io::stdout().as_raw_handle(),
-            Descriptor::Stderr => io::stderr().as_raw_handle(),
+            Self::Stderr => io::stderr().as_raw_handle(),
         }
     }
 }
@@ -96,9 +96,7 @@ pub(crate) unsafe fn determine_type_rights<Handle: AsRawHandle>(
             )
         } else if file_type.is_disk() {
             // disk file: file, dir or disk device
-            let file = std::mem::ManuallyDrop::new(unsafe {
+            let file = std::mem::ManuallyDrop::new(File::from_raw_handle(handle.as_raw_handle()));
-                File::from_raw_handle(handle.as_raw_handle())
-            });
             let meta = file.metadata().map_err(|_| Error::EINVAL)?;
             if meta.is_dir() {
                 (

src/sys/windows/hostcalls_impl/fs_helpers.rs

@@ -4,7 +4,6 @@ use crate::{host, Error, Result};
 use std::ffi::{OsStr, OsString};
 use std::fs::File;
 use std::os::windows::ffi::{OsStrExt, OsStringExt};
-use std::os::windows::prelude::AsRawHandle;
 use std::path::{Path, PathBuf};
 
 pub(crate) trait PathGetExt {