Synchronize platform adaptors for OsString/OsStr

* Order items as the average of the two adaptors. Enables easier diffs.
* Consistently apply #[inline].
* Implement FromInner<Vec<u8>> for bytes::Buf.
* Implement Clone::clone_from for wtf8::Buf.

2 files changed, 119 insertions, 74 deletions

diff --git a/library/std/src/sys/os_str/bytes.rs b/library/std/src/sys/os_str/bytes.rs
index 5b65d862be1..1d337694944 100644
--- a/library/std/src/sys/os_str/bytes.rs
+++ b/library/std/src/sys/os_str/bytes.rs
@@ -8,7 +8,7 @@ use crate::collections::TryReserveError;
 use crate::fmt::Write;
 use crate::rc::Rc;
 use crate::sync::Arc;
-use crate::sys_common::{AsInner, IntoInner};
+use crate::sys_common::{AsInner, FromInner, IntoInner};
 use crate::{fmt, mem, str};
 
 #[cfg(test)]
@@ -25,6 +25,37 @@ pub struct Slice {
     pub inner: [u8],
 }
 
+impl IntoInner<Vec<u8>> for Buf {
+    fn into_inner(self) -> Vec<u8> {
+        self.inner
+    }
+}
+
+impl FromInner<Vec<u8>> for Buf {
+    fn from_inner(inner: Vec<u8>) -> Self {
+        Buf { inner }
+    }
+}
+
+impl AsInner<[u8]> for Buf {
+    #[inline]
+    fn as_inner(&self) -> &[u8] {
+        &self.inner
+    }
+}
+
+impl fmt::Debug for Buf {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        fmt::Debug::fmt(self.as_slice(), f)
+    }
+}
+
+impl fmt::Display for Buf {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        fmt::Display::fmt(self.as_slice(), f)
+    }
+}
+
 impl fmt::Debug for Slice {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         fmt::Debug::fmt(&self.inner.utf8_chunks().debug(), f)
@@ -55,18 +86,6 @@ impl fmt::Display for Slice {
     }
 }
 
-impl fmt::Debug for Buf {
-    fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
-        fmt::Debug::fmt(self.as_slice(), formatter)
-    }
-}
-
-impl fmt::Display for Buf {
-    fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
-        fmt::Display::fmt(self.as_slice(), formatter)
-    }
-}
-
 impl Clone for Buf {
     #[inline]
     fn clone(&self) -> Self {
@@ -79,19 +98,6 @@ impl Clone for Buf {
     }
 }
 
-impl IntoInner<Vec<u8>> for Buf {
-    fn into_inner(self) -> Vec<u8> {
-        self.inner
-    }
-}
-
-impl AsInner<[u8]> for Buf {
-    #[inline]
-    fn as_inner(&self) -> &[u8] {
-        &self.inner
-    }
-}
-
 impl Buf {
     #[inline]
     pub fn into_encoded_bytes(self) -> Vec<u8> {
@@ -103,6 +109,12 @@ impl Buf {
         Self { inner: s }
     }
 
+    #[inline]
+    pub fn into_string(self) -> Result<String, Buf> {
+        String::from_utf8(self.inner).map_err(|p| Buf { inner: p.into_bytes() })
+    }
+
+    #[inline]
     pub fn from_string(s: String) -> Buf {
         Buf { inner: s.into_bytes() }
     }
@@ -123,6 +135,11 @@ impl Buf {
     }
 
     #[inline]
+    pub fn push_slice(&mut self, s: &Slice) {
+        self.inner.extend_from_slice(&s.inner)
+    }
+
+    #[inline]
     pub fn reserve(&mut self, additional: usize) {
         self.inner.reserve(additional)
     }
@@ -157,7 +174,7 @@ impl Buf {
         // SAFETY: Slice just wraps [u8],
         // and &*self.inner is &[u8], therefore
         // transmuting &[u8] to &Slice is safe.
-        unsafe { mem::transmute(&*self.inner) }
+        unsafe { mem::transmute(self.inner.as_slice()) }
     }
 
     #[inline]
@@ -165,15 +182,7 @@ impl Buf {
         // SAFETY: Slice just wraps [u8],
         // and &mut *self.inner is &mut [u8], therefore
         // transmuting &mut [u8] to &mut Slice is safe.
-        unsafe { mem::transmute(&mut *self.inner) }
-    }
-
-    pub fn into_string(self) -> Result<String, Buf> {
-        String::from_utf8(self.inner).map_err(|p| Buf { inner: p.into_bytes() })
-    }
-
-    pub fn push_slice(&mut self, s: &Slice) {
-        self.inner.extend_from_slice(&s.inner)
+        unsafe { mem::transmute(self.inner.as_mut_slice()) }
     }
 
     #[inline]
@@ -278,18 +287,22 @@ impl Slice {
         unsafe { Slice::from_encoded_bytes_unchecked(s.as_bytes()) }
     }
 
+    #[inline]
     pub fn to_str(&self) -> Result<&str, crate::str::Utf8Error> {
         str::from_utf8(&self.inner)
     }
 
+    #[inline]
     pub fn to_string_lossy(&self) -> Cow<'_, str> {
         String::from_utf8_lossy(&self.inner)
     }
 
+    #[inline]
     pub fn to_owned(&self) -> Buf {
         Buf { inner: self.inner.to_vec() }
     }
 
+    #[inline]
     pub fn clone_into(&self, buf: &mut Buf) {
         self.inner.clone_into(&mut buf.inner)
     }
@@ -300,6 +313,7 @@ impl Slice {
         unsafe { mem::transmute(boxed) }
     }
 
+    #[inline]
     pub fn empty_box() -> Box<Slice> {
         let boxed: Box<[u8]> = Default::default();
         unsafe { mem::transmute(boxed) }
diff --git a/library/std/src/sys/os_str/wtf8.rs b/library/std/src/sys/os_str/wtf8.rs
index a4ad5966afe..19728d33990 100644
--- a/library/std/src/sys/os_str/wtf8.rs
+++ b/library/std/src/sys/os_str/wtf8.rs
@@ -10,11 +10,16 @@ use crate::sys_common::wtf8::{Wtf8, Wtf8Buf, check_utf8_boundary};
 use crate::sys_common::{AsInner, FromInner, IntoInner};
 use crate::{fmt, mem};
 
-#[derive(Clone, Hash)]
+#[derive(Hash)]
 pub struct Buf {
     pub inner: Wtf8Buf,
 }
 
+#[repr(transparent)]
+pub struct Slice {
+    pub inner: Wtf8,
+}
+
 impl IntoInner<Wtf8Buf> for Buf {
     fn into_inner(self) -> Wtf8Buf {
         self.inner
@@ -35,31 +40,38 @@ impl AsInner<Wtf8> for Buf {
 }
 
 impl fmt::Debug for Buf {
-    fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
-        fmt::Debug::fmt(self.as_slice(), formatter)
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        fmt::Debug::fmt(self.as_slice(), f)
     }
 }
 
 impl fmt::Display for Buf {
-    fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
-        fmt::Display::fmt(self.as_slice(), formatter)
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        fmt::Display::fmt(self.as_slice(), f)
     }
 }
 
-#[repr(transparent)]
-pub struct Slice {
-    pub inner: Wtf8,
-}
-
 impl fmt::Debug for Slice {
-    fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
-        fmt::Debug::fmt(&self.inner, formatter)
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        fmt::Debug::fmt(&self.inner, f)
     }
 }
 
 impl fmt::Display for Slice {
-    fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
-        fmt::Display::fmt(&self.inner, formatter)
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        fmt::Display::fmt(&self.inner, f)
+    }
+}
+
+impl Clone for Buf {
+    #[inline]
+    fn clone(&self) -> Self {
+        Buf { inner: self.inner.clone() }
+    }
+
+    #[inline]
+    fn clone_from(&mut self, source: &Self) {
+        self.inner.clone_from(&source.inner)
     }
 }
 
@@ -74,62 +86,57 @@ impl Buf {
         unsafe { Self { inner: Wtf8Buf::from_bytes_unchecked(s) } }
     }
 
-    pub fn with_capacity(capacity: usize) -> Buf {
-        Buf { inner: Wtf8Buf::with_capacity(capacity) }
-    }
-
-    pub fn clear(&mut self) {
-        self.inner.clear()
-    }
-
-    pub fn capacity(&self) -> usize {
-        self.inner.capacity()
+    #[inline]
+    pub fn into_string(self) -> Result<String, Buf> {
+        self.inner.into_string().map_err(|buf| Buf { inner: buf })
     }
 
+    #[inline]
     pub fn from_string(s: String) -> Buf {
         Buf { inner: Wtf8Buf::from_string(s) }
     }
 
-    pub fn as_slice(&self) -> &Slice {
-        // SAFETY: Slice is just a wrapper for Wtf8,
-        // and self.inner.as_slice() returns &Wtf8.
-        // Therefore, transmuting &Wtf8 to &Slice is safe.
-        unsafe { mem::transmute(self.inner.as_slice()) }
+    #[inline]
+    pub fn with_capacity(capacity: usize) -> Buf {
+        Buf { inner: Wtf8Buf::with_capacity(capacity) }
     }
 
-    pub fn as_mut_slice(&mut self) -> &mut Slice {
-        // SAFETY: Slice is just a wrapper for Wtf8,
-        // and self.inner.as_mut_slice() returns &mut Wtf8.
-        // Therefore, transmuting &mut Wtf8 to &mut Slice is safe.
-        // Additionally, care should be taken to ensure the slice
-        // is always valid Wtf8.
-        unsafe { mem::transmute(self.inner.as_mut_slice()) }
+    #[inline]
+    pub fn clear(&mut self) {
+        self.inner.clear()
     }
 
-    pub fn into_string(self) -> Result<String, Buf> {
-        self.inner.into_string().map_err(|buf| Buf { inner: buf })
+    #[inline]
+    pub fn capacity(&self) -> usize {
+        self.inner.capacity()
     }
 
+    #[inline]
     pub fn push_slice(&mut self, s: &Slice) {
         self.inner.push_wtf8(&s.inner)
     }
 
+    #[inline]
     pub fn reserve(&mut self, additional: usize) {
         self.inner.reserve(additional)
     }
 
+    #[inline]
     pub fn try_reserve(&mut self, additional: usize) -> Result<(), TryReserveError> {
         self.inner.try_reserve(additional)
     }
 
+    #[inline]
     pub fn reserve_exact(&mut self, additional: usize) {
         self.inner.reserve_exact(additional)
     }
 
+    #[inline]
     pub fn try_reserve_exact(&mut self, additional: usize) -> Result<(), TryReserveError> {
         self.inner.try_reserve_exact(additional)
     }
 
+    #[inline]
     pub fn shrink_to_fit(&mut self) {
         self.inner.shrink_to_fit()
     }
@@ -140,6 +147,24 @@ impl Buf {
     }
 
     #[inline]
+    pub fn as_slice(&self) -> &Slice {
+        // SAFETY: Slice is just a wrapper for Wtf8,
+        // and self.inner.as_slice() returns &Wtf8.
+        // Therefore, transmuting &Wtf8 to &Slice is safe.
+        unsafe { mem::transmute(self.inner.as_slice()) }
+    }
+
+    #[inline]
+    pub fn as_mut_slice(&mut self) -> &mut Slice {
+        // SAFETY: Slice is just a wrapper for Wtf8,
+        // and self.inner.as_mut_slice() returns &mut Wtf8.
+        // Therefore, transmuting &mut Wtf8 to &mut Slice is safe.
+        // Additionally, care should be taken to ensure the slice
+        // is always valid Wtf8.
+        unsafe { mem::transmute(self.inner.as_mut_slice()) }
+    }
+
+    #[inline]
     pub fn leak<'a>(self) -> &'a mut Slice {
         unsafe { mem::transmute(self.inner.leak()) }
     }
@@ -194,6 +219,7 @@ impl Slice {
     }
 
     #[track_caller]
+    #[inline]
     pub fn check_public_boundary(&self, index: usize) {
         check_utf8_boundary(&self.inner, index);
     }
@@ -203,18 +229,22 @@ impl Slice {
         unsafe { mem::transmute(Wtf8::from_str(s)) }
     }
 
+    #[inline]
     pub fn to_str(&self) -> Result<&str, crate::str::Utf8Error> {
         self.inner.as_str()
     }
 
+    #[inline]
     pub fn to_string_lossy(&self) -> Cow<'_, str> {
         self.inner.to_string_lossy()
     }
 
+    #[inline]
     pub fn to_owned(&self) -> Buf {
         Buf { inner: self.inner.to_owned() }
     }
 
+    #[inline]
     pub fn clone_into(&self, buf: &mut Buf) {
         self.inner.clone_into(&mut buf.inner)
     }
@@ -224,6 +254,7 @@ impl Slice {
         unsafe { mem::transmute(self.inner.into_box()) }
     }
 
+    #[inline]
     pub fn empty_box() -> Box<Slice> {
         unsafe { mem::transmute(Wtf8::empty_box()) }
     }