5 files changed, 19 insertions, 13 deletions
diff --git a/src/libstd/future.rs b/src/libstd/future.rs
index 2da775fdc94..c1cc36f3b41 100644
--- a/src/libstd/future.rs
+++ b/src/libstd/future.rs
@@ -43,7 +43,7 @@ impl<T: Generator<Yield = ()>> !Unpin for GenFuture<T> {}
 impl<T: Generator<Yield = ()>> Future for GenFuture<T> {
     type Output = T::Return;
     fn poll(self: PinMut<Self>, cx: &mut task::Context) -> Poll<Self::Output> {
-        set_task_cx(cx, || match unsafe { PinMut::get_mut(self).0.resume() } {
+        set_task_cx(cx, || match unsafe { PinMut::get_mut_unchecked(self).0.resume() } {
             GeneratorState::Yielded(()) => Poll::Pending,
             GeneratorState::Complete(x) => Poll::Ready(x),
         })
diff --git a/src/libstd/macros.rs b/src/libstd/macros.rs
index a856e7736fb..75f038407c1 100644
--- a/src/libstd/macros.rs
+++ b/src/libstd/macros.rs
@@ -38,10 +38,13 @@
 /// The multi-argument form of this macro panics with a string and has the
 /// [`format!`] syntax for building a string.
 ///
+/// See also the macro [`compile_error!`], for raising errors during compilation.
+///
 /// [runwrap]: ../std/result/enum.Result.html#method.unwrap
 /// [`Option`]: ../std/option/enum.Option.html#method.unwrap
 /// [`Result`]: ../std/result/enum.Result.html
 /// [`format!`]: ../std/macro.format.html
+/// [`compile_error!`]: ../std/macro.compile_error.html
 /// [book]: ../book/second-edition/ch09-01-unrecoverable-errors-with-panic.html
 ///
 /// # Current implementation
@@ -305,13 +308,16 @@ pub mod builtin {
     /// Unconditionally causes compilation to fail with the given error message when encountered.
     ///
     /// This macro should be used when a crate uses a conditional compilation strategy to provide
-    /// better error messages for erroneous conditions.
+    /// better error messages for erroneous conditions. It's the compiler-level form of [`panic!`],
+    /// which emits an error at *runtime*, rather than during compilation.
     ///
     /// # Examples
     ///
     /// Two such examples are macros and `#[cfg]` environments.
     ///
-    /// Emit better compiler error if a macro is passed invalid values.
+    /// Emit better compiler error if a macro is passed invalid values. Without the final branch,
+    /// the compiler would still emit an error, but the error's message would not mention the two
+    /// valid values.
     ///
     /// ```compile_fail
     /// macro_rules! give_me_foo_or_bar {
@@ -332,6 +338,8 @@ pub mod builtin {
     /// #[cfg(not(any(feature = "foo", feature = "bar")))]
     /// compile_error!("Either feature \"foo\" or \"bar\" must be enabled for this crate.")
     /// ```
+    ///
+    /// [`panic!`]: ../std/macro.panic.html
     #[stable(feature = "compile_error_macro", since = "1.20.0")]
     #[macro_export]
     macro_rules! compile_error {
diff --git a/src/libstd/panic.rs b/src/libstd/panic.rs
index 2c11c262488..451420ae88a 100644
--- a/src/libstd/panic.rs
+++ b/src/libstd/panic.rs
@@ -327,14 +327,9 @@ impl<T: fmt::Debug> fmt::Debug for AssertUnwindSafe<T> {
 impl<'a, F: Future> Future for AssertUnwindSafe<F> {
     type Output = F::Output;
 
-    fn poll(mut self: PinMut<Self>, cx: &mut task::Context) -> Poll<Self::Output> {
-        unsafe {
-            let pinned_field = PinMut::new_unchecked(
-                &mut PinMut::get_mut(self.reborrow()).0
-            );
-
-            pinned_field.poll(cx)
-        }
+    fn poll(self: PinMut<Self>, cx: &mut task::Context) -> Poll<Self::Output> {
+        let pinned_field = unsafe { PinMut::map_unchecked(self, |x| &mut x.0) };
+        pinned_field.poll(cx)
     }
 }
 
diff --git a/src/libstd/sys/mod.rs b/src/libstd/sys/mod.rs
index 1231898ed7e..c44db3b1072 100644
--- a/src/libstd/sys/mod.rs
+++ b/src/libstd/sys/mod.rs
@@ -67,6 +67,7 @@ cfg_if! {
         // (missing things in `libc` which is empty) so just omit everything
         // with an empty module
         #[unstable(issue = "0", feature = "std_internals")]
+        #[allow(missing_docs)]
         pub mod unix_ext {}
     } else {
         // On other platforms like Windows document the bare bones of unix
@@ -80,11 +81,13 @@ cfg_if! {
 cfg_if! {
     if #[cfg(windows)] {
         // On windows we'll just be documenting what's already available
+        #[allow(missing_docs)]
         pub use self::ext as windows_ext;
     } else if #[cfg(any(target_os = "cloudabi", target_arch = "wasm32"))] {
         // On CloudABI and wasm right now the shim below doesn't compile, so
         // just omit it
         #[unstable(issue = "0", feature = "std_internals")]
+        #[allow(missing_docs)]
         pub mod windows_ext {}
     } else {
         // On all other platforms (aka linux/osx/etc) then pull in a "minimal"
diff --git a/src/libstd/sys/unix/fs.rs b/src/libstd/sys/unix/fs.rs
index e186b115821..662a76d6725 100644
--- a/src/libstd/sys/unix/fs.rs
+++ b/src/libstd/sys/unix/fs.rs
@@ -803,7 +803,7 @@ pub fn stat(p: &Path) -> io::Result<FileAttr> {
     let p = cstr(p)?;
     let mut stat: stat64 = unsafe { mem::zeroed() };
     cvt(unsafe {
-        stat64(p.as_ptr(), &mut stat as *mut _ as *mut _)
+        stat64(p.as_ptr(), &mut stat)
     })?;
     Ok(FileAttr { stat: stat })
 }
@@ -812,7 +812,7 @@ pub fn lstat(p: &Path) -> io::Result<FileAttr> {
     let p = cstr(p)?;
     let mut stat: stat64 = unsafe { mem::zeroed() };
     cvt(unsafe {
-        lstat64(p.as_ptr(), &mut stat as *mut _ as *mut _)
+        lstat64(p.as_ptr(), &mut stat)
     })?;
     Ok(FileAttr { stat: stat })
 }