5 files changed, 62 insertions, 12 deletions
diff --git a/library/std/src/alloc.rs b/library/std/src/alloc.rs
index 375b015ccc8..819d57a934d 100644
--- a/library/std/src/alloc.rs
+++ b/library/std/src/alloc.rs
@@ -149,7 +149,7 @@ impl System {
         }
     }
 
-    // SAFETY: Same as `AllocRef::grow`
+    // SAFETY: Same as `Allocator::grow`
     #[inline]
     unsafe fn grow_impl(
         &self,
@@ -190,29 +190,29 @@ impl System {
             old_size => unsafe {
                 let new_ptr = self.alloc_impl(new_layout, zeroed)?;
                 ptr::copy_nonoverlapping(ptr.as_ptr(), new_ptr.as_mut_ptr(), old_size);
-                AllocRef::dealloc(&self, ptr, old_layout);
+                Allocator::deallocate(&self, ptr, old_layout);
                 Ok(new_ptr)
             },
         }
     }
 }
 
-// The AllocRef impl checks the layout size to be non-zero and forwards to the GlobalAlloc impl,
+// The Allocator impl checks the layout size to be non-zero and forwards to the GlobalAlloc impl,
 // which is in `std::sys::*::alloc`.
 #[unstable(feature = "allocator_api", issue = "32838")]
-unsafe impl AllocRef for System {
+unsafe impl Allocator for System {
     #[inline]
-    fn alloc(&self, layout: Layout) -> Result<NonNull<[u8]>, AllocError> {
+    fn allocate(&self, layout: Layout) -> Result<NonNull<[u8]>, AllocError> {
         self.alloc_impl(layout, false)
     }
 
     #[inline]
-    fn alloc_zeroed(&self, layout: Layout) -> Result<NonNull<[u8]>, AllocError> {
+    fn allocate_zeroed(&self, layout: Layout) -> Result<NonNull<[u8]>, AllocError> {
         self.alloc_impl(layout, true)
     }
 
     #[inline]
-    unsafe fn dealloc(&self, ptr: NonNull<u8>, layout: Layout) {
+    unsafe fn deallocate(&self, ptr: NonNull<u8>, layout: Layout) {
         if layout.size() != 0 {
             // SAFETY: `layout` is non-zero in size,
             // other conditions must be upheld by the caller
@@ -257,7 +257,7 @@ unsafe impl AllocRef for System {
         match new_layout.size() {
             // SAFETY: conditions must be upheld by the caller
             0 => unsafe {
-                AllocRef::dealloc(&self, ptr, old_layout);
+                Allocator::deallocate(&self, ptr, old_layout);
                 Ok(NonNull::slice_from_raw_parts(new_layout.dangling(), 0))
             },
 
@@ -277,9 +277,9 @@ unsafe impl AllocRef for System {
             // `new_ptr`. Thus, the call to `copy_nonoverlapping` is safe. The safety contract
             // for `dealloc` must be upheld by the caller.
             new_size => unsafe {
-                let new_ptr = AllocRef::alloc(&self, new_layout)?;
+                let new_ptr = Allocator::allocate(&self, new_layout)?;
                 ptr::copy_nonoverlapping(ptr.as_ptr(), new_ptr.as_mut_ptr(), new_size);
-                AllocRef::dealloc(&self, ptr, old_layout);
+                Allocator::deallocate(&self, ptr, old_layout);
                 Ok(new_ptr)
             },
         }
diff --git a/library/std/src/io/buffered/mod.rs b/library/std/src/io/buffered/mod.rs
index f9caeaf98e2..65497817f81 100644
--- a/library/std/src/io/buffered/mod.rs
+++ b/library/std/src/io/buffered/mod.rs
@@ -126,6 +126,51 @@ impl<W> IntoInnerError<W> {
     pub fn into_inner(self) -> W {
         self.0
     }
+
+    /// Consumes the [`IntoInnerError`] and returns the error which caused the call to
+    /// [`BufWriter::into_inner()`] to fail.  Unlike `error`, this can be used to
+    /// obtain ownership of the underlying error.
+    ///
+    /// # Example
+    /// ```
+    /// #![feature(io_into_inner_error_parts)]
+    /// use std::io::{BufWriter, ErrorKind, Write};
+    ///
+    /// let mut not_enough_space = [0u8; 10];
+    /// let mut stream = BufWriter::new(not_enough_space.as_mut());
+    /// write!(stream, "this cannot be actually written").unwrap();
+    /// let into_inner_err = stream.into_inner().expect_err("now we discover it's too small");
+    /// let err = into_inner_err.into_error();
+    /// assert_eq!(err.kind(), ErrorKind::WriteZero);
+    /// ```
+    #[unstable(feature = "io_into_inner_error_parts", issue = "79704")]
+    pub fn into_error(self) -> Error {
+        self.1
+    }
+
+    /// Consumes the [`IntoInnerError`] and returns the error which caused the call to
+    /// [`BufWriter::into_inner()`] to fail, and the underlying writer.
+    ///
+    /// This can be used to simply obtain ownership of the underlying error; it can also be used for
+    /// advanced error recovery.
+    ///
+    /// # Example
+    /// ```
+    /// #![feature(io_into_inner_error_parts)]
+    /// use std::io::{BufWriter, ErrorKind, Write};
+    ///
+    /// let mut not_enough_space = [0u8; 10];
+    /// let mut stream = BufWriter::new(not_enough_space.as_mut());
+    /// write!(stream, "this cannot be actually written").unwrap();
+    /// let into_inner_err = stream.into_inner().expect_err("now we discover it's too small");
+    /// let (err, recovered_writer) = into_inner_err.into_parts();
+    /// assert_eq!(err.kind(), ErrorKind::WriteZero);
+    /// assert_eq!(recovered_writer.buffer(), b"t be actually written");
+    /// ```
+    #[unstable(feature = "io_into_inner_error_parts", issue = "79704")]
+    pub fn into_parts(self) -> (Error, W) {
+        (self.1, self.0)
+    }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
diff --git a/library/std/src/io/impls.rs b/library/std/src/io/impls.rs
index 6b3c86cb0df..00bf8b9af73 100644
--- a/library/std/src/io/impls.rs
+++ b/library/std/src/io/impls.rs
@@ -306,6 +306,10 @@ impl BufRead for &[u8] {
 ///
 /// Note that writing updates the slice to point to the yet unwritten part.
 /// The slice will be empty when it has been completely overwritten.
+///
+/// If the number of bytes to be written exceeds the size of the slice, write operations will
+/// return short writes: ultimately, `Ok(0)`; in this situation, `write_all` returns an error of
+/// kind `ErrorKind::WriteZero`.
 #[stable(feature = "rust1", since = "1.0.0")]
 impl Write for &mut [u8] {
     #[inline]
diff --git a/library/std/src/lib.rs b/library/std/src/lib.rs
index 83eb847697d..6c240cb4c3e 100644
--- a/library/std/src/lib.rs
+++ b/library/std/src/lib.rs
@@ -212,6 +212,7 @@
     all(target_vendor = "fortanix", target_env = "sgx"),
     feature(slice_index_methods, coerce_unsized, sgx_platform)
 )]
+#![deny(rustc::existing_doc_keyword)]
 #![cfg_attr(all(test, target_vendor = "fortanix", target_env = "sgx"), feature(fixed_size_array))]
 // std is implemented with unstable features, many of which are internal
 // compiler details that will never be stable
diff --git a/library/std/src/primitive_docs.rs b/library/std/src/primitive_docs.rs
index 83a282c8cd6..55171ef2292 100644
--- a/library/std/src/primitive_docs.rs
+++ b/library/std/src/primitive_docs.rs
@@ -198,7 +198,7 @@ mod prim_bool {}
 /// words, they can't return `!` from every code path. As an example, this code doesn't compile:
 ///
 /// ```compile_fail
-/// use core::ops::Add;
+/// use std::ops::Add;
 ///
 /// fn foo() -> impl Add<u32> {
 ///     unimplemented!()
@@ -208,7 +208,7 @@ mod prim_bool {}
 /// But this code does:
 ///
 /// ```
-/// use core::ops::Add;
+/// use std::ops::Add;
 ///
 /// fn foo() -> impl Add<u32> {
 ///     if true {