Auto merge of #87413 - JohnTitor:rollup-dht22jk, r=JohnTitor

Rollup of 14 pull requests

Successful merges:

 - #86410 (VecMap::get_value_matching should return just one element)
 - #86790 (Document iteration order of `retain` functions)
 - #87171 (Remove Option from BufWriter)
 - #87175 (Stabilize `into_parts()` and `into_error()`)
 - #87185 (Fix panics on Windows when the build was cancelled)
 - #87191 (Package LLVM libs for the target rather than the build host)
 - #87255 (better support for running libcore tests with Miri)
 - #87266 (Add testcase for 87076)
 - #87283 (Add `--codegen-backends=foo,bar` configure flag)
 - #87322 (fix: clarify suggestion that `&T` must refer to `T: Sync` for `&T: Send`)
 - #87358 (Fix `--dry-run` when download-ci-llvm is set)
 - #87380 (Don't default to `submodules = true` unless the rust repo has a .git directory)
 - #87398 (Add test for fonts used for module items)
 - #87412 (Add missing article)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

4 files changed, 18 insertions, 14 deletions

diff --git a/library/std/src/collections/hash/map.rs b/library/std/src/collections/hash/map.rs
index fac285c96f0..4a5efab9055 100644
--- a/library/std/src/collections/hash/map.rs
+++ b/library/std/src/collections/hash/map.rs
@@ -934,6 +934,7 @@ where
     /// Retains only the elements specified by the predicate.
     ///
     /// In other words, remove all pairs `(k, v)` such that `f(&k, &mut v)` returns `false`.
+    /// The elements are visited in unsorted (and unspecified) order.
     ///
     /// # Examples
     ///
diff --git a/library/std/src/collections/hash/set.rs b/library/std/src/collections/hash/set.rs
index 272e1c2be2b..1a2a8afac8b 100644
--- a/library/std/src/collections/hash/set.rs
+++ b/library/std/src/collections/hash/set.rs
@@ -912,6 +912,7 @@ where
     /// Retains only the elements specified by the predicate.
     ///
     /// In other words, remove all elements `e` such that `f(&e)` returns `false`.
+    /// The elements are visited in unsorted (and unspecified) order.
     ///
     /// # Examples
     ///
diff --git a/library/std/src/io/buffered/bufwriter.rs b/library/std/src/io/buffered/bufwriter.rs
index ef2769d431f..c98244132be 100644
--- a/library/std/src/io/buffered/bufwriter.rs
+++ b/library/std/src/io/buffered/bufwriter.rs
@@ -68,7 +68,7 @@ use crate::ptr;
 /// [`flush`]: BufWriter::flush
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct BufWriter<W: Write> {
-    inner: Option<W>,
+    inner: W,
     // The buffer. Avoid using this like a normal `Vec` in common code paths.
     // That is, don't use `buf.push`, `buf.extend_from_slice`, or any other
     // methods that require bounds checking or the like. This makes an enormous
@@ -112,7 +112,7 @@ impl<W: Write> BufWriter<W> {
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn with_capacity(capacity: usize, inner: W) -> BufWriter<W> {
-        BufWriter { inner: Some(inner), buf: Vec::with_capacity(capacity), panicked: false }
+        BufWriter { inner, buf: Vec::with_capacity(capacity), panicked: false }
     }
 
     /// Send data in our local buffer into the inner writer, looping as
@@ -161,10 +161,9 @@ impl<W: Write> BufWriter<W> {
         }
 
         let mut guard = BufGuard::new(&mut self.buf);
-        let inner = self.inner.as_mut().unwrap();
         while !guard.done() {
             self.panicked = true;
-            let r = inner.write(guard.remaining());
+            let r = self.inner.write(guard.remaining());
             self.panicked = false;
 
             match r {
@@ -212,7 +211,7 @@ impl<W: Write> BufWriter<W> {
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn get_ref(&self) -> &W {
-        self.inner.as_ref().unwrap()
+        &self.inner
     }
 
     /// Gets a mutable reference to the underlying writer.
@@ -232,7 +231,7 @@ impl<W: Write> BufWriter<W> {
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn get_mut(&mut self) -> &mut W {
-        self.inner.as_mut().unwrap()
+        &mut self.inner
     }
 
     /// Returns a reference to the internally buffered data.
@@ -308,7 +307,7 @@ impl<W: Write> BufWriter<W> {
     pub fn into_inner(mut self) -> Result<W, IntoInnerError<BufWriter<W>>> {
         match self.flush_buf() {
             Err(e) => Err(IntoInnerError::new(self, e)),
-            Ok(()) => Ok(self.inner.take().unwrap()),
+            Ok(()) => Ok(self.into_raw_parts().0),
         }
     }
 
@@ -339,7 +338,12 @@ impl<W: Write> BufWriter<W> {
     pub fn into_raw_parts(mut self) -> (W, Result<Vec<u8>, WriterPanicked>) {
         let buf = mem::take(&mut self.buf);
         let buf = if !self.panicked { Ok(buf) } else { Err(WriterPanicked { buf }) };
-        (self.inner.take().unwrap(), buf)
+
+        // SAFETY: forget(self) prevents double dropping inner
+        let inner = unsafe { ptr::read(&mut self.inner) };
+        mem::forget(self);
+
+        (inner, buf)
     }
 
     // Ensure this function does not get inlined into `write`, so that it
@@ -643,7 +647,7 @@ where
 {
     fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
         fmt.debug_struct("BufWriter")
-            .field("writer", &self.inner.as_ref().unwrap())
+            .field("writer", &self.inner)
             .field("buffer", &format_args!("{}/{}", self.buf.len(), self.buf.capacity()))
             .finish()
     }
@@ -663,7 +667,7 @@ impl<W: Write + Seek> Seek for BufWriter<W> {
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<W: Write> Drop for BufWriter<W> {
     fn drop(&mut self) {
-        if self.inner.is_some() && !self.panicked {
+        if !self.panicked {
             // dtors should not panic, so we ignore a failed flush
             let _r = self.flush_buf();
         }
diff --git a/library/std/src/io/buffered/mod.rs b/library/std/src/io/buffered/mod.rs
index 65497817f81..38076ab3a2b 100644
--- a/library/std/src/io/buffered/mod.rs
+++ b/library/std/src/io/buffered/mod.rs
@@ -133,7 +133,6 @@ impl<W> IntoInnerError<W> {
     ///
     /// # Example
     /// ```
-    /// #![feature(io_into_inner_error_parts)]
     /// use std::io::{BufWriter, ErrorKind, Write};
     ///
     /// let mut not_enough_space = [0u8; 10];
@@ -143,7 +142,7 @@ impl<W> IntoInnerError<W> {
     /// let err = into_inner_err.into_error();
     /// assert_eq!(err.kind(), ErrorKind::WriteZero);
     /// ```
-    #[unstable(feature = "io_into_inner_error_parts", issue = "79704")]
+    #[stable(feature = "io_into_inner_error_parts", since = "1.55.0")]
     pub fn into_error(self) -> Error {
         self.1
     }
@@ -156,7 +155,6 @@ impl<W> IntoInnerError<W> {
     ///
     /// # Example
     /// ```
-    /// #![feature(io_into_inner_error_parts)]
     /// use std::io::{BufWriter, ErrorKind, Write};
     ///
     /// let mut not_enough_space = [0u8; 10];
@@ -167,7 +165,7 @@ impl<W> IntoInnerError<W> {
     /// 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")]
+    #[stable(feature = "io_into_inner_error_parts", since = "1.55.0")]
     pub fn into_parts(self) -> (Error, W) {
         (self.1, self.0)
     }