Auto merge of rust-lang#134332 - Zalathar:rollup-oe23hkw, r=Zalathar

Rollup of 7 pull requests

Successful merges:

 - rust-lang#130361 (std::net: Solaris supports `SOCK_CLOEXEC` as well since 11.4.)
 - rust-lang#133406 (Add value accessor methods to `Mutex` and `RwLock`)
 - rust-lang#133633 (don't show the full linker args unless `--verbose` is passed)
 - rust-lang#134285 (Add some convenience helper methods on `hir::Safety`)
 - rust-lang#134310 (Add clarity to the examples of some `Vec` & `VecDeque` methods)
 - rust-lang#134313 (Don't make a def id for `impl_trait_in_bindings`)
 - rust-lang#134315 (A couple of polonius fact generation cleanups)

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

Author: bors

alloc/src/collections/vec_deque/mod.rs

@@ -1869,7 +1869,7 @@ impl<T, A: Allocator> VecDeque<T, A> {
     ///
     /// # Panics
     ///
-    /// Panics if `index` is greater than deque's length
+    /// Panics if `index` is strictly greater than deque's length
     ///
     /// # Examples
     ///
@@ -1884,6 +1884,9 @@ impl<T, A: Allocator> VecDeque<T, A> {
     ///
     /// vec_deque.insert(1, 'd');
     /// assert_eq!(vec_deque, &['a', 'd', 'b', 'c']);
+    ///
+    /// vec_deque.insert(4, 'e');
+    /// assert_eq!(vec_deque, &['a', 'd', 'b', 'c', 'e']);
     /// ```
     #[stable(feature = "deque_extras_15", since = "1.5.0")]
     #[track_caller]
@@ -1928,13 +1931,13 @@ impl<T, A: Allocator> VecDeque<T, A> {
     /// use std::collections::VecDeque;
     ///
     /// let mut buf = VecDeque::new();
-    /// buf.push_back(1);
-    /// buf.push_back(2);
-    /// buf.push_back(3);
-    /// assert_eq!(buf, [1, 2, 3]);
+    /// buf.push_back('a');
+    /// buf.push_back('b');
+    /// buf.push_back('c');
+    /// assert_eq!(buf, ['a', 'b', 'c']);
     ///
-    /// assert_eq!(buf.remove(1), Some(2));
-    /// assert_eq!(buf, [1, 3]);
+    /// assert_eq!(buf.remove(1), Some('b'));
+    /// assert_eq!(buf, ['a', 'c']);
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
     #[rustc_confusables("delete", "take")]
@@ -1982,10 +1985,10 @@ impl<T, A: Allocator> VecDeque<T, A> {
     /// ```
     /// use std::collections::VecDeque;
     ///
-    /// let mut buf: VecDeque<_> = [1, 2, 3].into();
+    /// let mut buf: VecDeque<_> = ['a', 'b', 'c'].into();
     /// let buf2 = buf.split_off(1);
-    /// assert_eq!(buf, [1]);
-    /// assert_eq!(buf2, [2, 3]);
+    /// assert_eq!(buf, ['a']);
+    /// assert_eq!(buf2, ['b', 'c']);
     /// ```
     #[inline]
     #[must_use = "use `.truncate()` if you don't need the other half"]

alloc/src/vec/mod.rs

@@ -1953,11 +1953,11 @@ impl<T, A: Allocator> Vec<T, A> {
     /// # Examples
     ///
     /// ```
-    /// let mut vec = vec![1, 2, 3];
-    /// vec.insert(1, 4);
-    /// assert_eq!(vec, [1, 4, 2, 3]);
-    /// vec.insert(4, 5);
-    /// assert_eq!(vec, [1, 4, 2, 3, 5]);
+    /// let mut vec = vec!['a', 'b', 'c'];
+    /// vec.insert(1, 'd');
+    /// assert_eq!(vec, ['a', 'd', 'b', 'c']);
+    /// vec.insert(4, 'e');
+    /// assert_eq!(vec, ['a', 'd', 'b', 'c', 'e']);
     /// ```
     ///
     /// # Time complexity
@@ -2024,9 +2024,9 @@ impl<T, A: Allocator> Vec<T, A> {
     /// # Examples
     ///
     /// ```
-    /// let mut v = vec![1, 2, 3];
-    /// assert_eq!(v.remove(1), 2);
-    /// assert_eq!(v, [1, 3]);
+    /// let mut v = vec!['a', 'b', 'c'];
+    /// assert_eq!(v.remove(1), 'b');
+    /// assert_eq!(v, ['a', 'c']);
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
     #[track_caller]
@@ -2715,10 +2715,10 @@ impl<T, A: Allocator> Vec<T, A> {
     /// # Examples
     ///
     /// ```
-    /// let mut vec = vec![1, 2, 3];
+    /// let mut vec = vec!['a', 'b', 'c'];
     /// let vec2 = vec.split_off(1);
-    /// assert_eq!(vec, [1]);
-    /// assert_eq!(vec2, [2, 3]);
+    /// assert_eq!(vec, ['a']);
+    /// assert_eq!(vec2, ['b', 'c']);
     /// ```
     #[cfg(not(no_global_oom_handling))]
     #[inline]
@@ -2982,9 +2982,9 @@ impl<T: Clone, A: Allocator> Vec<T, A> {
     /// vec.resize(3, "world");
     /// assert_eq!(vec, ["hello", "world", "world"]);
     ///
-    /// let mut vec = vec![1, 2, 3, 4];
-    /// vec.resize(2, 0);
-    /// assert_eq!(vec, [1, 2]);
+    /// let mut vec = vec!['a', 'b', 'c', 'd'];
+    /// vec.resize(2, '_');
+    /// assert_eq!(vec, ['a', 'b']);
     /// ```
     #[cfg(not(no_global_oom_handling))]
     #[stable(feature = "vec_resize", since = "1.5.0")]

core/src/slice/mod.rs

@@ -1883,23 +1883,23 @@ impl<T> [T] {
     /// # Examples
     ///
     /// ```
-    /// let v = [1, 2, 3, 4, 5, 6];
+    /// let v = ['a', 'b', 'c'];
     ///
     /// {
     ///    let (left, right) = v.split_at(0);
     ///    assert_eq!(left, []);
-    ///    assert_eq!(right, [1, 2, 3, 4, 5, 6]);
+    ///    assert_eq!(right, ['a', 'b', 'c']);
     /// }
     ///
     /// {
     ///     let (left, right) = v.split_at(2);
-    ///     assert_eq!(left, [1, 2]);
-    ///     assert_eq!(right, [3, 4, 5, 6]);
+    ///     assert_eq!(left, ['a', 'b']);
+    ///     assert_eq!(right, ['c']);
     /// }
     ///
     /// {
-    ///     let (left, right) = v.split_at(6);
-    ///     assert_eq!(left, [1, 2, 3, 4, 5, 6]);
+    ///     let (left, right) = v.split_at(3);
+    ///     assert_eq!(left, ['a', 'b', 'c']);
     ///     assert_eq!(right, []);
     /// }
     /// ```
@@ -1969,23 +1969,23 @@ impl<T> [T] {
     /// # Examples
     ///
     /// ```
-    /// let v = [1, 2, 3, 4, 5, 6];
+    /// let v = ['a', 'b', 'c'];
     ///
     /// unsafe {
     ///    let (left, right) = v.split_at_unchecked(0);
     ///    assert_eq!(left, []);
-    ///    assert_eq!(right, [1, 2, 3, 4, 5, 6]);
+    ///    assert_eq!(right, ['a', 'b', 'c']);
     /// }
     ///
     /// unsafe {
     ///     let (left, right) = v.split_at_unchecked(2);
-    ///     assert_eq!(left, [1, 2]);
-    ///     assert_eq!(right, [3, 4, 5, 6]);
+    ///     assert_eq!(left, ['a', 'b']);
+    ///     assert_eq!(right, ['c']);
     /// }
     ///
     /// unsafe {
-    ///     let (left, right) = v.split_at_unchecked(6);
-    ///     assert_eq!(left, [1, 2, 3, 4, 5, 6]);
+    ///     let (left, right) = v.split_at_unchecked(3);
+    ///     assert_eq!(left, ['a', 'b', 'c']);
     ///     assert_eq!(right, []);
     /// }
     /// ```

std/src/sync/mutex.rs

@@ -4,10 +4,10 @@ mod tests;
 use crate::cell::UnsafeCell;
 use crate::fmt;
 use crate::marker::PhantomData;
-use crate::mem::ManuallyDrop;
+use crate::mem::{self, ManuallyDrop};
 use crate::ops::{Deref, DerefMut};
 use crate::ptr::NonNull;
-use crate::sync::{LockResult, TryLockError, TryLockResult, poison};
+use crate::sync::{LockResult, PoisonError, TryLockError, TryLockResult, poison};
 use crate::sys::sync as sys;
 
 /// A mutual exclusion primitive useful for protecting shared data
@@ -273,6 +273,100 @@ impl<T> Mutex<T> {
     pub const fn new(t: T) -> Mutex<T> {
         Mutex { inner: sys::Mutex::new(), poison: poison::Flag::new(), data: UnsafeCell::new(t) }
     }
+
+    /// Returns the contained value by cloning it.
+    ///
+    /// # Errors
+    ///
+    /// If another user of this mutex panicked while holding the mutex, then
+    /// this call will return an error instead.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(lock_value_accessors)]
+    ///
+    /// use std::sync::Mutex;
+    ///
+    /// let mut mutex = Mutex::new(7);
+    ///
+    /// assert_eq!(mutex.get_cloned().unwrap(), 7);
+    /// ```
+    #[unstable(feature = "lock_value_accessors", issue = "133407")]
+    pub fn get_cloned(&self) -> Result<T, PoisonError<()>>
+    where
+        T: Clone,
+    {
+        match self.lock() {
+            Ok(guard) => Ok((*guard).clone()),
+            Err(_) => Err(PoisonError::new(())),
+        }
+    }
+
+    /// Sets the contained value.
+    ///
+    /// # Errors
+    ///
+    /// If another user of this mutex panicked while holding the mutex, then
+    /// this call will return an error containing the provided `value` instead.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(lock_value_accessors)]
+    ///
+    /// use std::sync::Mutex;
+    ///
+    /// let mut mutex = Mutex::new(7);
+    ///
+    /// assert_eq!(mutex.get_cloned().unwrap(), 7);
+    /// mutex.set(11).unwrap();
+    /// assert_eq!(mutex.get_cloned().unwrap(), 11);
+    /// ```
+    #[unstable(feature = "lock_value_accessors", issue = "133407")]
+    pub fn set(&self, value: T) -> Result<(), PoisonError<T>> {
+        if mem::needs_drop::<T>() {
+            // If the contained value has non-trivial destructor, we
+            // call that destructor after the lock being released.
+            self.replace(value).map(drop)
+        } else {
+            match self.lock() {
+                Ok(mut guard) => {
+                    *guard = value;
+
+                    Ok(())
+                }
+                Err(_) => Err(PoisonError::new(value)),
+            }
+        }
+    }
+
+    /// Replaces the contained value with `value`, and returns the old contained value.
+    ///
+    /// # Errors
+    ///
+    /// If another user of this mutex panicked while holding the mutex, then
+    /// this call will return an error containing the provided `value` instead.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(lock_value_accessors)]
+    ///
+    /// use std::sync::Mutex;
+    ///
+    /// let mut mutex = Mutex::new(7);
+    ///
+    /// assert_eq!(mutex.replace(11).unwrap(), 7);
+    /// assert_eq!(mutex.get_cloned().unwrap(), 11);
+    /// ```
+    #[unstable(feature = "lock_value_accessors", issue = "133407")]
+    pub fn replace(&self, value: T) -> LockResult<T> {
+        match self.lock() {
+            Ok(mut guard) => Ok(mem::replace(&mut *guard, value)),
+            Err(_) => Err(PoisonError::new(value)),
+        }
+    }
 }
 
 impl<T: ?Sized> Mutex<T> {
@@ -290,7 +384,8 @@ impl<T: ?Sized> Mutex<T> {
     /// # Errors
     ///
     /// If another user of this mutex panicked while holding the mutex, then
-    /// this call will return an error once the mutex is acquired.
+    /// this call will return an error once the mutex is acquired. The acquired
+    /// mutex guard will be contained in the returned error.
     ///
     /// # Panics
     ///
@@ -331,7 +426,8 @@ impl<T: ?Sized> Mutex<T> {
     ///
     /// If another user of this mutex panicked while holding the mutex, then
     /// this call will return the [`Poisoned`] error if the mutex would
-    /// otherwise be acquired.
+    /// otherwise be acquired. An acquired lock guard will be contained
+    /// in the returned error.
     ///
     /// If the mutex could not be acquired because it is already locked, then
     /// this call will return the [`WouldBlock`] error.
@@ -438,7 +534,8 @@ impl<T: ?Sized> Mutex<T> {
     /// # Errors
     ///
     /// If another user of this mutex panicked while holding the mutex, then
-    /// this call will return an error instead.
+    /// this call will return an error containing the the underlying data
+    /// instead.
     ///
     /// # Examples
     ///
@@ -465,7 +562,8 @@ impl<T: ?Sized> Mutex<T> {
     /// # Errors
     ///
     /// If another user of this mutex panicked while holding the mutex, then
-    /// this call will return an error instead.
+    /// this call will return an error containing a mutable reference to the
+    /// underlying data instead.
     ///
     /// # Examples
     ///