Update subtree/library to 2025-05-26

alloc/src/collections/btree/map.rs

@@ -1398,10 +1398,12 @@ impl<K, V, A: Allocator + Clone> BTreeMap<K, V, A> {
     }
 
     /// Creates an iterator that visits all elements (key-value pairs) in
-    /// ascending key order and uses a closure to determine if an element should
-    /// be removed. If the closure returns `true`, the element is removed from
-    /// the map and yielded. If the closure returns `false`, or panics, the
-    /// element remains in the map and will not be yielded.
+    /// ascending key order and uses a closure to determine if an element
+    /// should be removed.
+    ///
+    /// If the closure returns `true`, the element is removed from the map and
+    /// yielded. If the closure returns `false`, or panics, the element remains
+    /// in the map and will not be yielded.
     ///
     /// The iterator also lets you mutate the value of each element in the
     /// closure, regardless of whether you choose to keep or remove it.

alloc/src/collections/linked_list.rs

@@ -1124,20 +1124,20 @@ impl<T, A: Allocator> LinkedList<T, A> {
 
     /// Creates an iterator which uses a closure to determine if an element should be removed.
     ///
-    /// If the closure returns true, then the element is removed and yielded.
-    /// If the closure returns false, the element will remain in the list and will not be yielded
-    /// by the iterator.
+    /// If the closure returns `true`, the element is removed from the list and
+    /// yielded. If the closure returns `false`, or panics, the element remains
+    /// in the list and will not be yielded.
     ///
     /// If the returned `ExtractIf` is not exhausted, e.g. because it is dropped without iterating
     /// or the iteration short-circuits, then the remaining elements will be retained.
     /// Use `extract_if().for_each(drop)` if you do not need the returned iterator.
     ///
-    /// Note that `extract_if` lets you mutate every element in the filter closure, regardless of
-    /// whether you choose to keep or remove it.
+    /// The iterator also lets you mutate the value of each element in the
+    /// closure, regardless of whether you choose to keep or remove it.
     ///
     /// # Examples
     ///
-    /// Splitting a list into evens and odds, reusing the original list:
+    /// Splitting a list into even and odd values, reusing the original list:
     ///
     /// ```
     /// use std::collections::LinkedList;

alloc/src/collections/vec_deque/mod.rs

@@ -1312,6 +1312,8 @@ impl<T, A: Allocator> VecDeque<T, A> {
     ///
     /// If [`make_contiguous`] was previously called, all elements of the
     /// deque will be in the first slice and the second slice will be empty.
+    /// Otherwise, the exact split point depends on implementation details
+    /// and is not guaranteed.
     ///
     /// [`make_contiguous`]: VecDeque::make_contiguous
     ///
@@ -1326,12 +1328,18 @@ impl<T, A: Allocator> VecDeque<T, A> {
     /// deque.push_back(1);
     /// deque.push_back(2);
     ///
-    /// assert_eq!(deque.as_slices(), (&[0, 1, 2][..], &[][..]));
+    /// let expected = [0, 1, 2];
+    /// let (front, back) = deque.as_slices();
+    /// assert_eq!(&expected[..front.len()], front);
+    /// assert_eq!(&expected[front.len()..], back);
     ///
     /// deque.push_front(10);
     /// deque.push_front(9);
     ///
-    /// assert_eq!(deque.as_slices(), (&[9, 10][..], &[0, 1, 2][..]));
+    /// let expected = [9, 10, 0, 1, 2];
+    /// let (front, back) = deque.as_slices();
+    /// assert_eq!(&expected[..front.len()], front);
+    /// assert_eq!(&expected[front.len()..], back);
     /// ```
     #[inline]
     #[stable(feature = "deque_extras_15", since = "1.5.0")]
@@ -1347,6 +1355,8 @@ impl<T, A: Allocator> VecDeque<T, A> {
     ///
     /// If [`make_contiguous`] was previously called, all elements of the
     /// deque will be in the first slice and the second slice will be empty.
+    /// Otherwise, the exact split point depends on implementation details
+    /// and is not guaranteed.
     ///
     /// [`make_contiguous`]: VecDeque::make_contiguous
     ///
@@ -1363,9 +1373,22 @@ impl<T, A: Allocator> VecDeque<T, A> {
     /// deque.push_front(10);
     /// deque.push_front(9);
     ///
-    /// deque.as_mut_slices().0[0] = 42;
-    /// deque.as_mut_slices().1[0] = 24;
-    /// assert_eq!(deque.as_slices(), (&[42, 10][..], &[24, 1][..]));
+    /// // Since the split point is not guaranteed, we may need to update
+    /// // either slice.
+    /// let mut update_nth = |index: usize, val: u32| {
+    ///     let (front, back) = deque.as_mut_slices();
+    ///     if index > front.len() - 1 {
+    ///         back[index - front.len()] = val;
+    ///     } else {
+    ///         front[index] = val;
+    ///     }
+    /// };
+    ///
+    /// update_nth(0, 42);
+    /// update_nth(2, 24);
+    ///
+    /// let v: Vec<_> = deque.into();
+    /// assert_eq!(v, [42, 10, 24, 1]);
     /// ```
     #[inline]
     #[stable(feature = "deque_extras_15", since = "1.5.0")]

alloc/src/slice.rs

@@ -69,7 +69,7 @@ use crate::boxed::Box;
 use crate::vec::Vec;
 
 impl<T> [T] {
-    /// Sorts the slice, preserving initial order of equal elements.
+    /// Sorts the slice in ascending order, preserving initial order of equal elements.
     ///
     /// This sort is stable (i.e., does not reorder equal elements) and *O*(*n* \* log(*n*))
     /// worst-case.
@@ -137,7 +137,8 @@ impl<T> [T] {
         stable_sort(self, T::lt);
     }
 
-    /// Sorts the slice with a comparison function, preserving initial order of equal elements.
+    /// Sorts the slice in ascending order with a comparison function, preserving initial order of
+    /// equal elements.
     ///
     /// This sort is stable (i.e., does not reorder equal elements) and *O*(*n* \* log(*n*))
     /// worst-case.
@@ -197,7 +198,8 @@ impl<T> [T] {
         stable_sort(self, |a, b| compare(a, b) == Less);
     }
 
-    /// Sorts the slice with a key extraction function, preserving initial order of equal elements.
+    /// Sorts the slice in ascending order with a key extraction function, preserving initial order
+    /// of equal elements.
     ///
     /// This sort is stable (i.e., does not reorder equal elements) and *O*(*m* \* *n* \* log(*n*))
     /// worst-case, where the key function is *O*(*m*).
@@ -252,7 +254,8 @@ impl<T> [T] {
         stable_sort(self, |a, b| f(a).lt(&f(b)));
     }
 
-    /// Sorts the slice with a key extraction function, preserving initial order of equal elements.
+    /// Sorts the slice in ascending order with a key extraction function, preserving initial order
+    /// of equal elements.
     ///
     /// This sort is stable (i.e., does not reorder equal elements) and *O*(*m* \* *n* + *n* \*
     /// log(*n*)) worst-case, where the key function is *O*(*m*).

alloc/src/str.rs

@@ -320,6 +320,7 @@ impl str {
     /// ```
     #[cfg(not(no_global_oom_handling))]
     #[rustc_allow_incoherent_impl]
+    #[doc(alias = "replace_first")]
     #[must_use = "this returns the replaced string as a new allocation, \
                   without modifying the original"]
     #[stable(feature = "str_replacen", since = "1.16.0")]

alloc/src/vec/mod.rs

@@ -3648,11 +3648,11 @@ impl<T, A: Allocator> Vec<T, A> {
         Splice { drain: self.drain(range), replace_with: replace_with.into_iter() }
     }
 
-    /// Creates an iterator which uses a closure to determine if element in the range should be removed.
+    /// Creates an iterator which uses a closure to determine if an element in the range should be removed.
     ///
-    /// If the closure returns true, then the element is removed and yielded.
-    /// If the closure returns false, the element will remain in the vector and will not be yielded
-    /// by the iterator.
+    /// If the closure returns `true`, the element is removed from the vector
+    /// and yielded. If the closure returns `false`, or panics, the element
+    /// remains in the vector and will not be yielded.
     ///
     /// Only elements that fall in the provided range are considered for extraction, but any elements
     /// after the range will still have to be moved if any element has been extracted.
@@ -3692,16 +3692,16 @@ impl<T, A: Allocator> Vec<T, A> {
     /// But `extract_if` is easier to use. `extract_if` is also more efficient,
     /// because it can backshift the elements of the array in bulk.
     ///
-    /// Note that `extract_if` also lets you mutate the elements passed to the filter closure,
-    /// regardless of whether you choose to keep or remove them.
+    /// The iterator also lets you mutate the value of each element in the
+    /// closure, regardless of whether you choose to keep or remove it.
     ///
     /// # Panics
     ///
     /// If `range` is out of bounds.
     ///
     /// # Examples
     ///
-    /// Splitting an array into evens and odds, reusing the original allocation:
+    /// Splitting a vector into even and odd values, reusing the original vector:
     ///
     /// ```
     /// let mut numbers = vec![1, 2, 3, 4, 5, 6, 8, 9, 11, 13, 14, 15];

core/src/array/mod.rs

@@ -588,7 +588,7 @@ impl<T, const N: usize> [T; N] {
     /// Returns a mutable slice containing the entire array. Equivalent to
     /// `&mut s[..]`.
     #[stable(feature = "array_as_slice", since = "1.57.0")]
-    #[rustc_const_unstable(feature = "const_array_as_mut_slice", issue = "133333")]
+    #[rustc_const_stable(feature = "const_array_as_mut_slice", since = "CURRENT_RUSTC_VERSION")]
     pub const fn as_mut_slice(&mut self) -> &mut [T] {
         self
     }

core/src/convert/mod.rs

@@ -575,7 +575,7 @@ pub trait Into<T>: Sized {
 #[rustc_diagnostic_item = "From"]
 #[stable(feature = "rust1", since = "1.0.0")]
 #[rustc_on_unimplemented(on(
-    all(_Self = "&str", T = "alloc::string::String"),
+    all(Self = "&str", T = "alloc::string::String"),
     note = "to coerce a `{T}` into a `{Self}`, use `&*` as a prefix",
 ))]
 #[doc(search_unbox)]

core/src/ffi/c_str.rs

@@ -511,13 +511,8 @@ impl CStr {
     /// # Examples
     ///
     /// ```
-    /// use std::ffi::CStr;
-    ///
-    /// let cstr = CStr::from_bytes_with_nul(b"foo\0").unwrap();
-    /// assert_eq!(cstr.count_bytes(), 3);
-    ///
-    /// let cstr = CStr::from_bytes_with_nul(b"\0").unwrap();
-    /// assert_eq!(cstr.count_bytes(), 0);
+    /// assert_eq!(c"foo".count_bytes(), 3);
+    /// assert_eq!(c"".count_bytes(), 0);
     /// ```
     #[inline]
     #[must_use]
@@ -533,19 +528,8 @@ impl CStr {
     /// # Examples
     ///
     /// ```
-    /// use std::ffi::CStr;
-    /// # use std::ffi::FromBytesWithNulError;
-    ///
-    /// # fn main() { test().unwrap(); }
-    /// # fn test() -> Result<(), FromBytesWithNulError> {
-    /// let cstr = CStr::from_bytes_with_nul(b"foo\0")?;
-    /// assert!(!cstr.is_empty());
-    ///
-    /// let empty_cstr = CStr::from_bytes_with_nul(b"\0")?;
-    /// assert!(empty_cstr.is_empty());
+    /// assert!(!c"foo".is_empty());
     /// assert!(c"".is_empty());
-    /// # Ok(())
-    /// # }
     /// ```
     #[inline]
     #[stable(feature = "cstr_is_empty", since = "1.71.0")]
@@ -569,10 +553,7 @@ impl CStr {
     /// # Examples
     ///
     /// ```
-    /// use std::ffi::CStr;
-    ///
-    /// let cstr = CStr::from_bytes_with_nul(b"foo\0").expect("CStr::from_bytes_with_nul failed");
-    /// assert_eq!(cstr.to_bytes(), b"foo");
+    /// assert_eq!(c"foo".to_bytes(), b"foo");
     /// ```
     #[inline]
     #[must_use = "this returns the result of the operation, \
@@ -598,10 +579,7 @@ impl CStr {
     /// # Examples
     ///
     /// ```
-    /// use std::ffi::CStr;
-    ///
-    /// let cstr = CStr::from_bytes_with_nul(b"foo\0").expect("CStr::from_bytes_with_nul failed");
-    /// assert_eq!(cstr.to_bytes_with_nul(), b"foo\0");
+    /// assert_eq!(c"foo".to_bytes_with_nul(), b"foo\0");
     /// ```
     #[inline]
     #[must_use = "this returns the result of the operation, \
@@ -623,10 +601,8 @@ impl CStr {
     ///
     /// ```
     /// #![feature(cstr_bytes)]
-    /// use std::ffi::CStr;
     ///
-    /// let cstr = CStr::from_bytes_with_nul(b"foo\0").expect("CStr::from_bytes_with_nul failed");
-    /// assert!(cstr.bytes().eq(*b"foo"));
+    /// assert!(c"foo".bytes().eq(*b"foo"));
     /// ```
     #[inline]
     #[unstable(feature = "cstr_bytes", issue = "112115")]
@@ -645,10 +621,7 @@ impl CStr {
     /// # Examples
     ///
     /// ```
-    /// use std::ffi::CStr;
-    ///
-    /// let cstr = CStr::from_bytes_with_nul(b"foo\0").expect("CStr::from_bytes_with_nul failed");
-    /// assert_eq!(cstr.to_str(), Ok("foo"));
+    /// assert_eq!(c"foo".to_str(), Ok("foo"));
     /// ```
     #[stable(feature = "cstr_to_str", since = "1.4.0")]
     #[rustc_const_stable(feature = "const_cstr_methods", since = "1.72.0")]

core/src/ffi/mod.rs

@@ -28,7 +28,7 @@ pub mod c_str;
     issue = "44930",
     reason = "the `c_variadic` feature has not been properly tested on all supported platforms"
 )]
-pub use self::va_list::{VaList, VaListImpl};
+pub use self::va_list::{VaArgSafe, VaList, VaListImpl};
 
 #[unstable(
     feature = "c_variadic",

core/src/ffi/primitives.rs

@@ -35,7 +35,7 @@ type_alias! { "c_float.md", c_float = f32; }
 type_alias! { "c_double.md", c_double = f64; }
 
 mod c_char_definition {
-    crate::cfg_match! {
+    crate::cfg_select! {
         // These are the targets on which c_char is unsigned. Usually the
         // signedness is the same for all target_os values on a given architecture
         // but there are some exceptions (see isSignedCharDefault() in clang).
@@ -133,7 +133,7 @@ mod c_char_definition {
 }
 
 mod c_long_definition {
-    crate::cfg_match! {
+    crate::cfg_select! {
         any(
             all(target_pointer_width = "64", not(windows)),
             // wasm32 Linux ABI uses 64-bit long
@@ -172,7 +172,7 @@ pub type c_ptrdiff_t = isize;
 pub type c_ssize_t = isize;
 
 mod c_int_definition {
-    crate::cfg_match! {
+    crate::cfg_select! {
         any(target_arch = "avr", target_arch = "msp430") => {
             pub(super) type c_int = i16;
             pub(super) type c_uint = u16;