Auto merge of #122256 - Nadrieril:rollup-rc232xh, r=Nadrieril

Rollup of 8 pull requests

Successful merges:

 - #99153 (Add Read Impl for &Stdin)
 - #114655 (Make `impl<Fd: AsFd>` impl take `?Sized`)
 - #120504 (Vec::try_with_capacity)
 - #121280 (Implement MaybeUninit::fill{,_with,_from})
 - #121403 (impl From<TryReserveError> for io::Error)
 - #121526 (on the fly type casting for `build.rustc` and `build.cargo`)
 - #121584 (bump itertools to 0.12)
 - #121711 (Implement junction_point)

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

1 files changed, 34 insertions, 0 deletions

diff --git a/library/alloc/src/vec/mod.rs b/library/alloc/src/vec/mod.rs
index c0e934b3b1f..f2f42e63d6b 100644
--- a/library/alloc/src/vec/mod.rs
+++ b/library/alloc/src/vec/mod.rs
@@ -481,6 +481,22 @@ impl<T> Vec<T> {
         Self::with_capacity_in(capacity, Global)
     }
 
+    /// Constructs a new, empty `Vec<T>` with at least the specified capacity.
+    ///
+    /// The vector will be able to hold at least `capacity` elements without
+    /// reallocating. This method is allowed to allocate for more elements than
+    /// `capacity`. If `capacity` is 0, the vector will not allocate.
+    ///
+    /// # Errors
+    ///
+    /// Returns an error if the capacity exceeds `isize::MAX` _bytes_,
+    /// or if the allocator reports allocation failure.
+    #[inline]
+    #[unstable(feature = "try_with_capacity", issue = "91913")]
+    pub fn try_with_capacity(capacity: usize) -> Result<Self, TryReserveError> {
+        Self::try_with_capacity_in(capacity, Global)
+    }
+
     /// Creates a `Vec<T>` directly from a pointer, a length, and a capacity.
     ///
     /// # Safety
@@ -672,6 +688,24 @@ impl<T, A: Allocator> Vec<T, A> {
         Vec { buf: RawVec::with_capacity_in(capacity, alloc), len: 0 }
     }
 
+    /// Constructs a new, empty `Vec<T, A>` with at least the specified capacity
+    /// with the provided allocator.
+    ///
+    /// The vector will be able to hold at least `capacity` elements without
+    /// reallocating. This method is allowed to allocate for more elements than
+    /// `capacity`. If `capacity` is 0, the vector will not allocate.
+    ///
+    /// # Errors
+    ///
+    /// Returns an error if the capacity exceeds `isize::MAX` _bytes_,
+    /// or if the allocator reports allocation failure.
+    #[inline]
+    #[unstable(feature = "allocator_api", issue = "32838")]
+    // #[unstable(feature = "try_with_capacity", issue = "91913")]
+    pub fn try_with_capacity_in(capacity: usize, alloc: A) -> Result<Self, TryReserveError> {
+        Ok(Vec { buf: RawVec::try_with_capacity_in(capacity, alloc)?, len: 0 })
+    }
+
     /// Creates a `Vec<T, A>` directly from a pointer, a length, a capacity,
     /// and an allocator.
     ///