diff options
Diffstat (limited to 'library/alloc/src/vec')
| -rw-r--r-- | library/alloc/src/vec/mod.rs | 34 |
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. /// |
