03989773a9
Make `try_with_capacity`, `try_push`, and `try_extend_from_slice` methods available in `Vec` even though it doesn't implement them. It is implemented with `try_reserve` and `push_within_capacity`. This is in preparation for switching to the upstream `alloc` crate. Reviewed-by: Benno Lossin <benno.lossin@proton.me> Suggested-by: Gary Guo <gary@garyguo.net> Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com> Link: https://lore.kernel.org/r/20240328013603.206764-3-wedsonaf@gmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
48 lines
1.4 KiB
Rust
48 lines
1.4 KiB
Rust
// SPDX-License-Identifier: GPL-2.0
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//! Extensions to [`Vec`] for fallible allocations.
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use alloc::{collections::TryReserveError, vec::Vec};
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use core::result::Result;
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/// Extensions to [`Vec`].
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pub trait VecExt<T>: Sized {
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/// Creates a new [`Vec`] instance with at least the given capacity.
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fn try_with_capacity(capacity: usize) -> Result<Self, TryReserveError>;
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/// Appends an element to the back of the [`Vec`] instance.
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fn try_push(&mut self, v: T) -> Result<(), TryReserveError>;
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/// Pushes clones of the elements of slice into the [`Vec`] instance.
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fn try_extend_from_slice(&mut self, other: &[T]) -> Result<(), TryReserveError>
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where
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T: Clone;
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}
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impl<T> VecExt<T> for Vec<T> {
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fn try_with_capacity(capacity: usize) -> Result<Self, TryReserveError> {
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let mut v = Vec::new();
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v.try_reserve(capacity)?;
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Ok(v)
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}
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fn try_push(&mut self, v: T) -> Result<(), TryReserveError> {
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if let Err(retry) = self.push_within_capacity(v) {
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self.try_reserve(1)?;
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let _ = self.push_within_capacity(retry);
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}
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Ok(())
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}
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fn try_extend_from_slice(&mut self, other: &[T]) -> Result<(), TryReserveError>
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where
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T: Clone,
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{
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self.try_reserve(other.len())?;
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for item in other {
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self.try_push(item.clone())?;
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}
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Ok(())
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}
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}
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