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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
commit | 36d22d82aa202bb199967e9512281e9a53db42c9 (patch) | |
tree | 105e8c98ddea1c1e4784a60a5a6410fa416be2de /third_party/rust/fallible_collections/src/rc.rs | |
parent | Initial commit. (diff) | |
download | firefox-esr-upstream.tar.xz firefox-esr-upstream.zip |
Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'third_party/rust/fallible_collections/src/rc.rs')
-rw-r--r-- | third_party/rust/fallible_collections/src/rc.rs | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/third_party/rust/fallible_collections/src/rc.rs b/third_party/rust/fallible_collections/src/rc.rs new file mode 100644 index 0000000000..4fc16dc2af --- /dev/null +++ b/third_party/rust/fallible_collections/src/rc.rs @@ -0,0 +1,35 @@ +//! Implement a Fallible Rc +use super::FallibleBox; +use crate::TryReserveError; +use alloc::boxed::Box; +use alloc::rc::Rc; +/// trait to implement Fallible Rc +pub trait FallibleRc<T> { + /// try creating a new Rc, returning a Result<Box<T>, + /// TryReserveError> if allocation failed + fn try_new(t: T) -> Result<Self, TryReserveError> + where + Self: Sized; +} + +impl<T> FallibleRc<T> for Rc<T> { + fn try_new(t: T) -> Result<Self, TryReserveError> { + let b = <Box<T> as FallibleBox<T>>::try_new(t)?; + Ok(Rc::from(b)) + } +} + +#[cfg(test)] +mod test { + #[test] + fn fallible_rc() { + use std::rc::Rc; + + let mut x = Rc::new(3); + *Rc::get_mut(&mut x).unwrap() = 4; + assert_eq!(*x, 4); + + let _y = Rc::clone(&x); + assert!(Rc::get_mut(&mut x).is_none()); + } +} |