From 26a029d407be480d791972afb5975cf62c9360a6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Fri, 19 Apr 2024 02:47:55 +0200 Subject: Adding upstream version 124.0.1. Signed-off-by: Daniel Baumann --- third_party/rust/fallible_collections/src/arc.rs | 52 ++++++++++++++++++++++++ 1 file changed, 52 insertions(+) create mode 100644 third_party/rust/fallible_collections/src/arc.rs (limited to 'third_party/rust/fallible_collections/src/arc.rs') diff --git a/third_party/rust/fallible_collections/src/arc.rs b/third_party/rust/fallible_collections/src/arc.rs new file mode 100644 index 0000000000..282b8e5555 --- /dev/null +++ b/third_party/rust/fallible_collections/src/arc.rs @@ -0,0 +1,52 @@ +//! Implement a Fallible Arc +use super::FallibleBox; +use super::TryClone; + +use crate::TryReserveError; +use alloc::boxed::Box; +use alloc::sync::Arc; + +/// trait to implement Fallible Arc +#[deprecated( + since = "0.3.1", + note = "⚠️️️this function is not completely fallible, it can panic !, see [issue](https://github.com/vcombey/fallible_collections/issues/13). help wanted" +)] +pub trait FallibleArc { + /// try creating a new Arc, returning a Result, + /// TryReserveError> if allocation failed + fn try_new(t: T) -> Result + where + Self: Sized; +} + +#[allow(deprecated)] +impl FallibleArc for Arc { + fn try_new(t: T) -> Result { + // doesn't work as the inner variable of arc are also stocked in the box + + let b = as FallibleBox>::try_new(t)?; + Ok(Arc::from(b)) + } +} + +/// Just a TryClone boilerplate for Arc +impl TryClone for Arc { + fn try_clone(&self) -> Result { + Ok(self.clone()) + } +} + +#[cfg(test)] +mod test { + #[test] + fn fallible_rc() { + use std::sync::Arc; + + let mut x = Arc::new(3); + *Arc::get_mut(&mut x).unwrap() = 4; + assert_eq!(*x, 4); + + let _y = Arc::clone(&x); + assert!(Arc::get_mut(&mut x).is_none()); + } +} -- cgit v1.2.3