1 files changed, 27 insertions, 8 deletions
diff --git a/third_party/rust/fallible_collections/src/arc.rs b/third_party/rust/fallible_collections/src/arc.rs
index 282b8e5555..26a6ec9407 100644
--- a/third_party/rust/fallible_collections/src/arc.rs
+++ b/third_party/rust/fallible_collections/src/arc.rs
@@ -1,15 +1,20 @@
 //! Implement a Fallible Arc
+#[cfg(any(not(feature = "unstable"), feature = "rust_1_57"))]
 use super::FallibleBox;
 use super::TryClone;
-
 use crate::TryReserveError;
+
+#[cfg(any(not(feature = "unstable"), feature = "rust_1_57"))]
 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"
+#[cfg_attr(
+    any(not(feature = "unstable"), feature = "rust_1_57"),
+    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<T> {
     /// try creating a new Arc, returning a Result<Box<T>,
@@ -22,10 +27,24 @@ pub trait FallibleArc<T> {
 #[allow(deprecated)]
 impl<T> FallibleArc<T> for Arc<T> {
     fn try_new(t: T) -> Result<Self, TryReserveError> {
-        // doesn't work as the inner variable of arc are also stocked in the box
-
-        let b = <Box<T> as FallibleBox<T>>::try_new(t)?;
-        Ok(Arc::from(b))
+        #[cfg(any(not(feature = "unstable"), feature = "rust_1_57"))]
+        {
+            // doesn't work as the inner variable of arc are also stocked in the box
+            let b = <Box<T> as FallibleBox<T>>::try_new(t)?;
+            Ok(Arc::from(b))
+        }
+        #[cfg(all(feature = "unstable", not(feature = "rust_1_57")))]
+        {
+            use alloc::alloc::Layout;
+            use alloc::collections::TryReserveErrorKind;
+            Arc::try_new(t).map_err(|_e| {
+                TryReserveErrorKind::AllocError {
+                    layout: Layout::new::<Arc<T>>(), // This is bullshit
+                    non_exhaustive: (),
+                }
+                .into()
+            })
+        }
     }
 }