[trusty-std] Add fallible vector push
Adds a a fallible push method to Vec.
Test: build.py
Bug: 193278128
Change-Id: Iac68b17cee9ffcd456996d0e56b6cadfa4361784
diff --git a/lib/trusty-std/src/alloc.rs b/lib/trusty-std/src/alloc.rs
index 67cdfbd..6972d8e 100644
--- a/lib/trusty-std/src/alloc.rs
+++ b/lib/trusty-std/src/alloc.rs
@@ -20,11 +20,15 @@
#![allow(unused_unsafe)]
use crate::util::{abort_internal, print_internal};
+use alloc::collections::TryReserveError;
use core::cmp;
use core::intrinsics;
use core::ptr::{self, NonNull};
-pub use alloc::alloc::AllocError;
+#[doc(inline)]
+pub use alloc::alloc::*;
+
+#[doc(inline)]
pub use alloc::vec::Vec;
/// A value-to-value conversion that may fallibly allocate. The opposite of
@@ -84,8 +88,22 @@
}
}
-#[doc(inline)]
-pub use alloc::alloc::*;
+/// Temporary trait to implement the future fallible API for [`Vec`].
+// This should be removed when https://github.com/rust-lang/rust/pull/91559 or a
+// similar change is available.
+pub trait FallibleVec<T> {
+ /// Tries to append `value` to the end of the vector, returning Err if it
+ /// cannot allocate space for the expanded vector.
+ fn try_push(&mut self, value: T) -> Result<(), TryReserveError>;
+}
+
+impl<T> FallibleVec<T> for Vec<T> {
+ fn try_push(&mut self, value: T) -> Result<(), TryReserveError> {
+ self.try_reserve(self.len() + 1)?;
+ self.push(value);
+ Ok(())
+ }
+}
/*
* We provide the implementation of std::alloc::System here so that we don't
