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-rw-r--r--rust/common/src/zeroable.rs18
1 files changed, 18 insertions, 0 deletions
diff --git a/rust/common/src/zeroable.rs b/rust/common/src/zeroable.rs
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+// SPDX-License-Identifier: GPL-2.0-or-later
+
+//! Defines a trait for structs that can be safely initialized with zero bytes.
+
+/// Encapsulates the requirement that
+/// `MaybeUninit::<Self>::zeroed().assume_init()` does not cause undefined
+/// behavior.
+///
+/// # Safety
+///
+/// Do not add this trait to a type unless all-zeroes is a valid value for the
+/// type. In particular, raw pointers can be zero, but references and
+/// `NonNull<T>` cannot.
+pub unsafe trait Zeroable: Default {
+ /// Return a value of Self whose memory representation consists of all
+ /// zeroes, with the possible exclusion of padding bytes.
+ const ZERO: Self = unsafe { ::core::mem::MaybeUninit::<Self>::zeroed().assume_init() };
+}