1.11.1 (February 3rd, 2026)

• Fix integer overflow in BytesMut::reserve

1.11.0 (November 14th, 2025)

• Bump MSRV to 1.57 (#788)

Fixed

• fix: BytesMut only reuse if src has remaining (#803)
• Specialize BytesMut::put::<Bytes> (#793)
• Reserve capacity in BytesMut::put (#794)
• Change BytesMut::remaining_mut to use isize::MAX instead of usize::MAX (#795)

Internal changes

• Guarantee address in slice() for empty slices. (#780)
• Rename Vtable::to_* -> Vtable::into_* (#776)
• Fix latest clippy warnings (#787)
• Ignore BytesMut::freeze doctest on wasm (#790)
• Move drop_fn of from_owner into vtable (#801)

1.10.1 (March 5th, 2025)

Fixed

• Fix memory leak when using to_vec with Bytes::from_owner (#773)

1.10.0 (February 3rd, 2025)

Added

• Add feature to support platforms without atomic CAS (#467)
• try_get_* methods for Buf trait (#753)
• Implement Buf::chunks_vectored for Take (#617)
• Implement Buf::chunks_vectored for VecDeque<u8> (#708)

Fixed

• Remove incorrect guarantee for chunks_vectored (#754)
• Ensure that tests pass under panic=abort (#749)

1.9.0 (November 27, 2024)

Added

• Add Bytes::from_owner to enable externally-allocated memory (#742)

Documented

• Fix typo in Buf::chunk() comment (#744)

Internal changes

• Replace BufMut::put with BufMut::put_slice in Writer impl (#745)
• Rename hex_impl! to fmt_impl! and reuse it for fmt::Debug (#743)

1.8.0 (October 21, 2024)

• Guarantee address in split_off/split_to for empty slices (#740)

1.7.2 (September 17, 2024)

Fixed

• Fix default impl of Buf::{get_int, get_int_le} (#732)

Documented

• Fix double spaces in comments and doc comments (#731)

Internal changes

• Ensure BytesMut::advance reduces capacity (#728)

1.7.1 (August 1, 2024)

This release reverts the following change due to a regression:

• Reuse capacity when possible in <BytesMut as Buf>::advance impl (#698)

The revert can be found at #726.

Added

• Add conversion from Bytes to BytesMut (#695, #710)
• Add reclaim method without additional allocation (#686)

Documented

• Clarify how BytesMut::zeroed works (#714)
• Clarify the behavior of Buf::chunk (#717)

Changed

• Change length condition of BytesMut::truncate
• Reuse capacity when possible in <BytesMut as Buf>::advance impl (#698)
• Improve must_use suggestion of BytesMut::split (#699)

Internal changes

• Use ManuallyDrop instead of mem::forget (#678)
• Don't set len in BytesMut::reserve (#682)
• Optimize Bytes::copy_to_bytes (#688)
• Refactor BytesMut::truncate (#694)
• Refactor BytesMut::resize (#696)
• Reorder assertion in Bytes::split_to, Bytes::split_off (#689, #693)
• Use offset_from in more places (#705)
• Correct the wrong usage of IntoIter (#707)

This release fixes a bug where Bytes::is_unique returns incorrect values when the Bytes originates from a shared BytesMut. (#718)

Added

• Add Bytes::is_unique (#643)

Documented

• Fix changelog typo (#628)
• Fix some spelling mistakes (#633)
• Typo fix (#637)
• Fix broken links (#639)
• Add security policy (#649)

Internal changes

• Move comment to correct constant (#629)
• Various cleanup (#635)
• Simplify UninitSlice::as_uninit_slice_mut() logic (#644)
• Use self. instead of Self:: (#642)
• BytesMut: Assert alignment of Shared (#652)
• Remove unnecessary namespace qualifier (#660)
• Remove an unnecessary else branch (#662)
• Remove unreachable else branch (#661)
• make parameter mut in From<Vec> (#667)
• Restore commented tests (#665)
• Use sub instead of offset (#668)
• Calculate original capacity only if necessary (#666)
• set_vec_pos does not need a second parameter (#672)
• get_vec_pos: use &self instead of &mut self (#670)
• Refactor split_at/split_to (#663)
• Use Iterator from the prelude (#673)
• copy_to_bytes: Add panic section to docs (#676)
• Remove redundant reserve call (#674)
• Use ManuallyDrop instead of mem::forget (#675)

Added

• Add UninitSlice::{new,uninit} (#598, #599)
• Implement BufMut for &mut [MaybeUninit<u8>] (#597)

Changed

• Mark BytesMut::extend_from_slice as inline (#595)

Added

• Make IntoIter constructor public (#581)

Fixed

• Avoid large reallocations when freezing BytesMut (#592)

Documented

• Document which functions require std (#591)
• Fix duplicate "the the" typos (#585)

Added

• Rename and expose BytesMut::spare_capacity_mut (#572)
• Implement native-endian get and put functions for Buf and BufMut (#576)

Fixed

• Don't have important data in unused capacity when calling reserve (#563)

Documented

• Bytes::new etc should return Self not Bytes (#568)

Fixed

• Fix unbounded memory growth when using reserve (#560)

Added

• Add BytesMut::zeroed (#517)
• Implement Extend<Bytes> for BytesMut (#527)
• Add conversion from BytesMut to Vec<u8> (#543, #554)
• Add conversion from Bytes to Vec<u8> (#547)
• Add UninitSlice::as_uninit_slice_mut() (#548)
• Add const to Bytes::{len,is_empty} (#514)

Changed

• Reuse vector in BytesMut::reserve (#539, #544)

Fixed

• Make miri happy (#515, #523, #542, #545, #553)
• Make tsan happy (#541)
• Fix remaining_mut() on chain (#488)
• Fix amortized asymptotics of BytesMut (#555)

Documented

• Redraw layout diagram with box drawing characters (#539)
• Clarify BytesMut::unsplit docs (#535)

Added

• BufMut::put_bytes(self, val, cnt) (#487)
• Implement From<Box<[u8]>> for Bytes (#504)

Changed

• Override put_slice for &mut [u8] (#483)
• Panic on integer overflow in Chain::remaining (#482)
• Add inline tags to UninitSlice methods (#443)
• Override copy_to_bytes for Chain and Take (#481)
• Keep capacity when unsplit on empty other buf (#502)

Documented

• Clarify BufMut allocation guarantees (#501)
• Clarify BufMut::put_int behavior (#486)
• Clarify actions of clear and truncate. (#508)

Changed

• mark Vec::put_slice with #[inline] (#459)

Fixed

• Fix deprecation warning (#457)
• use Box::into_raw instead of mem::forget-in-disguise (#458)

Changed

• Rename Buf/BufMut methods bytes() and bytes_mut() to chunk() and chunk_mut() (#450)

Removed

• remove unused Buf implementation. (#449)

API polish in preparation for a 1.0 release.

Changed

• BufMut is now an unsafe trait (#432).
• BufMut::bytes_mut() returns &mut UninitSlice, a type owned by bytes to avoid undefined behavior (#433).
• Buf::copy_to_bytes(len) replaces Buf::into_bytes() (#439).
• Buf/BufMut utility methods are moved onto the trait and *Ext traits are removed (#431).

Removed

• BufMut::bytes_vectored_mut() (#430).
• new methods on combinator types (#434).

• Improve BytesMut to reuse buffer when fully advanced.
• Mark BytesMut::{as_mut, set_len} with #[inline].
• Relax synchronization when cloning in shared vtable of Bytes.
• Move loom to dev-dependencies.

Added

• Allow using the serde feature in no_std environments (#385).

Fix

• Fix BufMut::advance_mut to panic if advanced passed the capacity (#354)..
• Fix BytesMut::freeze ignoring amount previously advanced (#352).

Added

• Make Bytes::new a const fn.
• Add From<BytesMut> for Bytes.

Fix

• Fix reversed arguments in PartialOrd for Bytes.
• Fix Bytes::truncate losing original capacity when repr is an unshared Vec.
• Fix Bytes::from(Vec) when allocator gave Vec a pointer with LSB set.
• Fix panic in Bytes::slice_ref if argument is an empty slice.

Added

• must_use attributes to split, split_off, and split_to methods (#337).

Fix

• Potential freeing of a null pointer in Bytes when constructed with an empty Vec<u8> (#341, #342).
• Calling Bytes::truncate with a size large than the length will no longer clear the Bytes (#333).

Added

• Limit methods into_inner, get_ref, get_mut, limit, and set_limit (#325).

Fix

• Growth documentation for BytesMut (#321)

Fix

• Potential overflow in copy_to_slice

Changed

• Increased minimum supported Rust version to 1.39.
• Bytes is now a "trait object", allowing for custom allocation strategies (#298)
• BytesMut implicitly grows internal storage. remaining_mut() returns usize::MAX (#316).
• BufMut::bytes_mut returns &mut [MaybeUninit<u8>] to reflect the unknown initialization state (#305).
• Buf / BufMut implementations for &[u8] and &mut [u8] respectively (#261).
• Move Buf / BufMut "extra" functions to an extension trait (#306).
• BufMutExt::limit (#309).
• Bytes::slice takes a RangeBounds argument (#265).
• Bytes::from_static is now a const fn (#311).
• A multitude of smaller performance optimizations.

Added

• no_std support (#281).
• get_*, put_*, get_*_le, and put_*le accessors for handling byte order.
• BorrowMut implementation for BytesMut (#185).

Removed

• IntoBuf (#288).
• Buf implementation for &str (#301).
• byteorder dependency (#280).
• iovec dependency, use std::IoSlice instead (#263).
• optional either dependency (#315).
• optional i128 feature -- now available on stable. (#276).

Added

• Implement FromIterator<&'a u8> for BytesMut/Bytes (#244).
• Implement Buf for VecDeque (#249).

• Use raw pointers for potentially racy loads (#233).
• Implement BufRead for buf::Reader (#232).
• Documentation tweaks (#234).

• impl Buf and BufMut for Either (#225).
• Add Bytes::slice_ref (#208).

• Add 128 bit number support behind a feature flag (#209).
• Implement IntoBuf for &mut [u8]

• Fix panic in BytesMut FromIterator implementation.
• Bytes: Recycle space when reserving space in vec mode (#197).
• Bytes: Add resize fn (#203).

• Make Buf and BufMut usable as trait objects (#186).
• impl BorrowMut for BytesMut (#185).
• Improve accessor performance (#195).

• Implement FromIterator for Bytes/BytesMut (#148).
• Add advance fn to Bytes/BytesMut (#166).
• Add unsplit fn to BytesMut (#162, #173).
• Improvements to Bytes split fns (#92).

• Fix range bug in Take::bytes
• Misc performance improvements
• Add extra PartialEq implementations.
• Add Bytes::with_capacity
• Implement AsMut[u8] for BytesMut

• Add serde support behind feature flag
• Add extend_from_slice on Bytes and BytesMut
• Add truncate and clear on Bytes
• Misc additional std trait implementations
• Misc performance improvements

• Fix Vec::advance_mut bug
• Bump minimum Rust version to 1.15
• Misc performance tweaks

• Misc performance tweaks
• Improved Debug implementation for Bytes
• Avoid some incorrect assert panics

• Expose buf module and have most types available from there vs. root.
• Implement IntoBuf for T: Buf.
• Add FromBuf and Buf::collect.
• Add iterator adapter for Buf.
• Add scatter/gather support to Buf and BufMut.
• Add Buf::chain.
• Reduce allocations on repeated calls to BytesMut::reserve.
• Implement Debug for more types.
• Remove Source in favor of IntoBuf.
• Implement Extend for BytesMut.

• Initial release