diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index ffffc6e5..995e0f76 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -23,7 +23,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        rust: [stable, beta, nightly, 1.75.0]
+        rust: [stable, beta, nightly, 1.85.0]
 
     steps:
       - uses: actions/checkout@v6
diff --git a/Cargo.lock b/Cargo.lock
index f1bb3c09..415abbc7 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1,6 +1,6 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
-version = 3
+version = 4
 
 [[package]]
 name = "anstream"
@@ -174,9 +174,9 @@ dependencies = [
 
 [[package]]
 name = "hashbrown"
-version = "0.16.1"
+version = "0.17.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "841d1cc9bed7f9236f321df977030373f4a4163ae1a7dbfe1a51a2c1a51d9100"
+checksum = "4f467dd6dccf739c208452f8014c75c18bb8301b050ad1cfb27153803edb0f51"
 dependencies = [
  "foldhash",
 ]
diff --git a/Cargo.toml b/Cargo.toml
index 7833ce94..e0d116c5 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -9,8 +9,8 @@ repository = "https://github.com/bmwill/diffy"
 readme = "README.md"
 keywords = ["diff", "patch", "merge"]
 categories = ["text-processing"]
-rust-version = "1.75.0"
-edition = "2021"
+rust-version = "1.85.0"
+edition = "2024"
 
 [package.metadata.docs.rs]
 # To build locally:
@@ -35,7 +35,7 @@ binary = ["dep:zlib-rs"]
 color = ["dep:anstyle"]
 
 [dependencies]
-hashbrown = { version = "0.16.1", default-features = false, features = ["default-hasher"] }
+hashbrown = { version = "0.17.0", default-features = false, features = ["default-hasher"] }
 anstyle = { version = "1.0.13", default-features = false, optional = true }
 zlib-rs = { version = "0.6.3", optional = true, default-features = false, features = ["c-allocator"] }
 
diff --git a/examples/patch_formatter.rs b/examples/patch_formatter.rs
index 4a1a90cf..76d3dc7a 100644
--- a/examples/patch_formatter.rs
+++ b/examples/patch_formatter.rs
@@ -1,5 +1,5 @@
-use diffy::create_patch;
 use diffy::PatchFormatter;
+use diffy::create_patch;
 
 fn main() {
     let original = "first line\nlast line";
diff --git a/src/apply.rs b/src/apply.rs
index 779cb2be..ad8adafb 100644
--- a/src/apply.rs
+++ b/src/apply.rs
@@ -20,9 +20,7 @@ impl fmt::Display for ApplyError {
     }
 }
 
-#[cfg(feature = "std")]
-#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
-impl std::error::Error for ApplyError {}
+impl core::error::Error for ApplyError {}
 
 #[derive(Debug)]
 enum ImageLine<'a, T: ?Sized> {
@@ -60,8 +58,8 @@ impl<T: ?Sized> Clone for ImageLine<'_, T> {
 /// Apply a `Patch` to a base image
 ///
 /// ```
-/// use diffy::apply;
 /// use diffy::Patch;
+/// use diffy::apply;
 ///
 /// let s = "\
 /// --- a/ideals
@@ -112,8 +110,8 @@ pub fn apply(base_image: &str, patch: &Patch<'_, str>) -> Result<String, ApplyEr
 /// # Examples
 ///
 /// ```
-/// use diffy::apply_bytes;
 /// use diffy::Patch;
+/// use diffy::apply_bytes;
 ///
 /// let patch = Patch::from_bytes(
 ///     b"\
diff --git a/src/binary/base85.rs b/src/binary/base85.rs
index 600adf6b..2eb6ea88 100644
--- a/src/binary/base85.rs
+++ b/src/binary/base85.rs
@@ -46,9 +46,7 @@ impl fmt::Display for Base85Error {
     }
 }
 
-#[cfg(feature = "std")]
-#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
-impl std::error::Error for Base85Error {}
+impl core::error::Error for Base85Error {}
 
 /// Decodes a Base85 string to the provided output.
 ///
@@ -92,7 +90,8 @@ pub fn decode_into(input: &[u8], output: &mut impl Extend<u8>) -> Result<(), Bas
 /// Callers encoding data where the byte count isn't a multiple of 4
 /// must handle padding at a higher level.
 /// For example, via a length indicator in Git binary patch format.
-#[allow(dead_code)] // will be used for patch formatting
+// will be used for patch formatting
+#[cfg_attr(not(test), expect(dead_code))]
 pub fn encode_into(input: &[u8], output: &mut impl Extend<char>) -> Result<(), Base85Error> {
     if input.len() % 4 != 0 {
         return Err(Base85Error::InvalidLength);
diff --git a/src/binary/delta.rs b/src/binary/delta.rs
index fb6f2fee..48e44529 100644
--- a/src/binary/delta.rs
+++ b/src/binary/delta.rs
@@ -221,9 +221,7 @@ impl fmt::Display for DeltaError {
     }
 }
 
-#[cfg(feature = "std")]
-#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
-impl std::error::Error for DeltaError {}
+impl core::error::Error for DeltaError {}
 
 #[cfg(test)]
 mod tests {
diff --git a/src/binary/mod.rs b/src/binary/mod.rs
index 07b9f4f5..49f084e9 100644
--- a/src/binary/mod.rs
+++ b/src/binary/mod.rs
@@ -291,9 +291,7 @@ impl fmt::Display for BinaryPatchParseError {
     }
 }
 
-#[cfg(feature = "std")]
-#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
-impl std::error::Error for BinaryPatchParseError {}
+impl core::error::Error for BinaryPatchParseError {}
 
 #[cfg(feature = "binary")]
 impl From<base85::Base85Error> for BinaryPatchParseError {
@@ -320,8 +318,6 @@ impl From<BinaryPatchParseErrorKind> for BinaryPatchParseError {
 #[non_exhaustive]
 pub(crate) enum BinaryPatchParseErrorKind {
     /// Missing or invalid "GIT binary patch" header.
-    // TODO: Switch to #[expect(dead_code)] when MSRV >= 1.81
-    #[cfg_attr(not(feature = "binary"), allow(dead_code))]
     InvalidHeader,
 
     /// First binary block (forward) not found.
@@ -331,13 +327,11 @@ pub(crate) enum BinaryPatchParseErrorKind {
     MissingReverseBlock,
 
     /// No binary data available (marker-only patch).
-    // TODO: Switch to #[expect(dead_code)] when MSRV >= 1.81
-    #[cfg_attr(not(feature = "binary"), allow(dead_code))]
+    #[cfg_attr(not(feature = "binary"), expect(dead_code))]
     NoBinaryData,
 
     /// Invalid line length indicator in Base85 data.
-    // TODO: Switch to #[expect(dead_code)] when MSRV >= 1.81
-    #[cfg_attr(not(feature = "binary"), allow(dead_code))]
+    #[cfg_attr(not(feature = "binary"), expect(dead_code))]
     InvalidLineLengthIndicator,
 
     /// Base85 decoding failed.
diff --git a/src/diff/cleanup.rs b/src/diff/cleanup.rs
index 3b1b6dca..f323dcc3 100644
--- a/src/diff/cleanup.rs
+++ b/src/diff/cleanup.rs
@@ -4,7 +4,6 @@ use alloc::vec::Vec;
 
 // Walks through all edits and shifts them up and then down, trying to see if they run into similar
 // edits which can be merged
-#[allow(clippy::needless_lifetimes)]
 pub fn compact<'a, 'b, T: ?Sized + SliceLike>(diffs: &mut Vec<DiffRange<'a, 'b, T>>) {
     // First attempt to compact all Deletions
     let mut pointer = 0;
@@ -29,7 +28,6 @@ pub fn compact<'a, 'b, T: ?Sized + SliceLike>(diffs: &mut Vec<DiffRange<'a, 'b,
 }
 
 // Attempts to shift the Insertion or Deletion at location `pointer` as far upwards as possible.
-#[allow(clippy::needless_lifetimes)]
 fn shift_diff_up<'a, 'b, T: ?Sized + SliceLike>(
     diffs: &mut Vec<DiffRange<'a, 'b, T>>,
     mut pointer: usize,
@@ -131,7 +129,6 @@ fn shift_diff_up<'a, 'b, T: ?Sized + SliceLike>(
 }
 
 // Attempts to shift the Insertion or Deletion at location `pointer` as far downwards as possible.
-#[allow(clippy::needless_lifetimes)]
 fn shift_diff_down<'a, 'b, T: ?Sized + SliceLike>(
     diffs: &mut Vec<DiffRange<'a, 'b, T>>,
     mut pointer: usize,
diff --git a/src/diff/mod.rs b/src/diff/mod.rs
index 861f638e..b62e4406 100644
--- a/src/diff/mod.rs
+++ b/src/diff/mod.rs
@@ -17,7 +17,6 @@ mod myers;
 mod tests;
 
 // TODO determine if this should be exposed in the public API
-#[allow(dead_code)]
 #[derive(Debug, PartialEq, Eq)]
 enum Diff<'a, T: ?Sized> {
     Equal(&'a T),
@@ -117,7 +116,7 @@ impl DiffOptions {
     /// produce a prettier diff by reducing the number of edited blocks by shifting and merging
     /// edit blocks.
     // TODO determine if this should be exposed in the public API
-    #[allow(dead_code)]
+    #[expect(dead_code)]
     fn set_compact(&mut self, compact: bool) -> &mut Self {
         self.compact = compact;
         self
@@ -146,7 +145,6 @@ impl DiffOptions {
     }
 
     // TODO determine if this should be exposed in the public API
-    #[allow(dead_code)]
     fn diff<'a>(&self, original: &'a str, modified: &'a str) -> Vec<Diff<'a, str>> {
         let solution = myers::diff(original.as_bytes(), modified.as_bytes());
 
@@ -229,7 +227,7 @@ impl Default for DiffOptions {
 }
 
 // TODO determine if this should be exposed in the public API
-#[allow(dead_code)]
+#[cfg_attr(not(test), expect(dead_code))]
 fn diff<'a>(original: &'a str, modified: &'a str) -> Vec<Diff<'a, str>> {
     DiffOptions::default().diff(original, modified)
 }
diff --git a/src/diff/tests.rs b/src/diff/tests.rs
index 6255ff2c..16a38fe5 100644
--- a/src/diff/tests.rs
+++ b/src/diff/tests.rs
@@ -1,10 +1,10 @@
 use super::*;
+use crate::PatchFormatter;
 use crate::apply::apply;
 use crate::diff::Diff;
 use crate::diff::DiffRange;
 use crate::patch::Patch;
 use crate::range::Range;
-use crate::PatchFormatter;
 use alloc::format;
 use alloc::string::ToString;
 use alloc::vec;
@@ -59,7 +59,7 @@ macro_rules! assert_diff_range {
             expected, $solution,
         );
     };
-    ([$($kind:ident($text:literal)),* $(,)?], $solution:ident, $msg:expr $(,)?) => {
+    ([$($kind:ident($text:literal)),* $(,)?], $solution:ident, $msg:expr_2021 $(,)?) => {
         let expected = &[$(Diff::$kind($text)),*];
         assert!(
             same_diffs(expected, &$solution),
@@ -91,7 +91,7 @@ macro_rules! assert_diff {
             expected, $solution,
         );
     };
-    ([$($kind:ident($text:literal)),* $(,)?], $solution:ident, $msg:expr $(,)?) => {
+    ([$($kind:ident($text:literal)),* $(,)?], $solution:ident, $msg:expr_2021 $(,)?) => {
         let expected: &[_] = &[$(Diff::$kind($text)),*];
         assert_eq!(
             expected,
@@ -328,7 +328,7 @@ fn test_compact() {
 }
 
 macro_rules! assert_patch {
-    ($diff_options:expr, $old:ident, $new:ident, $expected:ident $(,)?) => {
+    ($diff_options:expr_2021, $old:ident, $new:ident, $expected:ident $(,)?) => {
         let patch = $diff_options.create_patch($old, $new);
         let bpatch = $diff_options.create_patch_bytes($old.as_bytes(), $new.as_bytes());
         let patch_str = patch.to_string();
diff --git a/src/lib.rs b/src/lib.rs
index 6504856c..162484a6 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -22,7 +22,7 @@
 //! This crate is `no_std` by default.
 //! Enable [Cargo features] as needed:
 //!
-//! - `std` for writer-based formatting and `std::error::Error` impls
+//! - `std` for std::io::Write-based formatting impls
 //! - `color` for ANSI-colored patch formatting
 //! - `binary` for applying parsed git binary patches
 //!
@@ -112,8 +112,8 @@
 //! image.
 //!
 //! ```
-//! use diffy::apply;
 //! use diffy::Patch;
+//! use diffy::apply;
 //!
 //! let s = "\
 //! --- a/skybreaker-ideals
@@ -323,16 +323,16 @@ pub mod patch_set;
 mod range;
 mod utils;
 
+pub use apply::ApplyError;
 pub use apply::apply;
 pub use apply::apply_bytes;
-pub use apply::ApplyError;
+pub use diff::DiffOptions;
 pub use diff::create_patch;
 pub use diff::create_patch_bytes;
-pub use diff::DiffOptions;
-pub use merge::merge;
-pub use merge::merge_bytes;
 pub use merge::ConflictStyle;
 pub use merge::MergeOptions;
+pub use merge::merge;
+pub use merge::merge_bytes;
 pub use patch::Hunk;
 pub use patch::HunkRange;
 pub use patch::Line;
diff --git a/src/merge/mod.rs b/src/merge/mod.rs
index 15744df4..21f9197a 100644
--- a/src/merge/mod.rs
+++ b/src/merge/mod.rs
@@ -424,10 +424,10 @@ fn merge_solutions<'ancestor, 'ours, 'theirs, T: ?Sized + SliceLike>(
 
         solution.push(merge_range);
 
-        if ours.map_or(true, |range| range.is_empty()) {
+        if ours.is_none_or(|range| range.is_empty()) {
             ours = our_solution.next();
         }
-        if theirs.map_or(true, |range| range.is_empty()) {
+        if theirs.is_none_or(|range| range.is_empty()) {
             theirs = their_solution.next();
         }
     }
@@ -524,7 +524,6 @@ fn create_merge_range<'ancestor, 'ours, 'theirs, T: ?Sized + SliceLike>(
     }
 }
 
-#[allow(clippy::needless_lifetimes)]
 fn cleanup_conflicts<'ancestor, 'ours, 'theirs, T: ?Sized + SliceLike + PartialEq>(
     solution: &mut [MergeRange<'ancestor, 'ours, 'theirs, T>],
 ) {
diff --git a/src/merge/tests.rs b/src/merge/tests.rs
index ff408605..99188df2 100644
--- a/src/merge/tests.rs
+++ b/src/merge/tests.rs
@@ -1,14 +1,14 @@
 use super::*;
 
 macro_rules! assert_merge {
-    ($original:ident, $ours:ident, $theirs:ident, $kind:ident($expected:expr), $msg:literal $(,)?) => {
+    ($original:ident, $ours:ident, $theirs:ident, $kind:ident($expected:expr_2021), $msg:literal $(,)?) => {
         let solution = merge($original, $ours, $theirs);
 
         macro_rules! result {
-            (Ok, $s:expr) => {
+            (Ok, $s:expr_2021) => {
                 Result::<&str, &str>::Ok($s)
             };
-            (Err, $s:expr) => {
+            (Err, $s:expr_2021) => {
                 Result::<&str, &str>::Err($s)
             };
         }
@@ -23,10 +23,10 @@ macro_rules! assert_merge {
             merge_bytes($original.as_bytes(), $ours.as_bytes(), $theirs.as_bytes());
 
         macro_rules! result_bytes {
-            (Ok, $s:expr) => {
+            (Ok, $s:expr_2021) => {
                 Result::<&[u8], &[u8]>::Ok($s.as_bytes())
             };
-            (Err, $s:expr) => {
+            (Err, $s:expr_2021) => {
                 Result::<&[u8], &[u8]>::Err($s.as_bytes())
             };
         }
diff --git a/src/patch/error.rs b/src/patch/error.rs
index be3ffa9e..33767ec5 100644
--- a/src/patch/error.rs
+++ b/src/patch/error.rs
@@ -36,9 +36,7 @@ impl fmt::Display for ParsePatchError {
     }
 }
 
-#[cfg(feature = "std")]
-#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
-impl std::error::Error for ParsePatchError {}
+impl core::error::Error for ParsePatchError {}
 
 impl From<ParsePatchErrorKind> for ParsePatchError {
     fn from(kind: ParsePatchErrorKind) -> Self {
diff --git a/src/patch/format.rs b/src/patch/format.rs
index 4cb8e43d..8f172d32 100644
--- a/src/patch/format.rs
+++ b/src/patch/format.rs
@@ -6,20 +6,20 @@ use core::fmt::Result;
 #[cfg(feature = "std")]
 use std::io;
 
-#[cfg(feature = "color")]
-use super::style;
 use super::Hunk;
 use super::Line;
-use super::Patch;
 use super::NO_NEWLINE_AT_EOF;
+use super::Patch;
+#[cfg(feature = "color")]
+use super::style;
 
 /// Formats patches for display or writing into byte streams.
 ///
 /// # Examples
 ///
 /// ```
-/// use diffy::create_patch;
 /// use diffy::PatchFormatter;
+/// use diffy::create_patch;
 ///
 /// let patch = create_patch("alpha\nbeta\n", "ALPHA\nbeta\n");
 /// let formatter = PatchFormatter::new().missing_newline_message(false);
diff --git a/src/patch/mod.rs b/src/patch/mod.rs
index c17634a8..f75f6e97 100644
--- a/src/patch/mod.rs
+++ b/src/patch/mod.rs
@@ -146,7 +146,7 @@ impl<'a> Patch<'a, str> {
     ///
     /// let patch = Patch::from_str(s).unwrap();
     /// ```
-    #[allow(clippy::should_implement_trait)]
+    #[expect(clippy::should_implement_trait)]
     pub fn from_str(s: &'a str) -> Result<Patch<'a, str>, ParsePatchError> {
         parse::parse(s)
     }
diff --git a/src/patch/parse.rs b/src/patch/parse.rs
index c730da07..849e9125 100644
--- a/src/patch/parse.rs
+++ b/src/patch/parse.rs
@@ -1,15 +1,15 @@
 //! Parse a Patch
 
-use super::error::ParsePatchError;
-use super::error::ParsePatchErrorKind;
 use super::Hunk;
 use super::HunkRange;
 use super::Line;
 use super::NO_NEWLINE_AT_EOF;
+use super::error::ParsePatchError;
+use super::error::ParsePatchErrorKind;
 use crate::patch::Patch;
-use crate::utils::escaped_filename;
 use crate::utils::LineIter;
 use crate::utils::Text;
+use crate::utils::escaped_filename;
 use alloc::borrow::Cow;
 use alloc::vec::Vec;
 
@@ -38,7 +38,6 @@ impl ParseOpts {
     ///
     /// Useful when the caller has already positioned the input
     /// at the start of the patch content.
-    #[allow(dead_code)] // will be used by patch_set parser
     pub(crate) fn no_skip_preamble(mut self) -> Self {
         self.skip_preamble = false;
         self
@@ -145,7 +144,7 @@ pub(crate) fn parse_one<T: Text + ?Sized>(
     (Ok(Patch::new(header.0, header.1, hunks)), parser.offset())
 }
 
-#[allow(clippy::type_complexity)]
+#[expect(clippy::type_complexity)]
 fn patch_header<'a, T: Text + ?Sized>(
     parser: &mut Parser<'a, T>,
     opts: &ParseOpts,
diff --git a/src/patch/tests.rs b/src/patch/tests.rs
index c61c37c6..6fe864d0 100644
--- a/src/patch/tests.rs
+++ b/src/patch/tests.rs
@@ -644,8 +644,8 @@ fn non_utf8_escaped_filename_returns_error_on_str_parse() {
 mod error_display {
     use alloc::string::ToString;
 
-    use crate::patch::error::ParsePatchErrorKind;
     use crate::Patch;
+    use crate::patch::error::ParsePatchErrorKind;
     use snapbox::assert_data_eq;
     use snapbox::str;
 
diff --git a/src/patch_set/error.rs b/src/patch_set/error.rs
index 6a169445..798c3d7c 100644
--- a/src/patch_set/error.rs
+++ b/src/patch_set/error.rs
@@ -43,9 +43,7 @@ impl fmt::Display for PatchSetParseError {
     }
 }
 
-#[cfg(feature = "std")]
-#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
-impl std::error::Error for PatchSetParseError {}
+impl core::error::Error for PatchSetParseError {}
 
 impl From<PatchSetParseErrorKind> for PatchSetParseError {
     fn from(kind: PatchSetParseErrorKind) -> Self {
diff --git a/src/patch_set/mod.rs b/src/patch_set/mod.rs
index 2b341c29..15f94d5a 100644
--- a/src/patch_set/mod.rs
+++ b/src/patch_set/mod.rs
@@ -12,9 +12,9 @@ use alloc::borrow::Cow;
 use alloc::borrow::ToOwned;
 use core::fmt;
 
+use crate::Patch;
 use crate::binary::BinaryPatch;
 use crate::utils::Text;
-use crate::Patch;
 
 pub use error::PatchSetParseError;
 use error::PatchSetParseErrorKind;
diff --git a/src/patch_set/parse.rs b/src/patch_set/parse.rs
index 14409556..8facc78c 100644
--- a/src/patch_set/parse.rs
+++ b/src/patch_set/parse.rs
@@ -1,18 +1,18 @@
 //! Parse multiple file patches from a unified diff.
 
-use super::error::PatchSetParseErrorKind;
 use super::FileMode;
 use super::FileOperation;
 use super::FilePatch;
 use super::Format;
 use super::ParseOptions;
 use super::PatchSetParseError;
-use crate::binary::parse_binary_patch;
+use super::error::PatchSetParseErrorKind;
+use crate::Patch;
 use crate::binary::BinaryPatch;
+use crate::binary::parse_binary_patch;
 use crate::patch::parse::parse_one;
-use crate::utils::escaped_filename;
 use crate::utils::Text;
-use crate::Patch;
+use crate::utils::escaped_filename;
 
 use alloc::borrow::Cow;
 use alloc::string::String;
@@ -610,7 +610,7 @@ fn parse_unquoted_diff_git_path<'a, T: Text + ?Sized>(
     let mut best_match = None;
     let mut longest_path_len = 0;
 
-    for (i, _) in bytes.iter().enumerate().filter(|(_, &b)| b == b' ') {
+    for (i, _) in bytes.iter().enumerate().filter(|&(_, &b)| b == b' ') {
         let (left, right_with_space) = line.split_at(i);
         // skip the space
         let (_, right) = right_with_space.split_at(1);
diff --git a/src/patch_set/tests.rs b/src/patch_set/tests.rs
index 0ab01fea..8d35809c 100644
--- a/src/patch_set/tests.rs
+++ b/src/patch_set/tests.rs
@@ -4,10 +4,10 @@ use alloc::borrow::ToOwned;
 use alloc::string::ToString;
 use alloc::vec::Vec;
 
-use super::error::PatchSetParseErrorKind;
 use super::FileOperation;
 use super::ParseOptions;
 use super::PatchSet;
+use super::error::PatchSetParseErrorKind;
 
 mod file_operation {
     use super::*;
diff --git a/src/range.rs b/src/range.rs
index 5e454c90..cb9c22c5 100644
--- a/src/range.rs
+++ b/src/range.rs
@@ -35,7 +35,6 @@ impl<'a, T: ?Sized> Range<'a, T> {
         self.offset
     }
 
-    #[allow(dead_code)]
     pub fn range(&self) -> ops::Range<usize> {
         self.offset..self.offset + self.len
     }
@@ -98,7 +97,6 @@ where
         Range { inner, offset, len }
     }
 
-    #[allow(dead_code)]
     pub fn empty() -> Range<'a, T> {
         Range {
             inner: T::empty(),
@@ -119,17 +117,17 @@ where
         self.as_slice().common_suffix_len(other.as_slice())
     }
 
-    #[allow(dead_code)]
+    #[cfg_attr(not(test), expect(dead_code))]
     pub fn common_overlap_len(&self, other: Range<'_, T>) -> usize {
         self.as_slice().common_overlap_len(other.as_slice())
     }
 
-    #[allow(dead_code)]
+    #[expect(dead_code)]
     pub fn starts_with(&self, prefix: Range<'_, T>) -> bool {
         self.as_slice().starts_with(prefix.as_slice())
     }
 
-    #[allow(dead_code)]
+    #[expect(dead_code)]
     pub fn ends_with(&self, suffix: Range<'_, T>) -> bool {
         self.as_slice().ends_with(suffix.as_slice())
     }
diff --git a/src/utils.rs b/src/utils.rs
index bfbd16e0..d94d56b7 100644
--- a/src/utils.rs
+++ b/src/utils.rs
@@ -5,11 +5,11 @@ use alloc::borrow::ToOwned;
 use alloc::string::String;
 use alloc::vec::Vec;
 use core::hash::Hash;
-use hashbrown::hash_map::Entry;
 use hashbrown::HashMap;
+use hashbrown::hash_map::Entry;
 
-use crate::patch::error::ParsePatchErrorKind;
 use crate::ParsePatchError;
+use crate::patch::error::ParsePatchErrorKind;
 
 /// Returns `true` if a byte must be quoted in a diff filename.
 ///
@@ -140,7 +140,6 @@ pub trait Text: Eq + Hash + ToOwned {
     fn is_empty(&self) -> bool;
     fn len(&self) -> usize;
     fn starts_with(&self, prefix: &str) -> bool;
-    #[allow(unused)]
     fn ends_with(&self, suffix: &str) -> bool;
     fn strip_prefix(&self, prefix: &str) -> Option<&Self>;
     fn strip_suffix(&self, suffix: &str) -> Option<&Self>;
@@ -149,7 +148,6 @@ pub trait Text: Eq + Hash + ToOwned {
     fn split_at(&self, mid: usize) -> (&Self, &Self);
     fn as_str(&self) -> Option<&str>;
     fn as_bytes(&self) -> &[u8];
-    #[allow(unused)]
     fn lines(&self) -> LineIter<'_, Self>;
 
     /// Converts raw bytes into `Self::Owned`.