diff --git a/book/src/user/wasm-port.md b/book/src/user/wasm-port.md
index 97ad346b..97c56917 100644
--- a/book/src/user/wasm-port.md
+++ b/book/src/user/wasm-port.md
@@ -12,7 +12,7 @@ In the case of Zordle, this code is contained in [wasm.rs](https://github.com/na
 
 ### Prover
 
-```rust
+```rust,ignore
 #[wasm_bindgen]
 pub async fn prove_play(final_word: String, words_js: JsValue, params_ser: JsValue) -> JsValue {
   // Steps:
@@ -34,7 +34,7 @@ The output is a `Vec<u8>` converted to a `JSValue` using Serde. This is later pa
 
 ### Verifier
 
-```rust
+```rust,ignore
 #[wasm_bindgen]
 pub fn verify_play(final_word: String, proof_js: JsValue, diffs_u64_js: JsValue, params_ser: JsValue) -> bool {
   // Steps:
@@ -51,7 +51,7 @@ Similar to the prover, we take in input and output a boolean true/false indicati
 
 Additionally, both the prover and verifier functions input `params_ser`, a serialised form of the public parameters of the polynomial commitment scheme. These are passed in as input (instead of being regenerated in prove/verify functions) as a performance optimisation since these are constant based only on the circuit's value of `K`. We can store these seperately on a static web server and pass them in as input to the WASM. To generate the binary serialised form of these (seperately outside the WASM functions), you can run something like:
 
-```rust
+```rust,ignore
 fn write_params(K: u32) {
     let mut params_file = File::create("params.bin").unwrap();
     let params: Params<EqAffine> = Params::new(K);
@@ -124,4 +124,4 @@ Often, you'll run into issues with your Rust code and see that the WASM executio
 
 ## Credits
 
-This guide was written by [Nalin](https://twitter.com/nibnalin). Thanks additionally to [Uma](https://twitter.com/pumatheuma) and [Blaine](https://twitter.com/BlaineBublitz) for significant work on figuring out these steps. Feel free to reach out to me if you have trouble with any of these steps.
\ No newline at end of file
+This guide was written by [Nalin](https://twitter.com/nibnalin). Thanks additionally to [Uma](https://twitter.com/pumatheuma) and [Blaine](https://twitter.com/BlaineBublitz) for significant work on figuring out these steps. Feel free to reach out to me if you have trouble with any of these steps.
diff --git a/halo2_gadgets/benches/poseidon.rs b/halo2_gadgets/benches/poseidon.rs
index a25b7c21..9b80b560 100644
--- a/halo2_gadgets/benches/poseidon.rs
+++ b/halo2_gadgets/benches/poseidon.rs
@@ -131,7 +131,7 @@ impl Spec<Fp, 3, 2> for MySpec<3, 2> {
     }
 
     fn sbox(val: Fp) -> Fp {
-        val.pow_vartime(&[5])
+        val.pow_vartime([5])
     }
 
     fn secure_mds() -> usize {
@@ -153,7 +153,7 @@ impl Spec<Fp, 9, 8> for MySpec<9, 8> {
     }
 
     fn sbox(val: Fp) -> Fp {
-        val.pow_vartime(&[5])
+        val.pow_vartime([5])
     }
 
     fn secure_mds() -> usize {
@@ -175,7 +175,7 @@ impl Spec<Fp, 12, 11> for MySpec<12, 11> {
     }
 
     fn sbox(val: Fp) -> Fp {
-        val.pow_vartime(&[5])
+        val.pow_vartime([5])
     }
 
     fn secure_mds() -> usize {
diff --git a/halo2_gadgets/benches/sha256.rs b/halo2_gadgets/benches/sha256.rs
index baf9c977..e289d390 100644
--- a/halo2_gadgets/benches/sha256.rs
+++ b/halo2_gadgets/benches/sha256.rs
@@ -79,18 +79,18 @@ fn bench(name: &str, k: u32, c: &mut Criterion) {
 
     // Initialize the polynomial commitment parameters
     let params_path = Path::new("./benches/sha256_assets/sha256_params");
-    if File::open(&params_path).is_err() {
+    if File::open(params_path).is_err() {
         let params: Params<EqAffine> = Params::new(k);
         let mut buf = Vec::new();
 
         params.write(&mut buf).expect("Failed to write params");
-        let mut file = File::create(&params_path).expect("Failed to create sha256_params");
+        let mut file = File::create(params_path).expect("Failed to create sha256_params");
 
         file.write_all(&buf[..])
             .expect("Failed to write params to file");
     }
 
-    let params_fs = File::open(&params_path).expect("couldn't load sha256_params");
+    let params_fs = File::open(params_path).expect("couldn't load sha256_params");
     let params: Params<EqAffine> =
         Params::read::<_>(&mut BufReader::new(params_fs)).expect("Failed to read params");
 
@@ -117,16 +117,16 @@ fn bench(name: &str, k: u32, c: &mut Criterion) {
 
     // Create a proof
     let proof_path = Path::new("./benches/sha256_assets/sha256_proof");
-    if File::open(&proof_path).is_err() {
+    if File::open(proof_path).is_err() {
         let mut transcript = Blake2bWrite::<_, _, Challenge255<_>>::init(vec![]);
         create_proof(&params, &pk, &[circuit], &[], OsRng, &mut transcript)
             .expect("proof generation should not fail");
         let proof: Vec<u8> = transcript.finalize();
-        let mut file = File::create(&proof_path).expect("Failed to create sha256_proof");
+        let mut file = File::create(proof_path).expect("Failed to create sha256_proof");
         file.write_all(&proof[..]).expect("Failed to write proof");
     }
 
-    let mut proof_fs = File::open(&proof_path).expect("couldn't load sha256_proof");
+    let mut proof_fs = File::open(proof_path).expect("couldn't load sha256_proof");
     let mut proof = Vec::<u8>::new();
     proof_fs
         .read_to_end(&mut proof)
diff --git a/halo2_gadgets/src/ecc.rs b/halo2_gadgets/src/ecc.rs
index 3cd2d87a..38fab0a4 100644
--- a/halo2_gadgets/src/ecc.rs
+++ b/halo2_gadgets/src/ecc.rs
@@ -437,14 +437,14 @@ impl<C: CurveAffine, EccChip: EccInstructions<C> + Clone + Debug + Eq> Point<C,
 /// The affine short Weierstrass x-coordinate of a point on a specific elliptic curve.
 #[derive(Debug)]
 pub struct X<C: CurveAffine, EccChip: EccInstructions<C>> {
-    chip: EccChip,
     inner: EccChip::X,
 }
 
 impl<C: CurveAffine, EccChip: EccInstructions<C>> X<C, EccChip> {
     /// Wraps the given x-coordinate (obtained directly from an instruction) in a gadget.
     pub fn from_inner(chip: EccChip, inner: EccChip::X) -> Self {
-        X { chip, inner }
+        let _ = chip; // unused
+        X { inner }
     }
 
     /// Returns the inner x-coordinate.
diff --git a/halo2_gadgets/src/ecc/chip/mul_fixed.rs b/halo2_gadgets/src/ecc/chip/mul_fixed.rs
index df456853..c1aa5c08 100644
--- a/halo2_gadgets/src/ecc/chip/mul_fixed.rs
+++ b/halo2_gadgets/src/ecc/chip/mul_fixed.rs
@@ -493,7 +493,7 @@ impl ScalarFixed {
                         .by_vals()
                         .take(FIXED_BASE_WINDOW_SIZE)
                         .rev()
-                        .fold(0, |acc, b| 2 * acc + if b { 1 } else { 0 })
+                        .fold(0, |acc, b| 2 * acc + usize::from(b))
                 })
             })
             .collect::<Vec<_>>()
diff --git a/halo2_gadgets/src/poseidon/pow5.rs b/halo2_gadgets/src/poseidon/pow5.rs
index 9c98eb75..6c125ea6 100644
--- a/halo2_gadgets/src/poseidon/pow5.rs
+++ b/halo2_gadgets/src/poseidon/pow5.rs
@@ -33,7 +33,6 @@ pub struct Pow5Config<F: Field, const WIDTH: usize, const RATE: usize> {
     alpha: [u64; 4],
     round_constants: Vec<[F; WIDTH]>,
     m_reg: Mds<F, WIDTH>,
-    m_inv: Mds<F, WIDTH>,
 }
 
 /// A Poseidon chip using an $x^5$ S-Box.
@@ -200,7 +199,6 @@ impl<F: Field, const WIDTH: usize, const RATE: usize> Pow5Chip<F, WIDTH, RATE> {
             alpha,
             round_constants,
             m_reg,
-            m_inv,
         }
     }
 
diff --git a/halo2_gadgets/src/poseidon/primitives/p128pow5t3.rs b/halo2_gadgets/src/poseidon/primitives/p128pow5t3.rs
index dffa30bc..fe98517e 100644
--- a/halo2_gadgets/src/poseidon/primitives/p128pow5t3.rs
+++ b/halo2_gadgets/src/poseidon/primitives/p128pow5t3.rs
@@ -22,7 +22,7 @@ impl Spec<Fp, 3, 2> for P128Pow5T3 {
     }
 
     fn sbox(val: Fp) -> Fp {
-        val.pow_vartime(&[5])
+        val.pow_vartime([5])
     }
 
     fn secure_mds() -> usize {
@@ -48,7 +48,7 @@ impl Spec<Fq, 3, 2> for P128Pow5T3 {
     }
 
     fn sbox(val: Fq) -> Fq {
-        val.pow_vartime(&[5])
+        val.pow_vartime([5])
     }
 
     fn secure_mds() -> usize {
@@ -101,7 +101,7 @@ mod tests {
         }
 
         fn sbox(val: F) -> F {
-            val.pow_vartime(&[5])
+            val.pow_vartime([5])
         }
 
         fn secure_mds() -> usize {
diff --git a/halo2_gadgets/src/sha256/table16/compression/compression_util.rs b/halo2_gadgets/src/sha256/table16/compression/compression_util.rs
index cf4c366e..75f6e0b5 100644
--- a/halo2_gadgets/src/sha256/table16/compression/compression_util.rs
+++ b/halo2_gadgets/src/sha256/table16/compression/compression_util.rs
@@ -111,7 +111,7 @@ pub fn get_round_row(round_idx: RoundIdx) -> usize {
         RoundIdx::Init => 0,
         RoundIdx::Main(MainRoundIdx(idx)) => {
             assert!(idx < 64);
-            (idx as usize) * SUBREGION_MAIN_WORD
+            idx * SUBREGION_MAIN_WORD
         }
     }
 }
@@ -783,7 +783,7 @@ impl CompressionConfig {
                 || "h_prime_carry",
                 a_9,
                 row + 1,
-                || h_prime_carry.map(|value| pallas::Base::from(value as u64)),
+                || h_prime_carry.map(pallas::Base::from),
             )?;
 
             let h_prime: Value<[bool; 32]> = h_prime.map(|w| i2lebsp(w.into()));
diff --git a/halo2_gadgets/src/sha256/table16/message_schedule/schedule_util.rs b/halo2_gadgets/src/sha256/table16/message_schedule/schedule_util.rs
index 93f16430..e1e9ca4a 100644
--- a/halo2_gadgets/src/sha256/table16/message_schedule/schedule_util.rs
+++ b/halo2_gadgets/src/sha256/table16/message_schedule/schedule_util.rs
@@ -40,20 +40,17 @@ pub fn get_word_row(word_idx: usize) -> usize {
     if word_idx == 0 {
         0
     } else if (1..=13).contains(&word_idx) {
-        SUBREGION_0_ROWS + SUBREGION_1_WORD * (word_idx - 1) as usize
+        SUBREGION_0_ROWS + SUBREGION_1_WORD * (word_idx - 1)
     } else if (14..=48).contains(&word_idx) {
         SUBREGION_0_ROWS + SUBREGION_1_ROWS + SUBREGION_2_WORD * (word_idx - 14) + 1
     } else if (49..=61).contains(&word_idx) {
-        SUBREGION_0_ROWS
-            + SUBREGION_1_ROWS
-            + SUBREGION_2_ROWS
-            + SUBREGION_3_WORD * (word_idx - 49) as usize
+        SUBREGION_0_ROWS + SUBREGION_1_ROWS + SUBREGION_2_ROWS + SUBREGION_3_WORD * (word_idx - 49)
     } else {
         SUBREGION_0_ROWS
             + SUBREGION_1_ROWS
             + SUBREGION_2_ROWS
             + SUBREGION_3_ROWS
-            + DECOMPOSE_0_ROWS * (word_idx - 62) as usize
+            + DECOMPOSE_0_ROWS * (word_idx - 62)
     }
 }
 
diff --git a/halo2_gadgets/src/sha256/table16/message_schedule/subregion1.rs b/halo2_gadgets/src/sha256/table16/message_schedule/subregion1.rs
index e30c32ee..8c4e003a 100644
--- a/halo2_gadgets/src/sha256/table16/message_schedule/subregion1.rs
+++ b/halo2_gadgets/src/sha256/table16/message_schedule/subregion1.rs
@@ -14,8 +14,8 @@ pub struct Subregion1Word {
     index: usize,
     a: AssignedBits<3>,
     b: AssignedBits<4>,
-    c: AssignedBits<11>,
-    d: AssignedBits<14>,
+    _c: AssignedBits<11>,
+    _d: AssignedBits<14>,
     spread_c: AssignedBits<22>,
     spread_d: AssignedBits<28>,
 }
@@ -142,8 +142,8 @@ impl MessageScheduleConfig {
             index,
             a,
             b,
-            c: spread_c.dense,
-            d: spread_d.dense,
+            _c: spread_c.dense,
+            _d: spread_d.dense,
             spread_c: spread_c.spread,
             spread_d: spread_d.spread,
         })
diff --git a/halo2_gadgets/src/sha256/table16/message_schedule/subregion2.rs b/halo2_gadgets/src/sha256/table16/message_schedule/subregion2.rs
index e5e25fae..0480d044 100644
--- a/halo2_gadgets/src/sha256/table16/message_schedule/subregion2.rs
+++ b/halo2_gadgets/src/sha256/table16/message_schedule/subregion2.rs
@@ -15,10 +15,10 @@ pub struct Subregion2Word {
     a: AssignedBits<3>,
     b: AssignedBits<4>,
     c: AssignedBits<3>,
-    d: AssignedBits<7>,
+    _d: AssignedBits<7>,
     e: AssignedBits<1>,
     f: AssignedBits<1>,
-    g: AssignedBits<13>,
+    _g: AssignedBits<13>,
     spread_d: AssignedBits<14>,
     spread_g: AssignedBits<26>,
 }
@@ -261,7 +261,7 @@ impl MessageScheduleConfig {
                 || format!("carry_{}", new_word_idx),
                 a_9,
                 get_word_row(new_word_idx - 16) + 1,
-                || carry.map(|carry| pallas::Base::from(carry as u64)),
+                || carry.map(pallas::Base::from),
             )?;
             let (word, halves) = self.assign_word_and_halves(region, word, new_word_idx)?;
             w.push(MessageWord(word));
@@ -342,10 +342,10 @@ impl MessageScheduleConfig {
             a,
             b: spread_b.dense,
             c,
-            d: spread_d.dense,
+            _d: spread_d.dense,
             e,
             f,
-            g: spread_g.dense,
+            _g: spread_g.dense,
             spread_d: spread_d.spread,
             spread_g: spread_g.spread,
         })
diff --git a/halo2_gadgets/src/sha256/table16/message_schedule/subregion3.rs b/halo2_gadgets/src/sha256/table16/message_schedule/subregion3.rs
index 6ce3d290..ddb36ebf 100644
--- a/halo2_gadgets/src/sha256/table16/message_schedule/subregion3.rs
+++ b/halo2_gadgets/src/sha256/table16/message_schedule/subregion3.rs
@@ -177,7 +177,7 @@ impl MessageScheduleConfig {
                 || format!("carry_{}", new_word_idx),
                 a_9,
                 get_word_row(new_word_idx - 16) + 1,
-                || carry.map(|carry| pallas::Base::from(carry as u64)),
+                || carry.map(pallas::Base::from),
             )?;
             let (word, halves) = self.assign_word_and_halves(region, word, new_word_idx)?;
             w.push(MessageWord(word));
diff --git a/halo2_gadgets/src/sha256/table16/spread_table.rs b/halo2_gadgets/src/sha256/table16/spread_table.rs
index 891799eb..7342e6af 100644
--- a/halo2_gadgets/src/sha256/table16/spread_table.rs
+++ b/halo2_gadgets/src/sha256/table16/spread_table.rs
@@ -69,7 +69,7 @@ impl<const DENSE: usize, const SPREAD: usize> SpreadWord<DENSE, SPREAD> {
 /// A variable stored in advice columns corresponding to a row of [`SpreadTableConfig`].
 #[derive(Clone, Debug)]
 pub(super) struct SpreadVar<const DENSE: usize, const SPREAD: usize> {
-    pub tag: Value<u8>,
+    pub _tag: Value<u8>,
     pub dense: AssignedBits<DENSE>,
     pub spread: AssignedBits<SPREAD>,
 }
@@ -98,7 +98,11 @@ impl<const DENSE: usize, const SPREAD: usize> SpreadVar<DENSE, SPREAD> {
         let spread =
             AssignedBits::<SPREAD>::assign_bits(region, || "spread", cols.spread, row, spread_val)?;
 
-        Ok(SpreadVar { tag, dense, spread })
+        Ok(SpreadVar {
+            _tag: tag,
+            dense,
+            spread,
+        })
     }
 
     pub(super) fn without_lookup(
@@ -129,7 +133,11 @@ impl<const DENSE: usize, const SPREAD: usize> SpreadVar<DENSE, SPREAD> {
             spread_val,
         )?;
 
-        Ok(SpreadVar { tag, dense, spread })
+        Ok(SpreadVar {
+            _tag: tag,
+            dense,
+            spread,
+        })
     }
 }
 
diff --git a/halo2_gadgets/src/sha256/table16/util.rs b/halo2_gadgets/src/sha256/table16/util.rs
index 6a790d37..628f0374 100644
--- a/halo2_gadgets/src/sha256/table16/util.rs
+++ b/halo2_gadgets/src/sha256/table16/util.rs
@@ -110,7 +110,7 @@ pub fn sum_with_carry(words: Vec<(Value<u16>, Value<u16>)>) -> (Value<u32>, Valu
         sum_lo.zip(sum_hi).map(|(lo, hi)| lo + (1 << 16) * hi)
     };
 
-    let carry = sum.map(|sum| (sum >> 32) as u64);
+    let carry = sum.map(|sum| sum >> 32);
     let sum = sum.map(|sum| sum as u32);
 
     (sum, carry)
diff --git a/halo2_gadgets/src/sinsemilla.rs b/halo2_gadgets/src/sinsemilla.rs
index bb662d3f..11e4b24a 100644
--- a/halo2_gadgets/src/sinsemilla.rs
+++ b/halo2_gadgets/src/sinsemilla.rs
@@ -166,7 +166,6 @@ pub struct MessagePiece<C: CurveAffine, SinsemillaChip, const K: usize, const MA
 where
     SinsemillaChip: SinsemillaInstructions<C, K, MAX_WORDS> + Clone + Debug + Eq,
 {
-    chip: SinsemillaChip,
     inner: SinsemillaChip::MessagePiece,
 }
 
@@ -199,7 +198,7 @@ where
         // Each message piece must have at most `floor(C::Base::CAPACITY / K)` words.
         // This ensures that the all-ones bitstring is canonical in the field.
         let piece_max_num_words = C::Base::CAPACITY as usize / K;
-        assert!(num_words <= piece_max_num_words as usize);
+        assert!(num_words <= piece_max_num_words);
 
         // Closure to parse a bitstring (little-endian) into a base field element.
         let to_base_field = |bits: &[Value<bool>]| -> Value<C::Base> {
@@ -227,7 +226,7 @@ where
         num_words: usize,
     ) -> Result<Self, Error> {
         let inner = chip.witness_message_piece(layouter, field_elem, num_words)?;
-        Ok(Self { chip, inner })
+        Ok(Self { inner })
     }
 
     /// Constructs a `MessagePiece` by concatenating a sequence of [`RangeConstrained`]
diff --git a/halo2_proofs/CHANGELOG.md b/halo2_proofs/CHANGELOG.md
index 12bdcee8..7ae956b4 100644
--- a/halo2_proofs/CHANGELOG.md
+++ b/halo2_proofs/CHANGELOG.md
@@ -6,6 +6,15 @@ and this project adheres to Rust's notion of
 [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
+- The following structs now derive the `Eq` trait:
+  - `halo2_proofs::dev`:
+    - `failure::FailureLocation`
+    - `failure::VerifyFailure`
+    - `metadata::Gate`
+    - `metadata::Constraint`
+    - `metadata::Region`
+  - `halo2_proofs::poly::Rotation`
+
 ### Added
 - `halo2_proofs::arithmetic::FftGroup`
 - `halo2_proofs::circuit::layouter`:
diff --git a/halo2_proofs/src/arithmetic.rs b/halo2_proofs/src/arithmetic.rs
index 6c2b2af5..2bc2ce17 100644
--- a/halo2_proofs/src/arithmetic.rs
+++ b/halo2_proofs/src/arithmetic.rs
@@ -195,7 +195,7 @@ pub fn best_fft<Scalar: Field, G: FftGroup<Scalar>>(a: &mut [G], omega: Scalar,
 
     let threads = multicore::current_num_threads();
     let log_threads = log2_floor(threads);
-    let n = a.len() as usize;
+    let n = a.len();
     assert_eq!(n, 1 << log_n);
 
     for k in 0..n {
@@ -206,7 +206,7 @@ pub fn best_fft<Scalar: Field, G: FftGroup<Scalar>>(a: &mut [G], omega: Scalar,
     }
 
     // precompute twiddle factors
-    let twiddles: Vec<_> = (0..(n / 2) as usize)
+    let twiddles: Vec<_> = (0..(n / 2))
         .scan(Scalar::one(), |w, _| {
             let tw = *w;
             *w *= &omega;
@@ -216,7 +216,7 @@ pub fn best_fft<Scalar: Field, G: FftGroup<Scalar>>(a: &mut [G], omega: Scalar,
 
     if log_n <= log_threads {
         let mut chunk = 2_usize;
-        let mut twiddle_chunk = (n / 2) as usize;
+        let mut twiddle_chunk = n / 2;
         for _ in 0..log_n {
             a.chunks_mut(chunk).for_each(|coeffs| {
                 let (left, right) = coeffs.split_at_mut(chunk / 2);
@@ -339,9 +339,9 @@ where
 pub fn parallelize<T: Send, F: Fn(&mut [T], usize) + Send + Sync + Clone>(v: &mut [T], f: F) {
     let n = v.len();
     let num_threads = multicore::current_num_threads();
-    let mut chunk = (n as usize) / num_threads;
+    let mut chunk = n / num_threads;
     if chunk < num_threads {
-        chunk = n as usize;
+        chunk = n;
     }
 
     multicore::scope(|scope| {
@@ -374,7 +374,7 @@ pub fn lagrange_interpolate<F: Field>(points: &[F], evals: &[F]) -> Vec<F> {
     assert_eq!(points.len(), evals.len());
     if points.len() == 1 {
         // Constant polynomial
-        return vec![evals[0]];
+        vec![evals[0]]
     } else {
         let mut denoms = Vec::with_capacity(points.len());
         for (j, x_j) in points.iter().enumerate() {
diff --git a/halo2_proofs/src/circuit/floor_planner/v1.rs b/halo2_proofs/src/circuit/floor_planner/v1.rs
index b6f18215..fe24d10e 100644
--- a/halo2_proofs/src/circuit/floor_planner/v1.rs
+++ b/halo2_proofs/src/circuit/floor_planner/v1.rs
@@ -81,8 +81,8 @@ impl FloorPlanner for V1 {
 
         // - Determine how many rows our planned circuit will require.
         let first_unassigned_row = column_allocations
-            .iter()
-            .map(|(_, a)| a.unbounded_interval_start())
+            .values()
+            .map(|a| a.unbounded_interval_start())
             .max()
             .unwrap_or(0);
 
diff --git a/halo2_proofs/src/dev/cost.rs b/halo2_proofs/src/dev/cost.rs
index ceb20acb..7f82f1b2 100644
--- a/halo2_proofs/src/dev/cost.rs
+++ b/halo2_proofs/src/dev/cost.rs
@@ -21,6 +21,7 @@ use crate::{
 };
 
 /// Measures a circuit to determine its costs, and explain what contributes to them.
+#[allow(dead_code)]
 #[derive(Debug)]
 pub struct CircuitCost<G: PrimeGroup, ConcreteCircuit: Circuit<G::Scalar>> {
     /// Power-of-2 bound on the number of rows in the circuit.
@@ -54,6 +55,7 @@ pub struct CircuitCost<G: PrimeGroup, ConcreteCircuit: Circuit<G::Scalar>> {
 }
 
 /// Region implementation used by Layout
+#[allow(dead_code)]
 #[derive(Debug)]
 pub(crate) struct LayoutRegion {
     /// The name of the region. Not required to be unique.
diff --git a/halo2_proofs/src/dev/failure.rs b/halo2_proofs/src/dev/failure.rs
index c08d1abe..c6c5aecf 100644
--- a/halo2_proofs/src/dev/failure.rs
+++ b/halo2_proofs/src/dev/failure.rs
@@ -16,7 +16,7 @@ use crate::{
 mod emitter;
 
 /// The location within the circuit at which a particular [`VerifyFailure`] occurred.
-#[derive(Debug, PartialEq)]
+#[derive(Debug, PartialEq, Eq)]
 pub enum FailureLocation {
     /// A location inside a region.
     InRegion {
@@ -100,16 +100,14 @@ impl FailureLocation {
             })
             .map(|(r_i, r)| FailureLocation::InRegion {
                 region: (r_i, r.name.clone()).into(),
-                offset: failure_row as usize - r.rows.unwrap().0 as usize,
-            })
-            .unwrap_or_else(|| FailureLocation::OutsideRegion {
-                row: failure_row as usize,
+                offset: failure_row - r.rows.unwrap().0,
             })
+            .unwrap_or_else(|| FailureLocation::OutsideRegion { row: failure_row })
     }
 }
 
 /// The reasons why a particular circuit is not satisfied.
-#[derive(Debug, PartialEq)]
+#[derive(Debug, PartialEq, Eq)]
 pub enum VerifyFailure {
     /// A cell used in an active gate was not assigned to.
     CellNotAssigned {
diff --git a/halo2_proofs/src/dev/graph/layout.rs b/halo2_proofs/src/dev/graph/layout.rs
index 6cafd087..965e0683 100644
--- a/halo2_proofs/src/dev/graph/layout.rs
+++ b/halo2_proofs/src/dev/graph/layout.rs
@@ -178,7 +178,7 @@ impl CircuitLayout {
 
         root.draw(&Rectangle::new(
             [(0, 0), (total_columns, view_bottom)],
-            &BLACK,
+            BLACK,
         ))?;
 
         let draw_region = |root: &DrawingArea<_, _>, top_left, bottom_right| {
@@ -194,7 +194,7 @@ impl CircuitLayout {
                 [top_left, bottom_right],
                 ShapeStyle::from(&GREEN.mix(0.2)).filled(),
             ))?;
-            root.draw(&Rectangle::new([top_left, bottom_right], &BLACK))?;
+            root.draw(&Rectangle::new([top_left, bottom_right], BLACK))?;
             Ok(())
         };
 
diff --git a/halo2_proofs/src/dev/metadata.rs b/halo2_proofs/src/dev/metadata.rs
index d7d2443e..9a47e3cb 100644
--- a/halo2_proofs/src/dev/metadata.rs
+++ b/halo2_proofs/src/dev/metadata.rs
@@ -83,7 +83,7 @@ impl fmt::Display for VirtualCell {
 }
 
 /// Metadata about a configured gate within a circuit.
-#[derive(Debug, PartialEq)]
+#[derive(Debug, PartialEq, Eq)]
 pub struct Gate {
     /// The index of the active gate. These indices are assigned in the order in which
     /// `ConstraintSystem::create_gate` is called during `Circuit::configure`.
@@ -106,7 +106,7 @@ impl From<(usize, &'static str)> for Gate {
 }
 
 /// Metadata about a configured constraint within a circuit.
-#[derive(Debug, PartialEq)]
+#[derive(Debug, PartialEq, Eq)]
 pub struct Constraint {
     /// The gate containing the constraint.
     pub(super) gate: Gate,
@@ -143,7 +143,7 @@ impl From<(Gate, usize, &'static str)> for Constraint {
 }
 
 /// Metadata about an assigned region within a circuit.
-#[derive(Clone, Debug, PartialEq)]
+#[derive(Clone, Debug, PartialEq, Eq)]
 pub struct Region {
     /// The index of the region. These indices are assigned in the order in which
     /// `Layouter::assign_region` is called during `Circuit::synthesize`.
diff --git a/halo2_proofs/src/plonk/assigned.rs b/halo2_proofs/src/plonk/assigned.rs
index 06b00b9d..27785ed4 100644
--- a/halo2_proofs/src/plonk/assigned.rs
+++ b/halo2_proofs/src/plonk/assigned.rs
@@ -612,7 +612,7 @@ mod proptests {
                 // Ensure that:
                 // - we have at least one value to apply unary operators to.
                 // - we can apply every binary operator pairwise sequentially.
-                cmp::max(if num_unary > 0 { 1 } else { 0 }, num_binary + 1)),
+                cmp::max(usize::from(num_unary > 0), num_binary + 1)),
             operations in arb_operators(num_unary, num_binary).prop_shuffle(),
         ) -> (Vec<Assigned<Fp>>, Vec<Operator>) {
             (values, operations)
diff --git a/halo2_proofs/src/plonk/circuit/compress_selectors.rs b/halo2_proofs/src/plonk/circuit/compress_selectors.rs
index c3a1485d..81dc27d2 100644
--- a/halo2_proofs/src/plonk/circuit/compress_selectors.rs
+++ b/halo2_proofs/src/plonk/circuit/compress_selectors.rs
@@ -70,33 +70,30 @@ where
 
     // All provided selectors of degree 0 are assumed to be either concrete
     // selectors or do not appear in a gate. Let's address these first.
-    selectors = selectors
-        .into_iter()
-        .filter(|selector| {
-            if selector.max_degree == 0 {
-                // This is a complex selector, or a selector that does not appear in any
-                // gate constraint.
-                let expression = allocate_fixed_column();
+    selectors.retain(|selector| {
+        if selector.max_degree == 0 {
+            // This is a complex selector, or a selector that does not appear in any
+            // gate constraint.
+            let expression = allocate_fixed_column();
 
-                let combination_assignment = selector
-                    .activations
-                    .iter()
-                    .map(|b| if *b { F::one() } else { F::zero() })
-                    .collect::<Vec<_>>();
-                let combination_index = combination_assignments.len();
-                combination_assignments.push(combination_assignment);
-                selector_assignments.push(SelectorAssignment {
-                    selector: selector.selector,
-                    combination_index,
-                    expression,
-                });
+            let combination_assignment = selector
+                .activations
+                .iter()
+                .map(|b| if *b { F::one() } else { F::zero() })
+                .collect::<Vec<_>>();
+            let combination_index = combination_assignments.len();
+            combination_assignments.push(combination_assignment);
+            selector_assignments.push(SelectorAssignment {
+                selector: selector.selector,
+                combination_index,
+                expression,
+            });
 
-                false
-            } else {
-                true
-            }
-        })
-        .collect();
+            false
+        } else {
+            true
+        }
+    });
 
     // All of the remaining `selectors` are simple. Let's try to combine them.
     // First, we compute the exclusion matrix that has (j, k) = true if selector
diff --git a/halo2_proofs/src/plonk/lookup/prover.rs b/halo2_proofs/src/plonk/lookup/prover.rs
index a29c6441..2b08bf14 100644
--- a/halo2_proofs/src/plonk/lookup/prover.rs
+++ b/halo2_proofs/src/plonk/lookup/prover.rs
@@ -613,7 +613,7 @@ fn permute_expression_pair<C: CurveAffine, R: RngCore>(
     // Populate permuted table at unfilled rows with leftover table elements
     for (coeff, count) in leftover_table_map.iter() {
         for _ in 0..*count {
-            permuted_table_coeffs[repeated_input_rows.pop().unwrap() as usize] = *coeff;
+            permuted_table_coeffs[repeated_input_rows.pop().unwrap()] = *coeff;
         }
     }
     assert!(repeated_input_rows.is_empty());
diff --git a/halo2_proofs/src/plonk/permutation/prover.rs b/halo2_proofs/src/plonk/permutation/prover.rs
index 84971173..2d792d60 100644
--- a/halo2_proofs/src/plonk/permutation/prover.rs
+++ b/halo2_proofs/src/plonk/permutation/prover.rs
@@ -128,7 +128,7 @@ impl Argument {
                     Any::Instance => instance,
                 };
                 parallelize(&mut modified_values, |modified_values, start| {
-                    let mut deltaomega = deltaomega * &omega.pow_vartime(&[start as u64, 0, 0, 0]);
+                    let mut deltaomega = deltaomega * &omega.pow_vartime([start as u64, 0, 0, 0]);
                     for (modified_values, value) in modified_values
                         .iter_mut()
                         .zip(values[column.index()][start..].iter())
@@ -292,7 +292,7 @@ impl<C: CurveAffine, Ev: Copy + Send + Sync> Committed<C, Ev> {
 
                         let mut right = poly::Ast::from(set.permutation_product_coset);
                         let mut current_delta = *beta
-                            * &(C::Scalar::DELTA.pow_vartime(&[(chunk_index * chunk_len) as u64]));
+                            * &(C::Scalar::DELTA.pow_vartime([(chunk_index * chunk_len) as u64]));
                         for values in columns.iter().map(|&column| match column.column_type() {
                             Any::Advice => &advice_cosets[column.index()],
                             Any::Fixed => &fixed_cosets[column.index()],
diff --git a/halo2_proofs/src/plonk/permutation/verifier.rs b/halo2_proofs/src/plonk/permutation/verifier.rs
index 001e1230..d3e8808c 100644
--- a/halo2_proofs/src/plonk/permutation/verifier.rs
+++ b/halo2_proofs/src/plonk/permutation/verifier.rs
@@ -179,7 +179,7 @@ impl<C: CurveAffine> Evaluated<C> {
 
                         let mut right = set.permutation_product_eval;
                         let mut current_delta = (*beta * &*x)
-                            * &(C::Scalar::DELTA.pow_vartime(&[(chunk_index * chunk_len) as u64]));
+                            * &(C::Scalar::DELTA.pow_vartime([(chunk_index * chunk_len) as u64]));
                         for eval in columns.iter().map(|&column| match column.column_type() {
                             Any::Advice => {
                                 advice_evals[vk.cs.get_any_query_index(column, Rotation::cur())]
diff --git a/halo2_proofs/src/plonk/prover.rs b/halo2_proofs/src/plonk/prover.rs
index 209d75c0..304244e8 100644
--- a/halo2_proofs/src/plonk/prover.rs
+++ b/halo2_proofs/src/plonk/prover.rs
@@ -596,7 +596,7 @@ pub fn create_proof<
     )?;
 
     let x: ChallengeX<_> = transcript.squeeze_challenge_scalar();
-    let xn = x.pow(&[params.n as u64, 0, 0, 0]);
+    let xn = x.pow(&[params.n, 0, 0, 0]);
 
     // Compute and hash instance evals for each circuit instance
     for instance in instance.iter() {
diff --git a/halo2_proofs/src/plonk/verifier.rs b/halo2_proofs/src/plonk/verifier.rs
index 6bb2c0a6..98916cbb 100644
--- a/halo2_proofs/src/plonk/verifier.rs
+++ b/halo2_proofs/src/plonk/verifier.rs
@@ -203,7 +203,7 @@ pub fn verify_proof<
     // commitments open to the correct values.
     let vanishing = {
         // x^n
-        let xn = x.pow(&[params.n as u64, 0, 0, 0]);
+        let xn = x.pow(&[params.n, 0, 0, 0]);
 
         let blinding_factors = vk.cs.blinding_factors();
         let l_evals = vk
diff --git a/halo2_proofs/src/poly.rs b/halo2_proofs/src/poly.rs
index 81c0525e..95170a06 100644
--- a/halo2_proofs/src/poly.rs
+++ b/halo2_proofs/src/poly.rs
@@ -304,7 +304,7 @@ impl<F: Field, B: Basis> Mul<F> for Polynomial<F, B> {
 /// Describes the relative rotation of a vector. Negative numbers represent
 /// reverse (leftmost) rotations and positive numbers represent forward (rightmost)
 /// rotations. Zero represents no rotation.
-#[derive(Copy, Clone, Debug, PartialEq)]
+#[derive(Copy, Clone, Debug, PartialEq, Eq)]
 pub struct Rotation(pub i32);
 
 impl Rotation {
diff --git a/halo2_proofs/src/poly/commitment.rs b/halo2_proofs/src/poly/commitment.rs
index 06283f9b..80c8b093 100644
--- a/halo2_proofs/src/poly/commitment.rs
+++ b/halo2_proofs/src/poly/commitment.rs
@@ -82,7 +82,7 @@ impl<C: CurveAffine> Params<C> {
         }
         let mut g_lagrange_projective = g_projective;
         best_fft(&mut g_lagrange_projective, alpha_inv, k);
-        let minv = C::Scalar::TWO_INV.pow_vartime(&[k as u64, 0, 0, 0]);
+        let minv = C::Scalar::TWO_INV.pow_vartime([k as u64, 0, 0, 0]);
         parallelize(&mut g_lagrange_projective, |g, _| {
             for g in g.iter_mut() {
                 *g *= minv;
diff --git a/halo2_proofs/src/poly/domain.rs b/halo2_proofs/src/poly/domain.rs
index d83ce78e..9e0398b7 100644
--- a/halo2_proofs/src/poly/domain.rs
+++ b/halo2_proofs/src/poly/domain.rs
@@ -85,8 +85,8 @@ impl<F: FieldExt> EvaluationDomain<F> {
         {
             // Compute the evaluations of t(X) = X^n - 1 in the coset evaluation domain.
             // We don't have to compute all of them, because it will repeat.
-            let orig = F::ZETA.pow_vartime(&[n as u64, 0, 0, 0]);
-            let step = extended_omega.pow_vartime(&[n as u64, 0, 0, 0]);
+            let orig = F::ZETA.pow_vartime([n, 0, 0, 0]);
+            let step = extended_omega.pow_vartime([n, 0, 0, 0]);
             let mut cur = orig;
             loop {
                 t_evaluations.push(cur);
@@ -404,11 +404,11 @@ impl<F: FieldExt> EvaluationDomain<F> {
     pub fn rotate_omega(&self, value: F, rotation: Rotation) -> F {
         let mut point = value;
         if rotation.0 >= 0 {
-            point *= &self.get_omega().pow_vartime(&[rotation.0 as u64]);
+            point *= &self.get_omega().pow_vartime([rotation.0 as u64]);
         } else {
             point *= &self
                 .get_omega_inv()
-                .pow_vartime(&[(rotation.0 as i64).unsigned_abs()]);
+                .pow_vartime([(rotation.0 as i64).unsigned_abs()]);
         }
         point
     }
diff --git a/halo2_proofs/src/poly/evaluator.rs b/halo2_proofs/src/poly/evaluator.rs
index 8f2b2014..04f509d3 100644
--- a/halo2_proofs/src/poly/evaluator.rs
+++ b/halo2_proofs/src/poly/evaluator.rs
@@ -540,7 +540,7 @@ impl BasisOps for LagrangeCoeff {
         let omega = domain.get_omega();
         let start = chunk_size * chunk_index;
         (0..cmp::min(chunk_size, poly_len - start))
-            .scan(omega.pow_vartime(&[start as u64]) * scalar, |acc, _| {
+            .scan(omega.pow_vartime([start as u64]) * scalar, |acc, _| {
                 let ret = *acc;
                 *acc *= omega;
                 Some(ret)
@@ -585,7 +585,7 @@ impl BasisOps for ExtendedLagrangeCoeff {
         let start = chunk_size * chunk_index;
         (0..cmp::min(chunk_size, poly_len - start))
             .scan(
-                omega.pow_vartime(&[start as u64]) * F::ZETA * scalar,
+                omega.pow_vartime([start as u64]) * F::ZETA * scalar,
                 |acc, _| {
                     let ret = *acc;
                     *acc *= omega;