Migrate to 2021 edition

Cargo.toml

@@ -8,7 +8,7 @@ authors = [
     "Ying Tong Lai <yingtong@electriccoin.co>",
     "Kris Nuttycombe <kris@electriccoin.co>",
 ]
-edition = "2018"
+edition = "2021"
 rust-version = "1.56.1"
 description = "[BETA] The Orchard shielded transaction protocol"
 license-file = "LICENSE-BOSL"

benches/note_decryption.rs

@@ -1,5 +1,3 @@
-use std::array;
-
 use criterion::{criterion_group, criterion_main, BenchmarkId, Criterion, Throughput};
 use orchard::{
     builder::Builder,
@@ -116,7 +114,7 @@ fn bench_note_decryption(c: &mut Criterion) {
 
         let mut group = c.benchmark_group("batch-note-decryption");
 
-        for size in array::IntoIter::new([10, 50, 100]) {
+        for size in [10, 50, 100] {
             group.throughput(Throughput::Elements((ivks * size) as u64));
 
             group.bench_function(BenchmarkId::new("valid", size), |b| {

src/address.rs

@@ -1,5 +1,3 @@
-use std::convert::TryInto;
-
 use subtle::CtOption;
 
 use crate::{

src/builder.rs

@@ -1,6 +1,5 @@
 //! Logic for building Orchard components of transactions.
 
-use std::convert::TryFrom;
 use std::fmt;
 use std::iter;
 

src/bundle.rs

@@ -2,7 +2,6 @@
 
 pub mod commitments;
 
-use std::convert::TryInto;
 use std::fmt;
 use std::io;
 

src/circuit.rs

@@ -52,8 +52,6 @@ use halo2_gadgets::{
     utilities::{lookup_range_check::LookupRangeCheckConfig, UtilitiesInstructions},
 };
 
-use std::convert::TryInto;
-
 mod commit_ivk;
 pub mod gadget;
 mod note_commit;
@@ -163,7 +161,7 @@ impl plonk::Circuit<pallas::Base> for Circuit {
             let not_enable_spends = one.clone() - meta.query_advice(advices[6], Rotation::cur());
             let not_enable_outputs = one - meta.query_advice(advices[7], Rotation::cur());
 
-            std::array::IntoIter::new([
+            [
                 (
                     "v_old - v_new = magnitude * sign",
                     v_old.clone() - v_new.clone() - magnitude * sign,
@@ -177,7 +175,7 @@ impl plonk::Circuit<pallas::Base> for Circuit {
                     "v_new = 0 or enable_outputs = 1",
                     v_new * not_enable_outputs,
                 ),
-            ])
+            ]
             .map(move |(name, poly)| (name, q_orchard.clone() * poly))
         });
 
@@ -1029,7 +1027,6 @@ mod tests {
 
     #[test]
     fn serialized_proof_test_case() {
-        use std::convert::TryInto;
         use std::io::{Read, Write};
 
         let vk = VerifyingKey::build();

src/circuit/commit_ivk.rs

@@ -652,8 +652,6 @@ mod tests {
     use pasta_curves::{arithmetic::FieldExt, pallas};
     use rand::rngs::OsRng;
 
-    use std::convert::TryInto;
-
     #[test]
     fn commit_ivk() {
         #[derive(Default)]

src/circuit/note_commit.rs

@@ -1480,7 +1480,6 @@ mod tests {
     };
 
     use rand::{rngs::OsRng, RngCore};
-    use std::convert::TryInto;
 
     #[test]
     fn note_commit() {

src/constants/load.rs

@@ -1,5 +1,3 @@
-use std::convert::TryInto;
-
 use crate::constants::{self, compute_lagrange_coeffs, H, NUM_WINDOWS, NUM_WINDOWS_SHORT};
 use group::ff::PrimeField;
 use pasta_curves::pallas;

src/keys.rs

@@ -1,7 +1,5 @@
 //! Key structures for Orchard.
 
-use std::array;
-use std::convert::{TryFrom, TryInto};
 use std::io::{self, Read, Write};
 use std::mem;
 
@@ -389,7 +387,8 @@ impl FullViewingKey {
     /// Returns the scope of the given address, or `None` if the address is not derived
     /// from this full viewing key.
     pub fn scope_for_address(&self, address: &Address) -> Option<Scope> {
-        array::IntoIter::new([Scope::External, Scope::Internal])
+        [Scope::External, Scope::Internal]
+            .into_iter()
             .find(|scope| self.to_ivk(*scope).diversifier_index(address).is_some())
     }
 

src/note/nullifier.rs

@@ -66,7 +66,6 @@ pub mod testing {
     use pasta_curves::{arithmetic::FieldExt, pallas};
     use proptest::collection::vec;
     use proptest::prelude::*;
-    use std::convert::TryFrom;
 
     use super::Nullifier;
     use crate::spec::extract_p;

src/note_encryption.rs

@@ -1,6 +1,6 @@
 //! In-band secret distribution for Orchard bundles.
 
-use std::{convert::TryInto, fmt};
+use std::fmt;
 
 use blake2b_simd::{Hash, Params};
 use group::ff::PrimeField;

src/primitives/redpallas.rs

@@ -1,7 +1,6 @@
 //! A minimal RedPallas implementation for use in Zcash.
 
 use std::cmp::{Ord, Ordering, PartialOrd};
-use std::convert::{TryFrom, TryInto};
 
 use pasta_curves::pallas;
 use rand::{CryptoRng, RngCore};
@@ -184,8 +183,6 @@ pub(crate) mod private {
 #[cfg(any(test, feature = "test-dependencies"))]
 #[cfg_attr(docsrs, doc(cfg(feature = "test-dependencies")))]
 pub mod testing {
-    use std::convert::TryFrom;
-
     use proptest::prelude::*;
 
     use super::{Binding, SigningKey, SpendAuth, VerificationKey};

src/spec.rs

@@ -276,7 +276,6 @@ mod tests {
     use halo2_proofs::arithmetic::CurveExt;
     use pasta_curves::pallas;
     use rand::{rngs::OsRng, RngCore};
-    use std::convert::TryInto;
 
     #[test]
     fn diversify_hash_substitution() {

src/tree.rs

@@ -86,8 +86,6 @@ pub struct MerklePath {
 #[cfg_attr(docsrs, doc(cfg(feature = "test-dependencies")))]
 impl From<(incrementalmerkletree::Position, Vec<MerkleHashOrchard>)> for MerklePath {
     fn from(path: (incrementalmerkletree::Position, Vec<MerkleHashOrchard>)) -> Self {
-        use std::convert::TryInto;
-
         let position: u64 = path.0.into();
         Self {
             position: position as u32,
@@ -266,8 +264,6 @@ pub mod testing {
     use group::ff::PrimeField;
     #[cfg(test)]
     use pasta_curves::pallas;
-    #[cfg(test)]
-    use std::convert::TryInto;
 
     #[test]
     fn test_vectors() {

src/value.rs

@@ -35,7 +35,6 @@
 //! [`Builder::add_recipient`]: crate::builder::Builder::add_recipient
 //! [Rust documentation]: https://doc.rust-lang.org/stable/std/primitive.i64.html
 
-use std::convert::{TryFrom, TryInto};
 use std::fmt::{self, Debug};
 use std::iter::Sum;
 use std::ops::{Add, Sub};

src/zip32.rs

@@ -1,9 +1,6 @@
 //! Key structures for Orchard.
 
-use std::{
+use std::fmt;
-    convert::{TryFrom, TryInto},
-    fmt,
-};
 
 use blake2b_simd::Params as Blake2bParams;
 use subtle::{Choice, ConstantTimeEq};

tests/builder.rs

@@ -1,5 +1,3 @@
-use std::convert::TryInto;
-
 use incrementalmerkletree::{bridgetree::BridgeTree, Frontier, Hashable, Tree};
 use orchard::{
     builder::Builder,