Upgrade to Rust 1.31.0 and edition 2018.

.travis.yml

@@ -1,6 +1,6 @@
 language: rust
 rust:
-    - 1.30.0
+    - 1.31.0
 cache:
   cargo: true
   timeout: 1200

Cargo.toml

@@ -16,6 +16,7 @@ license = "MIT/Apache-2.0"
 readme = "README.md"
 repository = "https://github.com/poanetwork/threshold_crypto"
 description = "Pairing threshold cryptography"
+edition = "2018"
 
 [dependencies]
 byteorder = "1.2.7"

benches/bench.rs

@@ -1,8 +1,3 @@
-extern crate criterion;
-extern crate pairing;
-extern crate rand;
-extern crate threshold_crypto;
-
 use criterion::{criterion_group, criterion_main, Criterion};
 use threshold_crypto::poly::Poly;
 use threshold_crypto::Fr;
@@ -79,7 +74,7 @@ mod poly_benches {
         );
     }
 
-    criterion_group!{
+    criterion_group! {
         name = poly_benches;
         config = Criterion::default();
         targets = multiplication, interpolate, addition, subtraction,
@@ -108,7 +103,8 @@ mod public_key_set_benches {
                     .map(|&i| {
                         let sig = sk_set.secret_key_share(i).sign(msg);
                         (i, sig)
-                    }).collect();
+                    })
+                    .collect();
                 b.iter(|| {
                     pk_set
                         .combine_signatures(&sigs)
@@ -119,7 +115,7 @@ mod public_key_set_benches {
         );
     }
 
-    criterion_group!{
+    criterion_group! {
         name = public_key_set_benches;
         config = Criterion::default();
         targets = combine_signatures,

examples/basic_pkc.rs

@@ -1,7 +1,3 @@
-extern crate bincode;
-extern crate serde_derive;
-extern crate threshold_crypto;
-
 use bincode::{deserialize, serialize};
 use serde_derive::{Deserialize, Serialize};
 use threshold_crypto::{PublicKey, SecretKey, Signature};

examples/threshold_enc.rs

@@ -1,6 +1,3 @@
-extern crate rand;
-extern crate threshold_crypto;
-
 use std::collections::BTreeMap;
 
 use threshold_crypto::{
@@ -35,7 +32,8 @@ impl SecretSociety {
                 let sk_share = sk_set.secret_key_share(id);
                 let pk_share = pk_set.public_key_share(id);
                 Actor::new(id, sk_share, pk_share)
-            }).collect();
+            })
+            .collect();
 
         SecretSociety { actors, pk_set }
     }

examples/threshold_sig.rs

@@ -1,6 +1,3 @@
-extern crate rand;
-extern crate threshold_crypto;
-
 use std::collections::BTreeMap;
 
 use threshold_crypto::{
@@ -53,7 +50,8 @@ impl ChatNetwork {
                 let sk_share = sk_set.secret_key_share(id);
                 let pk_share = pk_set.public_key_share(id);
                 Node::new(id, sk_share, pk_share)
-            }).collect();
+            })
+            .collect();
 
         ChatNetwork {
             pk_set,
@@ -98,8 +96,7 @@ impl ChatNetwork {
                 .iter()
                 .fold(BTreeMap::new(), |mut all_pending, node| {
                     for (user_id, signed_msgs) in &node.pending {
-                        let mut user_msgs =
-                            all_pending.entry(*user_id).or_insert_with(BTreeMap::new);
+                        let user_msgs = all_pending.entry(*user_id).or_insert_with(BTreeMap::new);
                         for (msg, sigs) in signed_msgs.iter() {
                             let sigs = sigs.iter().cloned();
                             user_msgs

src/lib.rs

@@ -2,34 +2,15 @@
 
 // Clippy warns that it's dangerous to derive `PartialEq` and explicitly implement `Hash`, but the
 // `pairing::bls12_381` types don't implement `Hash`, so we can't derive it.
-#![cfg_attr(feature = "cargo-clippy", allow(derive_hash_xor_eq))]
+#![allow(clippy::derive_hash_xor_eq)]
 // When using the mocktography, the resulting field elements become wrapped `u32`s, suddenly
 // triggering pass-by-reference warnings. They are conditionally disabled for this reason:
 #![cfg_attr(
-    all(
-        feature = "cargo-clippy",
-        feature = "use-insecure-test-only-mock-crypto"
-    ),
-    allow(trivially_copy_pass_by_ref)
+    feature = "use-insecure-test-only-mock-crypto",
+    allow(clippy::trivially_copy_pass_by_ref)
 )]
 #![warn(missing_docs)]
 
-#[cfg(test)]
-extern crate bincode;
-extern crate byteorder;
-extern crate errno;
-extern crate failure;
-extern crate hex_fmt;
-extern crate init_with;
-extern crate lazy_static;
-extern crate log;
-extern crate memsec;
-extern crate rand;
-extern crate rand_derive;
-extern crate serde;
-extern crate serde_derive;
-extern crate tiny_keccak;
-
 pub extern crate pairing;
 
 mod into_fr;
@@ -50,13 +31,13 @@ use log::debug;
 use pairing::{CurveAffine, CurveProjective, EncodedPoint, Engine, Field};
 use rand::{ChaChaRng, OsRng, Rand, Rng, SeedableRng};
 use rand_derive::Rand;
+use serde_derive::{Deserialize, Serialize};
 use tiny_keccak::sha3_256;
 
-use error::{Error, FromBytesError, FromBytesResult, Result};
-use into_fr::IntoFr;
-use poly::{Commitment, Poly};
-use secret::{clear_fr, ContainsSecret, MemRange, FR_SIZE};
-use serde_derive::{Deserialize, Serialize};
+use crate::error::{Error, FromBytesError, FromBytesResult, Result};
+use crate::into_fr::IntoFr;
+use crate::poly::{Commitment, Poly};
+use crate::secret::{clear_fr, ContainsSecret, MemRange, FR_SIZE};
 
 #[cfg(not(feature = "use-insecure-test-only-mock-crypto"))]
 pub use pairing::bls12_381::{Bls12 as PEngine, Fr, FrRepr, G1Affine, G2Affine, G1, G2};
@@ -65,7 +46,7 @@ pub use pairing::bls12_381::{Bls12 as PEngine, Fr, FrRepr, G1Affine, G2Affine, G
 mod mock;
 
 #[cfg(feature = "use-insecure-test-only-mock-crypto")]
-pub use mock::{
+pub use crate::mock::{
     Mersenne8 as Fr, Mersenne8 as FrRepr, Mocktography as PEngine, Ms8Affine as G1Affine,
     Ms8Affine as G2Affine, Ms8Projective as G1, Ms8Projective as G2, PK_SIZE, SIG_SIZE,
 };
@@ -753,7 +734,8 @@ mod tests {
             .map(|&i| {
                 let sig = sk_set.secret_key_share(i).sign(msg);
                 (i, sig)
-            }).collect();
+            })
+            .collect();
 
         // Each of the shares is a valid signature matching its public key share.
         for (i, sig) in &sigs {
@@ -770,7 +752,8 @@ mod tests {
             .map(|&i| {
                 let sig = sk_set.secret_key_share(i).sign(msg);
                 (i, sig)
-            }).collect();
+            })
+            .collect();
         let sig2 = pk_set.combine_signatures(&sigs2).expect("signatures match");
         assert_eq!(sig, sig2);
     }
@@ -824,7 +807,8 @@ mod tests {
                     .decrypt_share(&ciphertext)
                     .expect("ciphertext is invalid");
                 (i, dec_share)
-            }).collect();
+            })
+            .collect();
 
         // Each of the shares is valid matching its public key share.
         for (i, share) in &shares {

src/mock/mod.rs

@@ -295,10 +295,10 @@ impl EncodedPoint for Ms8Affine {
 #[cfg(test)]
 mod test {
     // There are copy & pasted results of calculations from external programs in these tests.
-    #![cfg_attr(feature = "cargo-clippy", allow(unreadable_literal))]
+    #![allow(clippy::unreadable_literal)]
 
     use super::{EncodedPoint, Mersenne8, Mocktography, Ms8Affine, PK_SIZE, SIG_SIZE};
-    use Engine;
+    use pairing::Engine;
 
     #[test]
     fn example_pairings() {

src/mock/ms8.rs

@@ -428,13 +428,13 @@ fn ext_euclid(a: u32, b: u32) -> (u32, i64, i64) {
 #[cfg(test)]
 mod tests {
     // There are copy & pasted results of calculations from external programs in these tests.
-    #![cfg_attr(feature = "cargo-clippy", allow(unreadable_literal))]
-    #![cfg_attr(feature = "cargo-clippy", allow(op_ref))]
+    #![allow(clippy::unreadable_literal)]
+    #![allow(clippy::op_ref)]
     // We test a few mathematical identities, including `c - c = 0`. Clippy complains about these
     // otherwise unusual expressions, so the lint is disabled.
-    #![cfg_attr(feature = "cargo-clippy", allow(eq_op))]
+    #![allow(clippy::eq_op)]
     // Some test functions contain long lists of assertions. Clippy thinks they are too complex.
-    #![cfg_attr(feature = "cargo-clippy", allow(cyclomatic_complexity))]
+    #![allow(clippy::cyclomatic_complexity)]
 
     use super::{ext_euclid, modular_pow, Mersenne8};
     use pairing::Field;

src/poly.rs

@@ -26,10 +26,10 @@ use pairing::{CurveAffine, CurveProjective, Field};
 use rand::Rng;
 use serde_derive::{Deserialize, Serialize};
 
-use error::{Error, Result};
-use into_fr::IntoFr;
-use secret::{clear_fr, ContainsSecret, MemRange, Safe};
-use {Fr, G1Affine, G1};
+use crate::error::{Error, Result};
+use crate::into_fr::IntoFr;
+use crate::secret::{clear_fr, ContainsSecret, MemRange, Safe};
+use crate::{Fr, G1Affine, G1};
 
 /// A univariate polynomial in the prime field.
 #[derive(Serialize, Deserialize, PartialEq, Eq)]
@@ -53,7 +53,7 @@ impl Debug for Poly {
     }
 }
 
-#[cfg_attr(feature = "cargo-clippy", allow(suspicious_op_assign_impl))]
+#[allow(clippy::suspicious_op_assign_impl)]
 impl<B: Borrow<Poly>> ops::AddAssign<B> for Poly {
     fn add_assign(&mut self, rhs: B) {
         let len = self.coeff.len();
@@ -139,7 +139,7 @@ impl<B: Borrow<Poly>> ops::Sub<B> for Poly {
 }
 
 // Clippy thinks using `+` in a `Sub` implementation is suspicious.
-#[cfg_attr(feature = "cargo-clippy", allow(suspicious_arithmetic_impl))]
+#[allow(clippy::suspicious_arithmetic_impl)]
 impl<'a> ops::Sub<Fr> for Poly {
     type Output = Poly;
 
@@ -158,7 +158,7 @@ impl<'a> ops::Sub<u64> for Poly {
 }
 
 // Clippy thinks using any `+` and `-` in a `Mul` implementation is suspicious.
-#[cfg_attr(feature = "cargo-clippy", allow(suspicious_arithmetic_impl))]
+#[allow(clippy::suspicious_arithmetic_impl)]
 impl<'a, B: Borrow<Poly>> ops::Mul<B> for &'a Poly {
     type Output = Poly;
 
@@ -406,7 +406,7 @@ impl Poly {
             // current value at `x`: Adding it to `poly` will then make it correct for `x`.
             let mut diff = *y;
             diff.sub_assign(&poly.evaluate(x));
-            let mut base_val = base.evaluate(x);
+            let base_val = base.evaluate(x);
             diff.mul_assign(&base_val.inverse().expect("sample points must be distinct"));
             base *= diff;
             poly += &base;
@@ -608,7 +608,8 @@ impl BivarPoly {
                     result.add_assign(&summand);
                 }
                 result
-            }).collect();
+            })
+            .collect();
         Poly::from(coeff)
     }
 
@@ -692,7 +693,8 @@ impl BivarCommitment {
                     result.add_assign(&summand);
                 }
                 result
-            }).collect();
+            })
+            .collect();
         Commitment { coeff }
     }
 
@@ -710,7 +712,8 @@ fn powers<T: IntoFr>(into_x: T, degree: usize) -> Vec<Fr> {
         .chain((0..degree).map(|_| {
             x_pow_i.mul_assign(&x);
             x_pow_i
-        })).collect()
+        }))
+        .collect()
 }
 
 /// Returns the position of coefficient `(i, j)` in the vector describing a symmetric bivariate

src/secret.rs

@@ -7,7 +7,7 @@ use std::ops::{Deref, DerefMut};
 use lazy_static::lazy_static;
 use memsec::memzero;
 
-use Fr;
+use crate::Fr;
 
 lazy_static! {
     /// The size in bytes of a single field element.

src/serde_impl.rs

@@ -1,11 +1,11 @@
 use std::borrow::Cow;
 
+use crate::G1;
 use serde::de::Error as DeserializeError;
 use serde::{Deserialize, Deserializer, Serialize, Serializer};
 use serde_derive::{Deserialize, Serialize};
-use G1;
 
-use poly::{coeff_pos, BivarCommitment};
+use crate::poly::{coeff_pos, BivarCommitment};
 
 const ERR_DEG: &str = "commitment degree does not match coefficients";
 
@@ -24,7 +24,8 @@ impl Serialize for BivarCommitment {
         WireBivarCommitment {
             degree: self.degree,
             coeff: Cow::Borrowed(&self.coeff),
-        }.serialize(s)
+        }
+        .serialize(s)
     }
 }
 
@@ -160,7 +161,7 @@ pub mod field_vec {
     use serde::de::Error as DeserializeError;
     use serde::{Deserialize, Deserializer, Serialize, Serializer};
 
-    use {Fr, FrRepr};
+    use crate::{Fr, FrRepr};
 
     /// A wrapper type to facilitate serialization and deserialization of field elements.
     pub struct FieldWrap<B>(B);
@@ -203,8 +204,8 @@ mod tests {
     use rand::{self, Rng};
     use serde_derive::{Deserialize, Serialize};
 
-    use poly::BivarPoly;
-    use {Fr, G1};
+    use crate::poly::BivarPoly;
+    use crate::{Fr, G1};
 
     #[derive(Debug, Serialize, Deserialize)]
     pub struct Vecs {