Update to Rust 2018 (#184)

* Migrate to Rust 2018

* Remove rust-toolchain file

The toolchains tested on CI are specified in their own ways, so this is only
used for local builds where developers. Its better for developers not to have
this file around in case they have their own preferences.

.gitignore

@@ -28,5 +28,6 @@ tmp
 harness/target
 
 Cargo.lock
+rust-toolchain
 *.rs.bk
 *.rs.fmt

Cargo.toml

@@ -10,6 +10,7 @@ homepage = "https://github.com/pingcap/raft-rs"
 documentation = "https://docs.rs/raft"
 description = "The rust language implementation of Raft algorithm."
 categories = ["algorithms", "database-implementations"]
+edition = "2018"
 
 [features]
 default = []

benches/benches.rs

@@ -1,10 +1,6 @@
 #![allow(dead_code)] // Due to criterion we need this to avoid warnings.
 #![cfg_attr(feature = "cargo-clippy", allow(clippy::let_and_return))] // Benches often artificially return values. Allow it.
 
-extern crate criterion;
-extern crate env_logger;
-extern crate raft;
-
 use criterion::Criterion;
 use std::time::Duration;
 

benches/suites/progress_set.rs

@@ -1,6 +1,6 @@
+use crate::DEFAULT_RAFT_SETS;
 use criterion::{Bencher, Criterion};
 use raft::{Progress, ProgressSet};
-use DEFAULT_RAFT_SETS;
 
 pub fn bench_progress_set(c: &mut Criterion) {
     bench_progress_set_new(c);

benches/suites/raft.rs

@@ -1,6 +1,6 @@
+use crate::DEFAULT_RAFT_SETS;
 use criterion::{Bencher, Criterion};
 use raft::{storage::MemStorage, Config, Raft};
-use DEFAULT_RAFT_SETS;
 
 pub fn bench_raft(c: &mut Criterion) {
     bench_raft_new(c);

examples/single_mem_node/main.rs

@@ -11,7 +11,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-extern crate raft;
+use raft;
 
 use std::collections::HashMap;
 use std::sync::mpsc::{self, RecvTimeoutError};
@@ -21,7 +21,7 @@ use std::time::{Duration, Instant};
 use raft::prelude::*;
 use raft::storage::MemStorage;
 
-type ProposeCallback = Box<Fn() + Send>;
+type ProposeCallback = Box<dyn Fn() + Send>;
 
 enum Msg {
     Propose {

generate-proto.sh

@@ -11,3 +11,5 @@ res = re.sub('::protobuf::rt::read_proto3_enum_with_unknown_fields_into\(([^,]+)
 with open("src/eraftpb.rs", "w") as writer:
     writer.write(res)
 EOF
+
+cargo fix --edition-idioms --allow-dirty