Use TryInto to convert slices into array

Remove dependency on `arrayref`.

Cargo.lock

@@ -25,11 +25,6 @@ dependencies = [
  "scoped_threadpool 0.1.9 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
-[[package]]
-name = "arrayref"
-version = "0.3.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-
 [[package]]
 name = "arrayvec"
 version = "0.4.10"
@@ -327,7 +322,6 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 name = "electrs"
 version = "0.5.0"
 dependencies = [
- "arrayref 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "base64 0.10.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "bincode 1.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "bitcoin 0.18.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1097,7 +1091,6 @@ dependencies = [
 "checksum aho-corasick 0.7.3 (registry+https://github.com/rust-lang/crates.io-index)" = "e6f484ae0c99fec2e858eb6134949117399f222608d84cadb3f58c1f97c2364c"
 "checksum ansi_term 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ee49baf6cb617b853aa8d93bf420db2383fab46d314482ca2803b40d5fde979b"
 "checksum argon2rs 0.2.5 (registry+https://github.com/rust-lang/crates.io-index)" = "3f67b0b6a86dae6e67ff4ca2b6201396074996379fba2b92ff649126f37cb392"
-"checksum arrayref 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)" = "0d382e583f07208808f6b1249e60848879ba3543f57c32277bf52d69c2f0f0ee"
 "checksum arrayvec 0.4.10 (registry+https://github.com/rust-lang/crates.io-index)" = "92c7fb76bc8826a8b33b4ee5bb07a247a81e76764ab4d55e8f73e3a4d8808c71"
 "checksum ascii 0.8.7 (registry+https://github.com/rust-lang/crates.io-index)" = "97be891acc47ca214468e09425d02cef3af2c94d0d82081cd02061f996802f14"
 "checksum atty 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)" = "9a7d5b8723950951411ee34d271d99dddcc2035a16ab25310ea2c8cfd4369652"

Cargo.toml

@@ -12,7 +12,6 @@ readme = "README.md"
 edition = "2018"
 
 [dependencies]
-arrayref = "0.3"
 base64 = "0.10"
 bincode = "1.0"
 bitcoin = "0.18"

doc/usage.md

@@ -1,6 +1,6 @@
 ## Installation
 
-Install [latest Rust](https://rustup.rs/) (1.33+),
+Install [latest Rust](https://rustup.rs/) (1.34+),
 [latest Bitcoin Core](https://bitcoincore.org/en/download/) (0.16+)
 and [latest Electrum wallet](https://electrum.org/#download) (3.3+).
 

src/lib.rs

@@ -5,8 +5,6 @@ extern crate chan;
 #[macro_use]
 extern crate clap;
 #[macro_use]
-extern crate arrayref;
-#[macro_use]
 extern crate error_chain;
 #[macro_use]
 extern crate log;

src/util.rs

@@ -2,6 +2,7 @@ use bitcoin::blockdata::block::BlockHeader;
 use bitcoin::util::hash::BitcoinHash;
 use bitcoin_hashes::sha256d::Hash as Sha256dHash;
 use std::collections::HashMap;
+use std::convert::TryInto;
 use std::fmt;
 use std::iter::FromIterator;
 use std::slice;
@@ -20,11 +21,13 @@ pub type FullHash = [u8; HASH_LEN];
 pub type HashPrefix = [u8; HASH_PREFIX_LEN];
 
 pub fn hash_prefix(hash: &[u8]) -> HashPrefix {
-    *array_ref![hash, 0, HASH_PREFIX_LEN]
+    hash[..HASH_PREFIX_LEN]
+        .try_into()
+        .expect("failed to convert into HashPrefix")
 }
 
 pub fn full_hash(hash: &[u8]) -> FullHash {
-    *array_ref![hash, 0, HASH_LEN]
+    hash.try_into().expect("failed to convert into FullHash")
 }
 
 #[derive(Eq, PartialEq, Clone)]