Fixing some clippy warnings (#1728)

* Fixing warnings

* Fixing unnecessary ref

* Removing unnecessary operation

ethcore/src/account_provider.rs

@@ -192,7 +192,7 @@ impl AccountProvider {
 	pub fn accounts_info(&self) -> Result<HashMap<H160, AccountMeta>, Error> {
 		let r: HashMap<H160, AccountMeta> = self.sstore.accounts()
 			.into_iter()
-			.map(|a| (H160(a.clone().into()), self.account_meta(a).unwrap_or(Default::default())))
+			.map(|a| (H160(a.clone().into()), self.account_meta(a).unwrap_or_else(|_| Default::default())))
 			.collect();
 		Ok(r)
 	}

ethcore/src/block.rs

@@ -339,7 +339,7 @@ impl<'x> OpenBlock<'x> {
 				let t = outcome.trace;
 				self.block.traces.as_mut().map(|traces| traces.push(t.expect("self.block.traces.is_some(): so we must be tracing: qed")));
 				self.block.receipts.push(outcome.receipt);
-				Ok(&self.block.receipts.last().unwrap())
+				Ok(self.block.receipts.last().unwrap())
 			}
 			Err(x) => Err(From::from(x))
 		}

ethcore/src/block_queue.rs

@@ -284,10 +284,10 @@ impl BlockQueue {
 
 	/// Check if the block is currently in the queue
 	pub fn block_status(&self, hash: &H256) -> BlockStatus {
-		if self.processing.read().contains(&hash) {
+		if self.processing.read().contains(hash) {
 			return BlockStatus::Queued;
 		}
-		if self.verification.bad.lock().contains(&hash) {
+		if self.verification.bad.lock().contains(hash) {
 			return BlockStatus::Bad;
 		}
 		BlockStatus::Unknown
@@ -340,7 +340,7 @@ impl BlockQueue {
 		bad.reserve(block_hashes.len());
 		for hash in block_hashes {
 			bad.insert(hash.clone());
-			processing.remove(&hash);
+			processing.remove(hash);
 		}
 
 		let mut new_verified = VecDeque::new();
@@ -362,7 +362,7 @@ impl BlockQueue {
 		}
 		let mut processing = self.processing.write();
 		for hash in block_hashes {
-			processing.remove(&hash);
+			processing.remove(hash);
 		}
 	}
 

ethcore/src/blockchain/blockchain.rs

@@ -512,7 +512,7 @@ impl BlockChain {
 
 		let _lock = self.insert_lock.lock();
 		// store block in db
-		self.blocks_db.put(&hash, &bytes).unwrap();
+		self.blocks_db.put(&hash, bytes).unwrap();
 
 		let info = self.block_info(bytes);
 
@@ -633,7 +633,7 @@ impl BlockChain {
 		if self.is_known(&first) {
 			Some(AncestryIter {
 				current: first,
-				chain: &self,
+				chain: self,
 			})
 		} else {
 			None

ethcore/src/client/client.rs

@@ -281,7 +281,7 @@ impl Client {
 		}
 
 		// Verify Block Family
-		let verify_family_result = self.verifier.verify_block_family(&header, &block.bytes, engine, self.chain.deref());
+		let verify_family_result = self.verifier.verify_block_family(header, &block.bytes, engine, self.chain.deref());
 		if let Err(e) = verify_family_result {
 			warn!(target: "client", "Stage 3 block verification failed for #{} ({})\nError: {:?}", header.number(), header.hash(), e);
 			return Err(());
@@ -299,7 +299,7 @@ impl Client {
 		let last_hashes = self.build_last_hashes(header.parent_hash.clone());
 		let db = self.state_db.lock().boxed_clone();
 
-		let enact_result = enact_verified(&block, engine, self.tracedb.tracing_enabled(), db, &parent, last_hashes, &self.vm_factory, self.trie_factory.clone());
+		let enact_result = enact_verified(block, engine, self.tracedb.tracing_enabled(), db, &parent, last_hashes, &self.vm_factory, self.trie_factory.clone());
 		if let Err(e) = enact_result {
 			warn!(target: "client", "Block import failed for #{} ({})\nError: {:?}", header.number(), header.hash(), e);
 			return Err(());
@@ -307,7 +307,7 @@ impl Client {
 
 		// Final Verification
 		let locked_block = enact_result.unwrap();
-		if let Err(e) = self.verifier.verify_block_final(&header, locked_block.block().header()) {
+		if let Err(e) = self.verifier.verify_block_final(header, locked_block.block().header()) {
 			warn!(target: "client", "Stage 4 block verification failed for #{} ({})\nError: {:?}", header.number(), header.hash(), e);
 			return Err(());
 		}
@@ -468,7 +468,7 @@ impl Client {
 	pub fn import_queued_transactions(&self, transactions: &[Bytes]) -> usize {
 		let _timer = PerfTimer::new("import_queued_transactions");
 		self.queue_transactions.fetch_sub(transactions.len(), AtomicOrdering::SeqCst);
-		let txs = transactions.iter().filter_map(|bytes| UntrustedRlp::new(&bytes).as_val().ok()).collect();
+		let txs = transactions.iter().filter_map(|bytes| UntrustedRlp::new(bytes).as_val().ok()).collect();
 		let results = self.miner.import_external_transactions(self, txs);
 		results.len()
 	}
@@ -684,7 +684,7 @@ impl BlockChainClient for Client {
 	}
 
 	fn block(&self, id: BlockID) -> Option<Bytes> {
-		if let &BlockID::Pending = &id {
+		if let BlockID::Pending = id {
 			if let Some(block) = self.miner.pending_block() {
 				return Some(block.rlp_bytes(Seal::Without));
 			}
@@ -703,7 +703,7 @@ impl BlockChainClient for Client {
 	}
 
 	fn block_total_difficulty(&self, id: BlockID) -> Option<U256> {
-		if let &BlockID::Pending = &id {
+		if let BlockID::Pending = id {
 			if let Some(block) = self.miner.pending_block() {
 				return Some(*block.header.difficulty() + self.block_total_difficulty(BlockID::Latest).expect("blocks in chain have details; qed"));
 			}

ethcore/src/client/config.rs

@@ -46,7 +46,7 @@ impl FromStr for DatabaseCompactionProfile {
 		match s {
 			"ssd" | "default" => Ok(DatabaseCompactionProfile::Default),
 			"hdd" => Ok(DatabaseCompactionProfile::HDD),
-			_ => Err(format!("Invalid compaction profile given. Expected hdd/ssd (default).")),
+			_ => Err("Invalid compaction profile given. Expected hdd/ssd (default).".into()),
 		}
 	}
 }

ethcore/src/client/test_client.rs

@@ -190,7 +190,7 @@ impl TestBlockChainClient {
 						gas_price: U256::one(),
 						nonce: U256::zero()
 					};
-					let signed_tx = tx.sign(&keypair.secret());
+					let signed_tx = tx.sign(keypair.secret());
 					txs.append(&signed_tx);
 					txs.out()
 				},
@@ -366,8 +366,8 @@ impl BlockChainClient for TestBlockChainClient {
 	fn block_body(&self, id: BlockID) -> Option<Bytes> {
 		self.block_hash(id).and_then(|hash| self.blocks.read().get(&hash).map(|r| {
 			let mut stream = RlpStream::new_list(2);
-			stream.append_raw(Rlp::new(&r).at(1).as_raw(), 1);
-			stream.append_raw(Rlp::new(&r).at(2).as_raw(), 1);
+			stream.append_raw(Rlp::new(r).at(1).as_raw(), 1);
+			stream.append_raw(Rlp::new(r).at(2).as_raw(), 1);
 			stream.out()
 		}))
 	}

ethcore/src/evm/interpreter/mod.rs

@@ -96,13 +96,13 @@ impl<Cost: CostType> evm::Evm for Interpreter<Cost> {
 		self.mem.clear();
 
 		let code = &params.code.as_ref().unwrap();
-		let valid_jump_destinations = self.find_jump_destinations(&code);
+		let valid_jump_destinations = self.find_jump_destinations(code);
 
 		let mut gasometer = Gasometer::<Cost>::new(try!(Cost::from_u256(params.gas)));
 		let mut stack = VecStack::with_capacity(ext.schedule().stack_limit, U256::zero());
 		let mut reader = CodeReader {
 			position: 0,
-			code: &code
+			code: code
 		};
 		let infos = &*instructions::INSTRUCTIONS;
 
@@ -274,7 +274,7 @@ impl<Cost: CostType> Interpreter<Cost> {
 					return Ok(InstructionResult::Ok);
 				}
 
-				let create_result = ext.create(&gas.as_u256(), &endowment, &contract_code);
+				let create_result = ext.create(&gas.as_u256(), &endowment, contract_code);
 				return match create_result {
 					ContractCreateResult::Created(address, gas_left) => {
 						stack.push(address_to_u256(address));

ethcore/src/executive.rs

@@ -370,7 +370,7 @@ impl<'a> Executive<'a> {
 		let gas = params.gas;
 		let created = params.address.clone();
 
-		let mut subvmtracer = vm_tracer.prepare_subtrace(&params.code.as_ref().expect("two ways into create (Externalities::create and Executive::transact_with_tracer); both place `Some(...)` `code` in `params`; qed"));
+		let mut subvmtracer = vm_tracer.prepare_subtrace(params.code.as_ref().expect("two ways into create (Externalities::create and Executive::transact_with_tracer); both place `Some(...)` `code` in `params`; qed"));
 
 		let res = {
 			self.exec_vm(params, &mut unconfirmed_substate, OutputPolicy::InitContract(trace_output.as_mut()), &mut subtracer, &mut subvmtracer)
@@ -1009,7 +1009,7 @@ mod tests {
 			gas: U256::from(100_000),
 			gas_price: U256::zero(),
 			nonce: U256::zero()
-		}.sign(&keypair.secret());
+		}.sign(keypair.secret());
 		let sender = t.sender().unwrap();
 		let contract = contract_address(&sender, &U256::zero());
 
@@ -1076,7 +1076,7 @@ mod tests {
 			gas: U256::from(100_000),
 			gas_price: U256::zero(),
 			nonce: U256::one()
-		}.sign(&keypair.secret());
+		}.sign(keypair.secret());
 		let sender = t.sender().unwrap();
 
 		let mut state_result = get_temp_state();
@@ -1109,7 +1109,7 @@ mod tests {
 			gas: U256::from(80_001),
 			gas_price: U256::zero(),
 			nonce: U256::zero()
-		}.sign(&keypair.secret());
+		}.sign(keypair.secret());
 		let sender = t.sender().unwrap();
 
 		let mut state_result = get_temp_state();
@@ -1144,7 +1144,7 @@ mod tests {
 			gas: U256::from(100_000),
 			gas_price: U256::one(),
 			nonce: U256::zero()
-		}.sign(&keypair.secret());
+		}.sign(keypair.secret());
 		let sender = t.sender().unwrap();
 
 		let mut state_result = get_temp_state();

ethcore/src/externalities.rs

@@ -272,7 +272,7 @@ impl<'a, T, V> Ext for Externalities<'a, T, V> where T: 'a + Tracer, V: 'a + VMT
 	}
 
 	fn env_info(&self) -> &EnvInfo {
-		&self.env_info
+		self.env_info
 	}
 
 	fn depth(&self) -> usize {
@@ -455,7 +455,7 @@ mod tests {
 		{
 			let vm_factory = Default::default();
 			let mut ext = Externalities::new(state, &setup.env_info, &*setup.engine, &vm_factory, 0, get_test_origin(), &mut setup.sub_state, OutputPolicy::InitContract(None), &mut tracer, &mut vm_tracer);
-			ext.suicide(&refund_account);
+			ext.suicide(refund_account);
 		}
 
 		assert_eq!(setup.sub_state.suicides.len(), 1);

ethcore/src/header.rs

@@ -234,7 +234,7 @@ impl Header {
 		s.append(&self.extra_data);
 		if let Seal::With = with_seal {
 			for b in &self.seal {
-				s.append_raw(&b, 1);
+				s.append_raw(b, 1);
 			}
 		}
 	}

ethcore/src/lib.rs

@@ -15,23 +15,20 @@
 // along with Parity.  If not, see <http://www.gnu.org/licenses/>.
 
 #![warn(missing_docs)]
+#![cfg_attr(feature="benches", feature(test))]
 #![cfg_attr(feature="dev", feature(plugin))]
 #![cfg_attr(feature="dev", plugin(clippy))]
 
-// Clippy config
-// TODO [todr] not really sure
+// Clippy settings
+// Most of the time much more readable
 #![cfg_attr(feature="dev", allow(needless_range_loop))]
 // Shorter than if-else
 #![cfg_attr(feature="dev", allow(match_bool))]
-// Keeps consistency (all lines with `.clone()`) and helpful when changing ref to non-ref.
+// Keeps consistency (all lines with `.clone()`).
 #![cfg_attr(feature="dev", allow(clone_on_copy))]
-// In most cases it expresses function flow better
-#![cfg_attr(feature="dev", allow(if_not_else))]
 // TODO [todr] a lot of warnings to be fixed
-#![cfg_attr(feature="dev", allow(needless_borrow))]
 #![cfg_attr(feature="dev", allow(assign_op_pattern))]
 
-#![cfg_attr(feature="benches", feature(test))]
 
 //! Ethcore library
 //!

ethcore/src/miner/work_notify.rs

@@ -35,7 +35,7 @@ pub struct WorkPoster {
 impl WorkPoster {
 	pub fn new(urls: &[String]) -> Self {
 		let urls = urls.into_iter().filter_map(|u| {
-			match Url::parse(&u) {
+			match Url::parse(u) {
 				Ok(url) => Some(url),
 				Err(e) => {
 					warn!("Error parsing URL {} : {}", u, e);

ethcore/src/pod_account.rs

@@ -143,8 +143,8 @@ pub fn diff_pod(pre: Option<&PodAccount>, post: Option<&PodAccount>) -> Option<A
 				},
 				storage: storage.into_iter().map(|k|
 					(k.clone(), Diff::new(
-						pre.storage.get(&k).cloned().unwrap_or_else(H256::new),
-						post.storage.get(&k).cloned().unwrap_or_else(H256::new)
+						pre.storage.get(k).cloned().unwrap_or_else(H256::new),
+						post.storage.get(k).cloned().unwrap_or_else(H256::new)
 					))).collect(),
 			};
 			if r.balance.is_same() && r.nonce.is_same() && r.code.is_same() && r.storage.is_empty() {

ethcore/src/service.rs

@@ -138,7 +138,7 @@ impl IoHandler<ClientIoMessage> for ClientIoHandler {
 	fn message(&self, _io: &IoContext<ClientIoMessage>, net_message: &ClientIoMessage) {
 		match *net_message {
 			ClientIoMessage::BlockVerified => { self.client.import_verified_blocks(); }
-			ClientIoMessage::NewTransactions(ref transactions) => { self.client.import_queued_transactions(&transactions); }
+			ClientIoMessage::NewTransactions(ref transactions) => { self.client.import_queued_transactions(transactions); }
 			_ => {} // ignore other messages
 		}
 	}
@@ -175,7 +175,7 @@ mod tests {
 		let service = ClientService::start(
 			ClientConfig::default(),
 			get_test_spec(),
-			&temp_path.as_path(),
+			temp_path.as_path(),
 			Arc::new(Miner::with_spec(get_test_spec())),
 		);
 		assert!(service.is_ok());

ethcore/src/state.rs

@@ -122,7 +122,7 @@ impl State {
 
 	fn insert_cache(&self, address: &Address, account: Option<Account>) {
 		if let Some(ref mut snapshot) = self.snapshots.borrow_mut().last_mut() {
-			if !snapshot.contains_key(&address) {
+			if !snapshot.contains_key(address) {
 				snapshot.insert(address.clone(), self.cache.borrow_mut().insert(address.clone(), account));
 				return;
 			}
@@ -132,7 +132,7 @@ impl State {
 
 	fn note_cache(&self, address: &Address) {
 		if let Some(ref mut snapshot) = self.snapshots.borrow_mut().last_mut() {
-			if !snapshot.contains_key(&address) {
+			if !snapshot.contains_key(address) {
 				snapshot.insert(address.clone(), self.cache.borrow().get(address).cloned());
 			}
 		}
@@ -151,7 +151,7 @@ impl State {
 	/// Create a new contract at address `contract`. If there is already an account at the address
 	/// it will have its code reset, ready for `init_code()`.
 	pub fn new_contract(&mut self, contract: &Address, balance: U256) {
-		self.insert_cache(&contract, Some(Account::new_contract(balance, self.account_start_nonce)));
+		self.insert_cache(contract, Some(Account::new_contract(balance, self.account_start_nonce)));
 	}
 
 	/// Remove an existing account.
@@ -162,7 +162,7 @@ impl State {
 	/// Determine whether an account exists.
 	pub fn exists(&self, a: &Address) -> bool {
 		let db = self.trie_factory.readonly(self.db.as_hashdb(), &self.root).expect(SEC_TRIE_DB_UNWRAP_STR);
-		self.cache.borrow().get(&a).unwrap_or(&None).is_some() || db.contains(&a)
+		self.cache.borrow().get(a).unwrap_or(&None).is_some() || db.contains(a)
 	}
 
 	/// Get the balance of account `a`.
@@ -329,7 +329,7 @@ impl State {
 		let have_key = self.cache.borrow().contains_key(a);
 		if !have_key {
 			let db = self.trie_factory.readonly(self.db.as_hashdb(), &self.root).expect(SEC_TRIE_DB_UNWRAP_STR);
-			self.insert_cache(a, db.get(&a).map(Account::from_rlp))
+			self.insert_cache(a, db.get(a).map(Account::from_rlp))
 		}
 		if require_code {
 			if let Some(ref mut account) = self.cache.borrow_mut().get_mut(a).unwrap().as_mut() {
@@ -350,7 +350,7 @@ impl State {
 		let have_key = self.cache.borrow().contains_key(a);
 		if !have_key {
 			let db = self.trie_factory.readonly(self.db.as_hashdb(), &self.root).expect(SEC_TRIE_DB_UNWRAP_STR);
-			self.insert_cache(a, db.get(&a).map(Account::from_rlp))
+			self.insert_cache(a, db.get(a).map(Account::from_rlp))
 		} else {
 			self.note_cache(a);
 		}

ethcore/src/verification/verification.rs

@@ -350,7 +350,7 @@ mod tests {
 			gas: U256::from(30_000),
 			gas_price: U256::from(40_000),
 			nonce: U256::one()
-		}.sign(&keypair.secret());
+		}.sign(keypair.secret());
 
 		let tr2 = Transaction {
 			action: Action::Create,
@@ -359,7 +359,7 @@ mod tests {
 			gas: U256::from(30_000),
 			gas_price: U256::from(40_000),
 			nonce: U256::from(2)
-		}.sign(&keypair.secret());
+		}.sign(keypair.secret());
 
 		let good_transactions = [ tr1.clone(), tr2.clone() ];
 

parity/configuration.rs

@@ -522,7 +522,7 @@ impl Configuration {
 			self.args.flag_geth ||
 			self.args.flag_no_signer;
 
-		return !signer_disabled;
+		!signer_disabled
 	}
 }
 

parity/helpers.rs

@@ -184,6 +184,7 @@ pub fn default_network_config() -> ::util::NetworkConfiguration {
 	}
 }
 
+#[cfg_attr(feature = "dev", allow(too_many_arguments))]
 pub fn to_client_config(
 		cache_config: &CacheConfig,
 		dirs: &Directories,
@@ -356,6 +357,7 @@ mod tests {
 	}
 
 	#[test]
+	#[cfg_attr(feature = "dev", allow(float_cmp))]
 	fn test_to_price() {
 		assert_eq!(to_price("1").unwrap(), 1.0);
 		assert_eq!(to_price("2.3").unwrap(), 2.3);

parity/informant.rs

@@ -160,7 +160,7 @@ impl ChainNotify for Informant {
 		let importing = queue_info.unverified_queue_size + queue_info.verified_queue_size > 3
 			|| self.sync.as_ref().map_or(false, |s| s.status().is_major_syncing());
 		if Instant::now() > *last_import + Duration::from_secs(1) && !importing {
-			if let Some(block) = imported.last().and_then(|h| self.client.block(BlockID::Hash(h.clone()))) {
+			if let Some(block) = imported.last().and_then(|h| self.client.block(BlockID::Hash(*h))) {
 				let view = BlockView::new(&block);
 				let header = view.header();
 				let tx_count = view.transactions_count();

parity/main.rs

@@ -113,7 +113,7 @@ fn start() -> Result<String, String> {
 
 fn main() {
 	// just redirect to the sync::main()
-	if std::env::args().nth(1).map(|arg| arg == "sync").unwrap_or(false) {
+	if std::env::args().nth(1).map_or(false, |arg| arg == "sync") {
 		sync::main();
 		return;
 	}

util/src/bytes.rs

@@ -195,7 +195,7 @@ pub trait Populatable {
 	/// If `d` is smaller, will leave some bytes untouched.
 	fn copy_raw(&mut self, d: &[u8]) {
 		use std::io::Write;
-		self.as_slice_mut().write(&d).unwrap();
+		self.as_slice_mut().write(d).unwrap();
 	}
 
 	/// Copies the raw representation of an object `d` to `self`, overwriting as necessary.

util/src/crypto.rs

@@ -273,7 +273,7 @@ pub mod ecdh {
 		let publ = try!(key::PublicKey::from_slice(context, &pdata));
 		// no way to create SecretKey from raw byte array.
 		let sec: &key::SecretKey = unsafe { ::std::mem::transmute(secret) };
-		let shared = ecdh::SharedSecret::new_raw(context, &publ, &sec);
+		let shared = ecdh::SharedSecret::new_raw(context, &publ, sec);
 
 		let mut s = crypto::Secret::new();
 		s.copy_from_slice(&shared[0..32]);

util/src/error.rs

@@ -82,7 +82,7 @@ impl fmt::Display for UtilError {
 			UtilError::BaseData(ref err) => f.write_fmt(format_args!("{}", err)),
 			UtilError::Network(ref err) => f.write_fmt(format_args!("{}", err)),
 			UtilError::Decoder(ref err) => f.write_fmt(format_args!("{}", err)),
-			UtilError::SimpleString(ref msg) => f.write_str(&msg),
+			UtilError::SimpleString(ref msg) => f.write_str(msg),
 			UtilError::BadSize => f.write_str("Bad input size."),
 			UtilError::Snappy(ref err) => f.write_fmt(format_args!("{}", err)),
 		}

util/src/journaldb/earlymergedb.rs

@@ -131,7 +131,7 @@ impl EarlyMergeDB {
 			// this is the first entry for this node in the journal.
 			if backing.get(h).expect("Low-level database error. Some issue with your hard disk?").is_some() {
 				// already in the backing DB. start counting, and remember it was already in.
-				Self::set_already_in(batch, &h);
+				Self::set_already_in(batch, h);
 				refs.insert(h.clone(), RefInfo{queue_refs: 1, in_archive: true});
 				if trace {
 					trace!(target: "jdb.fine", "    insert({}): New to queue, in DB: Recording and inserting into queue", h);

util/src/journaldb/overlayrecentdb.rs

@@ -193,7 +193,7 @@ impl OverlayRecentDB {
 	#[inline]
 	fn to_short_key(key: &H256) -> H256 {
 		let mut k = H256::new();
-		&mut k[0..DB_PREFIX_LEN].copy_from_slice(&key[0..DB_PREFIX_LEN]);
+		k[0..DB_PREFIX_LEN].copy_from_slice(&key[0..DB_PREFIX_LEN]);
 		k
 	}
 }

util/src/lib.rs

@@ -19,20 +19,16 @@
 #![cfg_attr(feature="dev", plugin(clippy))]
 
 // Clippy settings
-// TODO [todr] not really sure
+// Most of the time much more readable
 #![cfg_attr(feature="dev", allow(needless_range_loop))]
 // Shorter than if-else
 #![cfg_attr(feature="dev", allow(match_bool))]
 // We use that to be more explicit about handled cases
 #![cfg_attr(feature="dev", allow(match_same_arms))]
-// Keeps consistency (all lines with `.clone()`) and helpful when changing ref to non-ref.
+// Keeps consistency (all lines with `.clone()`).
 #![cfg_attr(feature="dev", allow(clone_on_copy))]
-// In most cases it expresses function flow better
-#![cfg_attr(feature="dev", allow(if_not_else))]
 // TODO [todr] a lot of warnings to be fixed
-#![cfg_attr(feature="dev", allow(needless_borrow))]
 #![cfg_attr(feature="dev", allow(assign_op_pattern))]
-#![cfg_attr(feature="dev", allow(unnecessary_operation))]
 
 
 //! Ethcore-util library

util/src/network/connection.rs

@@ -355,7 +355,7 @@ impl EncryptedConnection {
 		self.encoder.encrypt(&mut RefReadBuffer::new(&header), &mut RefWriteBuffer::new(&mut packet), false).expect("Invalid length or padding");
 		EncryptedConnection::update_mac(&mut self.egress_mac, &mut self.mac_encoder,  &packet[0..16]);
 		self.egress_mac.clone().finalize(&mut packet[16..32]);
-		self.encoder.encrypt(&mut RefReadBuffer::new(&payload), &mut RefWriteBuffer::new(&mut packet[32..(32 + len)]), padding == 0).expect("Invalid length or padding");
+		self.encoder.encrypt(&mut RefReadBuffer::new(payload), &mut RefWriteBuffer::new(&mut packet[32..(32 + len)]), padding == 0).expect("Invalid length or padding");
 		if padding != 0 {
 			let pad = [0u8; 16];
 			self.encoder.encrypt(&mut RefReadBuffer::new(&pad[0..padding]), &mut RefWriteBuffer::new(&mut packet[(32 + len)..(32 + len + padding)]), true).expect("Invalid length or padding");

util/src/network/discovery.rs

@@ -167,7 +167,7 @@ impl Discovery {
 	}
 
 	fn clear_ping(&mut self, id: &NodeId) {
-		let mut bucket = self.node_buckets.get_mut(Discovery::distance(&self.id, &id) as usize).unwrap();
+		let mut bucket = self.node_buckets.get_mut(Discovery::distance(&self.id, id) as usize).unwrap();
 		if let Some(node) = bucket.nodes.iter_mut().find(|n| &n.address.id == id) {
 			node.timeout = None;
 		}
@@ -438,7 +438,7 @@ impl Discovery {
 		}
 		let mut packets = Discovery::prepare_neighbours_packets(&nearest);
 		for p in packets.drain(..) {
-			self.send_packet(PACKET_NEIGHBOURS, &from, &p);
+			self.send_packet(PACKET_NEIGHBOURS, from, &p);
 		}
 		trace!(target: "discovery", "Sent {} Neighbours to {:?}", nearest.len(), &from);
 		Ok(None)

util/src/network/host.rs

@@ -355,11 +355,11 @@ impl Host {
 		let keys = if let Some(ref secret) = config.use_secret {
 			KeyPair::from_secret(secret.clone()).unwrap()
 		} else {
-			config.config_path.clone().and_then(|ref p| load_key(&Path::new(&p)))
+			config.config_path.clone().and_then(|ref p| load_key(Path::new(&p)))
 				.map_or_else(|| {
 				let key = KeyPair::create().unwrap();
 				if let Some(path) = config.config_path.clone() {
-					save_key(&Path::new(&path), &key.secret());
+					save_key(Path::new(&path), key.secret());
 				}
 				key
 			},
@@ -1099,7 +1099,7 @@ fn save_key(path: &Path, key: &Secret) {
 			return;
 		}
 	};
-	if let Err(e) = restrict_permissions_owner(&path) {
+	if let Err(e) = restrict_permissions_owner(path) {
 		warn!(target: "network", "Failed to modify permissions of the file (chmod: {})", e);
 	}
 	if let Err(e) = file.write(&key.hex().into_bytes()) {

util/src/network/session.rs

@@ -128,7 +128,7 @@ impl Session {
 		nonce: &H256, stats: Arc<NetworkStats>, host: &HostInfo) -> Result<Session, UtilError>
 		where Message: Send + Clone {
 		let originated = id.is_some();
-		let mut handshake = Handshake::new(token, id, socket, &nonce, stats).expect("Can't create handshake");
+		let mut handshake = Handshake::new(token, id, socket, nonce, stats).expect("Can't create handshake");
 		try!(handshake.start(io, host, originated));
 		Ok(Session {
 			state: State::Handshake(handshake),

util/src/overlaydb.rs

@@ -168,7 +168,7 @@ impl OverlayDB {
 	pub fn revert(&mut self) { self.overlay.clear(); }
 
 	/// Get the number of references that would be committed.
-	pub fn commit_refs(&self, key: &H256) -> i32 { self.overlay.raw(&key).map_or(0, |&(_, refs)| refs) }
+	pub fn commit_refs(&self, key: &H256) -> i32 { self.overlay.raw(key).map_or(0, |&(_, refs)| refs) }
 
 	/// Get the refs and value of the given key.
 	fn payload(&self, key: &H256) -> Option<(Bytes, u32)> {

util/src/trie/standardmap.rs

@@ -106,7 +106,7 @@ impl StandardMap {
 				Alphabet::All => Self::random_bytes(self.min_key, self.journal_key, seed),
 				Alphabet::Low => Self::random_word(low, self.min_key, self.journal_key, seed),
 				Alphabet::Mid => Self::random_word(mid, self.min_key, self.journal_key, seed),
-				Alphabet::Custom(ref a) => Self::random_word(&a, self.min_key, self.journal_key, seed),
+				Alphabet::Custom(ref a) => Self::random_word(a, self.min_key, self.journal_key, seed),
 			};
 			let v = match self.value_mode {
 				ValueMode::Mirror => k.clone(),

util/src/trie/triedb.rs

@@ -132,7 +132,7 @@ impl<'db> TrieDB<'db> {
 
 	/// Get the data of the root node.
 	fn root_data(&self) -> &[u8] {
-		self.db.get(&self.root).expect("Trie root not found!")
+		self.db.get(self.root).expect("Trie root not found!")
 	}
 
 	/// Get the root node as a `Node`.
@@ -184,7 +184,7 @@ impl<'db> TrieDB<'db> {
 	/// Return optional data for a key given as a `NibbleSlice`. Returns `None` if no data exists.
 	fn do_lookup<'a, 'key>(&'a self, key: &NibbleSlice<'key>) -> Option<&'a [u8]> where 'a: 'key {
 		let root_rlp = self.root_data();
-		self.get_from_node(&root_rlp, key)
+		self.get_from_node(root_rlp, key)
 	}
 
 	/// Recursible function to retrieve the value given a `node` and a partial `key`. `None` if no
@@ -340,7 +340,7 @@ impl<'db> Trie for TrieDB<'db> {
 		Box::new(TrieDB::iter(self))
 	}
 
-	fn root(&self) -> &H256 { &self.root }
+	fn root(&self) -> &H256 { self.root }
 
 	fn contains(&self, key: &[u8]) -> bool {
 		self.get(key).is_some()
@@ -354,7 +354,7 @@ impl<'db> Trie for TrieDB<'db> {
 impl<'db> fmt::Debug for TrieDB<'db> {
 	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
 		try!(writeln!(f, "c={:?} [", self.hash_count));
-		let root_rlp = self.db.get(&self.root).expect("Trie root not found!");
+		let root_rlp = self.db.get(self.root).expect("Trie root not found!");
 		try!(self.fmt_all(Node::decoded(root_rlp), f, 0));
 		writeln!(f, "]")
 	}
@@ -373,7 +373,7 @@ fn iterator() {
 	{
 		let mut t = TrieDBMut::new(&mut memdb, &mut root);
 		for x in &d {
-			t.insert(&x, &x);
+			t.insert(x, x);
 		}
 	}
 	assert_eq!(d.iter().map(|i|i.to_vec()).collect::<Vec<_>>(), TrieDB::new(&memdb, &root).unwrap().iter().map(|x|x.0).collect::<Vec<_>>());

util/src/trie/triedbmut.rs

@@ -401,7 +401,7 @@ impl<'a> TrieDBMut<'a> {
 
 	/// Return optional data for a key given as a `NibbleSlice`. Returns `None` if no data exists.
 	fn do_db_lookup<'x, 'key>(&'x self, hash: &H256, key: NibbleSlice<'key>) -> Option<&'x [u8]> where 'x: 'key {
-		self.db.get(hash).and_then(|node_rlp| self.get_from_db_node(&node_rlp, key))
+		self.db.get(hash).and_then(|node_rlp| self.get_from_db_node(node_rlp, key))
 	}
 
 	/// Recursible function to retrieve the value given a `node` and a partial `key`. `None` if no
@@ -868,7 +868,7 @@ impl<'a> TrieDBMut<'a> {
 impl<'a> TrieMut for TrieDBMut<'a> {
 	fn root(&mut self) -> &H256 {
 		self.commit();
-		&self.root
+		self.root
 	}
 
 	fn is_empty(&self) -> bool {
@@ -938,7 +938,7 @@ mod tests {
 		for i in 0..v.len() {
 			let key: &[u8]= &v[i].0;
 			let val: &[u8] = &v[i].1;
-			t.insert(&key, &val);
+			t.insert(key, val);
 		}
 		t
 	}
@@ -946,7 +946,7 @@ mod tests {
 	fn unpopulate_trie<'db>(t: &mut TrieDBMut<'db>, v: &[(Vec<u8>, Vec<u8>)]) {
 		for i in v {
 			let key: &[u8]= &i.0;
-			t.remove(&key);
+			t.remove(key);
 		}
 	}
 

util/src/triehash.rs

@@ -213,7 +213,7 @@ fn hash256rlp(input: &[(Vec<u8>, Vec<u8>)], pre_len: usize, stream: &mut RlpStre
 		.skip(1)
 		// get minimum number of shared nibbles between first and each successive
 		.fold(key.len(), | acc, &(ref k, _) | {
-			cmp::min(key.shared_prefix_len(&k), acc)
+			cmp::min(key.shared_prefix_len(k), acc)
 		});
 
 	// if shared prefix is higher than current prefix append its