Fix warnings: dyn

accounts/ethstore/cli/src/main.rs

@@ -164,7 +164,7 @@ fn main() {
     }
 }
 
-fn key_dir(location: &str, password: Option<Password>) -> Result<Box<KeyDirectory>, Error> {
+fn key_dir(location: &str, password: Option<Password>) -> Result<Box<dyn KeyDirectory>, Error> {
     let dir: RootDiskDirectory = match location {
         "geth" => RootDiskDirectory::create(dir::geth(false))?,
         "geth-test" => RootDiskDirectory::create(dir::geth(true))?,

accounts/ethstore/src/accounts_dir/disk.rs

@@ -335,7 +335,7 @@ where
         Some(&self.path)
     }
 
-    fn as_vault_provider(&self) -> Option<&VaultKeyDirectoryProvider> {
+    fn as_vault_provider(&self) -> Option<&dyn VaultKeyDirectoryProvider> {
         Some(self)
     }
 
@@ -348,12 +348,12 @@ impl<T> VaultKeyDirectoryProvider for DiskDirectory<T>
 where
     T: KeyFileManager,
 {
-    fn create(&self, name: &str, key: VaultKey) -> Result<Box<VaultKeyDirectory>, Error> {
+    fn create(&self, name: &str, key: VaultKey) -> Result<Box<dyn VaultKeyDirectory>, Error> {
         let vault_dir = VaultDiskDirectory::create(&self.path, name, key)?;
         Ok(Box::new(vault_dir))
     }
 
-    fn open(&self, name: &str, key: VaultKey) -> Result<Box<VaultKeyDirectory>, Error> {
+    fn open(&self, name: &str, key: VaultKey) -> Result<Box<dyn VaultKeyDirectory>, Error> {
         let vault_dir = VaultDiskDirectory::at(&self.path, name, key)?;
         Ok(Box::new(vault_dir))
     }

accounts/ethstore/src/accounts_dir/mod.rs

@@ -60,7 +60,7 @@ pub trait KeyDirectory: Send + Sync {
         None
     }
     /// Return vault provider, if available
-    fn as_vault_provider(&self) -> Option<&VaultKeyDirectoryProvider> {
+    fn as_vault_provider(&self) -> Option<&dyn VaultKeyDirectoryProvider> {
         None
     }
     /// Unique representation of directory account collection
@@ -70,9 +70,9 @@ pub trait KeyDirectory: Send + Sync {
 /// Vaults provider
 pub trait VaultKeyDirectoryProvider {
     /// Create new vault with given key
-    fn create(&self, name: &str, key: VaultKey) -> Result<Box<VaultKeyDirectory>, Error>;
+    fn create(&self, name: &str, key: VaultKey) -> Result<Box<dyn VaultKeyDirectory>, Error>;
     /// Open existing vault with given key
-    fn open(&self, name: &str, key: VaultKey) -> Result<Box<VaultKeyDirectory>, Error>;
+    fn open(&self, name: &str, key: VaultKey) -> Result<Box<dyn VaultKeyDirectory>, Error>;
     /// List all vaults
     fn list_vaults(&self) -> Result<Vec<String>, Error>;
     /// Get vault meta
@@ -82,7 +82,7 @@ pub trait VaultKeyDirectoryProvider {
 /// Vault directory
 pub trait VaultKeyDirectory: KeyDirectory {
     /// Cast to `KeyDirectory`
-    fn as_key_directory(&self) -> &KeyDirectory;
+    fn as_key_directory(&self) -> &dyn KeyDirectory;
     /// Vault name
     fn name(&self) -> &str;
     /// Get vault key

accounts/ethstore/src/accounts_dir/vault.rs

@@ -146,7 +146,7 @@ impl VaultDiskDirectory {
 }
 
 impl VaultKeyDirectory for VaultDiskDirectory {
-    fn as_key_directory(&self) -> &KeyDirectory {
+    fn as_key_directory(&self) -> &dyn KeyDirectory {
         self
     }
 

accounts/ethstore/src/ethstore.rs

@@ -52,13 +52,13 @@ pub struct EthStore {
 
 impl EthStore {
     /// Open a new accounts store with given key directory backend.
-    pub fn open(directory: Box<KeyDirectory>) -> Result<Self, Error> {
+    pub fn open(directory: Box<dyn KeyDirectory>) -> Result<Self, Error> {
         Self::open_with_iterations(directory, *KEY_ITERATIONS)
     }
 
     /// Open a new account store with given key directory backend and custom number of iterations.
     pub fn open_with_iterations(
-        directory: Box<KeyDirectory>,
+        directory: Box<dyn KeyDirectory>,
         iterations: NonZeroU32,
     ) -> Result<Self, Error> {
         Ok(EthStore {
@@ -278,7 +278,7 @@ impl SecretStore for EthStore {
 
     fn copy_account(
         &self,
-        new_store: &SimpleSecretStore,
+        new_store: &dyn SimpleSecretStore,
         new_vault: SecretVaultRef,
         account: &StoreAccountRef,
         password: &Password,
@@ -367,11 +367,11 @@ impl SecretStore for EthStore {
 
 /// Similar to `EthStore` but may store many accounts (with different passwords) for the same `Address`
 pub struct EthMultiStore {
-    dir: Box<KeyDirectory>,
+    dir: Box<dyn KeyDirectory>,
     iterations: NonZeroU32,
     // order lock: cache, then vaults
     cache: RwLock<BTreeMap<StoreAccountRef, Vec<SafeAccount>>>,
-    vaults: Mutex<HashMap<String, Box<VaultKeyDirectory>>>,
+    vaults: Mutex<HashMap<String, Box<dyn VaultKeyDirectory>>>,
     timestamp: Mutex<Timestamp>,
 }
 
@@ -383,13 +383,13 @@ struct Timestamp {
 
 impl EthMultiStore {
     /// Open new multi-accounts store with given key directory backend.
-    pub fn open(directory: Box<KeyDirectory>) -> Result<Self, Error> {
+    pub fn open(directory: Box<dyn KeyDirectory>) -> Result<Self, Error> {
         Self::open_with_iterations(directory, *KEY_ITERATIONS)
     }
 
     /// Open new multi-accounts store with given key directory backend and custom number of iterations for new keys.
     pub fn open_with_iterations(
-        directory: Box<KeyDirectory>,
+        directory: Box<dyn KeyDirectory>,
         iterations: NonZeroU32,
     ) -> Result<Self, Error> {
         let store = EthMultiStore {
@@ -953,7 +953,7 @@ mod tests {
     }
 
     struct RootDiskDirectoryGuard {
-        pub key_dir: Option<Box<KeyDirectory>>,
+        pub key_dir: Option<Box<dyn KeyDirectory>>,
         _path: TempDir,
     }
 

accounts/ethstore/src/import.rs

@@ -22,7 +22,7 @@ use ethkey::Address;
 use Error;
 
 /// Import an account from a file.
-pub fn import_account(path: &Path, dst: &KeyDirectory) -> Result<Address, Error> {
+pub fn import_account(path: &Path, dst: &dyn KeyDirectory) -> Result<Address, Error> {
     let key_manager = DiskKeyFileManager::default();
     let existing_accounts = dst
         .load()?
@@ -45,7 +45,10 @@ pub fn import_account(path: &Path, dst: &KeyDirectory) -> Result<Address, Error>
 }
 
 /// Import all accounts from one directory to the other.
-pub fn import_accounts(src: &KeyDirectory, dst: &KeyDirectory) -> Result<Vec<Address>, Error> {
+pub fn import_accounts(
+    src: &dyn KeyDirectory,
+    dst: &dyn KeyDirectory,
+) -> Result<Vec<Address>, Error> {
     let accounts = src.load()?;
     let existing_accounts = dst
         .load()?
@@ -74,7 +77,7 @@ pub fn read_geth_accounts(testnet: bool) -> Vec<Address> {
 
 /// Import specific `desired` accounts from the Geth keystore into `dst`.
 pub fn import_geth_accounts(
-    dst: &KeyDirectory,
+    dst: &dyn KeyDirectory,
     desired: HashSet<Address>,
     testnet: bool,
 ) -> Result<Vec<Address>, Error> {

accounts/ethstore/src/secret_store.rs

@@ -195,7 +195,7 @@ pub trait SecretStore: SimpleSecretStore {
     /// Copies account between stores and vaults.
     fn copy_account(
         &self,
-        new_store: &SimpleSecretStore,
+        new_store: &dyn SimpleSecretStore,
         new_vault: SecretVaultRef,
         account: &StoreAccountRef,
         password: &Password,

accounts/hw/src/trezor.rs

@@ -231,7 +231,7 @@ impl Manager {
         &self,
         device: &hidapi::HidDevice,
         msg_type: MessageType,
-        msg: &Message,
+        msg: &dyn Message,
     ) -> Result<usize, Error> {
         let msg_id = msg_type as u16;
         let mut message = msg.write_to_bytes()?;

accounts/src/lib.rs

@@ -77,7 +77,7 @@ pub struct AccountProvider {
     /// Address book.
     address_book: RwLock<AddressBook>,
     /// Accounts on disk
-    sstore: Box<SecretStore>,
+    sstore: Box<dyn SecretStore>,
     /// Accounts unlocked with rolling tokens
     transient_sstore: EthMultiStore,
     /// Accounts in hardware wallets.
@@ -96,7 +96,7 @@ fn transient_sstore() -> EthMultiStore {
 
 impl AccountProvider {
     /// Creates new account provider.
-    pub fn new(sstore: Box<SecretStore>, settings: AccountProviderSettings) -> Self {
+    pub fn new(sstore: Box<dyn SecretStore>, settings: AccountProviderSettings) -> Self {
         let mut hardware_store = None;
 
         if settings.enable_hardware_wallets {

cli-signer/rpc-client/src/lib.rs

@@ -36,7 +36,7 @@ extern crate log;
 extern crate matches;
 
 /// Boxed future response.
-pub type BoxFuture<T, E> = Box<futures::Future<Item = T, Error = E> + Send>;
+pub type BoxFuture<T, E> = Box<dyn futures::Future<Item = T, Error = E> + Send>;
 
 #[cfg(test)]
 mod tests {

ethcore/blockchain/src/blockchain.rs

@@ -68,7 +68,7 @@ use crate::{
 /// Database backing `BlockChain`.
 pub trait BlockChainDB: Send + Sync {
     /// Generic key value store.
-    fn key_value(&self) -> &Arc<KeyValueDB>;
+    fn key_value(&self) -> &Arc<dyn KeyValueDB>;
 
     /// Header blooms database.
     fn blooms(&self) -> &blooms_db::Database;
@@ -96,7 +96,7 @@ pub trait BlockChainDB: Send + Sync {
 /// predefined config.
 pub trait BlockChainDBHandler: Send + Sync {
     /// Open the predefined key-value database.
-    fn open(&self, path: &Path) -> io::Result<Arc<BlockChainDB>>;
+    fn open(&self, path: &Path) -> io::Result<Arc<dyn BlockChainDB>>;
 }
 
 /// Interface for querying blocks by hash and by number.
@@ -262,7 +262,7 @@ pub struct BlockChain {
     transaction_addresses: RwLock<HashMap<H256, TransactionAddress>>,
     block_receipts: RwLock<HashMap<H256, BlockReceipts>>,
 
-    db: Arc<BlockChainDB>,
+    db: Arc<dyn BlockChainDB>,
 
     cache_man: Mutex<CacheManager<CacheId>>,
 
@@ -576,7 +576,7 @@ impl<'a> Iterator for AncestryWithMetadataIter<'a> {
 /// Returns epoch transitions.
 pub struct EpochTransitionIter<'a> {
     chain: &'a BlockChain,
-    prefix_iter: Box<Iterator<Item = (Box<[u8]>, Box<[u8]>)> + 'a>,
+    prefix_iter: Box<dyn Iterator<Item = (Box<[u8]>, Box<[u8]>)> + 'a>,
 }
 
 impl<'a> Iterator for EpochTransitionIter<'a> {
@@ -621,7 +621,7 @@ impl<'a> Iterator for EpochTransitionIter<'a> {
 
 impl BlockChain {
     /// Create new instance of blockchain from given Genesis.
-    pub fn new(config: Config, genesis: &[u8], db: Arc<BlockChainDB>) -> BlockChain {
+    pub fn new(config: Config, genesis: &[u8], db: Arc<dyn BlockChainDB>) -> BlockChain {
         // 400 is the average size of the key
         let cache_man = CacheManager::new(config.pref_cache_size, config.max_cache_size, 400);
 
@@ -1934,11 +1934,11 @@ mod tests {
         _trace_blooms_dir: TempDir,
         blooms: blooms_db::Database,
         trace_blooms: blooms_db::Database,
-        key_value: Arc<KeyValueDB>,
+        key_value: Arc<dyn KeyValueDB>,
     }
 
     impl BlockChainDB for TestBlockChainDB {
-        fn key_value(&self) -> &Arc<KeyValueDB> {
+        fn key_value(&self) -> &Arc<dyn KeyValueDB> {
             &self.key_value
         }
 
@@ -1952,7 +1952,7 @@ mod tests {
     }
 
     /// Creates new test instance of `BlockChainDB`
-    pub fn new_db() -> Arc<BlockChainDB> {
+    pub fn new_db() -> Arc<dyn BlockChainDB> {
         let blooms_dir = TempDir::new("").unwrap();
         let trace_blooms_dir = TempDir::new("").unwrap();
 
@@ -1967,12 +1967,12 @@ mod tests {
         Arc::new(db)
     }
 
-    fn new_chain(genesis: encoded::Block, db: Arc<BlockChainDB>) -> BlockChain {
+    fn new_chain(genesis: encoded::Block, db: Arc<dyn BlockChainDB>) -> BlockChain {
         BlockChain::new(Config::default(), genesis.raw(), db)
     }
 
     fn insert_block(
-        db: &Arc<BlockChainDB>,
+        db: &Arc<dyn BlockChainDB>,
         bc: &BlockChain,
         block: encoded::Block,
         receipts: Vec<Receipt>,
@@ -1981,7 +1981,7 @@ mod tests {
     }
 
     fn insert_block_commit(
-        db: &Arc<BlockChainDB>,
+        db: &Arc<dyn BlockChainDB>,
         bc: &BlockChain,
         block: encoded::Block,
         receipts: Vec<Receipt>,

ethcore/db/src/db.rs

@@ -92,13 +92,13 @@ pub trait Key<T> {
 /// Should be used to write value into database.
 pub trait Writable {
     /// Writes the value into the database.
-    fn write<T, R>(&mut self, col: Option<u32>, key: &Key<T, Target = R>, value: &T)
+    fn write<T, R>(&mut self, col: Option<u32>, key: &dyn Key<T, Target = R>, value: &T)
     where
         T: rlp::Encodable,
         R: Deref<Target = [u8]>;
 
     /// Deletes key from the databse.
-    fn delete<T, R>(&mut self, col: Option<u32>, key: &Key<T, Target = R>)
+    fn delete<T, R>(&mut self, col: Option<u32>, key: &dyn Key<T, Target = R>)
     where
         T: rlp::Encodable,
         R: Deref<Target = [u8]>;
@@ -107,7 +107,7 @@ pub trait Writable {
     fn write_with_cache<K, T, R>(
         &mut self,
         col: Option<u32>,
-        cache: &mut Cache<K, T>,
+        cache: &mut dyn Cache<K, T>,
         key: K,
         value: T,
         policy: CacheUpdatePolicy,
@@ -131,7 +131,7 @@ pub trait Writable {
     fn extend_with_cache<K, T, R>(
         &mut self,
         col: Option<u32>,
-        cache: &mut Cache<K, T>,
+        cache: &mut dyn Cache<K, T>,
         values: HashMap<K, T>,
         policy: CacheUpdatePolicy,
     ) where
@@ -159,7 +159,7 @@ pub trait Writable {
     fn extend_with_option_cache<K, T, R>(
         &mut self,
         col: Option<u32>,
-        cache: &mut Cache<K, Option<T>>,
+        cache: &mut dyn Cache<K, Option<T>>,
         values: HashMap<K, Option<T>>,
         policy: CacheUpdatePolicy,
     ) where
@@ -193,7 +193,7 @@ pub trait Writable {
 /// Should be used to read values from database.
 pub trait Readable {
     /// Returns value for given key.
-    fn read<T, R>(&self, col: Option<u32>, key: &Key<T, Target = R>) -> Option<T>
+    fn read<T, R>(&self, col: Option<u32>, key: &dyn Key<T, Target = R>) -> Option<T>
     where
         T: rlp::Decodable,
         R: Deref<Target = [u8]>;
@@ -243,7 +243,7 @@ pub trait Readable {
     }
 
     /// Returns true if given value exists.
-    fn exists<T, R>(&self, col: Option<u32>, key: &Key<T, Target = R>) -> bool
+    fn exists<T, R>(&self, col: Option<u32>, key: &dyn Key<T, Target = R>) -> bool
     where
         R: Deref<Target = [u8]>;
 
@@ -266,7 +266,7 @@ pub trait Readable {
 }
 
 impl Writable for DBTransaction {
-    fn write<T, R>(&mut self, col: Option<u32>, key: &Key<T, Target = R>, value: &T)
+    fn write<T, R>(&mut self, col: Option<u32>, key: &dyn Key<T, Target = R>, value: &T)
     where
         T: rlp::Encodable,
         R: Deref<Target = [u8]>,
@@ -274,7 +274,7 @@ impl Writable for DBTransaction {
         self.put(col, &key.key(), &rlp::encode(value));
     }
 
-    fn delete<T, R>(&mut self, col: Option<u32>, key: &Key<T, Target = R>)
+    fn delete<T, R>(&mut self, col: Option<u32>, key: &dyn Key<T, Target = R>)
     where
         T: rlp::Encodable,
         R: Deref<Target = [u8]>,
@@ -284,7 +284,7 @@ impl Writable for DBTransaction {
 }
 
 impl<KVDB: KeyValueDB + ?Sized> Readable for KVDB {
-    fn read<T, R>(&self, col: Option<u32>, key: &Key<T, Target = R>) -> Option<T>
+    fn read<T, R>(&self, col: Option<u32>, key: &dyn Key<T, Target = R>) -> Option<T>
     where
         T: rlp::Decodable,
         R: Deref<Target = [u8]>,
@@ -294,7 +294,7 @@ impl<KVDB: KeyValueDB + ?Sized> Readable for KVDB {
             .map(|v| rlp::decode(&v).expect("decode db value failed"))
     }
 
-    fn exists<T, R>(&self, col: Option<u32>, key: &Key<T, Target = R>) -> bool
+    fn exists<T, R>(&self, col: Option<u32>, key: &dyn Key<T, Target = R>) -> bool
     where
         R: Deref<Target = [u8]>,
     {

ethcore/evm/src/factory.rs

@@ -31,7 +31,7 @@ pub struct Factory {
 impl Factory {
     /// Create fresh instance of VM
     /// Might choose implementation depending on supplied gas.
-    pub fn create(&self, params: ActionParams, schedule: &Schedule, depth: usize) -> Box<Exec> {
+    pub fn create(&self, params: ActionParams, schedule: &Schedule, depth: usize) -> Box<dyn Exec> {
         match self.evm {
             VMType::Interpreter => {
                 if Self::can_fit_in_usize(&params.gas) {

ethcore/evm/src/interpreter/gasometer.rs

@@ -112,10 +112,10 @@ impl<Gas: evm::CostType> Gasometer<Gas> {
     /// it will be the amount of gas that the current context provides to the child context.
     pub fn requirements(
         &mut self,
-        ext: &vm::Ext,
+        ext: &dyn vm::Ext,
         instruction: Instruction,
         info: &InstructionInfo,
-        stack: &Stack<U256>,
+        stack: &dyn Stack<U256>,
         current_mem_size: usize,
     ) -> vm::Result<InstructionRequirements<Gas>> {
         let schedule = ext.schedule();
@@ -427,7 +427,7 @@ fn calculate_eip1283_sstore_gas<Gas: evm::CostType>(
 }
 
 pub fn handle_eip1283_sstore_clears_refund(
-    ext: &mut vm::Ext,
+    ext: &mut dyn vm::Ext,
     original: &U256,
     current: &U256,
     new: &U256,

ethcore/evm/src/interpreter/informant.rs

@@ -96,7 +96,7 @@ mod inner {
             instruction: Instruction,
             info: &InstructionInfo,
             current_gas: &Cost,
-            stack: &Stack<U256>,
+            stack: &dyn Stack<U256>,
         ) {
             let time = self.last_instruction.elapsed();
             self.last_instruction = Instant::now();

ethcore/evm/src/interpreter/memory.rs

@@ -136,7 +136,7 @@ mod tests {
     #[test]
     fn test_memory_read_and_write() {
         // given
-        let mem: &mut Memory = &mut vec![];
+        let mem: &mut dyn Memory = &mut vec![];
         mem.resize(0x80 + 32);
 
         // when
@@ -149,7 +149,7 @@ mod tests {
     #[test]
     fn test_memory_read_and_write_byte() {
         // given
-        let mem: &mut Memory = &mut vec![];
+        let mem: &mut dyn Memory = &mut vec![];
         mem.resize(32);
 
         // when
@@ -163,7 +163,7 @@ mod tests {
 
     #[test]
     fn test_memory_read_slice_and_write_slice() {
-        let mem: &mut Memory = &mut vec![];
+        let mem: &mut dyn Memory = &mut vec![];
         mem.resize(32);
 
         {

ethcore/evm/src/interpreter/mod.rs

@@ -192,7 +192,7 @@ pub struct Interpreter<Cost: CostType> {
 }
 
 impl<Cost: 'static + CostType> vm::Exec for Interpreter<Cost> {
-    fn exec(mut self: Box<Self>, ext: &mut vm::Ext) -> vm::ExecTrapResult<GasLeft> {
+    fn exec(mut self: Box<Self>, ext: &mut dyn vm::Ext) -> vm::ExecTrapResult<GasLeft> {
         loop {
             let result = self.step(ext);
             match result {
@@ -213,7 +213,7 @@ impl<Cost: 'static + CostType> vm::Exec for Interpreter<Cost> {
 }
 
 impl<Cost: 'static + CostType> vm::ResumeCall for Interpreter<Cost> {
-    fn resume_call(mut self: Box<Self>, result: MessageCallResult) -> Box<vm::Exec> {
+    fn resume_call(mut self: Box<Self>, result: MessageCallResult) -> Box<dyn vm::Exec> {
         {
             let this = &mut *self;
             let (out_off, out_size) = this.resume_output_range.take().expect("Box<ResumeCall> is obtained from a call opcode; resume_output_range is always set after those opcodes are executed; qed");
@@ -254,7 +254,7 @@ impl<Cost: 'static + CostType> vm::ResumeCall for Interpreter<Cost> {
 }
 
 impl<Cost: 'static + CostType> vm::ResumeCreate for Interpreter<Cost> {
-    fn resume_create(mut self: Box<Self>, result: ContractCreateResult) -> Box<vm::Exec> {
+    fn resume_create(mut self: Box<Self>, result: ContractCreateResult) -> Box<dyn vm::Exec> {
         match result {
             ContractCreateResult::Created(address, gas_left) => {
                 self.stack.push(address_to_u256(address));
@@ -318,7 +318,7 @@ impl<Cost: CostType> Interpreter<Cost> {
 
     /// Execute a single step on the VM.
     #[inline(always)]
-    pub fn step(&mut self, ext: &mut vm::Ext) -> InterpreterResult {
+    pub fn step(&mut self, ext: &mut dyn vm::Ext) -> InterpreterResult {
         if self.done {
             return InterpreterResult::Stopped;
         }
@@ -531,7 +531,7 @@ impl<Cost: CostType> Interpreter<Cost> {
 
     fn verify_instruction(
         &self,
-        ext: &vm::Ext,
+        ext: &dyn vm::Ext,
         instruction: Instruction,
         info: &InstructionInfo,
     ) -> vm::Result<()> {
@@ -574,7 +574,7 @@ impl<Cost: CostType> Interpreter<Cost> {
         }
     }
 
-    fn mem_written(instruction: Instruction, stack: &Stack<U256>) -> Option<(usize, usize)> {
+    fn mem_written(instruction: Instruction, stack: &dyn Stack<U256>) -> Option<(usize, usize)> {
         let read = |pos| stack.peek(pos).low_u64() as usize;
         let written = match instruction {
             instructions::MSTORE | instructions::MLOAD => Some((read(0), 32)),
@@ -594,7 +594,7 @@ impl<Cost: CostType> Interpreter<Cost> {
         }
     }
 
-    fn store_written(instruction: Instruction, stack: &Stack<U256>) -> Option<(U256, U256)> {
+    fn store_written(instruction: Instruction, stack: &dyn Stack<U256>) -> Option<(U256, U256)> {
         match instruction {
             instructions::SSTORE => Some((stack.peek(0).clone(), stack.peek(1).clone())),
             _ => None,
@@ -604,7 +604,7 @@ impl<Cost: CostType> Interpreter<Cost> {
     fn exec_instruction(
         &mut self,
         gas: Cost,
-        ext: &mut vm::Ext,
+        ext: &mut dyn vm::Ext,
         instruction: Instruction,
         provided: Option<Cost>,
     ) -> vm::Result<InstructionResult<Cost>> {
@@ -1374,7 +1374,7 @@ impl<Cost: CostType> Interpreter<Cost> {
         Ok(InstructionResult::Ok)
     }
 
-    fn copy_data_to_memory(mem: &mut Vec<u8>, stack: &mut Stack<U256>, source: &[u8]) {
+    fn copy_data_to_memory(mem: &mut Vec<u8>, stack: &mut dyn Stack<U256>, source: &[u8]) {
         let dest_offset = stack.pop_back();
         let source_offset = stack.pop_back();
         let size = stack.pop_back();
@@ -1462,7 +1462,7 @@ mod tests {
     };
     use vmtype::VMType;
 
-    fn interpreter(params: ActionParams, ext: &vm::Ext) -> Box<Exec> {
+    fn interpreter(params: ActionParams, ext: &dyn vm::Ext) -> Box<dyn Exec> {
         Factory::new(VMType::Interpreter, 1).create(params, ext.schedule(), ext.depth())
     }
 

ethcore/light/src/cht.rs

@@ -82,7 +82,7 @@ impl<DB: HashDB<KeccakHasher, DBValue>> CHT<DB> {
         }
 
         let mut recorder = Recorder::with_depth(from_level);
-        let db: &HashDB<_, _> = &self.db;
+        let db: &dyn HashDB<_, _> = &self.db;
         let t = TrieDB::new(&db, &self.root)?;
         t.get_with(&key!(num), &mut recorder)?;
 

ethcore/light/src/client/fetch.rs

@@ -48,8 +48,8 @@ pub trait ChainDataFetcher: Send + Sync + 'static {
     fn epoch_transition(
         &self,
         _hash: H256,
-        _engine: Arc<EthEngine>,
+        _engine: Arc<dyn EthEngine>,
-        _checker: Arc<StateDependentProof<EthereumMachine>>,
+        _checker: Arc<dyn StateDependentProof<EthereumMachine>>,
     ) -> Self::Transition;
 }
 
@@ -79,8 +79,8 @@ impl ChainDataFetcher for Unavailable {
     fn epoch_transition(
         &self,
         _hash: H256,
-        _engine: Arc<EthEngine>,
+        _engine: Arc<dyn EthEngine>,
-        _checker: Arc<StateDependentProof<EthereumMachine>>,
+        _checker: Arc<dyn StateDependentProof<EthereumMachine>>,
     ) -> Self::Transition {
         Err("fetching epoch transition proofs unavailable")
     }

ethcore/light/src/client/header_chain.rs

@@ -202,7 +202,7 @@ pub struct HeaderChain {
     candidates: RwLock<BTreeMap<u64, Entry>>,
     best_block: RwLock<BlockDescriptor>,
     live_epoch_proofs: RwLock<H256FastMap<EpochTransition>>,
-    db: Arc<KeyValueDB>,
+    db: Arc<dyn KeyValueDB>,
     col: Option<u32>,
     cache: Arc<Mutex<Cache>>,
 }
@@ -210,7 +210,7 @@ pub struct HeaderChain {
 impl HeaderChain {
     /// Create a new header chain given this genesis block and database to read from.
     pub fn new(
-        db: Arc<KeyValueDB>,
+        db: Arc<dyn KeyValueDB>,
         col: Option<u32>,
         spec: &Spec,
         cache: Arc<Mutex<Cache>>,
@@ -955,7 +955,7 @@ mod tests {
     use parking_lot::Mutex;
     use std::time::Duration;
 
-    fn make_db() -> Arc<KeyValueDB> {
+    fn make_db() -> Arc<dyn KeyValueDB> {
         Arc::new(kvdb_memorydb::create(0))
     }
 

ethcore/light/src/client/mod.rs

@@ -81,7 +81,7 @@ impl Default for Config {
 /// Trait for interacting with the header chain abstractly.
 pub trait LightChainClient: Send + Sync {
     /// Adds a new `LightChainNotify` listener.
-    fn add_listener(&self, listener: Weak<LightChainNotify>);
+    fn add_listener(&self, listener: Weak<dyn LightChainNotify>);
 
     /// Get chain info.
     fn chain_info(&self) -> BlockChainInfo;
@@ -103,7 +103,10 @@ pub trait LightChainClient: Send + Sync {
     fn score(&self, id: BlockId) -> Option<U256>;
 
     /// Get an iterator over a block and its ancestry.
-    fn ancestry_iter<'a>(&'a self, start: BlockId) -> Box<Iterator<Item = encoded::Header> + 'a>;
+    fn ancestry_iter<'a>(
+        &'a self,
+        start: BlockId,
+    ) -> Box<dyn Iterator<Item = encoded::Header> + 'a>;
 
     /// Get the signing chain ID.
     fn signing_chain_id(&self) -> Option<u64>;
@@ -113,7 +116,7 @@ pub trait LightChainClient: Send + Sync {
     fn env_info(&self, id: BlockId) -> Option<EnvInfo>;
 
     /// Get a handle to the consensus engine.
-    fn engine(&self) -> &Arc<EthEngine>;
+    fn engine(&self) -> &Arc<dyn EthEngine>;
 
     /// Query whether a block is known.
     fn is_known(&self, hash: &H256) -> bool;
@@ -163,23 +166,23 @@ impl<T: LightChainClient> AsLightClient for T {
 /// Light client implementation.
 pub struct Client<T> {
     queue: HeaderQueue,
-    engine: Arc<EthEngine>,
+    engine: Arc<dyn EthEngine>,
     chain: HeaderChain,
     report: RwLock<ClientReport>,
     import_lock: Mutex<()>,
-    db: Arc<KeyValueDB>,
+    db: Arc<dyn KeyValueDB>,
-    listeners: RwLock<Vec<Weak<LightChainNotify>>>,
+    listeners: RwLock<Vec<Weak<dyn LightChainNotify>>>,
     fetcher: T,
     verify_full: bool,
     /// A closure to call when we want to restart the client
-    exit_handler: Mutex<Option<Box<Fn(String) + 'static + Send>>>,
+    exit_handler: Mutex<Option<Box<dyn Fn(String) + 'static + Send>>>,
 }
 
 impl<T: ChainDataFetcher> Client<T> {
     /// Create a new `Client`.
     pub fn new(
         config: Config,
-        db: Arc<KeyValueDB>,
+        db: Arc<dyn KeyValueDB>,
         chain_col: Option<u32>,
         spec: &Spec,
         fetcher: T,
@@ -221,7 +224,7 @@ impl<T: ChainDataFetcher> Client<T> {
     }
 
     /// Adds a new `LightChainNotify` listener.
-    pub fn add_listener(&self, listener: Weak<LightChainNotify>) {
+    pub fn add_listener(&self, listener: Weak<dyn LightChainNotify>) {
         self.listeners.write().push(listener);
     }
 
@@ -398,7 +401,7 @@ impl<T: ChainDataFetcher> Client<T> {
     }
 
     /// Get a handle to the verification engine.
-    pub fn engine(&self) -> &Arc<EthEngine> {
+    pub fn engine(&self) -> &Arc<dyn EthEngine> {
         &self.engine
     }
 
@@ -439,7 +442,7 @@ impl<T: ChainDataFetcher> Client<T> {
         Arc::new(v)
     }
 
-    fn notify<F: Fn(&LightChainNotify)>(&self, f: F) {
+    fn notify<F: Fn(&dyn LightChainNotify)>(&self, f: F) {
         for listener in &*self.listeners.read() {
             if let Some(listener) = listener.upgrade() {
                 f(&*listener)
@@ -567,7 +570,7 @@ impl<T: ChainDataFetcher> Client<T> {
 }
 
 impl<T: ChainDataFetcher> LightChainClient for Client<T> {
-    fn add_listener(&self, listener: Weak<LightChainNotify>) {
+    fn add_listener(&self, listener: Weak<dyn LightChainNotify>) {
         Client::add_listener(self, listener)
     }
 
@@ -595,7 +598,10 @@ impl<T: ChainDataFetcher> LightChainClient for Client<T> {
         Client::score(self, id)
     }
 
-    fn ancestry_iter<'a>(&'a self, start: BlockId) -> Box<Iterator<Item = encoded::Header> + 'a> {
+    fn ancestry_iter<'a>(
+        &'a self,
+        start: BlockId,
+    ) -> Box<dyn Iterator<Item = encoded::Header> + 'a> {
         Box::new(Client::ancestry_iter(self, start))
     }
 
@@ -607,7 +613,7 @@ impl<T: ChainDataFetcher> LightChainClient for Client<T> {
         Client::env_info(self, id)
     }
 
-    fn engine(&self) -> &Arc<EthEngine> {
+    fn engine(&self) -> &Arc<dyn EthEngine> {
         Client::engine(self)
     }
 
@@ -668,7 +674,7 @@ impl<T: ChainDataFetcher> ::ethcore::client::EngineClient for Client<T> {
             })
     }
 
-    fn as_full_client(&self) -> Option<&::ethcore::client::BlockChainClient> {
+    fn as_full_client(&self) -> Option<&dyn crate::ethcore::client::BlockChainClient> {
         None
     }
 

ethcore/light/src/client/service.rs

@@ -66,7 +66,7 @@ impl<T: ChainDataFetcher> Service<T> {
         config: ClientConfig,
         spec: &Spec,
         fetcher: T,
-        db: Arc<BlockChainDB>,
+        db: Arc<dyn BlockChainDB>,
         cache: Arc<Mutex<Cache>>,
     ) -> Result<Self, Error> {
         let io_service = IoService::<ClientIoMessage>::start().map_err(Error::Io)?;
@@ -89,14 +89,14 @@ impl<T: ChainDataFetcher> Service<T> {
     }
 
     /// Set the actor to be notified on certain chain events
-    pub fn add_notify(&self, notify: Arc<LightChainNotify>) {
+    pub fn add_notify(&self, notify: Arc<dyn LightChainNotify>) {
         self.client.add_listener(Arc::downgrade(&notify));
     }
 
     /// Register an I/O handler on the service.
     pub fn register_handler(
         &self,
-        handler: Arc<IoHandler<ClientIoMessage> + Send>,
+        handler: Arc<dyn IoHandler<ClientIoMessage> + Send>,
     ) -> Result<(), IoError> {
         self.io_service.register_handler(handler)
     }

ethcore/light/src/net/context.rs

@@ -118,13 +118,13 @@ pub trait EventContext: BasicContext {
     fn peer(&self) -> PeerId;
 
     /// Treat the event context as a basic context.
-    fn as_basic(&self) -> &BasicContext;
+    fn as_basic(&self) -> &dyn BasicContext;
 }
 
 /// Basic context.
 pub struct TickCtx<'a> {
     /// Io context to enable dispatch.
-    pub io: &'a IoContext,
+    pub io: &'a dyn IoContext,
     /// Protocol implementation.
     pub proto: &'a LightProtocol,
 }
@@ -155,7 +155,7 @@ impl<'a> BasicContext for TickCtx<'a> {
 /// an io context.
 pub struct Ctx<'a> {
     /// Io context to enable immediate response to events.
-    pub io: &'a IoContext,
+    pub io: &'a dyn IoContext,
     /// Protocol implementation.
     pub proto: &'a LightProtocol,
     /// Relevant peer for event.
@@ -189,7 +189,7 @@ impl<'a> EventContext for Ctx<'a> {
         self.peer
     }
 
-    fn as_basic(&self) -> &BasicContext {
+    fn as_basic(&self) -> &dyn BasicContext {
         &*self
     }
 }

ethcore/light/src/net/load_timer.rs

@@ -89,7 +89,7 @@ pub struct LoadDistribution {
 
 impl LoadDistribution {
     /// Load rolling samples from the given store.
-    pub fn load(store: &SampleStore) -> Self {
+    pub fn load(store: &dyn SampleStore) -> Self {
         let mut samples = store.load();
 
         for kind_samples in samples.values_mut() {
@@ -146,7 +146,7 @@ impl LoadDistribution {
     }
 
     /// End the current time period. Provide a store to
-    pub fn end_period(&self, store: &SampleStore) {
+    pub fn end_period(&self, store: &dyn SampleStore) {
         let active_period = self.active_period.read();
         let mut samples = self.samples.write();
 

ethcore/light/src/net/mod.rs

@@ -242,7 +242,7 @@ pub trait Handler: Send + Sync {
     /// Called when a peer connects.
     fn on_connect(
         &self,
-        _ctx: &EventContext,
+        _ctx: &dyn EventContext,
         _status: &Status,
         _capabilities: &Capabilities,
     ) -> PeerStatus {
@@ -250,19 +250,25 @@ pub trait Handler: Send + Sync {
     }
     /// Called when a peer disconnects, with a list of unfulfilled request IDs as
     /// of yet.
-    fn on_disconnect(&self, _ctx: &EventContext, _unfulfilled: &[ReqId]) {}
+    fn on_disconnect(&self, _ctx: &dyn EventContext, _unfulfilled: &[ReqId]) {}
     /// Called when a peer makes an announcement.
-    fn on_announcement(&self, _ctx: &EventContext, _announcement: &Announcement) {}
+    fn on_announcement(&self, _ctx: &dyn EventContext, _announcement: &Announcement) {}
     /// Called when a peer requests relay of some transactions.
-    fn on_transactions(&self, _ctx: &EventContext, _relay: &[UnverifiedTransaction]) {}
+    fn on_transactions(&self, _ctx: &dyn EventContext, _relay: &[UnverifiedTransaction]) {}
     /// Called when a peer responds to requests.
     /// Responses not guaranteed to contain valid data and are not yet checked against
     /// the requests they correspond to.
-    fn on_responses(&self, _ctx: &EventContext, _req_id: ReqId, _responses: &[Response]) {}
+    fn on_responses(&self, _ctx: &dyn EventContext, _req_id: ReqId, _responses: &[Response]) {}
     /// Called when a peer responds with a transaction proof. Each proof is a vector of state items.
-    fn on_transaction_proof(&self, _ctx: &EventContext, _req_id: ReqId, _state_items: &[DBValue]) {}
+    fn on_transaction_proof(
+        &self,
+        _ctx: &dyn EventContext,
+        _req_id: ReqId,
+        _state_items: &[DBValue],
+    ) {
+    }
     /// Called to "tick" the handler periodically.
-    fn tick(&self, _ctx: &BasicContext) {}
+    fn tick(&self, _ctx: &dyn BasicContext) {}
     /// Called on abort. This signals to handlers that they should clean up
     /// and ignore peers.
     // TODO: coreresponding `on_activate`?
@@ -298,7 +304,7 @@ pub struct Params {
     /// Initial capabilities.
     pub capabilities: Capabilities,
     /// The sample store (`None` if data shouldn't persist between runs).
-    pub sample_store: Option<Box<SampleStore>>,
+    pub sample_store: Option<Box<dyn SampleStore>>,
 }
 
 /// Type alias for convenience.
@@ -403,7 +409,7 @@ impl Statistics {
 //   Locks must be acquired in the order declared, and when holding a read lock
 //   on the peers, only one peer may be held at a time.
 pub struct LightProtocol {
-    provider: Arc<Provider>,
+    provider: Arc<dyn Provider>,
     config: Config,
     genesis_hash: H256,
     network_id: u64,
@@ -412,16 +418,16 @@ pub struct LightProtocol {
     capabilities: RwLock<Capabilities>,
     flow_params: RwLock<Arc<FlowParams>>,
     free_flow_params: Arc<FlowParams>,
-    handlers: Vec<Arc<Handler>>,
+    handlers: Vec<Arc<dyn Handler>>,
     req_id: AtomicUsize,
-    sample_store: Box<SampleStore>,
+    sample_store: Box<dyn SampleStore>,
     load_distribution: LoadDistribution,
     statistics: RwLock<Statistics>,
 }
 
 impl LightProtocol {
     /// Create a new instance of the protocol manager.
-    pub fn new(provider: Arc<Provider>, params: Params) -> Self {
+    pub fn new(provider: Arc<dyn Provider>, params: Params) -> Self {
         debug!(target: "pip", "Initializing light protocol handler");
 
         let genesis_hash = provider.chain_info().genesis_hash;
@@ -494,7 +500,7 @@ impl LightProtocol {
     /// with an event.
     pub fn request_from(
         &self,
-        io: &IoContext,
+        io: &dyn IoContext,
         peer_id: PeerId,
         requests: Requests,
     ) -> Result<ReqId, Error> {
@@ -543,7 +549,7 @@ impl LightProtocol {
 
     /// Make an announcement of new chain head and capabilities to all peers.
     /// The announcement is expected to be valid.
-    pub fn make_announcement(&self, io: &IoContext, mut announcement: Announcement) {
+    pub fn make_announcement(&self, io: &dyn IoContext, mut announcement: Announcement) {
         let mut reorgs_map = HashMap::new();
         let now = Instant::now();
 
@@ -598,7 +604,7 @@ impl LightProtocol {
     /// These are intended to be added when the protocol structure
     /// is initialized as a means of customizing its behavior,
     /// and dispatching requests immediately upon events.
-    pub fn add_handler(&mut self, handler: Arc<Handler>) {
+    pub fn add_handler(&mut self, handler: Arc<dyn Handler>) {
         self.handlers.push(handler);
     }
 
@@ -667,7 +673,7 @@ impl LightProtocol {
     /// Handle a packet using the given io context.
     /// Packet data is _untrusted_, which means that invalid data won't lead to
     /// issues.
-    pub fn handle_packet(&self, io: &IoContext, peer: PeerId, packet_id: u8, data: &[u8]) {
+    pub fn handle_packet(&self, io: &dyn IoContext, peer: PeerId, packet_id: u8, data: &[u8]) {
         let rlp = Rlp::new(data);
 
         trace!(target: "pip", "Incoming packet {} from peer {}", packet_id, peer);
@@ -694,7 +700,7 @@ impl LightProtocol {
     }
 
     // check timeouts and punish peers.
-    fn timeout_check(&self, io: &IoContext) {
+    fn timeout_check(&self, io: &dyn IoContext) {
         let now = Instant::now();
 
         // handshake timeout
@@ -735,7 +741,7 @@ impl LightProtocol {
 
     // propagate transactions to relay peers.
     // if we aren't on the mainnet, we just propagate to all relay peers
-    fn propagate_transactions(&self, io: &IoContext) {
+    fn propagate_transactions(&self, io: &dyn IoContext) {
         if self.capabilities.read().tx_relay {
             return;
         }
@@ -785,7 +791,7 @@ impl LightProtocol {
     }
 
     /// called when a peer connects.
-    pub fn on_connect(&self, peer: PeerId, io: &IoContext) {
+    pub fn on_connect(&self, peer: PeerId, io: &dyn IoContext) {
         let proto_version = match io.protocol_version(peer).ok_or(Error::WrongNetwork) {
             Ok(pv) => pv,
             Err(e) => {
@@ -837,7 +843,7 @@ impl LightProtocol {
     }
 
     /// called when a peer disconnects.
-    pub fn on_disconnect(&self, peer: PeerId, io: &IoContext) {
+    pub fn on_disconnect(&self, peer: PeerId, io: &dyn IoContext) {
         trace!(target: "pip", "Peer {} disconnecting", peer);
 
         self.pending_peers.write().remove(&peer);
@@ -865,20 +871,20 @@ impl LightProtocol {
     }
 
     /// Execute the given closure with a basic context derived from the I/O context.
-    pub fn with_context<F, T>(&self, io: &IoContext, f: F) -> T
+    pub fn with_context<F, T>(&self, io: &dyn IoContext, f: F) -> T
     where
-        F: FnOnce(&BasicContext) -> T,
+        F: FnOnce(&dyn BasicContext) -> T,
     {
         f(&TickCtx { io, proto: self })
     }
 
-    fn tick_handlers(&self, io: &IoContext) {
+    fn tick_handlers(&self, io: &dyn IoContext) {
         for handler in &self.handlers {
             handler.tick(&TickCtx { io, proto: self })
         }
     }
 
-    fn begin_new_cost_period(&self, io: &IoContext) {
+    fn begin_new_cost_period(&self, io: &dyn IoContext) {
         self.load_distribution.end_period(&*self.sample_store);
 
         let avg_peer_count = self.statistics.read().avg_peer_count();
@@ -920,7 +926,7 @@ impl LightProtocol {
 
 impl LightProtocol {
     // Handle status message from peer.
-    fn status(&self, peer: PeerId, io: &IoContext, data: &Rlp) -> Result<(), Error> {
+    fn status(&self, peer: PeerId, io: &dyn IoContext, data: &Rlp) -> Result<(), Error> {
         let pending = match self.pending_peers.write().remove(&peer) {
             Some(pending) => pending,
             None => {
@@ -992,7 +998,7 @@ impl LightProtocol {
     }
 
     // Handle an announcement.
-    fn announcement(&self, peer: PeerId, io: &IoContext, data: &Rlp) -> Result<(), Error> {
+    fn announcement(&self, peer: PeerId, io: &dyn IoContext, data: &Rlp) -> Result<(), Error> {
         if !self.peers.read().contains_key(&peer) {
             debug!(target: "pip", "Ignoring announcement from unknown peer");
             return Ok(());
@@ -1040,7 +1046,7 @@ impl LightProtocol {
     }
 
     // Receive requests from a peer.
-    fn request(&self, peer_id: PeerId, io: &IoContext, raw: &Rlp) -> Result<(), Error> {
+    fn request(&self, peer_id: PeerId, io: &dyn IoContext, raw: &Rlp) -> Result<(), Error> {
         // the maximum amount of requests we'll fill in a single packet.
         const MAX_REQUESTS: usize = 256;
 
@@ -1134,7 +1140,7 @@ impl LightProtocol {
     }
 
     // handle a packet with responses.
-    fn response(&self, peer: PeerId, io: &IoContext, raw: &Rlp) -> Result<(), Error> {
+    fn response(&self, peer: PeerId, io: &dyn IoContext, raw: &Rlp) -> Result<(), Error> {
         let (req_id, responses) = {
             let id_guard = self.pre_verify_response(peer, &raw)?;
             let responses: Vec<Response> = raw.list_at(2)?;
@@ -1157,7 +1163,7 @@ impl LightProtocol {
     }
 
     // handle an update of request credits parameters.
-    fn update_credits(&self, peer_id: PeerId, io: &IoContext, raw: &Rlp) -> Result<(), Error> {
+    fn update_credits(&self, peer_id: PeerId, io: &dyn IoContext, raw: &Rlp) -> Result<(), Error> {
         let peers = self.peers.read();
 
         let peer = peers.get(&peer_id).ok_or(Error::UnknownPeer)?;
@@ -1196,7 +1202,7 @@ impl LightProtocol {
     fn acknowledge_update(
         &self,
         peer_id: PeerId,
-        _io: &IoContext,
+        _io: &dyn IoContext,
         _raw: &Rlp,
     ) -> Result<(), Error> {
         let peers = self.peers.read();
@@ -1218,7 +1224,12 @@ impl LightProtocol {
     }
 
     // Receive a set of transactions to relay.
-    fn relay_transactions(&self, peer: PeerId, io: &IoContext, data: &Rlp) -> Result<(), Error> {
+    fn relay_transactions(
+        &self,
+        peer: PeerId,
+        io: &dyn IoContext,
+        data: &Rlp,
+    ) -> Result<(), Error> {
         const MAX_TRANSACTIONS: usize = 256;
 
         let txs: Vec<_> = data
@@ -1245,7 +1256,7 @@ impl LightProtocol {
 }
 
 // if something went wrong, figure out how much to punish the peer.
-fn punish(peer: PeerId, io: &IoContext, e: &Error) {
+fn punish(peer: PeerId, io: &dyn IoContext, e: &Error) {
     match e.punishment() {
         Punishment::None => {}
         Punishment::Disconnect => {
@@ -1260,7 +1271,7 @@ fn punish(peer: PeerId, io: &IoContext, e: &Error) {
 }
 
 impl NetworkProtocolHandler for LightProtocol {
-    fn initialize(&self, io: &NetworkContext) {
+    fn initialize(&self, io: &dyn NetworkContext) {
         io.register_timer(TIMEOUT, TIMEOUT_INTERVAL)
             .expect("Error registering sync timer.");
         io.register_timer(TICK_TIMEOUT, TICK_TIMEOUT_INTERVAL)
@@ -1273,19 +1284,19 @@ impl NetworkProtocolHandler for LightProtocol {
             .expect("Error registering statistics timer.");
     }
 
-    fn read(&self, io: &NetworkContext, peer: &PeerId, packet_id: u8, data: &[u8]) {
+    fn read(&self, io: &dyn NetworkContext, peer: &PeerId, packet_id: u8, data: &[u8]) {
         self.handle_packet(&io, *peer, packet_id, data);
     }
 
-    fn connected(&self, io: &NetworkContext, peer: &PeerId) {
+    fn connected(&self, io: &dyn NetworkContext, peer: &PeerId) {
         self.on_connect(*peer, &io);
     }
 
-    fn disconnected(&self, io: &NetworkContext, peer: &PeerId) {
+    fn disconnected(&self, io: &dyn NetworkContext, peer: &PeerId) {
         self.on_disconnect(*peer, &io);
     }
 
-    fn timeout(&self, io: &NetworkContext, timer: TimerToken) {
+    fn timeout(&self, io: &dyn NetworkContext, timer: TimerToken) {
         match timer {
             TIMEOUT => self.timeout_check(&io),
             TICK_TIMEOUT => self.tick_handlers(&io),

ethcore/light/src/on_demand/mod.rs

@@ -99,7 +99,7 @@ pub trait OnDemandRequester: Send + Sync {
     /// Fails if back-reference are not coherent.
     fn request<T>(
         &self,
-        ctx: &BasicContext,
+        ctx: &dyn BasicContext,
         requests: T,
     ) -> Result<OnResponses<T>, basic_request::NoSuchOutput>
     where
@@ -111,7 +111,7 @@ pub trait OnDemandRequester: Send + Sync {
     /// The returned vector of responses will correspond to the requests exactly.
     fn request_raw(
         &self,
-        ctx: &BasicContext,
+        ctx: &dyn BasicContext,
         requests: Vec<Request>,
     ) -> Result<Receiver<PendingResponse>, basic_request::NoSuchOutput>;
 }
@@ -396,7 +396,7 @@ pub struct OnDemand {
 impl OnDemandRequester for OnDemand {
     fn request_raw(
         &self,
-        ctx: &BasicContext,
+        ctx: &dyn BasicContext,
         requests: Vec<Request>,
     ) -> Result<Receiver<PendingResponse>, basic_request::NoSuchOutput> {
         let (sender, receiver) = oneshot::channel();
@@ -460,7 +460,7 @@ impl OnDemandRequester for OnDemand {
 
     fn request<T>(
         &self,
-        ctx: &BasicContext,
+        ctx: &dyn BasicContext,
         requests: T,
     ) -> Result<OnResponses<T>, basic_request::NoSuchOutput>
     where
@@ -543,7 +543,7 @@ impl OnDemand {
 
     // maybe dispatch pending requests.
     // sometimes
-    fn attempt_dispatch(&self, ctx: &BasicContext) {
+    fn attempt_dispatch(&self, ctx: &dyn BasicContext) {
         if !self.no_immediate_dispatch {
             self.dispatch_pending(ctx)
         }
@@ -551,7 +551,7 @@ impl OnDemand {
 
     // dispatch pending requests, and discard those for which the corresponding
     // receiver has been dropped.
-    fn dispatch_pending(&self, ctx: &BasicContext) {
+    fn dispatch_pending(&self, ctx: &dyn BasicContext) {
         if self.pending.read().is_empty() {
             return;
         }
@@ -606,7 +606,7 @@ impl OnDemand {
 
     // submit a pending request set. attempts to answer from cache before
     // going to the network. if complete, sends response and consumes the struct.
-    fn submit_pending(&self, ctx: &BasicContext, mut pending: Pending) {
+    fn submit_pending(&self, ctx: &dyn BasicContext, mut pending: Pending) {
         // answer as many requests from cache as we can, and schedule for dispatch
         // if incomplete.
 
@@ -625,7 +625,7 @@ impl OnDemand {
 impl Handler for OnDemand {
     fn on_connect(
         &self,
-        ctx: &EventContext,
+        ctx: &dyn EventContext,
         status: &Status,
         capabilities: &Capabilities,
     ) -> PeerStatus {
@@ -640,7 +640,7 @@ impl Handler for OnDemand {
         PeerStatus::Kept
     }
 
-    fn on_disconnect(&self, ctx: &EventContext, unfulfilled: &[ReqId]) {
+    fn on_disconnect(&self, ctx: &dyn EventContext, unfulfilled: &[ReqId]) {
         self.peers.write().remove(&ctx.peer());
         let ctx = ctx.as_basic();
 
@@ -657,7 +657,7 @@ impl Handler for OnDemand {
         self.attempt_dispatch(ctx);
     }
 
-    fn on_announcement(&self, ctx: &EventContext, announcement: &Announcement) {
+    fn on_announcement(&self, ctx: &dyn EventContext, announcement: &Announcement) {
         {
             let mut peers = self.peers.write();
             if let Some(ref mut peer) = peers.get_mut(&ctx.peer()) {
@@ -671,7 +671,7 @@ impl Handler for OnDemand {
 
     fn on_responses(
         &self,
-        ctx: &EventContext,
+        ctx: &dyn EventContext,
         req_id: ReqId,
         responses: &[basic_request::Response],
     ) {
@@ -713,7 +713,7 @@ impl Handler for OnDemand {
         self.submit_pending(ctx.as_basic(), pending);
     }
 
-    fn tick(&self, ctx: &BasicContext) {
+    fn tick(&self, ctx: &dyn BasicContext) {
         self.attempt_dispatch(ctx)
     }
 }

ethcore/light/src/on_demand/request.rs

@@ -1117,7 +1117,7 @@ pub struct TransactionProof {
     // TODO: it's not really possible to provide this if the header is unknown.
     pub env_info: EnvInfo,
     /// Consensus engine.
-    pub engine: Arc<EthEngine>,
+    pub engine: Arc<dyn EthEngine>,
 }
 
 impl TransactionProof {
@@ -1164,9 +1164,9 @@ pub struct Signal {
     /// Block hash and number to fetch proof for.
     pub hash: H256,
     /// Consensus engine, used to check the proof.
-    pub engine: Arc<EthEngine>,
+    pub engine: Arc<dyn EthEngine>,
     /// Special checker for the proof.
-    pub proof_check: Arc<StateDependentProof<EthereumMachine>>,
+    pub proof_check: Arc<dyn StateDependentProof<EthereumMachine>>,
 }
 
 impl Signal {

ethcore/light/src/on_demand/tests.rs

@@ -51,7 +51,7 @@ impl EventContext for Context {
         }
     }
 
-    fn as_basic(&self) -> &BasicContext {
+    fn as_basic(&self) -> &dyn BasicContext {
         self
     }
 }

ethcore/light/src/transaction_queue.rs

@@ -129,7 +129,7 @@ pub enum ImportDestination {
     Future,
 }
 
-type Listener = Box<Fn(&[H256]) + Send + Sync>;
+type Listener = Box<dyn Fn(&[H256]) + Send + Sync>;
 
 /// Light transaction queue. See module docs for more details.
 #[derive(Default)]

ethcore/node-filter/src/lib.rs

@@ -49,13 +49,13 @@ use_contract!(peer_set, "res/peer_set.json");
 
 /// Connection filter that uses a contract to manage permissions.
 pub struct NodeFilter {
-    client: Weak<BlockChainClient>,
+    client: Weak<dyn BlockChainClient>,
     contract_address: Address,
 }
 
 impl NodeFilter {
     /// Create a new instance. Accepts a contract address.
-    pub fn new(client: Weak<BlockChainClient>, contract_address: Address) -> NodeFilter {
+    pub fn new(client: Weak<dyn BlockChainClient>, contract_address: Address) -> NodeFilter {
         NodeFilter {
             client,
             contract_address,
@@ -127,7 +127,7 @@ mod test {
         )
         .unwrap();
         let filter = NodeFilter::new(
-            Arc::downgrade(&client) as Weak<BlockChainClient>,
+            Arc::downgrade(&client) as Weak<dyn BlockChainClient>,
             contract_addr,
         );
         let self1: NodeId = "00000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000002".into();

ethcore/private-tx/src/encryptor.rs

@@ -77,7 +77,7 @@ pub struct SecretStoreEncryptor {
     config: EncryptorConfig,
     client: FetchClient,
     sessions: Mutex<HashMap<Address, EncryptionSession>>,
-    signer: Arc<Signer>,
+    signer: Arc<dyn Signer>,
 }
 
 impl SecretStoreEncryptor {
@@ -85,7 +85,7 @@ impl SecretStoreEncryptor {
     pub fn new(
         config: EncryptorConfig,
         client: FetchClient,
-        signer: Arc<Signer>,
+        signer: Arc<dyn Signer>,
     ) -> Result<Self, Error> {
         Ok(SecretStoreEncryptor {
             config,

ethcore/private-tx/src/error.rs

@@ -116,7 +116,7 @@ pub enum Error {
 }
 
 impl error::Error for Error {
-    fn source(&self) -> Option<&(error::Error + 'static)> {
+    fn source(&self) -> Option<&(dyn error::Error + 'static)> {
         match self {
             Error::Io(e) => Some(e),
             Error::Decoder(e) => Some(e),

ethcore/private-tx/src/lib.rs

@@ -198,17 +198,17 @@ impl Signer for KeyPairSigner {
 
 /// Manager of private transactions
 pub struct Provider {
-    encryptor: Box<Encryptor>,
+    encryptor: Box<dyn Encryptor>,
     validator_accounts: HashSet<Address>,
     signer_account: Option<Address>,
-    notify: RwLock<Vec<Weak<ChainNotify>>>,
+    notify: RwLock<Vec<Weak<dyn ChainNotify>>>,
     transactions_for_signing: RwLock<SigningStore>,
     transactions_for_verification: VerificationStore,
     client: Arc<Client>,
     miner: Arc<Miner>,
-    accounts: Arc<Signer>,
+    accounts: Arc<dyn Signer>,
     channel: IoChannel<ClientIoMessage>,
-    keys_provider: Arc<KeyProvider>,
+    keys_provider: Arc<dyn KeyProvider>,
 }
 
 #[derive(Debug)]
@@ -228,11 +228,11 @@ impl Provider {
     pub fn new(
         client: Arc<Client>,
         miner: Arc<Miner>,
-        accounts: Arc<Signer>,
+        accounts: Arc<dyn Signer>,
-        encryptor: Box<Encryptor>,
+        encryptor: Box<dyn Encryptor>,
         config: ProviderConfig,
         channel: IoChannel<ClientIoMessage>,
-        keys_provider: Arc<KeyProvider>,
+        keys_provider: Arc<dyn KeyProvider>,
     ) -> Self {
         keys_provider.update_acl_contract();
         Provider {
@@ -253,13 +253,13 @@ impl Provider {
     // TODO [ToDr] Don't use `ChainNotify` here!
     // Better to create a separate notification type for this.
     /// Adds an actor to be notified on certain events
-    pub fn add_notify(&self, target: Arc<ChainNotify>) {
+    pub fn add_notify(&self, target: Arc<dyn ChainNotify>) {
         self.notify.write().push(Arc::downgrade(&target));
     }
 
     fn notify<F>(&self, f: F)
     where
-        F: Fn(&ChainNotify),
+        F: Fn(&dyn ChainNotify),
     {
         for np in self.notify.read().iter() {
             if let Some(n) = np.upgrade() {

ethcore/service/src/service.rs

@@ -82,7 +82,7 @@ pub struct ClientService {
     client: Arc<Client>,
     snapshot: Arc<SnapshotService>,
     private_tx: Arc<PrivateTxService>,
-    database: Arc<BlockChainDB>,
+    database: Arc<dyn BlockChainDB>,
     _stop_guard: StopGuard,
 }
 
@@ -91,13 +91,13 @@ impl ClientService {
     pub fn start(
         config: ClientConfig,
         spec: &Spec,
-        blockchain_db: Arc<BlockChainDB>,
+        blockchain_db: Arc<dyn BlockChainDB>,
         snapshot_path: &Path,
-        restoration_db_handler: Box<BlockChainDBHandler>,
+        restoration_db_handler: Box<dyn BlockChainDBHandler>,
         _ipc_path: &Path,
         miner: Arc<Miner>,
-        signer: Arc<Signer>,
+        signer: Arc<dyn Signer>,
-        encryptor: Box<ethcore_private_tx::Encryptor>,
+        encryptor: Box<dyn ethcore_private_tx::Encryptor>,
         private_tx_conf: ethcore_private_tx::ProviderConfig,
         private_encryptor_conf: ethcore_private_tx::EncryptorConfig,
     ) -> Result<ClientService, Error> {
@@ -169,7 +169,7 @@ impl ClientService {
     /// Get general IO interface
     pub fn register_io_handler(
         &self,
-        handler: Arc<IoHandler<ClientIoMessage> + Send>,
+        handler: Arc<dyn IoHandler<ClientIoMessage> + Send>,
     ) -> Result<(), IoError> {
         self.io_service.register_handler(handler)
     }
@@ -195,12 +195,12 @@ impl ClientService {
     }
 
     /// Set the actor to be notified on certain chain events
-    pub fn add_notify(&self, notify: Arc<ChainNotify>) {
+    pub fn add_notify(&self, notify: Arc<dyn ChainNotify>) {
         self.client.add_notify(notify);
     }
 
     /// Get a handle to the database.
-    pub fn db(&self) -> Arc<BlockChainDB> {
+    pub fn db(&self) -> Arc<dyn BlockChainDB> {
         self.database.clone()
     }
 

ethcore/src/account_db.rs

@@ -61,9 +61,9 @@ impl Factory {
     /// This will panic when write operations are called.
     pub fn readonly<'db>(
         &self,
-        db: &'db HashDB<KeccakHasher, DBValue>,
+        db: &'db dyn HashDB<KeccakHasher, DBValue>,
         address_hash: H256,
-    ) -> Box<HashDB<KeccakHasher, DBValue> + 'db> {
+    ) -> Box<dyn HashDB<KeccakHasher, DBValue> + 'db> {
         match *self {
             Factory::Mangled => Box::new(AccountDB::from_hash(db, address_hash)),
             Factory::Plain => Box::new(Wrapping(db)),
@@ -73,9 +73,9 @@ impl Factory {
     /// Create a new mutable hashdb.
     pub fn create<'db>(
         &self,
-        db: &'db mut HashDB<KeccakHasher, DBValue>,
+        db: &'db mut dyn HashDB<KeccakHasher, DBValue>,
         address_hash: H256,
-    ) -> Box<HashDB<KeccakHasher, DBValue> + 'db> {
+    ) -> Box<dyn HashDB<KeccakHasher, DBValue> + 'db> {
         match *self {
             Factory::Mangled => Box::new(AccountDBMut::from_hash(db, address_hash)),
             Factory::Plain => Box::new(WrappingMut(db)),
@@ -87,19 +87,19 @@ impl Factory {
 /// DB backend wrapper for Account trie
 /// Transforms trie node keys for the database
 pub struct AccountDB<'db> {
-    db: &'db HashDB<KeccakHasher, DBValue>,
+    db: &'db dyn HashDB<KeccakHasher, DBValue>,
     address_hash: H256,
 }
 
 impl<'db> AccountDB<'db> {
     /// Create a new AccountDB from an address.
     #[cfg(test)]
-    pub fn new(db: &'db HashDB<KeccakHasher, DBValue>, address: &Address) -> Self {
+    pub fn new(db: &'db dyn HashDB<KeccakHasher, DBValue>, address: &Address) -> Self {
         Self::from_hash(db, keccak(address))
     }
 
     /// Create a new AcountDB from an address' hash.
-    pub fn from_hash(db: &'db HashDB<KeccakHasher, DBValue>, address_hash: H256) -> Self {
+    pub fn from_hash(db: &'db dyn HashDB<KeccakHasher, DBValue>, address_hash: H256) -> Self {
         AccountDB {
             db: db,
             address_hash: address_hash,
@@ -108,10 +108,10 @@ impl<'db> AccountDB<'db> {
 }
 
 impl<'db> AsHashDB<KeccakHasher, DBValue> for AccountDB<'db> {
-    fn as_hash_db(&self) -> &HashDB<KeccakHasher, DBValue> {
+    fn as_hash_db(&self) -> &dyn HashDB<KeccakHasher, DBValue> {
         self
     }
-    fn as_hash_db_mut(&mut self) -> &mut HashDB<KeccakHasher, DBValue> {
+    fn as_hash_db_mut(&mut self) -> &mut dyn HashDB<KeccakHasher, DBValue> {
         self
     }
 }
@@ -146,19 +146,19 @@ impl<'db> HashDB<KeccakHasher, DBValue> for AccountDB<'db> {
 
 /// DB backend wrapper for Account trie
 pub struct AccountDBMut<'db> {
-    db: &'db mut HashDB<KeccakHasher, DBValue>,
+    db: &'db mut dyn HashDB<KeccakHasher, DBValue>,
     address_hash: H256,
 }
 
 impl<'db> AccountDBMut<'db> {
     /// Create a new AccountDB from an address.
     #[cfg(test)]
-    pub fn new(db: &'db mut HashDB<KeccakHasher, DBValue>, address: &Address) -> Self {
+    pub fn new(db: &'db mut dyn HashDB<KeccakHasher, DBValue>, address: &Address) -> Self {
         Self::from_hash(db, keccak(address))
     }
 
     /// Create a new AcountDB from an address' hash.
-    pub fn from_hash(db: &'db mut HashDB<KeccakHasher, DBValue>, address_hash: H256) -> Self {
+    pub fn from_hash(db: &'db mut dyn HashDB<KeccakHasher, DBValue>, address_hash: H256) -> Self {
         AccountDBMut {
             db: db,
             address_hash: address_hash,
@@ -217,21 +217,21 @@ impl<'db> HashDB<KeccakHasher, DBValue> for AccountDBMut<'db> {
 }
 
 impl<'db> AsHashDB<KeccakHasher, DBValue> for AccountDBMut<'db> {
-    fn as_hash_db(&self) -> &HashDB<KeccakHasher, DBValue> {
+    fn as_hash_db(&self) -> &dyn HashDB<KeccakHasher, DBValue> {
         self
     }
-    fn as_hash_db_mut(&mut self) -> &mut HashDB<KeccakHasher, DBValue> {
+    fn as_hash_db_mut(&mut self) -> &mut dyn HashDB<KeccakHasher, DBValue> {
         self
     }
 }
 
-struct Wrapping<'db>(&'db HashDB<KeccakHasher, DBValue>);
+struct Wrapping<'db>(&'db dyn HashDB<KeccakHasher, DBValue>);
 
 impl<'db> AsHashDB<KeccakHasher, DBValue> for Wrapping<'db> {
-    fn as_hash_db(&self) -> &HashDB<KeccakHasher, DBValue> {
+    fn as_hash_db(&self) -> &dyn HashDB<KeccakHasher, DBValue> {
         self
     }
-    fn as_hash_db_mut(&mut self) -> &mut HashDB<KeccakHasher, DBValue> {
+    fn as_hash_db_mut(&mut self) -> &mut dyn HashDB<KeccakHasher, DBValue> {
         self
     }
 }
@@ -264,12 +264,12 @@ impl<'db> HashDB<KeccakHasher, DBValue> for Wrapping<'db> {
     }
 }
 
-struct WrappingMut<'db>(&'db mut HashDB<KeccakHasher, DBValue>);
+struct WrappingMut<'db>(&'db mut dyn HashDB<KeccakHasher, DBValue>);
 impl<'db> AsHashDB<KeccakHasher, DBValue> for WrappingMut<'db> {
-    fn as_hash_db(&self) -> &HashDB<KeccakHasher, DBValue> {
+    fn as_hash_db(&self) -> &dyn HashDB<KeccakHasher, DBValue> {
         self
     }
-    fn as_hash_db_mut(&mut self) -> &mut HashDB<KeccakHasher, DBValue> {
+    fn as_hash_db_mut(&mut self) -> &mut dyn HashDB<KeccakHasher, DBValue> {
         self
     }
 }

ethcore/src/block.rs

@@ -61,7 +61,7 @@ use types::{
 /// maintain the system `state()`. We also archive execution receipts in preparation for later block creation.
 pub struct OpenBlock<'x> {
     block: ExecutedBlock,
-    engine: &'x EthEngine,
+    engine: &'x dyn EthEngine,
 }
 
 /// Just like `OpenBlock`, except that we've applied `Engine::on_close_block`, finished up the non-seal header fields,
@@ -163,7 +163,7 @@ pub trait Drain {
 impl<'x> OpenBlock<'x> {
     /// Create a new `OpenBlock` ready for transaction pushing.
     pub fn new<'a, I: IntoIterator<Item = ExtendedHeader>>(
-        engine: &'x EthEngine,
+        engine: &'x dyn EthEngine,
         factories: Factories,
         tracing: bool,
         db: StateDB,
@@ -421,7 +421,7 @@ impl ClosedBlock {
     }
 
     /// Given an engine reference, reopen the `ClosedBlock` into an `OpenBlock`.
-    pub fn reopen(self, engine: &EthEngine) -> OpenBlock {
+    pub fn reopen(self, engine: &dyn EthEngine) -> OpenBlock {
         // revert rewards (i.e. set state back at last transaction's state).
         let mut block = self.block;
         block.state = self.unclosed_state;
@@ -451,7 +451,7 @@ impl LockedBlock {
     /// Provide a valid seal in order to turn this into a `SealedBlock`.
     ///
     /// NOTE: This does not check the validity of `seal` with the engine.
-    pub fn seal(self, engine: &EthEngine, seal: Vec<Bytes>) -> Result<SealedBlock, Error> {
+    pub fn seal(self, engine: &dyn EthEngine, seal: Vec<Bytes>) -> Result<SealedBlock, Error> {
         let expected_seal_fields = engine.seal_fields(&self.header);
         let mut s = self;
         if seal.len() != expected_seal_fields {
@@ -472,7 +472,7 @@ impl LockedBlock {
     /// This does check the validity of `seal` with the engine.
     /// Returns the `ClosedBlock` back again if the seal is no good.
     /// TODO(https://github.com/paritytech/parity-ethereum/issues/10407): This is currently only used in POW chain call paths, we should really merge it with seal() above.
-    pub fn try_seal(self, engine: &EthEngine, seal: Vec<Bytes>) -> Result<SealedBlock, Error> {
+    pub fn try_seal(self, engine: &dyn EthEngine, seal: Vec<Bytes>) -> Result<SealedBlock, Error> {
         let mut s = self;
         s.block.header.set_seal(seal);
         s.block.header.compute_hash();
@@ -511,14 +511,14 @@ pub(crate) fn enact(
     header: Header,
     transactions: Vec<SignedTransaction>,
     uncles: Vec<Header>,
-    engine: &EthEngine,
+    engine: &dyn EthEngine,
     tracing: bool,
     db: StateDB,
     parent: &Header,
     last_hashes: Arc<LastHashes>,
     factories: Factories,
     is_epoch_begin: bool,
-    ancestry: &mut Iterator<Item = ExtendedHeader>,
+    ancestry: &mut dyn Iterator<Item = ExtendedHeader>,
 ) -> Result<LockedBlock, Error> {
     // For trace log
     let trace_state = if log_enabled!(target: "enact", ::log::Level::Trace) {
@@ -569,14 +569,14 @@ pub(crate) fn enact(
 /// Enact the block given by `block_bytes` using `engine` on the database `db` with given `parent` block header
 pub fn enact_verified(
     block: PreverifiedBlock,
-    engine: &EthEngine,
+    engine: &dyn EthEngine,
     tracing: bool,
     db: StateDB,
     parent: &Header,
     last_hashes: Arc<LastHashes>,
     factories: Factories,
     is_epoch_begin: bool,
-    ancestry: &mut Iterator<Item = ExtendedHeader>,
+    ancestry: &mut dyn Iterator<Item = ExtendedHeader>,
 ) -> Result<LockedBlock, Error> {
     enact(
         block.header,
@@ -610,7 +610,7 @@ mod tests {
     /// Enact the block given by `block_bytes` using `engine` on the database `db` with given `parent` block header
     fn enact_bytes(
         block_bytes: Vec<u8>,
-        engine: &EthEngine,
+        engine: &dyn EthEngine,
         tracing: bool,
         db: StateDB,
         parent: &Header,
@@ -667,7 +667,7 @@ mod tests {
     /// Enact the block given by `block_bytes` using `engine` on the database `db` with given `parent` block header. Seal the block aferwards
     fn enact_and_seal(
         block_bytes: Vec<u8>,
-        engine: &EthEngine,
+        engine: &dyn EthEngine,
         tracing: bool,
         db: StateDB,
         parent: &Header,

ethcore/src/client/ancient_import.rs

@@ -32,13 +32,13 @@ const HEAVY_VERIFY_RATE: f32 = 0.02;
 /// Ancient block verifier: import an ancient sequence of blocks in order from a starting
 /// epoch.
 pub struct AncientVerifier {
-    cur_verifier: RwLock<Option<Box<EpochVerifier<EthereumMachine>>>>,
+    cur_verifier: RwLock<Option<Box<dyn EpochVerifier<EthereumMachine>>>>,
-    engine: Arc<EthEngine>,
+    engine: Arc<dyn EthEngine>,
 }
 
 impl AncientVerifier {
     /// Create a new ancient block verifier with the given engine.
-    pub fn new(engine: Arc<EthEngine>) -> Self {
+    pub fn new(engine: Arc<dyn EthEngine>) -> Self {
         AncientVerifier {
             cur_verifier: RwLock::new(None),
             engine,
@@ -93,7 +93,7 @@ impl AncientVerifier {
         &self,
         header: &Header,
         chain: &BlockChain,
-    ) -> Result<Box<EpochVerifier<EthereumMachine>>, ::error::Error> {
+    ) -> Result<Box<dyn EpochVerifier<EthereumMachine>>, ::error::Error> {
         trace!(target: "client", "Initializing ancient block restoration.");
         let current_epoch_data = chain
             .epoch_transitions()

ethcore/src/client/client.rs

@@ -184,7 +184,7 @@ struct Importer {
     pub ancient_verifier: AncientVerifier,
 
     /// Ethereum engine to be used during import
-    pub engine: Arc<EthEngine>,
+    pub engine: Arc<dyn EthEngine>,
 
     /// A lru cache of recently detected bad blocks
     pub bad_blocks: bad_blocks::BadBlocks,
@@ -206,7 +206,7 @@ pub struct Client {
 
     chain: RwLock<Arc<BlockChain>>,
     tracedb: RwLock<TraceDB<BlockChain>>,
-    engine: Arc<EthEngine>,
+    engine: Arc<dyn EthEngine>,
 
     /// Client configuration
     config: ClientConfig,
@@ -261,7 +261,7 @@ pub struct Client {
 impl Importer {
     pub fn new(
         config: &ClientConfig,
-        engine: Arc<EthEngine>,
+        engine: Arc<dyn EthEngine>,
         message_channel: IoChannel<ClientIoMessage>,
         miner: Arc<Miner>,
     ) -> Result<Importer, EthcoreError> {
@@ -517,7 +517,7 @@ impl Importer {
         &self,
         unverified: Unverified,
         receipts_bytes: &[u8],
-        db: &KeyValueDB,
+        db: &dyn KeyValueDB,
         chain: &BlockChain,
     ) -> EthcoreResult<()> {
         let receipts = ::rlp::decode_list(receipts_bytes);
@@ -833,7 +833,7 @@ impl Client {
     pub fn new(
         config: ClientConfig,
         spec: &Spec,
-        db: Arc<BlockChainDB>,
+        db: Arc<dyn BlockChainDB>,
         miner: Arc<Miner>,
         message_channel: IoChannel<ClientIoMessage>,
     ) -> Result<Arc<Client>, ::error::Error> {
@@ -999,7 +999,7 @@ impl Client {
     }
 
     /// Adds an actor to be notified on certain events
-    pub fn add_notify(&self, target: Arc<ChainNotify>) {
+    pub fn add_notify(&self, target: Arc<dyn ChainNotify>) {
         self.notify.write().push(Arc::downgrade(&target));
     }
 
@@ -1015,13 +1015,13 @@ impl Client {
     }
 
     /// Returns engine reference.
-    pub fn engine(&self) -> &EthEngine {
+    pub fn engine(&self) -> &dyn EthEngine {
         &*self.engine
     }
 
     fn notify<F>(&self, f: F)
     where
-        F: Fn(&ChainNotify),
+        F: Fn(&dyn ChainNotify),
     {
         for np in &*self.notify.read() {
             if let Some(n) = np.upgrade() {
@@ -1936,7 +1936,7 @@ impl Call for Client {
 }
 
 impl EngineInfo for Client {
-    fn engine(&self) -> &EthEngine {
+    fn engine(&self) -> &dyn EthEngine {
         Client::engine(self)
     }
 }
@@ -1967,7 +1967,7 @@ impl BlockChainClient for Client {
         &self,
         block: BlockId,
         analytics: CallAnalytics,
-    ) -> Result<Box<Iterator<Item = (H256, Executed)>>, CallError> {
+    ) -> Result<Box<dyn Iterator<Item = (H256, Executed)>>, CallError> {
         let mut env_info = self.env_info(block).ok_or(CallError::StatePruned)?;
         let body = self.block_body(block).ok_or(CallError::StatePruned)?;
         let mut state = self
@@ -2895,7 +2895,7 @@ impl super::traits::EngineClient for Client {
         self.chain.read().epoch_transition_for(parent_hash)
     }
 
-    fn as_full_client(&self) -> Option<&BlockChainClient> {
+    fn as_full_client(&self) -> Option<&dyn BlockChainClient> {
         Some(self)
     }
 

ethcore/src/client/io_message.rs

@@ -47,7 +47,7 @@ impl ClientIoMessage {
 }
 
 /// A function to invoke in the client thread.
-pub struct Callback(pub Box<Fn(&Client) + Send + Sync>);
+pub struct Callback(pub Box<dyn Fn(&Client) + Send + Sync>);
 
 impl fmt::Debug for Callback {
     fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {

ethcore/src/client/test_client.rs

@@ -715,7 +715,7 @@ impl StateClient for TestBlockChainClient {
 }
 
 impl EngineInfo for TestBlockChainClient {
-    fn engine(&self) -> &EthEngine {
+    fn engine(&self) -> &dyn EthEngine {
         unimplemented!()
     }
 }
@@ -743,7 +743,7 @@ impl BlockChainClient for TestBlockChainClient {
         &self,
         _block: BlockId,
         _analytics: CallAnalytics,
-    ) -> Result<Box<Iterator<Item = (H256, Executed)>>, CallError> {
+    ) -> Result<Box<dyn Iterator<Item = (H256, Executed)>>, CallError> {
         Ok(Box::new(
             self.traces
                 .read()
@@ -1110,7 +1110,7 @@ impl super::traits::EngineClient for TestBlockChainClient {
         None
     }
 
-    fn as_full_client(&self) -> Option<&BlockChainClient> {
+    fn as_full_client(&self) -> Option<&dyn BlockChainClient> {
         Some(self)
     }
 

ethcore/src/client/trace.rs

@@ -23,11 +23,11 @@ use types::BlockNumber;
 
 impl TraceDatabaseExtras for BlockChain {
     fn block_hash(&self, block_number: BlockNumber) -> Option<H256> {
-        (self as &BlockProvider).block_hash(block_number)
+        (self as &dyn BlockProvider).block_hash(block_number)
     }
 
     fn transaction_hash(&self, block_number: BlockNumber, tx_position: usize) -> Option<H256> {
-        (self as &BlockProvider)
+        (self as &dyn BlockProvider)
             .block_hash(block_number)
             .and_then(|block_hash| {
                 let tx_address = TransactionAddress {

ethcore/src/client/traits.rs

@@ -56,7 +56,7 @@ use verification::queue::{kind::blocks::Unverified, QueueInfo as BlockQueueInfo}
 /// State information to be used during client query
 pub enum StateOrBlock {
     /// State to be used, may be pending
-    State(Box<StateInfo>),
+    State(Box<dyn StateInfo>),
 
     /// Id of an existing block from a chain to get state from
     Block(BlockId),
@@ -68,8 +68,8 @@ impl<S: StateInfo + 'static> From<S> for StateOrBlock {
     }
 }
 
-impl From<Box<StateInfo>> for StateOrBlock {
+impl From<Box<dyn StateInfo>> for StateOrBlock {
-    fn from(info: Box<StateInfo>) -> StateOrBlock {
+    fn from(info: Box<dyn StateInfo>) -> StateOrBlock {
         StateOrBlock::State(info)
     }
 }
@@ -203,7 +203,7 @@ pub trait Call {
 /// Provides `engine` method
 pub trait EngineInfo {
     /// Get underlying engine object
-    fn engine(&self) -> &EthEngine;
+    fn engine(&self) -> &dyn EthEngine;
 }
 
 /// IO operations that should off-load heavy work to another thread.
@@ -353,7 +353,7 @@ pub trait BlockChainClient:
         &self,
         block: BlockId,
         analytics: CallAnalytics,
-    ) -> Result<Box<Iterator<Item = (H256, Executed)>>, CallError>;
+    ) -> Result<Box<dyn Iterator<Item = (H256, Executed)>>, CallError>;
 
     /// Returns traces matching given filter.
     fn filter_traces(&self, filter: TraceFilter) -> Option<Vec<LocalizedTrace>>;
@@ -501,7 +501,7 @@ pub trait EngineClient: Sync + Send + ChainInfo {
     fn epoch_transition_for(&self, parent_hash: H256) -> Option<::engines::EpochTransition>;
 
     /// Attempt to cast the engine client to a full client.
-    fn as_full_client(&self) -> Option<&BlockChainClient>;
+    fn as_full_client(&self) -> Option<&dyn BlockChainClient>;
 
     /// Get a block number by ID.
     fn block_number(&self, id: BlockId) -> Option<BlockNumber>;

ethcore/src/engines/authority_round/mod.rs

@@ -72,7 +72,7 @@ pub struct AuthorityRoundParams {
     /// Starting step,
     pub start_step: Option<u64>,
     /// Valid validators.
-    pub validators: Box<ValidatorSet>,
+    pub validators: Box<dyn ValidatorSet>,
     /// Chain score validation transition block.
     pub validate_score_transition: u64,
     /// Monotonic step validation transition block.
@@ -240,9 +240,9 @@ impl EpochManager {
     // zoom to epoch for given header. returns true if succeeded, false otherwise.
     fn zoom_to(
         &mut self,
-        client: &EngineClient,
+        client: &dyn EngineClient,
         machine: &EthereumMachine,
-        validators: &ValidatorSet,
+        validators: &dyn ValidatorSet,
         header: &Header,
     ) -> bool {
         let last_was_parent = self.finality_checker.subchain_head() == Some(*header.parent_hash());
@@ -348,7 +348,7 @@ impl EmptyStep {
         }
     }
 
-    fn verify(&self, validators: &ValidatorSet) -> Result<bool, Error> {
+    fn verify(&self, validators: &dyn ValidatorSet) -> Result<bool, Error> {
         let message = keccak(empty_step_rlp(self.step, &self.parent_hash));
         let correct_proposer = step_proposer(validators, &self.parent_hash, self.step);
 
@@ -449,9 +449,9 @@ struct PermissionedStep {
 pub struct AuthorityRound {
     transition_service: IoService<()>,
     step: Arc<PermissionedStep>,
-    client: Arc<RwLock<Option<Weak<EngineClient>>>>,
+    client: Arc<RwLock<Option<Weak<dyn EngineClient>>>>,
-    signer: RwLock<Option<Box<EngineSigner>>>,
+    signer: RwLock<Option<Box<dyn EngineSigner>>>,
-    validators: Box<ValidatorSet>,
+    validators: Box<dyn ValidatorSet>,
     validate_score_transition: u64,
     validate_step_transition: u64,
     empty_steps: Mutex<BTreeSet<EmptyStep>>,
@@ -631,13 +631,18 @@ fn header_empty_steps_signers(
     }
 }
 
-fn step_proposer(validators: &ValidatorSet, bh: &H256, step: u64) -> Address {
+fn step_proposer(validators: &dyn ValidatorSet, bh: &H256, step: u64) -> Address {
     let proposer = validators.get(bh, step as usize);
     trace!(target: "engine", "Fetched proposer for step {}: {}", step, proposer);
     proposer
 }
 
-fn is_step_proposer(validators: &ValidatorSet, bh: &H256, step: u64, address: &Address) -> bool {
+fn is_step_proposer(
+    validators: &dyn ValidatorSet,
+    bh: &H256,
+    step: u64,
+    address: &Address,
+) -> bool {
     step_proposer(validators, bh, step) == *address
 }
 
@@ -671,7 +676,7 @@ fn verify_timestamp(step: &Step, header_step: u64) -> Result<(), BlockError> {
 
 fn verify_external(
     header: &Header,
-    validators: &ValidatorSet,
+    validators: &dyn ValidatorSet,
     empty_steps_transition: u64,
 ) -> Result<(), Error> {
     let header_step = header_step(header, empty_steps_transition)?;
@@ -805,7 +810,7 @@ impl AuthorityRound {
     fn epoch_set<'a>(
         &'a self,
         header: &Header,
-    ) -> Result<(CowLike<ValidatorSet, SimpleList>, BlockNumber), Error> {
+    ) -> Result<(CowLike<dyn ValidatorSet, SimpleList>, BlockNumber), Error> {
         Ok(if self.immediate_transitions {
             (CowLike::Borrowed(&*self.validators), header.number())
         } else {
@@ -903,7 +908,7 @@ impl AuthorityRound {
         header: &Header,
         current_step: u64,
         parent_step: u64,
-        validators: &ValidatorSet,
+        validators: &dyn ValidatorSet,
         set_number: u64,
     ) {
         // we're building on top of the genesis block so don't report any skipped steps
@@ -937,7 +942,7 @@ impl AuthorityRound {
     fn build_finality(
         &self,
         chain_head: &Header,
-        ancestry: &mut Iterator<Item = Header>,
+        ancestry: &mut dyn Iterator<Item = Header>,
     ) -> Vec<H256> {
         if self.immediate_transitions {
             return Vec::new();
@@ -1019,7 +1024,7 @@ fn unix_now() -> Duration {
 
 struct TransitionHandler {
     step: Arc<PermissionedStep>,
-    client: Arc<RwLock<Option<Weak<EngineClient>>>>,
+    client: Arc<RwLock<Option<Weak<dyn EngineClient>>>>,
 }
 
 const ENGINE_TIMEOUT_TOKEN: TimerToken = 23;
@@ -1306,7 +1311,7 @@ impl Engine<EthereumMachine> for AuthorityRound {
         &self,
         block: &mut ExecutedBlock,
         epoch_begin: bool,
-        _ancestry: &mut Iterator<Item = ExtendedHeader>,
+        _ancestry: &mut dyn Iterator<Item = ExtendedHeader>,
     ) -> Result<(), Error> {
         // with immediate transitions, we don't use the epoch mechanism anyway.
         // the genesis is always considered an epoch, but we ignore it intentionally.
@@ -1728,12 +1733,12 @@ impl Engine<EthereumMachine> for AuthorityRound {
         }
     }
 
-    fn register_client(&self, client: Weak<EngineClient>) {
+    fn register_client(&self, client: Weak<dyn EngineClient>) {
         *self.client.write() = Some(client.clone());
         self.validators.register_client(client);
     }
 
-    fn set_signer(&self, signer: Box<EngineSigner>) {
+    fn set_signer(&self, signer: Box<dyn EngineSigner>) {
         *self.signer.write() = Some(signer);
     }
 
@@ -1746,7 +1751,7 @@ impl Engine<EthereumMachine> for AuthorityRound {
             .sign(hash)?)
     }
 
-    fn snapshot_components(&self) -> Option<Box<::snapshot::SnapshotComponents>> {
+    fn snapshot_components(&self) -> Option<Box<dyn crate::snapshot::SnapshotComponents>> {
         if self.immediate_transitions {
             None
         } else {
@@ -1761,7 +1766,7 @@ impl Engine<EthereumMachine> for AuthorityRound {
     fn ancestry_actions(
         &self,
         header: &Header,
-        ancestry: &mut Iterator<Item = ExtendedHeader>,
+        ancestry: &mut dyn Iterator<Item = ExtendedHeader>,
     ) -> Vec<AncestryAction> {
         let finalized = self.build_finality(
             header,
@@ -2171,7 +2176,7 @@ mod tests {
         (spec, tap, accounts)
     }
 
-    fn empty_step(engine: &EthEngine, step: u64, parent_hash: &H256) -> EmptyStep {
+    fn empty_step(engine: &dyn EthEngine, step: u64, parent_hash: &H256) -> EmptyStep {
         let empty_step_rlp = super::empty_step_rlp(step, parent_hash);
         let signature = engine.sign(keccak(&empty_step_rlp)).unwrap().into();
         let parent_hash = parent_hash.clone();
@@ -2182,7 +2187,7 @@ mod tests {
         }
     }
 
-    fn sealed_empty_step(engine: &EthEngine, step: u64, parent_hash: &H256) -> SealedEmptyStep {
+    fn sealed_empty_step(engine: &dyn EthEngine, step: u64, parent_hash: &H256) -> SealedEmptyStep {
         let empty_step_rlp = super::empty_step_rlp(step, parent_hash);
         let signature = engine.sign(keccak(&empty_step_rlp)).unwrap().into();
         SealedEmptyStep { signature, step }

ethcore/src/engines/basic_authority.rs

@@ -54,7 +54,7 @@ impl super::EpochVerifier<EthereumMachine> for EpochVerifier {
     }
 }
 
-fn verify_external(header: &Header, validators: &ValidatorSet) -> Result<(), Error> {
+fn verify_external(header: &Header, validators: &dyn ValidatorSet) -> Result<(), Error> {
     use rlp::Rlp;
 
     // Check if the signature belongs to a validator, can depend on parent state.
@@ -74,8 +74,8 @@ fn verify_external(header: &Header, validators: &ValidatorSet) -> Result<(), Err
 /// Engine using `BasicAuthority`, trivial proof-of-authority consensus.
 pub struct BasicAuthority {
     machine: EthereumMachine,
-    signer: RwLock<Option<Box<EngineSigner>>>,
+    signer: RwLock<Option<Box<dyn EngineSigner>>>,
-    validators: Box<ValidatorSet>,
+    validators: Box<dyn ValidatorSet>,
 }
 
 impl BasicAuthority {
@@ -201,11 +201,11 @@ impl Engine<EthereumMachine> for BasicAuthority {
         }
     }
 
-    fn register_client(&self, client: Weak<EngineClient>) {
+    fn register_client(&self, client: Weak<dyn EngineClient>) {
         self.validators.register_client(client);
     }
 
-    fn set_signer(&self, signer: Box<EngineSigner>) {
+    fn set_signer(&self, signer: Box<dyn EngineSigner>) {
         *self.signer.write() = Some(signer);
     }
 
@@ -218,7 +218,7 @@ impl Engine<EthereumMachine> for BasicAuthority {
             .sign(hash)?)
     }
 
-    fn snapshot_components(&self) -> Option<Box<::snapshot::SnapshotComponents>> {
+    fn snapshot_components(&self) -> Option<Box<dyn crate::snapshot::SnapshotComponents>> {
         None
     }
 

ethcore/src/engines/clique/mod.rs

@@ -163,10 +163,10 @@ pub struct Clique {
     epoch_length: u64,
     period: u64,
     machine: EthereumMachine,
-    client: RwLock<Option<Weak<EngineClient>>>,
+    client: RwLock<Option<Weak<dyn EngineClient>>>,
     block_state_by_hash: RwLock<LruCache<H256, CliqueBlockState>>,
     proposals: RwLock<HashMap<Address, VoteType>>,
-    signer: RwLock<Option<Box<EngineSigner>>>,
+    signer: RwLock<Option<Box<dyn EngineSigner>>>,
 }
 
 #[cfg(test)]
@@ -175,10 +175,10 @@ pub struct Clique {
     pub epoch_length: u64,
     pub period: u64,
     pub machine: EthereumMachine,
-    pub client: RwLock<Option<Weak<EngineClient>>>,
+    pub client: RwLock<Option<Weak<dyn EngineClient>>>,
     pub block_state_by_hash: RwLock<LruCache<H256, CliqueBlockState>>,
     pub proposals: RwLock<HashMap<Address, VoteType>>,
-    pub signer: RwLock<Option<Box<EngineSigner>>>,
+    pub signer: RwLock<Option<Box<dyn EngineSigner>>>,
 }
 
 impl Clique {
@@ -383,7 +383,7 @@ impl Engine<EthereumMachine> for Clique {
         &self,
         _block: &mut ExecutedBlock,
         _epoch_begin: bool,
-        _ancestry: &mut Iterator<Item = ExtendedHeader>,
+        _ancestry: &mut dyn Iterator<Item = ExtendedHeader>,
     ) -> Result<(), Error> {
         Ok(())
     }
@@ -767,12 +767,12 @@ impl Engine<EthereumMachine> for Clique {
         }
     }
 
-    fn set_signer(&self, signer: Box<EngineSigner>) {
+    fn set_signer(&self, signer: Box<dyn EngineSigner>) {
         trace!(target: "engine", "set_signer: {}", signer.address());
         *self.signer.write() = Some(signer);
     }
 
-    fn register_client(&self, client: Weak<EngineClient>) {
+    fn register_client(&self, client: Weak<dyn EngineClient>) {
         *self.client.write() = Some(client.clone());
     }
 

ethcore/src/engines/mod.rs

@@ -181,11 +181,11 @@ pub enum Seal {
 }
 
 /// A system-calling closure. Enacts calls on a block's state from the system address.
-pub type SystemCall<'a> = FnMut(Address, Vec<u8>) -> Result<Vec<u8>, String> + 'a;
+pub type SystemCall<'a> = dyn FnMut(Address, Vec<u8>) -> Result<Vec<u8>, String> + 'a;
 
 /// A system-calling closure. Enacts calls on a block's state with code either from an on-chain contract, or hard-coded EVM or WASM (if enabled on-chain) codes.
 pub type SystemOrCodeCall<'a> =
-    FnMut(SystemOrCodeCallKind, Vec<u8>) -> Result<Vec<u8>, String> + 'a;
+    dyn FnMut(SystemOrCodeCallKind, Vec<u8>) -> Result<Vec<u8>, String> + 'a;
 
 /// Kind of SystemOrCodeCall, this is either an on-chain address, or code.
 #[derive(PartialEq, Debug, Clone)]
@@ -223,10 +223,10 @@ pub fn default_system_or_code_call<'a>(
 }
 
 /// Type alias for a function we can get headers by hash through.
-pub type Headers<'a, H> = Fn(H256) -> Option<H> + 'a;
+pub type Headers<'a, H> = dyn Fn(H256) -> Option<H> + 'a;
 
 /// Type alias for a function we can query pending transitions by block hash through.
-pub type PendingTransitionStore<'a> = Fn(H256) -> Option<epoch::PendingTransition> + 'a;
+pub type PendingTransitionStore<'a> = dyn Fn(H256) -> Option<epoch::PendingTransition> + 'a;
 
 /// Proof dependent on state.
 pub trait StateDependentProof<M: Machine>: Send + Sync {
@@ -243,16 +243,16 @@ pub enum Proof<M: Machine> {
     /// Known proof (extracted from signal)
     Known(Vec<u8>),
     /// State dependent proof.
-    WithState(Arc<StateDependentProof<M>>),
+    WithState(Arc<dyn StateDependentProof<M>>),
 }
 
 /// Generated epoch verifier.
 pub enum ConstructedVerifier<'a, M: Machine> {
     /// Fully trusted verifier.
-    Trusted(Box<EpochVerifier<M>>),
+    Trusted(Box<dyn EpochVerifier<M>>),
     /// Verifier unconfirmed. Check whether given finality proof finalizes given hash
     /// under previous epoch.
-    Unconfirmed(Box<EpochVerifier<M>>, &'a [u8], H256),
+    Unconfirmed(Box<dyn EpochVerifier<M>>, &'a [u8], H256),
     /// Error constructing verifier.
     Err(Error),
 }
@@ -260,7 +260,7 @@ pub enum ConstructedVerifier<'a, M: Machine> {
 impl<'a, M: Machine> ConstructedVerifier<'a, M> {
     /// Convert to a result, indicating that any necessary confirmation has been done
     /// already.
-    pub fn known_confirmed(self) -> Result<Box<EpochVerifier<M>>, Error> {
+    pub fn known_confirmed(self) -> Result<Box<dyn EpochVerifier<M>>, Error> {
         match self {
             ConstructedVerifier::Trusted(v) | ConstructedVerifier::Unconfirmed(v, _, _) => Ok(v),
             ConstructedVerifier::Err(e) => Err(e),
@@ -314,7 +314,7 @@ pub trait Engine<M: Machine>: Sync + Send {
         &self,
         _block: &mut ExecutedBlock,
         _epoch_begin: bool,
-        _ancestry: &mut Iterator<Item = ExtendedHeader>,
+        _ancestry: &mut dyn Iterator<Item = ExtendedHeader>,
     ) -> Result<(), M::Error> {
         Ok(())
     }
@@ -467,7 +467,7 @@ pub trait Engine<M: Machine>: Sync + Send {
     }
 
     /// Register a component which signs consensus messages.
-    fn set_signer(&self, _signer: Box<EngineSigner>) {}
+    fn set_signer(&self, _signer: Box<dyn EngineSigner>) {}
 
     /// Sign using the EngineSigner, to be used for consensus tx signing.
     fn sign(&self, _hash: H256) -> Result<Signature, M::Error> {
@@ -482,7 +482,7 @@ pub trait Engine<M: Machine>: Sync + Send {
 
     /// Create a factory for building snapshot chunks and restoring from them.
     /// Returning `None` indicates that this engine doesn't support snapshot creation.
-    fn snapshot_components(&self) -> Option<Box<SnapshotComponents>> {
+    fn snapshot_components(&self) -> Option<Box<dyn SnapshotComponents>> {
         None
     }
 
@@ -511,7 +511,7 @@ pub trait Engine<M: Machine>: Sync + Send {
     fn ancestry_actions(
         &self,
         _header: &Header,
-        _ancestry: &mut Iterator<Item = ExtendedHeader>,
+        _ancestry: &mut dyn Iterator<Item = ExtendedHeader>,
     ) -> Vec<AncestryAction> {
         Vec::new()
     }

ethcore/src/engines/null_engine.rs

@@ -117,7 +117,7 @@ impl<M: Machine> Engine<M> for NullEngine<M> {
         Ok(())
     }
 
-    fn snapshot_components(&self) -> Option<Box<::snapshot::SnapshotComponents>> {
+    fn snapshot_components(&self) -> Option<Box<dyn crate::snapshot::SnapshotComponents>> {
         Some(Box::new(::snapshot::PowSnapshot::new(10000, 10000)))
     }
 

ethcore/src/engines/signer.rs

@@ -29,7 +29,7 @@ pub trait EngineSigner: Send + Sync {
 }
 
 /// Creates a new `EngineSigner` from given key pair.
-pub fn from_keypair(keypair: ethkey::KeyPair) -> Box<EngineSigner> {
+pub fn from_keypair(keypair: ethkey::KeyPair) -> Box<dyn EngineSigner> {
     Box::new(Signer(keypair))
 }
 

ethcore/src/engines/validator_set/contract.rs

@@ -34,7 +34,7 @@ use_contract!(validator_report, "res/contracts/validator_report.json");
 pub struct ValidatorContract {
     contract_address: Address,
     validators: ValidatorSafeContract,
-    client: RwLock<Option<Weak<EngineClient>>>, // TODO [keorn]: remove
+    client: RwLock<Option<Weak<dyn EngineClient>>>, // TODO [keorn]: remove
 }
 
 impl ValidatorContract {
@@ -143,7 +143,7 @@ impl ValidatorSet for ValidatorContract {
         }
     }
 
-    fn register_client(&self, client: Weak<EngineClient>) {
+    fn register_client(&self, client: Weak<dyn EngineClient>) {
         self.validators.register_client(client.clone());
         *self.client.write() = Some(client);
     }

ethcore/src/engines/validator_set/mod.rs

@@ -40,7 +40,7 @@ use self::{contract::ValidatorContract, multi::Multi, safe_contract::ValidatorSa
 use super::SystemCall;
 
 /// Creates a validator set from spec.
-pub fn new_validator_set(spec: ValidatorSpec) -> Box<ValidatorSet> {
+pub fn new_validator_set(spec: ValidatorSpec) -> Box<dyn ValidatorSet> {
     match spec {
         ValidatorSpec::List(list) => {
             Box::new(SimpleList::new(list.into_iter().map(Into::into).collect()))
@@ -168,5 +168,5 @@ pub trait ValidatorSet: Send + Sync + 'static {
     /// Notifies about benign misbehaviour.
     fn report_benign(&self, _validator: &Address, _set_block: BlockNumber, _block: BlockNumber) {}
     /// Allows blockchain state access.
-    fn register_client(&self, _client: Weak<EngineClient>) {}
+    fn register_client(&self, _client: Weak<dyn EngineClient>) {}
 }

ethcore/src/engines/validator_set/multi.rs

@@ -27,15 +27,16 @@ use super::{SystemCall, ValidatorSet};
 use client::EngineClient;
 use machine::{AuxiliaryData, Call, EthereumMachine};
 
-type BlockNumberLookup = Box<Fn(BlockId) -> Result<BlockNumber, String> + Send + Sync + 'static>;
+type BlockNumberLookup =
+    Box<dyn Fn(BlockId) -> Result<BlockNumber, String> + Send + Sync + 'static>;
 
 pub struct Multi {
-    sets: BTreeMap<BlockNumber, Box<ValidatorSet>>,
+    sets: BTreeMap<BlockNumber, Box<dyn ValidatorSet>>,
     block_number: RwLock<BlockNumberLookup>,
 }
 
 impl Multi {
-    pub fn new(set_map: BTreeMap<BlockNumber, Box<ValidatorSet>>) -> Self {
+    pub fn new(set_map: BTreeMap<BlockNumber, Box<dyn ValidatorSet>>) -> Self {
         assert!(
             set_map.get(&0u64).is_some(),
             "ValidatorSet has to be specified from block 0."
@@ -46,7 +47,7 @@ impl Multi {
         }
     }
 
-    fn correct_set(&self, id: BlockId) -> Option<&ValidatorSet> {
+    fn correct_set(&self, id: BlockId) -> Option<&dyn ValidatorSet> {
         match self.block_number.read()(id)
             .map(|parent_block| self.correct_set_by_number(parent_block))
         {
@@ -60,7 +61,7 @@ impl Multi {
 
     // get correct set by block number, along with block number at which
     // this set was activated.
-    fn correct_set_by_number(&self, parent_block: BlockNumber) -> (BlockNumber, &ValidatorSet) {
+    fn correct_set_by_number(&self, parent_block: BlockNumber) -> (BlockNumber, &dyn ValidatorSet) {
         let (block, set) = self.sets.iter()
 			.rev()
 			.find(|&(block, _)| *block <= parent_block + 1)
@@ -165,7 +166,7 @@ impl ValidatorSet for Multi {
             .report_benign(validator, set_block, block);
     }
 
-    fn register_client(&self, client: Weak<EngineClient>) {
+    fn register_client(&self, client: Weak<dyn EngineClient>) {
         for set in self.sets.values() {
             set.register_client(client.clone());
         }
@@ -263,7 +264,7 @@ mod tests {
     fn transition_to_fixed_list_instant() {
         use super::super::SimpleList;
 
-        let mut map: BTreeMap<_, Box<ValidatorSet>> = BTreeMap::new();
+        let mut map: BTreeMap<_, Box<dyn ValidatorSet>> = BTreeMap::new();
         let list1: Vec<_> = (0..10).map(|_| Address::random()).collect();
         let list2 = {
             let mut list = list1.clone();

ethcore/src/engines/validator_set/safe_contract.rs

@@ -70,7 +70,7 @@ impl ::engines::StateDependentProof<EthereumMachine> for StateProof {
 pub struct ValidatorSafeContract {
     contract_address: Address,
     validators: RwLock<MemoryLruCache<H256, SimpleList>>,
-    client: RwLock<Option<Weak<EngineClient>>>, // TODO [keorn]: remove
+    client: RwLock<Option<Weak<dyn EngineClient>>>, // TODO [keorn]: remove
 }
 
 // first proof is just a state proof call of `getValidators` at header's state.
@@ -467,7 +467,7 @@ impl ValidatorSet for ValidatorSafeContract {
         })
     }
 
-    fn register_client(&self, client: Weak<EngineClient>) {
+    fn register_client(&self, client: Weak<dyn EngineClient>) {
         trace!(target: "engine", "Setting up contract caller.");
         *self.client.write() = Some(client);
     }

ethcore/src/engines/validator_set/simple_list.rs

@@ -114,8 +114,8 @@ impl ValidatorSet for SimpleList {
     }
 }
 
-impl AsRef<ValidatorSet> for SimpleList {
+impl AsRef<dyn ValidatorSet> for SimpleList {
-    fn as_ref(&self) -> &ValidatorSet {
+    fn as_ref(&self) -> &dyn ValidatorSet {
         self
     }
 }

ethcore/src/ethereum/ethash.rs

@@ -444,7 +444,7 @@ impl Engine<EthereumMachine> for Arc<Ethash> {
         engines::ConstructedVerifier::Trusted(Box::new(self.clone()))
     }
 
-    fn snapshot_components(&self) -> Option<Box<::snapshot::SnapshotComponents>> {
+    fn snapshot_components(&self) -> Option<Box<dyn crate::snapshot::SnapshotComponents>> {
         Some(Box::new(::snapshot::PowSnapshot::new(
             SNAPSHOT_BLOCKS,
             MAX_SNAPSHOT_BLOCKS,

ethcore/src/executive.rs

@@ -223,8 +223,8 @@ enum CallCreateExecutiveKind {
     CallBuiltin(ActionParams),
     ExecCall(ActionParams, Substate),
     ExecCreate(ActionParams, Substate),
-    ResumeCall(OriginInfo, Box<ResumeCall>, Substate),
+    ResumeCall(OriginInfo, Box<dyn ResumeCall>, Substate),
-    ResumeCreate(OriginInfo, Box<ResumeCreate>, Substate),
+    ResumeCreate(OriginInfo, Box<dyn ResumeCreate>, Substate),
 }
 
 /// Executive for a raw call/create action.

ethcore/src/factory.rs

@@ -31,7 +31,7 @@ pub struct VmFactory {
 }
 
 impl VmFactory {
-    pub fn create(&self, params: ActionParams, schedule: &Schedule, depth: usize) -> Box<Exec> {
+    pub fn create(&self, params: ActionParams, schedule: &Schedule, depth: usize) -> Box<dyn Exec> {
         if schedule.wasm.is_some()
             && params.code.as_ref().map_or(false, |code| {
                 code.len() > 4 && &code[0..4] == WASM_MAGIC_NUMBER

ethcore/src/machine/impls.rs

@@ -83,7 +83,7 @@ impl From<::ethjson::spec::EthashParams> for EthashExtensions {
 }
 
 /// Special rules to be applied to the schedule.
-pub type ScheduleCreationRules = Fn(&mut Schedule, BlockNumber) + Sync + Send;
+pub type ScheduleCreationRules = dyn Fn(&mut Schedule, BlockNumber) + Sync + Send;
 
 /// An ethereum-like state machine.
 pub struct EthereumMachine {
@@ -479,7 +479,7 @@ pub struct AuxiliaryData<'a> {
 
 /// Type alias for a function we can make calls through synchronously.
 /// Returns the call result and state proof for each call.
-pub type Call<'a> = Fn(Address, Vec<u8>) -> Result<(Vec<u8>, Vec<Vec<u8>>), String> + 'a;
+pub type Call<'a> = dyn Fn(Address, Vec<u8>) -> Result<(Vec<u8>, Vec<Vec<u8>>), String> + 'a;
 
 /// Request for auxiliary data of a block.
 #[derive(Debug, Clone, Copy, PartialEq)]
@@ -493,7 +493,7 @@ pub enum AuxiliaryRequest {
 }
 
 impl super::Machine for EthereumMachine {
-    type EngineClient = ::client::EngineClient;
+    type EngineClient = dyn crate::client::EngineClient;
 
     type Error = Error;
 

ethcore/src/miner/miner.rs

@@ -206,7 +206,7 @@ pub enum Author {
     /// Sealing block is external and we only need a reward beneficiary (i.e. PoW)
     External(Address),
     /// Sealing is done internally, we need a way to create signatures to seal block (i.e. PoA)
-    Sealer(Box<EngineSigner>),
+    Sealer(Box<dyn EngineSigner>),
 }
 
 impl Author {
@@ -242,14 +242,14 @@ pub struct Miner {
     sealing: Mutex<SealingWork>,
     params: RwLock<AuthoringParams>,
     #[cfg(feature = "work-notify")]
-    listeners: RwLock<Vec<Box<NotifyWork>>>,
+    listeners: RwLock<Vec<Box<dyn NotifyWork>>>,
     nonce_cache: NonceCache,
     gas_pricer: Mutex<GasPricer>,
     options: MinerOptions,
     // TODO [ToDr] Arc is only required because of price updater
     transaction_queue: Arc<TransactionQueue>,
-    engine: Arc<EthEngine>,
+    engine: Arc<dyn EthEngine>,
-    accounts: Arc<LocalAccounts>,
+    accounts: Arc<dyn LocalAccounts>,
     io_channel: RwLock<Option<IoChannel<ClientIoMessage>>>,
     service_transaction_checker: Option<ServiceTransactionChecker>,
 }
@@ -257,13 +257,13 @@ pub struct Miner {
 impl Miner {
     /// Push listener that will handle new jobs
     #[cfg(feature = "work-notify")]
-    pub fn add_work_listener(&self, notifier: Box<NotifyWork>) {
+    pub fn add_work_listener(&self, notifier: Box<dyn NotifyWork>) {
         self.listeners.write().push(notifier);
         self.sealing.lock().enabled = true;
     }
 
     /// Set a callback to be notified about imported transactions' hashes.
-    pub fn add_transactions_listener(&self, f: Box<Fn(&[H256]) + Send + Sync>) {
+    pub fn add_transactions_listener(&self, f: Box<dyn Fn(&[H256]) + Send + Sync>) {
         self.transaction_queue.add_listener(f);
     }
 

ethcore/src/miner/pool_client.rs

@@ -66,8 +66,8 @@ impl NonceCache {
 pub struct PoolClient<'a, C: 'a> {
     chain: &'a C,
     cached_nonces: CachedNonceClient<'a, C>,
-    engine: &'a EthEngine,
+    engine: &'a dyn EthEngine,
-    accounts: &'a LocalAccounts,
+    accounts: &'a dyn LocalAccounts,
     best_block_header: Header,
     service_transaction_checker: Option<&'a ServiceTransactionChecker>,
 }
@@ -93,8 +93,8 @@ where
     pub fn new(
         chain: &'a C,
         cache: &'a NonceCache,
-        engine: &'a EthEngine,
+        engine: &'a dyn EthEngine,
-        accounts: &'a LocalAccounts,
+        accounts: &'a dyn LocalAccounts,
         service_transaction_checker: Option<&'a ServiceTransactionChecker>,
     ) -> Self {
         let best_block_header = chain.best_block_header();

ethcore/src/miner/stratum.rs

@@ -263,7 +263,7 @@ impl Stratum {
     #[cfg(feature = "work-notify")]
     pub fn register(cfg: &Options, miner: Arc<Miner>, client: Weak<Client>) -> Result<(), Error> {
         let stratum = Stratum::start(cfg, Arc::downgrade(&miner.clone()), client)?;
-        miner.add_work_listener(Box::new(stratum) as Box<NotifyWork>);
+        miner.add_work_listener(Box::new(stratum) as Box<dyn NotifyWork>);
         Ok(())
     }
 }

ethcore/src/pod_account.rs

@@ -94,7 +94,7 @@ impl PodAccount {
     /// Place additional data into given hash DB.
     pub fn insert_additional(
         &self,
-        db: &mut HashDB<KeccakHasher, DBValue>,
+        db: &mut dyn HashDB<KeccakHasher, DBValue>,
         factory: &TrieFactory<KeccakHasher, RlpCodec>,
     ) {
         match self.code {

ethcore/src/snapshot/consensus/authority.rs

@@ -131,9 +131,9 @@ impl SnapshotComponents for PoaSnapshot {
     fn rebuilder(
         &self,
         chain: BlockChain,
-        db: Arc<BlockChainDB>,
+        db: Arc<dyn BlockChainDB>,
         manifest: &ManifestData,
-    ) -> Result<Box<Rebuilder>, ::error::Error> {
+    ) -> Result<Box<dyn Rebuilder>, ::error::Error> {
         Ok(Box::new(ChunkRebuilder {
             manifest: manifest.clone(),
             warp_target: None,
@@ -172,14 +172,14 @@ struct ChunkRebuilder {
     manifest: ManifestData,
     warp_target: Option<Header>,
     chain: BlockChain,
-    db: Arc<KeyValueDB>,
+    db: Arc<dyn KeyValueDB>,
     had_genesis: bool,
 
     // sorted vectors of unverified first blocks in a chunk
     // and epoch data from last blocks in chunks.
     // verification for these will be done at the end.
     unverified_firsts: Vec<(Header, Bytes, H256)>,
-    last_epochs: Vec<(Header, Box<EpochVerifier<EthereumMachine>>)>,
+    last_epochs: Vec<(Header, Box<dyn EpochVerifier<EthereumMachine>>)>,
 }
 
 // verified data.
@@ -191,9 +191,9 @@ struct Verified {
 impl ChunkRebuilder {
     fn verify_transition(
         &mut self,
-        last_verifier: &mut Option<Box<EpochVerifier<EthereumMachine>>>,
+        last_verifier: &mut Option<Box<dyn EpochVerifier<EthereumMachine>>>,
         transition_rlp: Rlp,
-        engine: &EthEngine,
+        engine: &dyn EthEngine,
     ) -> Result<Verified, ::error::Error> {
         use engines::ConstructedVerifier;
 
@@ -253,7 +253,7 @@ impl Rebuilder for ChunkRebuilder {
     fn feed(
         &mut self,
         chunk: &[u8],
-        engine: &EthEngine,
+        engine: &dyn EthEngine,
         abort_flag: &AtomicBool,
     ) -> Result<(), ::error::Error> {
         let rlp = Rlp::new(chunk);
@@ -384,7 +384,7 @@ impl Rebuilder for ChunkRebuilder {
         Ok(())
     }
 
-    fn finalize(&mut self, _engine: &EthEngine) -> Result<(), ::error::Error> {
+    fn finalize(&mut self, _engine: &dyn EthEngine) -> Result<(), ::error::Error> {
         if !self.had_genesis {
             return Err(Error::WrongChunkFormat("No genesis transition included.".into()).into());
         }

ethcore/src/snapshot/consensus/mod.rs

@@ -31,7 +31,7 @@ mod work;
 pub use self::{authority::*, work::*};
 
 /// A sink for produced chunks.
-pub type ChunkSink<'a> = FnMut(&[u8]) -> ::std::io::Result<()> + 'a;
+pub type ChunkSink<'a> = dyn FnMut(&[u8]) -> ::std::io::Result<()> + 'a;
 
 /// Components necessary for snapshot creation and restoration.
 pub trait SnapshotComponents: Send {
@@ -61,9 +61,9 @@ pub trait SnapshotComponents: Send {
     fn rebuilder(
         &self,
         chain: BlockChain,
-        db: Arc<BlockChainDB>,
+        db: Arc<dyn BlockChainDB>,
         manifest: &ManifestData,
-    ) -> Result<Box<Rebuilder>, ::error::Error>;
+    ) -> Result<Box<dyn Rebuilder>, ::error::Error>;
 
     /// Minimum supported snapshot version number.
     fn min_supported_version(&self) -> u64;
@@ -81,7 +81,7 @@ pub trait Rebuilder: Send {
     fn feed(
         &mut self,
         chunk: &[u8],
-        engine: &EthEngine,
+        engine: &dyn EthEngine,
         abort_flag: &AtomicBool,
     ) -> Result<(), ::error::Error>;
 
@@ -90,5 +90,5 @@ pub trait Rebuilder: Send {
     ///
     /// This should apply the necessary "glue" between chunks,
     /// and verify against the restored state.
-    fn finalize(&mut self, engine: &EthEngine) -> Result<(), ::error::Error>;
+    fn finalize(&mut self, engine: &dyn EthEngine) -> Result<(), ::error::Error>;
 }

ethcore/src/snapshot/consensus/work.rs

@@ -85,9 +85,9 @@ impl SnapshotComponents for PowSnapshot {
     fn rebuilder(
         &self,
         chain: BlockChain,
-        db: Arc<BlockChainDB>,
+        db: Arc<dyn BlockChainDB>,
         manifest: &ManifestData,
-    ) -> Result<Box<Rebuilder>, ::error::Error> {
+    ) -> Result<Box<dyn Rebuilder>, ::error::Error> {
         PowRebuilder::new(
             chain,
             db.key_value().clone(),
@@ -221,7 +221,7 @@ impl<'a> PowWorker<'a> {
 /// After all chunks have been submitted, we "glue" the chunks together.
 pub struct PowRebuilder {
     chain: BlockChain,
-    db: Arc<KeyValueDB>,
+    db: Arc<dyn KeyValueDB>,
     rng: OsRng,
     disconnected: Vec<(u64, H256)>,
     best_number: u64,
@@ -235,7 +235,7 @@ impl PowRebuilder {
     /// Create a new PowRebuilder.
     fn new(
         chain: BlockChain,
-        db: Arc<KeyValueDB>,
+        db: Arc<dyn KeyValueDB>,
         manifest: &ManifestData,
         snapshot_blocks: u64,
     ) -> Result<Self, ::error::Error> {
@@ -259,7 +259,7 @@ impl Rebuilder for PowRebuilder {
     fn feed(
         &mut self,
         chunk: &[u8],
-        engine: &EthEngine,
+        engine: &dyn EthEngine,
         abort_flag: &AtomicBool,
     ) -> Result<(), ::error::Error> {
         use ethereum_types::U256;
@@ -354,7 +354,7 @@ impl Rebuilder for PowRebuilder {
     }
 
     /// Glue together any disconnected chunks and check that the chain is complete.
-    fn finalize(&mut self, _: &EthEngine) -> Result<(), ::error::Error> {
+    fn finalize(&mut self, _: &dyn EthEngine) -> Result<(), ::error::Error> {
         let mut batch = self.db.transaction();
 
         for (first_num, first_hash) in self.disconnected.drain(..) {

ethcore/src/snapshot/service.rs

@@ -88,22 +88,22 @@ struct Restoration {
     state_chunks_left: HashSet<H256>,
     block_chunks_left: HashSet<H256>,
     state: StateRebuilder,
-    secondary: Box<Rebuilder>,
+    secondary: Box<dyn Rebuilder>,
     writer: Option<LooseWriter>,
     snappy_buffer: Bytes,
     final_state_root: H256,
     guard: Guard,
-    db: Arc<BlockChainDB>,
+    db: Arc<dyn BlockChainDB>,
 }
 
 struct RestorationParams<'a> {
     manifest: ManifestData,      // manifest to base restoration on.
     pruning: Algorithm,          // pruning algorithm for the database.
-    db: Arc<BlockChainDB>,       // database
+    db: Arc<dyn BlockChainDB>,   // database
     writer: Option<LooseWriter>, // writer for recovered snapshot.
     genesis: &'a [u8],           // genesis block of the chain.
     guard: Guard,                // guard for the restoration directory.
-    engine: &'a EthEngine,
+    engine: &'a dyn EthEngine,
 }
 
 impl Restoration {
@@ -167,7 +167,7 @@ impl Restoration {
         &mut self,
         hash: H256,
         chunk: &[u8],
-        engine: &EthEngine,
+        engine: &dyn EthEngine,
         flag: &AtomicBool,
     ) -> Result<(), Error> {
         if self.block_chunks_left.contains(&hash) {
@@ -191,7 +191,7 @@ impl Restoration {
     }
 
     // finish up restoration.
-    fn finalize(mut self, engine: &EthEngine) -> Result<(), Error> {
+    fn finalize(mut self, engine: &dyn EthEngine) -> Result<(), Error> {
         use trie::TrieError;
 
         if !self.is_done() {
@@ -238,37 +238,37 @@ pub trait SnapshotClient: BlockChainClient + BlockInfo + DatabaseRestore {}
 /// Snapshot service parameters.
 pub struct ServiceParams {
     /// The consensus engine this is built on.
-    pub engine: Arc<EthEngine>,
+    pub engine: Arc<dyn EthEngine>,
     /// The chain's genesis block.
     pub genesis_block: Bytes,
     /// State pruning algorithm.
     pub pruning: Algorithm,
     /// Handler for opening a restoration DB.
-    pub restoration_db_handler: Box<BlockChainDBHandler>,
+    pub restoration_db_handler: Box<dyn BlockChainDBHandler>,
     /// Async IO channel for sending messages.
     pub channel: Channel,
     /// The directory to put snapshots in.
     /// Usually "<chain hash>/snapshot"
     pub snapshot_root: PathBuf,
     /// A handle for database restoration.
-    pub client: Arc<SnapshotClient>,
+    pub client: Arc<dyn SnapshotClient>,
 }
 
 /// `SnapshotService` implementation.
 /// This controls taking snapshots and restoring from them.
 pub struct Service {
     restoration: Mutex<Option<Restoration>>,
-    restoration_db_handler: Box<BlockChainDBHandler>,
+    restoration_db_handler: Box<dyn BlockChainDBHandler>,
     snapshot_root: PathBuf,
     io_channel: Mutex<Channel>,
     pruning: Algorithm,
     status: Mutex<RestorationStatus>,
     reader: RwLock<Option<LooseReader>>,
-    engine: Arc<EthEngine>,
+    engine: Arc<dyn EthEngine>,
     genesis_block: Bytes,
     state_chunks: AtomicUsize,
     block_chunks: AtomicUsize,
-    client: Arc<SnapshotClient>,
+    client: Arc<dyn SnapshotClient>,
     progress: super::Progress,
     taking_snapshot: AtomicBool,
     restoring_snapshot: AtomicBool,

ethcore/src/snapshot/tests/helpers.rs

@@ -64,7 +64,7 @@ impl StateProducer {
 
     /// Tick the state producer. This alters the state, writing new data into
     /// the database.
-    pub fn tick<R: Rng>(&mut self, rng: &mut R, db: &mut HashDB<KeccakHasher, DBValue>) {
+    pub fn tick<R: Rng>(&mut self, rng: &mut R, db: &mut dyn HashDB<KeccakHasher, DBValue>) {
         // modify existing accounts.
         let mut accounts_to_modify: Vec<_> = {
             let trie = TrieDB::new(&db, &self.state_root).unwrap();
@@ -137,7 +137,7 @@ pub fn fill_storage(mut db: AccountDBMut, root: &mut H256, seed: &mut H256) {
 
 /// Take a snapshot from the given client into a temporary file.
 /// Return a snapshot reader for it.
-pub fn snap(client: &Client) -> (Box<SnapshotReader>, TempDir) {
+pub fn snap(client: &Client) -> (Box<dyn SnapshotReader>, TempDir) {
     use types::ids::BlockId;
 
     let tempdir = TempDir::new("").unwrap();
@@ -158,9 +158,9 @@ pub fn snap(client: &Client) -> (Box<SnapshotReader>, TempDir) {
 /// Restore a snapshot into a given database. This will read chunks from the given reader
 /// write into the given database.
 pub fn restore(
-    db: Arc<BlockChainDB>,
+    db: Arc<dyn BlockChainDB>,
-    engine: &EthEngine,
+    engine: &dyn EthEngine,
-    reader: &SnapshotReader,
+    reader: &dyn SnapshotReader,
     genesis: &[u8],
 ) -> Result<(), ::error::Error> {
     use snappy;

ethcore/src/snapshot/watcher.rs

@@ -78,8 +78,8 @@ impl Broadcast for Mutex<IoChannel<ClientIoMessage>> {
 /// A `ChainNotify` implementation which will trigger a snapshot event
 /// at certain block numbers.
 pub struct Watcher {
-    oracle: Box<Oracle>,
+    oracle: Box<dyn Oracle>,
-    broadcast: Box<Broadcast>,
+    broadcast: Box<dyn Broadcast>,
     period: u64,
     history: u64,
 }

ethcore/src/spec/spec.rs

@@ -402,7 +402,7 @@ pub struct Spec {
     /// User friendly spec name
     pub name: String,
     /// What engine are we using for this?
-    pub engine: Arc<EthEngine>,
+    pub engine: Arc<dyn EthEngine>,
     /// Name of the subdir inside the main data dir to use for chain data and settings.
     pub data_dir: String,
 
@@ -642,7 +642,7 @@ impl Spec {
         engine_spec: ethjson::spec::Engine,
         params: CommonParams,
         builtins: BTreeMap<Address, Builtin>,
-    ) -> Arc<EthEngine> {
+    ) -> Arc<dyn EthEngine> {
         let machine = Self::machine(&engine_spec, params, builtins);
 
         match engine_spec {

ethcore/src/state/account.rs

@@ -225,7 +225,11 @@ impl Account {
 
     /// Get (and cache) the contents of the trie's storage at `key`.
     /// Takes modified storage into account.
-    pub fn storage_at(&self, db: &HashDB<KeccakHasher, DBValue>, key: &H256) -> TrieResult<H256> {
+    pub fn storage_at(
+        &self,
+        db: &dyn HashDB<KeccakHasher, DBValue>,
+        key: &H256,
+    ) -> TrieResult<H256> {
         if let Some(value) = self.cached_storage_at(key) {
             return Ok(value);
         }
@@ -241,7 +245,7 @@ impl Account {
     /// Does not take modified storage into account.
     pub fn original_storage_at(
         &self,
-        db: &HashDB<KeccakHasher, DBValue>,
+        db: &dyn HashDB<KeccakHasher, DBValue>,
         key: &H256,
     ) -> TrieResult<H256> {
         if let Some(value) = self.cached_original_storage_at(key) {
@@ -268,7 +272,7 @@ impl Account {
     fn get_and_cache_storage(
         storage_root: &H256,
         storage_cache: &mut LruCache<H256, H256>,
-        db: &HashDB<KeccakHasher, DBValue>,
+        db: &dyn HashDB<KeccakHasher, DBValue>,
         key: &H256,
     ) -> TrieResult<H256> {
         let db = SecTrieDB::new(&db, storage_root)?;
@@ -382,7 +386,7 @@ impl Account {
 
     /// Provide a database to get `code_hash`. Should not be called if it is a contract without code. Returns the cached code, if successful.
     #[must_use]
-    pub fn cache_code(&mut self, db: &HashDB<KeccakHasher, DBValue>) -> Option<Arc<Bytes>> {
+    pub fn cache_code(&mut self, db: &dyn HashDB<KeccakHasher, DBValue>) -> Option<Arc<Bytes>> {
         // TODO: fill out self.code_cache;
         trace!(
             "Account::cache_code: ic={}; self.code_hash={:?}, self.code_cache={}",
@@ -424,7 +428,7 @@ impl Account {
     /// Provide a database to get `code_size`. Should not be called if it is a contract without code. Returns whether
     /// the cache succeeds.
     #[must_use]
-    pub fn cache_code_size(&mut self, db: &HashDB<KeccakHasher, DBValue>) -> bool {
+    pub fn cache_code_size(&mut self, db: &dyn HashDB<KeccakHasher, DBValue>) -> bool {
         // TODO: fill out self.code_cache;
         trace!(
             "Account::cache_code_size: ic={}; self.code_hash={:?}, self.code_cache={}",
@@ -531,7 +535,7 @@ impl Account {
     pub fn commit_storage(
         &mut self,
         trie_factory: &TrieFactory,
-        db: &mut HashDB<KeccakHasher, DBValue>,
+        db: &mut dyn HashDB<KeccakHasher, DBValue>,
     ) -> TrieResult<()> {
         let mut t = trie_factory.from_existing(db, &mut self.storage_root)?;
         for (k, v) in self.storage_changes.drain() {
@@ -549,7 +553,7 @@ impl Account {
     }
 
     /// Commit any unsaved code. `code_hash` will always return the hash of the `code_cache` after this.
-    pub fn commit_code(&mut self, db: &mut HashDB<KeccakHasher, DBValue>) {
+    pub fn commit_code(&mut self, db: &mut dyn HashDB<KeccakHasher, DBValue>) {
         trace!(
             "Commiting code of {:?} - {:?}, {:?}",
             self,
@@ -651,7 +655,7 @@ impl Account {
     /// this will only work correctly under a secure trie.
     pub fn prove_storage(
         &self,
-        db: &HashDB<KeccakHasher, DBValue>,
+        db: &dyn HashDB<KeccakHasher, DBValue>,
         storage_key: H256,
     ) -> TrieResult<(Vec<Bytes>, H256)> {
         let mut recorder = Recorder::new();

ethcore/src/state/backend.rs

@@ -38,10 +38,10 @@ use state::Account;
 /// State backend. See module docs for more details.
 pub trait Backend: Send {
     /// Treat the backend as a read-only hashdb.
-    fn as_hash_db(&self) -> &HashDB<KeccakHasher, DBValue>;
+    fn as_hash_db(&self) -> &dyn HashDB<KeccakHasher, DBValue>;
 
     /// Treat the backend as a writeable hashdb.
-    fn as_hash_db_mut(&mut self) -> &mut HashDB<KeccakHasher, DBValue>;
+    fn as_hash_db_mut(&mut self) -> &mut dyn HashDB<KeccakHasher, DBValue>;
 
     /// Add an account entry to the cache.
     fn add_to_account_cache(&mut self, addr: Address, data: Option<Account>, modified: bool);
@@ -121,19 +121,19 @@ impl HashDB<KeccakHasher, DBValue> for ProofCheck {
 }
 
 impl AsHashDB<KeccakHasher, DBValue> for ProofCheck {
-    fn as_hash_db(&self) -> &HashDB<KeccakHasher, DBValue> {
+    fn as_hash_db(&self) -> &dyn HashDB<KeccakHasher, DBValue> {
         self
     }
-    fn as_hash_db_mut(&mut self) -> &mut HashDB<KeccakHasher, DBValue> {
+    fn as_hash_db_mut(&mut self) -> &mut dyn HashDB<KeccakHasher, DBValue> {
         self
     }
 }
 
 impl Backend for ProofCheck {
-    fn as_hash_db(&self) -> &HashDB<KeccakHasher, DBValue> {
+    fn as_hash_db(&self) -> &dyn HashDB<KeccakHasher, DBValue> {
         self
     }
-    fn as_hash_db_mut(&mut self) -> &mut HashDB<KeccakHasher, DBValue> {
+    fn as_hash_db_mut(&mut self) -> &mut dyn HashDB<KeccakHasher, DBValue> {
         self
     }
     fn add_to_account_cache(&mut self, _addr: Address, _data: Option<Account>, _modified: bool) {}
@@ -168,7 +168,7 @@ pub struct Proving<H> {
 }
 
 impl<AH: AsKeyedHashDB + Send + Sync> AsKeyedHashDB for Proving<AH> {
-    fn as_keyed_hash_db(&self) -> &journaldb::KeyedHashDB {
+    fn as_keyed_hash_db(&self) -> &dyn journaldb::KeyedHashDB {
         self
     }
 }
@@ -176,10 +176,10 @@ impl<AH: AsKeyedHashDB + Send + Sync> AsKeyedHashDB for Proving<AH> {
 impl<AH: AsHashDB<KeccakHasher, DBValue> + Send + Sync> AsHashDB<KeccakHasher, DBValue>
     for Proving<AH>
 {
-    fn as_hash_db(&self) -> &HashDB<KeccakHasher, DBValue> {
+    fn as_hash_db(&self) -> &dyn HashDB<KeccakHasher, DBValue> {
         self
     }
-    fn as_hash_db_mut(&mut self) -> &mut HashDB<KeccakHasher, DBValue> {
+    fn as_hash_db_mut(&mut self) -> &mut dyn HashDB<KeccakHasher, DBValue> {
         self
     }
 }
@@ -226,11 +226,11 @@ impl<H: AsHashDB<KeccakHasher, DBValue> + Send + Sync> HashDB<KeccakHasher, DBVa
 }
 
 impl<H: AsHashDB<KeccakHasher, DBValue> + Send + Sync> Backend for Proving<H> {
-    fn as_hash_db(&self) -> &HashDB<KeccakHasher, DBValue> {
+    fn as_hash_db(&self) -> &dyn HashDB<KeccakHasher, DBValue> {
         self
     }
 
-    fn as_hash_db_mut(&mut self) -> &mut HashDB<KeccakHasher, DBValue> {
+    fn as_hash_db_mut(&mut self) -> &mut dyn HashDB<KeccakHasher, DBValue> {
         self
     }
 
@@ -291,11 +291,11 @@ impl<H: AsHashDB<KeccakHasher, DBValue> + Clone> Clone for Proving<H> {
 pub struct Basic<H>(pub H);
 
 impl<H: AsHashDB<KeccakHasher, DBValue> + Send + Sync> Backend for Basic<H> {
-    fn as_hash_db(&self) -> &HashDB<KeccakHasher, DBValue> {
+    fn as_hash_db(&self) -> &dyn HashDB<KeccakHasher, DBValue> {
         self.0.as_hash_db()
     }
 
-    fn as_hash_db_mut(&mut self) -> &mut HashDB<KeccakHasher, DBValue> {
+    fn as_hash_db_mut(&mut self) -> &mut dyn HashDB<KeccakHasher, DBValue> {
         self.0.as_hash_db_mut()
     }
 

ethcore/src/state/mod.rs

@@ -702,7 +702,7 @@ impl<B: Backend> State<B> {
     ) -> TrieResult<H256>
     where
         FCachedStorageAt: Fn(&Account, &H256) -> Option<H256>,
-        FStorageAt: Fn(&Account, &HashDB<KeccakHasher, DBValue>, &H256) -> TrieResult<H256>,
+        FStorageAt: Fn(&Account, &dyn HashDB<KeccakHasher, DBValue>, &H256) -> TrieResult<H256>,
     {
         // Storage key search and update works like this:
         // 1. If there's an entry for the account in the local cache check for the key and return it if found.
@@ -1287,7 +1287,7 @@ impl<B: Backend> State<B> {
         require: RequireCache,
         account: &mut Account,
         state_db: &B,
-        db: &HashDB<KeccakHasher, DBValue>,
+        db: &dyn HashDB<KeccakHasher, DBValue>,
     ) -> bool {
         if let RequireCache::None = require {
             return true;

ethcore/src/state_db.rs

@@ -109,7 +109,7 @@ struct BlockChanges {
 /// `StateDB` is propagated into the global cache.
 pub struct StateDB {
     /// Backing database.
-    db: Box<JournalDB>,
+    db: Box<dyn JournalDB>,
     /// Shared canonical state cache.
     account_cache: Arc<Mutex<AccountCache>>,
     /// DB Code cache. Maps code hashes to shared bytes.
@@ -133,7 +133,7 @@ impl StateDB {
     /// of the LRU cache in bytes. Actual used memory may (read: will) be higher due to bookkeeping.
     // TODO: make the cache size actually accurate by moving the account storage cache
     // into the `AccountCache` structure as its own `LruCache<(Address, H256), H256>`.
-    pub fn new(db: Box<JournalDB>, cache_size: usize) -> StateDB {
+    pub fn new(db: Box<dyn JournalDB>, cache_size: usize) -> StateDB {
         let bloom = Self::load_bloom(&**db.backing());
         let acc_cache_size = cache_size * ACCOUNT_CACHE_RATIO / 100;
         let code_cache_size = cache_size - acc_cache_size;
@@ -157,7 +157,7 @@ impl StateDB {
 
     /// Loads accounts bloom from the database
     /// This bloom is used to handle request for the non-existant account fast
-    pub fn load_bloom(db: &KeyValueDB) -> Bloom {
+    pub fn load_bloom(db: &dyn KeyValueDB) -> Bloom {
         let hash_count_entry = db
             .get(COL_ACCOUNT_BLOOM, ACCOUNT_BLOOM_HASHCOUNT_KEY)
             .expect("Low-level database error");
@@ -349,12 +349,12 @@ impl StateDB {
     }
 
     /// Conversion method to interpret self as `HashDB` reference
-    pub fn as_hash_db(&self) -> &HashDB<KeccakHasher, DBValue> {
+    pub fn as_hash_db(&self) -> &dyn HashDB<KeccakHasher, DBValue> {
         self.db.as_hash_db()
     }
 
     /// Conversion method to interpret self as mutable `HashDB` reference
-    pub fn as_hash_db_mut(&mut self) -> &mut HashDB<KeccakHasher, DBValue> {
+    pub fn as_hash_db_mut(&mut self) -> &mut dyn HashDB<KeccakHasher, DBValue> {
         self.db.as_hash_db_mut()
     }
 
@@ -404,7 +404,7 @@ impl StateDB {
     }
 
     /// Returns underlying `JournalDB`.
-    pub fn journal_db(&self) -> &JournalDB {
+    pub fn journal_db(&self) -> &dyn JournalDB {
         &*self.db
     }
 
@@ -453,11 +453,11 @@ impl StateDB {
 }
 
 impl state::Backend for StateDB {
-    fn as_hash_db(&self) -> &HashDB<KeccakHasher, DBValue> {
+    fn as_hash_db(&self) -> &dyn HashDB<KeccakHasher, DBValue> {
         self.db.as_hash_db()
     }
 
-    fn as_hash_db_mut(&mut self) -> &mut HashDB<KeccakHasher, DBValue> {
+    fn as_hash_db_mut(&mut self) -> &mut dyn HashDB<KeccakHasher, DBValue> {
         self.db.as_hash_db_mut()
     }
 

ethcore/src/test_helpers.rs

@@ -333,11 +333,11 @@ struct TestBlockChainDB {
     _trace_blooms_dir: TempDir,
     blooms: blooms_db::Database,
     trace_blooms: blooms_db::Database,
-    key_value: Arc<KeyValueDB>,
+    key_value: Arc<dyn KeyValueDB>,
 }
 
 impl BlockChainDB for TestBlockChainDB {
-    fn key_value(&self) -> &Arc<KeyValueDB> {
+    fn key_value(&self) -> &Arc<dyn KeyValueDB> {
         &self.key_value
     }
 
@@ -351,7 +351,7 @@ impl BlockChainDB for TestBlockChainDB {
 }
 
 /// Creates new test instance of `BlockChainDB`
-pub fn new_db() -> Arc<BlockChainDB> {
+pub fn new_db() -> Arc<dyn BlockChainDB> {
     let blooms_dir = TempDir::new("").unwrap();
     let trace_blooms_dir = TempDir::new("").unwrap();
 
@@ -367,7 +367,7 @@ pub fn new_db() -> Arc<BlockChainDB> {
 }
 
 /// Creates a new temporary `BlockChainDB` on FS
-pub fn new_temp_db(tempdir: &Path) -> Arc<BlockChainDB> {
+pub fn new_temp_db(tempdir: &Path) -> Arc<dyn BlockChainDB> {
     let blooms_dir = TempDir::new("").unwrap();
     let trace_blooms_dir = TempDir::new("").unwrap();
     let key_value_dir = tempdir.join("key_value");
@@ -387,7 +387,9 @@ pub fn new_temp_db(tempdir: &Path) -> Arc<BlockChainDB> {
 }
 
 /// Creates new instance of KeyValueDBHandler
-pub fn restoration_db_handler(config: kvdb_rocksdb::DatabaseConfig) -> Box<BlockChainDBHandler> {
+pub fn restoration_db_handler(
+    config: kvdb_rocksdb::DatabaseConfig,
+) -> Box<dyn BlockChainDBHandler> {
     struct RestorationDBHandler {
         config: kvdb_rocksdb::DatabaseConfig,
     }
@@ -395,11 +397,11 @@ pub fn restoration_db_handler(config: kvdb_rocksdb::DatabaseConfig) -> Box<Block
     struct RestorationDB {
         blooms: blooms_db::Database,
         trace_blooms: blooms_db::Database,
-        key_value: Arc<KeyValueDB>,
+        key_value: Arc<dyn KeyValueDB>,
     }
 
     impl BlockChainDB for RestorationDB {
-        fn key_value(&self) -> &Arc<KeyValueDB> {
+        fn key_value(&self) -> &Arc<dyn KeyValueDB> {
             &self.key_value
         }
 
@@ -413,7 +415,7 @@ pub fn restoration_db_handler(config: kvdb_rocksdb::DatabaseConfig) -> Box<Block
     }
 
     impl BlockChainDBHandler for RestorationDBHandler {
-        fn open(&self, db_path: &Path) -> io::Result<Arc<BlockChainDB>> {
+        fn open(&self, db_path: &Path) -> io::Result<Arc<dyn BlockChainDB>> {
             let key_value = Arc::new(kvdb_rocksdb::Database::open(
                 &self.config,
                 &db_path.to_string_lossy(),

ethcore/src/trace/db.rs

@@ -64,7 +64,7 @@ where
     /// hashes of cached traces
     cache_manager: RwLock<CacheManager<H256>>,
     /// db
-    db: Arc<BlockChainDB>,
+    db: Arc<dyn BlockChainDB>,
     /// tracing enabled
     enabled: bool,
     /// extras
@@ -76,7 +76,7 @@ where
     T: DatabaseExtras,
 {
     /// Creates new instance of `TraceDB`.
-    pub fn new(config: Config, db: Arc<BlockChainDB>, extras: Arc<T>) -> Self {
+    pub fn new(config: Config, db: Arc<dyn BlockChainDB>, extras: Arc<T>) -> Self {
         let mut batch = DBTransaction::new();
         let genesis = extras
             .block_hash(0)

ethcore/src/verification/canon_verifier.rs

@@ -31,7 +31,7 @@ impl<C: BlockInfo + CallContract> Verifier<C> for CanonVerifier {
         &self,
         header: &Header,
         parent: &Header,
-        engine: &EthEngine,
+        engine: &dyn EthEngine,
         do_full: Option<verification::FullFamilyParams<C>>,
     ) -> Result<(), Error> {
         verification::verify_block_family(header, parent, engine, do_full)
@@ -41,7 +41,7 @@ impl<C: BlockInfo + CallContract> Verifier<C> for CanonVerifier {
         verification::verify_block_final(expected, got)
     }
 
-    fn verify_block_external(&self, header: &Header, engine: &EthEngine) -> Result<(), Error> {
+    fn verify_block_external(&self, header: &Header, engine: &dyn EthEngine) -> Result<(), Error> {
         engine.verify_block_external(header)
     }
 }

ethcore/src/verification/mod.rs

@@ -46,7 +46,7 @@ pub enum VerifierType {
 }
 
 /// Create a new verifier based on type.
-pub fn new<C: BlockInfo + CallContract>(v: VerifierType) -> Box<Verifier<C>> {
+pub fn new<C: BlockInfo + CallContract>(v: VerifierType) -> Box<dyn Verifier<C>> {
     match v {
         VerifierType::Canon | VerifierType::CanonNoSeal => Box::new(CanonVerifier),
         VerifierType::Noop => Box::new(NoopVerifier),

ethcore/src/verification/noop_verifier.rs

@@ -32,7 +32,7 @@ impl<C: BlockInfo + CallContract> Verifier<C> for NoopVerifier {
         &self,
         _: &Header,
         _t: &Header,
-        _: &EthEngine,
+        _: &dyn EthEngine,
         _: Option<verification::FullFamilyParams<C>>,
     ) -> Result<(), Error> {
         Ok(())
@@ -42,7 +42,11 @@ impl<C: BlockInfo + CallContract> Verifier<C> for NoopVerifier {
         Ok(())
     }
 
-    fn verify_block_external(&self, _header: &Header, _engine: &EthEngine) -> Result<(), Error> {
+    fn verify_block_external(
+        &self,
+        _header: &Header,
+        _engine: &dyn EthEngine,
+    ) -> Result<(), Error> {
         Ok(())
     }
 }

ethcore/src/verification/queue/kind.rs

@@ -62,14 +62,14 @@ pub trait Kind: 'static + Sized + Send + Sync {
     /// Attempt to create the `Unverified` item from the input.
     fn create(
         input: Self::Input,
-        engine: &EthEngine,
+        engine: &dyn EthEngine,
         check_seal: bool,
     ) -> Result<Self::Unverified, (Self::Input, Error)>;
 
     /// Attempt to verify the `Unverified` item using the given engine.
     fn verify(
         unverified: Self::Unverified,
-        engine: &EthEngine,
+        engine: &dyn EthEngine,
         check_seal: bool,
     ) -> Result<Self::Verified, Error>;
 }
@@ -97,7 +97,7 @@ pub mod blocks {
 
         fn create(
             input: Self::Input,
-            engine: &EthEngine,
+            engine: &dyn EthEngine,
             check_seal: bool,
         ) -> Result<Self::Unverified, (Self::Input, Error)> {
             match verify_block_basic(&input, engine, check_seal) {
@@ -115,7 +115,7 @@ pub mod blocks {
 
         fn verify(
             un: Self::Unverified,
-            engine: &EthEngine,
+            engine: &dyn EthEngine,
             check_seal: bool,
         ) -> Result<Self::Verified, Error> {
             let hash = un.hash();
@@ -245,7 +245,7 @@ pub mod headers {
 
         fn create(
             input: Self::Input,
-            engine: &EthEngine,
+            engine: &dyn EthEngine,
             check_seal: bool,
         ) -> Result<Self::Unverified, (Self::Input, Error)> {
             match verify_header_params(&input, engine, true, check_seal) {
@@ -256,7 +256,7 @@ pub mod headers {
 
         fn verify(
             unverified: Self::Unverified,
-            engine: &EthEngine,
+            engine: &dyn EthEngine,
             check_seal: bool,
         ) -> Result<Self::Verified, Error> {
             match check_seal {

ethcore/src/verification/queue/mod.rs

@@ -142,7 +142,7 @@ struct Sizes {
 /// A queue of items to be verified. Sits between network or other I/O and the `BlockChain`.
 /// Keeps them in the same order as inserted, minus invalid items.
 pub struct VerificationQueue<K: Kind> {
-    engine: Arc<EthEngine>,
+    engine: Arc<dyn EthEngine>,
     more_to_verify: Arc<Condvar>,
     verification: Arc<Verification<K>>,
     deleting: Arc<AtomicBool>,
@@ -220,7 +220,7 @@ impl<K: Kind> VerificationQueue<K> {
     /// Creates a new queue instance.
     pub fn new(
         config: Config,
-        engine: Arc<EthEngine>,
+        engine: Arc<dyn EthEngine>,
         message_channel: IoChannel<ClientIoMessage>,
         check_seal: bool,
     ) -> Self {
@@ -305,7 +305,7 @@ impl<K: Kind> VerificationQueue<K> {
 
     fn verify(
         verification: Arc<Verification<K>>,
-        engine: Arc<EthEngine>,
+        engine: Arc<dyn EthEngine>,
         wait: Arc<Condvar>,
         ready: Arc<QueueSignal>,
         empty: Arc<Condvar>,

ethcore/src/verification/verification.rs

@@ -66,7 +66,7 @@ impl HeapSizeOf for PreverifiedBlock {
 /// Phase 1 quick block verification. Only does checks that are cheap. Operates on a single block
 pub fn verify_block_basic(
     block: &Unverified,
-    engine: &EthEngine,
+    engine: &dyn EthEngine,
     check_seal: bool,
 ) -> Result<(), Error> {
     verify_header_params(&block.header, engine, true, check_seal)?;
@@ -95,7 +95,7 @@ pub fn verify_block_basic(
 /// Returns a `PreverifiedBlock` structure populated with transactions
 pub fn verify_block_unordered(
     block: Unverified,
-    engine: &EthEngine,
+    engine: &dyn EthEngine,
     check_seal: bool,
 ) -> Result<PreverifiedBlock, Error> {
     let header = block.header;
@@ -140,7 +140,7 @@ pub struct FullFamilyParams<'a, C: BlockInfo + CallContract + 'a> {
     pub block: &'a PreverifiedBlock,
 
     /// Block provider to use during verification
-    pub block_provider: &'a BlockProvider,
+    pub block_provider: &'a dyn BlockProvider,
 
     /// Engine client to use during verification
     pub client: &'a C,
@@ -150,7 +150,7 @@ pub struct FullFamilyParams<'a, C: BlockInfo + CallContract + 'a> {
 pub fn verify_block_family<C: BlockInfo + CallContract>(
     header: &Header,
     parent: &Header,
-    engine: &EthEngine,
+    engine: &dyn EthEngine,
     do_full: Option<FullFamilyParams<C>>,
 ) -> Result<(), Error> {
     // TODO: verify timestamp
@@ -177,8 +177,8 @@ pub fn verify_block_family<C: BlockInfo + CallContract>(
 
 fn verify_uncles(
     block: &PreverifiedBlock,
-    bc: &BlockProvider,
+    bc: &dyn BlockProvider,
-    engine: &EthEngine,
+    engine: &dyn EthEngine,
 ) -> Result<(), Error> {
     let header = &block.header;
     let num_uncles = block.uncles.len();
@@ -319,7 +319,7 @@ pub fn verify_block_final(expected: &Header, got: &Header) -> Result<(), Error>
 /// Check basic header parameters.
 pub fn verify_header_params(
     header: &Header,
-    engine: &EthEngine,
+    engine: &dyn EthEngine,
     is_full: bool,
     check_seal: bool,
 ) -> Result<(), Error> {
@@ -418,7 +418,7 @@ pub fn verify_header_params(
 }
 
 /// Check header parameters agains parent header.
-fn verify_parent(header: &Header, parent: &Header, engine: &EthEngine) -> Result<(), Error> {
+fn verify_parent(header: &Header, parent: &Header, engine: &dyn EthEngine) -> Result<(), Error> {
     assert!(
         header.parent_hash().is_zero() || &parent.hash() == header.parent_hash(),
         "Parent hash should already have been verified; qed"
@@ -661,12 +661,12 @@ mod tests {
         }
     }
 
-    fn basic_test(bytes: &[u8], engine: &EthEngine) -> Result<(), Error> {
+    fn basic_test(bytes: &[u8], engine: &dyn EthEngine) -> Result<(), Error> {
         let unverified = Unverified::from_rlp(bytes.to_vec())?;
         verify_block_basic(&unverified, engine, true)
     }
 
-    fn family_test<BC>(bytes: &[u8], engine: &EthEngine, bc: &BC) -> Result<(), Error>
+    fn family_test<BC>(bytes: &[u8], engine: &dyn EthEngine, bc: &BC) -> Result<(), Error>
     where
         BC: BlockProvider,
     {
@@ -697,13 +697,13 @@ mod tests {
 
         let full_params = FullFamilyParams {
             block: &block,
-            block_provider: bc as &BlockProvider,
+            block_provider: bc as &dyn BlockProvider,
             client: &client,
         };
         verify_block_family(&block.header, &parent, engine, Some(full_params))
     }
 
-    fn unordered_test(bytes: &[u8], engine: &EthEngine) -> Result<(), Error> {
+    fn unordered_test(bytes: &[u8], engine: &dyn EthEngine) -> Result<(), Error> {
         let un = Unverified::from_rlp(bytes.to_vec())?;
         verify_block_unordered(un, engine, false)?;
         Ok(())

ethcore/src/verification/verifier.rs

@@ -33,12 +33,12 @@ where
         &self,
         header: &Header,
         parent: &Header,
-        engine: &EthEngine,
+        engine: &dyn EthEngine,
         do_full: Option<verification::FullFamilyParams<C>>,
     ) -> Result<(), Error>;
 
     /// Do a final verification check for an enacted header vs its expected counterpart.
     fn verify_block_final(&self, expected: &Header, got: &Header) -> Result<(), Error>;
     /// Verify a block, inspecing external state.
-    fn verify_block_external(&self, header: &Header, engine: &EthEngine) -> Result<(), Error>;
+    fn verify_block_external(&self, header: &Header, engine: &dyn EthEngine) -> Result<(), Error>;
 }

ethcore/sync/src/api.rs

@@ -218,7 +218,7 @@ impl From<light_net::Status> for PipProtocolInfo {
 /// Only works when IPC is disabled.
 pub struct AttachedProtocol {
     /// The protocol handler in question.
-    pub handler: Arc<NetworkProtocolHandler + Send + Sync>,
+    pub handler: Arc<dyn NetworkProtocolHandler + Send + Sync>,
     /// 3-character ID for the protocol.
     pub protocol_id: ProtocolId,
     /// Supported versions and their packet counts.
@@ -273,13 +273,13 @@ pub struct Params {
     /// Configuration.
     pub config: SyncConfig,
     /// Blockchain client.
-    pub chain: Arc<BlockChainClient>,
+    pub chain: Arc<dyn BlockChainClient>,
     /// Snapshot service.
-    pub snapshot_service: Arc<SnapshotService>,
+    pub snapshot_service: Arc<dyn SnapshotService>,
     /// Private tx service.
-    pub private_tx_handler: Option<Arc<PrivateTxHandler>>,
+    pub private_tx_handler: Option<Arc<dyn PrivateTxHandler>>,
     /// Light data provider.
-    pub provider: Arc<::light::Provider>,
+    pub provider: Arc<dyn crate::light::Provider>,
     /// Network layer configuration.
     pub network_config: NetworkConfiguration,
     /// Other protocols to attach.
@@ -308,7 +308,7 @@ fn light_params(
     network_id: u64,
     median_peers: f64,
     pruning_info: PruningInfo,
-    sample_store: Option<Box<SampleStore>>,
+    sample_store: Option<Box<dyn SampleStore>>,
 ) -> LightParams {
     let mut light_params = LightParams {
         network_id: network_id,
@@ -330,7 +330,7 @@ impl EthSync {
     /// Creates and register protocol with the network service
     pub fn new(
         params: Params,
-        connection_filter: Option<Arc<ConnectionFilter>>,
+        connection_filter: Option<Arc<dyn ConnectionFilter>>,
     ) -> Result<Arc<EthSync>, Error> {
         let pruning_info = params.chain.pruning_info();
         let light_proto = match params.config.serve_light {
@@ -464,9 +464,9 @@ pub(crate) const PRIORITY_TIMER_INTERVAL: Duration = Duration::from_millis(250);
 
 struct SyncProtocolHandler {
     /// Shared blockchain client.
-    chain: Arc<BlockChainClient>,
+    chain: Arc<dyn BlockChainClient>,
     /// Shared snapshot service.
-    snapshot_service: Arc<SnapshotService>,
+    snapshot_service: Arc<dyn SnapshotService>,
     /// Sync strategy
     sync: ChainSyncApi,
     /// Chain overlay used to cache data such as fork block.
@@ -474,7 +474,7 @@ struct SyncProtocolHandler {
 }
 
 impl NetworkProtocolHandler for SyncProtocolHandler {
-    fn initialize(&self, io: &NetworkContext) {
+    fn initialize(&self, io: &dyn NetworkContext) {
         if io.subprotocol_name() != WARP_SYNC_PROTOCOL_ID {
             io.register_timer(PEERS_TIMER, Duration::from_millis(700))
                 .expect("Error registering peers timer");
@@ -490,7 +490,7 @@ impl NetworkProtocolHandler for SyncProtocolHandler {
         }
     }
 
-    fn read(&self, io: &NetworkContext, peer: &PeerId, packet_id: u8, data: &[u8]) {
+    fn read(&self, io: &dyn NetworkContext, peer: &PeerId, packet_id: u8, data: &[u8]) {
         self.sync.dispatch_packet(
             &mut NetSyncIo::new(io, &*self.chain, &*self.snapshot_service, &self.overlay),
             *peer,
@@ -499,7 +499,7 @@ impl NetworkProtocolHandler for SyncProtocolHandler {
         );
     }
 
-    fn connected(&self, io: &NetworkContext, peer: &PeerId) {
+    fn connected(&self, io: &dyn NetworkContext, peer: &PeerId) {
         trace_time!("sync::connected");
         // If warp protocol is supported only allow warp handshake
         let warp_protocol = io
@@ -515,7 +515,7 @@ impl NetworkProtocolHandler for SyncProtocolHandler {
         }
     }
 
-    fn disconnected(&self, io: &NetworkContext, peer: &PeerId) {
+    fn disconnected(&self, io: &dyn NetworkContext, peer: &PeerId) {
         trace_time!("sync::disconnected");
         if io.subprotocol_name() != WARP_SYNC_PROTOCOL_ID {
             self.sync.write().on_peer_aborting(
@@ -525,7 +525,7 @@ impl NetworkProtocolHandler for SyncProtocolHandler {
         }
     }
 
-    fn timeout(&self, io: &NetworkContext, timer: TimerToken) {
+    fn timeout(&self, io: &dyn NetworkContext, timer: TimerToken) {
         trace_time!("sync::timeout");
         let mut io = NetSyncIo::new(io, &*self.chain, &*self.snapshot_service, &self.overlay);
         match timer {
@@ -697,12 +697,12 @@ impl ChainNotify for EthSync {
 
 /// PIP event handler.
 /// Simply queues transactions from light client peers.
-struct TxRelay(Arc<BlockChainClient>);
+struct TxRelay(Arc<dyn BlockChainClient>);
 
 impl LightHandler for TxRelay {
     fn on_transactions(
         &self,
-        ctx: &EventContext,
+        ctx: &dyn EventContext,
         relay: &[::types::transaction::UnverifiedTransaction],
     ) {
         trace!(target: "pip", "Relaying {} transactions from peer {}", relay.len(), ctx.peer());
@@ -730,7 +730,7 @@ pub trait ManageNetwork: Send + Sync {
     /// Returns the minimum and maximum peers.
     fn num_peers_range(&self) -> RangeInclusive<u32>;
     /// Get network context for protocol.
-    fn with_proto_context(&self, proto: ProtocolId, f: &mut FnMut(&NetworkContext));
+    fn with_proto_context(&self, proto: ProtocolId, f: &mut dyn FnMut(&dyn NetworkContext));
 }
 
 impl ManageNetwork for EthSync {
@@ -782,7 +782,7 @@ impl ManageNetwork for EthSync {
         self.network.num_peers_range()
     }
 
-    fn with_proto_context(&self, proto: ProtocolId, f: &mut FnMut(&NetworkContext)) {
+    fn with_proto_context(&self, proto: ProtocolId, f: &mut dyn FnMut(&dyn NetworkContext)) {
         self.network.with_context_eval(proto, f);
     }
 }
@@ -964,7 +964,7 @@ pub trait LightNetworkDispatcher {
     /// Execute a closure with a protocol context.
     fn with_context<F, T>(&self, f: F) -> Option<T>
     where
-        F: FnOnce(&::light::net::BasicContext) -> T;
+        F: FnOnce(&dyn crate::light::net::BasicContext) -> T;
 }
 
 /// Configuration for the light sync.
@@ -978,7 +978,7 @@ pub struct LightSyncParams<L> {
     /// Subprotocol name.
     pub subprotocol_name: [u8; 3],
     /// Other handlers to attach.
-    pub handlers: Vec<Arc<LightHandler>>,
+    pub handlers: Vec<Arc<dyn LightHandler>>,
     /// Other subprotocols to run.
     pub attached_protos: Vec<AttachedProtocol>,
 }
@@ -986,7 +986,7 @@ pub struct LightSyncParams<L> {
 /// Service for light synchronization.
 pub struct LightSync {
     proto: Arc<LightProtocol>,
-    sync: Arc<SyncInfo + Sync + Send>,
+    sync: Arc<dyn SyncInfo + Sync + Send>,
     attached_protos: Vec<AttachedProtocol>,
     network: NetworkService,
     subprotocol_name: [u8; 3],
@@ -1040,7 +1040,7 @@ impl LightSync {
 }
 
 impl ::std::ops::Deref for LightSync {
-    type Target = ::light_sync::SyncInfo;
+    type Target = dyn crate::light_sync::SyncInfo;
 
     fn deref(&self) -> &Self::Target {
         &*self.sync
@@ -1050,7 +1050,7 @@ impl ::std::ops::Deref for LightSync {
 impl LightNetworkDispatcher for LightSync {
     fn with_context<F, T>(&self, f: F) -> Option<T>
     where
-        F: FnOnce(&::light::net::BasicContext) -> T,
+        F: FnOnce(&dyn crate::light::net::BasicContext) -> T,
     {
         self.network
             .with_context_eval(self.subprotocol_name, move |ctx| {
@@ -1119,7 +1119,7 @@ impl ManageNetwork for LightSync {
         self.network.num_peers_range()
     }
 
-    fn with_proto_context(&self, proto: ProtocolId, f: &mut FnMut(&NetworkContext)) {
+    fn with_proto_context(&self, proto: ProtocolId, f: &mut dyn FnMut(&dyn NetworkContext)) {
         self.network.with_context_eval(proto, f);
     }
 }

ethcore/sync/src/block_sync.rs

@@ -231,7 +231,7 @@ impl BlockDownloader {
     /// Add new block headers.
     pub fn import_headers(
         &mut self,
-        io: &mut SyncIo,
+        io: &mut dyn SyncIo,
         r: &Rlp,
         expected_hash: H256,
     ) -> Result<DownloadAction, BlockDownloaderImportError> {
@@ -463,7 +463,7 @@ impl BlockDownloader {
         Ok(())
     }
 
-    fn start_sync_round(&mut self, io: &mut SyncIo) {
+    fn start_sync_round(&mut self, io: &mut dyn SyncIo) {
         self.state = State::ChainHead;
         trace_sync!(
             self,
@@ -541,7 +541,7 @@ impl BlockDownloader {
     pub fn request_blocks(
         &mut self,
         peer_id: PeerId,
-        io: &mut SyncIo,
+        io: &mut dyn SyncIo,
         num_active_peers: usize,
     ) -> Option<BlockRequest> {
         match self.state {
@@ -610,7 +610,11 @@ impl BlockDownloader {
 
     /// Checks if there are blocks fully downloaded that can be imported into the blockchain and does the import.
     /// Returns DownloadAction::Reset if it is imported all the the blocks it can and all downloading peers should be reset
-    pub fn collect_blocks(&mut self, io: &mut SyncIo, allow_out_of_order: bool) -> DownloadAction {
+    pub fn collect_blocks(
+        &mut self,
+        io: &mut dyn SyncIo,
+        allow_out_of_order: bool,
+    ) -> DownloadAction {
         let mut download_action = DownloadAction::None;
         let mut imported = HashSet::new();
         let blocks = self.blocks.drain();
@@ -748,7 +752,7 @@ mod tests {
     fn import_headers(
         headers: &[BlockHeader],
         downloader: &mut BlockDownloader,
-        io: &mut SyncIo,
+        io: &mut dyn SyncIo,
     ) -> Result<DownloadAction, BlockDownloaderImportError> {
         let mut stream = RlpStream::new();
         stream.append_list(headers);
@@ -761,7 +765,7 @@ mod tests {
     fn import_headers_ok(
         headers: &[BlockHeader],
         downloader: &mut BlockDownloader,
-        io: &mut SyncIo,
+        io: &mut dyn SyncIo,
     ) {
         let res = import_headers(headers, downloader, io);
         assert!(res.is_ok());

ethcore/sync/src/blocks.rs

@@ -619,7 +619,7 @@ mod test {
         client.add_blocks(100, EachBlockWith::Nothing);
         let hashes = (0..100)
             .map(|i| {
-                (&client as &BlockChainClient)
+                (&client as &dyn BlockChainClient)
                     .block_hash(BlockId::Number(i))
                     .unwrap()
             })
@@ -639,7 +639,7 @@ mod test {
         client.add_blocks(nblocks, EachBlockWith::Nothing);
         let blocks: Vec<_> = (0..nblocks)
             .map(|i| {
-                (&client as &BlockChainClient)
+                (&client as &dyn BlockChainClient)
                     .block(BlockId::Number(i as BlockNumber))
                     .unwrap()
                     .into_inner()
@@ -719,7 +719,7 @@ mod test {
         client.add_blocks(nblocks, EachBlockWith::Nothing);
         let blocks: Vec<_> = (0..nblocks)
             .map(|i| {
-                (&client as &BlockChainClient)
+                (&client as &dyn BlockChainClient)
                     .block(BlockId::Number(i as BlockNumber))
                     .unwrap()
                     .into_inner()
@@ -755,7 +755,7 @@ mod test {
         client.add_blocks(nblocks, EachBlockWith::Nothing);
         let blocks: Vec<_> = (0..nblocks)
             .map(|i| {
-                (&client as &BlockChainClient)
+                (&client as &dyn BlockChainClient)
                     .block(BlockId::Number(i as BlockNumber))
                     .unwrap()
                     .into_inner()

ethcore/sync/src/chain/handler.rs

@@ -54,7 +54,7 @@ impl SyncHandler {
     /// Handle incoming packet from peer
     pub fn on_packet(
         sync: &mut ChainSync,
-        io: &mut SyncIo,
+        io: &mut dyn SyncIo,
         peer: PeerId,
         packet_id: u8,
         data: &[u8],
@@ -102,13 +102,13 @@ impl SyncHandler {
     }
 
     /// Called when peer sends us new consensus packet
-    pub fn on_consensus_packet(io: &mut SyncIo, peer_id: PeerId, r: &Rlp) {
+    pub fn on_consensus_packet(io: &mut dyn SyncIo, peer_id: PeerId, r: &Rlp) {
         trace!(target: "sync", "Received consensus packet from {:?}", peer_id);
         io.chain().queue_consensus_message(r.as_raw().to_vec());
     }
 
     /// Called by peer when it is disconnecting
-    pub fn on_peer_aborting(sync: &mut ChainSync, io: &mut SyncIo, peer_id: PeerId) {
+    pub fn on_peer_aborting(sync: &mut ChainSync, io: &mut dyn SyncIo, peer_id: PeerId) {
         trace!(target: "sync", "== Disconnecting {}: {}", peer_id, io.peer_version(peer_id));
         sync.handshaking_peers.remove(&peer_id);
         if sync.peers.contains_key(&peer_id) {
@@ -139,7 +139,7 @@ impl SyncHandler {
     }
 
     /// Called when a new peer is connected
-    pub fn on_peer_connected(sync: &mut ChainSync, io: &mut SyncIo, peer: PeerId) {
+    pub fn on_peer_connected(sync: &mut ChainSync, io: &mut dyn SyncIo, peer: PeerId) {
         trace!(target: "sync", "== Connected {}: {}", peer, io.peer_version(peer));
         if let Err(e) = sync.send_status(io, peer) {
             debug!(target:"sync", "Error sending status request: {:?}", e);
@@ -152,7 +152,7 @@ impl SyncHandler {
     /// Called by peer once it has new block bodies
     pub fn on_peer_new_block(
         sync: &mut ChainSync,
-        io: &mut SyncIo,
+        io: &mut dyn SyncIo,
         peer_id: PeerId,
         r: &Rlp,
     ) -> Result<(), DownloaderImportError> {
@@ -221,7 +221,7 @@ impl SyncHandler {
     /// Handles `NewHashes` packet. Initiates headers download for any unknown hashes.
     pub fn on_peer_new_hashes(
         sync: &mut ChainSync,
-        io: &mut SyncIo,
+        io: &mut dyn SyncIo,
         peer_id: PeerId,
         r: &Rlp,
     ) -> Result<(), DownloaderImportError> {
@@ -305,7 +305,7 @@ impl SyncHandler {
     /// Called by peer once it has new block bodies
     fn on_peer_block_bodies(
         sync: &mut ChainSync,
-        io: &mut SyncIo,
+        io: &mut dyn SyncIo,
         peer_id: PeerId,
         r: &Rlp,
     ) -> Result<(), DownloaderImportError> {
@@ -360,7 +360,7 @@ impl SyncHandler {
 
     fn on_peer_fork_header(
         sync: &mut ChainSync,
-        io: &mut SyncIo,
+        io: &mut dyn SyncIo,
         peer_id: PeerId,
         r: &Rlp,
     ) -> Result<(), DownloaderImportError> {
@@ -404,7 +404,7 @@ impl SyncHandler {
     /// Called by peer once it has new block headers during sync
     fn on_peer_block_headers(
         sync: &mut ChainSync,
-        io: &mut SyncIo,
+        io: &mut dyn SyncIo,
         peer_id: PeerId,
         r: &Rlp,
     ) -> Result<(), DownloaderImportError> {
@@ -484,7 +484,7 @@ impl SyncHandler {
     /// Called by peer once it has new block receipts
     fn on_peer_block_receipts(
         sync: &mut ChainSync,
-        io: &mut SyncIo,
+        io: &mut dyn SyncIo,
         peer_id: PeerId,
         r: &Rlp,
     ) -> Result<(), DownloaderImportError> {
@@ -539,7 +539,7 @@ impl SyncHandler {
     /// Called when snapshot manifest is downloaded from a peer.
     fn on_snapshot_manifest(
         sync: &mut ChainSync,
-        io: &mut SyncIo,
+        io: &mut dyn SyncIo,
         peer_id: PeerId,
         r: &Rlp,
     ) -> Result<(), DownloaderImportError> {
@@ -580,7 +580,7 @@ impl SyncHandler {
     /// Called when snapshot data is downloaded from a peer.
     fn on_snapshot_data(
         sync: &mut ChainSync,
-        io: &mut SyncIo,
+        io: &mut dyn SyncIo,
         peer_id: PeerId,
         r: &Rlp,
     ) -> Result<(), DownloaderImportError> {
@@ -653,7 +653,7 @@ impl SyncHandler {
     /// Called by peer to report status
     fn on_peer_status(
         sync: &mut ChainSync,
-        io: &mut SyncIo,
+        io: &mut dyn SyncIo,
         peer_id: PeerId,
         r: &Rlp,
     ) -> Result<(), DownloaderImportError> {
@@ -768,7 +768,7 @@ impl SyncHandler {
     /// Called when peer sends us new transactions
     pub fn on_peer_transactions(
         sync: &ChainSync,
-        io: &mut SyncIo,
+        io: &mut dyn SyncIo,
         peer_id: PeerId,
         r: &Rlp,
     ) -> Result<(), PacketDecodeError> {
@@ -799,7 +799,7 @@ impl SyncHandler {
     /// Called when peer sends us signed private transaction packet
     fn on_signed_private_transaction(
         sync: &mut ChainSync,
-        _io: &mut SyncIo,
+        _io: &mut dyn SyncIo,
         peer_id: PeerId,
         r: &Rlp,
     ) -> Result<(), DownloaderImportError> {
@@ -832,7 +832,7 @@ impl SyncHandler {
     /// Called when peer sends us new private transaction packet
     fn on_private_transaction(
         sync: &mut ChainSync,
-        _io: &mut SyncIo,
+        _io: &mut dyn SyncIo,
         peer_id: PeerId,
         r: &Rlp,
     ) -> Result<(), DownloaderImportError> {

ethcore/sync/src/chain/mod.rs

@@ -392,8 +392,8 @@ impl ChainSyncApi {
     /// Creates new `ChainSyncApi`
     pub fn new(
         config: SyncConfig,
-        chain: &BlockChainClient,
+        chain: &dyn BlockChainClient,
-        private_tx_handler: Option<Arc<PrivateTxHandler>>,
+        private_tx_handler: Option<Arc<dyn PrivateTxHandler>>,
         priority_tasks: mpsc::Receiver<PriorityTask>,
     ) -> Self {
         ChainSyncApi {
@@ -429,7 +429,7 @@ impl ChainSyncApi {
     }
 
     /// Dispatch incoming requests and responses
-    pub fn dispatch_packet(&self, io: &mut SyncIo, peer: PeerId, packet_id: u8, data: &[u8]) {
+    pub fn dispatch_packet(&self, io: &mut dyn SyncIo, peer: PeerId, packet_id: u8, data: &[u8]) {
         SyncSupplier::dispatch_packet(&self.sync, io, peer, packet_id, data)
     }
 
@@ -439,7 +439,7 @@ impl ChainSyncApi {
     ///
     /// NOTE This method should only handle stuff that can be canceled and would reach other peers
     /// by other means.
-    pub fn process_priority_queue(&self, io: &mut SyncIo) {
+    pub fn process_priority_queue(&self, io: &mut dyn SyncIo) {
         fn check_deadline(deadline: Instant) -> Option<Duration> {
             let now = Instant::now();
             if now > deadline {
@@ -516,7 +516,11 @@ impl ChainSyncApi {
 // Static methods
 impl ChainSync {
     /// creates rlp to send for the tree defined by 'from' and 'to' hashes
-    fn create_new_hashes_rlp(chain: &BlockChainClient, from: &H256, to: &H256) -> Option<Bytes> {
+    fn create_new_hashes_rlp(
+        chain: &dyn BlockChainClient,
+        from: &H256,
+        to: &H256,
+    ) -> Option<Bytes> {
         match chain.tree_route(from, to) {
             Some(route) => {
                 let uncles = chain.find_uncles(from).unwrap_or_else(Vec::new);
@@ -551,7 +555,7 @@ impl ChainSync {
     }
 
     /// creates latest block rlp for the given client
-    fn create_latest_block_rlp(chain: &BlockChainClient) -> Bytes {
+    fn create_latest_block_rlp(chain: &dyn BlockChainClient) -> Bytes {
         Self::create_block_rlp(
             &chain
                 .block(BlockId::Hash(chain.chain_info().best_block_hash))
@@ -562,7 +566,7 @@ impl ChainSync {
     }
 
     /// creates given hash block rlp for the given client
-    fn create_new_block_rlp(chain: &BlockChainClient, hash: &H256) -> Bytes {
+    fn create_new_block_rlp(chain: &dyn BlockChainClient, hash: &H256) -> Bytes {
         Self::create_block_rlp(
             &chain
                 .block(BlockId::Hash(hash.clone()))
@@ -585,7 +589,7 @@ impl ChainSync {
         peers
     }
 
-    fn get_init_state(warp_sync: WarpSync, chain: &BlockChainClient) -> SyncState {
+    fn get_init_state(warp_sync: WarpSync, chain: &dyn BlockChainClient) -> SyncState {
         let best_block = chain.chain_info().best_block_number;
         match warp_sync {
             WarpSync::Enabled => SyncState::WaitingPeers,
@@ -638,7 +642,7 @@ pub struct ChainSync {
     /// Enable ancient block downloading
     download_old_blocks: bool,
     /// Shared private tx service.
-    private_tx_handler: Option<Arc<PrivateTxHandler>>,
+    private_tx_handler: Option<Arc<dyn PrivateTxHandler>>,
     /// Enable warp sync.
     warp_sync: WarpSync,
 }
@@ -647,8 +651,8 @@ impl ChainSync {
     /// Create a new instance of syncing strategy.
     pub fn new(
         config: SyncConfig,
-        chain: &BlockChainClient,
+        chain: &dyn BlockChainClient,
-        private_tx_handler: Option<Arc<PrivateTxHandler>>,
+        private_tx_handler: Option<Arc<dyn PrivateTxHandler>>,
     ) -> Self {
         let chain_info = chain.chain_info();
         let best_block = chain.chain_info().best_block_number;
@@ -744,14 +748,14 @@ impl ChainSync {
     }
 
     /// Abort all sync activity
-    pub fn abort(&mut self, io: &mut SyncIo) {
+    pub fn abort(&mut self, io: &mut dyn SyncIo) {
         self.reset_and_continue(io);
         self.peers.clear();
     }
 
     /// Reset sync. Clear all downloaded data but keep the queue.
     /// Set sync state to the given state or to the initial state if `None` is provided.
-    fn reset(&mut self, io: &mut SyncIo, state: Option<SyncState>) {
+    fn reset(&mut self, io: &mut dyn SyncIo, state: Option<SyncState>) {
         self.new_blocks.reset();
         let chain_info = io.chain().chain_info();
         for (_, ref mut p) in &mut self.peers {
@@ -770,7 +774,7 @@ impl ChainSync {
     }
 
     /// Restart sync
-    pub fn reset_and_continue(&mut self, io: &mut SyncIo) {
+    pub fn reset_and_continue(&mut self, io: &mut dyn SyncIo) {
         trace!(target: "sync", "Restarting");
         if self.state == SyncState::SnapshotData {
             debug!(target:"sync", "Aborting snapshot restore");
@@ -783,12 +787,12 @@ impl ChainSync {
 
     /// Remove peer from active peer set. Peer will be reactivated on the next sync
     /// round.
-    fn deactivate_peer(&mut self, _io: &mut SyncIo, peer_id: PeerId) {
+    fn deactivate_peer(&mut self, _io: &mut dyn SyncIo, peer_id: PeerId) {
         trace!(target: "sync", "Deactivating peer {}", peer_id);
         self.active_peers.remove(&peer_id);
     }
 
-    fn maybe_start_snapshot_sync(&mut self, io: &mut SyncIo) {
+    fn maybe_start_snapshot_sync(&mut self, io: &mut dyn SyncIo) {
         if !self.warp_sync.is_enabled() || io.snapshot_service().supported_versions().is_none() {
             trace!(target: "sync", "Skipping warp sync. Disabled or not supported.");
             return;
@@ -868,7 +872,7 @@ impl ChainSync {
         }
     }
 
-    fn start_snapshot_sync(&mut self, io: &mut SyncIo, peers: &[PeerId]) {
+    fn start_snapshot_sync(&mut self, io: &mut dyn SyncIo, peers: &[PeerId]) {
         if !self.snapshot.have_manifest() {
             for p in peers {
                 if self
@@ -888,13 +892,13 @@ impl ChainSync {
     }
 
     /// Restart sync disregarding the block queue status. May end up re-downloading up to QUEUE_SIZE blocks
-    pub fn restart(&mut self, io: &mut SyncIo) {
+    pub fn restart(&mut self, io: &mut dyn SyncIo) {
         self.update_targets(io.chain());
         self.reset_and_continue(io);
     }
 
     /// Update sync after the blockchain has been changed externally.
-    pub fn update_targets(&mut self, chain: &BlockChainClient) {
+    pub fn update_targets(&mut self, chain: &dyn BlockChainClient) {
         // Do not assume that the block queue/chain still has our last_imported_block
         let chain = chain.chain_info();
         self.new_blocks = BlockDownloader::new(
@@ -923,7 +927,7 @@ impl ChainSync {
     }
 
     /// Resume downloading
-    pub fn continue_sync(&mut self, io: &mut SyncIo) {
+    pub fn continue_sync(&mut self, io: &mut dyn SyncIo) {
         if self.state == SyncState::Waiting {
             trace!(target: "sync", "Waiting for the block queue");
         } else if self.state == SyncState::SnapshotWaiting {
@@ -974,7 +978,7 @@ impl ChainSync {
     }
 
     /// Called after all blocks have been downloaded
-    fn complete_sync(&mut self, io: &mut SyncIo) {
+    fn complete_sync(&mut self, io: &mut dyn SyncIo) {
         trace!(target: "sync", "Sync complete");
         self.reset(io, Some(SyncState::Idle));
     }
@@ -986,7 +990,7 @@ impl ChainSync {
     }
 
     /// Find something to do for a peer. Called for a new peer or when a peer is done with its task.
-    fn sync_peer(&mut self, io: &mut SyncIo, peer_id: PeerId, force: bool) {
+    fn sync_peer(&mut self, io: &mut dyn SyncIo, peer_id: PeerId, force: bool) {
         if !self.active_peers.contains(&peer_id) {
             trace!(target: "sync", "Skipping deactivated peer {}", peer_id);
             return;
@@ -1136,7 +1140,7 @@ impl ChainSync {
     }
 
     /// Checks if there are blocks fully downloaded that can be imported into the blockchain and does the import.
-    fn collect_blocks(&mut self, io: &mut SyncIo, block_set: BlockSet) {
+    fn collect_blocks(&mut self, io: &mut dyn SyncIo, block_set: BlockSet) {
         match block_set {
             BlockSet::NewBlocks => {
                 if self
@@ -1201,7 +1205,7 @@ impl ChainSync {
     }
 
     /// Send Status message
-    fn send_status(&mut self, io: &mut SyncIo, peer: PeerId) -> Result<(), network::Error> {
+    fn send_status(&mut self, io: &mut dyn SyncIo, peer: PeerId) -> Result<(), network::Error> {
         let warp_protocol_version = io.protocol_version(&WARP_SYNC_PROTOCOL_ID, peer);
         let warp_protocol = warp_protocol_version != 0;
         let private_tx_protocol = warp_protocol_version >= PAR_PROTOCOL_VERSION_3.0;
@@ -1233,7 +1237,7 @@ impl ChainSync {
         io.respond(StatusPacket.id(), packet.out())
     }
 
-    pub fn maintain_peers(&mut self, io: &mut SyncIo) {
+    pub fn maintain_peers(&mut self, io: &mut dyn SyncIo) {
         let tick = Instant::now();
         let mut aborting = Vec::new();
         for (peer_id, peer) in &self.peers {
@@ -1267,7 +1271,7 @@ impl ChainSync {
         }
     }
 
-    fn check_resume(&mut self, io: &mut SyncIo) {
+    fn check_resume(&mut self, io: &mut dyn SyncIo) {
         match self.state {
             SyncState::Waiting if !io.chain().queue_info().is_full() => {
                 self.state = SyncState::Blocks;
@@ -1369,7 +1373,7 @@ impl ChainSync {
     }
 
     /// Maintain other peers. Send out any new blocks and transactions
-    pub fn maintain_sync(&mut self, io: &mut SyncIo) {
+    pub fn maintain_sync(&mut self, io: &mut dyn SyncIo) {
         self.maybe_start_snapshot_sync(io);
         self.check_resume(io);
     }
@@ -1377,7 +1381,7 @@ impl ChainSync {
     /// called when block is imported to chain - propagates the blocks and updates transactions sent to peers
     pub fn chain_new_blocks(
         &mut self,
-        io: &mut SyncIo,
+        io: &mut dyn SyncIo,
         _imported: &[H256],
         invalid: &[H256],
         enacted: &[H256],
@@ -1409,22 +1413,22 @@ impl ChainSync {
         }
     }
 
-    pub fn on_packet(&mut self, io: &mut SyncIo, peer: PeerId, packet_id: u8, data: &[u8]) {
+    pub fn on_packet(&mut self, io: &mut dyn SyncIo, peer: PeerId, packet_id: u8, data: &[u8]) {
         SyncHandler::on_packet(self, io, peer, packet_id, data);
     }
 
     /// Called by peer when it is disconnecting
-    pub fn on_peer_aborting(&mut self, io: &mut SyncIo, peer: PeerId) {
+    pub fn on_peer_aborting(&mut self, io: &mut dyn SyncIo, peer: PeerId) {
         SyncHandler::on_peer_aborting(self, io, peer);
     }
 
     /// Called when a new peer is connected
-    pub fn on_peer_connected(&mut self, io: &mut SyncIo, peer: PeerId) {
+    pub fn on_peer_connected(&mut self, io: &mut dyn SyncIo, peer: PeerId) {
         SyncHandler::on_peer_connected(self, io, peer);
     }
 
     /// propagates new transactions to all peers
-    pub fn propagate_new_transactions(&mut self, io: &mut SyncIo) {
+    pub fn propagate_new_transactions(&mut self, io: &mut dyn SyncIo) {
         let deadline = Instant::now() + Duration::from_millis(500);
         SyncPropagator::propagate_new_transactions(self, io, || {
             if deadline > Instant::now() {
@@ -1437,14 +1441,14 @@ impl ChainSync {
     }
 
     /// Broadcast consensus message to peers.
-    pub fn propagate_consensus_packet(&mut self, io: &mut SyncIo, packet: Bytes) {
+    pub fn propagate_consensus_packet(&mut self, io: &mut dyn SyncIo, packet: Bytes) {
         SyncPropagator::propagate_consensus_packet(self, io, packet);
     }
 
     /// Broadcast private transaction message to peers.
     pub fn propagate_private_transaction(
         &mut self,
-        io: &mut SyncIo,
+        io: &mut dyn SyncIo,
         transaction_hash: H256,
         packet_id: SyncPacket,
         packet: Bytes,
@@ -1558,7 +1562,10 @@ pub mod tests {
         assert!(!sync_status(SyncState::Idle).is_syncing(queue_info(0, 0)));
     }
 
-    pub fn dummy_sync_with_peer(peer_latest_hash: H256, client: &BlockChainClient) -> ChainSync {
+    pub fn dummy_sync_with_peer(
+        peer_latest_hash: H256,
+        client: &dyn BlockChainClient,
+    ) -> ChainSync {
         let mut sync = ChainSync::new(SyncConfig::default(), client, None);
         insert_dummy_peer(&mut sync, 0, peer_latest_hash);
         sync

ethcore/sync/src/chain/propagator.rs

@@ -43,13 +43,13 @@ impl SyncPropagator {
     pub fn propagate_blocks(
         sync: &mut ChainSync,
         chain_info: &BlockChainInfo,
-        io: &mut SyncIo,
+        io: &mut dyn SyncIo,
         blocks: &[H256],
         peers: &[PeerId],
     ) -> usize {
         trace!(target: "sync", "Sending NewBlocks to {:?}", peers);
         let sent = peers.len();
-        let mut send_packet = |io: &mut SyncIo, rlp: Bytes| {
+        let mut send_packet = |io: &mut dyn SyncIo, rlp: Bytes| {
             for peer_id in peers {
                 SyncPropagator::send_packet(io, *peer_id, NewBlockPacket, rlp.clone());
 
@@ -76,7 +76,7 @@ impl SyncPropagator {
     pub fn propagate_new_hashes(
         sync: &mut ChainSync,
         chain_info: &BlockChainInfo,
-        io: &mut SyncIo,
+        io: &mut dyn SyncIo,
         peers: &[PeerId],
     ) -> usize {
         trace!(target: "sync", "Sending NewHashes to {:?}", peers);
@@ -101,7 +101,7 @@ impl SyncPropagator {
     /// propagates new transactions to all peers
     pub fn propagate_new_transactions<F: FnMut() -> bool>(
         sync: &mut ChainSync,
-        io: &mut SyncIo,
+        io: &mut dyn SyncIo,
         mut should_continue: F,
     ) -> usize {
         // Early out if nobody to send to.
@@ -159,7 +159,7 @@ impl SyncPropagator {
 
     fn propagate_transactions_to_peers<F: FnMut() -> bool>(
         sync: &mut ChainSync,
-        io: &mut SyncIo,
+        io: &mut dyn SyncIo,
         peers: Vec<PeerId>,
         transactions: Vec<&SignedTransaction>,
         mut should_continue: F,
@@ -179,7 +179,7 @@ impl SyncPropagator {
         // Clear old transactions from stats
         sync.transactions_stats.retain(&all_transactions_hashes);
 
-        let send_packet = |io: &mut SyncIo, peer_id: PeerId, sent: usize, rlp: Bytes| {
+        let send_packet = |io: &mut dyn SyncIo, peer_id: PeerId, sent: usize, rlp: Bytes| {
             let size = rlp.len();
             SyncPropagator::send_packet(io, peer_id, TransactionsPacket, rlp);
             trace!(target: "sync", "{:02} <- Transactions ({} entries; {} bytes)", peer_id, sent, size);
@@ -279,7 +279,7 @@ impl SyncPropagator {
         sent_to_peers
     }
 
-    pub fn propagate_latest_blocks(sync: &mut ChainSync, io: &mut SyncIo, sealed: &[H256]) {
+    pub fn propagate_latest_blocks(sync: &mut ChainSync, io: &mut dyn SyncIo, sealed: &[H256]) {
         let chain_info = io.chain().chain_info();
         if (((chain_info.best_block_number as i64) - (sync.last_sent_block_number as i64)).abs()
             as BlockNumber)
@@ -304,7 +304,11 @@ impl SyncPropagator {
     }
 
     /// Distribute valid proposed blocks to subset of current peers.
-    pub fn propagate_proposed_blocks(sync: &mut ChainSync, io: &mut SyncIo, proposed: &[Bytes]) {
+    pub fn propagate_proposed_blocks(
+        sync: &mut ChainSync,
+        io: &mut dyn SyncIo,
+        proposed: &[Bytes],
+    ) {
         let peers = sync.get_consensus_peers();
         trace!(target: "sync", "Sending proposed blocks to {:?}", peers);
         for block in proposed {
@@ -316,7 +320,7 @@ impl SyncPropagator {
     }
 
     /// Broadcast consensus message to peers.
-    pub fn propagate_consensus_packet(sync: &mut ChainSync, io: &mut SyncIo, packet: Bytes) {
+    pub fn propagate_consensus_packet(sync: &mut ChainSync, io: &mut dyn SyncIo, packet: Bytes) {
         let lucky_peers = ChainSync::select_random_peers(&sync.get_consensus_peers());
         trace!(target: "sync", "Sending consensus packet to {:?}", lucky_peers);
         for peer_id in lucky_peers {
@@ -327,7 +331,7 @@ impl SyncPropagator {
     /// Broadcast private transaction message to peers.
     pub fn propagate_private_transaction(
         sync: &mut ChainSync,
-        io: &mut SyncIo,
+        io: &mut dyn SyncIo,
         transaction_hash: H256,
         packet_id: SyncPacket,
         packet: Bytes,
@@ -367,7 +371,12 @@ impl SyncPropagator {
     }
 
     /// Generic packet sender
-    pub fn send_packet(sync: &mut SyncIo, peer_id: PeerId, packet_id: SyncPacket, packet: Bytes) {
+    pub fn send_packet(
+        sync: &mut dyn SyncIo,
+        peer_id: PeerId,
+        packet_id: SyncPacket,
+        packet: Bytes,
+    ) {
         if let Err(e) = sync.send(peer_id, packet_id, packet) {
             debug!(target:"sync", "Error sending packet: {:?}", e);
             sync.disconnect_peer(peer_id);

ethcore/sync/src/chain/requester.rs

@@ -40,7 +40,7 @@ impl SyncRequester {
     /// Perform block download request`
     pub fn request_blocks(
         sync: &mut ChainSync,
-        io: &mut SyncIo,
+        io: &mut dyn SyncIo,
         peer_id: PeerId,
         request: BlockRequest,
         block_set: BlockSet,
@@ -63,7 +63,7 @@ impl SyncRequester {
     /// Request block bodies from a peer
     fn request_bodies(
         sync: &mut ChainSync,
-        io: &mut SyncIo,
+        io: &mut dyn SyncIo,
         peer_id: PeerId,
         hashes: Vec<H256>,
         set: BlockSet,
@@ -89,7 +89,7 @@ impl SyncRequester {
     /// Request headers from a peer by block number
     pub fn request_fork_header(
         sync: &mut ChainSync,
-        io: &mut SyncIo,
+        io: &mut dyn SyncIo,
         peer_id: PeerId,
         n: BlockNumber,
     ) {
@@ -110,7 +110,7 @@ impl SyncRequester {
     }
 
     /// Find some headers or blocks to download for a peer.
-    pub fn request_snapshot_data(sync: &mut ChainSync, io: &mut SyncIo, peer_id: PeerId) {
+    pub fn request_snapshot_data(sync: &mut ChainSync, io: &mut dyn SyncIo, peer_id: PeerId) {
         // find chunk data to download
         if let Some(hash) = sync.snapshot.needed_chunk() {
             if let Some(ref mut peer) = sync.peers.get_mut(&peer_id) {
@@ -121,7 +121,7 @@ impl SyncRequester {
     }
 
     /// Request snapshot manifest from a peer.
-    pub fn request_snapshot_manifest(sync: &mut ChainSync, io: &mut SyncIo, peer_id: PeerId) {
+    pub fn request_snapshot_manifest(sync: &mut ChainSync, io: &mut dyn SyncIo, peer_id: PeerId) {
         trace!(target: "sync", "{} <- GetSnapshotManifest", peer_id);
         let rlp = RlpStream::new_list(0);
         SyncRequester::send_request(
@@ -137,7 +137,7 @@ impl SyncRequester {
     /// Request headers from a peer by block hash
     fn request_headers_by_hash(
         sync: &mut ChainSync,
-        io: &mut SyncIo,
+        io: &mut dyn SyncIo,
         peer_id: PeerId,
         h: &H256,
         count: u64,
@@ -167,7 +167,7 @@ impl SyncRequester {
     /// Request block receipts from a peer
     fn request_receipts(
         sync: &mut ChainSync,
-        io: &mut SyncIo,
+        io: &mut dyn SyncIo,
         peer_id: PeerId,
         hashes: Vec<H256>,
         set: BlockSet,
@@ -193,7 +193,7 @@ impl SyncRequester {
     /// Request snapshot chunk from a peer.
     fn request_snapshot_chunk(
         sync: &mut ChainSync,
-        io: &mut SyncIo,
+        io: &mut dyn SyncIo,
         peer_id: PeerId,
         chunk: &H256,
     ) {
@@ -213,7 +213,7 @@ impl SyncRequester {
     /// Generic request sender
     fn send_request(
         sync: &mut ChainSync,
-        io: &mut SyncIo,
+        io: &mut dyn SyncIo,
         peer_id: PeerId,
         asking: PeerAsking,
         packet_id: SyncPacket,

ethcore/sync/src/chain/supplier.rs

@@ -49,7 +49,7 @@ impl SyncSupplier {
     // to chain sync from the outside world.
     pub fn dispatch_packet(
         sync: &RwLock<ChainSync>,
-        io: &mut SyncIo,
+        io: &mut dyn SyncIo,
         peer: PeerId,
         packet_id: u8,
         data: &[u8],
@@ -143,7 +143,7 @@ impl SyncSupplier {
     }
 
     /// Respond to GetBlockHeaders request
-    fn return_block_headers(io: &SyncIo, r: &Rlp, peer_id: PeerId) -> RlpResponseResult {
+    fn return_block_headers(io: &dyn SyncIo, r: &Rlp, peer_id: PeerId) -> RlpResponseResult {
         let payload_soft_limit = io.payload_soft_limit();
         // Packet layout:
         // [ block: { P , B_32 }, maxHeaders: P, skip: P, reverse: P in { 0 , 1 } ]
@@ -226,7 +226,7 @@ impl SyncSupplier {
     }
 
     /// Respond to GetBlockBodies request
-    fn return_block_bodies(io: &SyncIo, r: &Rlp, peer_id: PeerId) -> RlpResponseResult {
+    fn return_block_bodies(io: &dyn SyncIo, r: &Rlp, peer_id: PeerId) -> RlpResponseResult {
         let payload_soft_limit = io.payload_soft_limit();
         let mut count = r.item_count().unwrap_or(0);
         if count == 0 {
@@ -253,7 +253,7 @@ impl SyncSupplier {
     }
 
     /// Respond to GetNodeData request
-    fn return_node_data(io: &SyncIo, r: &Rlp, peer_id: PeerId) -> RlpResponseResult {
+    fn return_node_data(io: &dyn SyncIo, r: &Rlp, peer_id: PeerId) -> RlpResponseResult {
         let payload_soft_limit = io.payload_soft_limit();
         let mut count = r.item_count().unwrap_or(0);
         trace!(target: "sync", "{} -> GetNodeData: {} entries", peer_id, count);
@@ -284,7 +284,7 @@ impl SyncSupplier {
         Ok(Some((NodeDataPacket.id(), rlp)))
     }
 
-    fn return_receipts(io: &SyncIo, rlp: &Rlp, peer_id: PeerId) -> RlpResponseResult {
+    fn return_receipts(io: &dyn SyncIo, rlp: &Rlp, peer_id: PeerId) -> RlpResponseResult {
         let payload_soft_limit = io.payload_soft_limit();
         let mut count = rlp.item_count().unwrap_or(0);
         trace!(target: "sync", "{} -> GetReceipts: {} entries", peer_id, count);
@@ -313,7 +313,7 @@ impl SyncSupplier {
     }
 
     /// Respond to GetSnapshotManifest request
-    fn return_snapshot_manifest(io: &SyncIo, r: &Rlp, peer_id: PeerId) -> RlpResponseResult {
+    fn return_snapshot_manifest(io: &dyn SyncIo, r: &Rlp, peer_id: PeerId) -> RlpResponseResult {
         let count = r.item_count().unwrap_or(0);
         trace!(target: "warp", "{} -> GetSnapshotManifest", peer_id);
         if count != 0 {
@@ -336,7 +336,7 @@ impl SyncSupplier {
     }
 
     /// Respond to GetSnapshotData request
-    fn return_snapshot_data(io: &SyncIo, r: &Rlp, peer_id: PeerId) -> RlpResponseResult {
+    fn return_snapshot_data(io: &dyn SyncIo, r: &Rlp, peer_id: PeerId) -> RlpResponseResult {
         let hash: H256 = r.val_at(0)?;
         trace!(target: "warp", "{} -> GetSnapshotData {:?}", peer_id, hash);
         let rlp = match io.snapshot_service().chunk(hash) {
@@ -355,14 +355,14 @@ impl SyncSupplier {
     }
 
     fn return_rlp<FRlp, FError>(
-        io: &mut SyncIo,
+        io: &mut dyn SyncIo,
         rlp: &Rlp,
         peer: PeerId,
         rlp_func: FRlp,
         error_func: FError,
     ) -> Result<(), PacketDecodeError>
     where
-        FRlp: Fn(&SyncIo, &Rlp, PeerId) -> RlpResponseResult,
+        FRlp: Fn(&dyn SyncIo, &Rlp, PeerId) -> RlpResponseResult,
         FError: FnOnce(network::Error) -> String,
     {
         let response = rlp_func(io, rlp, peer);
@@ -420,7 +420,7 @@ mod test {
         client.add_blocks(100, EachBlockWith::Nothing);
         let blocks: Vec<_> = (0..100)
             .map(|i| {
-                (&client as &BlockChainClient)
+                (&client as &dyn BlockChainClient)
                     .block(BlockId::Number(i as BlockNumber))
                     .map(|b| b.into_inner())
                     .unwrap()

ethcore/sync/src/light_sync/mod.rs

@@ -118,7 +118,7 @@ impl AncestorSearch {
         }
     }
 
-    fn process_response<L>(self, ctx: &ResponseContext, client: &L) -> AncestorSearch
+    fn process_response<L>(self, ctx: &dyn ResponseContext, client: &L) -> AncestorSearch
     where
         L: AsLightClient,
     {
@@ -261,7 +261,7 @@ impl Deref for SyncStateWrapper {
 struct ResponseCtx<'a> {
     peer: PeerId,
     req_id: ReqId,
-    ctx: &'a BasicContext,
+    ctx: &'a dyn BasicContext,
     data: &'a [encoded::Header],
 }
 
@@ -302,7 +302,7 @@ struct PendingReq {
 impl<L: AsLightClient + Send + Sync> Handler for LightSync<L> {
     fn on_connect(
         &self,
-        ctx: &EventContext,
+        ctx: &dyn EventContext,
         status: &Status,
         capabilities: &Capabilities,
     ) -> PeerStatus {
@@ -331,7 +331,7 @@ impl<L: AsLightClient + Send + Sync> Handler for LightSync<L> {
         }
     }
 
-    fn on_disconnect(&self, ctx: &EventContext, unfulfilled: &[ReqId]) {
+    fn on_disconnect(&self, ctx: &dyn EventContext, unfulfilled: &[ReqId]) {
         let peer_id = ctx.peer();
 
         let peer = match self.peers.write().remove(&peer_id).map(|p| p.into_inner()) {
@@ -389,7 +389,7 @@ impl<L: AsLightClient + Send + Sync> Handler for LightSync<L> {
         self.maintain_sync(ctx.as_basic());
     }
 
-    fn on_announcement(&self, ctx: &EventContext, announcement: &Announcement) {
+    fn on_announcement(&self, ctx: &dyn EventContext, announcement: &Announcement) {
         let (last_td, chain_info) = {
             let peers = self.peers.read();
             match peers.get(&ctx.peer()) {
@@ -425,7 +425,7 @@ impl<L: AsLightClient + Send + Sync> Handler for LightSync<L> {
         self.maintain_sync(ctx.as_basic());
     }
 
-    fn on_responses(&self, ctx: &EventContext, req_id: ReqId, responses: &[request::Response]) {
+    fn on_responses(&self, ctx: &dyn EventContext, req_id: ReqId, responses: &[request::Response]) {
         let peer = ctx.peer();
         if !self.peers.read().contains_key(&peer) {
             return;
@@ -469,7 +469,7 @@ impl<L: AsLightClient + Send + Sync> Handler for LightSync<L> {
         self.maintain_sync(ctx.as_basic());
     }
 
-    fn tick(&self, ctx: &BasicContext) {
+    fn tick(&self, ctx: &dyn BasicContext) {
         self.maintain_sync(ctx);
     }
 }
@@ -502,7 +502,7 @@ impl<L: AsLightClient> LightSync<L> {
     }
 
     // handles request dispatch, block import, state machine transitions, and timeouts.
-    fn maintain_sync(&self, ctx: &BasicContext) {
+    fn maintain_sync(&self, ctx: &dyn BasicContext) {
         use ethcore::error::{
             Error as EthcoreError, ErrorKind as EthcoreErrorKind, ImportErrorKind,
         };

ethcore/sync/src/snapshot.rs

@@ -51,7 +51,7 @@ impl Snapshot {
     }
 
     /// Sync the Snapshot completed chunks with the Snapshot Service
-    pub fn initialize(&mut self, snapshot_service: &SnapshotService) {
+    pub fn initialize(&mut self, snapshot_service: &dyn SnapshotService) {
         if self.initialized {
             return;
         }

ethcore/sync/src/sync_io.rs

@@ -37,9 +37,9 @@ pub trait SyncIo {
     /// Send a packet to a peer using specified protocol.
     fn send(&mut self, peer_id: PeerId, packet_id: SyncPacket, data: Vec<u8>) -> Result<(), Error>;
     /// Get the blockchain
-    fn chain(&self) -> &BlockChainClient;
+    fn chain(&self) -> &dyn BlockChainClient;
     /// Get the snapshot service.
-    fn snapshot_service(&self) -> &SnapshotService;
+    fn snapshot_service(&self) -> &dyn SnapshotService;
     /// Returns peer version identifier
     fn peer_version(&self, peer_id: PeerId) -> ClientVersion {
         ClientVersion::from(peer_id.to_string())
@@ -64,18 +64,18 @@ pub trait SyncIo {
 
 /// Wraps `NetworkContext` and the blockchain client
 pub struct NetSyncIo<'s> {
-    network: &'s NetworkContext,
+    network: &'s dyn NetworkContext,
-    chain: &'s BlockChainClient,
+    chain: &'s dyn BlockChainClient,
-    snapshot_service: &'s SnapshotService,
+    snapshot_service: &'s dyn SnapshotService,
     chain_overlay: &'s RwLock<HashMap<BlockNumber, Bytes>>,
 }
 
 impl<'s> NetSyncIo<'s> {
     /// Creates a new instance from the `NetworkContext` and the blockchain client reference.
     pub fn new(
-        network: &'s NetworkContext,
+        network: &'s dyn NetworkContext,
-        chain: &'s BlockChainClient,
+        chain: &'s dyn BlockChainClient,
-        snapshot_service: &'s SnapshotService,
+        snapshot_service: &'s dyn SnapshotService,
         chain_overlay: &'s RwLock<HashMap<BlockNumber, Bytes>>,
     ) -> NetSyncIo<'s> {
         NetSyncIo {
@@ -105,7 +105,7 @@ impl<'s> SyncIo for NetSyncIo<'s> {
             .send_protocol(packet_id.protocol(), peer_id, packet_id.id(), data)
     }
 
-    fn chain(&self) -> &BlockChainClient {
+    fn chain(&self) -> &dyn BlockChainClient {
         self.chain
     }
 
@@ -113,7 +113,7 @@ impl<'s> SyncIo for NetSyncIo<'s> {
         self.chain_overlay
     }
 
-    fn snapshot_service(&self) -> &SnapshotService {
+    fn snapshot_service(&self) -> &dyn SnapshotService {
         self.snapshot_service
     }
 

ethcore/sync/src/tests/consensus.rs

@@ -49,9 +49,9 @@ fn authority_round() {
 
     let chain_id = Spec::new_test_round().chain_id();
     let mut net = TestNet::with_spec(2, SyncConfig::default(), Spec::new_test_round);
-    let io_handler0: Arc<IoHandler<ClientIoMessage>> =
+    let io_handler0: Arc<dyn IoHandler<ClientIoMessage>> =
         Arc::new(TestIoHandler::new(net.peer(0).chain.clone()));
-    let io_handler1: Arc<IoHandler<ClientIoMessage>> =
+    let io_handler1: Arc<dyn IoHandler<ClientIoMessage>> =
         Arc::new(TestIoHandler::new(net.peer(1).chain.clone()));
     // Push transaction to both clients. Only one of them gets lucky to produce a block.
     net.peer(0)

ethcore/sync/src/tests/helpers.rs

@@ -149,7 +149,7 @@ where
         Ok(())
     }
 
-    fn chain(&self) -> &BlockChainClient {
+    fn chain(&self) -> &dyn BlockChainClient {
         &*self.chain
     }
 
@@ -163,7 +163,7 @@ where
         ClientVersion::from(client_id)
     }
 
-    fn snapshot_service(&self) -> &SnapshotService {
+    fn snapshot_service(&self) -> &dyn SnapshotService {
         self.snapshot_service
     }
 

ethcore/sync/src/tests/private.rs

@@ -58,9 +58,9 @@ fn send_private_transaction() {
     let mut net = TestNet::with_spec(2, SyncConfig::default(), seal_spec);
     let client0 = net.peer(0).chain.clone();
     let client1 = net.peer(1).chain.clone();
-    let io_handler0: Arc<IoHandler<ClientIoMessage>> =
+    let io_handler0: Arc<dyn IoHandler<ClientIoMessage>> =
         Arc::new(TestIoHandler::new(net.peer(0).chain.clone()));
-    let io_handler1: Arc<IoHandler<ClientIoMessage>> =
+    let io_handler1: Arc<dyn IoHandler<ClientIoMessage>> =
         Arc::new(TestIoHandler::new(net.peer(1).chain.clone()));
 
     net.peer(0)

ethcore/vm/src/error.rs

@@ -130,5 +130,5 @@ impl fmt::Display for Error {
 pub type Result<T> = ::std::result::Result<T, Error>;
 pub type TrapResult<T, Call, Create> = ::std::result::Result<Result<T>, TrapError<Call, Create>>;
 
-pub type ExecTrapResult<T> = TrapResult<T, Box<ResumeCall>, Box<ResumeCreate>>;
+pub type ExecTrapResult<T> = TrapResult<T, Box<dyn ResumeCall>, Box<dyn ResumeCreate>>;
-pub type ExecTrapError = TrapError<Box<ResumeCall>, Box<ResumeCreate>>;
+pub type ExecTrapError = TrapError<Box<dyn ResumeCall>, Box<dyn ResumeCreate>>;

ethcore/vm/src/lib.rs

@@ -46,17 +46,17 @@ pub trait Exec: Send {
     /// This function should be used to execute transaction.
     /// It returns either an error, a known amount of gas left, or parameters to be used
     /// to compute the final gas left.
-    fn exec(self: Box<Self>, ext: &mut Ext) -> ExecTrapResult<GasLeft>;
+    fn exec(self: Box<Self>, ext: &mut dyn Ext) -> ExecTrapResult<GasLeft>;
 }
 
 /// Resume call interface
 pub trait ResumeCall: Send {
     /// Resume an execution for call, returns back the Vm interface.
-    fn resume_call(self: Box<Self>, result: MessageCallResult) -> Box<Exec>;
+    fn resume_call(self: Box<Self>, result: MessageCallResult) -> Box<dyn Exec>;
 }
 
 /// Resume create interface
 pub trait ResumeCreate: Send {
     /// Resume an execution from create, returns back the Vm interface.
-    fn resume_create(self: Box<Self>, result: ContractCreateResult) -> Box<Exec>;
+    fn resume_create(self: Box<Self>, result: ContractCreateResult) -> Box<dyn Exec>;
 }

ethcore/wasm/run/src/runner.rs

@@ -136,7 +136,7 @@ impl fmt::Display for Fail {
 }
 
 pub fn construct(
-    ext: &mut vm::Ext,
+    ext: &mut dyn vm::Ext,
     source: Vec<u8>,
     arguments: Vec<u8>,
     sender: H160,

ethcore/wasm/src/lib.rs

@@ -96,7 +96,7 @@ enum ExecutionOutcome {
 }
 
 impl WasmInterpreter {
-    pub fn run(self: Box<WasmInterpreter>, ext: &mut vm::Ext) -> vm::Result<GasLeft> {
+    pub fn run(self: Box<WasmInterpreter>, ext: &mut dyn vm::Ext) -> vm::Result<GasLeft> {
         let (module, data) = parser::payload(&self.params, ext.schedule().wasm())?;
 
         let loaded_module =
@@ -204,7 +204,7 @@ impl WasmInterpreter {
 }
 
 impl vm::Exec for WasmInterpreter {
-    fn exec(self: Box<WasmInterpreter>, ext: &mut vm::Ext) -> vm::ExecTrapResult<GasLeft> {
+    fn exec(self: Box<WasmInterpreter>, ext: &mut dyn vm::Ext) -> vm::ExecTrapResult<GasLeft> {
         Ok(self.run(ext))
     }
 }

ethcore/wasm/src/runtime.rs

@@ -33,7 +33,7 @@ pub struct RuntimeContext {
 pub struct Runtime<'a> {
     gas_counter: u64,
     gas_limit: u64,
-    ext: &'a mut vm::Ext,
+    ext: &'a mut dyn vm::Ext,
     context: RuntimeContext,
     memory: MemoryRef,
     args: Vec<u8>,
@@ -149,7 +149,7 @@ type Result<T> = ::std::result::Result<T, Error>;
 impl<'a> Runtime<'a> {
     /// New runtime for wasm contract with specified params
     pub fn with_params(
-        ext: &mut vm::Ext,
+        ext: &mut dyn vm::Ext,
         memory: MemoryRef,
         gas_limit: u64,
         args: Vec<u8>,