diff --git a/account-decoder/src/lib.rs b/account-decoder/src/lib.rs
index 00f0b47543fa4a..3955d0d660f3cb 100644
--- a/account-decoder/src/lib.rs
+++ b/account-decoder/src/lib.rs
@@ -136,16 +136,13 @@ impl UiAccount {
             UiAccountData::Binary(blob, encoding) => match encoding {
                 UiAccountEncoding::Base58 => bs58::decode(blob).into_vec().ok(),
                 UiAccountEncoding::Base64 => base64::decode(blob).ok(),
-                UiAccountEncoding::Base64Zstd => base64::decode(blob)
-                    .ok()
-                    .map(|zstd_data| {
-                        let mut data = vec![];
-                        zstd::stream::read::Decoder::new(zstd_data.as_slice())
-                            .and_then(|mut reader| reader.read_to_end(&mut data))
-                            .map(|_| data)
-                            .ok()
-                    })
-                    .flatten(),
+                UiAccountEncoding::Base64Zstd => base64::decode(blob).ok().and_then(|zstd_data| {
+                    let mut data = vec![];
+                    zstd::stream::read::Decoder::new(zstd_data.as_slice())
+                        .and_then(|mut reader| reader.read_to_end(&mut data))
+                        .map(|_| data)
+                        .ok()
+                }),
                 UiAccountEncoding::Binary | UiAccountEncoding::JsonParsed => None,
             },
         }?;
diff --git a/accounts-cluster-bench/src/main.rs b/accounts-cluster-bench/src/main.rs
index 31b43add99cb88..02c6c6749528a5 100644
--- a/accounts-cluster-bench/src/main.rs
+++ b/accounts-cluster-bench/src/main.rs
@@ -116,7 +116,7 @@ fn make_create_message(
 
     let instructions: Vec<_> = (0..num_instructions)
         .into_iter()
-        .map(|_| {
+        .flat_map(|_| {
             let program_id = if mint.is_some() {
                 inline_spl_token::id()
             } else {
@@ -148,7 +148,6 @@ fn make_create_message(
 
             instructions
         })
-        .flatten()
         .collect();
 
     Message::new(&instructions, Some(&keypair.pubkey()))
diff --git a/clap-utils/src/input_validators.rs b/clap-utils/src/input_validators.rs
index e96de1784e021a..15e8a87a4ccbea 100644
--- a/clap-utils/src/input_validators.rs
+++ b/clap-utils/src/input_validators.rs
@@ -328,7 +328,7 @@ pub fn is_derivation<T>(value: T) -> Result<(), String>
 where
     T: AsRef<str> + Display,
 {
-    let value = value.as_ref().replace("'", "");
+    let value = value.as_ref().replace('\'', "");
     let mut parts = value.split('/');
     let account = parts.next().unwrap();
     account
diff --git a/cli-output/src/cli_output.rs b/cli-output/src/cli_output.rs
index 26a45b760678fd..20651265b94052 100644
--- a/cli-output/src/cli_output.rs
+++ b/cli-output/src/cli_output.rs
@@ -2285,6 +2285,7 @@ impl fmt::Display for CliBlock {
                 let sign = if reward.lamports < 0 { "-" } else { "" };
 
                 total_rewards += reward.lamports;
+                #[allow(clippy::format_in_format_args)]
                 writeln!(
                     f,
                     "  {:<44}  {:^15}  {:>15}  {}  {}",
diff --git a/cli/tests/program.rs b/cli/tests/program.rs
index 54282c8c2efd9a..9e73af7c226776 100644
--- a/cli/tests/program.rs
+++ b/cli/tests/program.rs
@@ -78,7 +78,7 @@ fn test_cli_program_deploy_non_upgradeable() {
     assert_eq!(account0.lamports, minimum_balance_for_rent_exemption);
     assert_eq!(account0.owner, bpf_loader::id());
     assert!(account0.executable);
-    let mut file = File::open(noop_path.to_str().unwrap().to_string()).unwrap();
+    let mut file = File::open(noop_path.to_str().unwrap()).unwrap();
     let mut elf = Vec::new();
     file.read_to_end(&mut elf).unwrap();
     assert_eq!(account0.data, elf);
diff --git a/client/src/mock_sender.rs b/client/src/mock_sender.rs
index 1133e5ad4c7970..2fa8d8642a073b 100644
--- a/client/src/mock_sender.rs
+++ b/client/src/mock_sender.rs
@@ -435,7 +435,7 @@ impl RpcSender for MockSender {
                 value: vec![Value::Null, Value::Null]
             })?,
             "getProgramAccounts" => {
-                let pubkey = Pubkey::from_str(&PUBKEY.to_string()).unwrap();
+                let pubkey = Pubkey::from_str(PUBKEY).unwrap();
                 let account = Account {
                     lamports: 1_000_000,
                     data: vec![],
diff --git a/client/src/perf_utils.rs b/client/src/perf_utils.rs
index a22451b4b74b4b..d3f42d1db817f7 100644
--- a/client/src/perf_utils.rs
+++ b/client/src/perf_utils.rs
@@ -43,18 +43,16 @@ pub fn sample_txs<T>(
         total_elapsed = start_time.elapsed();
         let elapsed = now.elapsed();
         now = Instant::now();
-        let mut txs;
-        match client.get_transaction_count_with_commitment(CommitmentConfig::processed()) {
-            Err(e) => {
-                // ThinClient with multiple options should pick a better one now.
-                info!("Couldn't get transaction count {:?}", e);
-                sleep(Duration::from_secs(sample_period));
-                continue;
-            }
-            Ok(tx_count) => {
-                txs = tx_count;
-            }
-        }
+        let mut txs =
+            match client.get_transaction_count_with_commitment(CommitmentConfig::processed()) {
+                Err(e) => {
+                    // ThinClient with multiple options should pick a better one now.
+                    info!("Couldn't get transaction count {:?}", e);
+                    sleep(Duration::from_secs(sample_period));
+                    continue;
+                }
+                Ok(tx_count) => tx_count,
+            };
 
         if txs < last_txs {
             info!("Expected txs({}) >= last_txs({})", txs, last_txs);
diff --git a/core/src/banking_stage.rs b/core/src/banking_stage.rs
index d21dd682256d7c..7c407571e6f712 100644
--- a/core/src/banking_stage.rs
+++ b/core/src/banking_stage.rs
@@ -490,79 +490,82 @@ impl BankingStage {
         let mut proc_start = Measure::start("consume_buffered_process");
         let mut reached_end_of_slot = None;
 
-        RetainMut::retain_mut(buffered_packet_batches, |buffered_packet_batch_and_offsets| {
-            let (packet_batch, ref mut original_unprocessed_indexes, _forwarded) =
-                buffered_packet_batch_and_offsets;
-            if let Some((next_leader, bank)) = &reached_end_of_slot {
-                // We've hit the end of this slot, no need to perform more processing,
-                // just filter the remaining packets for the invalid (e.g. too old) ones
-                let new_unprocessed_indexes = Self::filter_unprocessed_packets(
-                    bank,
-                    packet_batch,
-                    original_unprocessed_indexes,
-                    my_pubkey,
-                    *next_leader,
-                    banking_stage_stats,
-                );
-                Self::update_buffered_packets_with_new_unprocessed(
-                    original_unprocessed_indexes,
-                    new_unprocessed_indexes,
-                )
-            } else {
-                let bank_start = poh_recorder.lock().unwrap().bank_start();
-                if let Some(BankStart {
-                    working_bank,
-                    bank_creation_time,
-                }) = bank_start
-                {
-                    let (processed, verified_txs_len, new_unprocessed_indexes) =
-                        Self::process_packets_transactions(
-                            &working_bank,
-                            &bank_creation_time,
-                            recorder,
-                            packet_batch,
-                            original_unprocessed_indexes.to_owned(),
-                            transaction_status_sender.clone(),
-                            gossip_vote_sender,
-                            banking_stage_stats,
-                            qos_service,
-                        );
-                    if processed < verified_txs_len
-                        || !Bank::should_bank_still_be_processing_txs(
-                            &bank_creation_time,
-                            max_tx_ingestion_ns,
-                        )
+        RetainMut::retain_mut(
+            buffered_packet_batches,
+            |buffered_packet_batch_and_offsets| {
+                let (packet_batch, ref mut original_unprocessed_indexes, _forwarded) =
+                    buffered_packet_batch_and_offsets;
+                if let Some((next_leader, bank)) = &reached_end_of_slot {
+                    // We've hit the end of this slot, no need to perform more processing,
+                    // just filter the remaining packets for the invalid (e.g. too old) ones
+                    let new_unprocessed_indexes = Self::filter_unprocessed_packets(
+                        bank,
+                        packet_batch,
+                        original_unprocessed_indexes,
+                        my_pubkey,
+                        *next_leader,
+                        banking_stage_stats,
+                    );
+                    Self::update_buffered_packets_with_new_unprocessed(
+                        original_unprocessed_indexes,
+                        new_unprocessed_indexes,
+                    )
+                } else {
+                    let bank_start = poh_recorder.lock().unwrap().bank_start();
+                    if let Some(BankStart {
+                        working_bank,
+                        bank_creation_time,
+                    }) = bank_start
                     {
-                        reached_end_of_slot = Some((
-                            poh_recorder.lock().unwrap().next_slot_leader(),
-                            working_bank,
+                        let (processed, verified_txs_len, new_unprocessed_indexes) =
+                            Self::process_packets_transactions(
+                                &working_bank,
+                                &bank_creation_time,
+                                recorder,
+                                packet_batch,
+                                original_unprocessed_indexes.to_owned(),
+                                transaction_status_sender.clone(),
+                                gossip_vote_sender,
+                                banking_stage_stats,
+                                qos_service,
+                            );
+                        if processed < verified_txs_len
+                            || !Bank::should_bank_still_be_processing_txs(
+                                &bank_creation_time,
+                                max_tx_ingestion_ns,
+                            )
+                        {
+                            reached_end_of_slot = Some((
+                                poh_recorder.lock().unwrap().next_slot_leader(),
+                                working_bank,
+                            ));
+                        }
+                        new_tx_count += processed;
+
+                        // Out of the buffered packets just retried, collect any still unprocessed
+                        // transactions in this batch for forwarding
+                        rebuffered_packet_count += new_unprocessed_indexes.len();
+                        let has_more_unprocessed_transactions =
+                            Self::update_buffered_packets_with_new_unprocessed(
+                                original_unprocessed_indexes,
+                                new_unprocessed_indexes,
+                            );
+                        if let Some(test_fn) = &test_fn {
+                            test_fn();
+                        }
+                        has_more_unprocessed_transactions
+                    } else {
+                        rebuffered_packet_count += original_unprocessed_indexes.len();
+                        // `original_unprocessed_indexes` must have remaining packets to process
+                        // if not yet processed.
+                        assert!(Self::packet_has_more_unprocessed_transactions(
+                            original_unprocessed_indexes
                         ));
+                        true
                     }
-                    new_tx_count += processed;
-
-                    // Out of the buffered packets just retried, collect any still unprocessed
-                    // transactions in this batch for forwarding
-                    rebuffered_packet_count += new_unprocessed_indexes.len();
-                    let has_more_unprocessed_transactions =
-                        Self::update_buffered_packets_with_new_unprocessed(
-                            original_unprocessed_indexes,
-                            new_unprocessed_indexes,
-                        );
-                    if let Some(test_fn) = &test_fn {
-                        test_fn();
-                    }
-                    has_more_unprocessed_transactions
-                } else {
-                    rebuffered_packet_count += original_unprocessed_indexes.len();
-                    // `original_unprocessed_indexes` must have remaining packets to process
-                    // if not yet processed.
-                    assert!(Self::packet_has_more_unprocessed_transactions(
-                        original_unprocessed_indexes
-                    ));
-                    true
                 }
-            }
-        });
+            },
+        );
 
         proc_start.stop();
 
diff --git a/core/src/replay_stage.rs b/core/src/replay_stage.rs
index 6dd935d3e6ad13..084266ef1c1503 100644
--- a/core/src/replay_stage.rs
+++ b/core/src/replay_stage.rs
@@ -4327,9 +4327,9 @@ pub mod tests {
         for i in 0..std::cmp::max(new_vote_pubkeys.len(), new_node_pubkeys.len()) {
             propagated_stats.is_propagated = false;
             let len = std::cmp::min(i, new_vote_pubkeys.len());
-            let mut voted_pubkeys = new_vote_pubkeys[..len].iter().copied().collect();
+            let mut voted_pubkeys = new_vote_pubkeys[..len].to_vec();
             let len = std::cmp::min(i, new_node_pubkeys.len());
-            let mut node_pubkeys = new_node_pubkeys[..len].iter().copied().collect();
+            let mut node_pubkeys = new_node_pubkeys[..len].to_vec();
             let did_newly_reach_threshold =
                 ReplayStage::update_slot_propagated_threshold_from_votes(
                     &mut voted_pubkeys,
diff --git a/genesis/src/main.rs b/genesis/src/main.rs
index 06c9e373b979d3..61e9c513c2c46c 100644
--- a/genesis/src/main.rs
+++ b/genesis/src/main.rs
@@ -60,7 +60,7 @@ fn pubkey_from_str(key_str: &str) -> Result<Pubkey, Box<dyn error::Error>> {
 
 pub fn load_genesis_accounts(file: &str, genesis_config: &mut GenesisConfig) -> io::Result<u64> {
     let mut lamports = 0;
-    let accounts_file = File::open(file.to_string())?;
+    let accounts_file = File::open(file)?;
 
     let genesis_accounts: HashMap<String, Base64Account> =
         serde_yaml::from_reader(accounts_file)
diff --git a/gossip/src/cluster_info.rs b/gossip/src/cluster_info.rs
index b266311f7ab3cd..eb88313d0b2e63 100644
--- a/gossip/src/cluster_info.rs
+++ b/gossip/src/cluster_info.rs
@@ -708,9 +708,9 @@ impl ClusterInfo {
                 Some(format!(
                     "{:15} {:2}| {:5} | {:44} |{:^9}| {:5}| {:5}| {}\n",
                     rpc_addr.to_string(),
-                    if node.id == my_pubkey { "me" } else { "" }.to_string(),
+                    if node.id == my_pubkey { "me" } else { "" },
                     now.saturating_sub(last_updated),
-                    node.id.to_string(),
+                    node.id,
                     if let Some(node_version) = node_version {
                         node_version.to_string()
                     } else {
@@ -778,9 +778,9 @@ impl ClusterInfo {
                         } else {
                             "none".to_string()
                         },
-                        if node.id == my_pubkey { "me" } else { "" }.to_string(),
+                        if node.id == my_pubkey { "me" } else { "" },
                         now.saturating_sub(last_updated),
-                        node.id.to_string(),
+                        node.id,
                         if let Some(node_version) = node_version {
                             node_version.to_string()
                         } else {
diff --git a/install/src/config.rs b/install/src/config.rs
index 8ced2420df88aa..addb97f3d86476 100644
--- a/install/src/config.rs
+++ b/install/src/config.rs
@@ -45,7 +45,7 @@ impl Config {
     }
 
     fn _load(config_file: &str) -> Result<Self, io::Error> {
-        let file = File::open(config_file.to_string())?;
+        let file = File::open(config_file)?;
         let config = serde_yaml::from_reader(file)
             .map_err(|err| io::Error::new(io::ErrorKind::Other, format!("{:?}", err)))?;
         Ok(config)
diff --git a/ledger/src/blockstore.rs b/ledger/src/blockstore.rs
index ec09242abe2b43..f02ab9f3e61e43 100644
--- a/ledger/src/blockstore.rs
+++ b/ledger/src/blockstore.rs
@@ -1890,10 +1890,7 @@ impl Blockstore {
     }
 
     pub fn get_block_time(&self, slot: Slot) -> Result<Option<UnixTimestamp>> {
-        datapoint_info!(
-            "blockstore-rpc-api",
-            ("method", "get_block_time".to_string(), String)
-        );
+        datapoint_info!("blockstore-rpc-api", ("method", "get_block_time", String));
         let _lock = self.check_lowest_cleanup_slot(slot)?;
         self.blocktime_cf.get(slot)
     }
@@ -1903,10 +1900,7 @@ impl Blockstore {
     }
 
     pub fn get_block_height(&self, slot: Slot) -> Result<Option<u64>> {
-        datapoint_info!(
-            "blockstore-rpc-api",
-            ("method", "get_block_height".to_string(), String)
-        );
+        datapoint_info!("blockstore-rpc-api", ("method", "get_block_height", String));
         let _lock = self.check_lowest_cleanup_slot(slot)?;
         self.block_height_cf.get(slot)
     }
@@ -1925,10 +1919,7 @@ impl Blockstore {
         slot: Slot,
         require_previous_blockhash: bool,
     ) -> Result<VersionedConfirmedBlock> {
-        datapoint_info!(
-            "blockstore-rpc-api",
-            ("method", "get_rooted_block".to_string(), String)
-        );
+        datapoint_info!("blockstore-rpc-api", ("method", "get_rooted_block", String));
         let _lock = self.check_lowest_cleanup_slot(slot)?;
 
         if self.is_root(slot) {
@@ -2256,11 +2247,7 @@ impl Blockstore {
     ) -> Result<Option<(Slot, TransactionStatusMeta)>> {
         datapoint_info!(
             "blockstore-rpc-api",
-            (
-                "method",
-                "get_rooted_transaction_status".to_string(),
-                String
-            )
+            ("method", "get_rooted_transaction_status", String)
         );
         self.get_transaction_status(signature, &[])
     }
@@ -2273,7 +2260,7 @@ impl Blockstore {
     ) -> Result<Option<(Slot, TransactionStatusMeta)>> {
         datapoint_info!(
             "blockstore-rpc-api",
-            ("method", "get_transaction_status".to_string(), String)
+            ("method", "get_transaction_status", String)
         );
         self.get_transaction_status_with_counter(signature, confirmed_unrooted_slots)
             .map(|(status, _)| status)
@@ -2286,7 +2273,7 @@ impl Blockstore {
     ) -> Result<Option<VersionedConfirmedTransactionWithStatusMeta>> {
         datapoint_info!(
             "blockstore-rpc-api",
-            ("method", "get_rooted_transaction".to_string(), String)
+            ("method", "get_rooted_transaction", String)
         );
         self.get_transaction_with_status(signature, &[])
     }
@@ -2299,7 +2286,7 @@ impl Blockstore {
     ) -> Result<Option<VersionedConfirmedTransactionWithStatusMeta>> {
         datapoint_info!(
             "blockstore-rpc-api",
-            ("method", "get_complete_transaction".to_string(), String)
+            ("method", "get_complete_transaction", String)
         );
         let last_root = self.last_root();
         let confirmed_unrooted_slots: Vec<_> =
@@ -2442,11 +2429,7 @@ impl Blockstore {
     ) -> Result<Vec<Signature>> {
         datapoint_info!(
             "blockstore-rpc-api",
-            (
-                "method",
-                "get_confirmed_signatures_for_address".to_string(),
-                String
-            )
+            ("method", "get_confirmed_signatures_for_address", String)
         );
         self.find_address_signatures(pubkey, start_slot, end_slot)
             .map(|signatures| signatures.iter().map(|(_, signature)| *signature).collect())
@@ -2491,11 +2474,7 @@ impl Blockstore {
     ) -> Result<SignatureInfosForAddress> {
         datapoint_info!(
             "blockstore-rpc-api",
-            (
-                "method",
-                "get_confirmed_signatures_for_address2".to_string(),
-                String
-            )
+            ("method", "get_confirmed_signatures_for_address2", String)
         );
         let last_root = self.last_root();
         let confirmed_unrooted_slots: Vec<_> = AncestorIterator::new_inclusive(highest_slot, self)
@@ -3411,7 +3390,7 @@ fn send_signals(
                     "blockstore_error",
                     (
                         "error",
-                        "Unable to send newly completed slot because channel is full".to_string(),
+                        "Unable to send newly completed slot because channel is full",
                         String
                     ),
                 );
diff --git a/ledger/src/shred.rs b/ledger/src/shred.rs
index 05168f86c6133f..3510c6fe7eb8fd 100644
--- a/ledger/src/shred.rs
+++ b/ledger/src/shred.rs
@@ -1152,30 +1152,26 @@ pub fn get_shred_slot_index_type(
         return None;
     }
 
-    let index;
-    match limited_deserialize::<u32>(&p.data[index_start..index_end]) {
-        Ok(x) => index = x,
+    let index = match limited_deserialize::<u32>(&p.data[index_start..index_end]) {
+        Ok(x) => x,
         Err(_e) => {
             stats.index_bad_deserialize += 1;
             return None;
         }
-    }
+    };
 
     if index >= MAX_DATA_SHREDS_PER_SLOT as u32 {
         stats.index_out_of_bounds += 1;
         return None;
     }
 
-    let slot;
-    match limited_deserialize::<Slot>(&p.data[slot_start..slot_end]) {
-        Ok(x) => {
-            slot = x;
-        }
+    let slot = match limited_deserialize::<Slot>(&p.data[slot_start..slot_end]) {
+        Ok(x) => x,
         Err(_e) => {
             stats.slot_bad_deserialize += 1;
             return None;
         }
-    }
+    };
 
     let shred_type = match ShredType::from_u8(p.data[OFFSET_OF_SHRED_TYPE]) {
         None => {
diff --git a/local-cluster/tests/local_cluster.rs b/local-cluster/tests/local_cluster.rs
index 35e77bb4fb1d0d..bb552d3c50267c 100644
--- a/local-cluster/tests/local_cluster.rs
+++ b/local-cluster/tests/local_cluster.rs
@@ -2591,7 +2591,7 @@ fn test_votes_land_in_fork_during_long_partition() {
                 // Should finish faster than if the cluster were relying on replay vote
                 // refreshing to refresh the vote on blockhash expiration for the vote
                 // transaction.
-                !(start.elapsed() > Duration::from_millis(max_wait)),
+                start.elapsed() <= Duration::from_millis(max_wait),
                 "Went too long {} ms without a root",
                 max_wait,
             );
diff --git a/metrics/src/datapoint.rs b/metrics/src/datapoint.rs
index c25f3a5e707400..1b5112ceb0c3fc 100644
--- a/metrics/src/datapoint.rs
+++ b/metrics/src/datapoint.rs
@@ -18,7 +18,7 @@ impl DataPoint {
 
     pub fn add_field_str(&mut self, name: &'static str, value: &str) -> &mut Self {
         self.fields
-            .push((name, format!("\"{}\"", value.replace("\"", "\\\""))));
+            .push((name, format!("\"{}\"", value.replace('\"', "\\\""))));
         self
     }
 
@@ -151,7 +151,7 @@ macro_rules! datapoint_trace {
 mod test {
     #[test]
     fn test_datapoint() {
-        datapoint_debug!("name", ("field name", "test".to_string(), String));
+        datapoint_debug!("name", ("field name", "test", String));
         datapoint_info!("name", ("field name", 12.34_f64, f64));
         datapoint_trace!("name", ("field name", true, bool));
         datapoint_warn!("name", ("field name", 1, i64));
@@ -180,7 +180,7 @@ mod test {
         let point = create_datapoint!(
             @point "name",
             ("i64", 1, i64),
-            ("String", "string space string".to_string(), String),
+            ("String", "string space string", String),
             ("f64", 12.34_f64, f64),
             ("bool", true, bool)
         );
diff --git a/remote-wallet/src/ledger.rs b/remote-wallet/src/ledger.rs
index cb72f3bbd8323c..c5a689d50a9522 100644
--- a/remote-wallet/src/ledger.rs
+++ b/remote-wallet/src/ledger.rs
@@ -373,7 +373,7 @@ impl RemoteWallet<hidapi::DeviceInfo> for LedgerWallet {
             .product_string()
             .unwrap_or("Unknown")
             .to_lowercase()
-            .replace(" ", "-");
+            .replace(' ', "-");
         let serial = dev_info.serial_number().unwrap_or("Unknown").to_string();
         let host_device_path = dev_info.path().to_string_lossy().to_string();
         let version = self.get_firmware_version()?;
diff --git a/rpc/src/rpc.rs b/rpc/src/rpc.rs
index 77b5db5bbcc6bf..6c8ad507908245 100644
--- a/rpc/src/rpc.rs
+++ b/rpc/src/rpc.rs
@@ -6344,7 +6344,7 @@ pub mod tests {
         assert_eq!(verify_pubkey(&pubkey.to_string()).unwrap(), pubkey);
         let bad_pubkey = "a1b2c3d4";
         assert_eq!(
-            verify_pubkey(&bad_pubkey.to_string()),
+            verify_pubkey(bad_pubkey),
             Err(Error::invalid_params("Invalid param: WrongSize"))
         );
     }
@@ -6363,7 +6363,7 @@ pub mod tests {
         );
         let bad_signature = "a1b2c3d4";
         assert_eq!(
-            verify_signature(&bad_signature.to_string()),
+            verify_signature(bad_signature),
             Err(Error::invalid_params("Invalid param: WrongSize"))
         );
     }
diff --git a/rpc/src/rpc_subscriptions.rs b/rpc/src/rpc_subscriptions.rs
index 26b159e76c5493..617047b4ab66ea 100644
--- a/rpc/src/rpc_subscriptions.rs
+++ b/rpc/src/rpc_subscriptions.rs
@@ -1097,7 +1097,7 @@ impl RpcSubscriptions {
             inc_new_counter_info!("rpc-subscription-notify-bank-or-gossip", total_notified);
             datapoint_info!(
                 "rpc_subscriptions",
-                ("source", source.to_string(), String),
+                ("source", source, String),
                 (
                     "num_account_subscriptions",
                     num_accounts_found.load(Ordering::Relaxed),
diff --git a/runtime/benches/bank.rs b/runtime/benches/bank.rs
index cacb43e45bb39c..d8de9bd155252d 100644
--- a/runtime/benches/bank.rs
+++ b/runtime/benches/bank.rs
@@ -90,7 +90,7 @@ fn sync_bencher(bank: &Arc<Bank>, _bank_client: &BankClient, transactions: &[Tra
 }
 
 fn async_bencher(bank: &Arc<Bank>, bank_client: &BankClient, transactions: &[Transaction]) {
-    for transaction in transactions.to_owned() {
+    for transaction in transactions.iter().cloned() {
         bank_client.async_send_transaction(transaction).unwrap();
     }
     for _ in 0..1_000_000_000_u64 {
diff --git a/runtime/src/accounts_db.rs b/runtime/src/accounts_db.rs
index 47e4225aa4c5b8..46642a016f765f 100644
--- a/runtime/src/accounts_db.rs
+++ b/runtime/src/accounts_db.rs
@@ -4207,16 +4207,15 @@ impl AccountsDb {
             .fetch_add(scan_storages_elasped.as_us(), Ordering::Relaxed);
 
         let mut purge_accounts_index_elapsed = Measure::start("purge_accounts_index_elapsed");
-        let reclaims;
-        match scan_result {
+        let reclaims = match scan_result {
             ScanStorageResult::Cached(_) => {
                 panic!("Should not see cached keys in this `else` branch, since we checked this slot did not exist in the cache above");
             }
             ScanStorageResult::Stored(stored_keys) => {
                 // Purge this slot from the accounts index
-                reclaims = self.purge_keys_exact(stored_keys.lock().unwrap().iter());
+                self.purge_keys_exact(stored_keys.lock().unwrap().iter())
             }
-        }
+        };
         purge_accounts_index_elapsed.stop();
         purge_stats
             .purge_accounts_index_elapsed
@@ -5104,12 +5103,11 @@ impl AccountsDb {
             .accounts_index
             .account_maps
             .iter()
-            .map(|map| {
+            .flat_map(|map| {
                 let mut keys = map.read().unwrap().keys();
                 keys.sort_unstable(); // hashmap is not ordered, but bins are relative to each other
                 keys
             })
-            .flatten()
             .collect();
         collect.stop();
 
diff --git a/runtime/src/accounts_hash.rs b/runtime/src/accounts_hash.rs
index 8195963645c08d..e16428405a315e 100644
--- a/runtime/src/accounts_hash.rs
+++ b/runtime/src/accounts_hash.rs
@@ -1154,7 +1154,7 @@ pub mod tests {
         let sorted2 = chunk.clone();
 
         let mut with_left_over = vec![left_over_1];
-        with_left_over.extend(sorted2[0..plus1 - 2].to_vec().into_iter().map(|i| i.hash));
+        with_left_over.extend(sorted2[0..plus1 - 2].iter().cloned().map(|i| i.hash));
         let expected_hash2 = AccountsHash::compute_merkle_root(
             with_left_over[0..target_fanout]
                 .iter()
diff --git a/runtime/src/bank.rs b/runtime/src/bank.rs
index da1cf24d2c8dc0..cb263db03d1fd2 100644
--- a/runtime/src/bank.rs
+++ b/runtime/src/bank.rs
@@ -12891,8 +12891,7 @@ pub(crate) mod tests {
         assert!(cache.get(&key4).is_some());
         let num_retained = [&key1, &key2, &key3]
             .iter()
-            .map(|key| cache.get(key))
-            .flatten()
+            .filter_map(|key| cache.get(key))
             .count();
         assert_eq!(num_retained, 2);
 
@@ -12903,8 +12902,7 @@ pub(crate) mod tests {
         assert!(cache.get(&key3).is_some());
         let num_retained = [&key1, &key2, &key4]
             .iter()
-            .map(|key| cache.get(key))
-            .flatten()
+            .filter_map(|key| cache.get(key))
             .count();
         assert_eq!(num_retained, 2);
     }
@@ -12937,8 +12935,7 @@ pub(crate) mod tests {
         assert!(cache.get(&key4).is_some());
         let num_retained = [&key1, &key2, &key3]
             .iter()
-            .map(|key| cache.get(key))
-            .flatten()
+            .filter_map(|key| cache.get(key))
             .count();
         assert_eq!(num_retained, 2);
 
@@ -12948,8 +12945,7 @@ pub(crate) mod tests {
         assert!(cache.get(&key3).is_some());
         let num_retained = [&key2, &key4]
             .iter()
-            .map(|key| cache.get(key))
-            .flatten()
+            .filter_map(|key| cache.get(key))
             .count();
         assert_eq!(num_retained, 1);
 
diff --git a/runtime/src/bank_client.rs b/runtime/src/bank_client.rs
index 554fe59d46d4c6..dfe2de40e02928 100644
--- a/runtime/src/bank_client.rs
+++ b/runtime/src/bank_client.rs
@@ -315,8 +315,7 @@ impl SyncClient for BankClient {
     fn get_fee_for_message(&self, message: &Message) -> Result<u64> {
         SanitizedMessage::try_from(message.clone())
             .ok()
-            .map(|sanitized_message| self.bank.get_fee_for_message(&sanitized_message))
-            .flatten()
+            .and_then(|sanitized_message| self.bank.get_fee_for_message(&sanitized_message))
             .ok_or_else(|| {
                 TransportError::IoError(io::Error::new(
                     io::ErrorKind::Other,
diff --git a/runtime/src/bank_forks.rs b/runtime/src/bank_forks.rs
index 66f75ad5922439..d6c123abac9a72 100644
--- a/runtime/src/bank_forks.rs
+++ b/runtime/src/bank_forks.rs
@@ -574,7 +574,7 @@ mod tests {
         let bank = Bank::new_from_parent(&bank0, &Pubkey::default(), 2);
         bank_forks.insert(bank);
         let descendants = bank_forks.descendants();
-        let children: HashSet<u64> = [1u64, 2u64].to_vec().into_iter().collect();
+        let children: HashSet<u64> = [1u64, 2u64].iter().copied().collect();
         assert_eq!(children, *descendants.get(&0).unwrap());
         assert!(descendants[&1].is_empty());
         assert!(descendants[&2].is_empty());
diff --git a/runtime/src/in_mem_accounts_index.rs b/runtime/src/in_mem_accounts_index.rs
index a296000efe2e52..08681e6dba8a66 100644
--- a/runtime/src/in_mem_accounts_index.rs
+++ b/runtime/src/in_mem_accounts_index.rs
@@ -671,7 +671,7 @@ impl<T: IndexValue> InMemAccountsIndex<T> {
     where
         R: RangeBounds<Pubkey>,
     {
-        assert!(!(only_add_if_already_held && !start_holding));
+        assert!(!only_add_if_already_held || start_holding);
         let start = match range.start_bound() {
             Bound::Included(bound) | Bound::Excluded(bound) => *bound,
             Bound::Unbounded => Pubkey::new(&[0; 32]),
diff --git a/sdk/cargo-build-bpf/src/main.rs b/sdk/cargo-build-bpf/src/main.rs
index d2559777d90e96..49b28d7b9c8270 100644
--- a/sdk/cargo-build-bpf/src/main.rs
+++ b/sdk/cargo-build-bpf/src/main.rs
@@ -418,7 +418,7 @@ fn build_bpf_package(config: &Config, target_directory: &Path, package: &cargo_m
                 );
                 None
             }
-            1 => Some(cdylib_targets[0].replace("-", "_")),
+            1 => Some(cdylib_targets[0].replace('-', "_")),
             _ => {
                 eprintln!(
                     "{} crate contains multiple cdylib targets: {:?}",
@@ -821,7 +821,7 @@ fn main() {
         dump: matches.is_present("dump"),
         features: values_t!(matches, "features", String)
             .ok()
-            .unwrap_or_else(Vec::new),
+            .unwrap_or_default(),
         generate_child_script_on_failure: matches.is_present("generate_child_script_on_failure"),
         no_default_features: matches.is_present("no_default_features"),
         offline: matches.is_present("offline"),
diff --git a/sdk/cargo-test-bpf/src/main.rs b/sdk/cargo-test-bpf/src/main.rs
index e43bfa39a00128..b8b0b921b04c9c 100644
--- a/sdk/cargo-test-bpf/src/main.rs
+++ b/sdk/cargo-test-bpf/src/main.rs
@@ -309,10 +309,10 @@ fn main() {
         bpf_out_dir: value_t!(matches, "bpf_out_dir", String).ok(),
         extra_cargo_test_args: values_t!(matches, "extra_cargo_test_args", String)
             .ok()
-            .unwrap_or_else(Vec::new),
+            .unwrap_or_default(),
         features: values_t!(matches, "features", String)
             .ok()
-            .unwrap_or_else(Vec::new),
+            .unwrap_or_default(),
         generate_child_script_on_failure: matches.is_present("generate_child_script_on_failure"),
         test_name: value_t!(matches, "test", String).ok(),
         no_default_features: matches.is_present("no_default_features"),
diff --git a/sdk/program/src/borsh.rs b/sdk/program/src/borsh.rs
index d7d278234b4add..aa1a978954f029 100644
--- a/sdk/program/src/borsh.rs
+++ b/sdk/program/src/borsh.rs
@@ -188,7 +188,7 @@ mod tests {
     fn packed_len() {
         assert_eq!(
             get_packed_len::<TestEnum>(),
-            size_of::<u8>() + size_of::<u64>() + size_of::<u8>() * 8
+            size_of::<u8>() + size_of::<u64>() + u8::BITS as usize
         );
         assert_eq!(
             get_packed_len::<TestStruct>(),
diff --git a/sdk/src/ed25519_instruction.rs b/sdk/src/ed25519_instruction.rs
index 801345f1f43200..123c56a6ee3c16 100644
--- a/sdk/src/ed25519_instruction.rs
+++ b/sdk/src/ed25519_instruction.rs
@@ -161,7 +161,7 @@ fn get_data_slice<'a>(
         if signature_index >= instruction_datas.len() {
             return Err(PrecompileError::InvalidDataOffsets);
         }
-        &instruction_datas[signature_index]
+        instruction_datas[signature_index]
     };
 
     let start = offset_start as usize;
diff --git a/sdk/src/pubkey.rs b/sdk/src/pubkey.rs
index 4b343ae629c023..b28672b7f36226 100644
--- a/sdk/src/pubkey.rs
+++ b/sdk/src/pubkey.rs
@@ -24,7 +24,7 @@ pub fn write_pubkey_file(outfile: &str, pubkey: Pubkey) -> Result<(), Box<dyn st
 
 #[cfg(feature = "full")]
 pub fn read_pubkey_file(infile: &str) -> Result<Pubkey, Box<dyn std::error::Error>> {
-    let f = std::fs::File::open(infile.to_string())?;
+    let f = std::fs::File::open(infile)?;
     let printable: String = serde_json::from_reader(f)?;
 
     use std::str::FromStr;
diff --git a/streamer/src/streamer.rs b/streamer/src/streamer.rs
index def53c6eb96036..4ac711ced3cabd 100644
--- a/streamer/src/streamer.rs
+++ b/streamer/src/streamer.rs
@@ -104,7 +104,7 @@ pub fn receiver(
     use_pinned_memory: bool,
 ) -> JoinHandle<()> {
     let res = sock.set_read_timeout(Some(Duration::new(1, 0)));
-    assert!(!res.is_err(), "streamer::receiver set_read_timeout error");
+    assert!(res.is_ok(), "streamer::receiver set_read_timeout error");
     let exit = exit.clone();
     Builder::new()
         .name("solana-receiver".to_string())
diff --git a/transaction-status/src/lib.rs b/transaction-status/src/lib.rs
index c69ffd66ff9d2e..25c54fb7e99818 100644
--- a/transaction-status/src/lib.rs
+++ b/transaction-status/src/lib.rs
@@ -577,8 +577,7 @@ impl VersionedTransactionWithStatusMeta {
         let dynamic_keys_iter = self
             .meta
             .iter()
-            .map(|meta| meta.loaded_addresses.ordered_iter())
-            .flatten();
+            .flat_map(|meta| meta.loaded_addresses.ordered_iter());
 
         static_keys_iter.chain(dynamic_keys_iter)
     }
diff --git a/upload-perf/src/upload-perf.rs b/upload-perf/src/upload-perf.rs
index 9d7a418d525f8f..cb349c94b2619f 100644
--- a/upload-perf/src/upload-perf.rs
+++ b/upload-perf/src/upload-perf.rs
@@ -61,7 +61,7 @@ fn main() {
                 let name = v["name"].as_str().unwrap().trim_matches('\"').to_string();
 
                 if last_commit.is_none() {
-                    last_commit = get_last_metrics(&"commit".to_string(), &db, &name, branch).ok();
+                    last_commit = get_last_metrics("commit", &db, &name, branch).ok();
                 }
 
                 let median: i64 = v["median"].to_string().parse().unwrap();
@@ -79,9 +79,9 @@ fn main() {
                 */
 
                 let last_median =
-                    get_last_metrics(&"median".to_string(), &db, &name, branch).unwrap_or_default();
-                let last_deviation = get_last_metrics(&"deviation".to_string(), &db, &name, branch)
-                    .unwrap_or_default();
+                    get_last_metrics("median", &db, &name, branch).unwrap_or_default();
+                let last_deviation =
+                    get_last_metrics("deviation", &db, &name, branch).unwrap_or_default();
 
                 results.insert(name, (median, deviation, last_median, last_deviation));
             }
diff --git a/validator/src/dashboard.rs b/validator/src/dashboard.rs
index 436c4a1ea30099..4626f7fc978024 100644
--- a/validator/src/dashboard.rs
+++ b/validator/src/dashboard.rs
@@ -169,10 +169,9 @@ impl Dashboard {
                                 .unwrap_or_else(|| '-'.to_string()),
                             snapshot_slot_info
                                 .as_ref()
-                                .map(|snapshot_slot_info| snapshot_slot_info
+                                .and_then(|snapshot_slot_info| snapshot_slot_info
                                     .incremental
                                     .map(|incremental| incremental.to_string()))
-                                .flatten()
                                 .unwrap_or_else(|| '-'.to_string()),
                             transaction_count,
                             identity_balance
diff --git a/validator/src/main.rs b/validator/src/main.rs
index 0f5b9ebe66d72f..6231d2e27e4c3e 100644
--- a/validator/src/main.rs
+++ b/validator/src/main.rs
@@ -334,10 +334,9 @@ fn wait_for_restart_window(
                         .unwrap_or_else(|| '-'.to_string()),
                     snapshot_slot_info
                         .as_ref()
-                        .map(|snapshot_slot_info| snapshot_slot_info
+                        .and_then(|snapshot_slot_info| snapshot_slot_info
                             .incremental
                             .map(|incremental| incremental.to_string()))
-                        .flatten()
                         .unwrap_or_else(|| '-'.to_string()),
                 )
             },
diff --git a/watchtower/src/main.rs b/watchtower/src/main.rs
index b168bda9e5ad04..7ea796dfea65c1 100644
--- a/watchtower/src/main.rs
+++ b/watchtower/src/main.rs
@@ -152,7 +152,7 @@ fn get_config() -> Config {
     let json_rpc_url =
         value_t!(matches, "json_rpc_url", String).unwrap_or_else(|_| config.json_rpc_url.clone());
     let validator_identity_pubkeys: Vec<_> = pubkeys_of(&matches, "validator_identities")
-        .unwrap_or_else(Vec::new)
+        .unwrap_or_default()
         .into_iter()
         .collect();