Fix vec![] usage

src/daemon.rs

@@ -127,7 +127,7 @@ impl Daemon {
             .iter()
             .map(|params| json!({"method": method, "params": params}))
             .collect();
-        let mut result = Vec::new();
+        let mut result = vec![];
         for reply in self.call_jsonrpc(&reqs)
             .chain_err(|| format!("RPC failed: {}", reqs))?
             .as_array_mut()
@@ -164,7 +164,7 @@ impl Daemon {
             Ok(deserialize(&header_bytes)
                 .chain_err(|| format!("failed to parse blockheader {}", header_hex))?)
         }
-        let mut result = Vec::new();
+        let mut result = vec![];
         for h in headers {
             result.push(header_from_value(h)?);
         }
@@ -207,7 +207,7 @@ impl Daemon {
 
     pub fn getmempooltxids(&self) -> Result<Vec<Sha256dHash>> {
         let txids: Value = self.request("getrawmempool", json!([/*verbose=*/ false]))?;
-        let mut result = Vec::new();
+        let mut result = vec![];
         for value in txids.as_array().chain_err(|| "non-array result")? {
             result.push(parse_hash(&value).chain_err(|| "invalid txid")?);
         }

src/index.rs

@@ -177,7 +177,7 @@ pub fn index_transaction(txn: &Transaction, height: usize, rows: &mut Vec<Row>)
 }
 
 fn index_block(block: &Block, height: usize) -> Vec<Row> {
-    let mut rows = Vec::new();
+    let mut rows = vec![];
     for txn in &block.txdata {
         index_transaction(&txn, height, &mut rows);
     }

src/mempool.rs

@@ -40,7 +40,7 @@ impl ReadStore for MempoolStore {
     fn scan(&self, prefix: &[u8]) -> Vec<Row> {
         let map = self.map.read().unwrap();
         let range = map.range((Bound::Included(prefix.to_vec()), Bound::Unbounded));
-        let mut rows = Vec::new();
+        let mut rows = vec![];
         for (key, value) in range {
             if !key.starts_with(prefix) {
                 break;
@@ -133,7 +133,7 @@ impl Tracker {
     }
 
     fn update_tx_index(&mut self) {
-        let mut rows = Vec::new();
+        let mut rows = vec![];
         for stats in self.stats.values() {
             index_transaction(&stats.tx, 0, &mut rows)
         }
@@ -145,7 +145,7 @@ impl Tracker {
         entries.sort_unstable_by(|e1, e2| {
             e2.fee_per_vbyte().partial_cmp(&e1.fee_per_vbyte()).unwrap()
         });
-        let mut histogram = Vec::new();
+        let mut histogram = vec![];
         let mut bin_size = 0;
         let mut last_fee_rate = None;
         for e in entries {

src/query.rs

@@ -139,7 +139,7 @@ impl Query {
     }
 
     fn load_txns(&self, store: &ReadStore, prefixes: Vec<HashPrefix>) -> Result<Vec<TxnHeight>> {
-        let mut txns = Vec::new();
+        let mut txns = vec![];
         for txid_prefix in prefixes {
             for tx_row in txrows_by_prefix(store, &txid_prefix) {
                 let txid: Sha256dHash = deserialize(&tx_row.key.txid).unwrap();
@@ -162,7 +162,7 @@ impl Query {
             store,
             txids_by_funding_output(store, &funding.txn_id, funding.output_index),
         )?;
-        let mut spending_inputs = Vec::new();
+        let mut spending_inputs = vec![];
         for t in &spending_txns {
             for input in t.txn.input.iter() {
                 if input.prev_hash == funding.txn_id
@@ -185,7 +185,7 @@ impl Query {
     }
 
     fn find_funding_outputs(&self, t: &TxnHeight, script_hash: &[u8]) -> Vec<FundingOutput> {
-        let mut result = Vec::new();
+        let mut result = vec![];
         let txn_id = t.txn.txid();
         for (index, output) in t.txn.output.iter().enumerate() {
             if compute_script_hash(&output.script_pubkey[..]) == script_hash {
@@ -256,7 +256,7 @@ impl Query {
     pub fn get_headers(&self, heights: &[usize]) -> Vec<BlockHeader> {
         let headers_list = self.app.index().headers_list();
         let headers = headers_list.headers();
-        let mut result = Vec::new();
+        let mut result = vec![];
         for height in heights {
             let header: &BlockHeader = match headers.get(*height) {
                 Some(header) => header.header(),
@@ -290,7 +290,7 @@ impl Query {
             .iter()
             .position(|txid| txid == tx_hash)
             .chain_err(|| format!("missing txid {}", tx_hash))?;
-        let mut merkle = Vec::new();
+        let mut merkle = vec![];
         let mut index = pos;
         while txids.len() > 1 {
             if txids.len() % 2 != 0 {

src/rpc.rs

@@ -99,7 +99,7 @@ impl Connection {
     fn blockchain_block_get_header(&self, params: &[Value]) -> Result<Value> {
         let height = params.get(0).chain_err(|| "missing height")?;
         let height = height.as_u64().chain_err(|| "non-number height")? as usize;
-        let headers = self.query.get_headers(&vec![height]);
+        let headers = self.query.get_headers(&[height]);
         Ok(json!(jsonify_header(&headers[0], height)))
     }
 

src/store.rs

@@ -76,7 +76,7 @@ impl ReadStore for DBStore {
 
     // TODO: use generators
     fn scan(&self, prefix: &[u8]) -> Vec<Row> {
-        let mut rows = Vec::new();
+        let mut rows = vec![];
         let mut iter = self.db.raw_iterator();
         iter.seek(prefix);
         while iter.valid() {