diff --git a/Cargo.toml b/Cargo.toml
index 5cc6e6f..d2fe92c 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -16,6 +16,7 @@ git = "https://github.com/carllerche/eventual"
 
 [dependencies]
 byteorder = "*"
+num = "*"
 num_cpus = "*"
 rand = "*"
 rust-crypto = "*"
diff --git a/src/blockdata/block.rs b/src/blockdata/block.rs
index 1f4de27..29e99b5 100644
--- a/src/blockdata/block.rs
+++ b/src/blockdata/block.rs
@@ -20,7 +20,7 @@
 //! these blocks and the blockchain.
 //!
 
-use std::num::{Zero, from_u64};
+use num::{FromPrimitive, Zero};
 
 use util;
 use util::Error::{SpvBadTarget, SpvBadProofOfWork};
@@ -90,7 +90,7 @@ impl BlockHeader {
         if mant > 0x7FFFFF {
             Zero::zero()
         } else {
-            from_u64::<Uint256>(mant as u64).unwrap() << (expt as usize)
+            <Uint256 as FromPrimitive>::from_u64(mant as u64).unwrap() << (expt as usize)
         }
     }
 
diff --git a/src/blockdata/blockchain.rs b/src/blockdata/blockchain.rs
index eb52e01..d1de5af 100644
--- a/src/blockdata/blockchain.rs
+++ b/src/blockdata/blockchain.rs
@@ -22,8 +22,8 @@
 //! to make sure we are holding the only references.
 //!
 
-use std::num::Zero;
-use std::{marker, num, ptr};
+use num::{FromPrimitive, Zero};
+use std::{marker, ptr};
 
 use blockdata::block::{Block, BlockHeader};
 use blockdata::transaction::Transaction;
@@ -470,7 +470,7 @@ impl Blockchain {
                         // Compute new target
                         let mut target = unsafe { (*prev).block.header.target() };
                         target = target.mul_u32(timespan);
-                        target = target / num::FromPrimitive::from_u64(DIFFCHANGE_TIMESPAN as u64).unwrap();
+                        target = target / FromPrimitive::from_u64(DIFFCHANGE_TIMESPAN as u64).unwrap();
                         // Clamp below MAX_TARGET (difficulty 1)
                         let max = max_target(self.network);
                         if target > max { target = max };
diff --git a/src/blockdata/constants.rs b/src/blockdata/constants.rs
index 33fbe6f..88d026d 100644
--- a/src/blockdata/constants.rs
+++ b/src/blockdata/constants.rs
@@ -20,7 +20,7 @@
 //!
 
 use std::default::Default;
-use std::num::from_u64;
+use num::FromPrimitive;
 
 use blockdata::opcodes;
 use blockdata::script;
@@ -39,7 +39,7 @@ pub static DIFFCHANGE_TIMESPAN: u32 = 14 * 24 * 3600;
 
 /// In Bitcoind this is insanely described as ~((u256)0 >> 32)
 pub fn max_target(_: Network) -> Uint256 {
-    from_u64::<Uint256>(0xFFFF).unwrap() << 208
+    <Uint256 as FromPrimitive>::from_u64(0xFFFF).unwrap() << 208
 }
 
 /// The maximum value allowed in an output (useful for sanity checking,
@@ -73,7 +73,7 @@ fn bitcoin_genesis_tx() -> Transaction {
 
     // Outputs
     let mut out_script = script::Builder::new();
-    out_script.push_slice(hex_bytes("04678afdb0fe5548271967f1a67130b7105cd6a828e03909a67962e0ea1f61deb649f6bc3f4cef38c4f35504e51ec112de5c384df7ba0b8d578a4c702b6bf11d5f").unwrap().as_slice());
+    out_script.push_slice(&hex_bytes("04678afdb0fe5548271967f1a67130b7105cd6a828e03909a67962e0ea1f61deb649f6bc3f4cef38c4f35504e51ec112de5c384df7ba0b8d578a4c702b6bf11d5f").unwrap());
     out_script.push_opcode(opcodes::All::OP_CHECKSIG);
     ret.output.push(TxOut {
         value: 50 * COIN_VALUE,
diff --git a/src/blockdata/opcodes.rs b/src/blockdata/opcodes.rs
index c2d5e87..f648601 100644
--- a/src/blockdata/opcodes.rs
+++ b/src/blockdata/opcodes.rs
@@ -24,7 +24,6 @@ use serde;
 
 // Heavy stick to translate between opcode types
 use std::mem::transmute;
-use std::fmt;
 
 use network::serialize::{SimpleDecoder, SimpleEncoder};
 use network::encodable::{ConsensusDecodable, ConsensusEncodable};
diff --git a/src/blockdata/script.rs b/src/blockdata/script.rs
index 8bcc621..b2dfb20 100644
--- a/src/blockdata/script.rs
+++ b/src/blockdata/script.rs
@@ -28,7 +28,6 @@ use std::hash;
 use std::char::from_digit;
 use std::default::Default;
 use std::ops;
-use serialize::json;
 use serialize::hex::ToHex;
 
 use crypto::digest::Digest;
@@ -56,9 +55,10 @@ impl Clone for Script {
     }
 }
 
-#[derive(PartialEq, Eq, Debug, Clone, Display)]
+#[derive(PartialEq, Eq, Debug, Clone)]
 /// An object which can be used to construct a script piece by piece
 pub struct Builder(Vec<u8>);
+display_from_debug!(Builder);
 
 impl hash::Hash for Script {
     #[inline]
@@ -875,7 +875,7 @@ impl AbstractStackElem {
         }
 
         let validators = self.validators.clone();
-        for v in validators.iter().map(|v| v.clone()) {
+        for v in validators.iter().cloned() {
             try!((v.update)(self, &v.args));
         }
         Ok(())
@@ -2084,12 +2084,10 @@ impl Script {
     /// Checks whether a script pubkey is a p2sh output
     #[inline]
     pub fn is_p2sh(&self) -> bool {
-        unsafe {
-            self.0.len() == 23 &&
-            self.0[0] == opcodes::All::OP_HASH160 as u8 &&
-            self.0[1] == opcodes::All::OP_PUSHBYTES_20 as u8 &&
-            self.0[22] == opcodes::All::OP_EQUAL as u8
-        }
+        self.0.len() == 23 &&
+        self.0[0] == opcodes::All::OP_HASH160 as u8 &&
+        self.0[1] == opcodes::All::OP_PUSHBYTES_20 as u8 &&
+        self.0[22] == opcodes::All::OP_EQUAL as u8
     }
 
     /// Whether a script can be proven to have no satisfying input
@@ -2503,13 +2501,15 @@ impl Builder {
             _ => panic!("tried to put a 4bn+ sized object into a script!")
         }
         // Then push the acraw
-        self.0.extend(data.iter().map(|n| *n));
+        self.0.extend(data.iter().cloned());
     }
 
+    /// Adds a single opcode to the script
     pub fn push_opcode(&mut self, data: opcodes::All) {
         self.0.push(data as u8);
     }
 
+    /// Converts the `Builder` into an unmodifiable `Script`
     pub fn into_script(self) -> Script {
         Script(self.0.into_boxed_slice())
     }
@@ -2594,16 +2594,16 @@ mod test {
         script.push_int(4);  comp.push(85u8); assert_eq!(&script[..], &comp[..]);
         script.push_int(-1); comp.push(80u8); assert_eq!(&script[..], &comp[..]);
         // forced scriptint
-        script.push_scriptint(4); comp.push_all(&[1u8, 4]); assert_eq!(&script[..], &comp[..]);
+        script.push_scriptint(4); comp.extend([1u8, 4].iter().cloned()); assert_eq!(&script[..], &comp[..]);
         // big ints
-        script.push_int(17); comp.push_all(&[1u8, 17]); assert_eq!(&script[..], &comp[..]);
-        script.push_int(10000); comp.push_all(&[2u8, 16, 39]); assert_eq!(&script[..], &comp[..]);
+        script.push_int(17); comp.extend([1u8, 17].iter().cloned()); assert_eq!(&script[..], &comp[..]);
+        script.push_int(10000); comp.extend([2u8, 16, 39].iter().cloned()); assert_eq!(&script[..], &comp[..]);
         // notice the sign bit set here, hence the extra zero/128 at the end
-        script.push_int(10000000); comp.push_all(&[4u8, 128, 150, 152, 0]); assert_eq!(&script[..], &comp[..]);
-        script.push_int(-10000000); comp.push_all(&[4u8, 128, 150, 152, 128]); assert_eq!(&script[..], &comp[..]);
+        script.push_int(10000000); comp.extend([4u8, 128, 150, 152, 0].iter().cloned()); assert_eq!(&script[..], &comp[..]);
+        script.push_int(-10000000); comp.extend([4u8, 128, 150, 152, 128].iter().cloned()); assert_eq!(&script[..], &comp[..]);
 
         // data
-        script.push_slice("NRA4VR".as_bytes()); comp.push_all(&[6u8, 78, 82, 65, 52, 86, 82]); assert_eq!(&script[..], &comp[..]);
+        script.push_slice("NRA4VR".as_bytes()); comp.extend([6u8, 78, 82, 65, 52, 86, 82].iter().cloned()); assert_eq!(&script[..], &comp[..]);
 
         // opcodes 
         script.push_opcode(opcodes::All::OP_CHECKSIG); comp.push(0xACu8); assert_eq!(&script[..], &comp[..]);
diff --git a/src/blockdata/utxoset.rs b/src/blockdata/utxoset.rs
index 77ee3e3..95867f8 100644
--- a/src/blockdata/utxoset.rs
+++ b/src/blockdata/utxoset.rs
@@ -134,7 +134,7 @@ impl UtxoSet {
     fn add_utxos(&mut self, tx: &Transaction, height: u32) -> Option<UtxoNode> {
         let txid = tx.bitcoin_hash();
         // Locate node if it's already there
-        let new_node = unsafe {
+        let new_node = {
             let mut new_node = Vec::with_capacity(tx.output.len());
             for txo in tx.output.iter() {
                 // Unsafe since we are not uninitializing the old data in the vector
@@ -353,14 +353,12 @@ impl UtxoSet {
                             node
                         }
                         None => {
-                            unsafe {
-                                let mut thinvec = Vec::with_capacity(n as usize + 1);
-                                for _ in 0..n {
-                                    thinvec.push(None);
-                                }
-                                thinvec.push(Some(txo));
-                                UtxoNode { outputs: thinvec.into_boxed_slice(), height: height }
+                            let mut thinvec = Vec::with_capacity(n as usize + 1);
+                            for _ in 0..n {
+                                thinvec.push(None);
                             }
+                            thinvec.push(Some(txo));
+                            UtxoNode { outputs: thinvec.into_boxed_slice(), height: height }
                         }
                     };
                     // Ram it back into the tree
@@ -416,7 +414,6 @@ impl UtxoSet {
 
 #[cfg(test)]
 mod tests {
-    use std::prelude::*;
     use serialize::hex::FromHex;
 
     use super::{UtxoSet, ValidationLevel};
diff --git a/src/internal_macros.rs b/src/internal_macros.rs
index 0f36991..a9bacad 100644
--- a/src/internal_macros.rs
+++ b/src/internal_macros.rs
@@ -167,7 +167,7 @@ macro_rules! impl_array_newtype_encodable {
                                     None => return Err(::serde::de::Error::end_of_stream_error())
                                 };
                             }
-                            v.end();
+                            try!(v.end());
                             Ok($thing(ret))
                         }
                     }
diff --git a/src/lib.rs b/src/lib.rs
index 07e2968..2cd5574 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -29,28 +29,27 @@
 
 // Experimental features we need
 #![feature(box_patterns)]
-#![feature(custom_derive, plugin)]
-#![feature(overloaded_calls)]
-#![feature(unsafe_destructor)]
-#![feature(unboxed_closure_sugar)]
-#![feature(unboxed_closures)]
 #![feature(concat_idents)]
+#![feature(custom_derive, plugin)]
+#![feature(hash)]
+#![feature(ip_addr)]
 #![feature(slice_patterns)]
+#![feature(std_misc)]
+#![cfg_attr(test, feature(test))]
 
 // Coding conventions
-#![warn(non_uppercase_statics)]
+#![deny(non_upper_case_globals)]
 #![deny(non_camel_case_types)]
 #![deny(non_snake_case)]
 #![deny(unused_mut)]
-#![warn(missing_doc)]
+#![deny(missing_docs)]
 
 #![plugin(serde_macros)]
 
-extern crate alloc;
 extern crate byteorder;
-extern crate collections;
 extern crate crypto;
 extern crate eventual;
+extern crate num;
 extern crate num_cpus;
 extern crate rand;
 extern crate rustc_serialize as serialize;
@@ -71,6 +70,3 @@ pub mod blockdata;
 pub mod util;
 pub mod wallet;
 
-/// I dunno where else to put this..
-fn assert_type_is_copy<T: Copy>() { }
-
diff --git a/src/network/encodable.rs b/src/network/encodable.rs
index aea476a..8b0f7a0 100644
--- a/src/network/encodable.rs
+++ b/src/network/encodable.rs
@@ -203,7 +203,7 @@ impl_array!(12);
 impl_array!(16);
 impl_array!(32);
 
-impl<'a, S: SimpleEncoder, T: ConsensusEncodable<S>> ConsensusEncodable<S> for &'a [T] {
+impl<S: SimpleEncoder, T: ConsensusEncodable<S>> ConsensusEncodable<S> for [T] {
     #[inline]
     fn consensus_encode(&self, s: &mut S) -> Result<(), S::Error> {
         try!(VarInt(self.len() as u64).consensus_encode(s));
@@ -239,12 +239,10 @@ impl<D: SimpleDecoder, T: ConsensusDecodable<D>> ConsensusDecodable<D> for Box<[
     #[inline]
     fn consensus_decode(d: &mut D) -> Result<Box<[T]>, D::Error> {
         let VarInt(len): VarInt = try!(ConsensusDecodable::consensus_decode(d));
-        unsafe {
-            let len = len as usize;
-            let mut ret = Vec::with_capacity(len);
-            for i in 0..len { ret.push(try!(ConsensusDecodable::consensus_decode(d))); }
-            Ok(ret.into_boxed_slice())
-        }
+        let len = len as usize;
+        let mut ret = Vec::with_capacity(len);
+        for _ in 0..len { ret.push(try!(ConsensusDecodable::consensus_decode(d))); }
+        Ok(ret.into_boxed_slice())
     }
 }
 
@@ -457,7 +455,7 @@ mod tests {
     #[test]
     fn serialize_vector_test() {
         assert_eq!(serialize(&vec![1u8, 2, 3]).ok(), Some(vec![3u8, 1, 2, 3]));
-        assert_eq!(serialize(&[1u8, 2, 3].as_slice()).ok(), Some(vec![3u8, 1, 2, 3]));
+        assert_eq!(serialize(&[1u8, 2, 3][..]).ok(), Some(vec![3u8, 1, 2, 3]));
         // TODO: test vectors of more interesting objects
     }
 
@@ -531,7 +529,7 @@ mod tests {
 
     #[test]
     fn deserialize_strbuf_test() {
-        assert_eq!(deserialize(&[6u8, 0x41, 0x6e, 0x64, 0x72, 0x65, 0x77]).ok(), Some(String::from_str("Andrew")));
+        assert_eq!(deserialize(&[6u8, 0x41, 0x6e, 0x64, 0x72, 0x65, 0x77]).ok(), Some("Andrew".to_string()));
     }
 
     #[test]
diff --git a/src/network/listener.rs b/src/network/listener.rs
index 2be156c..fe2d1af 100644
--- a/src/network/listener.rs
+++ b/src/network/listener.rs
@@ -18,7 +18,7 @@
 //! to connect to a peer, send network messages, and receive Bitcoin data.
 //!
 
-use std::{io, thread};
+use std::thread;
 use std::sync::mpsc::{channel, Receiver};
 
 use network::constants::Network;
@@ -75,7 +75,7 @@ pub trait Listener {
                         // We have to pass the message to the main thread for processing,
                         // unfortunately, because sipa says we have to handle everything
                         // in order.
-                        recv_tx.send(message::SocketResponse::MessageReceived(payload));
+                        recv_tx.send(message::SocketResponse::MessageReceived(payload)).unwrap();
                     }
                     Err(e) => {
                         // On failure we send an error message to the main thread, along with
@@ -83,8 +83,8 @@ pub trait Listener {
                         // thread. (If we simply exited immediately, the channel would be torn
                         // down and the main thread would never see the error message.)
                         let (tx, rx) = channel();
-                        recv_tx.send(message::SocketResponse::ConnectionFailed(e, tx));
-                        rx.recv();
+                        recv_tx.send(message::SocketResponse::ConnectionFailed(e, tx)).unwrap();
+                        rx.recv().unwrap();
                         break;
                     }
                 }
diff --git a/src/network/message.rs b/src/network/message.rs
index 67db4d9..a47aeeb 100644
--- a/src/network/message.rs
+++ b/src/network/message.rs
@@ -19,9 +19,8 @@
 //! also defines (de)serialization routines for many primitives.
 //!
 
-use collections::Vec;
 use std::iter;
-use std::io::{self, Cursor};
+use std::io::Cursor;
 use std::sync::mpsc::Sender;
 
 use blockdata::block;
@@ -41,9 +40,14 @@ pub struct CommandString(pub String);
 impl<S: SimpleEncoder> ConsensusEncodable<S> for CommandString {
     #[inline]
     fn consensus_encode(&self, s: &mut S) -> Result<(), S::Error> {
+        use std::intrinsics::copy_nonoverlapping;
+        use std::mem;
+
         let &CommandString(ref inner_str) = self;
         let mut rawbytes = [0u8; 12]; 
-        rawbytes.clone_from_slice(inner_str.as_bytes().as_slice());
+        unsafe { copy_nonoverlapping(inner_str.as_bytes().as_ptr(),
+                                     rawbytes.as_mut_ptr(),
+                                     mem::size_of::<[u8; 12]>()); }
         rawbytes.consensus_encode(s)
     }
 }
@@ -165,7 +169,7 @@ impl<D: SimpleDecoder<Error=util::Error>> ConsensusDecodable<D> for RawNetworkMe
         let CheckedData(raw_payload): CheckedData = try!(ConsensusDecodable::consensus_decode(d));
 
         let mut mem_d = RawDecoder::new(Cursor::new(raw_payload));
-        let payload = match cmd.as_slice() {
+        let payload = match &cmd[..] {
             "version" => NetworkMessage::Version(try!(propagate_err("version".to_string(), ConsensusDecodable::consensus_decode(&mut mem_d)))),
             "verack"  => NetworkMessage::Verack,
             "addr"    => NetworkMessage::Addr(try!(propagate_err("addr".to_string(), ConsensusDecodable::consensus_decode(&mut mem_d)))),
@@ -196,7 +200,7 @@ mod test {
 
     #[test]
     fn serialize_commandstring_test() {
-        let cs = CommandString(String::from_str("Andrew"));
+        let cs = CommandString("Andrew".to_string());
         assert_eq!(serialize(&cs).ok(), Some(vec![0x41u8, 0x6e, 0x64, 0x72, 0x65, 0x77, 0, 0, 0, 0, 0, 0]));
     }
 
@@ -204,7 +208,7 @@ mod test {
     fn deserialize_commandstring_test() {
         let cs: Result<CommandString, _> = deserialize(&[0x41u8, 0x6e, 0x64, 0x72, 0x65, 0x77, 0, 0, 0, 0, 0, 0]);
         assert!(cs.is_ok());
-        assert_eq!(cs.unwrap(), CommandString(String::from_str("Andrew")));
+        assert_eq!(cs.unwrap(), CommandString("Andrew".to_string()));
 
         let short_cs: Result<CommandString, _> = deserialize(&[0x41u8, 0x6e, 0x64, 0x72, 0x65, 0x77, 0, 0, 0, 0, 0]);
         assert!(short_cs.is_err());
diff --git a/src/network/message_network.rs b/src/network/message_network.rs
index 34a19b8..f6a113d 100644
--- a/src/network/message_network.rs
+++ b/src/network/message_network.rs
@@ -96,7 +96,7 @@ mod tests {
         assert_eq!(real_decode.timestamp, 1401217254);
         // address decodes should be covered by Address tests
         assert_eq!(real_decode.nonce, 16735069437859780935);
-        assert_eq!(real_decode.user_agent, String::from_str("/Satoshi:0.9.99/"));
+        assert_eq!(real_decode.user_agent, "/Satoshi:0.9.99/".to_string());
         assert_eq!(real_decode.start_height, 302892);
         assert_eq!(real_decode.relay, true);
 
diff --git a/src/network/serialize.rs b/src/network/serialize.rs
index 826160f..456edaa 100644
--- a/src/network/serialize.rs
+++ b/src/network/serialize.rs
@@ -19,8 +19,7 @@
 //! It also defines (de)serialization routines for many primitives.
 //!
 
-use collections::Vec;
-use std::io::{self, Cursor, Read, Write};
+use std::io::{Cursor, Read, Write};
 use byteorder::{LittleEndian, WriteBytesExt, ReadBytesExt};
 use serialize::hex::ToHex;
 
@@ -42,7 +41,7 @@ impl BitcoinHash for Vec<u8> {
 }
 
 /// Encode an object into a vector
-pub fn serialize<T>(data: &T) -> Result<Vec<u8>, util::Error>
+pub fn serialize<T: ?Sized>(data: &T) -> Result<Vec<u8>, util::Error>
      where T: ConsensusEncodable<RawEncoder<Cursor<Vec<u8>>>>,
 {
     let mut encoder = RawEncoder::new(Cursor::new(vec![]));
@@ -51,7 +50,7 @@ pub fn serialize<T>(data: &T) -> Result<Vec<u8>, util::Error>
 }
 
 /// Encode an object into a hex-encoded string
-pub fn serialize_hex<T>(data: &T) -> Result<String, util::Error>
+pub fn serialize_hex<T: ?Sized>(data: &T) -> Result<String, util::Error>
      where T: ConsensusEncodable<RawEncoder<Cursor<Vec<u8>>>>
 {
     let serial = try!(serialize(data));
@@ -92,57 +91,59 @@ impl<R: Read> RawDecoder<R> {
 
 /// A simple Encoder trait
 pub trait SimpleEncoder {
-  type Error;
+    /// An encoding error
+    type Error;
+ 
+    /// Output a 64-bit uint
+    fn emit_u64(&mut self, v: u64) -> Result<(), Self::Error>;
+    /// Output a 32-bit uint
+    fn emit_u32(&mut self, v: u32) -> Result<(), Self::Error>;
+    /// Output a 16-bit uint
+    fn emit_u16(&mut self, v: u16) -> Result<(), Self::Error>;
+    /// Output a 8-bit uint
+    fn emit_u8(&mut self, v: u8) -> Result<(), Self::Error>;
 
-  /// Output a 64-bit uint
-  fn emit_u64(&mut self, v: u64) -> Result<(), Self::Error>;
-  /// Output a 32-bit uint
-  fn emit_u32(&mut self, v: u32) -> Result<(), Self::Error>;
-  /// Output a 16-bit uint
-  fn emit_u16(&mut self, v: u16) -> Result<(), Self::Error>;
-  /// Output a 8-bit uint
-  fn emit_u8(&mut self, v: u8) -> Result<(), Self::Error>;
+    /// Output a 64-bit int
+    fn emit_i64(&mut self, v: i64) -> Result<(), Self::Error>;
+    /// Output a 32-bit int
+    fn emit_i32(&mut self, v: i32) -> Result<(), Self::Error>;
+    /// Output a 16-bit int
+    fn emit_i16(&mut self, v: i16) -> Result<(), Self::Error>;
+    /// Output a 8-bit int
+    fn emit_i8(&mut self, v: i8) -> Result<(), Self::Error>;
 
-  /// Output a 64-bit int
-  fn emit_i64(&mut self, v: i64) -> Result<(), Self::Error>;
-  /// Output a 32-bit int
-  fn emit_i32(&mut self, v: i32) -> Result<(), Self::Error>;
-  /// Output a 16-bit int
-  fn emit_i16(&mut self, v: i16) -> Result<(), Self::Error>;
-  /// Output a 8-bit int
-  fn emit_i8(&mut self, v: i8) -> Result<(), Self::Error>;
-
-  /// Output a boolean
-  fn emit_bool(&mut self, v: bool) -> Result<(), Self::Error>;
+    /// Output a boolean
+    fn emit_bool(&mut self, v: bool) -> Result<(), Self::Error>;
 }
 
 /// A simple Decoder trait
 pub trait SimpleDecoder {
-  type Error;
+    /// A decoding error
+    type Error;
 
-  /// Read a 64-bit uint
-  fn read_u64(&mut self) -> Result<u64, Self::Error>;
-  /// Read a 32-bit uint
-  fn read_u32(&mut self) -> Result<u32, Self::Error>;
-  /// Read a 16-bit uint
-  fn read_u16(&mut self) -> Result<u16, Self::Error>;
-  /// Read a 8-bit uint
-  fn read_u8(&mut self) -> Result<u8, Self::Error>;
+    /// Read a 64-bit uint
+    fn read_u64(&mut self) -> Result<u64, Self::Error>;
+    /// Read a 32-bit uint
+    fn read_u32(&mut self) -> Result<u32, Self::Error>;
+    /// Read a 16-bit uint
+    fn read_u16(&mut self) -> Result<u16, Self::Error>;
+    /// Read a 8-bit uint
+    fn read_u8(&mut self) -> Result<u8, Self::Error>;
 
-  /// Read a 64-bit int
-  fn read_i64(&mut self) -> Result<i64, Self::Error>;
-  /// Read a 32-bit int
-  fn read_i32(&mut self) -> Result<i32, Self::Error>;
-  /// Read a 16-bit int
-  fn read_i16(&mut self) -> Result<i16, Self::Error>;
-  /// Read a 8-bit int
-  fn read_i8(&mut self) -> Result<i8, Self::Error>;
+    /// Read a 64-bit int
+    fn read_i64(&mut self) -> Result<i64, Self::Error>;
+    /// Read a 32-bit int
+    fn read_i32(&mut self) -> Result<i32, Self::Error>;
+    /// Read a 16-bit int
+    fn read_i16(&mut self) -> Result<i16, Self::Error>;
+    /// Read a 8-bit int
+    fn read_i8(&mut self) -> Result<i8, Self::Error>;
 
-  /// Read a boolean
-  fn read_bool(&mut self) -> Result<bool, Self::Error>;
+    /// Read a boolean
+    fn read_bool(&mut self) -> Result<bool, Self::Error>;
 
-  /// Signal a decoding error
-  fn error(&mut self, err: String) -> Self::Error;
+    /// Signal a decoding error
+    fn error(&mut self, err: String) -> Self::Error;
 }
 
 macro_rules! encoder_fn {
diff --git a/src/network/socket.rs b/src/network/socket.rs
index d1b032d..525e9a9 100644
--- a/src/network/socket.rs
+++ b/src/network/socket.rs
@@ -19,7 +19,7 @@
 
 use time::now;
 use rand::{thread_rng, Rng};
-use std::io::{self, Cursor, Write};
+use std::io::{self, Write};
 use std::net;
 use std::sync::{Arc, Mutex};
 
@@ -57,7 +57,7 @@ pub struct Socket {
 
 macro_rules! with_socket(($s:ident, $sock:ident, $body:block) => ({
     use ::std::ops::DerefMut;
-    let mut sock_lock = $s.socket.lock();
+    let sock_lock = $s.socket.lock();
     match sock_lock {
         Err(_) => {
             let io_err = io::Error::new(io::ErrorKind::NotConnected,
@@ -89,7 +89,7 @@ impl Socket {
             socket: Arc::new(Mutex::new(None)),
             services: 0,
             version_nonce: rng.gen(),
-            user_agent: String::from_str(constants::USER_AGENT),
+            user_agent: constants::USER_AGENT.to_string(),
             magic: constants::magic(network)
         }
     }
diff --git a/src/test_macros.rs b/src/test_macros.rs
new file mode 100644
index 0000000..44b55b1
--- /dev/null
+++ b/src/test_macros.rs
@@ -0,0 +1,35 @@
+// Rust Bitcoin Library
+// Written in 2014 by
+//     Andrew Poelstra <apoelstra@wpsoftware.net>
+//
+// To the extent possible under law, the author(s) have dedicated all
+// copyright and related and neighboring rights to this software to
+// the public domain worldwide. This software is distributed without
+// any warranty.
+//
+// You should have received a copy of the CC0 Public Domain Dedication
+// along with this software.
+// If not, see <http://creativecommons.org/publicdomain/zero/1.0/>.
+//
+
+//! # Macros
+//!
+//! Internal macros used for unit tests
+
+#[macro_export]
+macro_rules! serde_round_trip (
+    ($var:expr) => ({
+        use serde::{json, Serialize, Deserialize};
+
+        let start = $var;
+        let mut encoded = Vec::new();
+        {
+            let mut serializer = json::ser::Serializer::new(&mut encoded);
+            start.serialize(&mut serializer).unwrap();
+        }
+        let mut deserializer = json::de::Deserializer::new(encoded.iter().map(|c| Ok(*c))).unwrap();
+        let decoded = Deserialize::deserialize(&mut deserializer);
+        assert_eq!(Some(start), decoded.ok());
+    })
+);
+
diff --git a/src/util/base58.rs b/src/util/base58.rs
index 5ef522a..6238d8a 100644
--- a/src/util/base58.rs
+++ b/src/util/base58.rs
@@ -15,9 +15,6 @@
 //! # Base58 encoder and decoder
 
 use byteorder::{ByteOrder, LittleEndian, WriteBytesExt};
-
-use std::{iter, str};
-
 use util::hash::Sha256dHash;
 
 /// An error that might occur during base58 decoding
@@ -129,17 +126,14 @@ pub fn base58_encode_slice(data: &[u8]) -> String {
         assert_eq!(carry, 0);
     }
 
-    // Unsafely translate the bytes to a utf8 string
-    unsafe {
-        // Copy leading zeroes directly
-        let mut ret: Vec<u8> = data.iter().take_while(|&&x| x == 0)
-                                          .map(|_| BASE58_CHARS[0])
-                                          .collect();
-        // Copy rest of string
-        ret.extend(scratch.into_iter().skip_while(|&x| x == 0)
-                                      .map(|x| BASE58_CHARS[x as usize]));
-        String::from_utf8(ret).unwrap()
-    }
+    // Copy leading zeroes directly
+    let mut ret: Vec<u8> = data.iter().take_while(|&&x| x == 0)
+                                      .map(|_| BASE58_CHARS[0])
+                                      .collect();
+    // Copy rest of string
+    ret.extend(scratch.into_iter().skip_while(|&x| x == 0)
+                                  .map(|x| BASE58_CHARS[x as usize]));
+    String::from_utf8(ret).unwrap()
 }
 
 /// Trait for objects which can be written as base58
@@ -157,7 +151,7 @@ pub trait ToBase58 {
     fn to_base58check(&self) -> String {
         let mut data = self.base58_layout();
         let checksum = Sha256dHash::from_data(&data).into_le().low_u32();
-        data.write_u32::<LittleEndian>(checksum);
+        data.write_u32::<LittleEndian>(checksum).unwrap();
         base58_encode_slice(&data)
     }
 }
diff --git a/src/util/hash.rs b/src/util/hash.rs
index 90a095e..3ef97ad 100644
--- a/src/util/hash.rs
+++ b/src/util/hash.rs
@@ -21,16 +21,14 @@ use std::default::Default;
 use std::fmt::{self, Write};
 use std::io::Cursor;
 use std::mem::transmute;
-use std::hash;
 use serde;
 
-use byteorder::{ByteOrder, LittleEndian};
 use crypto::digest::Digest;
 use crypto::sha2::Sha256;
 use crypto::ripemd160::Ripemd160;
 
 use network::encodable::{ConsensusDecodable, ConsensusEncodable};
-use network::serialize::{RawEncoder, BitcoinHash, SimpleDecoder};
+use network::serialize::{RawEncoder, BitcoinHash};
 use util::uint::Uint256;
 
 /// A Bitcoin hash, 32-bytes, computed from x as SHA256(SHA256(x))
@@ -39,7 +37,7 @@ impl_array_newtype!(Sha256dHash, u8, 32);
 
 impl ::std::fmt::Debug for Sha256dHash {
     fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
-        write!(f, "{}", self.be_hex_string().as_slice())
+        write!(f, "{}", self.be_hex_string())
     }
 }
 
@@ -214,7 +212,6 @@ impl_newtype_consensus_encoding!(Sha256dHash);
 impl fmt::LowerHex for Sha256dHash {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         let &Sha256dHash(data) = self;
-        let mut rv = [0; 64];
         for ch in data.iter().rev() {
             try!(write!(f, "{:02x}", ch));
         }
@@ -264,10 +261,7 @@ impl <T: BitcoinHash> MerkleRoot for Vec<T> {
 
 #[cfg(test)]
 mod tests {
-    use std::prelude::*;
-    use std::io::Cursor;
-    use std::num::FromPrimitive;
-    use std::str::from_utf8;
+    use num::FromPrimitive;
     use serde::{json, Serialize, Deserialize};
 
     use network::serialize::{serialize, deserialize};
diff --git a/src/util/misc.rs b/src/util/misc.rs
index 0c9dd31..23808ce 100644
--- a/src/util/misc.rs
+++ b/src/util/misc.rs
@@ -97,8 +97,6 @@ pub fn script_find_and_remove(haystack: &mut Vec<u8>, needle: &[u8]) -> usize {
 
 #[cfg(test)]
 mod tests {
-    use std::prelude::*;
-
     use super::script_find_and_remove;
     use super::hex_bytes;
 
diff --git a/src/util/patricia_tree.rs b/src/util/patricia_tree.rs
index c49106a..e84098b 100644
--- a/src/util/patricia_tree.rs
+++ b/src/util/patricia_tree.rs
@@ -22,8 +22,8 @@
 
 use std::fmt::Debug;
 use std::marker;
-use std::num::{Zero, One};
 use std::{cmp, fmt, ops, ptr};
+use num::{Zero, One};
 
 use network::encodable::{ConsensusDecodable, ConsensusEncodable};
 use network::serialize::{SimpleDecoder, SimpleEncoder};
@@ -549,9 +549,8 @@ impl<'a, K: Copy, V> Iterator for MutItems<'a, K, V> {
 
 #[cfg(test)]
 mod tests {
-    use std::prelude::*;
-    use std::num::Zero;
-    use std::num::FromPrimitive;
+    use num::Zero;
+    use num::FromPrimitive;
 
     use network::serialize::{deserialize, serialize};
     use util::hash::Sha256dHash;
diff --git a/src/util/uint.rs b/src/util/uint.rs
index 252e5a5..cb2e52b 100644
--- a/src/util/uint.rs
+++ b/src/util/uint.rs
@@ -19,9 +19,8 @@
 //!
 
 use std::fmt;
-use std::num::{Zero, One};
+use num::{FromPrimitive, Zero, One};
 
-use network::serialize::RawEncoder;
 use util::BitArray;
 
 macro_rules! construct_uint {
@@ -66,7 +65,7 @@ macro_rules! construct_uint {
             }
         }
 
-        impl ::std::num::FromPrimitive for $name {
+        impl FromPrimitive for $name {
             #[inline]
             fn from_u64(init: u64) -> Option<$name> {
                 let mut ret = [0; $n_words];
@@ -76,15 +75,17 @@ macro_rules! construct_uint {
 
             #[inline]
             fn from_i64(init: i64) -> Option<$name> {
-                ::std::num::FromPrimitive::from_u64(init as u64)
+                assert!(init >= 0);
+                FromPrimitive::from_u64(init as u64)
             }
         }
 
-        impl ::std::num::Zero for $name {
+        impl Zero for $name {
             fn zero() -> $name { $name([0; $n_words]) }
+            fn is_zero(&self) -> bool { self.0.iter().all(|&n| n == 0) }
         }
 
-        impl ::std::num::One for $name {
+        impl One for $name {
             fn one() -> $name {
                 $name({ let mut ret = [0; $n_words]; ret[0] = 1; ret })
             }
@@ -289,7 +290,6 @@ macro_rules! construct_uint {
         impl ::std::ops::Shr<usize> for $name {
             type Output = $name;
 
-            #[allow(unsigned_negate)]
             fn shr(self, shift: usize) -> $name {
                 let $name(ref original) = self;
                 let mut ret = [0u64; $n_words];
@@ -388,7 +388,7 @@ impl Uint256 {
 
 #[cfg(test)]
 mod tests {
-    use std::num::from_u64;
+    use num::FromPrimitive;
 
     use network::serialize::{deserialize, serialize};
     use util::uint::Uint256;
@@ -396,14 +396,14 @@ mod tests {
 
     #[test]
     pub fn uint256_bits_test() {
-        assert_eq!(from_u64::<Uint256>(255).unwrap().bits(), 8);
-        assert_eq!(from_u64::<Uint256>(256).unwrap().bits(), 9);
-        assert_eq!(from_u64::<Uint256>(300).unwrap().bits(), 9);
-        assert_eq!(from_u64::<Uint256>(60000).unwrap().bits(), 16);
-        assert_eq!(from_u64::<Uint256>(70000).unwrap().bits(), 17);
+        assert_eq!(<Uint256 as FromPrimitive>::from_u64(255).unwrap().bits(), 8);
+        assert_eq!(<Uint256 as FromPrimitive>::from_u64(256).unwrap().bits(), 9);
+        assert_eq!(<Uint256 as FromPrimitive>::from_u64(300).unwrap().bits(), 9);
+        assert_eq!(<Uint256 as FromPrimitive>::from_u64(60000).unwrap().bits(), 16);
+        assert_eq!(<Uint256 as FromPrimitive>::from_u64(70000).unwrap().bits(), 17);
 
         // Try to read the following lines out loud quickly
-        let mut shl: Uint256 = from_u64(70000).unwrap();
+        let mut shl = <Uint256 as FromPrimitive>::from_u64(70000).unwrap();
         shl = shl << 100;
         assert_eq!(shl.bits(), 117);
         shl = shl << 100;
@@ -412,11 +412,11 @@ mod tests {
         assert_eq!(shl.bits(), 0);
 
         // Bit set check
-        assert!(!from_u64::<Uint256>(10).unwrap().bit(0));
-        assert!(from_u64::<Uint256>(10).unwrap().bit(1));
-        assert!(!from_u64::<Uint256>(10).unwrap().bit(2));
-        assert!(from_u64::<Uint256>(10).unwrap().bit(3));
-        assert!(!from_u64::<Uint256>(10).unwrap().bit(4));
+        assert!(!<Uint256 as FromPrimitive>::from_u64(10).unwrap().bit(0));
+        assert!(<Uint256 as FromPrimitive>::from_u64(10).unwrap().bit(1));
+        assert!(!<Uint256 as FromPrimitive>::from_u64(10).unwrap().bit(2));
+        assert!(<Uint256 as FromPrimitive>::from_u64(10).unwrap().bit(3));
+        assert!(!<Uint256 as FromPrimitive>::from_u64(10).unwrap().bit(4));
     }
 
     #[test]
@@ -438,7 +438,7 @@ mod tests {
 
     #[test]
     pub fn uint256_arithmetic_test() {
-        let init: Uint256 = from_u64(0xDEADBEEFDEADBEEF).unwrap();
+        let init = <Uint256 as FromPrimitive>::from_u64(0xDEADBEEFDEADBEEF).unwrap();
         let copy = init;
 
         let add = init + copy;
@@ -459,17 +459,17 @@ mod tests {
         let mult = sub.mul_u32(300);
         assert_eq!(mult, Uint256([0x8C8C3EE70C644118u64, 0x0209E7378231E632, 0, 0]));
         // Division
-        assert_eq!(from_u64::<Uint256>(105).unwrap() /
-                   from_u64::<Uint256>(5).unwrap(),
-                   from_u64::<Uint256>(21).unwrap());
-        let div = mult / from_u64::<Uint256>(300).unwrap();
+        assert_eq!(<Uint256 as FromPrimitive>::from_u64(105).unwrap() /
+                   <Uint256 as FromPrimitive>::from_u64(5).unwrap(),
+                   <Uint256 as FromPrimitive>::from_u64(21).unwrap());
+        let div = mult / <Uint256 as FromPrimitive>::from_u64(300).unwrap();
         assert_eq!(div, Uint256([0x9F30411021524112u64, 0x0001BD5B7DDFBD5A, 0, 0]));
         // TODO: bit inversion
     }
 
     #[test]
     pub fn uint256_bitslice_test() {
-        let init = from_u64::<Uint256>(0xDEADBEEFDEADBEEF).unwrap();
+        let init = <Uint256 as FromPrimitive>::from_u64(0xDEADBEEFDEADBEEF).unwrap();
         let add = init + (init << 64);
         assert_eq!(add.bit_slice(64, 128), init);
         assert_eq!(add.mask(64), init);
@@ -479,7 +479,7 @@ mod tests {
     pub fn uint256_extreme_bitshift_test() {
         // Shifting a u64 by 64 bits gives an undefined value, so make sure that
         // we're doing the Right Thing here
-        let init = from_u64::<Uint256>(0xDEADBEEFDEADBEEF).unwrap();
+        let init = <Uint256 as FromPrimitive>::from_u64(0xDEADBEEFDEADBEEF).unwrap();
 
         assert_eq!(init << 64, Uint256([0, 0xDEADBEEFDEADBEEF, 0, 0]));
         let add = (init << 64) + init;
diff --git a/src/wallet/address.rs b/src/wallet/address.rs
index 0e95a97..ca95847 100644
--- a/src/wallet/address.rs
+++ b/src/wallet/address.rs
@@ -127,7 +127,7 @@ impl ToBase58 for Address {
                 Network::Testnet => 111
             }
         ];
-        ret.push_all(&self.hash[..]);
+        ret.extend(self.hash[..].iter().cloned());
         ret
     }
 }
diff --git a/src/wallet/address_index.rs b/src/wallet/address_index.rs
index 0d1d9a8..bd1f691 100644
--- a/src/wallet/address_index.rs
+++ b/src/wallet/address_index.rs
@@ -19,7 +19,7 @@
 //!
 
 use std::collections::HashMap;
-use std::hash::{hash, Hash, Hasher, SipHasher};
+use std::hash::{Hash, Hasher, SipHasher};
 
 use secp256k1::key::SecretKey;
 
@@ -88,7 +88,7 @@ impl AddressIndex {
                     txo: txo.clone(),
                     kind: WalletTxOutType::Unknown
                 };
-                let mut entry = ret.tentative_index.entry(txo.script_pubkey.clone());
+                let entry = ret.tentative_index.entry(txo.script_pubkey.clone());
                 let txos = entry.or_insert(vec![]);
                 txos.push(new);
             }
@@ -101,7 +101,7 @@ impl AddressIndex {
     pub fn index_wallet_txo(&mut self, wtx: &WalletTxOut, kind: WalletTxOutType) {
         let mut new = wtx.clone();
         new.kind = kind;
-        let mut entry = self.index.entry((wtx.txid, wtx.vout));
+        let entry = self.index.entry((wtx.txid, wtx.vout));
         let txos = entry.or_insert(vec![]);
         txos.push(new);
     }
diff --git a/src/wallet/bip32.rs b/src/wallet/bip32.rs
index f51f224..1bfab8c 100644
--- a/src/wallet/bip32.rs
+++ b/src/wallet/bip32.rs
@@ -292,12 +292,12 @@ impl ExtendedPubKey {
 impl ToBase58 for ExtendedPrivKey {
     fn base58_layout(&self) -> Vec<u8> { 
         let mut ret = Vec::with_capacity(78);
-        ret.push_all(&match self.network {
+        ret.extend(match self.network {
             Network::Bitcoin => [0x04, 0x88, 0xAD, 0xE4],
             Network::Testnet => [0x04, 0x35, 0x83, 0x94]
-        });
+        }.iter().cloned());
         ret.push(self.depth as u8);
-        ret.push_all(&self.parent_fingerprint[..]);
+        ret.extend(self.parent_fingerprint[..].iter().cloned());
         let mut be_n = [0; 32];
         match self.child_number {
             ChildNumber::Hardened(n) => {
@@ -307,10 +307,10 @@ impl ToBase58 for ExtendedPrivKey {
                 BigEndian::write_u32(&mut be_n, n);
             }
         }
-        ret.push_all(&be_n);
-        ret.push_all(&self.chain_code[..]);
+        ret.extend(be_n.iter().cloned());
+        ret.extend(self.chain_code[..].iter().cloned());
         ret.push(0);
-        ret.push_all(&self.secret_key[..]);
+        ret.extend(self.secret_key[..].iter().cloned());
         ret
     }
 }
@@ -346,12 +346,12 @@ impl ToBase58 for ExtendedPubKey {
     fn base58_layout(&self) -> Vec<u8> {
         assert!(self.public_key.is_compressed());
         let mut ret = Vec::with_capacity(78);
-        ret.push_all(&match self.network {
+        ret.extend(match self.network {
             Network::Bitcoin => [0x04u8, 0x88, 0xB2, 0x1E],
             Network::Testnet => [0x04u8, 0x35, 0x87, 0xCF]
-        });
+        }.iter().cloned());
         ret.push(self.depth as u8);
-        ret.push_all(&self.parent_fingerprint[..]);
+        ret.extend(self.parent_fingerprint[..].iter().cloned());
         let mut be_n = [0; 32];
         match self.child_number {
             ChildNumber::Hardened(n) => {
@@ -361,9 +361,9 @@ impl ToBase58 for ExtendedPubKey {
                 BigEndian::write_u32(&mut be_n, n);
             }
         }
-        ret.push_all(&be_n);
-        ret.push_all(&self.chain_code[..]);
-        ret.push_all(&self.public_key[..]);
+        ret.extend(be_n.iter().cloned());
+        ret.extend(self.chain_code[..].iter().cloned());
+        ret.extend(self.public_key[..].iter().cloned());
         ret
     }
 }
@@ -524,7 +524,7 @@ mod tests {
         let msk = ExtendedPrivKey::new_master(Bitcoin, &seed).unwrap();
         let mut i = 0;
         bh.iter( || {
-            black_box(msk.ckd_priv(Normal(i)));
+            black_box(msk.ckd_priv(Normal(i)).unwrap());
             i += 1;
         })
     }
@@ -535,7 +535,7 @@ mod tests {
         let msk = ExtendedPrivKey::new_master(Bitcoin, &seed).unwrap();
         let mut i = 0;
         bh.iter( || {
-            black_box(msk.ckd_priv(Hardened(i)));
+            black_box(msk.ckd_priv(Hardened(i)).unwrap());
             i += 1;
         })
     }
@@ -548,7 +548,7 @@ mod tests {
 
         let mut i = 0;
         bh.iter( || {
-            black_box(mpk.ckd_pub(Normal(i)));
+            black_box(mpk.ckd_pub(Normal(i)).unwrap());
             i += 1;
         })
     }
diff --git a/src/wallet/wallet.rs b/src/wallet/wallet.rs
index bed2e0b..36fb08c 100644
--- a/src/wallet/wallet.rs
+++ b/src/wallet/wallet.rs
@@ -88,7 +88,6 @@ pub struct Wallet {
 impl Serialize for Wallet {
     fn serialize<S>(&self, s: &mut S) -> Result<(), S::Error>
             where S: Serializer {
-        let len = self.accounts.len();
         try!(self.master.serialize(s));
         self.accounts.serialize(s)
     }
@@ -176,11 +175,11 @@ impl Wallet {
             AccountChain::Internal => (account.internal_next,
                                        try!(ExtendedPrivKey::from_path(
                                                 &self.master,
-                                                account.internal_path.as_slice()).map_err(Error::Bip32Error))),
+                                                &account.internal_path).map_err(Error::Bip32Error))),
             AccountChain::External => (account.external_next,
                                        try!(ExtendedPrivKey::from_path(
                                                 &self.master,
-                                                account.external_path.as_slice()).map_err(Error::Bip32Error))),
+                                                &account.external_path).map_err(Error::Bip32Error))),
         };
 
         // Scan for next admissible address
@@ -247,7 +246,7 @@ impl Wallet {
         // Sum internal balance
         let master = try!(ExtendedPrivKey::from_path(
                               &self.master,
-                              account.internal_path.as_slice()).map_err(Error::Bip32Error));
+                              &account.internal_path).map_err(Error::Bip32Error));
         for &cnum in account.internal_used.iter() {
             let sk = try!(master.ckd_priv(cnum).map_err(Error::Bip32Error));
             let pk = ExtendedPubKey::from_private(&sk);
@@ -259,7 +258,7 @@ impl Wallet {
         // Sum external balance
         let master = try!(ExtendedPrivKey::from_path(
                               &self.master,
-                              account.external_path.as_slice()).map_err(Error::Bip32Error));
+                              &account.external_path).map_err(Error::Bip32Error));
         for &cnum in account.external_used.iter() {
             let sk = try!(master.ckd_priv(cnum).map_err(Error::Bip32Error));
             let pk = ExtendedPubKey::from_private(&sk);