Merge rust-bitcoin/rust-bitcoin#2262: Clean up `io` usage

f06d12455f bitcoin: Remove the custom sink (Tobin C. Harding)
b503aa1544 Run the formatter (Tobin C. Harding)
3ca55fb163 Remove qualifying path from Read and Write (Tobin C. Harding)
ebeb21fa7a Import fmt::Write using underscore (Tobin C. Harding)
e2dbcb1d28 Use W for writer generic type (Tobin C. Harding)
8704d9f0ae docs: Fix grammar (Tobin C. Harding)

Pull request description:

  A few cleanups to how we use the `io` crate, this is reasonably trivial but commit `a6c7e696 Remove qualifying path from Read and Write` is big, I have however gone to some effort to make sure it is easy to flick through the diff.

  Done in preparation for another go at the `BufRead` stuff.

ACKs for top commit:
  apoelstra:
    ACK f06d12455f
  Kixunil:
    ACK f06d12455f

Tree-SHA512: 751c489c67901c7563f1cc91f7761a4e3c276ae1981010338134e8c13200720ba69fcc74948c1dc1e6e65390197da0da27b2b69b86034029748321b404142cba

bitcoin/src/bip152.rs

@@ -12,6 +12,7 @@ use std::error;
 
 use hashes::{sha256, siphash24, Hash};
 use internals::impl_array_newtype;
+use io::{Read, Write};
 
 use crate::consensus::encode::{self, Decodable, Encodable, VarInt};
 use crate::internal_macros::{impl_bytes_newtype, impl_consensus_encoding};
@@ -73,14 +74,14 @@ impl convert::AsRef<Transaction> for PrefilledTransaction {
 
 impl Encodable for PrefilledTransaction {
     #[inline]
-    fn consensus_encode<W: io::Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
+    fn consensus_encode<W: Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
         Ok(VarInt::from(self.idx).consensus_encode(w)? + self.tx.consensus_encode(w)?)
     }
 }
 
 impl Decodable for PrefilledTransaction {
     #[inline]
-    fn consensus_decode<R: io::Read + ?Sized>(r: &mut R) -> Result<Self, encode::Error> {
+    fn consensus_decode<R: Read + ?Sized>(r: &mut R) -> Result<Self, encode::Error> {
         let idx = VarInt::consensus_decode(r)?.0;
         let idx = u16::try_from(idx)
             .map_err(|_| encode::Error::ParseFailed("BIP152 prefilled tx index out of bounds"))?;
@@ -129,14 +130,14 @@ impl ShortId {
 
 impl Encodable for ShortId {
     #[inline]
-    fn consensus_encode<W: io::Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
+    fn consensus_encode<W: Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
         self.0.consensus_encode(w)
     }
 }
 
 impl Decodable for ShortId {
     #[inline]
-    fn consensus_decode<R: io::Read + ?Sized>(r: &mut R) -> Result<ShortId, encode::Error> {
+    fn consensus_decode<R: Read + ?Sized>(r: &mut R) -> Result<ShortId, encode::Error> {
         Ok(ShortId(Decodable::consensus_decode(r)?))
     }
 }
@@ -258,7 +259,7 @@ impl Encodable for BlockTransactionsRequest {
     ///
     /// Panics if the index overflows [`u64::MAX`]. This happens when [`BlockTransactionsRequest::indexes`]
     /// contains an entry with the value [`u64::MAX`] as `u64` overflows during differential encoding.
-    fn consensus_encode<W: io::Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
+    fn consensus_encode<W: Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
         let mut len = self.block_hash.consensus_encode(w)?;
         // Manually encode indexes because they are differentially encoded VarInts.
         len += VarInt(self.indexes.len() as u64).consensus_encode(w)?;
@@ -272,7 +273,7 @@ impl Encodable for BlockTransactionsRequest {
 }
 
 impl Decodable for BlockTransactionsRequest {
-    fn consensus_decode<R: io::Read + ?Sized>(r: &mut R) -> Result<Self, encode::Error> {
+    fn consensus_decode<R: Read + ?Sized>(r: &mut R) -> Result<Self, encode::Error> {
         Ok(BlockTransactionsRequest {
             block_hash: BlockHash::consensus_decode(r)?,
             indexes: {

bitcoin/src/bip158.rs

@@ -43,6 +43,7 @@ use core::fmt::{self, Display, Formatter};
 
 use hashes::{sha256d, siphash24, Hash};
 use internals::write_err;
+use io::{Read, Write};
 
 use crate::blockdata::block::{Block, BlockHash};
 use crate::blockdata::script::Script;
@@ -175,7 +176,7 @@ pub struct BlockFilterWriter<'a, W> {
     writer: GcsFilterWriter<'a, W>,
 }
 
-impl<'a, W: io::Write> BlockFilterWriter<'a, W> {
+impl<'a, W: Write> BlockFilterWriter<'a, W> {
     /// Creates a new [`BlockFilterWriter`] from `block`.
     pub fn new(writer: &'a mut W, block: &'a Block) -> BlockFilterWriter<'a, W> {
         let block_hash_as_int = block.block_hash().to_byte_array();
@@ -244,7 +245,7 @@ impl BlockFilterReader {
     where
         I: Iterator,
         I::Item: Borrow<[u8]>,
-        R: io::Read + ?Sized,
+        R: Read + ?Sized,
     {
         self.reader.match_any(reader, query)
     }
@@ -254,7 +255,7 @@ impl BlockFilterReader {
     where
         I: Iterator,
         I::Item: Borrow<[u8]>,
-        R: io::Read + ?Sized,
+        R: Read + ?Sized,
     {
         self.reader.match_all(reader, query)
     }
@@ -277,7 +278,7 @@ impl GcsFilterReader {
     where
         I: Iterator,
         I::Item: Borrow<[u8]>,
-        R: io::Read + ?Sized,
+        R: Read + ?Sized,
     {
         let n_elements: VarInt = Decodable::consensus_decode(reader).unwrap_or(VarInt(0));
         // map hashes to [0, n_elements << grp]
@@ -320,7 +321,7 @@ impl GcsFilterReader {
     where
         I: Iterator,
         I::Item: Borrow<[u8]>,
-        R: io::Read + ?Sized,
+        R: Read + ?Sized,
     {
         let n_elements: VarInt = Decodable::consensus_decode(reader).unwrap_or(VarInt(0));
         // map hashes to [0, n_elements << grp]
@@ -371,7 +372,7 @@ pub struct GcsFilterWriter<'a, W> {
     m: u64,
 }
 
-impl<'a, W: io::Write> GcsFilterWriter<'a, W> {
+impl<'a, W: Write> GcsFilterWriter<'a, W> {
     /// Creates a new [`GcsFilterWriter`] wrapping a generic writer, with specific seed to siphash.
     pub fn new(writer: &'a mut W, k0: u64, k1: u64, m: u64, p: u8) -> GcsFilterWriter<'a, W> {
         GcsFilterWriter { filter: GcsFilter::new(k0, k1, p), writer, elements: BTreeSet::new(), m }
@@ -429,7 +430,7 @@ impl GcsFilter {
         n: u64,
     ) -> Result<usize, io::Error>
     where
-        W: io::Write,
+        W: Write,
     {
         let mut wrote = 0;
         let mut q = n >> self.p;
@@ -446,7 +447,7 @@ impl GcsFilter {
     /// Golomb-Rice decodes a number from a bit stream (parameter 2^k).
     fn golomb_rice_decode<R>(&self, reader: &mut BitStreamReader<R>) -> Result<u64, io::Error>
     where
-        R: io::Read + ?Sized,
+        R: Read + ?Sized,
     {
         let mut q = 0u64;
         while reader.read(1)? == 1 {
@@ -469,7 +470,7 @@ pub struct BitStreamReader<'a, R: ?Sized> {
     reader: &'a mut R,
 }
 
-impl<'a, R: io::Read + ?Sized> BitStreamReader<'a, R> {
+impl<'a, R: Read + ?Sized> BitStreamReader<'a, R> {
     /// Creates a new [`BitStreamReader`] that reads bitwise from a given `reader`.
     pub fn new(reader: &'a mut R) -> BitStreamReader<'a, R> {
         BitStreamReader { buffer: [0u8], reader, offset: 8 }
@@ -516,7 +517,7 @@ pub struct BitStreamWriter<'a, W> {
     writer: &'a mut W,
 }
 
-impl<'a, W: io::Write> BitStreamWriter<'a, W> {
+impl<'a, W: Write> BitStreamWriter<'a, W> {
     /// Creates a new [`BitStreamWriter`] that writes bitwise to a given `writer`.
     pub fn new(writer: &'a mut W) -> BitStreamWriter<'a, W> {
         BitStreamWriter { buffer: [0u8], writer, offset: 0 }

bitcoin/src/blockdata/block.rs

@@ -11,6 +11,7 @@
 use core::fmt;
 
 use hashes::{sha256d, Hash, HashEngine};
+use io::{Read, Write};
 
 use super::Weight;
 use crate::blockdata::script;
@@ -200,13 +201,13 @@ impl Default for Version {
 }
 
 impl Encodable for Version {
-    fn consensus_encode<W: io::Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
+    fn consensus_encode<W: Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
         self.0.consensus_encode(w)
     }
 }
 
 impl Decodable for Version {
-    fn consensus_decode<R: io::Read + ?Sized>(r: &mut R) -> Result<Self, encode::Error> {
+    fn consensus_decode<R: Read + ?Sized>(r: &mut R) -> Result<Self, encode::Error> {
         Decodable::consensus_decode(r).map(Version)
     }
 }

bitcoin/src/blockdata/script/mod.rs

@@ -66,6 +66,7 @@ use core::fmt;
 use core::ops::{Deref, DerefMut};
 
 use hashes::{hash160, sha256};
+use io::{Read, Write};
 #[cfg(feature = "serde")]
 use serde;
 
@@ -579,21 +580,21 @@ impl<'de> serde::Deserialize<'de> for ScriptBuf {
 
 impl Encodable for Script {
     #[inline]
-    fn consensus_encode<W: io::Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
+    fn consensus_encode<W: Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
         crate::consensus::encode::consensus_encode_with_size(&self.0, w)
     }
 }
 
 impl Encodable for ScriptBuf {
     #[inline]
-    fn consensus_encode<W: io::Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
+    fn consensus_encode<W: Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
         self.0.consensus_encode(w)
     }
 }
 
 impl Decodable for ScriptBuf {
     #[inline]
-    fn consensus_decode_from_finite_reader<R: io::Read + ?Sized>(
+    fn consensus_decode_from_finite_reader<R: Read + ?Sized>(
         r: &mut R,
     ) -> Result<Self, encode::Error> {
         Ok(ScriptBuf(Decodable::consensus_decode_from_finite_reader(r)?))

bitcoin/src/blockdata/transaction.rs

@@ -16,6 +16,7 @@ use core::{cmp, fmt, str};
 
 use hashes::{self, sha256d, Hash};
 use internals::write_err;
+use io::{Read, Write};
 
 use super::Weight;
 use crate::blockdata::fee_rate::FeeRate;
@@ -1024,13 +1025,13 @@ impl Version {
 }
 
 impl Encodable for Version {
-    fn consensus_encode<W: io::Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
+    fn consensus_encode<W: Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
         self.0.consensus_encode(w)
     }
 }
 
 impl Decodable for Version {
-    fn consensus_decode<R: io::Read + ?Sized>(r: &mut R) -> Result<Self, encode::Error> {
+    fn consensus_decode<R: Read + ?Sized>(r: &mut R) -> Result<Self, encode::Error> {
         Decodable::consensus_decode(r).map(Version)
     }
 }
@@ -1038,13 +1039,13 @@ impl Decodable for Version {
 impl_consensus_encoding!(TxOut, value, script_pubkey);
 
 impl Encodable for OutPoint {
-    fn consensus_encode<W: io::Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
+    fn consensus_encode<W: Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
         let len = self.txid.consensus_encode(w)?;
         Ok(len + self.vout.consensus_encode(w)?)
     }
 }
 impl Decodable for OutPoint {
-    fn consensus_decode<R: io::Read + ?Sized>(r: &mut R) -> Result<Self, encode::Error> {
+    fn consensus_decode<R: Read + ?Sized>(r: &mut R) -> Result<Self, encode::Error> {
         Ok(OutPoint {
             txid: Decodable::consensus_decode(r)?,
             vout: Decodable::consensus_decode(r)?,
@@ -1053,7 +1054,7 @@ impl Decodable for OutPoint {
 }
 
 impl Encodable for TxIn {
-    fn consensus_encode<W: io::Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
+    fn consensus_encode<W: Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
         let mut len = 0;
         len += self.previous_output.consensus_encode(w)?;
         len += self.script_sig.consensus_encode(w)?;
@@ -1063,7 +1064,7 @@ impl Encodable for TxIn {
 }
 impl Decodable for TxIn {
     #[inline]
-    fn consensus_decode_from_finite_reader<R: io::Read + ?Sized>(
+    fn consensus_decode_from_finite_reader<R: Read + ?Sized>(
         r: &mut R,
     ) -> Result<Self, encode::Error> {
         Ok(TxIn {
@@ -1076,19 +1077,19 @@ impl Decodable for TxIn {
 }
 
 impl Encodable for Sequence {
-    fn consensus_encode<W: io::Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
+    fn consensus_encode<W: Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
         self.0.consensus_encode(w)
     }
 }
 
 impl Decodable for Sequence {
-    fn consensus_decode<R: io::Read + ?Sized>(r: &mut R) -> Result<Self, encode::Error> {
+    fn consensus_decode<R: Read + ?Sized>(r: &mut R) -> Result<Self, encode::Error> {
         Decodable::consensus_decode(r).map(Sequence)
     }
 }
 
 impl Encodable for Transaction {
-    fn consensus_encode<W: io::Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
+    fn consensus_encode<W: Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
         let mut len = 0;
         len += self.version.consensus_encode(w)?;
 
@@ -1112,7 +1113,7 @@ impl Encodable for Transaction {
 }
 
 impl Decodable for Transaction {
-    fn consensus_decode_from_finite_reader<R: io::Read + ?Sized>(
+    fn consensus_decode_from_finite_reader<R: Read + ?Sized>(
         r: &mut R,
     ) -> Result<Self, encode::Error> {
         let version = Version::consensus_decode_from_finite_reader(r)?;

bitcoin/src/consensus/encode.rs

@@ -20,7 +20,7 @@ use core::{fmt, mem, u32};
 
 use hashes::{sha256, sha256d, Hash};
 use internals::write_err;
-use io::{Cursor, Read};
+use io::{Cursor, Read, Write};
 
 use crate::bip152::{PrefilledTransaction, ShortId};
 use crate::bip158::{FilterHash, FilterHeader};
@@ -137,7 +137,7 @@ pub fn deserialize_partial<T: Decodable>(data: &[u8]) -> Result<(T, usize), Erro
 }
 
 /// Extensions of `Write` to encode data as per Bitcoin consensus.
-pub trait WriteExt: io::Write {
+pub trait WriteExt: Write {
     /// Outputs a 64-bit unsigned integer.
     fn emit_u64(&mut self, v: u64) -> Result<(), io::Error>;
     /// Outputs a 32-bit unsigned integer.
@@ -164,7 +164,7 @@ pub trait WriteExt: io::Write {
 }
 
 /// Extensions of `Read` to decode data as per Bitcoin consensus.
-pub trait ReadExt: io::Read {
+pub trait ReadExt: Read {
     /// Reads a 64-bit unsigned integer.
     fn read_u64(&mut self) -> Result<u64, Error>;
     /// Reads a 32-bit unsigned integer.
@@ -210,7 +210,7 @@ macro_rules! decoder_fn {
     };
 }
 
-impl<W: io::Write + ?Sized> WriteExt for W {
+impl<W: Write + ?Sized> WriteExt for W {
     encoder_fn!(emit_u64, u64);
     encoder_fn!(emit_u32, u32);
     encoder_fn!(emit_u16, u16);
@@ -267,7 +267,7 @@ pub trait Encodable {
     ///
     /// The number of bytes written on success. The only errors returned are errors propagated from
     /// the writer.
-    fn consensus_encode<W: io::Write + ?Sized>(&self, writer: &mut W) -> Result<usize, io::Error>;
+    fn consensus_encode<W: Write + ?Sized>(&self, writer: &mut W) -> Result<usize, io::Error>;
 }
 
 /// Data which can be encoded in a consensus-consistent way.
@@ -301,7 +301,7 @@ pub trait Decodable: Sized {
     ///   avoid creating redundant `Take` wrappers. Failure to do so might result only in a tiny
     ///   performance hit.
     #[inline]
-    fn consensus_decode_from_finite_reader<R: io::Read + ?Sized>(
+    fn consensus_decode_from_finite_reader<R: Read + ?Sized>(
         reader: &mut R,
     ) -> Result<Self, Error> {
         // This method is always strictly less general than, `consensus_decode`, so it's safe and
@@ -319,7 +319,7 @@ pub trait Decodable: Sized {
     /// for types that override [`Self::consensus_decode_from_finite_reader`]
     /// instead.
     #[inline]
-    fn consensus_decode<R: io::Read + ?Sized>(reader: &mut R) -> Result<Self, Error> {
+    fn consensus_decode<R: Read + ?Sized>(reader: &mut R) -> Result<Self, Error> {
         Self::consensus_decode_from_finite_reader(&mut reader.take(MAX_VEC_SIZE as u64))
     }
 }
@@ -357,16 +357,13 @@ macro_rules! impl_int_encodable {
     ($ty:ident, $meth_dec:ident, $meth_enc:ident) => {
         impl Decodable for $ty {
             #[inline]
-            fn consensus_decode<R: io::Read + ?Sized>(r: &mut R) -> Result<Self, Error> {
+            fn consensus_decode<R: Read + ?Sized>(r: &mut R) -> Result<Self, Error> {
                 ReadExt::$meth_dec(r)
             }
         }
         impl Encodable for $ty {
             #[inline]
-            fn consensus_encode<W: io::Write + ?Sized>(
+            fn consensus_encode<W: Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
-                &self,
-                w: &mut W,
-            ) -> Result<usize, io::Error> {
                 w.$meth_enc(*self)?;
                 Ok(mem::size_of::<$ty>())
             }
@@ -416,7 +413,7 @@ impl_var_int_from!(u8, u16, u32, u64, usize);
 
 impl Encodable for VarInt {
     #[inline]
-    fn consensus_encode<W: io::Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
+    fn consensus_encode<W: Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
         match self.0 {
             0..=0xFC => {
                 (self.0 as u8).consensus_encode(w)?;
@@ -443,7 +440,7 @@ impl Encodable for VarInt {
 
 impl Decodable for VarInt {
     #[inline]
-    fn consensus_decode<R: io::Read + ?Sized>(r: &mut R) -> Result<Self, Error> {
+    fn consensus_decode<R: Read + ?Sized>(r: &mut R) -> Result<Self, Error> {
         let n = ReadExt::read_u8(r)?;
         match n {
             0xFF => {
@@ -477,7 +474,7 @@ impl Decodable for VarInt {
 
 impl Encodable for bool {
     #[inline]
-    fn consensus_encode<W: io::Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
+    fn consensus_encode<W: Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
         w.emit_bool(*self)?;
         Ok(1)
     }
@@ -485,14 +482,14 @@ impl Encodable for bool {
 
 impl Decodable for bool {
     #[inline]
-    fn consensus_decode<R: io::Read + ?Sized>(r: &mut R) -> Result<bool, Error> {
+    fn consensus_decode<R: Read + ?Sized>(r: &mut R) -> Result<bool, Error> {
         ReadExt::read_bool(r)
     }
 }
 
 impl Encodable for String {
     #[inline]
-    fn consensus_encode<W: io::Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
+    fn consensus_encode<W: Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
         let b = self.as_bytes();
         let vi_len = VarInt(b.len() as u64).consensus_encode(w)?;
         w.emit_slice(b)?;
@@ -502,7 +499,7 @@ impl Encodable for String {
 
 impl Decodable for String {
     #[inline]
-    fn consensus_decode<R: io::Read + ?Sized>(r: &mut R) -> Result<String, Error> {
+    fn consensus_decode<R: Read + ?Sized>(r: &mut R) -> Result<String, Error> {
         String::from_utf8(Decodable::consensus_decode(r)?)
             .map_err(|_| self::Error::ParseFailed("String was not valid UTF8"))
     }
@@ -510,7 +507,7 @@ impl Decodable for String {
 
 impl Encodable for Cow<'static, str> {
     #[inline]
-    fn consensus_encode<W: io::Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
+    fn consensus_encode<W: Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
         let b = self.as_bytes();
         let vi_len = VarInt(b.len() as u64).consensus_encode(w)?;
         w.emit_slice(b)?;
@@ -520,7 +517,7 @@ impl Encodable for Cow<'static, str> {
 
 impl Decodable for Cow<'static, str> {
     #[inline]
-    fn consensus_decode<R: io::Read + ?Sized>(r: &mut R) -> Result<Cow<'static, str>, Error> {
+    fn consensus_decode<R: Read + ?Sized>(r: &mut R) -> Result<Cow<'static, str>, Error> {
         String::from_utf8(Decodable::consensus_decode(r)?)
             .map_err(|_| self::Error::ParseFailed("String was not valid UTF8"))
             .map(Cow::Owned)
@@ -542,7 +539,7 @@ macro_rules! impl_array {
 
         impl Decodable for [u8; $size] {
             #[inline]
-            fn consensus_decode<R: io::Read + ?Sized>(r: &mut R) -> Result<Self, Error> {
+            fn consensus_decode<R: Read + ?Sized>(r: &mut R) -> Result<Self, Error> {
                 let mut ret = [0; $size];
                 r.read_slice(&mut ret)?;
                 Ok(ret)
@@ -563,7 +560,7 @@ impl_array!(33);
 
 impl Decodable for [u16; 8] {
     #[inline]
-    fn consensus_decode<R: io::Read + ?Sized>(r: &mut R) -> Result<Self, Error> {
+    fn consensus_decode<R: Read + ?Sized>(r: &mut R) -> Result<Self, Error> {
         let mut res = [0; 8];
         for item in &mut res {
             *item = Decodable::consensus_decode(r)?;
@@ -574,7 +571,7 @@ impl Decodable for [u16; 8] {
 
 impl Encodable for [u16; 8] {
     #[inline]
-    fn consensus_encode<W: io::Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
+    fn consensus_encode<W: Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
         for c in self.iter() {
             c.consensus_encode(w)?;
         }
@@ -586,10 +583,7 @@ macro_rules! impl_vec {
     ($type: ty) => {
         impl Encodable for Vec<$type> {
             #[inline]
-            fn consensus_encode<W: io::Write + ?Sized>(
+            fn consensus_encode<W: Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
-                &self,
-                w: &mut W,
-            ) -> Result<usize, io::Error> {
                 let mut len = 0;
                 len += VarInt(self.len() as u64).consensus_encode(w)?;
                 for c in self.iter() {
@@ -601,7 +595,7 @@ macro_rules! impl_vec {
 
         impl Decodable for Vec<$type> {
             #[inline]
-            fn consensus_decode_from_finite_reader<R: io::Read + ?Sized>(
+            fn consensus_decode_from_finite_reader<R: Read + ?Sized>(
                 r: &mut R,
             ) -> Result<Self, Error> {
                 let len = VarInt::consensus_decode_from_finite_reader(r)?.0;
@@ -643,7 +637,7 @@ impl_vec!((u32, Address));
 #[cfg(feature = "std")]
 impl_vec!(AddrV2Message);
 
-pub(crate) fn consensus_encode_with_size<W: io::Write + ?Sized>(
+pub(crate) fn consensus_encode_with_size<W: Write + ?Sized>(
     data: &[u8],
     w: &mut W,
 ) -> Result<usize, io::Error> {
@@ -662,7 +656,7 @@ struct ReadBytesFromFiniteReaderOpts {
 /// This function relies on reader being bound in amount of data
 /// it returns for OOM protection. See [`Decodable::consensus_decode_from_finite_reader`].
 #[inline]
-fn read_bytes_from_finite_reader<D: io::Read + ?Sized>(
+fn read_bytes_from_finite_reader<D: Read + ?Sized>(
     d: &mut D,
     mut opts: ReadBytesFromFiniteReaderOpts,
 ) -> Result<Vec<u8>, Error> {
@@ -684,14 +678,14 @@ fn read_bytes_from_finite_reader<D: io::Read + ?Sized>(
 
 impl Encodable for Vec<u8> {
     #[inline]
-    fn consensus_encode<W: io::Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
+    fn consensus_encode<W: Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
         consensus_encode_with_size(self, w)
     }
 }
 
 impl Decodable for Vec<u8> {
     #[inline]
-    fn consensus_decode_from_finite_reader<R: io::Read + ?Sized>(r: &mut R) -> Result<Self, Error> {
+    fn consensus_decode_from_finite_reader<R: Read + ?Sized>(r: &mut R) -> Result<Self, Error> {
         let len = VarInt::consensus_decode(r)?.0 as usize;
         // most real-world vec of bytes data, wouldn't be larger than 128KiB
         let opts = ReadBytesFromFiniteReaderOpts { len, chunk_size: 128 * 1024 };
@@ -701,14 +695,14 @@ impl Decodable for Vec<u8> {
 
 impl Encodable for Box<[u8]> {
     #[inline]
-    fn consensus_encode<W: io::Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
+    fn consensus_encode<W: Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
         consensus_encode_with_size(self, w)
     }
 }
 
 impl Decodable for Box<[u8]> {
     #[inline]
-    fn consensus_decode_from_finite_reader<R: io::Read + ?Sized>(r: &mut R) -> Result<Self, Error> {
+    fn consensus_decode_from_finite_reader<R: Read + ?Sized>(r: &mut R) -> Result<Self, Error> {
         <Vec<u8>>::consensus_decode_from_finite_reader(r).map(From::from)
     }
 }
@@ -721,7 +715,7 @@ fn sha2_checksum(data: &[u8]) -> [u8; 4] {
 
 impl Encodable for CheckedData {
     #[inline]
-    fn consensus_encode<W: io::Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
+    fn consensus_encode<W: Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
         u32::try_from(self.data.len())
             .expect("network message use u32 as length")
             .consensus_encode(w)?;
@@ -733,7 +727,7 @@ impl Encodable for CheckedData {
 
 impl Decodable for CheckedData {
     #[inline]
-    fn consensus_decode_from_finite_reader<R: io::Read + ?Sized>(r: &mut R) -> Result<Self, Error> {
+    fn consensus_decode_from_finite_reader<R: Read + ?Sized>(r: &mut R) -> Result<Self, Error> {
         let len = u32::consensus_decode_from_finite_reader(r)? as usize;
 
         let checksum = <[u8; 4]>::consensus_decode_from_finite_reader(r)?;
@@ -749,19 +743,19 @@ impl Decodable for CheckedData {
 }
 
 impl<'a, T: Encodable> Encodable for &'a T {
-    fn consensus_encode<W: io::Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
+    fn consensus_encode<W: Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
         (**self).consensus_encode(w)
     }
 }
 
 impl<'a, T: Encodable> Encodable for &'a mut T {
-    fn consensus_encode<W: io::Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
+    fn consensus_encode<W: Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
         (**self).consensus_encode(w)
     }
 }
 
 impl<T: Encodable> Encodable for rc::Rc<T> {
-    fn consensus_encode<W: io::Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
+    fn consensus_encode<W: Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
         (**self).consensus_encode(w)
     }
 }
@@ -769,7 +763,7 @@ impl<T: Encodable> Encodable for rc::Rc<T> {
 /// Note: This will fail to compile on old Rust for targets that don't support atomics
 #[cfg(any(not(rust_v_1_60), target_has_atomic = "ptr"))]
 impl<T: Encodable> Encodable for sync::Arc<T> {
-    fn consensus_encode<W: io::Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
+    fn consensus_encode<W: Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
         (**self).consensus_encode(w)
     }
 }
@@ -779,7 +773,7 @@ macro_rules! tuple_encode {
         impl <$($x: Encodable),*> Encodable for ($($x),*) {
             #[inline]
             #[allow(non_snake_case)]
-            fn consensus_encode<W: io::Write + ?Sized>(
+            fn consensus_encode<W: Write + ?Sized>(
                 &self,
                 w: &mut W,
             ) -> Result<usize, io::Error> {
@@ -793,7 +787,7 @@ macro_rules! tuple_encode {
         impl<$($x: Decodable),*> Decodable for ($($x),*) {
             #[inline]
             #[allow(non_snake_case)]
-            fn consensus_decode<R: io::Read + ?Sized>(r: &mut R) -> Result<Self, Error> {
+            fn consensus_decode<R: Read + ?Sized>(r: &mut R) -> Result<Self, Error> {
                 Ok(($({let $x = Decodable::consensus_decode(r)?; $x }),*))
             }
         }
@@ -809,37 +803,37 @@ tuple_encode!(T0, T1, T2, T3, T4, T5, T6);
 tuple_encode!(T0, T1, T2, T3, T4, T5, T6, T7);
 
 impl Encodable for sha256d::Hash {
-    fn consensus_encode<W: io::Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
+    fn consensus_encode<W: Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
         self.as_byte_array().consensus_encode(w)
     }
 }
 
 impl Decodable for sha256d::Hash {
-    fn consensus_decode<R: io::Read + ?Sized>(r: &mut R) -> Result<Self, Error> {
+    fn consensus_decode<R: Read + ?Sized>(r: &mut R) -> Result<Self, Error> {
         Ok(Self::from_byte_array(<<Self as Hash>::Bytes>::consensus_decode(r)?))
     }
 }
 
 impl Encodable for sha256::Hash {
-    fn consensus_encode<W: io::Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
+    fn consensus_encode<W: Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
         self.as_byte_array().consensus_encode(w)
     }
 }
 
 impl Decodable for sha256::Hash {
-    fn consensus_decode<R: io::Read + ?Sized>(r: &mut R) -> Result<Self, Error> {
+    fn consensus_decode<R: Read + ?Sized>(r: &mut R) -> Result<Self, Error> {
         Ok(Self::from_byte_array(<<Self as Hash>::Bytes>::consensus_decode(r)?))
     }
 }
 
 impl Encodable for TapLeafHash {
-    fn consensus_encode<W: io::Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
+    fn consensus_encode<W: Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
         self.as_byte_array().consensus_encode(w)
     }
 }
 
 impl Decodable for TapLeafHash {
-    fn consensus_decode<R: io::Read + ?Sized>(r: &mut R) -> Result<Self, Error> {
+    fn consensus_decode<R: Read + ?Sized>(r: &mut R) -> Result<Self, Error> {
         Ok(Self::from_byte_array(<<Self as Hash>::Bytes>::consensus_decode(r)?))
     }
 }

bitcoin/src/consensus/serde.rs

@@ -12,6 +12,7 @@
 use core::fmt;
 use core::marker::PhantomData;
 
+use io::{Read, Write};
 use serde::de::{SeqAccess, Unexpected, Visitor};
 use serde::ser::SerializeSeq;
 use serde::{Deserializer, Serializer};
@@ -268,7 +269,7 @@ impl<'a, W: fmt::Write, E: EncodeBytes> IoWrapper<'a, W, E> {
     fn actually_flush(&mut self) -> fmt::Result { self.encoder.flush(&mut self.writer) }
 }
 
-impl<'a, W: fmt::Write, E: EncodeBytes> io::Write for IoWrapper<'a, W, E> {
+impl<'a, W: fmt::Write, E: EncodeBytes> Write for IoWrapper<'a, W, E> {
     fn write(&mut self, bytes: &[u8]) -> io::Result<usize> {
         match self.encoder.encode_chunk(&mut self.writer, bytes) {
             Ok(()) => Ok(bytes.len()),
@@ -338,7 +339,7 @@ struct BinWriter<S: SerializeSeq> {
     error: Option<S::Error>,
 }
 
-impl<S: SerializeSeq> io::Write for BinWriter<S> {
+impl<S: SerializeSeq> Write for BinWriter<S> {
     fn write(&mut self, buf: &[u8]) -> io::Result<usize> { self.write_all(buf).map(|_| buf.len()) }
 
     fn write_all(&mut self, buf: &[u8]) -> io::Result<()> {
@@ -441,7 +442,7 @@ impl<E: fmt::Debug, I: Iterator<Item = Result<u8, E>>> IterReader<E, I> {
     }
 }
 
-impl<E: fmt::Debug, I: Iterator<Item = Result<u8, E>>> io::Read for IterReader<E, I> {
+impl<E: fmt::Debug, I: Iterator<Item = Result<u8, E>>> Read for IterReader<E, I> {
     fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
         let mut count = 0;
         for (dst, src) in buf.iter_mut().zip(&mut self.iterator) {

bitcoin/src/crypto/key.rs

@@ -5,13 +5,14 @@
 //! This module provides keys used in Bitcoin that can be roundtrip
 //! (de)serialized.
 
-use core::fmt::{self, Write};
+use core::fmt::{self, Write as _};
 use core::ops;
 use core::str::FromStr;
 
 use hashes::{hash160, Hash};
 use hex::FromHex;
 use internals::write_err;
+use io::{Read, Write};
 
 use crate::crypto::ecdsa;
 use crate::internal_macros::impl_asref_push_bytes;
@@ -70,7 +71,7 @@ impl PublicKey {
     }
 
     /// Write the public key into a writer
-    pub fn write_into<W: io::Write + ?Sized>(&self, writer: &mut W) -> Result<(), io::Error> {
+    pub fn write_into<W: Write + ?Sized>(&self, writer: &mut W) -> Result<(), io::Error> {
         self.with_serialized(|bytes| writer.write_all(bytes))
     }
 
@@ -78,7 +79,7 @@ impl PublicKey {
     ///
     /// This internally reads the first byte before reading the rest, so
     /// use of a `BufReader` is recommended.
-    pub fn read_from<R: io::Read + ?Sized>(reader: &mut R) -> Result<Self, io::Error> {
+    pub fn read_from<R: Read + ?Sized>(reader: &mut R) -> Result<Self, io::Error> {
         let mut bytes = [0; 65];
 
         reader.read_exact(&mut bytes[0..1])?;

bitcoin/src/crypto/sighash.rs

@@ -16,12 +16,13 @@ use core::{fmt, str};
 
 use hashes::{hash_newtype, sha256, sha256d, sha256t_hash_newtype, Hash};
 use internals::write_err;
+use io::Write;
 
 use crate::blockdata::witness::Witness;
 use crate::consensus::{encode, Encodable};
 use crate::prelude::*;
 use crate::taproot::{LeafVersion, TapLeafHash, TAPROOT_ANNEX_PREFIX};
-use crate::{io, Amount, Script, ScriptBuf, Sequence, Transaction, TxIn, TxOut};
+use crate::{Amount, Script, ScriptBuf, Sequence, Transaction, TxIn, TxOut};
 
 /// Used for signature hash for invalid use of SIGHASH_SINGLE.
 #[rustfmt::skip]
@@ -671,11 +672,11 @@ impl<R: Borrow<Transaction>> SighashCache<R> {
     /// Destroys the cache and recovers the stored transaction.
     pub fn into_transaction(self) -> R { self.tx }
 
-    /// Encodes the BIP341 signing data for any flag type into a given object implementing a
+    /// Encodes the BIP341 signing data for any flag type into a given object implementing the
     /// [`io::Write`] trait.
-    pub fn taproot_encode_signing_data_to<Write: io::Write + ?Sized, T: Borrow<TxOut>>(
+    pub fn taproot_encode_signing_data_to<W: Write + ?Sized, T: Borrow<TxOut>>(
         &mut self,
-        writer: &mut Write,
+        writer: &mut W,
         input_index: usize,
         prevouts: &Prevouts<T>,
         annex: Option<Annex>,
@@ -854,15 +855,15 @@ impl<R: Borrow<Transaction>> SighashCache<R> {
         Ok(TapSighash::from_engine(enc))
     }
 
-    /// Encodes the BIP143 signing data for any flag type into a given object implementing a
+    /// Encodes the BIP143 signing data for any flag type into a given object implementing the
     /// [`std::io::Write`] trait.
     ///
     /// `script_code` is dependent on the type of the spend transaction. For p2wpkh use
     /// [`Script::p2wpkh_script_code`], for p2wsh just pass in the witness script. (Also see
     /// [`Self::p2wpkh_signature_hash`] and [`SighashCache::p2wsh_signature_hash`].)
-    pub fn segwit_v0_encode_signing_data_to<Write: io::Write + ?Sized>(
+    pub fn segwit_v0_encode_signing_data_to<W: Write + ?Sized>(
         &mut self,
-        writer: &mut Write,
+        writer: &mut W,
         input_index: usize,
         script_code: &Script,
         value: Amount,
@@ -984,9 +985,9 @@ impl<R: Borrow<Transaction>> SighashCache<R> {
     ///
     /// This function can't handle the SIGHASH_SINGLE bug internally, so it returns [`EncodeSigningDataResult`]
     /// that must be handled by the caller (see [`EncodeSigningDataResult::is_sighash_single_bug`]).
-    pub fn legacy_encode_signing_data_to<Write: io::Write + ?Sized, U: Into<u32>>(
+    pub fn legacy_encode_signing_data_to<W: Write + ?Sized, U: Into<u32>>(
         &self,
-        writer: &mut Write,
+        writer: &mut W,
         input_index: usize,
         script_pubkey: &Script,
         sighash_type: U,
@@ -1011,9 +1012,9 @@ impl<R: Borrow<Transaction>> SighashCache<R> {
             return EncodeSigningDataResult::SighashSingleBug;
         }
 
-        fn encode_signing_data_to_inner<Write: io::Write + ?Sized>(
+        fn encode_signing_data_to_inner<W: Write + ?Sized>(
             self_: &Transaction,
-            writer: &mut Write,
+            writer: &mut W,
             input_index: usize,
             script_pubkey: &Script,
             sighash_type: u32,
@@ -1239,7 +1240,7 @@ impl<'a> Annex<'a> {
 }
 
 impl<'a> Encodable for Annex<'a> {
-    fn consensus_encode<W: io::Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
+    fn consensus_encode<W: Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
         encode::consensus_encode_with_size(self.0, w)
     }
 }

bitcoin/src/lib.rs

@@ -140,27 +140,6 @@ pub use crate::{
     taproot::{TapBranchTag, TapLeafHash, TapLeafTag, TapNodeHash, TapTweakHash, TapTweakTag},
 };
 
-#[cfg(not(feature = "std"))]
-mod io_extras {
-    use crate::io;
-
-    /// A writer which will move data into the void.
-    pub struct Sink {
-        _priv: (),
-    }
-
-    /// Creates an instance of a writer which will successfully consume all data.
-    pub const fn sink() -> Sink { Sink { _priv: () } }
-
-    impl io::Write for Sink {
-        #[inline]
-        fn write(&mut self, buf: &[u8]) -> io::Result<usize> { Ok(buf.len()) }
-
-        #[inline]
-        fn flush(&mut self) -> io::Result<()> { Ok(()) }
-    }
-}
-
 #[rustfmt::skip]
 mod prelude {
     #[cfg(all(not(feature = "std"), not(test)))]
@@ -178,12 +157,8 @@ mod prelude {
     #[cfg(any(feature = "std", test))]
     pub use std::collections::{BTreeMap, BTreeSet, btree_map, BinaryHeap};
 
-    #[cfg(feature = "std")]
     pub use crate::io::sink;
 
-    #[cfg(not(feature = "std"))]
-    pub use crate::io_extras::sink;
-
     pub use hex::DisplayHex;
 }
 

bitcoin/src/merkle_tree/block.rs

@@ -41,6 +41,7 @@
 use core::fmt;
 
 use hashes::Hash;
+use io::{Read, Write};
 
 use self::MerkleBlockError::*;
 use crate::blockdata::block::{self, Block, TxMerkleNode};
@@ -143,14 +144,14 @@ impl MerkleBlock {
 }
 
 impl Encodable for MerkleBlock {
-    fn consensus_encode<W: io::Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
+    fn consensus_encode<W: Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
         let len = self.header.consensus_encode(w)? + self.txn.consensus_encode(w)?;
         Ok(len)
     }
 }
 
 impl Decodable for MerkleBlock {
-    fn consensus_decode<R: io::Read + ?Sized>(r: &mut R) -> Result<Self, encode::Error> {
+    fn consensus_decode<R: Read + ?Sized>(r: &mut R) -> Result<Self, encode::Error> {
         Ok(MerkleBlock {
             header: Decodable::consensus_decode(r)?,
             txn: Decodable::consensus_decode(r)?,
@@ -433,7 +434,7 @@ impl PartialMerkleTree {
 }
 
 impl Encodable for PartialMerkleTree {
-    fn consensus_encode<W: io::Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
+    fn consensus_encode<W: Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
         let mut ret = self.num_transactions.consensus_encode(w)?;
         ret += self.hashes.consensus_encode(w)?;
 
@@ -451,7 +452,7 @@ impl Encodable for PartialMerkleTree {
 }
 
 impl Decodable for PartialMerkleTree {
-    fn consensus_decode_from_finite_reader<R: io::Read + ?Sized>(
+    fn consensus_decode_from_finite_reader<R: Read + ?Sized>(
         r: &mut R,
     ) -> Result<Self, encode::Error> {
         let num_transactions: u32 = Decodable::consensus_decode(r)?;

bitcoin/src/merkle_tree/mod.rs

@@ -19,6 +19,7 @@ use core::cmp::min;
 use core::iter;
 
 use hashes::Hash;
+use io::Write;
 
 use crate::consensus::encode::Encodable;
 use crate::prelude::*;
@@ -40,7 +41,7 @@ pub use self::block::{MerkleBlock, MerkleBlockError, PartialMerkleTree};
 pub fn calculate_root_inline<T>(hashes: &mut [T]) -> Option<T>
 where
     T: Hash + Encodable,
-    <T as Hash>::Engine: io::Write,
+    <T as Hash>::Engine: Write,
 {
     match hashes.len() {
         0 => None,
@@ -58,7 +59,7 @@ where
 pub fn calculate_root<T, I>(mut hashes: I) -> Option<T>
 where
     T: Hash + Encodable,
-    <T as Hash>::Engine: io::Write,
+    <T as Hash>::Engine: Write,
     I: Iterator<Item = T>,
 {
     let first = hashes.next()?;
@@ -90,7 +91,7 @@ where
 fn merkle_root_r<T>(hashes: &mut [T]) -> T
 where
     T: Hash + Encodable,
-    <T as Hash>::Engine: io::Write,
+    <T as Hash>::Engine: Write,
 {
     if hashes.len() == 1 {
         return hashes[0];

bitcoin/src/p2p/address.rs

@@ -9,6 +9,8 @@
 use core::{fmt, iter};
 use std::net::{Ipv4Addr, Ipv6Addr, SocketAddr, SocketAddrV4, SocketAddrV6, ToSocketAddrs};
 
+use io::{Read, Write};
+
 use crate::consensus::encode::{self, Decodable, Encodable, ReadExt, VarInt, WriteExt};
 use crate::p2p::ServiceFlags;
 use crate::prelude::*;
@@ -56,7 +58,7 @@ impl Address {
 
 impl Encodable for Address {
     #[inline]
-    fn consensus_encode<W: io::Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
+    fn consensus_encode<W: Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
         let mut len = self.services.consensus_encode(w)?;
 
         for word in &self.address {
@@ -73,7 +75,7 @@ impl Encodable for Address {
 
 impl Decodable for Address {
     #[inline]
-    fn consensus_decode<R: io::Read + ?Sized>(r: &mut R) -> Result<Self, encode::Error> {
+    fn consensus_decode<R: Read + ?Sized>(r: &mut R) -> Result<Self, encode::Error> {
         Ok(Address {
             services: Decodable::consensus_decode(r)?,
             address: read_be_address(r)?,
@@ -83,12 +85,12 @@ impl Decodable for Address {
 }
 
 /// Read a big-endian address from reader.
-fn read_be_address<R: io::Read + ?Sized>(r: &mut R) -> Result<[u16; 8], encode::Error> {
+fn read_be_address<R: Read + ?Sized>(r: &mut R) -> Result<[u16; 8], encode::Error> {
     let mut address = [0u16; 8];
     let mut buf = [0u8; 2];
 
     for word in &mut address {
-        io::Read::read_exact(r, &mut buf)?;
+        Read::read_exact(r, &mut buf)?;
         *word = u16::from_be_bytes(buf)
     }
     Ok(address)
@@ -140,8 +142,8 @@ pub enum AddrV2 {
 }
 
 impl Encodable for AddrV2 {
-    fn consensus_encode<W: io::Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
+    fn consensus_encode<W: Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
-        fn encode_addr<W: io::Write + ?Sized>(
+        fn encode_addr<W: Write + ?Sized>(
             w: &mut W,
             network: u8,
             bytes: &[u8],
@@ -165,7 +167,7 @@ impl Encodable for AddrV2 {
 }
 
 impl Decodable for AddrV2 {
-    fn consensus_decode<R: io::Read + ?Sized>(r: &mut R) -> Result<Self, encode::Error> {
+    fn consensus_decode<R: Read + ?Sized>(r: &mut R) -> Result<Self, encode::Error> {
         let network_id = u8::consensus_decode(r)?;
         let len = VarInt::consensus_decode(r)?.0;
         if len > 512 {
@@ -269,7 +271,7 @@ impl AddrV2Message {
 }
 
 impl Encodable for AddrV2Message {
-    fn consensus_encode<W: io::Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
+    fn consensus_encode<W: Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
         let mut len = 0;
         len += self.time.consensus_encode(w)?;
         len += VarInt(self.services.to_u64()).consensus_encode(w)?;
@@ -283,7 +285,7 @@ impl Encodable for AddrV2Message {
 }
 
 impl Decodable for AddrV2Message {
-    fn consensus_decode<R: io::Read + ?Sized>(r: &mut R) -> Result<Self, encode::Error> {
+    fn consensus_decode<R: Read + ?Sized>(r: &mut R) -> Result<Self, encode::Error> {
         Ok(AddrV2Message {
             time: Decodable::consensus_decode(r)?,
             services: ServiceFlags::from(VarInt::consensus_decode(r)?.0),

bitcoin/src/p2p/message.rs

@@ -9,6 +9,7 @@
 use core::{fmt, iter};
 
 use hashes::{sha256d, Hash};
+use io::{Read, Write};
 
 use crate::blockdata::{block, transaction};
 use crate::consensus::encode::{self, CheckedData, Decodable, Encodable, VarInt};
@@ -98,7 +99,7 @@ impl AsRef<str> for CommandString {
 
 impl Encodable for CommandString {
     #[inline]
-    fn consensus_encode<W: io::Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
+    fn consensus_encode<W: Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
         let mut rawbytes = [0u8; 12];
         let strbytes = self.0.as_bytes();
         debug_assert!(strbytes.len() <= 12);
@@ -109,7 +110,7 @@ impl Encodable for CommandString {
 
 impl Decodable for CommandString {
     #[inline]
-    fn consensus_decode<R: io::Read + ?Sized>(r: &mut R) -> Result<Self, encode::Error> {
+    fn consensus_decode<R: Read + ?Sized>(r: &mut R) -> Result<Self, encode::Error> {
         let rawbytes: [u8; 12] = Decodable::consensus_decode(r)?;
         let rv = iter::FromIterator::from_iter(rawbytes.iter().filter_map(|&u| {
             if u > 0 {
@@ -334,7 +335,7 @@ struct HeaderSerializationWrapper<'a>(&'a Vec<block::Header>);
 
 impl<'a> Encodable for HeaderSerializationWrapper<'a> {
     #[inline]
-    fn consensus_encode<W: io::Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
+    fn consensus_encode<W: Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
         let mut len = 0;
         len += VarInt::from(self.0.len()).consensus_encode(w)?;
         for header in self.0.iter() {
@@ -346,7 +347,7 @@ impl<'a> Encodable for HeaderSerializationWrapper<'a> {
 }
 
 impl Encodable for NetworkMessage {
-    fn consensus_encode<W: io::Write + ?Sized>(&self, writer: &mut W) -> Result<usize, io::Error> {
+    fn consensus_encode<W: Write + ?Sized>(&self, writer: &mut W) -> Result<usize, io::Error> {
         match self {
             NetworkMessage::Version(ref dat) => dat.consensus_encode(writer),
             NetworkMessage::Addr(ref dat) => dat.consensus_encode(writer),
@@ -391,7 +392,7 @@ impl Encodable for NetworkMessage {
 }
 
 impl Encodable for RawNetworkMessage {
-    fn consensus_encode<W: io::Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
+    fn consensus_encode<W: Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
         let mut len = 0;
         len += self.magic.consensus_encode(w)?;
         len += self.command().consensus_encode(w)?;
@@ -406,7 +407,7 @@ struct HeaderDeserializationWrapper(Vec<block::Header>);
 
 impl Decodable for HeaderDeserializationWrapper {
     #[inline]
-    fn consensus_decode_from_finite_reader<R: io::Read + ?Sized>(
+    fn consensus_decode_from_finite_reader<R: Read + ?Sized>(
         r: &mut R,
     ) -> Result<Self, encode::Error> {
         let len = VarInt::consensus_decode(r)?.0;
@@ -425,13 +426,13 @@ impl Decodable for HeaderDeserializationWrapper {
     }
 
     #[inline]
-    fn consensus_decode<R: io::Read + ?Sized>(r: &mut R) -> Result<Self, encode::Error> {
+    fn consensus_decode<R: Read + ?Sized>(r: &mut R) -> Result<Self, encode::Error> {
         Self::consensus_decode_from_finite_reader(&mut r.take(MAX_MSG_SIZE as u64))
     }
 }
 
 impl Decodable for RawNetworkMessage {
-    fn consensus_decode_from_finite_reader<R: io::Read + ?Sized>(
+    fn consensus_decode_from_finite_reader<R: Read + ?Sized>(
         r: &mut R,
     ) -> Result<Self, encode::Error> {
         let magic = Decodable::consensus_decode_from_finite_reader(r)?;
@@ -530,7 +531,7 @@ impl Decodable for RawNetworkMessage {
     }
 
     #[inline]
-    fn consensus_decode<R: io::Read + ?Sized>(r: &mut R) -> Result<Self, encode::Error> {
+    fn consensus_decode<R: Read + ?Sized>(r: &mut R) -> Result<Self, encode::Error> {
         Self::consensus_decode_from_finite_reader(&mut r.take(MAX_MSG_SIZE as u64))
     }
 }

bitcoin/src/p2p/message_blockdata.rs

@@ -7,6 +7,7 @@
 //!
 
 use hashes::{sha256d, Hash as _};
+use io::{Read, Write};
 
 use crate::blockdata::block::BlockHash;
 use crate::blockdata::transaction::{Txid, Wtxid};
@@ -61,7 +62,7 @@ impl Inventory {
 
 impl Encodable for Inventory {
     #[inline]
-    fn consensus_encode<W: io::Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
+    fn consensus_encode<W: Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
         macro_rules! encode_inv {
             ($code:expr, $item:expr) => {
                 u32::consensus_encode(&$code, w)? + $item.consensus_encode(w)?
@@ -82,7 +83,7 @@ impl Encodable for Inventory {
 
 impl Decodable for Inventory {
     #[inline]
-    fn consensus_decode<R: io::Read + ?Sized>(r: &mut R) -> Result<Self, encode::Error> {
+    fn consensus_decode<R: Read + ?Sized>(r: &mut R) -> Result<Self, encode::Error> {
         let inv_type: u32 = Decodable::consensus_decode(r)?;
         Ok(match inv_type {
             0 => Inventory::Error,

bitcoin/src/p2p/message_bloom.rs

@@ -5,6 +5,8 @@
 //! This module describes BIP37 Connection Bloom filtering network messages.
 //!
 
+use io::{Read, Write};
+
 use crate::consensus::{encode, Decodable, Encodable, ReadExt};
 use crate::internal_macros::impl_consensus_encoding;
 
@@ -35,7 +37,7 @@ pub enum BloomFlags {
 }
 
 impl Encodable for BloomFlags {
-    fn consensus_encode<W: io::Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
+    fn consensus_encode<W: Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
         w.write_all(&[match self {
             BloomFlags::None => 0,
             BloomFlags::All => 1,
@@ -46,7 +48,7 @@ impl Encodable for BloomFlags {
 }
 
 impl Decodable for BloomFlags {
-    fn consensus_decode<R: io::Read + ?Sized>(r: &mut R) -> Result<Self, encode::Error> {
+    fn consensus_decode<R: Read + ?Sized>(r: &mut R) -> Result<Self, encode::Error> {
         Ok(match r.read_u8()? {
             0 => BloomFlags::None,
             1 => BloomFlags::All,

bitcoin/src/p2p/message_network.rs

@@ -7,6 +7,7 @@
 //!
 
 use hashes::sha256d;
+use io::{Read, Write};
 
 use crate::consensus::{encode, Decodable, Encodable, ReadExt};
 use crate::internal_macros::impl_consensus_encoding;
@@ -102,14 +103,14 @@ pub enum RejectReason {
 }
 
 impl Encodable for RejectReason {
-    fn consensus_encode<W: io::Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
+    fn consensus_encode<W: Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
         w.write_all(&[*self as u8])?;
         Ok(1)
     }
 }
 
 impl Decodable for RejectReason {
-    fn consensus_decode<R: io::Read + ?Sized>(r: &mut R) -> Result<Self, encode::Error> {
+    fn consensus_decode<R: Read + ?Sized>(r: &mut R) -> Result<Self, encode::Error> {
         Ok(match r.read_u8()? {
             0x01 => RejectReason::Malformed,
             0x10 => RejectReason::Invalid,

bitcoin/src/p2p/mod.rs

@@ -25,6 +25,7 @@ use core::{fmt, ops};
 
 use hex::FromHex;
 use internals::{debug_from_display, write_err};
+use io::{Read, Write};
 
 use crate::consensus::encode::{self, Decodable, Encodable};
 use crate::prelude::{Borrow, BorrowMut, String, ToOwned};
@@ -190,14 +191,14 @@ impl ops::BitXorAssign for ServiceFlags {
 
 impl Encodable for ServiceFlags {
     #[inline]
-    fn consensus_encode<W: io::Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
+    fn consensus_encode<W: Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
         self.0.consensus_encode(w)
     }
 }
 
 impl Decodable for ServiceFlags {
     #[inline]
-    fn consensus_decode<R: io::Read + ?Sized>(r: &mut R) -> Result<Self, encode::Error> {
+    fn consensus_decode<R: Read + ?Sized>(r: &mut R) -> Result<Self, encode::Error> {
         Ok(ServiceFlags(Decodable::consensus_decode(r)?))
     }
 }
@@ -283,13 +284,13 @@ impl fmt::UpperHex for Magic {
 }
 
 impl Encodable for Magic {
-    fn consensus_encode<W: io::Write + ?Sized>(&self, writer: &mut W) -> Result<usize, io::Error> {
+    fn consensus_encode<W: Write + ?Sized>(&self, writer: &mut W) -> Result<usize, io::Error> {
         self.0.consensus_encode(writer)
     }
 }
 
 impl Decodable for Magic {
-    fn consensus_decode<R: io::Read + ?Sized>(reader: &mut R) -> Result<Self, encode::Error> {
+    fn consensus_decode<R: Read + ?Sized>(reader: &mut R) -> Result<Self, encode::Error> {
         Ok(Magic(Decodable::consensus_decode(reader)?))
     }
 }

bitcoin/src/psbt/map/global.rs

@@ -70,7 +70,7 @@ impl Map for Psbt {
 }
 
 impl Psbt {
-    pub(crate) fn decode_global<R: io::Read + ?Sized>(r: &mut R) -> Result<Self, Error> {
+    pub(crate) fn decode_global<R: Read + ?Sized>(r: &mut R) -> Result<Self, Error> {
         let mut r = r.take(MAX_VEC_SIZE as u64);
         let mut tx: Option<Transaction> = None;
         let mut version: Option<u32> = None;

bitcoin/src/psbt/raw.rs

@@ -8,6 +8,8 @@
 
 use core::fmt;
 
+use io::{Read, Write};
+
 use super::serialize::{Deserialize, Serialize};
 use crate::consensus::encode::{
     self, deserialize, serialize, Decodable, Encodable, ReadExt, VarInt, WriteExt, MAX_VEC_SIZE,
@@ -72,7 +74,7 @@ impl fmt::Display for Key {
 }
 
 impl Key {
-    pub(crate) fn decode<R: io::Read + ?Sized>(r: &mut R) -> Result<Self, Error> {
+    pub(crate) fn decode<R: Read + ?Sized>(r: &mut R) -> Result<Self, Error> {
         let VarInt(byte_size): VarInt = Decodable::consensus_decode(r)?;
 
         if byte_size == 0 {
@@ -135,7 +137,7 @@ impl Deserialize for Pair {
 }
 
 impl Pair {
-    pub(crate) fn decode<R: io::Read + ?Sized>(r: &mut R) -> Result<Self, Error> {
+    pub(crate) fn decode<R: Read + ?Sized>(r: &mut R) -> Result<Self, Error> {
         Ok(Pair { key: Key::decode(r)?, value: Decodable::consensus_decode(r)? })
     }
 }
@@ -144,7 +146,7 @@ impl<Subtype> Encodable for ProprietaryKey<Subtype>
 where
     Subtype: Copy + From<u8> + Into<u8>,
 {
-    fn consensus_encode<W: io::Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
+    fn consensus_encode<W: Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
         let mut len = self.prefix.consensus_encode(w)? + 1;
         w.emit_u8(self.subtype.into())?;
         w.write_all(&self.key)?;
@@ -157,7 +159,7 @@ impl<Subtype> Decodable for ProprietaryKey<Subtype>
 where
     Subtype: Copy + From<u8> + Into<u8>,
 {
-    fn consensus_decode<R: io::Read + ?Sized>(r: &mut R) -> Result<Self, encode::Error> {
+    fn consensus_decode<R: Read + ?Sized>(r: &mut R) -> Result<Self, encode::Error> {
         let prefix = Vec::<u8>::consensus_decode(r)?;
         let subtype = Subtype::from(r.read_u8()?);
         let key = read_to_end(r)?;
@@ -194,7 +196,7 @@ where
 }
 
 // core2 doesn't have read_to_end
-pub(crate) fn read_to_end<D: io::Read + ?Sized>(d: &mut D) -> Result<Vec<u8>, io::Error> {
+pub(crate) fn read_to_end<D: Read + ?Sized>(d: &mut D) -> Result<Vec<u8>, io::Error> {
     let mut result = vec![];
     let mut buf = [0u8; 64];
     loop {

bitcoin/src/taproot/mod.rs

@@ -14,6 +14,7 @@ use core::iter::FusedIterator;
 
 use hashes::{sha256t_hash_newtype, Hash, HashEngine};
 use internals::write_err;
+use io::Write;
 use secp256k1::{self, Scalar, Secp256k1};
 
 use crate::consensus::Encodable;
@@ -1109,7 +1110,7 @@ impl ControlBlock {
     /// # Returns
     ///
     /// The number of bytes written to the writer.
-    pub fn encode<Write: io::Write + ?Sized>(&self, writer: &mut Write) -> io::Result<usize> {
+    pub fn encode<W: Write + ?Sized>(&self, writer: &mut W) -> io::Result<usize> {
         let first_byte: u8 =
             i32::from(self.output_key_parity) as u8 | self.leaf_version.to_consensus();
         writer.write_all(&[first_byte])?;

units/src/amount.rs

@@ -6,7 +6,7 @@
 //! We refer to the documentation on the types for more information.
 
 use core::cmp::Ordering;
-use core::fmt::{self, Write};
+use core::fmt::{self, Write as _};
 use core::str::FromStr;
 use core::{default, ops};