Merge rust-bitcoin/rust-bitcoin#3711: primitives: Reduce alloc requirements

6ae35be0db primitives: Reduce alloc requirements (Tobin C. Harding)

Pull request description:

  Recently we reduced the `alloc` requirements in `units` but we did not propagate these changes up to `primitives`.

  Remove a bunch of `alloc` feature gating from `primitives`.

ACKs for top commit:
  apoelstra:
    ACK 6ae35be0db84d2bf79ffe0cd63d616a55c036b12; successfully ran local tests; nice!

Tree-SHA512: a49076a72b81a68f7e0e03c452eb5490dcc69136b15834577ba10ec71767080cf74fd443e2668f008814ed677d4ee6b45972f6f52b78b8eb793e05780d10a2ec

primitives/src/lib.rs

@@ -31,7 +31,6 @@ extern crate std;
 extern crate serde;
 
 pub mod block;
-#[cfg(feature = "alloc")]
 pub mod locktime;
 pub mod merkle_tree;
 pub mod opcodes;
@@ -45,10 +44,8 @@ pub mod transaction;
 pub mod witness;
 
 #[doc(inline)]
-pub use units::amount::{self, Amount, SignedAmount};
-#[doc(inline)]
-#[cfg(feature = "alloc")]
 pub use units::{
+    amount::{self, Amount, SignedAmount},
     block::{BlockHeight, BlockInterval},
     fee_rate::{self, FeeRate},
     weight::{self, Weight},
@@ -60,13 +57,13 @@ pub use self::{
     block::{
         Block, Checked as BlockChecked, Unchecked as BlockUnchecked, Validation as BlockValidation,
     },
-    locktime::{absolute, relative},
     transaction::{Transaction, TxIn, TxOut},
     witness::Witness,
 };
 #[doc(inline)]
 pub use self::{
     block::{BlockHash, Header as BlockHeader, WitnessCommitment},
+    locktime::{absolute, relative},
     merkle_tree::{TxMerkleNode, WitnessMerkleNode},
     pow::CompactTarget,
     sequence::Sequence,

primitives/src/sequence.rs

@@ -20,12 +20,9 @@ use core::fmt;
 use arbitrary::{Arbitrary, Unstructured};
 #[cfg(feature = "serde")]
 use serde::{Deserialize, Serialize};
-#[cfg(feature = "alloc")]
 use units::locktime::relative::TimeOverflowError;
-#[cfg(feature = "alloc")]
 use units::parse::{self, PrefixedHexError, UnprefixedHexError};
 
-#[cfg(feature = "alloc")]
 use crate::locktime::relative;
 #[cfg(all(doc, feature = "alloc"))]
 use crate::transaction::Transaction;
@@ -127,14 +124,12 @@ impl Sequence {
     }
 
     /// Constructs a new `Sequence` from a prefixed hex string.
-    #[cfg(feature = "alloc")]
     pub fn from_hex(s: &str) -> Result<Self, PrefixedHexError> {
         let lock_time = parse::hex_u32_prefixed(s)?;
         Ok(Self::from_consensus(lock_time))
     }
 
     /// Constructs a new `Sequence` from an unprefixed hex string.
-    #[cfg(feature = "alloc")]
     pub fn from_unprefixed_hex(s: &str) -> Result<Self, UnprefixedHexError> {
         let lock_time = parse::hex_u32_unprefixed(s)?;
         Ok(Self::from_consensus(lock_time))
@@ -158,7 +153,6 @@ impl Sequence {
     ///
     /// Will return an error if the input cannot be encoded in 16 bits.
     #[inline]
-    #[cfg(feature = "alloc")]
     pub fn from_seconds_floor(seconds: u32) -> Result<Self, TimeOverflowError> {
         if let Ok(interval) = u16::try_from(seconds / 512) {
             Ok(Sequence::from_512_second_intervals(interval))
@@ -172,7 +166,6 @@ impl Sequence {
     ///
     /// Will return an error if the input cannot be encoded in 16 bits.
     #[inline]
-    #[cfg(feature = "alloc")]
     pub fn from_seconds_ceil(seconds: u32) -> Result<Self, TimeOverflowError> {
         if let Ok(interval) = u16::try_from((seconds + 511) / 512) {
             Ok(Sequence::from_512_second_intervals(interval))
@@ -191,7 +184,6 @@ impl Sequence {
 
     /// Constructs a new [`relative::LockTime`] from this [`Sequence`] number.
     #[inline]
-    #[cfg(feature = "alloc")]
     pub fn to_relative_lock_time(&self) -> Option<relative::LockTime> {
         use crate::locktime::relative::{Height, LockTime, Time};
 
@@ -211,7 +203,6 @@ impl Sequence {
     /// Returns the low 16 bits from sequence number.
     ///
     /// BIP-68 only uses the low 16 bits for relative lock value.
-    #[cfg(feature = "alloc")]
     fn low_u16(&self) -> u16 { self.0 as u16 }
 }