Prepare the bitvec! fix for publication

CHANGELOG.md

@@ -4,6 +4,14 @@ All notable changes will be documented in this file.
 
 This document is written according to the [Keep a Changelog][kac] style.
 
+## 0.15.2
+
+### Changed
+
+The `bitvec![bit; rep]` construction macro has its implementation rewritten to
+be much faster. This fault was reported by GitHub user [@caelunshun] in
+[Issue #28].
+
 ## 0.15.1
 
 ### Removed
@@ -465,6 +473,7 @@ Initial implementation and release.
 - `bitvec!` generator macro
 
 [@GeorgeGkas]: https://github.com/GeorgeGkas
+[@caelunshun]: https://github.com/caelunshun
 [@geq1t]: https://github.com/geq1t
 [@koushiro]: https://github.com/koushiro
 [@overminder]: https://github.com/overminder
@@ -478,5 +487,6 @@ Initial implementation and release.
 [Issue #12]: https://github.com/myrrlyn/bitvec/issues/12
 [Issue #15]: https://github.com/myrrlyn/bitvec/issues/15
 [Issue #16]: https://github.com/myrrlyn/bitvec/issues/16
+[Issue #28]: https://github.com/myrrlyn/bitvec/issues/28
 [`Sync`]: https://doc.rust-lang.org/stable/core/marker/trait.Sync.html
 [kac]: https://keepachangelog.com/en/1.0.0/

Cargo.toml

@@ -6,7 +6,7 @@
 
 [package]
 name = "bitvec"
-version = "0.15.1"
+version = "0.15.2"
 authors = [
 	"myrrlyn <[email protected]>",
 ]

benches/macros.rs

@@ -0,0 +1,31 @@
+/*! Macro construction benchmarks.
+
+This is taken from [issue #28], which noted that the `bitvec![bit; rep]`
+expansion was horribly inefficient.
+
+This benchmark crate should be used for all macro performance recording, and
+compare the macros against `vec!`. While `vec!` will always be faster, because
+`bitvec!` does more work than `vec!`, they should at least be close.
+
+Original performance was 10,000x slower. Performance after the fix for #28 was
+within 20ns.
+
+[issue #28]: https://github.com/myrrlyn/bitvec/issues/28
+!*/
+
+#![feature(test)]
+
+extern crate test;
+
+use test::Bencher;
+use bitvec::prelude::*;
+
+#[bench]
+fn bitvec_init(b: &mut Bencher) {
+	b.iter(|| bitvec![0; 16 * 16 * 9]);
+}
+
+#[bench]
+fn vec_init(b: &mut Bencher) {
+	b.iter(|| vec![0u8; 16 * 16 * 9 / 8]);
+}