add some basic parsing and formatting benches

.github/workflows/rust.yml

@@ -54,6 +54,22 @@ jobs:
     - name: Smoke test
       run: cargo run --manifest-path tests/smoke-test/Cargo.toml
 
+  benches:
+    name: Benches
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout sources
+        uses: actions/checkout@v2
+
+      - name: Install Rust toolchain
+        run: rustup default nightly
+
+      - name: Default features
+        uses: actions-rs/cargo@v1
+        with:
+          command: bench
+          args: --no-run
+
   embedded:
     name: Build (embedded)
     runs-on: ubuntu-latest

benches/parse.rs

@@ -0,0 +1,96 @@
+#![feature(test)]
+
+extern crate test;
+
+use std::{
+    fmt::{self, Display},
+    str::FromStr,
+};
+
+bitflags::bitflags! {
+    struct Flags10: u32 {
+        const A = 0b0000_0000_0000_0001;
+        const B = 0b0000_0000_0000_0010;
+        const C = 0b0000_0000_0000_0100;
+        const D = 0b0000_0000_0000_1000;
+        const E = 0b0000_0000_0001_0000;
+        const F = 0b0000_0000_0010_0000;
+        const G = 0b0000_0000_0100_0000;
+        const H = 0b0000_0000_1000_0000;
+        const I = 0b0000_0001_0000_0000;
+        const J = 0b0000_0010_0000_0000;
+    }
+}
+
+impl FromStr for Flags10 {
+    type Err = bitflags::parser::ParseError;
+
+    fn from_str(flags: &str) -> Result<Self, Self::Err> {
+        Ok(Flags10(flags.parse()?))
+    }
+}
+
+impl Display for Flags10 {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        Display::fmt(&self.0, f)
+    }
+}
+
+#[bench]
+fn format_flags_1_present(b: &mut test::Bencher) {
+    b.iter(|| Flags10::J.to_string())
+}
+
+#[bench]
+fn format_flags_5_present(b: &mut test::Bencher) {
+    b.iter(|| (Flags10::F | Flags10::G | Flags10::H | Flags10::I | Flags10::J).to_string())
+}
+
+#[bench]
+fn format_flags_10_present(b: &mut test::Bencher) {
+    b.iter(|| {
+        (Flags10::A
+            | Flags10::B
+            | Flags10::C
+            | Flags10::D
+            | Flags10::E
+            | Flags10::F
+            | Flags10::G
+            | Flags10::H
+            | Flags10::I
+            | Flags10::J)
+            .to_string()
+    })
+}
+
+#[bench]
+fn parse_flags_1_10(b: &mut test::Bencher) {
+    b.iter(|| {
+        let flags: Flags10 = "J".parse().unwrap();
+        flags
+    })
+}
+
+#[bench]
+fn parse_flags_5_10(b: &mut test::Bencher) {
+    b.iter(|| {
+        let flags: Flags10 = "F | G | H | I | J".parse().unwrap();
+        flags
+    })
+}
+
+#[bench]
+fn parse_flags_10_10(b: &mut test::Bencher) {
+    b.iter(|| {
+        let flags: Flags10 = "A | B | C | D | E | F | G | H | I | J".parse().unwrap();
+        flags
+    })
+}
+
+#[bench]
+fn parse_flags_1_10_hex(b: &mut test::Bencher) {
+    b.iter(|| {
+        let flags: Flags10 = "0xFF".parse().unwrap();
+        flags
+    })
+}