Use a common macro to instrument each part

Cargo.lock

@@ -8,9 +8,14 @@ version = "1.0.51"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8b26702f315f53b6071259e15dd9d64528213b44d61de1ec926eca7715d62203"
 
+[[package]]
+name = "common"
+version = "0.1.0"
+
 [[package]]
 name = "day01"
 version = "0.1.0"
 dependencies = [
  "anyhow",
+ "common",
 ]

crates/common/Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "common"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]

crates/common/src/lib.rs

@@ -0,0 +1,14 @@
+use std::time::Instant;
+
+#[macro_export]
+macro_rules! instrument {
+    ($part1:expr, $part2:expr) => {
+        let mut now = Instant::now();
+        println!("Part 1: {}", $part1);
+        println!("(elapsed: {:?})", now.elapsed());
+        now = Instant::now();
+        println!("");
+        println!("Part 2: {}", $part2);
+        println!("(elapsed: {:?})", now.elapsed());
+    };
+}

crates/day01/Cargo.toml

@@ -7,3 +7,4 @@ edition = "2021"
 
 [dependencies]
 anyhow = "1.0"
+common = { path = "../common" }

crates/day01/src/main.rs

@@ -1,6 +1,6 @@
-use std::time::Instant;
-
 use anyhow::Result;
+use common::instrument;
+use std::time::Instant;
 
 const INPUT: &str = include_str!("input/input.txt");
 
@@ -41,13 +41,7 @@ fn solve_part2(input: &str) -> Result<i32> {
 }
 
 fn main() {
-    let mut now = Instant::now();
-    println!("Part 1: {}", solve_part1(INPUT).unwrap());
-    println!("(elapsed: {:?})", now.elapsed());
-    now = Instant::now();
-    println!("");
-    println!("Part 2: {}", solve_part2(INPUT).unwrap());
-    println!("(elapsed: {:?})", now.elapsed());
+    instrument!(solve_part1(INPUT).unwrap(), solve_part2(INPUT).unwrap());
 }
 
 #[cfg(test)]