use aoc crate for common stuff

aoc/Cargo.toml

@@ -0,0 +1,9 @@
+[package]
+name = "aoc"
+version = "0.1.0"
+authors = ["Antoine Martin <antoine97.martin@gmail.com>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]

aoc/src/lib.rs

@@ -0,0 +1,6 @@
+pub type Result<T> = std::result::Result<T, Box<dyn std::error::Error>>;
+
+#[macro_export]
+macro_rules! err {
+    ($($string:expr),+) => (Box::<dyn std::error::Error>::from(format!($($string),+)))
+}