queue: Update for 2nd edition.

jimblandy · jimblandy · commit dc2350d9dad4 · 2021-06-13T17:03:55.000-07:00
diff --git a/queue/Cargo.toml b/queue/Cargo.toml
@@ -2,5 +2,6 @@
 name = "queue"
 version = "0.1.0"
 authors = ["You <you@example.com>"]
+edition = "2018"
 
 [dependencies]
diff --git a/queue/src/lib.rs b/queue/src/lib.rs
@@ -1,4 +1,7 @@
-/// A last-in, first-out queue of characters.
+#![warn(rust_2018_idioms)]
+#![allow(elided_lifetimes_in_paths)]
+
+/// A first-in, first-out queue of characters.
 pub struct Queue {
     older: Vec<char>,   // older elements, eldest last.
     younger: Vec<char>  // younger elements, youngest last.
