From 995e932711b43da7ba445e609feaacf68572d5fd Mon Sep 17 00:00:00 2001
From: Chris Krycho <hello@chriskrycho.com>
Date: Wed, 10 Jul 2024 18:14:59 -0600
Subject: [PATCH] Use Rust 2021 Edition for mdBook

A number of examples *already* do not work correctly, and the inbound
async chapter requires Rust 2021.
---
 book.toml | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/book.toml b/book.toml
index b73ff03b7a..800adcf0f5 100644
--- a/book.toml
+++ b/book.toml
@@ -15,3 +15,6 @@ git-repository-url = "https://github.com/rust-lang/book"
 
 [preprocessor.trpl-listing]
 output-mode = "default"
+
+[rust]
+edition = "2021"