From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Sun, 4 Feb 2024 12:53:20 +0000 (+0000)
Subject: Reduce String consing in reply userid
X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ian/git?a=commitdiff_plain;h=62e352afb149bc3f6e57637c46eabb019b8f7405;p=mastodonochrome.git

Reduce String consing in reply userid

Not sure if this is worthwile.  You may want to suppress the lint
clippy::format_collect instead.
---

diff --git a/src/posting.rs b/src/posting.rs
index 82ba71b..f6062e3 100644
--- a/src/posting.rs
+++ b/src/posting.rs
@@ -1,3 +1,4 @@
+use std::fmt::Write as _;
 use std::iter::once;
 use sys_locale::get_locale;
 
@@ -103,7 +104,10 @@ impl Post {
             .chain(st.mentions.iter().map(|m| client.fq(&m.acct)))
             .filter(|acct| acct != &ourself);
 
-        let text = userids.map(|acct| format!("@{} ", acct)).collect();
+        let text = userids.fold(String::new(), |mut s, acct| {
+            write!(s, "@{} ", acct).expect("fmt to string failed");
+            s
+        });
 
         // Set a default content warning of the same as the post we're
         // replying to.