From 9b7060ad3123eb21e7d93b59e2a21482afe36b6c Mon Sep 17 00:00:00 2001
From: Mara Bos <m-ou.se@m-ou.se>
Date: Fri, 21 Mar 2025 16:51:14 +0100
Subject: [PATCH] Add todo comment on using a niche type for fmt flags.

---
 library/core/src/fmt/mod.rs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/library/core/src/fmt/mod.rs b/library/core/src/fmt/mod.rs
index e4642470008..54c84b07d06 100644
--- a/library/core/src/fmt/mod.rs
+++ b/library/core/src/fmt/mod.rs
@@ -299,6 +299,8 @@ pub struct FormattingOptions {
     ///      a &str size when stored in (the upper bits of) the same field.
     ///      (fmt::Arguments will make use of this property in the future.)
     /// ```
+    // Note: This could use a special niche type with range 0x8000_0000..=0xfdd0ffff.
+    // It's unclear if that's useful, though.
     flags: u32,
     /// Width if width flag (bit 27) above is set. Otherwise, always 0.
     width: u16,