Mark SettingsBindDropGuard as must_use

Author: mitsuhiko

CHANGELOG.md

@@ -4,8 +4,9 @@ All notable changes to insta and cargo-insta are documented here.
 
 ## 1.30.0
 
--  Write inline snapshots with atomic rename to avoid some rare races.  (#373)
--  Pass `--color=...` to libtest to propagate color choices in more situations.  (#375)
+- Mark settings drop guard as `#[must_use]`.
+- Write inline snapshots with atomic rename to avoid some rare races.  (#373)
+- Pass `--color=...` to libtest to propagate color choices in more situations.  (#375)
 
 ## 1.29.0
 

src/settings.rs

@@ -580,6 +580,7 @@ impl Settings {
 }
 
 /// Returned from [`bind_to_scope`](Settings::bind_to_scope)
+#[must_use = "The guard is immediately dropped so binding has no effect. Use `let _guard = ...` to bind it."]
 pub struct SettingsBindDropGuard(Option<Arc<ActualSettings>>);
 
 impl Drop for SettingsBindDropGuard {