Add must_use to StrExt methods

rust-analyzer · Feb 8, 2024 · 0078fdf · 0078fdf
1 parent fe7064e
commit 0078fdf
Showing 1 changed file with 4 additions and 0 deletions.
diff --git a/src/lib.rs b/src/lib.rs
@@ -551,24 +551,28 @@ pub trait StrExt: private::Sealed {
     /// potentially without allocating.
     ///
     /// See [`str::to_lowercase`].
+    #[must_use = "this returns a new SmolStr without modifying the original"]
     fn to_lowercase_smolstr(&self) -> SmolStr;
 
     /// Returns the uppercase equivalent of this string slice as a new [`SmolStr`],
     /// potentially without allocating.
     ///
     /// See [`str::to_uppercase`].
+    #[must_use = "this returns a new SmolStr without modifying the original"]
     fn to_uppercase_smolstr(&self) -> SmolStr;
 
     /// Returns the ASCII lowercase equivalent of this string slice as a new [`SmolStr`],
     /// potentially without allocating.
     ///
     /// See [`str::to_ascii_lowercase`].
+    #[must_use = "this returns a new SmolStr without modifying the original"]
     fn to_ascii_lowercase_smolstr(&self) -> SmolStr;
 
     /// Returns the ASCII uppercase equivalent of this string slice as a new [`SmolStr`],
     /// potentially without allocating.
     ///
     /// See [`str::to_ascii_uppercase`].
+    #[must_use = "this returns a new SmolStr without modifying the original"]
     fn to_ascii_uppercase_smolstr(&self) -> SmolStr;
 }