diff options
Diffstat (limited to 'library/core/src/option.rs')
| -rw-r--r-- | library/core/src/option.rs | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/library/core/src/option.rs b/library/core/src/option.rs index 9b6ff76b240..1020e655579 100644 --- a/library/core/src/option.rs +++ b/library/core/src/option.rs @@ -1125,6 +1125,7 @@ impl<T> Option<T> { /// ``` #[inline] #[stable(feature = "rust1", since = "1.0.0")] + #[must_use = "if you don't need the returned value, use `if let` instead"] pub fn map_or<U, F>(self, default: U, f: F) -> U where F: FnOnce(T) -> U, |