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| author | Julian Knodt <julianknodt@gmail.com> | 2025-05-13 11:17:09 +0900 |
|---|---|---|
| committer | Julian Knodt <julianknodt@gmail.com> | 2025-05-13 12:34:53 +0900 |
| commit | ab1c49a7facad5083c20407a2b1fd0b2104e174e (patch) | |
| tree | a1a87ad5180e6c482faad0e9f7a0ac7348e65e7a | |
| parent | 8405332bdf09b153e475f83b8b8ebf8d4e8eb81f (diff) | |
| download | rust-ab1c49a7facad5083c20407a2b1fd0b2104e174e.tar.gz rust-ab1c49a7facad5083c20407a2b1fd0b2104e174e.zip | |
Add `#[must_use]` to Array::map
The output of Array::map is intended to be an array of the same size, and does not modify the original in place nor is it intended for side-effects. Thus, under normal circumstances it should be consumed. See [discussion](https://internals.rust-lang.org/t/array-map-annotate-with-must-use/22813/26). Attaching to tracking issue #75243
| -rw-r--r-- | library/core/src/array/mod.rs | 1 | ||||
| -rw-r--r-- | library/coretests/tests/array.rs | 2 |
2 files changed, 2 insertions, 1 deletions
diff --git a/library/core/src/array/mod.rs b/library/core/src/array/mod.rs index efa7bed7c8e..4476e3f7923 100644 --- a/library/core/src/array/mod.rs +++ b/library/core/src/array/mod.rs @@ -531,6 +531,7 @@ impl<T, const N: usize> [T; N] { /// let y = x.map(|v| v.len()); /// assert_eq!(y, [6, 9, 3, 3]); /// ``` + #[must_use] #[stable(feature = "array_map", since = "1.55.0")] pub fn map<F, U>(self, f: F) -> [U; N] where diff --git a/library/coretests/tests/array.rs b/library/coretests/tests/array.rs index b6d18f1ec38..30ccbbc3203 100644 --- a/library/coretests/tests/array.rs +++ b/library/coretests/tests/array.rs @@ -325,7 +325,7 @@ fn array_map_drop_safety() { let success = std::panic::catch_unwind(|| { let items = [0; 10]; let mut nth = 0; - items.map(|_| { + let _ = items.map(|_| { assert!(nth < num_to_create); nth += 1; DropCounter |