diff --git a/src/libcore/sync/atomic.rs b/src/libcore/sync/atomic.rs index d336934ec7214..62e0979c5fefc 100644 --- a/src/libcore/sync/atomic.rs +++ b/src/libcore/sync/atomic.rs @@ -1425,8 +1425,8 @@ assert_eq!(foo.load(Ordering::SeqCst), 0b011110); doc_comment! { concat!("Fetches the value, and applies a function to it that returns an optional -new value. Returns a `Result` (`Ok(_)` if the function returned `Some(_)`, else `Err(_)`) of the -previous value. +new value. Returns a `Result` of `Ok(previous_value)` if the function returned `Some(_)`, else +`Err(previous_value)`. Note: This may call the function multiple times if the value has been changed from other threads in the meantime, as long as the function returns `Some(_)`, but the function will have been applied