From 03b60dd5619bb65dff697cf9dd96f57ccc23f35e Mon Sep 17 00:00:00 2001
From: Anthony Grondin <104731965+AnthonyGrondin@users.noreply.github.com>
Date: Wed, 30 Jul 2025 16:01:11 -0400
Subject: feat(embassy-sync): Add `get_mut` for `LazyLock`

---
 embassy-sync/CHANGELOG.md     |  2 ++
 embassy-sync/src/lazy_lock.rs | 15 +++++++++++++++
 2 files changed, 17 insertions(+)

(limited to 'embassy-sync')

diff --git a/embassy-sync/CHANGELOG.md b/embassy-sync/CHANGELOG.md
index 89684de0c..c445e9ba1 100644
--- a/embassy-sync/CHANGELOG.md
+++ b/embassy-sync/CHANGELOG.md
@@ -7,6 +7,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## Unreleased
 
+- Add `get_mut` to `LazyLock`
+
 ## 0.7.0 - 2025-05-28
 
 - Add `remove_if` to `priority_channel::{Receiver, PriorityChannel}`.
diff --git a/embassy-sync/src/lazy_lock.rs b/embassy-sync/src/lazy_lock.rs
index f1bd88b61..a919f0037 100644
--- a/embassy-sync/src/lazy_lock.rs
+++ b/embassy-sync/src/lazy_lock.rs
@@ -57,6 +57,14 @@ impl<T, F: FnOnce() -> T> LazyLock<T, F> {
         unsafe { &(*self.data.get()).value }
     }
 
+    /// Get a mutable reference to the underlying value, initializing it if it
+    /// has not been done already.
+    #[inline]
+    pub fn get_mut(&mut self) -> &mut T {
+        self.ensure_init_fast();
+        unsafe { &mut (*self.data.get()).value }
+    }
+
     /// Consume the `LazyLock`, returning the underlying value. The
     /// initialization function will be called if it has not been
     /// already.
@@ -122,6 +130,13 @@ mod tests {
         assert_eq!(reference, &20);
     }
     #[test]
+    fn test_lazy_lock_mutation() {
+        let mut value: LazyLock<u32> = LazyLock::new(|| 20);
+        *value.get_mut() = 21;
+        let reference = value.get();
+        assert_eq!(reference, &21);
+    }
+    #[test]
     fn test_lazy_lock_into_inner() {
         let lazy: LazyLock<u32> = LazyLock::new(|| 20);
         let value = lazy.into_inner();
-- 
cgit