Added a ?Sized constraint to T in Mutex<T>

CHANGELOG.md

@@ -7,7 +7,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
-No unreleased changes yet
+- Added a `?Sized` constraint to `T` in `Mutex<T>`, allowing it to work with unsized types, such as trait objects.
 
 ## [v1.1.2] - 2023-08-09
 
@@ -69,20 +69,21 @@ If you're seeing a linker error like `undefined symbol: _critical_section_1_0_ac
   ```
 
 - For single-core Cortex-M targets in privileged mode:
+
   ```toml
   [dependencies]
   cortex-m = { version = "0.7.6", features = ["critical-section-single-core"]}
   ```
 
 - For single-hart RISC-V targets in privileged mode:
+
   ```toml
   [dependencies]
   riscv = { version = "0.10", features = ["critical-section-single-hart"]}
   ```
 
 - For other targets: check if your HAL or architecture-support crate has a `critical-section 1.0` implementation available. Otherwise, [provide your own](https://github.com/rust-embedded/critical-section#providing-an-implementation).
 
-
 ## [v0.2.7] - 2022-04-08
 
 - Add support for AVR targets.

src/mutex.rs

@@ -71,7 +71,7 @@ use core::cell::{Ref, RefCell, RefMut, UnsafeCell};
 /// [`std::sync::Mutex`]: https://doc.rust-lang.org/std/sync/struct.Mutex.html
 /// [interior mutability]: https://doc.rust-lang.org/reference/interior-mutability.html
 #[derive(Debug)]
-pub struct Mutex<T> {
+pub struct Mutex<T: ?Sized> {
     inner: UnsafeCell<T>,
 }