Fix clippy issues

src/lib.rs

@@ -105,7 +105,7 @@ thread_local! {
     ///
     /// Assuming that locks are roughly released in the reverse order in which they were acquired,
     /// a stack should be more efficient to keep track of the current state than a set would be.
-    static HELD_LOCKS: RefCell<Vec<usize>> = RefCell::new(Vec::new());
+    static HELD_LOCKS: RefCell<Vec<usize>> = const { RefCell::new(Vec::new()) };
 }
 
 /// Dedicated ID type for Mutexes
@@ -275,7 +275,7 @@ struct BorrowedMutex<'a> {
 ///
 /// This function panics if the lock did not appear to be handled by this thread. If that happens,
 /// that is an indication of a serious design flaw in this library.
-impl<'a> Drop for BorrowedMutex<'a> {
+impl Drop for BorrowedMutex<'_> {
     fn drop(&mut self) {
         // Safety: the only way to get a BorrowedMutex is by locking the mutex.
         unsafe { self.id.mark_released() };

src/stdsync.rs

@@ -161,21 +161,21 @@ pub mod tracing {
         }
     }
 
-    impl<'a, T> Deref for MutexGuard<'a, T> {
+    impl<T> Deref for MutexGuard<'_, T> {
         type Target = T;
 
         fn deref(&self) -> &Self::Target {
             &self.inner
         }
     }
 
-    impl<'a, T> DerefMut for MutexGuard<'a, T> {
+    impl<T> DerefMut for MutexGuard<'_, T> {
         fn deref_mut(&mut self) -> &mut Self::Target {
             &mut self.inner
         }
     }
 
-    impl<'a, T: fmt::Display> fmt::Display for MutexGuard<'a, T> {
+    impl<T: fmt::Display> fmt::Display for MutexGuard<'_, T> {
         fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
             self.inner.fmt(f)
         }
@@ -409,7 +409,7 @@ pub mod tracing {
         }
     }
 
-    impl<'a, L, T> Deref for TracingRwLockGuard<'a, L>
+    impl<L, T> Deref for TracingRwLockGuard<'_, L>
     where
         L: Deref<Target = T>,
     {
@@ -420,7 +420,7 @@ pub mod tracing {
         }
     }
 
-    impl<'a, T, L> DerefMut for TracingRwLockGuard<'a, L>
+    impl<T, L> DerefMut for TracingRwLockGuard<'_, L>
     where
         L: Deref<Target = T> + DerefMut,
     {
@@ -439,6 +439,8 @@ pub mod tracing {
         mutex_id: LazyMutexId,
     }
 
+    // New without default is intentional, `std::sync::Once` doesn't implement it either
+    #[allow(clippy::new_without_default)]
     impl Once {
         /// Create a new `Once` value.
         pub const fn new() -> Self {