//! `parking_lot::Mutex` backend (default, enabled by the `parking-lot`
//! Cargo feature).
/// Lock used by the containers. Behaves like a mutex on `()`.
pub type SyncLock = Mutex;
/// Guard returned by [`SyncLock::lock`]. Only ever held, never dereferenced.
pub type SyncLockGuard<'a> = MutexGuard;