# parking_lot::MappedFairMutexGuard - Rust
An RAII mutex guard returned by `FairMutexGuard::map`, which can point to a subfield of the protected data.
Keywords: rust, rustlang, rust-lang, MappedFairMutexGuard

# Type Definition parking_lot::MappedFairMutexGuard [−] [src]

    type MappedFairMutexGuard<'a, T> = MappedMutexGuard<'a, RawFairMutex, T>;

An RAII mutex guard returned by `FairMutexGuard::map`, which can point to a subfield of the protected data.

The main difference between `MappedFairMutexGuard` and `FairMutexGuard` is that the former doesn’t support temporarily unlocking and re-locking, since that could introduce soundness issues if the locked object is modified by another thread.