# Thread Local Storage

[thread_local_storage]

oneAPI Threading Building Blocks provides class templates for thread local storage (TLS). Each provides a thread-local element per thread and lazily creates elements on demand.

- combinable
- enumerable_thread_specific

This section also describes class template `flatten2d`, which assists a common idiom where an `enumerable_thread_specific` represents a container partitioner across threads.

- flattened2d