Why thread locks are templated

Question

Hi.

We have unique_lock, Lock guard and just wondering why they are templated class ?

We generally have mutex as template parameters. What else could be used with these locks ?

Answer 1

Because they are templated,std::unique_lock and std::lock_guard can function with a variety of synchronization primitives. They can operate with additional kinds of mutex-like objects in addition to standard::mutex by creating them as templates.

Typical types for template parameters include: mutex
the typical mutex type used for simple locking.

Recursive_mutex std::
permits numerous acquisitions of the mutex by the same thread.

Std::timed_mutex
provides more timed locking functionality.

Recursive_timed_mutex std::
a recursive and timed mutex combo.

Implementations of custom mutexes
Using unique_lock or lock_guard, you can create your own mutex class that complies with the Lockable or TimedLockable principles.

The templated design allows:
1. Generic locking mechanisms
2. Extensibility
3. Code Reusability

Answer 2

Thanks Sanjai.
Just curious to know why someone would choose to have custom mutex? Is mutex not enough in some scenarios (For Example)?