What is the difference between unique_lock and shared-lock?

[JUAN DENT]

As far as I can tell, only one unique_lock can be associated with a mutex, while several shared_locks can be associated with a common mutex. Why is this useful? Can someone provide an example?

When to use one or the other?

Regards,
Juan Dent

[keskiverto]

Apparently to allow simultaneous (shared) read access.
Writers must use exclusive access.

https://stackoverflow.com/questions/46049803/difference-between-shared-mutex-and-mutex-why-do-both-exist-in-c-11
https://en.cppreference.com/w/cpp/thread/shared_mutex