Module id_generator 

Ids handed out under a lock, to tell one thing apart from another that replaced it.

Two shapes use this, and the difference lives in the caller, not in the id:

• a generation, compared against IdGenerator::latest to tell whether something built with the lock released is still the current one — see SharedDisposal and Switch;
• a key, identifying an entry of a collection — see MergeAll and PublishSubject.

An Id can only come from an IdGenerator, which never hands the same one out twice, so a holder of an id cannot forge one that collides with a later value.

Structs

Id

An id handed out by an IdGenerator.

IdGenerator

Hands out an Id that is never equal to any it handed out before.