Rentable Cache

[TonyValenti]

I am looking for a class that functions like follows:

1. I "rent" an instance of an item using a key.
2. If no instance with that key exists, one is created and returned. Otherwise, the existing one is returned.
3. When I am done with my instance, I release it.
4. When an item has no active renters, it is purged from the cache.

Does a class like this already exist? If so, what is it called?

[davidfowl]

https://learn.microsoft.com/en-us/dotnet/api/microsoft.extensions.caching.memory.memorycache?view=dotnet-plat-ext-7.0