Issue #19377 has been updated by Eregon (Benoit Daloze). Currently `Fiber#storage` can only be called for the current Fiber (otherwise `ArgumentError`). But it may evolve (e.g. allow to be called on different Fiber but Fiber of same thread), this is why it's Fiber#storage and not Fiber.storage. Additionally, `Fiber#storage` and `Fiber#storage=` are expected to be much rarer to use. IMHO it would feel weird to have them as class methods on `Fiber`. For instance `Fiber#storage` shouldn't be used by regular users, only for debugging or for copying storage from one Fiber to another (e.g. useful for thread pools). ---------------------------------------- Feature #19377: Rename Fiber#storage to Fiber.storage https://bugs.ruby-lang.org/issues/19377#change-101953 * Author: zverok (Victor Shepelev) * Status: Open * Priority: Normal ---------------------------------------- Justification: * `#storage`, which pretends to be an instance method, is always available only on `Fiber.current`, which is [problematic to document](https://github.com/ruby/ruby/pull/6985#discussion_r1055796069), and needs special handling when `storage` is called for non-current Fiber; * with class method + docs "storage of the current fiber" it all will be self-evident; * Most of the time, when we declare methods that are available only in the current {something}, they are class methods. (like storage's itself interface of `Fiber::[]` and `Fiber::[]=`, or `Module.used_modules`, which is modules and refinements of the _current context_, but it is not `self.used_modules`, for example) * Code like ```ruby Fiber.current.storage = {foo: 'bar'} Fiber[:foo] ``` ...looks like it is two unrelated things (storage of the _current_ fiber vs some "global" key getter/setter?) I don't see much discussion of this in #19078. Matz in #19078#note-22, while accepting the interface, describes it as homogenous:
(1) fiber[key]/fiber[key]=val - accepted. (2) fiber.storage => hash - accepted (3) fiber.storage=hash - should be experimental ...
So I believe it should be either `Fiber.current[]` and `Fiber.current.storage`, or `Fiber[]`, and `Fiber.storage`. The latter is preferable to underline it is only one, related to the current fiber, interface, not "every fiber instance has one (but actually you can use only `current`'s) -- https://bugs.ruby-lang.org/