Adds deprecation explanation for Variable. ReactiveX#1501

kzaher · kzaher · commit e1933ebe219e · 2017-11-26T19:03:10.000+01:00
diff --git a/RxSwift/Deprecated.swift b/RxSwift/Deprecated.swift
@@ -156,6 +156,17 @@ extension ObservableType {
 ///
 /// Unlike `BehaviorSubject` it can't terminate with error, and when variable is deallocated
 /// it will complete its observable sequence (`asObservable`).
+///
+/// **This concept will be deprecated from RxSwift but offical migration path hasn't been decided yet.**
+/// https://github.com/ReactiveX/RxSwift/issues/1501
+///
+/// Current recommended replacement for this API is `RxCocoa.BehaviorRelay` because:
+/// * `Variable` isn't a standard cross platform concept, hence it's out of place in RxSwift target.
+/// * It doesn't have a counterpart for handling events (`PublishRelay`). It models state only.
+/// * It doesn't have a consistent naming with *Relay or other Rx concepts.
+/// * It has an inconsistent memory management model compared to other parts of RxSwift (completes on `deinit`).
+///
+/// Once plans are finalized, official availability attribute will be added in one of upcoming versions.
 public final class Variable<Element> {
 
     public typealias E = Element
