concatEager.swift

import RxSwift

extension ObservableType {
  public static func concatEager<S: Sequence>(_ sequence: S) -> Observable<Self.Element>
    where S.Element == Observable<Self.Element> {
    let multicastedObservables = sequence.map {
      $0.multicast(ReplaySubject.createUnbounded())
    }
    var disposables: [Disposable] = []
    
    return Self
      .deferred {
        disposables = multicastedObservables.map({ $0.connect() })
        return Self.concat(multicastedObservables)
      }
      .do(onDispose: { disposables.forEach({ $0.dispose() }) })
  }

  public static func concatEager<C: Collection>(_ collection: C) -> Observable<Self.Element>
    where C.Element == Observable<Self.Element> {
    let multicastedObservables = collection.map {
      $0.multicast(ReplaySubject.createUnbounded())
    }
    var disposables: [Disposable] = []
    
    return Self
      .deferred {
        disposables = multicastedObservables.map({ $0.connect() })
        return Self.concat(multicastedObservables)
      }
      .do(onDispose: { disposables.forEach({ $0.dispose() }) })
  }

  public static func concatEager(_ sources: Observable<Self.Element>...) -> Observable<Self.Element> {
    let multicastedObservables = sources.map {
      $0.multicast(ReplaySubject.createUnbounded())
    }
    var disposables: [Disposable] = []
    
    return Self
      .deferred {
        disposables = multicastedObservables.map({ $0.connect() })
        return Self.concat(multicastedObservables)
      }
      .do(onDispose: { disposables.forEach({ $0.dispose() }) })
  }
}