[ObservableType+] Adds additional sugar to `ObservableType`

ObservableType+.swift

import Foundation
import RxSwift
import RxCocoa

extension ObservableType {
    /// Unwraps an Optional Element if it's present
    ///
    /// - Returns: The safely unwrapped item
    func unwrap<T>() -> Observable<T> where E == Optional<T> {
        return filter { $0 != nil }.map { $0! }
    }

    /// Merges the current Observable with another Observer
    ///
    /// - Parameter other: Observable that should be merged in
    /// - Returns: An observable that emits events from both Observables
    func merge(with other: Observable<E>) -> Observable<E> {
        return Observable.merge(self.asObservable(), other)
    }
}


extension ObservableType where E == Bool {
    /// Boolean not operator
    public func not() -> Observable<Bool> {
        return self.map(!)
    }
}