  /**
   * Merges the specified observable sequences into one observable sequence by using the selector function whenever any of the observable sequences or Promises produces an element.
   *
   * @example
   * 1 - obs = Rx.Observable.combineLatest(obs1, obs2, obs3, function (o1, o2, o3) { return o1 + o2 + o3; });
   * 2 - obs = Rx.Observable.combineLatest([obs1, obs2, obs3], function (o1, o2, o3) { return o1 + o2 + o3; });
   * @returns {Observable} An observable sequence containing the result of combining elements of the sources using the specified result selector function.
   */
  var combineLatest = Observable.combineLatest = function () {
    var args = slice.call(arguments), resultSelector = args.pop();

    if (Array.isArray(args[0])) {
      args = args[0];
    }

    return new AnonymousObservable(function (observer) {
      var falseFactory = function () { return false; },
        n = args.length,
        hasValue = arrayInitialize(n, falseFactory),
        hasValueAll = false,
        isDone = arrayInitialize(n, falseFactory),
        values = new Array(n);

      function next(i) {
        var res;
        hasValue[i] = true;
        if (hasValueAll || (hasValueAll = hasValue.every(identity))) {
          try {
            res = resultSelector.apply(null, values);
          } catch (ex) {
            observer.onError(ex);
            return;
          }
          observer.onNext(res);
        } else if (isDone.filter(function (x, j) { return j !== i; }).every(identity)) {
          observer.onCompleted();
        }
      }

      function done (i) {
        isDone[i] = true;
        if (isDone.every(identity)) {
          observer.onCompleted();
        }
      }

      var subscriptions = new Array(n);
      for (var idx = 0; idx < n; idx++) {
        (function (i) {
          var source = args[i], sad = new SingleAssignmentDisposable();
          isPromise(source) && (source = observableFromPromise(source));
          sad.setDisposable(source.subscribe(function (x) {
              values[i] = x;
              next(i);
            },
            function(e) { observer.onError(e); },
            function () { done(i); }
          ));
          subscriptions[i] = sad;
        }(idx));
      }

      return new CompositeDisposable(subscriptions);
    }, this);
  };
