/**
 * Copyright 2014 Netflix, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package rx.internal.operators;

import rx.Observable.Operator;
import rx.Subscriber;

/**
 * Hides the identity of another observable.
 *
 * @param <T>
 *            the return value type of the wrapped observable.
 */
public final class OperatorAsObservable<T> implements Operator<T, T> {
    /** Lazy initialization via inner-class holder. */
    static final class Holder {
        /** A singleton instance. */
        static final OperatorAsObservable<Object> INSTANCE = new OperatorAsObservable<Object>();
    }
    /**
     * @param <T> the value type
     * @return a singleton instance of this stateless operator.
     */
    @SuppressWarnings("unchecked")
    public static <T> OperatorAsObservable<T> instance() {
        return (OperatorAsObservable<T>)Holder.INSTANCE;
    }
    OperatorAsObservable() {
        // singleton
    }

    @Override
    public Subscriber<? super T> call(Subscriber<? super T> s) {
        return s;
    }

}
