/**
* Copyright 2016 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.*;
import rx.
Observable.
OnSubscribe;
/**
* Holds a singleton instance of a never Observable which is stateless doesn't
* call any of the Subscriber's methods.
*/
public enum
NeverObservableHolder implements
OnSubscribe<
Object> {
INSTANCE
;
/** The singleton instance. */
static final
Observable<
Object>
NEVER =
Observable.
unsafeCreate(
INSTANCE);
/**
* Returns a type-corrected singleton instance of the never Observable.
* @param <T> the value type
* @return a type-corrected singleton instance of the never Observable.
*/
@
SuppressWarnings("unchecked")
public static <T>
Observable<T>
instance() {
return (
Observable<T>)
NEVER;
}
@
Override
public void
call(
Subscriber<? super
Object>
child) {
// deliberately no op
}
}