blob: 116d11f08857545f42a55467ffb4f0ee8b1205f1 [file] [log] [blame]
// Copyright (c) 2016, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
import 'dart:async';
/// Simple delegating wrapper around a [Stream].
/// Subclasses can override individual methods, or use this to expose only the
/// [Stream] methods of a subclass.
/// Note that this is identical to [StreamView] in `dart:async`. It's provided
/// under this name for consistency with other `Delegating*` classes.
class DelegatingStream<T> extends StreamView<T> {
DelegatingStream(Stream<T> stream) : super(stream);
/// Creates a wrapper which throws if [stream]'s events aren't instances of
/// `T`.
/// This soundly converts a [Stream] to a `Stream<T>`, regardless of its
/// original generic type, by asserting that its events are instances of `T`
/// whenever they're provided. If they're not, the stream throws a
/// [CastError].
static Stream<T> typed<T>(Stream stream) => stream.cast();