51 lines
1.5 KiB
C++
51 lines
1.5 KiB
C++
// Copyright (c) Facebook, Inc. and its affiliates.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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#pragma once
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#include "yarpl/observable/Observable.h"
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namespace yarpl {
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namespace observable {
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namespace details {
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template <typename T, typename ObservableFactory>
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class DeferObservable : public Observable<T> {
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static_assert(
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std::is_same<std::decay_t<ObservableFactory>, ObservableFactory>::value,
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"undecayed");
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public:
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template <typename F>
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explicit DeferObservable(F&& factory) : factory_(std::forward<F>(factory)) {}
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virtual std::shared_ptr<Subscription> subscribe(
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std::shared_ptr<Observer<T>> observer) {
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std::shared_ptr<Observable<T>> observable;
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try {
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observable = factory_();
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} catch (const std::exception& ex) {
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observable = Observable<T>::error(ex, std::current_exception());
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}
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return observable->subscribe(std::move(observer));
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}
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private:
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ObservableFactory factory_;
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};
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} // namespace details
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} // namespace observable
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} // namespace yarpl
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