269 lines
9.9 KiB
C++
269 lines
9.9 KiB
C++
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// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved. See License.txt in the project root for license information.
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#pragma once
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/*! \file rx-debounce.hpp
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\brief Return an observable that emits an item if a particular timespan has passed without emitting another item from the source observable.
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\tparam Duration the type of the time interval
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\tparam Coordination the type of the scheduler
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\param period the period of time to suppress any emitted items
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\param coordination the scheduler to manage timeout for each event
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\return Observable that emits an item if a particular timespan has passed without emitting another item from the source observable.
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\sample
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\snippet debounce.cpp debounce sample
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\snippet output.txt debounce sample
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*/
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#if !defined(RXCPP_OPERATORS_RX_DEBOUNCE_HPP)
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#define RXCPP_OPERATORS_RX_DEBOUNCE_HPP
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#include "../rx-includes.hpp"
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namespace rxcpp {
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namespace operators {
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namespace detail {
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template<class... AN>
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struct debounce_invalid_arguments {};
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template<class... AN>
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struct debounce_invalid : public rxo::operator_base<debounce_invalid_arguments<AN...>> {
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using type = observable<debounce_invalid_arguments<AN...>, debounce_invalid<AN...>>;
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};
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template<class... AN>
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using debounce_invalid_t = typename debounce_invalid<AN...>::type;
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template<class T, class Duration, class Coordination>
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struct debounce
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{
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typedef rxu::decay_t<T> source_value_type;
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typedef rxu::decay_t<Coordination> coordination_type;
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typedef typename coordination_type::coordinator_type coordinator_type;
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typedef rxu::decay_t<Duration> duration_type;
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struct debounce_values
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{
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debounce_values(duration_type p, coordination_type c)
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: period(p)
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, coordination(c)
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{
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}
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duration_type period;
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coordination_type coordination;
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};
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debounce_values initial;
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debounce(duration_type period, coordination_type coordination)
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: initial(period, coordination)
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{
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}
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template<class Subscriber>
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struct debounce_observer
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{
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typedef debounce_observer<Subscriber> this_type;
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typedef rxu::decay_t<T> value_type;
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typedef rxu::decay_t<Subscriber> dest_type;
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typedef observer<T, this_type> observer_type;
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struct debounce_subscriber_values : public debounce_values
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{
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debounce_subscriber_values(composite_subscription cs, dest_type d, debounce_values v, coordinator_type c)
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: debounce_values(v)
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, cs(std::move(cs))
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, dest(std::move(d))
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, coordinator(std::move(c))
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, worker(coordinator.get_worker())
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, index(0)
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{
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}
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composite_subscription cs;
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dest_type dest;
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coordinator_type coordinator;
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rxsc::worker worker;
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mutable std::size_t index;
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mutable rxu::maybe<value_type> value;
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};
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typedef std::shared_ptr<debounce_subscriber_values> state_type;
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state_type state;
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debounce_observer(composite_subscription cs, dest_type d, debounce_values v, coordinator_type c)
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: state(std::make_shared<debounce_subscriber_values>(debounce_subscriber_values(std::move(cs), std::move(d), v, std::move(c))))
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{
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auto localState = state;
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auto disposer = [=](const rxsc::schedulable&){
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localState->cs.unsubscribe();
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localState->dest.unsubscribe();
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localState->worker.unsubscribe();
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};
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auto selectedDisposer = on_exception(
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[&](){ return localState->coordinator.act(disposer); },
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localState->dest);
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if (selectedDisposer.empty()) {
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return;
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}
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localState->dest.add([=](){
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localState->worker.schedule(selectedDisposer.get());
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});
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localState->cs.add([=](){
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localState->worker.schedule(selectedDisposer.get());
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});
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}
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static std::function<void(const rxsc::schedulable&)> produce_item(std::size_t id, state_type state) {
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auto produce = [id, state](const rxsc::schedulable&) {
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if(id != state->index)
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return;
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state->dest.on_next(*state->value);
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state->value.reset();
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};
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auto selectedProduce = on_exception(
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[&](){ return state->coordinator.act(produce); },
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state->dest);
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if (selectedProduce.empty()) {
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return std::function<void(const rxsc::schedulable&)>();
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}
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return std::function<void(const rxsc::schedulable&)>(selectedProduce.get());
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}
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void on_next(T v) const {
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auto localState = state;
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auto work = [v, localState](const rxsc::schedulable&) {
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auto new_id = ++localState->index;
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auto produce_time = localState->worker.now() + localState->period;
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localState->value.reset(v);
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localState->worker.schedule(produce_time, produce_item(new_id, localState));
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};
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auto selectedWork = on_exception(
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[&](){return localState->coordinator.act(work);},
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localState->dest);
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if (selectedWork.empty()) {
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return;
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}
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localState->worker.schedule(selectedWork.get());
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}
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void on_error(rxu::error_ptr e) const {
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auto localState = state;
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auto work = [e, localState](const rxsc::schedulable&) {
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localState->dest.on_error(e);
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localState->value.reset();
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};
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auto selectedWork = on_exception(
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[&](){ return localState->coordinator.act(work); },
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localState->dest);
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if (selectedWork.empty()) {
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return;
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}
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localState->worker.schedule(selectedWork.get());
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}
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void on_completed() const {
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auto localState = state;
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auto work = [localState](const rxsc::schedulable&) {
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if(!localState->value.empty()) {
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localState->dest.on_next(*localState->value);
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}
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localState->dest.on_completed();
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};
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auto selectedWork = on_exception(
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[&](){ return localState->coordinator.act(work); },
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localState->dest);
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if (selectedWork.empty()) {
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return;
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}
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localState->worker.schedule(selectedWork.get());
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}
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static subscriber<T, observer_type> make(dest_type d, debounce_values v) {
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auto cs = composite_subscription();
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auto coordinator = v.coordination.create_coordinator();
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return make_subscriber<T>(cs, observer_type(this_type(cs, std::move(d), std::move(v), std::move(coordinator))));
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}
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};
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template<class Subscriber>
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auto operator()(Subscriber dest) const
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-> decltype(debounce_observer<Subscriber>::make(std::move(dest), initial)) {
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return debounce_observer<Subscriber>::make(std::move(dest), initial);
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}
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};
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}
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/*! @copydoc rx-debounce.hpp
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*/
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template<class... AN>
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auto debounce(AN&&... an)
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-> operator_factory<debounce_tag, AN...> {
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return operator_factory<debounce_tag, AN...>(std::make_tuple(std::forward<AN>(an)...));
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}
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}
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template<>
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struct member_overload<debounce_tag>
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{
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template<class Observable, class Duration,
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class Enabled = rxu::enable_if_all_true_type_t<
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is_observable<Observable>,
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rxu::is_duration<Duration>>,
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class SourceValue = rxu::value_type_t<Observable>,
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class Debounce = rxo::detail::debounce<SourceValue, rxu::decay_t<Duration>, identity_one_worker>>
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static auto member(Observable&& o, Duration&& d)
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-> decltype(o.template lift<SourceValue>(Debounce(std::forward<Duration>(d), identity_current_thread()))) {
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return o.template lift<SourceValue>(Debounce(std::forward<Duration>(d), identity_current_thread()));
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}
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template<class Observable, class Coordination, class Duration,
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class Enabled = rxu::enable_if_all_true_type_t<
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is_observable<Observable>,
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is_coordination<Coordination>,
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rxu::is_duration<Duration>>,
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class SourceValue = rxu::value_type_t<Observable>,
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class Debounce = rxo::detail::debounce<SourceValue, rxu::decay_t<Duration>, rxu::decay_t<Coordination>>>
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static auto member(Observable&& o, Coordination&& cn, Duration&& d)
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-> decltype(o.template lift<SourceValue>(Debounce(std::forward<Duration>(d), std::forward<Coordination>(cn)))) {
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return o.template lift<SourceValue>(Debounce(std::forward<Duration>(d), std::forward<Coordination>(cn)));
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}
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template<class Observable, class Coordination, class Duration,
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class Enabled = rxu::enable_if_all_true_type_t<
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is_observable<Observable>,
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is_coordination<Coordination>,
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rxu::is_duration<Duration>>,
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class SourceValue = rxu::value_type_t<Observable>,
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class Debounce = rxo::detail::debounce<SourceValue, rxu::decay_t<Duration>, rxu::decay_t<Coordination>>>
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static auto member(Observable&& o, Duration&& d, Coordination&& cn)
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-> decltype(o.template lift<SourceValue>(Debounce(std::forward<Duration>(d), std::forward<Coordination>(cn)))) {
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return o.template lift<SourceValue>(Debounce(std::forward<Duration>(d), std::forward<Coordination>(cn)));
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}
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template<class... AN>
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static operators::detail::debounce_invalid_t<AN...> member(const AN&...) {
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std::terminate();
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return {};
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static_assert(sizeof...(AN) == 10000, "debounce takes (optional Coordination, required Duration) or (required Duration, optional Coordination)");
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}
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};
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}
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#endif
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