277 lines
		
	
	
		
			10 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			277 lines
		
	
	
		
			10 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
| // Copyright (c) Microsoft Open Technologies, Inc. All rights reserved. See License.txt in the project root for license information.
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| 
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| #pragma once
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| 
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| /*! \file rx-skip_until.hpp
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| 
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|     \brief Make new observable with items skipped until on_next occurs on the trigger observable or until the specified time.
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|            skip_until takes (TriggerObservable, optional Coordination) or (TimePoint, optional Coordination)
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| 
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|     \tparam  TriggerSource  the type of the trigger observable.
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|     \tparam  Coordination   the type of the scheduler (optional).
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| 
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|     \param  t  an observable that has to emit an item before the source observable's elements begin to be mirrored by the resulting observable.
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|     \param  cn  the scheduler to use for scheduling the items (optional).
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| 
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|     \return  An observable that skips items from the source observable until the second observable emits an item or the time runs out, then emits the remaining items.
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| 
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|     \sample
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|     \snippet skip_until.cpp skip_until sample
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|     \snippet output.txt skip_until sample
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| 
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|     \sample
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|     \snippet skip_until.cpp threaded skip_until sample
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|     \snippet output.txt threaded skip_until sample
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| */
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| 
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| #if !defined(RXCPP_OPERATORS_RX_SKIP_UNTIL_HPP)
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| #define RXCPP_OPERATORS_RX_SKIP_UNTIL_HPP
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| 
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| #include "../rx-includes.hpp"
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| 
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| namespace rxcpp {
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| 
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| namespace operators {
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| 
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| namespace detail {
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| 
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| template<class... AN>
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| struct skip_until_invalid_arguments {};
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| 
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| template<class... AN>
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| struct skip_until_invalid : public rxo::operator_base<skip_until_invalid_arguments<AN...>> {
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|     using type = observable<skip_until_invalid_arguments<AN...>, skip_until_invalid<AN...>>;
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| };
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| template<class... AN>
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| using skip_until_invalid_t = typename skip_until_invalid<AN...>::type;
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| 
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| template<class T, class Observable, class TriggerObservable, class Coordination>
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| struct skip_until : public operator_base<T>
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| {
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|     typedef rxu::decay_t<Observable> source_type;
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|     typedef rxu::decay_t<TriggerObservable> trigger_source_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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|     struct values
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|     {
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|         values(source_type s, trigger_source_type t, coordination_type sf)
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|             : source(std::move(s))
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|             , trigger(std::move(t))
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|             , coordination(std::move(sf))
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|         {
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|         }
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|         source_type source;
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|         trigger_source_type trigger;
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|         coordination_type coordination;
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|     };
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|     values initial;
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| 
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|     skip_until(source_type s, trigger_source_type t, coordination_type sf)
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|         : initial(std::move(s), std::move(t), std::move(sf))
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|     {
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|     }
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| 
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|     struct mode
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|     {
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|         enum type {
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|             skipping,  // no messages from trigger
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|             clear,     // trigger completed
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|             triggered, // trigger sent on_next
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|             errored,   // error either on trigger or on observable
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|             stopped    // observable completed
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|         };
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|     };
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| 
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|     template<class Subscriber>
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|     void on_subscribe(Subscriber s) const {
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| 
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|         typedef Subscriber output_type;
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|         struct state_type
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|             : public std::enable_shared_from_this<state_type>
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|             , public values
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|         {
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|             state_type(const values& i, coordinator_type coor, const output_type& oarg)
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|                 : values(i)
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|                 , mode_value(mode::skipping)
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|                 , coordinator(std::move(coor))
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|                 , out(oarg)
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|             {
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|                 out.add(trigger_lifetime);
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|                 out.add(source_lifetime);
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|             }
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|             typename mode::type mode_value;
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|             composite_subscription trigger_lifetime;
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|             composite_subscription source_lifetime;
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|             coordinator_type coordinator;
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|             output_type out;
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|         };
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| 
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|         auto coordinator = initial.coordination.create_coordinator();
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| 
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|         // take a copy of the values for each subscription
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|         auto state = std::make_shared<state_type>(initial, std::move(coordinator), std::move(s));
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| 
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|         auto trigger = on_exception(
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|             [&](){return state->coordinator.in(state->trigger);},
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|             state->out);
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|         if (trigger.empty()) {
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|             return;
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|         }
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| 
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|         auto source = on_exception(
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|             [&](){return state->coordinator.in(state->source);},
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|             state->out);
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|         if (source.empty()) {
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|             return;
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|         }
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| 
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|         auto sinkTrigger = make_subscriber<typename trigger_source_type::value_type>(
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|         // share parts of subscription
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|             state->out,
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|         // new lifetime
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|             state->trigger_lifetime,
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|         // on_next
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|             [state](const typename trigger_source_type::value_type&) {
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|                 if (state->mode_value != mode::skipping) {
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|                     return;
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|                 }
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|                 state->mode_value = mode::triggered;
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|                 state->trigger_lifetime.unsubscribe();
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|             },
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|         // on_error
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|             [state](rxu::error_ptr e) {
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|                 if (state->mode_value != mode::skipping) {
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|                     return;
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|                 }
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|                 state->mode_value = mode::errored;
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|                 state->out.on_error(e);
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|             },
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|         // on_completed
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|             [state]() {
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|                 if (state->mode_value != mode::skipping) {
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|                     return;
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|                 }
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|                 state->mode_value = mode::clear;
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|                 state->trigger_lifetime.unsubscribe();
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|             }
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|         );
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|         auto selectedSinkTrigger = on_exception(
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|             [&](){return state->coordinator.out(sinkTrigger);},
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|             state->out);
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|         if (selectedSinkTrigger.empty()) {
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|             return;
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|         }
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|         trigger->subscribe(std::move(selectedSinkTrigger.get()));
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| 
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|         source.get().subscribe(
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|         // split subscription lifetime
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|             state->source_lifetime,
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|         // on_next
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|             [state](T t) {
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|                 if (state->mode_value != mode::triggered) {
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|                     return;
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|                 }
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|                 state->out.on_next(t);
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|             },
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|         // on_error
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|             [state](rxu::error_ptr e) {
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|                 if (state->mode_value > mode::triggered) {
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|                     return;
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|                 }
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|                 state->mode_value = mode::errored;
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|                 state->out.on_error(e);
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|             },
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|         // on_completed
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|             [state]() {
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|                 if (state->mode_value != mode::triggered) {
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|                     return;
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|                 }
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|                 state->mode_value = mode::stopped;
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|                 state->out.on_completed();
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|             }
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|         );
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|     }
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| };
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| 
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| }
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| 
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| /*! @copydoc rx-skip_until.hpp
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| */
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| template<class... AN>
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| auto skip_until(AN&&... an)
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|     ->     operator_factory<skip_until_tag, AN...> {
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|     return operator_factory<skip_until_tag, AN...>(std::make_tuple(std::forward<AN>(an)...));
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| }
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| 
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| }
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| 
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| template<>
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| struct member_overload<skip_until_tag>
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| {
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|     template<class Observable, class TimePoint,
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|         class Enabled = rxu::enable_if_all_true_type_t<
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|             is_observable<Observable>,
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|             std::is_convertible<TimePoint, rxsc::scheduler::clock_type::time_point>>,
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|         class SourceValue = rxu::value_type_t<Observable>,
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|         class Timer = typename rxu::defer_type<rxs::detail::timer, identity_one_worker>::type,
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|         class TimerValue = rxu::value_type_t<Timer>,
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|         class TriggerObservable = observable<TimerValue, Timer>,
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|         class SkipUntil = rxo::detail::skip_until<SourceValue, rxu::decay_t<Observable>, TriggerObservable, identity_one_worker>,
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|         class Value = rxu::value_type_t<SkipUntil>,
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|         class Result = observable<Value, SkipUntil>>
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|     static Result member(Observable&& o, TimePoint&& when) {
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|         auto cn = identity_current_thread();
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|         return Result(SkipUntil(std::forward<Observable>(o), rxs::timer(std::forward<TimePoint>(when), cn), cn));
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|     }
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| 
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|     template<class Observable, class TimePoint, class Coordination,
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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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|             std::is_convertible<TimePoint, rxsc::scheduler::clock_type::time_point>>,
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|         class SourceValue = rxu::value_type_t<Observable>,
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|         class Timer = typename rxu::defer_type<rxs::detail::timer, rxu::decay_t<Coordination>>::type,
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|         class TimerValue = rxu::value_type_t<Timer>,
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|         class TriggerObservable = observable<TimerValue, Timer>,
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|         class SkipUntil = rxo::detail::skip_until<SourceValue, rxu::decay_t<Observable>, TriggerObservable, rxu::decay_t<Coordination>>,
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|         class Value = rxu::value_type_t<SkipUntil>,
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|         class Result = observable<Value, SkipUntil>>
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|     static Result member(Observable&& o, TimePoint&& when, Coordination cn) {
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|         return Result(SkipUntil(std::forward<Observable>(o), rxs::timer(std::forward<TimePoint>(when), cn), cn));
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|     }
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| 
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|     template<class Observable, class TriggerObservable,
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|         class Enabled = rxu::enable_if_all_true_type_t<
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|             all_observables<Observable, TriggerObservable>>,
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|         class SourceValue = rxu::value_type_t<Observable>,
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|         class SkipUntil = rxo::detail::skip_until<SourceValue, rxu::decay_t<Observable>, rxu::decay_t<TriggerObservable>, identity_one_worker>,
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|         class Value = rxu::value_type_t<SkipUntil>,
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|         class Result = observable<Value, SkipUntil>>
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|     static Result member(Observable&& o, TriggerObservable&& t) {
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|         return Result(SkipUntil(std::forward<Observable>(o), std::forward<TriggerObservable>(t), identity_current_thread()));
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|     }
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| 
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|      template<class Observable, class TriggerObservable, class Coordination,
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|         class Enabled = rxu::enable_if_all_true_type_t<
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|             all_observables<Observable, TriggerObservable>,
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|             is_coordination<Coordination>>,
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|         class SourceValue = rxu::value_type_t<Observable>,
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|         class SkipUntil = rxo::detail::skip_until<SourceValue, rxu::decay_t<Observable>, rxu::decay_t<TriggerObservable>, rxu::decay_t<Coordination>>,
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|         class Value = rxu::value_type_t<SkipUntil>,
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|         class Result = observable<Value, SkipUntil>>
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|     static Result member(Observable&& o, TriggerObservable&& t, Coordination&& cn) {
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|         return Result(SkipUntil(std::forward<Observable>(o), std::forward<TriggerObservable>(t), std::forward<Coordination>(cn)));
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|     }
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| 
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|     template<class... AN>
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|     static operators::detail::skip_until_invalid_t<AN...> member(AN...) {
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|         std::terminate();
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|         return {};
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|         static_assert(sizeof...(AN) == 10000, "skip_until takes (TriggerObservable, optional Coordination) or (TimePoint, optional Coordination)");
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|     }
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| };
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| 
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| }
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| 
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| #endif
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