feat add rxcpp

3party/rxcpp/operators/rx-distinct.hpp

@@ -0,0 +1,119 @@
+// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved. See License.txt in the project root for license information.
+
+#pragma once
+
+/*! \file rx-distinct.hpp
+
+    \brief For each item from this observable, filter out repeated values and emit only items that have not already been emitted.
+
+    \return Observable that emits those items from the source observable that are distinct.
+
+    \note istinct keeps an unordered_set<T> of past values. Due to an issue in multiple implementations of std::hash<T>, rxcpp maintains a whitelist of hashable types. new types can be added by specializing rxcpp::filtered_hash<T>
+
+    \sample
+    \snippet distinct.cpp distinct sample
+    \snippet output.txt distinct sample
+*/
+
+#if !defined(RXCPP_OPERATORS_RX_DISTINCT_HPP)
+#define RXCPP_OPERATORS_RX_DISTINCT_HPP
+
+#include "../rx-includes.hpp"
+
+namespace rxcpp {
+
+namespace operators {
+
+namespace detail {
+
+template<class... AN>
+struct distinct_invalid_arguments {};
+
+template<class... AN>
+struct distinct_invalid : public rxo::operator_base<distinct_invalid_arguments<AN...>> {
+    using type = observable<distinct_invalid_arguments<AN...>, distinct_invalid<AN...>>;
+};
+template<class... AN>
+using distinct_invalid_t = typename distinct_invalid<AN...>::type;
+
+template<class T>
+struct distinct
+{
+    typedef rxu::decay_t<T> source_value_type;
+
+    template<class Subscriber>
+    struct distinct_observer
+    {
+        typedef distinct_observer<Subscriber> this_type;
+        typedef source_value_type value_type;
+        typedef rxu::decay_t<Subscriber> dest_type;
+        typedef observer<value_type, this_type> observer_type;
+        dest_type dest;
+        mutable std::unordered_set<source_value_type, rxcpp::filtered_hash<source_value_type>> remembered;
+
+        distinct_observer(dest_type d)
+                : dest(d)
+        {
+        }
+        void on_next(source_value_type v) const {
+            if (remembered.empty() || remembered.count(v) == 0) {
+                remembered.insert(v);
+                dest.on_next(v);
+            }
+        }
+        void on_error(rxu::error_ptr e) const {
+            dest.on_error(e);
+        }
+        void on_completed() const {
+            dest.on_completed();
+        }
+
+        static subscriber<value_type, observer<value_type, this_type>> make(dest_type d) {
+            return make_subscriber<value_type>(d, this_type(d));
+        }
+    };
+
+    template<class Subscriber>
+    auto operator()(Subscriber dest) const
+    -> decltype(distinct_observer<Subscriber>::make(std::move(dest))) {
+        return      distinct_observer<Subscriber>::make(std::move(dest));
+    }
+};
+
+}
+
+/*! @copydoc rx-distinct.hpp
+*/
+template<class... AN>
+auto distinct(AN&&... an)
+    ->     operator_factory<distinct_tag, AN...> {
+    return operator_factory<distinct_tag, AN...>(std::make_tuple(std::forward<AN>(an)...));
+}
+
+}
+
+template<>
+struct member_overload<distinct_tag>
+{
+    template<class Observable,
+            class SourceValue = rxu::value_type_t<Observable>,
+            class Enabled = rxu::enable_if_all_true_type_t<
+                is_observable<Observable>,
+                is_hashable<SourceValue>>,
+            class Distinct = rxo::detail::distinct<SourceValue>>
+    static auto member(Observable&& o)
+    -> decltype(o.template lift<SourceValue>(Distinct())) {
+        return  o.template lift<SourceValue>(Distinct());
+    }
+
+    template<class... AN>
+    static operators::detail::distinct_invalid_t<AN...> member(AN...) {
+        std::terminate();
+        return {};
+        static_assert(sizeof...(AN) == 10000, "distinct takes no arguments");
+    }
+};
+
+}
+
+#endif