feat add rxcpp

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

@@ -0,0 +1,162 @@
+// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved. See License.txt in the project root for license information.
+
+#pragma once
+
+/*! \file rx-skip.hpp
+
+    \brief Make new observable with skipped first count items from this observable.
+
+    \tparam Count the type of the items counter
+
+    \param t the number of items to skip
+
+    \return An observable that is identical to the source observable except that it does not emit the first t items that the source observable emits.
+
+    \sample
+    \snippet skip.cpp skip sample
+    \snippet output.txt skip sample
+*/
+
+#if !defined(RXCPP_OPERATORS_RX_SKIP_HPP)
+#define RXCPP_OPERATORS_RX_SKIP_HPP
+
+#include "../rx-includes.hpp"
+
+namespace rxcpp {
+
+namespace operators {
+
+namespace detail {
+
+template<class... AN>
+struct skip_invalid_arguments {};
+
+template<class... AN>
+struct skip_invalid : public rxo::operator_base<skip_invalid_arguments<AN...>> {
+    using type = observable<skip_invalid_arguments<AN...>, skip_invalid<AN...>>;
+};
+
+template<class... AN>
+using skip_invalid_t = typename skip_invalid<AN...>::type;
+
+template<class T, class Observable, class Count>
+struct skip : public operator_base<T>
+{
+    typedef rxu::decay_t<Observable> source_type;
+    typedef rxu::decay_t<Count> count_type;
+    struct values
+    {
+        values(source_type s, count_type t)
+            : source(std::move(s))
+            , count(std::move(t))
+        {
+        }
+        source_type source;
+        count_type count;
+    };
+    values initial;
+
+    skip(source_type s, count_type t)
+        : initial(std::move(s), std::move(t))
+    {
+    }
+
+    struct mode
+    {
+        enum type {
+            skipping,  // ignore messages
+            triggered, // capture messages
+            errored,   // error occured
+            stopped    // observable completed
+        };
+    };
+
+    template<class Subscriber>
+    void on_subscribe(const Subscriber& s) const {
+
+        typedef Subscriber output_type;
+        struct state_type
+            : public std::enable_shared_from_this<state_type>
+            , public values
+        {
+            state_type(const values& i, const output_type& oarg)
+                : values(i)
+                , mode_value(i.count > 0 ? mode::skipping : mode::triggered)
+                , out(oarg)
+            {
+            }
+            typename mode::type mode_value;
+            output_type out;
+        };
+        // take a copy of the values for each subscription
+        auto state = std::make_shared<state_type>(initial, s);
+
+        composite_subscription source_lifetime;
+
+        s.add(source_lifetime);
+
+        state->source.subscribe(
+        // split subscription lifetime
+            source_lifetime,
+        // on_next
+            [state](T t) {
+                if (state->mode_value == mode::skipping) {
+                    if (--state->count == 0) {
+                        state->mode_value = mode::triggered;
+                    }
+                } else {
+                    state->out.on_next(t);
+                }
+            },
+        // on_error
+            [state](rxu::error_ptr e) {
+                state->mode_value = mode::errored;
+                state->out.on_error(e);
+            },
+        // on_completed
+            [state]() {
+                state->mode_value = mode::stopped;
+                state->out.on_completed();
+            }
+        );
+    }
+};
+
+}
+
+/*! @copydoc rx-skip.hpp
+*/
+template<class... AN>
+auto skip(AN&&... an)
+->     operator_factory<skip_tag, AN...> {
+    return operator_factory<skip_tag, AN...>(std::make_tuple(std::forward<AN>(an)...));
+}
+
+}
+
+template<>
+struct member_overload<skip_tag>
+{
+    template<class Observable,
+            class Count,
+            class Enabled = rxu::enable_if_all_true_type_t<
+            is_observable<Observable>>,
+            class SourceValue = rxu::value_type_t<Observable>,
+            class Skip = rxo::detail::skip<SourceValue, rxu::decay_t<Observable>, rxu::decay_t<Count>>,
+            class Value = rxu::value_type_t<Skip>,
+            class Result = observable<Value, Skip>>
+    static Result member(Observable&& o, Count&& c) {
+        return Result(Skip(std::forward<Observable>(o), std::forward<Count>(c)));
+    }
+
+    template<class... AN>
+    static operators::detail::skip_invalid_t<AN...> member(AN...) {
+        std::terminate();
+        return {};
+        static_assert(sizeof...(AN) == 10000, "skip takes (optional Count)");
+    }
+};
+
+}
+
+#endif