feat add rxcpp

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

@@ -0,0 +1,153 @@
+// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved. See License.txt in the project root for license information.
+
+#pragma once
+
+/*! \file rx-skip_last.hpp
+
+    \brief Make new observable with skipped last count items from this observable.
+
+    \tparam Count the type of the items counter.
+
+    \param  t the number of last items to skip.
+
+    \return  An observable that is identical to the source observable except that it does not emit the last t items that the source observable emits.
+
+    \sample
+    \snippet skip_last.cpp skip_last sample
+    \snippet output.txt skip_last sample
+*/
+
+#if !defined(RXCPP_OPERATORS_RX_SKIP_LAST_HPP)
+#define RXCPP_OPERATORS_RX_SKIP_LAST_HPP
+
+#include "../rx-includes.hpp"
+
+namespace rxcpp {
+
+namespace operators {
+
+namespace detail {
+
+template<class... AN>
+struct skip_last_invalid_arguments {};
+
+template<class... AN>
+struct skip_last_invalid : public rxo::operator_base<skip_last_invalid_arguments<AN...>> {
+    using type = observable<skip_last_invalid_arguments<AN...>, skip_last_invalid<AN...>>;
+};
+template<class... AN>
+using skip_last_invalid_t = typename skip_last_invalid<AN...>::type;
+
+template<class T, class Observable, class Count>
+struct skip_last : public operator_base<T>
+{
+    typedef rxu::decay_t<Observable> source_type;
+    typedef rxu::decay_t<Count> count_type;
+
+    typedef std::queue<T> queue_type;
+    typedef typename queue_type::size_type queue_size_type;
+
+    struct values
+    {
+        values(source_type s, count_type t)
+            : source(std::move(s))
+            , count(static_cast<queue_size_type>(t))
+        {
+        }
+        source_type source;
+        queue_size_type count;
+    };
+    values initial;
+
+    skip_last(source_type s, count_type t)
+        : initial(std::move(s), std::move(t))
+    {
+    }
+
+    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)
+                , out(oarg)
+            {
+            }
+            queue_type items;
+            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->count > 0) {
+                    if (state->items.size() == state->count) {
+                        state->out.on_next(std::move(state->items.front()));
+                        state->items.pop();
+                    }
+                    state->items.push(t);
+                } else {
+                    state->out.on_next(t);
+                }
+            },
+        // on_error
+            [state](rxu::error_ptr e) {
+                state->out.on_error(e);
+            },
+        // on_completed
+            [state]() {
+                state->out.on_completed();
+            }
+        );
+    }
+};
+
+}
+
+/*! @copydoc rx-skip_last.hpp
+*/
+template<class... AN>
+auto skip_last(AN&&... an)
+    ->     operator_factory<skip_last_tag, AN...> {
+    return operator_factory<skip_last_tag, AN...>(std::make_tuple(std::forward<AN>(an)...));
+}
+
+}
+
+template<>
+struct member_overload<skip_last_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 SkipLast = rxo::detail::skip_last<SourceValue, rxu::decay_t<Observable>, rxu::decay_t<Count>>,
+        class Value = rxu::value_type_t<SkipLast>,
+        class Result = observable<Value, SkipLast>>
+    static Result member(Observable&& o, Count&& c) {
+        return Result(SkipLast(std::forward<Observable>(o), std::forward<Count>(c)));
+    }
+
+    template<class... AN>
+    static operators::detail::skip_last_invalid_t<AN...> member(AN...) {
+        std::terminate();
+        return {};
+        static_assert(sizeof...(AN) == 10000, "skip_last takes (Count)");
+    }
+};
+
+}
+
+#endif