decouple take from observable

4 files changed, 75 insertions, 44 deletions

diff --git a/Rx/v2/src/rxcpp/operators/rx-take.hpp b/Rx/v2/src/rxcpp/operators/rx-take.hpp
index c7259a3..054c136 100644
--- a/Rx/v2/src/rxcpp/operators/rx-take.hpp
+++ b/Rx/v2/src/rxcpp/operators/rx-take.hpp
@@ -2,6 +2,21 @@
 
 #pragma once
 
+/*! \file rx-take.hpp
+
+    \brief For the first count items from this observable emit them from the new observable that is returned.
+
+    \tparam Count the type of the items counter.
+
+    \param t the number of items to take.
+
+    \return An observable that emits only the first t items emitted by the source Observable, or all of the items from the source observable if that observable emits fewer than t items.
+
+    \sample
+    \snippet take.cpp take sample
+    \snippet output.txt take sample
+*/
+
 #if !defined(RXCPP_OPERATORS_RX_TAKE_HPP)
 #define RXCPP_OPERATORS_RX_TAKE_HPP
 
@@ -13,6 +28,16 @@ namespace operators {
 
 namespace detail {
 
+template<class... AN>
+struct take_invalid_arguments {};
+
+template<class... AN>
+struct take_invalid : public rxo::operator_base<take_invalid_arguments<AN...>> {
+    using type = observable<take_invalid_arguments<AN...>, take_invalid<AN...>>;
+};
+template<class... AN>
+using take_invalid_t = typename take_invalid<AN...>::type;
+
 template<class T, class Observable, class Count>
 struct take : public operator_base<T>
 {
@@ -100,31 +125,41 @@ struct take : public operator_base<T>
     }
 };
 
-template<class T>
-class take_factory
-{
-    typedef rxu::decay_t<T> count_type;
-    count_type count;
-public:
-    take_factory(count_type t) : count(std::move(t)) {}
-    template<class Observable>
-    auto operator()(Observable&& source)
-        ->      observable<rxu::value_type_t<rxu::decay_t<Observable>>,   take<rxu::value_type_t<rxu::decay_t<Observable>>, Observable, count_type>> {
-        return  observable<rxu::value_type_t<rxu::decay_t<Observable>>,   take<rxu::value_type_t<rxu::decay_t<Observable>>, Observable, count_type>>(
-                                                                          take<rxu::value_type_t<rxu::decay_t<Observable>>, Observable, count_type>(std::forward<Observable>(source), count));
-    }
-};
-
 }
 
-template<class T>
-auto take(T&& t)
-    ->      detail::take_factory<T> {
-    return  detail::take_factory<T>(std::forward<T>(t));
+/*! @copydoc rx-take.hpp
+*/
+template<class... AN>
+auto take(AN&&... an)
+    ->     operator_factory<take_tag, AN...> {
+    return operator_factory<take_tag, AN...>(std::make_tuple(std::forward<AN>(an)...));
 }
 
 }
 
+template<>
+struct member_overload<take_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 Take = rxo::detail::take<SourceValue, rxu::decay_t<Observable>, rxu::decay_t<Count>>,
+        class Value = rxu::value_type_t<Take>,
+        class Result = observable<Value, Take>>
+    static Result member(Observable&& o, Count&& c) {
+        return Result(Take(std::forward<Observable>(o), std::forward<Count>(c)));
+    }
+
+    template<class... AN>
+    static operators::detail::take_invalid_t<AN...> member(AN...) {
+        std::terminate();
+        return {};
+        static_assert(sizeof...(AN) == 10000, "take takes (optional Count)");
+    }
+};
+
 }
 
 #endif
diff --git a/Rx/v2/src/rxcpp/rx-includes.hpp b/Rx/v2/src/rxcpp/rx-includes.hpp
index 35a14bb..38607eb 100644
--- a/Rx/v2/src/rxcpp/rx-includes.hpp
+++ b/Rx/v2/src/rxcpp/rx-includes.hpp
@@ -202,6 +202,7 @@
 #include "operators/rx-repeat.hpp"
 #include "operators/rx-retry.hpp"
 #include "operators/rx-sequence_equal.hpp"
+#include "operators/rx-take.hpp"
 #include "operators/rx-take_while.hpp"
 #include "operators/rx-timeout.hpp"
 #include "operators/rx-time_interval.hpp"
diff --git a/Rx/v2/src/rxcpp/rx-observable.hpp b/Rx/v2/src/rxcpp/rx-observable.hpp
index 761aa7f..bdd847a 100644
--- a/Rx/v2/src/rxcpp/rx-observable.hpp
+++ b/Rx/v2/src/rxcpp/rx-observable.hpp
@@ -2517,26 +2517,15 @@ public:
                                 rxo::detail::skip_until<T, this_type, TriggerSource, Coordination>(*this, std::forward<TriggerSource>(t), std::forward<Coordination>(cn)));
     }
 
-    /*! For the first count items from this observable emit them from the new observable that is returned.
-
-        \tparam Count  the type of the items counter
-
-        \param t  the number of items to take
-
-        \return  An observable that emits only the first t items emitted by the source Observable, or all of the items from the source observable if that observable emits fewer than t items.
-
-        \sample
-        \snippet take.cpp take sample
-        \snippet output.txt take sample
-    */
-    template<class Count>
-    auto take(Count t) const
+    /*! @copydoc rx-take.hpp
+     */
+    template<class... AN>
+    auto take(AN... an) const
         /// \cond SHOW_SERVICE_MEMBERS
-        ->      observable<T,   rxo::detail::take<T, this_type, Count>>
+        -> decltype(observable_member(take_tag{}, *(this_type*)nullptr, std::forward<AN>(an)...))
         /// \endcond
     {
-        return  observable<T,   rxo::detail::take<T, this_type, Count>>(
-                                rxo::detail::take<T, this_type, Count>(*this, t));
+        return      observable_member(take_tag{},                *this, std::forward<AN>(an)...);
     }
 
     /*! Emit only the final t items emitted by the source Observable.
diff --git a/Rx/v2/src/rxcpp/rx-operators.hpp b/Rx/v2/src/rxcpp/rx-operators.hpp
index 2ecea1e..0d1a2b4 100644
--- a/Rx/v2/src/rxcpp/rx-operators.hpp
+++ b/Rx/v2/src/rxcpp/rx-operators.hpp
@@ -119,7 +119,6 @@ public:
 #include "operators/rx-subscribe_on.hpp"
 #include "operators/rx-switch_if_empty.hpp"
 #include "operators/rx-switch_on_next.hpp"
-#include "operators/rx-take.hpp"
 #include "operators/rx-take_last.hpp"
 #include "operators/rx-take_until.hpp"
 #include "operators/rx-tap.hpp"
@@ -260,13 +259,6 @@ struct average_tag : reduce_tag {};
 struct min_tag : reduce_tag {};
 struct max_tag : reduce_tag {};
 
-struct take_while_tag {
-    template<class Included>
-    struct include_header{
-        static_assert(Included::value, "missing include: please #include <rxcpp/operators/rx-take_while.hpp>");
-    };
-};
-
 struct pairwise_tag {
     template<class Included>
     struct include_header{
@@ -295,6 +287,20 @@ struct sequence_equal_tag {
     };
 };
 
+struct take_tag {
+    template<class Included>
+    struct include_header{
+        static_assert(Included::value, "missing include: please #include <rxcpp/operators/rx-take.hpp>");
+    };
+};
+
+struct take_while_tag {
+    template<class Included>
+    struct include_header{
+        static_assert(Included::value, "missing include: please #include <rxcpp/operators/rx-take_while.hpp>");
+    };
+};
+
 struct timeout_tag {
     template<class Included>
     struct include_header{