constrained sender_decompose to be only used with basic_sender

Author: dietmarkuehl

include/beman/execution/detail/basic_sender.hpp

@@ -67,6 +67,7 @@ template <typename Tag, typename Data, typename... Child>
 struct basic_sender : ::beman::execution::detail::product_type<Tag, Data, Child...> {
     //-dk:TODO friend struct ::beman::execution::detail::connect_t;
     using sender_concept = ::beman::execution::sender_t;
+    using is_basic_sender_tag = void; //-dk:TODO need a better way to detect this is a basic sender
     using indices_for    = ::std::index_sequence_for<Child...>;
     static constexpr ::std::integral_constant<::std::size_t, sizeof...(Child) + 2> size{};
 

include/beman/execution/detail/inline_scheduler.hpp

@@ -60,11 +60,6 @@ struct inline_scheduler {
 
         static constexpr auto get_env() noexcept -> env { return {}; }
 
-        template <typename, typename...>
-        static consteval auto get_completion_signatures() noexcept -> completion_signatures {
-            return {};
-        }
-
         template <::beman::execution::receiver Rcvr>
         auto connect(Rcvr&& receiver) noexcept(::std::is_nothrow_constructible_v<::std::remove_cvref_t<Rcvr>, Rcvr>)
             -> state<Rcvr> {

include/beman/execution/detail/sender_decompose.hpp

@@ -51,7 +51,10 @@ auto get_sender_data(Sender&& sender) {
     using sender_type = ::std::remove_cvref_t<Sender>;
     static constexpr ::beman::execution::detail::sender_convert_to_any_t at{};
 
-    if constexpr (requires {
+    if constexpr (!requires { typename sender_type::is_basic_sender_tag; }) {
+        return ::beman::execution::detail::sender_meta<void, void, Sender>{};
+    }
+    else if constexpr (requires {
                       sender.template get<0>();
                       sender.size();
                   })

tests/beman/execution/exec-domain-default.test.cpp

@@ -63,6 +63,7 @@ struct tag {
 template <bool Noexcept>
 struct tagged_sender {
     using sender_concept = test_std::sender_t;
+    using is_basic_sender_tag = void;
     tag<Noexcept> t{};
     int           value{17};
     int           args{};

tests/beman/execution/exec-snd-concepts.test.cpp

@@ -34,24 +34,28 @@ struct own_sender {
 struct tag_t {};
 struct tagged_sender {
     using sender_concept = test_std::sender_t;
+    using is_basic_sender_tag = void;
     tag_t tag;
     int   data;
 };
 struct tagged_sender1 {
     using sender_concept = test_std::sender_t;
+    using is_basic_sender_tag = void;
     tag_t tag;
     int   data;
     int   child1;
 };
 struct tagged_sender2 {
     using sender_concept = test_std::sender_t;
+    using is_basic_sender_tag = void;
     tag_t tag;
     int   data;
     int   child1;
     int   child2;
 };
 struct tagged_sender3 {
     using sender_concept = test_std::sender_t;
+    using is_basic_sender_tag = void;
     tag_t tag;
     int   data;
     int   child1;
@@ -60,6 +64,7 @@ struct tagged_sender3 {
 };
 struct tagged_sender4 {
     using sender_concept = test_std::sender_t;
+    using is_basic_sender_tag = void;
     tag_t tag;
     int   data;
     int   child1;
@@ -69,18 +74,23 @@ struct tagged_sender4 {
 };
 struct product_sender0 : test_detail::product_type<tag_t, int> {
     using sender_concept = test_std::sender_t;
+    using is_basic_sender_tag = void;
 };
 struct product_sender1 : test_detail::product_type<tag_t, int, int> {
     using sender_concept = test_std::sender_t;
+    using is_basic_sender_tag = void;
 };
 struct product_sender2 : test_detail::product_type<tag_t, int, int, int> {
     using sender_concept = test_std::sender_t;
+    using is_basic_sender_tag = void;
 };
 struct product_sender3 : test_detail::product_type<tag_t, int, int, int, int> {
     using sender_concept = test_std::sender_t;
+    using is_basic_sender_tag = void;
 };
 struct product_sender4 : test_detail::product_type<tag_t, int, int, int, int, int> {
     using sender_concept = test_std::sender_t;
+    using is_basic_sender_tag = void;
 };
 
 // -------------------------------------------------------------------------

tests/beman/execution/exec-snd-expos.test.cpp

@@ -113,6 +113,7 @@ struct operation_state : test_detail::immovable {
 struct sender0 {
     struct env {};
     using sender_concept = test_std::sender_t;
+    using is_basic_sender_tag = void;
     using indices_for    = ::std::index_sequence_for<>;
     tag  t{};
     int* data{};
@@ -125,6 +126,7 @@ struct sender0 {
 
 struct sender1 {
     using sender_concept = test_std::sender_t;
+    using is_basic_sender_tag = void;
     using indices_for    = ::std::index_sequence_for<sender0>;
     tag     t{};
     int*    data{};
@@ -137,6 +139,7 @@ struct sender1 {
 
 struct sender2 {
     using sender_concept = test_std::sender_t;
+    using is_basic_sender_tag = void;
     using indices_for    = ::std::index_sequence_for<sender0, sender0>;
     tag     t{};
     int*    data{};
@@ -150,6 +153,7 @@ struct sender2 {
 
 struct sender3 {
     using sender_concept = test_std::sender_t;
+    using is_basic_sender_tag = void;
     using indices_for    = ::std::index_sequence_for<sender0, sender0, sender0>;
     tag     t{};
     int*    data{};
@@ -164,6 +168,7 @@ struct sender3 {
 
 struct sender4 {
     using sender_concept = test_std::sender_t;
+    using is_basic_sender_tag = void;
     using indices_for    = ::std::index_sequence_for<sender0, sender0, sender0, sender0>;
     tag     t{};
     int*    data{};
@@ -547,28 +552,33 @@ auto test_default_impls_get_state() -> void {
         auto operator==(const data&) const -> bool = default;
     };
     struct local_sender0 {
+        using is_basic_sender_tag = void;
         local_tag t{};
         data      d{1, 2};
     };
     struct local_sender1 {
+        using is_basic_sender_tag = void;
         local_tag t{};
         data      d{1, 2};
         int       i1{};
     };
     struct local_sender2 {
+        using is_basic_sender_tag = void;
         local_tag t{};
         data      d{1, 2};
         int       i1{};
         int       i2{};
     };
     struct local_sender3 {
+        using is_basic_sender_tag = void;
         local_tag t{};
         data      d{1, 2};
         int       i1{};
         int       i2{};
         int       i3{};
     };
     struct local_sender4 {
+        using is_basic_sender_tag = void;
         local_tag t{};
         data      d{1, 2};
         int       i1{};
@@ -665,6 +675,7 @@ auto test_state_type() -> void {
     };
     struct state {};
     struct sender {
+        using is_basic_sender_tag = void;
         local_tag t;
         state     s;
     };
@@ -679,6 +690,7 @@ auto test_basic_state() -> void {
     };
     struct data {};
     struct local_sender {
+        using is_basic_sender_tag = void;
         local_tag t;
         data      d;
     };
@@ -717,10 +729,12 @@ auto test_env_type() -> void {
     struct data {};
     struct local_env {};
     struct local_sender {
+        using is_basic_sender_tag = void;
         local_tag t;
         data      d;
     };
     struct sender_with_env {
+        using is_basic_sender_tag = void;
         local_tag t;
         data      d;
         auto      get_env() const noexcept -> local_env { return {}; }
@@ -750,6 +764,7 @@ auto test_basic_receiver() -> void {
         auto operator==(const err&) const -> bool = default;
     };
     struct local_sender {
+        using is_basic_sender_tag = void;
         local_tag t{};
         data      d{};
     };
@@ -1099,6 +1114,7 @@ struct basic_sender_tag {
 struct data {};
 struct tagged_sender : test_detail::product_type<basic_sender_tag, data, sender0> {
     using sender_concept = test_std::sender_t;
+    using is_basic_sender_tag = void;
 };
 } // namespace
 namespace std {

tests/beman/execution/exec-snd-transform.test.cpp

@@ -45,6 +45,7 @@ struct tag {
 template <int I>
 struct sender {
     using sender_concept = test_std::sender_t;
+    using is_basic_sender_tag = void;
     using index_type     = std::integral_constant<int, I>;
     tag<I> t;
     int    value{};