fix stream senders/receivers and sequence senders

examples/nvexec/maxwell/snr.cuh

@@ -26,9 +26,13 @@
 #include <nvexec/multi_gpu_context.cuh>
 #else
 namespace nvexec {
-  struct stream_receiver_base { };
+  struct stream_receiver_base {
+    using receiver_concept = stdexec::receiver_t;
+  };
 
-  struct stream_sender_base { };
+  struct stream_sender_base {
+    using sender_concept = stdexec::sender_t;
+  };
 
   namespace detail {
     struct stream_op_state_base { };
@@ -187,13 +191,15 @@ namespace nvexec::STDEXEC_STREAM_DETAIL_NS { //
 namespace repeat_n_detail {
 
   template <class OpT>
-  class receiver_2_t : public stdexec::__receiver_base {
+  class receiver_2_t {
     using Sender = typename OpT::PredSender;
     using Receiver = typename OpT::Receiver;
 
     OpT& op_state_;
 
    public:
+    using receiver_concept = stdexec::receiver_t;
+
     template <stdexec::__one_of<ex::set_error_t, ex::set_stopped_t> _Tag, class... _Args>
     friend void tag_invoke(_Tag __tag, receiver_2_t&& __self, _Args&&... __args) noexcept {
       OpT& op_state = __self.op_state_;
@@ -231,12 +237,14 @@ namespace repeat_n_detail {
   };
 
   template <class OpT>
-  class receiver_1_t : public stdexec::__receiver_base {
+  class receiver_1_t {
     using Receiver = typename OpT::Receiver;
 
     OpT& op_state_;
 
    public:
+    using receiver_concept = stdexec::receiver_t;
+
     template <stdexec::__one_of<ex::set_error_t, ex::set_stopped_t> _Tag, class... _Args>
     friend void tag_invoke(_Tag __tag, receiver_1_t&& __self, _Args&&... __args) noexcept {
       OpT& op_state = __self.op_state_;

include/exec/__detail/__basic_sequence.hpp

@@ -31,7 +31,7 @@ namespace exec {
 
   template <class _ImplFn>
   struct __seqexpr<_ImplFn> {
-    using is_sender = sequence_tag;
+    using sender_concept = sequence_sender_t;
     using __t = __seqexpr;
     using __id = __seqexpr;
     using __tag_t = stdexec::__call_result_t<_ImplFn, stdexec::__cp, stdexec::__detail::__get_tag>;

include/exec/sequence/any_sequence_of.hpp

@@ -238,7 +238,7 @@ namespace exec {
         using __id = __sequence_sender;
         using completion_signatures = __compl_sigs;
         using item_types = exec::item_types<__item_sender>;
-        using is_sender = sequence_tag;
+        using sender_concept = sequence_sender_t;
 
         __t(const __t&) = delete;
         __t& operator=(const __t&) = delete;
@@ -337,7 +337,7 @@ namespace exec {
      public:
       using __id = any_sender;
       using __t = any_sender;
-      using is_sender = sequence_tag;
+      using sender_concept = sequence_sender_t;
       using completion_signatures = typename __sender_base::completion_signatures;
       using item_types = typename __sender_base::item_types;
 

include/exec/sequence/empty_sequence.hpp

@@ -40,7 +40,7 @@ namespace exec {
     struct __sender {
       struct __t {
         using __id = __sender;
-        using is_sender = sequence_tag;
+        using sender_concept = sequence_sender_t;
         using completion_signatures = stdexec::completion_signatures<stdexec::set_value_t()>;
         using item_types = exec::item_types<>;
 

include/exec/sequence_senders.hpp

@@ -19,7 +19,8 @@
 #include "../stdexec/execution.hpp"
 
 namespace exec {
-  struct sequence_tag { };
+  struct sequence_sender_t : stdexec::sender_t { };
+  using sequence_tag [[deprecated("Renamed to exec::sequence_sender_t")]] = exec::sequence_sender_t;
 
   namespace __sequence_sndr {
     using namespace stdexec;
@@ -117,9 +118,9 @@ namespace exec {
   } // namespace __sequence_sndr
 
   template <class _Sender>
-  concept __enable_sequence_sender =             //
-    requires { typename _Sender::is_sender; } && //
-    stdexec::same_as<typename _Sender::is_sender, sequence_tag>;
+  concept __enable_sequence_sender =                  //
+    requires { typename _Sender::sender_concept; } && //
+    stdexec::same_as<typename _Sender::sender_concept, sequence_tag>;
 
   template <class _Sender>
   inline constexpr bool enable_sequence_sender = __enable_sequence_sender<_Sender>;

include/exec/static_thread_pool.hpp

@@ -1279,7 +1279,7 @@ namespace exec {
      public:
       using __id = sequence;
 
-      using is_sender = sequence_tag;
+      using sender_concept = sequence_sender_t;
 
       using completion_signatures = stdexec::completion_signatures<
         stdexec::set_value_t(),

include/nvexec/stream/ensure_started.cuh

@@ -46,7 +46,7 @@ namespace nvexec::STDEXEC_STREAM_DETAIL_NS {
 
     template <class SenderId, class SharedState>
     struct receiver_t {
-      class __t : stream_receiver_base {
+      class __t : public stream_receiver_base {
         using Sender = stdexec::__t<SenderId>;
 
         __intrusive_ptr<SharedState> shared_state_;

include/nvexec/stream/then.cuh

@@ -39,7 +39,7 @@ namespace nvexec::STDEXEC_STREAM_DETAIL_NS {
     struct receiver_t {
       using Receiver = stdexec::__t<ReceiverId>;
 
-      class __t : stream_receiver_base {
+      class __t : public stream_receiver_base {
         Fun f_;
         operation_state_base_t<ReceiverId>& op_state_;
 

test/exec/sequence/test_ignore_all_values.cpp

@@ -83,7 +83,7 @@ namespace {
 
   template <class Item>
   struct sequence {
-    using is_sender = exec::sequence_tag;
+    using sender_concept = exec::sequence_sender_t;
 
     using completion_signatures =
       stdexec::completion_signatures<stdexec::set_value_t(), stdexec::set_error_t(int)>;

test/exec/test_sequence_senders.cpp

@@ -120,7 +120,7 @@ namespace {
 
   template <__completion_signature... _Sigs>
   struct some_sequence_sender_of {
-    using is_sender = sequence_tag;
+    using sender_concept = sequence_sender_t;
     using completion_signatures = stdexec::completion_signatures<set_value_t()>;
     using item_types = exec::item_types<some_sender_of<_Sigs...>>;