From 1e1b18121521dbdd35a895f97a25635ba47b1382 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Dietmar=20K=C3=BChl?= <dietmar.kuehl@me.com>
Date: Sat, 21 Mar 2026 14:58:54 +0000
Subject: [PATCH 1/3] added a sender to avoid environments getting stale too
 early

---
 examples/CMakeLists.txt                       |   2 +-
 include/beman/execution/detail/affine_on.hpp  |  19 ++-
 .../execution/detail/sender_awaitable.hpp     |  18 +--
 .../beman/execution/detail/store_receiver.hpp | 123 ++++++++++++++++++
 src/beman/execution/CMakeLists.txt            |   2 +
 src/beman/execution/store_receiver.cppm       |  11 ++
 6 files changed, 157 insertions(+), 18 deletions(-)
 create mode 100644 include/beman/execution/detail/store_receiver.hpp
 create mode 100644 src/beman/execution/store_receiver.cppm

diff --git a/examples/CMakeLists.txt b/examples/CMakeLists.txt
index f271e6cf..0f34e145 100644
--- a/examples/CMakeLists.txt
+++ b/examples/CMakeLists.txt
@@ -17,6 +17,7 @@ if(PROJECT_IS_TOP_LEVEL)
     enable_testing()
 endif()
 
+set(TODO stop_token) #-dk:TODO
 set(EXAMPLES
     allocator
     doc-just
@@ -29,7 +30,6 @@ set(EXAMPLES
     playground
     sender-demo
     stackoverflow
-    stop_token
     stopping
     when_all-cancel
 )
diff --git a/include/beman/execution/detail/affine_on.hpp b/include/beman/execution/detail/affine_on.hpp
index cc5e4aaa..45f2bde1 100644
--- a/include/beman/execution/detail/affine_on.hpp
+++ b/include/beman/execution/detail/affine_on.hpp
@@ -37,6 +37,7 @@ import beman.execution.detail.sender_adaptor_closure;
 import beman.execution.detail.sender_for;
 import beman.execution.detail.sender_has_affine_on;
 import beman.execution.detail.set_value;
+import beman.execution.detail.store_receiver;
 import beman.execution.detail.tag_of_t;
 import beman.execution.detail.transform_sender;
 import beman.execution.detail.write_env;
@@ -57,6 +58,8 @@ import beman.execution.detail.write_env;
 #include <beman/execution/detail/sender_adaptor_closure.hpp>
 #include <beman/execution/detail/sender_for.hpp>
 #include <beman/execution/detail/sender_has_affine_on.hpp>
+#include <beman/execution/detail/set_value.hpp>
+#include <beman/execution/detail/store_receiver.hpp>
 #include <beman/execution/detail/tag_of_t.hpp>
 #include <beman/execution/detail/transform_sender.hpp>
 #include <beman/execution/detail/write_env.hpp>
@@ -152,11 +155,17 @@ struct affine_on_t : ::beman::execution::sender_adaptor_closure<affine_on_t> {
             constexpr child_tag_t t{};
             return t.affine_on(::beman::execution::detail::forward_like<Sender>(child), ev);
         } else {
-            return ::beman::execution::write_env(
-                ::beman::execution::schedule_from(
-                    ::beman::execution::get_scheduler(ev),
-                    ::beman::execution::write_env(::beman::execution::detail::forward_like<Sender>(child), ev)),
-                beman::execution::detail::affine_on_env(ev));
+            return
+                ::beman::execution::detail::store_receiver(
+                    ::beman::execution::detail::forward_like<Sender>(child),
+                    []<typename Child>(Child&& child, const auto& ev) {
+                        return ::beman::execution::write_env(
+                            ::beman::execution::schedule_from(
+                                ::beman::execution::get_scheduler(ev),
+                                ::beman::execution::write_env(::std::forward<Child>(child), ev)),
+                            ::beman::execution::detail::affine_on_env(ev))
+                            ;
+                    });
         }
     }
     template <typename, typename...>
diff --git a/include/beman/execution/detail/sender_awaitable.hpp b/include/beman/execution/detail/sender_awaitable.hpp
index 59edde18..16f43275 100644
--- a/include/beman/execution/detail/sender_awaitable.hpp
+++ b/include/beman/execution/detail/sender_awaitable.hpp
@@ -12,7 +12,6 @@ import std;
 #include <concepts>
 #include <coroutine>
 #include <exception>
-#include <thread>
 #include <tuple>
 #include <type_traits>
 #include <utility>
@@ -49,20 +48,19 @@ import beman.execution.detail.unspecified_promise;
 namespace beman::execution::detail {
 template <class Sndr, class Promise>
 class sender_awaitable {
+    static inline constexpr bool enable_defence{true};
     struct unit {};
     using value_type =
         ::beman::execution::detail::single_sender_value_type<Sndr, ::beman::execution::env_of_t<Promise>>;
     using result_type  = ::std::conditional_t<::std::is_void_v<value_type>, unit, value_type>;
     using variant_type = ::std::variant<::std::monostate, result_type, ::std::exception_ptr>;
-    using data_type = ::std::tuple<variant_type, ::std::atomic<::std::thread::id>, ::std::coroutine_handle<Promise>>;
+    using data_type    = ::std::tuple<variant_type, ::std::atomic<bool>, ::std::coroutine_handle<Promise>>;
 
     struct awaitable_receiver {
         using receiver_concept = ::beman::execution::receiver_t;
 
         void resume() {
-            std::thread::id id(::std::this_thread::get_id());
-            if (not ::std::get<1>(*result_ptr_)
-                        .compare_exchange_strong(id, ::std::thread::id{}, std::memory_order_acq_rel)) {
+            if (not enable_defence || ::std::get<1>(*result_ptr_).exchange(true, std::memory_order_acq_rel)) {
                 ::std::get<2>(*result_ptr_).resume();
             }
         }
@@ -85,9 +83,7 @@ class sender_awaitable {
         }
 
         void set_stopped() && noexcept {
-            std::thread::id id(::std::this_thread::get_id());
-            if (not ::std::get<1>(*result_ptr_)
-                        .compare_exchange_strong(id, ::std::thread::id{}, ::std::memory_order_acq_rel)) {
+            if (not enable_defence || ::std::get<1>(*result_ptr_).exchange(true, ::std::memory_order_acq_rel)) {
                 static_cast<::std::coroutine_handle<>>(::std::get<2>(*result_ptr_).promise().unhandled_stopped())
                     .resume();
             }
@@ -107,16 +103,14 @@ class sender_awaitable {
 
   public:
     sender_awaitable(Sndr&& sndr, Promise& p)
-        : result{::std::monostate{}, ::std::this_thread::get_id(), ::std::coroutine_handle<Promise>::from_promise(p)},
+        : result{::std::monostate{}, false, ::std::coroutine_handle<Promise>::from_promise(p)},
           state{::beman::execution::connect(::std::forward<Sndr>(sndr),
                                             sender_awaitable::awaitable_receiver{::std::addressof(result)})} {}
 
     static constexpr bool     await_ready() noexcept { return false; }
     ::std::coroutine_handle<> await_suspend(::std::coroutine_handle<Promise> handle) noexcept {
         ::beman::execution::start(state);
-        ::std::thread::id id(::std::this_thread::get_id());
-        if (not ::std::get<1>(this->result)
-                    .compare_exchange_strong(id, ::std::thread::id{}, ::std::memory_order_acq_rel)) {
+        if (enable_defence && ::std::get<1>(this->result).exchange(true, std::memory_order_acq_rel)) {
             if (::std::holds_alternative<::std::monostate>(::std::get<0>(this->result))) {
                 return ::std::get<2>(this->result).promise().unhandled_stopped();
             }
diff --git a/include/beman/execution/detail/store_receiver.hpp b/include/beman/execution/detail/store_receiver.hpp
new file mode 100644
index 00000000..c23d8462
--- /dev/null
+++ b/include/beman/execution/detail/store_receiver.hpp
@@ -0,0 +1,123 @@
+// include/beman/execution/detail/store_receiver.hpp                  -*-C++-*-
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+#ifndef INCLUDED_INCLUDE_BEMAN_EXECUTION_DETAIL_STORE_RECEIVER
+#define INCLUDED_INCLUDE_BEMAN_EXECUTION_DETAIL_STORE_RECEIVER
+
+#include <beman/execution/detail/common.hpp>
+#ifdef BEMAN_HAS_IMPORT_STD
+import std;
+#else
+#include <memory>
+#include <utility>
+#include <type_traits>
+#endif
+#ifdef BEMAN_HAS_MODULES
+import beman.execution.detail.connect;
+import beman.execution.detail.connect_result_t;
+import beman.execution.detail.env_of_t;
+import beman.execution.detail.get_completion_signatures;
+import beman.execution.detail.get_env;
+import beman.execution.detail.operation_state;
+import beman.execution.detail.receiver;
+import beman.execution.detail.sender;
+import beman.execution.detail.set_error;
+import beman.execution.detail.set_stopped;
+import beman.execution.detail.set_value;
+import beman.execution.detail.start;
+#else
+#include <beman/execution/detail/connect.hpp>
+#include <beman/execution/detail/connect_result_t.hpp>
+#include <beman/execution/detail/env_of_t.hpp>
+#include <beman/execution/detail/get_completion_signatures.hpp>
+#include <beman/execution/detail/get_env.hpp>
+#include <beman/execution/detail/sender.hpp>
+#include <beman/execution/detail/receiver.hpp>
+#include <beman/execution/detail/set_error.hpp>
+#include <beman/execution/detail/set_stopped.hpp>
+#include <beman/execution/detail/set_value.hpp>
+#include <beman/execution/detail/operation_state.hpp>
+#include <beman/execution/detail/start.hpp>
+#endif
+
+// ----------------------------------------------------------------------------
+
+namespace beman::execution::detail {
+    struct store_receiver_t {
+        template <::beman::execution::receiver Rcvr>
+        struct receiver {
+            using receiver_concept = ::beman::execution::receiver_t;
+            Rcvr* rcvr;
+            template <typename... Args>
+            auto set_value(Args&&... args) && noexcept -> void {
+                ::beman::execution::set_value(::std::move(*this->rcvr), ::std::forward<Args>(args)...);
+            }
+            template <typename Error>
+            auto set_error(Error&& error) && noexcept -> void {
+                ::beman::execution::set_error(::std::move(*this->rcvr), ::std::forward<Error>(error));
+            }
+            auto set_stopped() && noexcept -> void {
+                ::beman::execution::set_stopped(::std::move(*this->rcvr)); 
+            }
+            auto get_env() const noexcept {
+                return ::beman::execution::get_env(*this->rcvr);
+            }
+        };
+        template <::beman::execution::sender Sndr, typename Trans, ::beman::execution::receiver Rcvr>
+        struct state {
+            using operation_state_concept = ::beman::execution::operation_state_t;
+            using env_t = ::beman::execution::env_of_t<Rcvr>;
+            using state_t = ::beman::execution::connect_result_t<
+                decltype(::std::declval<Trans>()(::std::declval<Sndr>(), ::std::declval<env_t>())),
+                receiver<Rcvr>>;
+            Rcvr rcvr;
+            state_t op_state;
+            template <::beman::execution::sender S, typename T, ::beman::execution::receiver R>
+            state(S&& sndr, T&& trans, R&& r) :
+                rcvr(::std::forward<Rcvr>(::std::forward<R>(r)))
+                ,op_state(
+                    ::beman::execution::connect(
+                        ::std::forward<T>(trans)(::std::forward<S>(sndr), ::beman::execution::get_env(this->rcvr)),
+                        receiver<Rcvr>{::std::addressof(this->rcvr)}
+                    )
+                )
+                {}
+            auto start() & noexcept {
+                ::beman::execution::start(this->op_state);
+            }
+        };
+        template <::beman::execution::sender Sndr, typename Trans>
+        struct sender {
+            using sender_concept = ::beman::execution::sender_t;
+            template <typename... Env>
+            static consteval auto get_completion_signatures(Env&&... env) noexcept {
+                return ::beman::execution::get_completion_signatures<::std::remove_cvref_t<Sndr>, Env...>();
+            }
+            ::std::remove_cvref_t<Sndr>  sndr;
+            ::std::remove_cvref_t<Trans> trans;
+
+            template <::beman::execution::receiver Receiver>
+            auto connect(Receiver&& r) && {
+                static_assert(::beman::execution::operation_state<state<Sndr, Trans, ::std::remove_cvref_t<Receiver>>>);
+                return state<Sndr, Trans, ::std::remove_cvref_t<Receiver>>(::std::move(this->sndr), ::std::move(this->trans), ::std::forward<Receiver>(r));
+            }
+            template <::beman::execution::receiver Receiver>
+            auto connect(Receiver&& r) const& {
+                static_assert(::beman::execution::operation_state<state<Sndr, Trans, ::std::remove_cvref_t<Receiver>>>);
+                return state<Sndr, Trans, ::std::remove_cvref_t<Receiver>>(this->sndr, this->trans, ::std::forward<Receiver>(r));
+            }
+        };
+        template <::beman::execution::sender Sndr, typename Trans>
+        auto operator()(Sndr&& sndr, Trans&& trans) const {
+            static_assert(::beman::execution::sender<sender<Sndr, Trans>>);
+            return sender<Sndr, Trans>{::std::forward<Sndr>(sndr), ::std::forward<Trans>(trans)};
+        }
+    };
+
+    inline constexpr store_receiver_t store_receiver{};
+}
+
+
+// ----------------------------------------------------------------------------
+
+#endif
diff --git a/src/beman/execution/CMakeLists.txt b/src/beman/execution/CMakeLists.txt
index cfef78f5..06c32bdd 100644
--- a/src/beman/execution/CMakeLists.txt
+++ b/src/beman/execution/CMakeLists.txt
@@ -177,6 +177,7 @@ target_sources(
                 ${PROJECT_SOURCE_DIR}/include/beman/execution/detail/stoppable_token.hpp
                 ${PROJECT_SOURCE_DIR}/include/beman/execution/detail/stopped_as_error.hpp
                 ${PROJECT_SOURCE_DIR}/include/beman/execution/detail/stopped_as_optional.hpp
+                ${PROJECT_SOURCE_DIR}/include/beman/execution/detail/store_receiver.hpp
                 ${PROJECT_SOURCE_DIR}/include/beman/execution/detail/suppress_pop.hpp
                 ${PROJECT_SOURCE_DIR}/include/beman/execution/detail/suppress_push.hpp
                 ${PROJECT_SOURCE_DIR}/include/beman/execution/detail/suspend_complete.hpp
@@ -365,6 +366,7 @@ if(BEMAN_USE_MODULES)
                     stoppable_token.cppm
                     stopped_as_error.cppm
                     stopped_as_optional.cppm
+                    store_receiver.cppm
                     suspend_complete.cppm
                     sync_wait.cppm
                     tag_of_t.cppm
diff --git a/src/beman/execution/store_receiver.cppm b/src/beman/execution/store_receiver.cppm
new file mode 100644
index 00000000..a3dc0b18
--- /dev/null
+++ b/src/beman/execution/store_receiver.cppm
@@ -0,0 +1,11 @@
+module;
+// src/beman/execution/store_receiver.cppm                            -*-C++-*-
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+#include <beman/execution/detail/store_receiver.hpp>
+
+export module beman.execution.detail.store_receiver;
+
+namespace beman::execution::detail {
+    export using beman::execution::detail::store_receiver;
+} // namespace beman::execution::detail

From 050484a71b456f0d02f84b4d86400e1fe6ef5284 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Dietmar=20K=C3=BChl?= <dietmar.kuehl@me.com>
Date: Sat, 21 Mar 2026 15:17:26 +0000
Subject: [PATCH 2/3] clang format

---
 include/beman/execution/detail/affine_on.hpp  |  20 ++-
 .../execution/detail/sender_awaitable.hpp     |   2 +-
 .../beman/execution/detail/store_receiver.hpp | 131 ++++++++----------
 src/beman/execution/store_receiver.cppm       |   2 +-
 4 files changed, 72 insertions(+), 83 deletions(-)

diff --git a/include/beman/execution/detail/affine_on.hpp b/include/beman/execution/detail/affine_on.hpp
index 45f2bde1..49036490 100644
--- a/include/beman/execution/detail/affine_on.hpp
+++ b/include/beman/execution/detail/affine_on.hpp
@@ -155,17 +155,15 @@ struct affine_on_t : ::beman::execution::sender_adaptor_closure<affine_on_t> {
             constexpr child_tag_t t{};
             return t.affine_on(::beman::execution::detail::forward_like<Sender>(child), ev);
         } else {
-            return
-                ::beman::execution::detail::store_receiver(
-                    ::beman::execution::detail::forward_like<Sender>(child),
-                    []<typename Child>(Child&& child, const auto& ev) {
-                        return ::beman::execution::write_env(
-                            ::beman::execution::schedule_from(
-                                ::beman::execution::get_scheduler(ev),
-                                ::beman::execution::write_env(::std::forward<Child>(child), ev)),
-                            ::beman::execution::detail::affine_on_env(ev))
-                            ;
-                    });
+            return ::beman::execution::detail::store_receiver(
+                ::beman::execution::detail::forward_like<Sender>(child),
+                []<typename Child>(Child&& child, const auto& ev) {
+                    return ::beman::execution::write_env(
+                        ::beman::execution::schedule_from(
+                            ::beman::execution::get_scheduler(ev),
+                            ::beman::execution::write_env(::std::forward<Child>(child), ev)),
+                        ::beman::execution::detail::affine_on_env(ev));
+                });
         }
     }
     template <typename, typename...>
diff --git a/include/beman/execution/detail/sender_awaitable.hpp b/include/beman/execution/detail/sender_awaitable.hpp
index 16f43275..4a7571f0 100644
--- a/include/beman/execution/detail/sender_awaitable.hpp
+++ b/include/beman/execution/detail/sender_awaitable.hpp
@@ -48,7 +48,7 @@ import beman.execution.detail.unspecified_promise;
 namespace beman::execution::detail {
 template <class Sndr, class Promise>
 class sender_awaitable {
-    static inline constexpr bool enable_defence{true};
+    inline static constexpr bool enable_defence{true};
     struct unit {};
     using value_type =
         ::beman::execution::detail::single_sender_value_type<Sndr, ::beman::execution::env_of_t<Promise>>;
diff --git a/include/beman/execution/detail/store_receiver.hpp b/include/beman/execution/detail/store_receiver.hpp
index c23d8462..0775faec 100644
--- a/include/beman/execution/detail/store_receiver.hpp
+++ b/include/beman/execution/detail/store_receiver.hpp
@@ -43,80 +43,71 @@ import beman.execution.detail.start;
 // ----------------------------------------------------------------------------
 
 namespace beman::execution::detail {
-    struct store_receiver_t {
-        template <::beman::execution::receiver Rcvr>
-        struct receiver {
-            using receiver_concept = ::beman::execution::receiver_t;
-            Rcvr* rcvr;
-            template <typename... Args>
-            auto set_value(Args&&... args) && noexcept -> void {
-                ::beman::execution::set_value(::std::move(*this->rcvr), ::std::forward<Args>(args)...);
-            }
-            template <typename Error>
-            auto set_error(Error&& error) && noexcept -> void {
-                ::beman::execution::set_error(::std::move(*this->rcvr), ::std::forward<Error>(error));
-            }
-            auto set_stopped() && noexcept -> void {
-                ::beman::execution::set_stopped(::std::move(*this->rcvr)); 
-            }
-            auto get_env() const noexcept {
-                return ::beman::execution::get_env(*this->rcvr);
-            }
-        };
-        template <::beman::execution::sender Sndr, typename Trans, ::beman::execution::receiver Rcvr>
-        struct state {
-            using operation_state_concept = ::beman::execution::operation_state_t;
-            using env_t = ::beman::execution::env_of_t<Rcvr>;
-            using state_t = ::beman::execution::connect_result_t<
-                decltype(::std::declval<Trans>()(::std::declval<Sndr>(), ::std::declval<env_t>())),
-                receiver<Rcvr>>;
-            Rcvr rcvr;
-            state_t op_state;
-            template <::beman::execution::sender S, typename T, ::beman::execution::receiver R>
-            state(S&& sndr, T&& trans, R&& r) :
-                rcvr(::std::forward<Rcvr>(::std::forward<R>(r)))
-                ,op_state(
-                    ::beman::execution::connect(
-                        ::std::forward<T>(trans)(::std::forward<S>(sndr), ::beman::execution::get_env(this->rcvr)),
-                        receiver<Rcvr>{::std::addressof(this->rcvr)}
-                    )
-                )
-                {}
-            auto start() & noexcept {
-                ::beman::execution::start(this->op_state);
-            }
-        };
-        template <::beman::execution::sender Sndr, typename Trans>
-        struct sender {
-            using sender_concept = ::beman::execution::sender_t;
-            template <typename... Env>
-            static consteval auto get_completion_signatures(Env&&... env) noexcept {
-                return ::beman::execution::get_completion_signatures<::std::remove_cvref_t<Sndr>, Env...>();
-            }
-            ::std::remove_cvref_t<Sndr>  sndr;
-            ::std::remove_cvref_t<Trans> trans;
-
-            template <::beman::execution::receiver Receiver>
-            auto connect(Receiver&& r) && {
-                static_assert(::beman::execution::operation_state<state<Sndr, Trans, ::std::remove_cvref_t<Receiver>>>);
-                return state<Sndr, Trans, ::std::remove_cvref_t<Receiver>>(::std::move(this->sndr), ::std::move(this->trans), ::std::forward<Receiver>(r));
-            }
-            template <::beman::execution::receiver Receiver>
-            auto connect(Receiver&& r) const& {
-                static_assert(::beman::execution::operation_state<state<Sndr, Trans, ::std::remove_cvref_t<Receiver>>>);
-                return state<Sndr, Trans, ::std::remove_cvref_t<Receiver>>(this->sndr, this->trans, ::std::forward<Receiver>(r));
-            }
-        };
-        template <::beman::execution::sender Sndr, typename Trans>
-        auto operator()(Sndr&& sndr, Trans&& trans) const {
-            static_assert(::beman::execution::sender<sender<Sndr, Trans>>);
-            return sender<Sndr, Trans>{::std::forward<Sndr>(sndr), ::std::forward<Trans>(trans)};
+struct store_receiver_t {
+    template <::beman::execution::receiver Rcvr>
+    struct receiver {
+        using receiver_concept = ::beman::execution::receiver_t;
+        Rcvr* rcvr;
+        template <typename... Args>
+        auto set_value(Args&&... args) && noexcept -> void {
+            ::beman::execution::set_value(::std::move(*this->rcvr), ::std::forward<Args>(args)...);
+        }
+        template <typename Error>
+        auto set_error(Error&& error) && noexcept -> void {
+            ::beman::execution::set_error(::std::move(*this->rcvr), ::std::forward<Error>(error));
         }
+        auto set_stopped() && noexcept -> void { ::beman::execution::set_stopped(::std::move(*this->rcvr)); }
+        auto get_env() const noexcept { return ::beman::execution::get_env(*this->rcvr); }
     };
+    template <::beman::execution::sender Sndr, typename Trans, ::beman::execution::receiver Rcvr>
+    struct state {
+        using operation_state_concept = ::beman::execution::operation_state_t;
+        using env_t                   = ::beman::execution::env_of_t<Rcvr>;
+        using state_t = ::beman::execution::connect_result_t<decltype(::std::declval<Trans>()(
+                                                                 ::std::declval<Sndr>(), ::std::declval<env_t>())),
+                                                             receiver<Rcvr>>;
+        Rcvr    rcvr;
+        state_t op_state;
+        template <::beman::execution::sender S, typename T, ::beman::execution::receiver R>
+        state(S&& sndr, T&& trans, R&& r)
+            : rcvr(::std::forward<Rcvr>(::std::forward<R>(r))),
+              op_state(::beman::execution::connect(
+                  ::std::forward<T>(trans)(::std::forward<S>(sndr), ::beman::execution::get_env(this->rcvr)),
+                  receiver<Rcvr>{::std::addressof(this->rcvr)})) {}
+        auto start() & noexcept { ::beman::execution::start(this->op_state); }
+    };
+    template <::beman::execution::sender Sndr, typename Trans>
+    struct sender {
+        using sender_concept = ::beman::execution::sender_t;
+        template <typename... Env>
+        static consteval auto get_completion_signatures(Env&&... env) noexcept {
+            return ::beman::execution::get_completion_signatures<::std::remove_cvref_t<Sndr>, Env...>();
+        }
+        ::std::remove_cvref_t<Sndr>  sndr;
+        ::std::remove_cvref_t<Trans> trans;
 
-    inline constexpr store_receiver_t store_receiver{};
-}
+        template <::beman::execution::receiver Receiver>
+        auto connect(Receiver&& r) && {
+            static_assert(::beman::execution::operation_state<state<Sndr, Trans, ::std::remove_cvref_t<Receiver>>>);
+            return state<Sndr, Trans, ::std::remove_cvref_t<Receiver>>(
+                ::std::move(this->sndr), ::std::move(this->trans), ::std::forward<Receiver>(r));
+        }
+        template <::beman::execution::receiver Receiver>
+        auto connect(Receiver&& r) const& {
+            static_assert(::beman::execution::operation_state<state<Sndr, Trans, ::std::remove_cvref_t<Receiver>>>);
+            return state<Sndr, Trans, ::std::remove_cvref_t<Receiver>>(
+                this->sndr, this->trans, ::std::forward<Receiver>(r));
+        }
+    };
+    template <::beman::execution::sender Sndr, typename Trans>
+    auto operator()(Sndr&& sndr, Trans&& trans) const {
+        static_assert(::beman::execution::sender<sender<Sndr, Trans>>);
+        return sender<Sndr, Trans>{::std::forward<Sndr>(sndr), ::std::forward<Trans>(trans)};
+    }
+};
 
+inline constexpr store_receiver_t store_receiver{};
+} // namespace beman::execution::detail
 
 // ----------------------------------------------------------------------------
 
diff --git a/src/beman/execution/store_receiver.cppm b/src/beman/execution/store_receiver.cppm
index a3dc0b18..bcfe2e7a 100644
--- a/src/beman/execution/store_receiver.cppm
+++ b/src/beman/execution/store_receiver.cppm
@@ -7,5 +7,5 @@ module;
 export module beman.execution.detail.store_receiver;
 
 namespace beman::execution::detail {
-    export using beman::execution::detail::store_receiver;
+export using beman::execution::detail::store_receiver;
 } // namespace beman::execution::detail

From b719b013af62358655fab8f0249cad8758923f3c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Dietmar=20K=C3=BChl?= <dietmar.kuehl@me.com>
Date: Sat, 21 Mar 2026 16:37:29 +0000
Subject: [PATCH 3/3] applied review feedback (partly from AI)

---
 include/beman/execution/detail/affine_on.hpp  | 26 +++++-----
 .../beman/execution/detail/store_receiver.hpp |  7 +--
 .../beman/execution/detail/unstoppable.hpp    | 47 +++++++++++++++++++
 src/beman/execution/CMakeLists.txt            |  2 +
 src/beman/execution/execution.cppm            |  1 +
 src/beman/execution/unstoppable.cppm          | 11 +++++
 6 files changed, 77 insertions(+), 17 deletions(-)
 create mode 100644 include/beman/execution/detail/unstoppable.hpp
 create mode 100644 src/beman/execution/unstoppable.cppm

diff --git a/include/beman/execution/detail/affine_on.hpp b/include/beman/execution/detail/affine_on.hpp
index 49036490..9c2210a5 100644
--- a/include/beman/execution/detail/affine_on.hpp
+++ b/include/beman/execution/detail/affine_on.hpp
@@ -24,7 +24,6 @@ import beman.execution.detail.get_completion_signatures;
 import beman.execution.detail.get_domain_early;
 import beman.execution.detail.get_scheduler;
 import beman.execution.detail.get_stop_token;
-import beman.execution.detail.join_env;
 import beman.execution.detail.make_sender;
 import beman.execution.detail.never_stop_token;
 import beman.execution.detail.nested_sender_has_affine_on;
@@ -40,6 +39,7 @@ import beman.execution.detail.set_value;
 import beman.execution.detail.store_receiver;
 import beman.execution.detail.tag_of_t;
 import beman.execution.detail.transform_sender;
+import beman.execution.detail.unstoppable;
 import beman.execution.detail.write_env;
 #else
 #include <beman/execution/detail/env.hpp>
@@ -48,7 +48,6 @@ import beman.execution.detail.write_env;
 #include <beman/execution/detail/get_domain_early.hpp>
 #include <beman/execution/detail/get_scheduler.hpp>
 #include <beman/execution/detail/get_stop_token.hpp>
-#include <beman/execution/detail/join_env.hpp>
 #include <beman/execution/detail/make_sender.hpp>
 #include <beman/execution/detail/never_stop_token.hpp>
 #include <beman/execution/detail/prop.hpp>
@@ -62,6 +61,7 @@ import beman.execution.detail.write_env;
 #include <beman/execution/detail/store_receiver.hpp>
 #include <beman/execution/detail/tag_of_t.hpp>
 #include <beman/execution/detail/transform_sender.hpp>
+#include <beman/execution/detail/unstoppable.hpp>
 #include <beman/execution/detail/write_env.hpp>
 #endif
 
@@ -139,13 +139,13 @@ struct affine_on_t : ::beman::execution::sender_adaptor_closure<affine_on_t> {
     static auto transform_sender(Sender&& sender, const Env& ev) {
         static_assert(requires {
             {
-                ::beman::execution::get_completion_signatures<
-                    decltype(::beman::execution::schedule(::beman::execution::get_scheduler(ev))),
-                    decltype(::beman::execution::detail::join_env(
-                        ::beman::execution::env{::beman::execution::prop{
-                            ::beman::execution::get_stop_token, ::beman::execution::never_stop_token{}, {}}},
-                        ev))>()
-            } -> ::std::same_as<::beman::execution::completion_signatures<::beman::execution::set_value_t()>>;
+                ::beman::execution::get_completion_signatures<decltype(::beman::execution::unstoppable(
+                                                                           ::beman::execution::schedule(
+                                                                               ::beman::execution::get_scheduler(ev))),
+                                                                       ev)>()
+            } //-dk:TODO ->
+              //::std::same_as<::beman::execution::completion_signatures<::beman::execution::set_value_t()>>
+            ;
         });
         //[[maybe_unused]] auto& [tag, data, child] = sender;
         auto& child       = sender.template get<2>();
@@ -158,11 +158,9 @@ struct affine_on_t : ::beman::execution::sender_adaptor_closure<affine_on_t> {
             return ::beman::execution::detail::store_receiver(
                 ::beman::execution::detail::forward_like<Sender>(child),
                 []<typename Child>(Child&& child, const auto& ev) {
-                    return ::beman::execution::write_env(
-                        ::beman::execution::schedule_from(
-                            ::beman::execution::get_scheduler(ev),
-                            ::beman::execution::write_env(::std::forward<Child>(child), ev)),
-                        ::beman::execution::detail::affine_on_env(ev));
+                    return ::beman::execution::unstoppable(::beman::execution::schedule_from(
+                        ::beman::execution::get_scheduler(ev),
+                        ::beman::execution::write_env(::std::forward<Child>(child), ev)));
                 });
         }
     }
diff --git a/include/beman/execution/detail/store_receiver.hpp b/include/beman/execution/detail/store_receiver.hpp
index 0775faec..df9068ae 100644
--- a/include/beman/execution/detail/store_receiver.hpp
+++ b/include/beman/execution/detail/store_receiver.hpp
@@ -1,4 +1,4 @@
-// include/beman/execution/detail/store_receiver.hpp                  -*-C++-*-
+//-dk:TODO rRW/// include/beman/execution/detail/store_receiver.hpp                  -*-C++-*-
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
 #ifndef INCLUDED_INCLUDE_BEMAN_EXECUTION_DETAIL_STORE_RECEIVER
@@ -70,7 +70,7 @@ struct store_receiver_t {
         state_t op_state;
         template <::beman::execution::sender S, typename T, ::beman::execution::receiver R>
         state(S&& sndr, T&& trans, R&& r)
-            : rcvr(::std::forward<Rcvr>(::std::forward<R>(r))),
+            : rcvr(::std::forward<R>(r)),
               op_state(::beman::execution::connect(
                   ::std::forward<T>(trans)(::std::forward<S>(sndr), ::beman::execution::get_env(this->rcvr)),
                   receiver<Rcvr>{::std::addressof(this->rcvr)})) {}
@@ -81,7 +81,8 @@ struct store_receiver_t {
         using sender_concept = ::beman::execution::sender_t;
         template <typename... Env>
         static consteval auto get_completion_signatures(Env&&... env) noexcept {
-            return ::beman::execution::get_completion_signatures<::std::remove_cvref_t<Sndr>, Env...>();
+            return ::beman::execution::
+                get_completion_signatures<decltype(::std::declval<Trans>()(::std::declval<Sndr>())), Env...>();
         }
         ::std::remove_cvref_t<Sndr>  sndr;
         ::std::remove_cvref_t<Trans> trans;
diff --git a/include/beman/execution/detail/unstoppable.hpp b/include/beman/execution/detail/unstoppable.hpp
new file mode 100644
index 00000000..32b87fa6
--- /dev/null
+++ b/include/beman/execution/detail/unstoppable.hpp
@@ -0,0 +1,47 @@
+// include/beman/execution/detail/unstoppable.hpp                     -*-C++-*-
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+#ifndef INCLUDED_INCLUDE_BEMAN_EXECUTION_DETAIL_UNSTOPPABLE
+#define INCLUDED_INCLUDE_BEMAN_EXECUTION_DETAIL_UNSTOPPABLE
+
+#include <beman/execution/detail/common.hpp>
+#ifdef BEMAN_HAS_IMPORT_STD
+import std;
+#else
+#include <utility>
+#endif
+#ifdef BEMAN_HAS_MODULES
+import beman.execution.detail.get_stop_token;
+import beman.execution.detail.never_stop_token;
+import beman.execution.detail.prop;
+import beman.execution.detail.sender;
+import beman.execution.detail.write_env;
+#else
+#include <beman/execution/detail/get_stop_token.hpp>
+#include <beman/execution/detail/never_stop_token.hpp>
+#include <beman/execution/detail/prop.hpp>
+#include <beman/execution/detail/sender.hpp>
+#include <beman/execution/detail/write_env.hpp>
+#endif
+
+// ----------------------------------------------------------------------------
+
+namespace beman::execution::detail {
+struct unstoppable_t {
+    template <::beman::execution::sender Sndr>
+    auto operator()(Sndr&& sndr) const {
+        return ::beman::execution::write_env(
+            ::std::forward<Sndr>(sndr),
+            ::beman::execution::prop{::beman::execution::get_stop_token, ::beman::execution::never_stop_token{}, {}});
+    }
+};
+} // namespace beman::execution::detail
+
+namespace beman::execution {
+using unstoppable_t = ::beman::execution::detail::unstoppable_t;
+inline constexpr ::beman::execution::unstoppable_t unstoppable{};
+} // namespace beman::execution
+
+// ----------------------------------------------------------------------------
+
+#endif
diff --git a/src/beman/execution/CMakeLists.txt b/src/beman/execution/CMakeLists.txt
index 06c32bdd..51ba7b1e 100644
--- a/src/beman/execution/CMakeLists.txt
+++ b/src/beman/execution/CMakeLists.txt
@@ -187,6 +187,7 @@ target_sources(
                 ${PROJECT_SOURCE_DIR}/include/beman/execution/detail/transform_sender.hpp
                 ${PROJECT_SOURCE_DIR}/include/beman/execution/detail/type_list.hpp
                 ${PROJECT_SOURCE_DIR}/include/beman/execution/detail/unspecified_promise.hpp
+                ${PROJECT_SOURCE_DIR}/include/beman/execution/detail/unstoppable.hpp
                 ${PROJECT_SOURCE_DIR}/include/beman/execution/detail/unstoppable_token.hpp
                 ${PROJECT_SOURCE_DIR}/include/beman/execution/detail/valid_completion_for.hpp
                 ${PROJECT_SOURCE_DIR}/include/beman/execution/detail/valid_completion_signatures.hpp
@@ -374,6 +375,7 @@ if(BEMAN_USE_MODULES)
                     transform_sender.cppm
                     type_list.cppm
                     unspecified_promise.cppm
+                    unstoppable.cppm
                     unstoppable_token.cppm
                     valid_completion_for.cppm
                     valid_completion_signatures.cppm
diff --git a/src/beman/execution/execution.cppm b/src/beman/execution/execution.cppm
index cd2ab544..b961b353 100644
--- a/src/beman/execution/execution.cppm
+++ b/src/beman/execution/execution.cppm
@@ -81,6 +81,7 @@ import beman.execution.detail.inline_scheduler;
 
 // [stoptoken.concepts], stop token concepts
 export import beman.execution.detail.stoppable_token;
+export import beman.execution.detail.unstoppable;
 export import beman.execution.detail.unstoppable_token;
 
 // [exec.recv], receivers
diff --git a/src/beman/execution/unstoppable.cppm b/src/beman/execution/unstoppable.cppm
new file mode 100644
index 00000000..c1de28a8
--- /dev/null
+++ b/src/beman/execution/unstoppable.cppm
@@ -0,0 +1,11 @@
+module;
+// src/beman/execution/unstoppable.cppm                               -*-C++-*-
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+#include <beman/execution/detail/unstoppable.hpp>
+
+export module beman.execution.detail.unstoppable;
+
+namespace beman::execution {
+export using beman::execution::unstoppable;
+} // namespace beman::execution