added async_scope_token

Author: dietmarkuehl

include/beman/execution/detail/async_scope_token.hpp

@@ -0,0 +1,43 @@
+// include/beman/execution/detail/async_scope_token.hpp               -*-C++-*-
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+#ifndef INCLUDED_INCLUDE_BEMAN_EXECUTION_DETAIL_ASYNC_SCOPE_TOKEN
+#define INCLUDED_INCLUDE_BEMAN_EXECUTION_DETAIL_ASYNC_SCOPE_TOKEN
+
+#include <beman/execution/detail/sender.hpp>
+#include <beman/execution/detail/sender_in.hpp>
+#include <beman/execution/detail/get_completion_signatures.hpp>
+#include <concepts>
+#include <type_traits>
+
+// ----------------------------------------------------------------------------
+
+namespace beman::execution::detail {
+    struct token_test_env {};
+
+    struct token_test_sender {
+        using sender_concept = ::beman::execution::sender_t;
+        auto get_completion_signatures(::beman::execution::detail::token_test_env) const noexcept {
+            return ::beman::execution::completion_signatures<>{};
+        }
+    };
+    static_assert(::beman::execution::sender<::beman::execution::detail::token_test_sender>);
+    static_assert(::beman::execution::sender_in<::beman::execution::detail::token_test_sender, ::beman::execution::detail::token_test_env>);
+}
+
+namespace beman::execution {
+    template <typename Token>
+    concept async_scope_token
+        = ::std::copyable<Token>
+        && requires(Token token) {
+            { token.try_associate() } -> ::std::same_as<bool>;
+            { token.disassociate() } noexcept;
+            { token.wrap(::std::declval<::beman::execution::detail::token_test_sender>()) }
+                -> ::beman::execution::sender_in<::beman::execution::detail::token_test_env>;
+        }
+        ;
+}
+
+// ----------------------------------------------------------------------------
+
+#endif

include/beman/execution/detail/nest.hpp

@@ -0,0 +1,23 @@
+// include/beman/execution/detail/nest.hpp                            -*-C++-*-
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+#ifndef INCLUDED_INCLUDE_BEMAN_EXECUTION_DETAIL_NEST
+#define INCLUDED_INCLUDE_BEMAN_EXECUTION_DETAIL_NEST
+
+#include <beman/execution/detail/async_scope_token.hpp>
+#include <beman/execution/detail/sender.hpp>
+
+// ----------------------------------------------------------------------------
+
+namespace beman::execution {
+    struct nest_t {
+        template <::beman::execution::sender Sender, ::beman::execution::async_scope_token Token>
+        auto operator()(Sender&&, Token&&) const {
+        }
+    };
+    inline constexpr nest_t nest{};
+}
+
+// ----------------------------------------------------------------------------
+
+#endif

tests/beman/execution/CMakeLists.txt

@@ -11,6 +11,8 @@ endif()
 list(
   APPEND
   execution_tests
+  exec-scope-concepts.test
+  exec-nest.test
   issue-144.test
   exec-on.test
   notify.test

tests/beman/execution/exec-nest.test.cpp

@@ -0,0 +1,25 @@
+// tests/beman/execution/exec-nest.test.cpp                           -*-C++-*-
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+#include <beman/execution/detail/nest.hpp>
+#include <test/execution.hpp>
+#include <concepts>
+
+// ----------------------------------------------------------------------------
+
+namespace {
+    struct sender {
+        using sender_concept = test_std::sender_t;
+    };
+    static_assert(test_std::sender<sender>);
+    static_assert(test_std::sender<sender&>);
+    static_assert(test_std::sender<sender const&>);
+}
+
+TEST(exec_nest) {
+    static_assert(std::same_as<test_std::nest_t const, decltype(test_std::nest)>);
+
+    sender sndr{};
+    int token{};
+    //test_std::nest(sndr, token);
+}

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

@@ -0,0 +1,65 @@
+// tests/beman/execution/exec-scope-concepts.test.cpp                 -*-C++-*-
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+#include <beman/execution/detail/async_scope_token.hpp>
+#include <beman/execution/detail/sender.hpp>
+#include <beman/execution/detail/sender_in.hpp>
+#include <beman/execution/detail/completion_signatures.hpp>
+#include <beman/execution/detail/set_value.hpp>
+#include <test/execution.hpp>
+#include <concepts>
+#include <utility>
+
+// ----------------------------------------------------------------------------
+
+namespace {
+    struct sender {
+        using sender_concept = test_std::sender_t;
+    };
+    static_assert(test_std::sender<sender>);
+
+    struct copyable {};
+    static_assert(std::copyable<copyable>);
+    struct non_copyable {
+        non_copyable() = default;
+        non_copyable(non_copyable const&) = delete;
+    };
+    static_assert(not std::copyable<non_copyable>);
+
+    struct empty {};
+
+    template <test_std::sender S>
+    struct wrap {
+        using sender_concept = test_std::sender_t;
+        std::remove_cvref_t<S> sndr;
+        template <typename E>
+        auto get_completion_signatures(E const& e) const noexcept {
+            return test_std::get_completion_signatures(sndr, e);
+        }
+    };
+    static_assert(test_std::sender<wrap<sender>>);
+
+    template <test_std::sender>
+    struct bad {
+        using sender_concept = test_std::sender_t;
+    };
+
+
+    template <typename Mem, typename Bool, bool Noexcept, template <test_std::sender> class Wrap>
+    struct token {
+        Mem mem{};
+        auto try_associate() -> Bool { return {}; }
+        auto disassociate() noexcept(Noexcept) -> void {}
+        template <test_std::sender Sender>
+        auto wrap(Sender&& sndr) -> Wrap<Sender> { return Wrap<Sender>(std::forward<Sender>(sndr)); }
+    };
+}
+
+TEST(exec_scope_concepts) {
+    static_assert(test_std::async_scope_token<token<copyable, bool, true, wrap>>);
+    static_assert(not test_std::async_scope_token<token<non_copyable, bool, true, wrap>>);
+    static_assert(not test_std::async_scope_token<token<copyable, int, true, wrap>>);
+    static_assert(not test_std::async_scope_token<token<copyable, bool, false, wrap>>);
+    static_assert(not test_std::async_scope_token<token<copyable, bool, true, bad>>);
+    static_assert(not test_std::async_scope_token<empty>);
+}