Merge #5846

5846: [execution] Add schedule_result_t alias template. r=hkaiser a=SAtacker

- Alias schedule_result_t gives the result type of schedule

Signed-off-by: Shreyas Atre <shreyasatre16@gmail.com>


## Any background context you want to provide?

- #5045 (comment)
- [X] I have added a new feature and have added tests to go along with it.
- [ ] I have fixed a bug and have added a regression test.
- [ ] I have added a test using random numbers; I have made sure it uses a seed, and that the random numbers generated are valid inputs for the tests.


Co-authored-by: Shreyas Atre <shreyasatre16@gmail.com>

libs/core/execution_base/include/hpx/execution_base/sender.hpp

@@ -179,6 +179,9 @@ namespace hpx { namespace execution { namespace experimental {
     template <typename Scheduler>
     inline constexpr bool is_scheduler_v = is_scheduler<Scheduler>::value;
 
+    template <typename S>
+    using schedule_result_t = hpx::util::invoke_result_t<schedule_t, S>;
+
     template <typename S, typename R>
     using connect_result_t = hpx::util::invoke_result_t<connect_t, S, R>;
 }}}    // namespace hpx::execution::experimental

libs/core/execution_base/tests/unit/basic_schedule.cpp

@@ -122,5 +122,16 @@ int main()
     HPX_TEST_EQ(friend_tag_invoke_schedule_calls, std::size_t(1));
     HPX_TEST_EQ(tag_invoke_schedule_calls, std::size_t(1));
 
+    static_assert(
+        std::is_same_v<
+            hpx::execution::experimental::schedule_result_t<scheduler_1>,
+            sender>,
+        "Result of scheduler is a sender");
+    static_assert(
+        std::is_same_v<
+            hpx::execution::experimental::schedule_result_t<scheduler_2>,
+            sender>,
+        "Result of scheduler is a sender");
+
     return hpx::util::report_errors();
 }