`inline_scheduler` doesn't advertise scheduler, cause spawn_future fail to compile with task

[lixin-wei]

according to exec.sched

For a given scheduler expression sch, the expression get_completion_scheduler<set_value_t>(get_env(schedule(sch))) shall compare equal to sch.

stdexec::inline_scheduler seems doesn't conform it.

which cause the following code fail to compile (compiler explorer):

ex::task<int> foo() { co_return 1; }

int main() {
  ex::simple_counting_scope scope;
  auto task = ex::inline_scheduler {}.schedule() | ex::let_value([foo = foo()]() mutable { return std::move(foo); });
  ex::spawn_future(std::move(task), scope.get_token());
}

I tried to add a query(get_completion_scheduler_t<set_value_t>) to it, but it broke a lot of tests. I wonder whether I understand it correctly?

[Cra3z]

The current implementation indeed deviates from the standard. This change was introduced in commit 6302fbe. For the rationale behind modifying inline_scheduler, please refer to: https://www.open-std.org/JTC1/SC22/WG21/docs/papers/2026/p3826r3.html#inline_scheduler-improvements

[lixin-wei]

@Cra3z I see, thanks for the explaination!
So the standard is still evolving? I thought it was already finalized on March.

[ericniebler]

that's true, the standard was finalized on march 28, but it takes time to update all the LaTeX sources of the c++ standard. the pr that will land this change is cplusplus/draft#8919, but it is still incomplete. and sometime after that, usually the next day, https://eel.is/c++draft/exec will reflect the changes.