Greetings.

I'm looking at task.hpp here.

You're using coro::detail::promise::return_void() to rethrow the exception after the end of the coroutine. That part I understand.

But according to the spec, promise::return_void() is also called automatically during co_return. From the coroutine itself. Where a rethrow makes no sense.

This is a strange double use of the function, and I think it's just a bug. Or I don't get it, which is always a possibility.
In the case of promise-of-not-void you also use return_value() function for two purposes, but that works since they are distinct by parameter overload.

Best Regards, Jørn