Hi Everyone.
I am very uneasy about the dummy co_retuned value that I see in the
examples of async::generator. Like the one in the echo server example:
https://klemens.dev/async/tutorial.html#echo_server
async::generator listen()
{
tcp_acceptor acceptor({co_await async::this_coro::executor}, {tcp::v4(),
55555});
for (;;)
{
tcp_socket sock = co_await acceptor.async_accept();
co_yield std::move(sock);
}
co_return tcp_socket{acceptor.get_executor()}; // :-(
}
The control will never get to the co_return. The caller never even tries to
observe this value. and yet we are forced to return it.
Interestingly, the coroutine example from ASIO doesn't have this due to a
different design:
https://www.boost.org/doc/libs/1_83_0/doc/html/boost_asio/example/cpp20/coro...
std::generator doesn't have this.
In other examples the degenerate value is used to indicate the end of
generation.
I do not know the coroutines to be able to tell if this is a design problem
with async::generator or with C++ coroutines in general. But it feels wrong
that the end of generation should be signaled in this way.
Regards,
&rzej;
