race_and_cancel

race_and_cancel is an operation that obtains senders using the given functors, starts all of them concurrently, and cancels the remaining ones when one finishes.

Note: race_and_cancel does not guarantee that only one sender completes without cancellation.

Prototype

template <typename... Functors>
sender race_and_cancel(Functors... fs);

Requirements

Every type of Functors is invocable with an argument of type async::cancellation_token and produces a sender.

Arguments

• fs - the functors to invoke to obtain the senders.

Return value

This function returns a sender of unspecified type. The sender does not return any value.

Examples

async::run(async::race_and_cancel(
	[] (async::cancellation_token) -> async::result<void> {
		std::cout << "Hi 1" << std::endl;
		co_return;
	},
	[] (async::cancellation_token) -> async::result<void> {
		std::cout << "Hi 2" << std::endl;
		co_return;
	}
));

Possible output:

Hi 1
Hi 2