let

let is an operation that obtains a value using the given functor, stores it in a variable, and obtains a sender to start using the second functor, passing a reference to the variable as an argument.

Prototype

template <typename Pred, typename Func>
sender let(Pred pred, Func func);

Requirements

Pred is a functor that returns a value. Func is a functor that returns a sender and accepts a reference to the value returned by Pred as an argument.

Arguments

pred - the functor to execute to obtain the value.
func - the function to call to obtain the sender.

Return value

This function returns a sender of unspecified type. The sender returns the value returned by the obtained sender.

Examples

std::cout << async::run(async::let([] { return 3; },
			[] (int &i) -> async::result<int> {
				return i * 2;
			})) << std::endl;

Output: