Feature request: `Sender::send_with`

[Lucretiel]

In a library I'm working on, I collect a series of one shot Senders and send clones of a final result value to each of them. I'd obviously like to avoid cloning if unnecessary, when the Receiver had been closed or dropped. I'd therefore like to request a method with this signature:

fn send_with(self, value: impl FnOnce() -> T) -> Result<(), ()>

Where the value function is only called if a receiver is listening.