pub trait IntoFlow {
// Required method
fn into_flow(self) -> Flow;
}Expand description
What a plain callback may answer in place of a Flow.
A callback bound as FnMut(T) -> R with R: IntoFlow may return (), which keeps the source
going — so the common |value| { ... } needs no trailing Flow::Continue — or a Flow,
which lets it end its own stream. This is what
CallbackObserver relies on.
A callback that only diverges, such as |_| unreachable!(), is inferred to return !, which
no stable impl can cover: spell its return type out, as |_| -> () { unreachable!() }.
Required Methods§
Dyn Compatibility§
This trait is dyn compatible.
In older versions of Rust, dyn compatibility was called "object safety".