Type Alias SendFuture 

pub type SendFuture<'a, T> = Pin<Box<dyn Future<Output = T> + Send + 'a>>;

The future BridgePeer::send returns.

A type alias because the signature is long and appears three times — in the trait, in the Arc blanket impl, and in every implementor. Writing it out each time is where the two would drift apart, and a drift here is invisible until an adapter fails to satisfy the port.

Aliased Type

#[repr(transparent)]
pub struct SendFuture<'a, T> { /* private fields */ }