Type Alias BoxSyncFuture 

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

Helper type: Like BoxFuture, but also requires that the future be Sync.

Aliased Type

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