1cfg_if::cfg_if! { 2 if #[cfg(feature = "std")] { 3 pub use std::sync::Arc; 4 } else { 5 pub use alloc::vec::Vec; 6 pub use alloc::boxed::Box; 7 pub use alloc::sync::Arc; 8 } 9} 10 11pub use waiter_trait::{Waiter, WaiterTime};