keep std::sync::Arc

Cargo.toml

@@ -48,7 +48,6 @@ std = [
   "once_cell",
   "pin-utils",
   "slab",
-  "piper",
 ]
 alloc = [
   "futures-core/alloc",
@@ -77,7 +76,6 @@ pin-project-lite = { version = "0.1.4", optional = true }
 pin-utils = { version = "0.1.0-alpha.4", optional = true }
 slab = { version = "0.4.2", optional = true }
 smol = { path = "../smol", optional = true }
-piper = { git = "https://github.com/stjepang/piper.git", branch = "master", optional = true }
 
 [dev-dependencies]
 femme = "1.3.0"

src/sync/mod.rs

@@ -174,10 +174,7 @@
 #![allow(clippy::needless_doctest_main)]
 
 #[doc(inline)]
-pub use std::sync::Weak;
+pub use std::sync::{Arc, Weak};
-
-#[doc(inline)]
-pub use piper::Arc;
 
 pub use mutex::{Mutex, MutexGuard};
 pub use rwlock::{RwLock, RwLockReadGuard, RwLockWriteGuard};