Gate async socket behind feature

Author: evanrittenhouse

dgram/Cargo.toml

@@ -3,8 +3,11 @@ name = "dgram"
 version = "0.1.0"
 edition = "2021"
 
+[features]
+async = ["dep:tokio"]
+
 [dependencies]
 libc = "0.2.76"
 nix = "0.26.2"
 smallvec = { version = "1.10", features = ["union"] }
-tokio = { version = "1.29", features = ["full", "test-util"] }
+tokio = { version = "1.29", features = ["full", "test-util"], optional = true }

dgram/src/lib.rs

@@ -1,3 +1,4 @@
+#[cfg(feature = "async")]
 pub mod async_socket;
 pub mod socket;
 pub mod syscalls;