async: Don't pull all of the futures crates

Author: bilelmoussaoui

Cargo.toml

@@ -24,7 +24,7 @@ include = [
 [features]
 default = ["std", "async"]
 std = []
-async = ["futures"]
+async = ["futures-io", "futures-util"]
 
 [dev-dependencies]
 async-std = { version = "1.9.0", features = ["attributes"] }
@@ -77,4 +77,5 @@ travis-ci = { repository = "Geal/cookie-factory" }
 maintenance = { status = "actively-developed" }
 
 [dependencies]
-futures = { version = "0.3.16", optional = true }
+futures-io = { version = "0.3.30", optional = true }
+futures-util = { version = "0.3.30", optional = true, features = ["io"]}

src/async_bufwriter.rs

@@ -1,4 +1,5 @@
-use futures::io::{AsyncWrite, AsyncWriteExt};
+use futures_io::AsyncWrite;
+use futures_util::io::AsyncWriteExt;
 
 pub struct AsyncBufWriter<W: AsyncWrite + Unpin> {
     inner: W,