io: move into `tokio` crate (#1691)

A step towards collapsing Tokio sub crates into a single `tokio`
crate (#1318).

The `io` implementation is now provided by the main `tokio` crate.
Functionality can be opted out of by using the various net related
feature flags.

1 files changed, 37 insertions, 0 deletions

diff --git a/tokio/tests/io_read.rs b/tokio/tests/io_read.rs
new file mode 100644
index 00000000..01cd2fd6
--- /dev/null
+++ b/tokio/tests/io_read.rs
@@ -0,0 +1,37 @@
+#![warn(rust_2018_idioms)]
+
+use tokio::io::{AsyncRead, AsyncReadExt};
+use tokio_test::assert_ok;
+
+use std::io;
+use std::pin::Pin;
+use std::task::{Context, Poll};
+
+#[tokio::test]
+async fn read() {
+    #[derive(Default)]
+    struct Rd {
+        poll_cnt: usize,
+    }
+
+    impl AsyncRead for Rd {
+        fn poll_read(
+            mut self: Pin<&mut Self>,
+            _cx: &mut Context<'_>,
+            buf: &mut [u8],
+        ) -> Poll<io::Result<usize>> {
+            assert_eq!(0, self.poll_cnt);
+            self.poll_cnt += 1;
+
+            buf[0..11].copy_from_slice(b"hello world");
+            Poll::Ready(Ok(11))
+        }
+    }
+
+    let mut buf = Box::new([0; 11]);
+    let mut rd = Rd::default();
+
+    let n = assert_ok!(rd.read(&mut buf[..]).await);
+    assert_eq!(n, 11);
+    assert_eq!(buf[..], b"hello world"[..]);
+}