From 9fa3ce3fd6125404f17901cda878897016c33584 Mon Sep 17 00:00:00 2001
From: Afirez <707627402@qq.com>
Date: Sun, 14 Jun 2020 18:45:27 +0800
Subject: [PATCH] Add UdpSocket::PeerAddr #307

---
 src/net/udp/mod.rs | 26 ++++++++++++++++++++++++++
 tests/udp.rs       |  2 +-
 2 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/src/net/udp/mod.rs b/src/net/udp/mod.rs
index 30cceb7..18f6fc7 100644
--- a/src/net/udp/mod.rs
+++ b/src/net/udp/mod.rs
@@ -88,6 +88,32 @@ impl UdpSocket {
         }))
     }
 
+    /// Returns the peer address that this listener is connected to.
+    ///
+    /// This can be useful, for example, when connect to port 0 to figure out which port was
+    /// actually connected.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # fn main() -> std::io::Result<()> { async_std::task::block_on(async {
+    /// #
+    /// use async_std::net::UdpSocket;
+    ///
+    /// let socket1 = UdpSocket::bind("127.0.0.1:0").await?;
+    /// let socket2 = UdpSocket::bind("127.0.0.1:0").await?;
+    /// socket1.connect(socket2.local_addr()?).await?;
+    /// let addr = socket1.peer_addr()?;
+    /// #
+    /// # Ok(()) }) }
+    /// ```
+    pub fn peer_addr(&self) -> io::Result<SocketAddr> {
+        self.watcher
+            .get_ref()
+            .peer_addr()
+            .context(|| String::from("could not get peer address"))
+    }
+
     /// Returns the local address that this listener is bound to.
     ///
     /// This can be useful, for example, when binding to port 0 to figure out which port was
diff --git a/tests/udp.rs b/tests/udp.rs
index 15404f8..37024c4 100644
--- a/tests/udp.rs
+++ b/tests/udp.rs
@@ -19,7 +19,7 @@ fn send_recv() -> io::Result<()> {
 
         socket1.connect(socket2.local_addr()?).await?;
         socket2.connect(socket1.local_addr()?).await?;
-
+        assert_eq!(socket1.peer_addr()?, socket2.local_addr()?);
         socket1.send(THE_MERCHANT_OF_VENICE).await?;
 
         let mut buf = [0u8; 1024];