Add bytes() method to MutByteBuf to allow reading of data already written

without necessitating flipping to ByteBuf.

src/buf/byte.rs

@@ -303,6 +303,10 @@ impl MutByteBuf {
             len as usize
         }
     }
+
+    pub fn bytes<'a>(&'a self) -> &'a [u8] {
+        &self.buf.mem.bytes()[..self.buf.pos()]
+    }
 }
 
 impl MutBuf for MutByteBuf {

test/test_byte_buf.rs

@@ -17,6 +17,18 @@ pub fn test_initial_buf_empty() {
     assert!(buf.remaining() == 128);
 }
 
+#[test]
+pub fn test_byte_buf_bytes() {
+    let mut buf = ByteBuf::mut_with_capacity(32);
+    buf.write(&b"hello "[..]).unwrap();
+    assert_eq!(&b"hello "[..], buf.bytes());
+
+    buf.write(&b"world"[..]).unwrap();
+    assert_eq!(&b"hello world"[..], buf.bytes());
+    let buf = buf.flip();
+    assert_eq!(&b"hello world"[..], buf.bytes());
+}
+
 #[test]
 pub fn test_byte_buf_read_write() {
     let mut buf = ByteBuf::mut_with_capacity(32);