Add kind method

src/lib.rs

@@ -54,6 +54,15 @@ pub enum Error {
     Canceled,
 }
 
+impl Error {
+    pub fn kind(&self) -> Option<io::ErrorKind> {
+        match self {
+            Error::Io(ref io) => Some(io.kind()),
+            _ => None,
+        }
+    }
+}
+
 impl From<std::str::Utf8Error> for Error {
     fn from(e: std::str::Utf8Error) -> Self {
         Error::Io(io::Error::new(io::ErrorKind::InvalidInput, e))