Factor usage of common error type more

daqbufp2/src/err.rs

@@ -0,0 +1,18 @@
+pub trait ErrConv<T> {
+    fn ec(self) -> Result<T, ::err::Error>;
+}
+
+pub trait Convable: ToString {}
+
+impl<T, E: Convable> ErrConv<T> for Result<T, E> {
+    fn ec(self) -> Result<T, err::Error> {
+        match self {
+            Ok(x) => Ok(x),
+            Err(e) => Err(::err::Error::from_string(e.to_string())),
+        }
+    }
+}
+
+impl Convable for http::Error {}
+impl Convable for hyper::Error {}
+impl Convable for tokio::task::JoinError {}