Implement Error for ReadError

usdpl-back/src/api_common/files.rs

@@ -13,6 +13,7 @@ pub fn write_single<P: AsRef<Path>, D: Display>(path: P, display: D) -> Result<(
 }
 
 /// read_single error
+#[derive(Debug)]
 pub enum ReadError<E> {
     /// IO Error
     Io(io::Error),
@@ -20,6 +21,19 @@ pub enum ReadError<E> {
     Parse(E),
 }
 
+impl<E: std::error::Error> std::fmt::Display for ReadError<E> {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Self::Io(io) => write!(f, "io: {}", io),
+            Self::Parse(e) => write!(f, "parse: {}", e),
+        }
+    }
+}
+
+impl<E: std::error::Error> std::error::Error for ReadError<E> {
+
+}
+
 /// Read something from a file.
 /// Useful for kernel configuration files.
 pub fn read_single<P: AsRef<Path>, D: FromStr<Err=E>, E>(path: P) -> Result<D, ReadError<E>> {