add error module

src/error.rs

@@ -0,0 +1,22 @@
+/// Wrapper around the raw `ErrorKind`
+#[derive(Clone, Debug, PartialEq, Eq, Hash)]
+pub struct Error {
+    kind: ErrorKind,
+}
+
+impl Error {
+    pub fn from_kind(kind: ErrorKind) -> Error {
+        Error { kind }
+    }
+
+    pub fn kind(&self) -> ErrorKind {
+        self.kind
+    }
+}
+
+/// The set of all possible errors
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
+pub enum ErrorKind {
+    BadMagic,
+    OutOfBounds,
+}