Ensure Error trait implementations

The anyhow crate requires that error types are error::Error, Send, Sync
and 'static.  This patch implements a simple static assertion that our
Error type implements these traits.

1 files changed, 19 insertions, 0 deletions

diff --git a/src/error.rs b/src/error.rs
index 995741b..1aa1793 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -267,3 +267,22 @@ impl fmt::Display for LibraryError {
         })
     }
 }
+
+// build our own static assertion that Error implements error::Error, Send, Sync, 'static
+
+struct Helper<T>(T);
+
+trait Assert {
+    fn assert() -> bool;
+}
+
+impl<T: error::Error + Send + Sync + 'static> Assert for Helper<T> {
+    fn assert() -> bool {
+        true
+    }
+}
+
+#[allow(unused)]
+fn assert_error_impl() {
+    let _ = Helper::<Error>::assert();
+}