Add From<anyhow::Error> for Box<dyn std::error::Error>

src/error.rs

@@ -572,6 +572,12 @@ impl From<Error> for Box<dyn StdError + Send + Sync + 'static> {
     }
 }
 
+impl From<Error> for Box<dyn StdError + 'static> {
+    fn from(error: Error) -> Self {
+        Box::<dyn StdError + Send + Sync>::from(error)
+    }
+}
+
 /// Iterator of a chain of source errors.
 ///
 /// This type is the iterator returned by [`Error::chain`].

tests/test_convert.rs

@@ -1,7 +1,7 @@
 mod drop;
 
 use self::drop::DetectDrop;
-use anyhow::Error;
+use anyhow::{Error, Result};
 use std::error::Error as StdError;
 use std::sync::atomic::AtomicBool;
 use std::sync::atomic::Ordering::SeqCst;
@@ -16,3 +16,12 @@ fn test_convert() {
     drop(box_dyn);
     assert!(has_dropped.load(SeqCst));
 }
+
+#[test]
+fn test_question_mark() -> Result<(), Box<dyn StdError>> {
+    fn f() -> Result<()> {
+        Ok(())
+    }
+    f()?;
+    Ok(())
+}