Accept string literal in bail macro

src/lib.rs

@@ -283,6 +283,9 @@ pub type Result<T> = std::result::Result<T, Error>;
 /// ```
 #[macro_export]
 macro_rules! bail {
+    ($msg:literal $(,)?) => {
+        return std::result::Result::Err($crate::anyhow!($msg));
+    };
     ($err:expr $(,)?) => {
         return std::result::Result::Err(std::convert::From::from($err));
     };

tests/macros.rs

@@ -0,0 +1,28 @@
+use anyhow::{bail, Result};
+use std::io;
+
+fn bail_literal() -> Result<()> {
+    bail!("oh no!");
+}
+
+fn bail_fmt() -> Result<()> {
+    bail!("{} {}!", "oh", "no");
+}
+
+fn bail_error() -> Result<()> {
+    bail!(io::Error::new(io::ErrorKind::Other, "oh no!"));
+}
+
+#[test]
+fn test_messages() {
+    assert_eq!("oh no!", bail_literal().unwrap_err().to_string());
+    assert_eq!("oh no!", bail_fmt().unwrap_err().to_string());
+    assert_eq!("oh no!", bail_error().unwrap_err().to_string());
+}
+
+#[test]
+fn test_downcast() {
+    assert_eq!("oh no!", bail_literal().unwrap_err().downcast::<&str>().unwrap());
+    assert_eq!("oh no!", bail_fmt().unwrap_err().downcast::<String>().unwrap());
+    assert_eq!("oh no!", bail_error().unwrap_err().downcast::<io::Error>().unwrap().to_string());
+}