1 files changed, 24 insertions, 0 deletions
diff --git a/src/never.rs b/src/never.rs
new file mode 100644
index 0000000..b4bb371
--- /dev/null
+++ b/src/never.rs
@@ -0,0 +1,24 @@
+use std::error;
+use std::fmt;
+
+/// Definition of an empty enum.
+///
+/// This is used as the error type in situations where there can't be an error. A `Result<T, Never>`
+/// can be safely unwrapped and the `unwrap()` may be optimized away entirely.
+///
+/// This error is typically encountered when attempting to get tokens from the `Tokenizer`. Call
+/// [`Tokenizer::infallible`] if you wish to avoid unwrapping those results yourself.
+pub enum Never {}
+
+impl fmt::Display for Never {
+    fn fmt(&self, _: &mut fmt::Formatter<'_>) -> Result<(), std::fmt::Error> {
+        match *self {}
+    }
+}
+impl fmt::Debug for Never {
+    fn fmt(&self, _: &mut fmt::Formatter<'_>) -> Result<(), std::fmt::Error> {
+        match *self {}
+    }
+}
+
+impl error::Error for Never {}