1 files changed, 30 insertions, 0 deletions
diff --git a/src/librustc_mir/const_eval/error.rs b/src/librustc_mir/const_eval/error.rs
new file mode 100644
index 00000000000..8948cc0fc3e
--- /dev/null
+++ b/src/librustc_mir/const_eval/error.rs
@@ -0,0 +1,30 @@
+use std::error::Error;
+use std::fmt;
+
+use crate::interpret::InterpErrorInfo;
+
+#[derive(Clone, Debug)]
+pub enum ConstEvalError {
+    NeedsRfc(String),
+    ConstAccessesStatic,
+}
+
+impl<'tcx> Into<InterpErrorInfo<'tcx>> for ConstEvalError {
+    fn into(self) -> InterpErrorInfo<'tcx> {
+        err_unsup!(Unsupported(self.to_string())).into()
+    }
+}
+
+impl fmt::Display for ConstEvalError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        use self::ConstEvalError::*;
+        match *self {
+            NeedsRfc(ref msg) => {
+                write!(f, "\"{}\" needs an rfc before being allowed inside constants", msg)
+            }
+            ConstAccessesStatic => write!(f, "constant accesses static"),
+        }
+    }
+}
+
+impl Error for ConstEvalError {}