From 51c6ae25e286152f44adfdc3d2f88b597fa5fc7a Mon Sep 17 00:00:00 2001
From: Andrew Cann <shum@canndrew.org>
Date: Mon, 1 Aug 2016 12:56:43 +0800
Subject: [PATCH] implement std::cmp::* traits for `!`

---
 src/libcore/cmp.rs | 33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/src/libcore/cmp.rs b/src/libcore/cmp.rs
index 8764766b2ef8..1d2ed735e813 100644
--- a/src/libcore/cmp.rs
+++ b/src/libcore/cmp.rs
@@ -699,6 +699,39 @@ mod impls {
 
     ord_impl! { char usize u8 u16 u32 u64 isize i8 i16 i32 i64 }
 
+    // Note: This macro is a temporary hack that can be remove once we are building with a compiler
+    // that supports `!`
+    macro_rules! argh {
+        () => {
+            #[unstable(feature = "bang_type", issue = "35121")]
+            impl PartialEq for ! {
+                fn eq(&self, _: &!) -> bool {
+                    *self
+                }
+            }
+
+            #[unstable(feature = "bang_type", issue = "35121")]
+            impl Eq for ! {}
+
+            #[unstable(feature = "bang_type", issue = "35121")]
+            impl PartialOrd for ! {
+                fn partial_cmp(&self, _: &!) -> Option<Ordering> {
+                    *self
+                }
+            }
+
+            #[unstable(feature = "bang_type", issue = "35121")]
+            impl Ord for ! {
+                fn cmp(&self, _: &!) -> Ordering {
+                    *self
+                }
+            }
+        }
+    }
+
+    #[cfg(not(stage0))]
+    argh!();
+
     // & pointers
 
     #[stable(feature = "rust1", since = "1.0.0")]