From 0e26bb728784c8e98c8e67eb2c60e88733167d03 Mon Sep 17 00:00:00 2001
From: Tatsuyuki Ishi <ishitatsuyuki@gmail.com>
Date: Sun, 18 Feb 2018 11:36:41 +0900
Subject: [PATCH] Revert "Implement Ord as necessary"

This reverts commit c6772b4dcb95137e88d5cd1814ce0051f74a3c29.
---
 src/librustc/traits/project.rs |  2 +-
 src/librustc/ty/mod.rs         | 30 +-----------------------------
 src/librustc/ty/sty.rs         |  4 ++--
 src/librustc/ty/subst.rs       |  2 +-
 4 files changed, 5 insertions(+), 33 deletions(-)

diff --git a/src/librustc/traits/project.rs b/src/librustc/traits/project.rs
index ae539f07336d..7ae969119415 100644
--- a/src/librustc/traits/project.rs
+++ b/src/librustc/traits/project.rs
@@ -101,7 +101,7 @@ pub struct MismatchedProjectionTypes<'tcx> {
     pub err: ty::error::TypeError<'tcx>
 }
 
-#[derive(PartialEq, Eq, PartialOrd, Ord, Debug)]
+#[derive(PartialEq, Eq, Debug)]
 enum ProjectionTyCandidate<'tcx> {
     // from a where-clause in the env or object type
     ParamEnv(ty::PolyProjectionPredicate<'tcx>),
diff --git a/src/librustc/ty/mod.rs b/src/librustc/ty/mod.rs
index f52f2ea0f9fc..14d33b0729aa 100644
--- a/src/librustc/ty/mod.rs
+++ b/src/librustc/ty/mod.rs
@@ -39,7 +39,6 @@ use util::nodemap::{NodeSet, DefIdMap, FxHashMap, FxHashSet};
 use serialize::{self, Encodable, Encoder};
 use std::cell::RefCell;
 use std::cmp;
-use std::cmp::Ordering;
 use std::fmt;
 use std::hash::{Hash, Hasher};
 use std::iter::FromIterator;
@@ -498,20 +497,6 @@ impl<'tcx> Hash for TyS<'tcx> {
     }
 }
 
-impl<'tcx> Ord for TyS<'tcx> {
-    #[inline]
-    fn cmp(&self, other: &TyS<'tcx>) -> Ordering {
-        // (self as *const _).cmp(other as *const _)
-        (self as *const TyS<'tcx>).cmp(&(other as *const TyS<'tcx>))
-    }
-}
-impl<'tcx> PartialOrd for TyS<'tcx> {
-    #[inline]
-    fn partial_cmp(&self, other: &TyS<'tcx>) -> Option<Ordering> {
-        Some(self.cmp(other))
-    }
-}
-
 impl<'tcx> TyS<'tcx> {
     pub fn is_primitive_ty(&self) -> bool {
         match self.sty {
@@ -581,19 +566,6 @@ impl<T> PartialEq for Slice<T> {
 }
 impl<T> Eq for Slice<T> {}
 
-impl<T> Ord for Slice<T> {
-    #[inline]
-    fn cmp(&self, other: &Slice<T>) -> Ordering {
-        (&self.0 as *const [T]).cmp(&(&other.0 as *const [T]))
-    }
-}
-impl<T> PartialOrd for Slice<T> {
-    #[inline]
-    fn partial_cmp(&self, other: &Slice<T>) -> Option<Ordering> {
-        Some(self.cmp(other))
-    }
-}
-
 impl<T> Hash for Slice<T> {
     fn hash<H: Hasher>(&self, s: &mut H) {
         (self.as_ptr(), self.len()).hash(s)
@@ -1128,7 +1100,7 @@ pub type PolySubtypePredicate<'tcx> = ty::Binder<SubtypePredicate<'tcx>>;
 /// equality between arbitrary types. Processing an instance of
 /// Form #2 eventually yields one of these `ProjectionPredicate`
 /// instances to normalize the LHS.
-#[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, RustcEncodable, RustcDecodable)]
+#[derive(Copy, Clone, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable)]
 pub struct ProjectionPredicate<'tcx> {
     pub projection_ty: ProjectionTy<'tcx>,
     pub ty: Ty<'tcx>,
diff --git a/src/librustc/ty/sty.rs b/src/librustc/ty/sty.rs
index 961c2650afde..503418b044f4 100644
--- a/src/librustc/ty/sty.rs
+++ b/src/librustc/ty/sty.rs
@@ -645,7 +645,7 @@ impl<'tcx> PolyExistentialTraitRef<'tcx> {
 /// erase, or otherwise "discharge" these bound regions, we change the
 /// type from `Binder<T>` to just `T` (see
 /// e.g. `liberate_late_bound_regions`).
-#[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Debug, RustcEncodable, RustcDecodable)]
+#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug, RustcEncodable, RustcDecodable)]
 pub struct Binder<T>(pub T);
 
 impl<T> Binder<T> {
@@ -745,7 +745,7 @@ impl<T> Binder<T> {
 
 /// Represents the projection of an associated type. In explicit UFCS
 /// form this would be written `<T as Trait<..>>::N`.
-#[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Debug, RustcEncodable, RustcDecodable)]
+#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug, RustcEncodable, RustcDecodable)]
 pub struct ProjectionTy<'tcx> {
     /// The parameters of the associated item.
     pub substs: &'tcx Substs<'tcx>,
diff --git a/src/librustc/ty/subst.rs b/src/librustc/ty/subst.rs
index 7c167f69ebd8..80b113dfdf5a 100644
--- a/src/librustc/ty/subst.rs
+++ b/src/librustc/ty/subst.rs
@@ -29,7 +29,7 @@ use std::mem;
 /// To reduce memory usage, a `Kind` is a interned pointer,
 /// with the lowest 2 bits being reserved for a tag to
 /// indicate the type (`Ty` or `Region`) it points to.
-#[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
+#[derive(Copy, Clone, PartialEq, Eq, Hash)]
 pub struct Kind<'tcx> {
     ptr: NonZero<usize>,
     marker: PhantomData<(Ty<'tcx>, ty::Region<'tcx>)>