1 files changed, 29 insertions, 53 deletions

diff --git a/library/core/src/cmp.rs b/library/core/src/cmp.rs
index 949896e57..a7d6fec7d 100644
--- a/library/core/src/cmp.rs
+++ b/library/core/src/cmp.rs
@@ -24,8 +24,6 @@
 
 use crate::const_closure::ConstFnMutClosure;
 use crate::marker::Destruct;
-#[cfg(bootstrap)]
-use crate::marker::StructuralPartialEq;
 
 use self::Ordering::*;
 
@@ -333,7 +331,7 @@ pub struct AssertParamIsEq<T: Eq + ?Sized> {
 /// assert_eq!(Ordering::Greater, result);
 /// ```
 #[derive(Clone, Copy, Eq, Debug, Hash)]
-#[cfg_attr(not(bootstrap), derive_const(PartialOrd, Ord, PartialEq))]
+#[derive_const(PartialOrd, Ord, PartialEq)]
 #[stable(feature = "rust1", since = "1.0.0")]
 #[repr(i8)]
 pub enum Ordering {
@@ -800,9 +798,12 @@ pub trait Ord: Eq + PartialOrd<Self> {
         Self: Sized,
         Self: ~const Destruct,
     {
-        // HACK(fee1-dead): go back to using `self.max_by(other, Ord::cmp)`
-        // when trait methods are allowed to be used when a const closure is
-        // expected.
+        #[cfg(not(bootstrap))]
+        {
+            max_by(self, other, Ord::cmp)
+        }
+
+        #[cfg(bootstrap)]
         match self.cmp(&other) {
             Ordering::Less | Ordering::Equal => other,
             Ordering::Greater => self,
@@ -827,9 +828,12 @@ pub trait Ord: Eq + PartialOrd<Self> {
         Self: Sized,
         Self: ~const Destruct,
     {
-        // HACK(fee1-dead): go back to using `self.min_by(other, Ord::cmp)`
-        // when trait methods are allowed to be used when a const closure is
-        // expected.
+        #[cfg(not(bootstrap))]
+        {
+            min_by(self, other, Ord::cmp)
+        }
+
+        #[cfg(bootstrap)]
         match self.cmp(&other) {
             Ordering::Less | Ordering::Equal => self,
             Ordering::Greater => other,
@@ -879,40 +883,6 @@ pub macro Ord($item:item) {
     /* compiler built-in */
 }
 
-#[stable(feature = "rust1", since = "1.0.0")]
-#[cfg(bootstrap)]
-impl StructuralPartialEq for Ordering {}
-
-#[stable(feature = "rust1", since = "1.0.0")]
-#[rustc_const_unstable(feature = "const_cmp", issue = "92391")]
-#[cfg(bootstrap)]
-impl const PartialEq for Ordering {
-    #[inline]
-    fn eq(&self, other: &Self) -> bool {
-        (*self as i32).eq(&(*other as i32))
-    }
-}
-
-#[stable(feature = "rust1", since = "1.0.0")]
-#[rustc_const_unstable(feature = "const_cmp", issue = "92391")]
-#[cfg(bootstrap)]
-impl const Ord for Ordering {
-    #[inline]
-    fn cmp(&self, other: &Ordering) -> Ordering {
-        (*self as i32).cmp(&(*other as i32))
-    }
-}
-
-#[stable(feature = "rust1", since = "1.0.0")]
-#[rustc_const_unstable(feature = "const_cmp", issue = "92391")]
-#[cfg(bootstrap)]
-impl const PartialOrd for Ordering {
-    #[inline]
-    fn partial_cmp(&self, other: &Ordering) -> Option<Ordering> {
-        (*self as i32).partial_cmp(&(*other as i32))
-    }
-}
-
 /// Trait for types that form a [partial order](https://en.wikipedia.org/wiki/Partial_order).
 ///
 /// The `lt`, `le`, `gt`, and `ge` methods of this trait can be called using
@@ -1264,17 +1234,23 @@ where
     F: ~const Destruct,
     K: ~const Destruct,
 {
-    const fn imp<T, F: ~const FnMut(&T) -> K, K: ~const Ord>(
-        f: &mut F,
-        (v1, v2): (&T, &T),
-    ) -> Ordering
-    where
-        T: ~const Destruct,
-        K: ~const Destruct,
-    {
-        f(v1).cmp(&f(v2))
+    cfg_if! {
+        if #[cfg(bootstrap)] {
+            const fn imp<T, F: ~const FnMut(&T) -> K, K: ~const Ord>(
+                f: &mut F,
+                (v1, v2): (&T, &T),
+            ) -> Ordering
+            where
+                T: ~const Destruct,
+                K: ~const Destruct,
+            {
+                f(v1).cmp(&f(v2))
+            }
+            min_by(v1, v2, ConstFnMutClosure::new(&mut f, imp))
+        } else {
+            min_by(v1, v2, const |v1, v2| f(v1).cmp(&f(v2)))
+        }
     }
-    min_by(v1, v2, ConstFnMutClosure::new(&mut f, imp))
 }
 
 /// Compares and returns the maximum of two values.