1 files changed, 12 insertions, 69 deletions

diff --git a/library/core/src/cmp.rs b/library/core/src/cmp.rs
index a7d6fec7d..068637d1a 100644
--- a/library/core/src/cmp.rs
+++ b/library/core/src/cmp.rs
@@ -22,7 +22,9 @@
 
 #![stable(feature = "rust1", since = "1.0.0")]
 
-use crate::const_closure::ConstFnMutClosure;
+mod bytewise;
+pub(crate) use bytewise::BytewiseEq;
+
 use crate::marker::Destruct;
 
 use self::Ordering::*;
@@ -798,12 +800,6 @@ pub trait Ord: Eq + PartialOrd<Self> {
         Self: Sized,
         Self: ~const Destruct,
     {
-        #[cfg(not(bootstrap))]
-        {
-            max_by(self, other, Ord::cmp)
-        }
-
-        #[cfg(bootstrap)]
         match self.cmp(&other) {
             Ordering::Less | Ordering::Equal => other,
             Ordering::Greater => self,
@@ -828,12 +824,6 @@ pub trait Ord: Eq + PartialOrd<Self> {
         Self: Sized,
         Self: ~const Destruct,
     {
-        #[cfg(not(bootstrap))]
-        {
-            min_by(self, other, Ord::cmp)
-        }
-
-        #[cfg(bootstrap)]
         match self.cmp(&other) {
             Ordering::Less | Ordering::Equal => self,
             Ordering::Greater => other,
@@ -1200,12 +1190,7 @@ pub const fn min<T: ~const Ord + ~const Destruct>(v1: T, v2: T) -> T {
 #[inline]
 #[must_use]
 #[stable(feature = "cmp_min_max_by", since = "1.53.0")]
-#[rustc_const_unstable(feature = "const_cmp", issue = "92391")]
-pub const fn min_by<T, F: ~const FnOnce(&T, &T) -> Ordering>(v1: T, v2: T, compare: F) -> T
-where
-    T: ~const Destruct,
-    F: ~const Destruct,
-{
+pub fn min_by<T, F: FnOnce(&T, &T) -> Ordering>(v1: T, v2: T, compare: F) -> T {
     match compare(&v1, &v2) {
         Ordering::Less | Ordering::Equal => v1,
         Ordering::Greater => v2,
@@ -1227,30 +1212,8 @@ where
 #[inline]
 #[must_use]
 #[stable(feature = "cmp_min_max_by", since = "1.53.0")]
-#[rustc_const_unstable(feature = "const_cmp", issue = "92391")]
-pub const fn min_by_key<T, F: ~const FnMut(&T) -> K, K: ~const Ord>(v1: T, v2: T, mut f: F) -> T
-where
-    T: ~const Destruct,
-    F: ~const Destruct,
-    K: ~const Destruct,
-{
-    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)))
-        }
-    }
+pub fn min_by_key<T, F: FnMut(&T) -> K, K: Ord>(v1: T, v2: T, mut f: F) -> T {
+    min_by(v1, v2, |v1, v2| f(v1).cmp(&f(v2)))
 }
 
 /// Compares and returns the maximum of two values.
@@ -1291,12 +1254,7 @@ pub const fn max<T: ~const Ord + ~const Destruct>(v1: T, v2: T) -> T {
 #[inline]
 #[must_use]
 #[stable(feature = "cmp_min_max_by", since = "1.53.0")]
-#[rustc_const_unstable(feature = "const_cmp", issue = "92391")]
-pub const fn max_by<T, F: ~const FnOnce(&T, &T) -> Ordering>(v1: T, v2: T, compare: F) -> T
-where
-    T: ~const Destruct,
-    F: ~const Destruct,
-{
+pub fn max_by<T, F: FnOnce(&T, &T) -> Ordering>(v1: T, v2: T, compare: F) -> T {
     match compare(&v1, &v2) {
         Ordering::Less | Ordering::Equal => v2,
         Ordering::Greater => v1,
@@ -1318,24 +1276,8 @@ where
 #[inline]
 #[must_use]
 #[stable(feature = "cmp_min_max_by", since = "1.53.0")]
-#[rustc_const_unstable(feature = "const_cmp", issue = "92391")]
-pub const fn max_by_key<T, F: ~const FnMut(&T) -> K, K: ~const Ord>(v1: T, v2: T, mut f: F) -> T
-where
-    T: ~const Destruct,
-    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))
-    }
-    max_by(v1, v2, ConstFnMutClosure::new(&mut f, imp))
+pub fn max_by_key<T, F: FnMut(&T) -> K, K: Ord>(v1: T, v2: T, mut f: F) -> T {
+    max_by(v1, v2, |v1, v2| f(v1).cmp(&f(v2)))
 }
 
 // Implementation of PartialEq, Eq, PartialOrd and Ord for primitive types
@@ -1536,9 +1478,10 @@ mod impls {
         }
     }
     #[stable(feature = "rust1", since = "1.0.0")]
-    impl<A: ?Sized, B: ?Sized> PartialOrd<&B> for &A
+    #[rustc_const_unstable(feature = "const_cmp", issue = "92391")]
+    impl<A: ?Sized, B: ?Sized> const PartialOrd<&B> for &A
     where
-        A: PartialOrd<B>,
+        A: ~const PartialOrd<B>,
     {
         #[inline]
         fn partial_cmp(&self, other: &&B) -> Option<Ordering> {