Auto merge of #42644 - frewsxcv:rollup, r=frewsxcv

Rollup of 6 pull requests

- Successful merges: #42408, #42428, #42496, #42597, #42636, #42638
- Failed merges: #42612

4 files changed, 83 insertions, 43 deletions

diff --git a/src/libcore/cmp.rs b/src/libcore/cmp.rs
index 661cf73c7f3..6f35d0417f1 100644
--- a/src/libcore/cmp.rs
+++ b/src/libcore/cmp.rs
@@ -443,6 +443,42 @@ pub trait Ord: Eq + PartialOrd<Self> {
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
     fn cmp(&self, other: &Self) -> Ordering;
+
+    /// Compares and returns the maximum of two values.
+    ///
+    /// Returns the second argument if the comparison determines them to be equal.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(ord_max_min)]
+    ///
+    /// assert_eq!(2, 1.max(2));
+    /// assert_eq!(2, 2.max(2));
+    /// ```
+    #[unstable(feature = "ord_max_min", issue = "25663")]
+    fn max(self, other: Self) -> Self
+    where Self: Sized {
+        if other >= self { other } else { self }
+    }
+
+    /// Compares and returns the minimum of two values.
+    ///
+    /// Returns the first argument if the comparison determines them to be equal.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(ord_max_min)]
+    ///
+    /// assert_eq!(1, 1.min(2));
+    /// assert_eq!(2, 2.min(2));
+    /// ```
+    #[unstable(feature = "ord_max_min", issue = "25663")]
+    fn min(self, other: Self) -> Self
+    where Self: Sized {
+        if self <= other { self } else { other }
+    }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -678,6 +714,8 @@ pub trait PartialOrd<Rhs: ?Sized = Self>: PartialEq<Rhs> {
 ///
 /// Returns the first argument if the comparison determines them to be equal.
 ///
+/// Internally uses an alias to `Ord::min`.
+///
 /// # Examples
 ///
 /// ```
@@ -689,13 +727,15 @@ pub trait PartialOrd<Rhs: ?Sized = Self>: PartialEq<Rhs> {
 #[inline]
 #[stable(feature = "rust1", since = "1.0.0")]
 pub fn min<T: Ord>(v1: T, v2: T) -> T {
-    if v1 <= v2 { v1 } else { v2 }
+    v1.min(v2)
 }
 
 /// Compares and returns the maximum of two values.
 ///
 /// Returns the second argument if the comparison determines them to be equal.
 ///
+/// Internally uses an alias to `Ord::max`.
+///
 /// # Examples
 ///
 /// ```
@@ -707,7 +747,7 @@ pub fn min<T: Ord>(v1: T, v2: T) -> T {
 #[inline]
 #[stable(feature = "rust1", since = "1.0.0")]
 pub fn max<T: Ord>(v1: T, v2: T) -> T {
-    if v2 >= v1 { v2 } else { v1 }
+    v1.max(v2)
 }
 
 // Implementation of PartialEq, Eq, PartialOrd and Ord for primitive types
diff --git a/src/libcore/str/mod.rs b/src/libcore/str/mod.rs
index 547a4899c71..34aca592b1e 100644
--- a/src/libcore/str/mod.rs
+++ b/src/libcore/str/mod.rs
@@ -1617,12 +1617,7 @@ mod traits {
 
         #[inline]
         fn index(&self, index: ops::RangeTo<usize>) -> &str {
-            // is_char_boundary checks that the index is in [0, .len()]
-            if self.is_char_boundary(index.end) {
-                unsafe { self.slice_unchecked(0, index.end) }
-            } else {
-                super::slice_error_fail(self, 0, index.end)
-            }
+            index.index(self)
         }
     }
 
@@ -1636,12 +1631,7 @@ mod traits {
     impl ops::IndexMut<ops::RangeTo<usize>> for str {
         #[inline]
         fn index_mut(&mut self, index: ops::RangeTo<usize>) -> &mut str {
-            // is_char_boundary checks that the index is in [0, .len()]
-            if self.is_char_boundary(index.end) {
-                unsafe { self.slice_mut_unchecked(0, index.end) }
-            } else {
-                super::slice_error_fail(self, 0, index.end)
-            }
+            index.index_mut(self)
         }
     }
 
@@ -1657,12 +1647,7 @@ mod traits {
 
         #[inline]
         fn index(&self, index: ops::RangeFrom<usize>) -> &str {
-            // is_char_boundary checks that the index is in [0, .len()]
-            if self.is_char_boundary(index.start) {
-                unsafe { self.slice_unchecked(index.start, self.len()) }
-            } else {
-                super::slice_error_fail(self, index.start, self.len())
-            }
+            index.index(self)
         }
     }
 
@@ -1676,13 +1661,7 @@ mod traits {
     impl ops::IndexMut<ops::RangeFrom<usize>> for str {
         #[inline]
         fn index_mut(&mut self, index: ops::RangeFrom<usize>) -> &mut str {
-            // is_char_boundary checks that the index is in [0, .len()]
-            if self.is_char_boundary(index.start) {
-                let len = self.len();
-                unsafe { self.slice_mut_unchecked(index.start, len) }
-            } else {
-                super::slice_error_fail(self, index.start, self.len())
-            }
+            index.index_mut(self)
         }
     }
 
@@ -1724,9 +1703,7 @@ mod traits {
 
         #[inline]
         fn index(&self, index: ops::RangeInclusive<usize>) -> &str {
-            assert!(index.end != usize::max_value(),
-                "attempted to index str up to maximum usize");
-            self.index(index.start .. index.end+1)
+            index.index(self)
         }
     }
 
@@ -1738,9 +1715,7 @@ mod traits {
 
         #[inline]
         fn index(&self, index: ops::RangeToInclusive<usize>) -> &str {
-            assert!(index.end != usize::max_value(),
-                "attempted to index str up to maximum usize");
-            self.index(.. index.end+1)
+            index.index(self)
         }
     }
 
@@ -1750,9 +1725,7 @@ mod traits {
     impl ops::IndexMut<ops::RangeInclusive<usize>> for str {
         #[inline]
         fn index_mut(&mut self, index: ops::RangeInclusive<usize>) -> &mut str {
-            assert!(index.end != usize::max_value(),
-                "attempted to index str up to maximum usize");
-            self.index_mut(index.start .. index.end+1)
+            index.index_mut(self)
         }
     }
     #[unstable(feature = "inclusive_range",
@@ -1761,9 +1734,7 @@ mod traits {
     impl ops::IndexMut<ops::RangeToInclusive<usize>> for str {
         #[inline]
         fn index_mut(&mut self, index: ops::RangeToInclusive<usize>) -> &mut str {
-            assert!(index.end != usize::max_value(),
-                "attempted to index str up to maximum usize");
-            self.index_mut(.. index.end+1)
+            index.index_mut(self)
         }
     }
 
@@ -1886,6 +1857,7 @@ mod traits {
         }
         #[inline]
         fn index_mut(self, slice: &mut str) -> &mut Self::Output {
+            // is_char_boundary checks that the index is in [0, .len()]
             if slice.is_char_boundary(self.end) {
                 unsafe { self.get_unchecked_mut(slice) }
             } else {
@@ -1932,6 +1904,7 @@ mod traits {
         }
         #[inline]
         fn index_mut(self, slice: &mut str) -> &mut Self::Output {
+            // is_char_boundary checks that the index is in [0, .len()]
             if slice.is_char_boundary(self.start) {
                 unsafe { self.get_unchecked_mut(slice) }
             } else {
@@ -1945,11 +1918,19 @@ mod traits {
         type Output = str;
         #[inline]
         fn get(self, slice: &str) -> Option<&Self::Output> {
-            (self.start..self.end+1).get(slice)
+            if let Some(end) = self.end.checked_add(1) {
+                (self.start..end).get(slice)
+            } else {
+                None
+            }
         }
         #[inline]
         fn get_mut(self, slice: &mut str) -> Option<&mut Self::Output> {
-            (self.start..self.end+1).get_mut(slice)
+            if let Some(end) = self.end.checked_add(1) {
+                (self.start..end).get_mut(slice)
+            } else {
+                None
+            }
         }
         #[inline]
         unsafe fn get_unchecked(self, slice: &str) -> &Self::Output {
@@ -1961,10 +1942,14 @@ mod traits {
         }
         #[inline]
         fn index(self, slice: &str) -> &Self::Output {
+            assert!(self.end != usize::max_value(),
+                "attempted to index str up to maximum usize");
             (self.start..self.end+1).index(slice)
         }
         #[inline]
         fn index_mut(self, slice: &mut str) -> &mut Self::Output {
+            assert!(self.end != usize::max_value(),
+                "attempted to index str up to maximum usize");
             (self.start..self.end+1).index_mut(slice)
         }
     }
@@ -1976,7 +1961,7 @@ mod traits {
         type Output = str;
         #[inline]
         fn get(self, slice: &str) -> Option<&Self::Output> {
-            if slice.is_char_boundary(self.end + 1) {
+            if self.end < usize::max_value() && slice.is_char_boundary(self.end + 1) {
                 Some(unsafe { self.get_unchecked(slice) })
             } else {
                 None
@@ -1984,7 +1969,7 @@ mod traits {
         }
         #[inline]
         fn get_mut(self, slice: &mut str) -> Option<&mut Self::Output> {
-            if slice.is_char_boundary(self.end + 1) {
+            if self.end < usize::max_value() && slice.is_char_boundary(self.end + 1) {
                 Some(unsafe { self.get_unchecked_mut(slice) })
             } else {
                 None
@@ -2002,11 +1987,15 @@ mod traits {
         }
         #[inline]
         fn index(self, slice: &str) -> &Self::Output {
+            assert!(self.end != usize::max_value(),
+                "attempted to index str up to maximum usize");
             let end = self.end + 1;
             self.get(slice).unwrap_or_else(|| super::slice_error_fail(slice, 0, end))
         }
         #[inline]
         fn index_mut(self, slice: &mut str) -> &mut Self::Output {
+            assert!(self.end != usize::max_value(),
+                "attempted to index str up to maximum usize");
             if slice.is_char_boundary(self.end) {
                 unsafe { self.get_unchecked_mut(slice) }
             } else {
diff --git a/src/libcore/tests/cmp.rs b/src/libcore/tests/cmp.rs
index e3c65ad8b33..8c5179f5993 100644
--- a/src/libcore/tests/cmp.rs
+++ b/src/libcore/tests/cmp.rs
@@ -29,6 +29,16 @@ fn test_mut_int_totalord() {
 }
 
 #[test]
+fn test_ord_max_min() {
+    assert_eq!(1.max(2), 2);
+    assert_eq!(2.max(1), 2);
+    assert_eq!(1.min(2), 1);
+    assert_eq!(2.min(1), 1);
+    assert_eq!(1.max(1), 1);
+    assert_eq!(1.min(1), 1);
+}
+
+#[test]
 fn test_ordering_reverse() {
     assert_eq!(Less.reverse(), Greater);
     assert_eq!(Equal.reverse(), Equal);
diff --git a/src/libcore/tests/lib.rs b/src/libcore/tests/lib.rs
index 505e51fa80b..77a9307f43e 100644
--- a/src/libcore/tests/lib.rs
+++ b/src/libcore/tests/lib.rs
@@ -26,6 +26,7 @@
 #![feature(iter_rfind)]
 #![feature(libc)]
 #![feature(nonzero)]
+#![feature(ord_max_min)]
 #![feature(rand)]
 #![feature(raw)]
 #![feature(sip_hash_13)]