From 6bb3acab74f9cf4bf3d3b81f0805416cd7b3ee20 Mon Sep 17 00:00:00 2001
From: Michael Watzko <michael@watzko.de>
Date: Thu, 19 Aug 2021 11:06:08 +0200
Subject: [PATCH] Add doctests to and fix saturating_div for signed integer
 types

---
 library/core/src/num/int_macros.rs | 31 +++++++++++++++++++++---------
 library/std/src/lib.rs             |  1 +
 2 files changed, 23 insertions(+), 9 deletions(-)

diff --git a/library/core/src/num/int_macros.rs b/library/core/src/num/int_macros.rs
index f5966a53ed2..7c36f4cdd20 100644
--- a/library/core/src/num/int_macros.rs
+++ b/library/core/src/num/int_macros.rs
@@ -926,21 +926,34 @@ pub const fn saturating_mul(self, rhs: Self) -> Self {
         /// Basic usage:
         ///
         /// ```
+        /// #![feature(saturating_div)]
+        ///
+        #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".saturating_div(2), 2);")]
+        #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.saturating_div(-1), ", stringify!($SelfT), "::MIN + 1);")]
+        #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_div(-1), ", stringify!($SelfT), "::MAX);")]
         ///
         /// ```
-        #[unstable(feature = "saturating_int_impl", issue = "87920")]
-        #[rustc_const_unstable(feature = "saturating_int_impl", issue = "87920")]
+        ///
+        /// ```should_panic
+        /// #![feature(saturating_div)]
+        ///
+        #[doc = concat!("let _ = 1", stringify!($SelfT), ".saturating_div(0);")]
+        ///
+        /// ```
+        #[unstable(feature = "saturating_div", issue = "87920")]
+        #[rustc_const_unstable(feature = "saturating_div", issue = "87920")]
         #[must_use = "this returns the result of the operation, \
                       without modifying the original"]
         #[inline]
         pub const fn saturating_div(self, rhs: Self) -> Self {
-            match self.checked_div(rhs) {
-                Some(x) => x,
-                None => if (self < 0) == (rhs < 0) {
-                    Self::MAX
-                } else {
-                    Self::MIN
-                }
+            let (result, overflowed) = self.overflowing_div(rhs);
+
+            if !overflowed {
+                result
+            } else if (self < 0) == (rhs < 0) {
+                Self::MAX
+            } else {
+                Self::MIN
             }
         }
 
diff --git a/library/std/src/lib.rs b/library/std/src/lib.rs
index 818ca7df3e3..676ca5dea5d 100644
--- a/library/std/src/lib.rs
+++ b/library/std/src/lib.rs
@@ -308,6 +308,7 @@
 #![feature(ptr_internals)]
 #![feature(rustc_attrs)]
 #![feature(rustc_private)]
+#![feature(saturating_div)]
 #![feature(saturating_int_impl)]
 #![feature(slice_concat_ext)]
 #![feature(slice_internals)]
-- 
2.44.0