Added `impl Div<NonZeroU{0}> for u{0}` which cannot panic

2 files changed, 37 insertions, 1 deletions

diff --git a/library/core/src/num/nonzero.rs b/library/core/src/num/nonzero.rs
index 716b4a90e5e..3355fb64ecf 100644
--- a/library/core/src/num/nonzero.rs
+++ b/library/core/src/num/nonzero.rs
@@ -1,7 +1,7 @@
 //! Definitions of integer that is known not to equal zero.
 
 use crate::fmt;
-use crate::ops::{BitOr, BitOrAssign};
+use crate::ops::{BitOr, BitOrAssign, Div};
 use crate::str::FromStr;
 
 use super::from_str_radix;
@@ -263,3 +263,31 @@ nonzero_leading_trailing_zeros! {
     NonZeroI128(u128), -1i128;
     NonZeroIsize(usize), -1isize;
 }
+
+macro_rules! nonzero_integers_div {
+    ( $( $Ty: ident($Int: ty); )+ ) => {
+        $(
+            #[stable(feature = "nonzero_div", since = "1.50.0")]
+            impl Div<$Ty> for $Int {
+                type Output = $Int;
+                /// This operation rounds towards zero,
+                /// truncating any fractional part of the exact result, and cannot panic.
+                #[inline]
+                fn div(self, other: $Ty) -> $Int {
+                    // SAFETY: div by zero is checked because `other` is a nonzero,
+                    // and MIN/-1 is checked because `self` is an unsigned int.
+                    unsafe { crate::intrinsics::unchecked_div(self, other.get()) }
+                }
+            }
+        )+
+    }
+}
+
+nonzero_integers_div! {
+    NonZeroU8(u8);
+    NonZeroU16(u16);
+    NonZeroU32(u32);
+    NonZeroU64(u64);
+    NonZeroU128(u128);
+    NonZeroUsize(usize);
+}
diff --git a/library/core/tests/nonzero.rs b/library/core/tests/nonzero.rs
index b66c482c5e5..6ec3a04adc0 100644
--- a/library/core/tests/nonzero.rs
+++ b/library/core/tests/nonzero.rs
@@ -312,3 +312,11 @@ fn nonzero_trailing_zeros() {
     const TRAILING_ZEROS: u32 = NonZeroU16::new(1 << 2).unwrap().trailing_zeros();
     assert_eq!(TRAILING_ZEROS, 2);
 }
+
+#[test]
+fn test_nonzero_uint_div() {
+    let nz = NonZeroU32::new(1).unwrap();
+
+    let x: u32 = 42u32 / nz;
+    assert_eq!(x, 42u32);
+}