diff --git a/library/core/src/num/nonzero.rs b/library/core/src/num/nonzero.rs index 716b4a90e5e..5eb70026d7e 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, Rem}; use crate::str::FromStr; use super::from_str_radix; @@ -263,3 +263,43 @@ nonzero_leading_trailing_zeros! { NonZeroI128(u128), -1i128; NonZeroIsize(usize), -1isize; } + +macro_rules! nonzero_integers_div { + ( $( $Ty: ident($Int: ty); )+ ) => { + $( + #[stable(feature = "nonzero_div", since = "1.51.0")] + impl Div<$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) -> $Int { + // SAFETY: div by zero is checked because `other` is a nonzero, + // and MIN/-1 is checked because `self` is an unsigned int. + unsafe { crate::intrinsics::unchecked_div(self, other.get()) } + } + } + + #[stable(feature = "nonzero_div", since = "1.51.0")] + impl Rem<$Ty> for $Int { + type Output = $Int; + /// This operation satisfies `n % d == n - (n / d) * d`, and cannot panic. + #[inline] + fn rem(self, other: $Ty) -> $Int { + // SAFETY: rem by zero is checked because `other` is a nonzero, + // and MIN/-1 is checked because `self` is an unsigned int. + unsafe { crate::intrinsics::unchecked_rem(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..c2c08522d0c 100644 --- a/library/core/tests/nonzero.rs +++ b/library/core/tests/nonzero.rs @@ -312,3 +312,19 @@ 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); +} + +#[test] +fn test_nonzero_uint_rem() { + let nz = NonZeroU32::new(10).unwrap(); + + let x: u32 = 42u32 % nz; + assert_eq!(x, 2u32); +}