diff --git a/library/core/src/num/mod.rs b/library/core/src/num/mod.rs
index 695e87aaabf8a..f5d765e690db4 100644
--- a/library/core/src/num/mod.rs
+++ b/library/core/src/num/mod.rs
@@ -59,6 +59,8 @@ pub use dec2flt::ParseFloatError;
#[stable(feature = "rust1", since = "1.0.0")]
pub use error::ParseIntError;
+pub(crate) use nonzero::NonZero;
+
#[stable(feature = "nonzero", since = "1.28.0")]
pub use nonzero::{NonZeroU128, NonZeroU16, NonZeroU32, NonZeroU64, NonZeroU8, NonZeroUsize};
@@ -482,7 +484,7 @@ impl u8 {
Self = u8,
ActualT = u8,
SignedT = i8,
- NonZeroT = NonZeroU8,
+ NonZeroT = NonZero<u8>,
BITS = 8,
MAX = 255,
rot = 2,
@@ -1097,7 +1099,7 @@ impl u16 {
Self = u16,
ActualT = u16,
SignedT = i16,
- NonZeroT = NonZeroU16,
+ NonZeroT = NonZero<u16>,
BITS = 16,
MAX = 65535,
rot = 4,
@@ -1146,7 +1148,7 @@ impl u32 {
Self = u32,
ActualT = u32,
SignedT = i32,
- NonZeroT = NonZeroU32,
+ NonZeroT = NonZero<u32>,
BITS = 32,
MAX = 4294967295,
rot = 8,
@@ -1170,7 +1172,7 @@ impl u64 {
Self = u64,
ActualT = u64,
SignedT = i64,
- NonZeroT = NonZeroU64,
+ NonZeroT = NonZero<u64>,
BITS = 64,
MAX = 18446744073709551615,
rot = 12,
@@ -1194,7 +1196,7 @@ impl u128 {
Self = u128,
ActualT = u128,
SignedT = i128,
- NonZeroT = NonZeroU128,
+ NonZeroT = NonZero<u128>,
BITS = 128,
MAX = 340282366920938463463374607431768211455,
rot = 16,
@@ -1220,7 +1222,7 @@ impl usize {
Self = usize,
ActualT = u16,
SignedT = isize,
- NonZeroT = NonZeroUsize,
+ NonZeroT = NonZero<usize>,
BITS = 16,
MAX = 65535,
rot = 4,
@@ -1245,7 +1247,7 @@ impl usize {
Self = usize,
ActualT = u32,
SignedT = isize,
- NonZeroT = NonZeroUsize,
+ NonZeroT = NonZero<usize>,
BITS = 32,
MAX = 4294967295,
rot = 8,
@@ -1270,7 +1272,7 @@ impl usize {
Self = usize,
ActualT = u64,
SignedT = isize,
- NonZeroT = NonZeroUsize,
+ NonZeroT = NonZero<usize>,
BITS = 64,
MAX = 18446744073709551615,
rot = 12,
diff --git a/library/core/src/num/nonzero.rs b/library/core/src/num/nonzero.rs
index 2df38ab5848af..715c3a0b8ac34 100644
--- a/library/core/src/num/nonzero.rs
+++ b/library/core/src/num/nonzero.rs
@@ -8,6 +8,69 @@ use super::from_str_radix;
use super::{IntErrorKind, ParseIntError};
use crate::intrinsics;
+mod private {
+ #[unstable(
+ feature = "nonzero_internals",
+ reason = "implementation detail which may disappear or be replaced at any time",
+ issue = "none"
+ )]
+ #[const_trait]
+ pub trait Sealed {}
+}
+
+/// A marker trait for primitive types which can be zero.
+///
+/// This is an implementation detail for [`NonZero<T>`](NonZero) which may disappear or be replaced at any time.
+#[unstable(
+ feature = "nonzero_internals",
+ reason = "implementation detail which may disappear or be replaced at any time",
+ issue = "none"
+)]
+#[const_trait]
+pub trait ZeroablePrimitive: Sized + Copy + private::Sealed {
+ type NonZero;
+}
+
+#[unstable(
+ feature = "nonzero_internals",
+ reason = "implementation detail which may disappear or be replaced at any time",
+ issue = "none"
+)]
+pub(crate) type NonZero<T> = <T as ZeroablePrimitive>::NonZero;
+
+macro_rules! impl_zeroable_primitive {
+ ($NonZero:ident ( $primitive:ty )) => {
+ #[unstable(
+ feature = "nonzero_internals",
+ reason = "implementation detail which may disappear or be replaced at any time",
+ issue = "none"
+ )]
+ impl const private::Sealed for $primitive {}
+
+ #[unstable(
+ feature = "nonzero_internals",
+ reason = "implementation detail which may disappear or be replaced at any time",
+ issue = "none"
+ )]
+ impl const ZeroablePrimitive for $primitive {
+ type NonZero = $NonZero;
+ }
+ };
+}
+
+impl_zeroable_primitive!(NonZeroU8(u8));
+impl_zeroable_primitive!(NonZeroU16(u16));
+impl_zeroable_primitive!(NonZeroU32(u32));
+impl_zeroable_primitive!(NonZeroU64(u64));
+impl_zeroable_primitive!(NonZeroU128(u128));
+impl_zeroable_primitive!(NonZeroUsize(usize));
+impl_zeroable_primitive!(NonZeroI8(i8));
+impl_zeroable_primitive!(NonZeroI16(i16));
+impl_zeroable_primitive!(NonZeroI32(i32));
+impl_zeroable_primitive!(NonZeroI64(i64));
+impl_zeroable_primitive!(NonZeroI128(i128));
+impl_zeroable_primitive!(NonZeroIsize(isize));
+
macro_rules! impl_nonzero_fmt {
( #[$stability: meta] ( $( $Trait: ident ),+ ) for $Ty: ident ) => {
$(
diff --git a/library/core/src/num/uint_macros.rs b/library/core/src/num/uint_macros.rs
index 11a53aaf122ec..bbbbd61c4b1c9 100644
--- a/library/core/src/num/uint_macros.rs
+++ b/library/core/src/num/uint_macros.rs
@@ -3,7 +3,7 @@ macro_rules! uint_impl {
Self = $SelfT:ty,
ActualT = $ActualT:ident,
SignedT = $SignedT:ident,
- NonZeroT = $NonZeroT:ident,
+ NonZeroT = $NonZeroT:ty,
// There are all for use *only* in doc comments.
// As such, they're all passed as literals -- passing them as a string
@@ -842,6 +842,7 @@ macro_rules! uint_impl {
without modifying the original"]
#[inline]
pub const fn checked_ilog2(self) -> Option<u32> {
+ // FIXME: Simply use `NonZero::new` once it is actually generic.
if let Some(x) = <$NonZeroT>::new(self) {
Some(x.ilog2())
} else {
@@ -864,6 +865,7 @@ macro_rules! uint_impl {
without modifying the original"]
#[inline]
pub const fn checked_ilog10(self) -> Option<u32> {
+ // FIXME: Simply use `NonZero::new` once it is actually generic.
if let Some(x) = <$NonZeroT>::new(self) {
Some(x.ilog10())
} else {
diff --git a/library/core/src/slice/iter.rs b/library/core/src/slice/iter.rs
index 3d58afd26eacc..4a64faf9b3f2a 100644
--- a/library/core/src/slice/iter.rs
+++ b/library/core/src/slice/iter.rs
@@ -12,7 +12,7 @@ use crate::iter::{
};
use crate::marker::PhantomData;
use crate::mem::{self, SizedTypeProperties};
-use crate::num::NonZeroUsize;
+use crate::num::{NonZero, NonZeroUsize};
use crate::ptr::{self, invalid, invalid_mut, NonNull};
use super::{from_raw_parts, from_raw_parts_mut};
@@ -1305,12 +1305,12 @@ forward_iterator! { RSplitNMut: T, &'a mut [T] }
#[must_use = "iterators are lazy and do nothing unless consumed"]
pub struct Windows<'a, T: 'a> {
v: &'a [T],
- size: NonZeroUsize,
+ size: NonZero<usize>,
}
impl<'a, T: 'a> Windows<'a, T> {
#[inline]
- pub(super) fn new(slice: &'a [T], size: NonZeroUsize) -> Self {
+ pub(super) fn new(slice: &'a [T], size: NonZero<usize>) -> Self {
Self { v: slice, size }
}
}