Add private NonZero<T> type alias.

library/core/src/convert/num.rs

@@ -1,6 +1,7 @@
-use super::{From, TryFrom};
 use crate::num::TryFromIntError;
 
+use super::{From, TryFrom};
+
 mod private {
     /// This trait being unreachable from outside the crate
     /// prevents other implementations of the `FloatToInt` trait,

library/core/src/ffi/mod.rs

@@ -59,10 +59,10 @@ type_alias! { "c_char.md", c_char = c_char_definition::c_char, NonZero_c_char =
 #[cfg(all())]
 #[doc(cfg(all()))] }
 
-type_alias! { "c_schar.md", c_schar = i8, NonZero_c_schar = NonZeroI8; }
-type_alias! { "c_uchar.md", c_uchar = u8, NonZero_c_uchar = NonZeroU8; }
-type_alias! { "c_short.md", c_short = i16, NonZero_c_short = NonZeroI16; }
-type_alias! { "c_ushort.md", c_ushort = u16, NonZero_c_ushort = NonZeroU16; }
+type_alias! { "c_schar.md", c_schar = i8, NonZero_c_schar = NonZero<i8>; }
+type_alias! { "c_uchar.md", c_uchar = u8, NonZero_c_uchar = NonZero<u8>; }
+type_alias! { "c_short.md", c_short = i16, NonZero_c_short = NonZero<i16>; }
+type_alias! { "c_ushort.md", c_ushort = u16, NonZero_c_ushort = NonZero<u16>; }
 
 type_alias! { "c_int.md", c_int = c_int_definition::c_int, NonZero_c_int = c_int_definition::NonZero_c_int;
 #[doc(cfg(all()))] }
@@ -74,8 +74,8 @@ type_alias! { "c_long.md", c_long = c_long_definition::c_long, NonZero_c_long =
 type_alias! { "c_ulong.md", c_ulong = c_long_definition::c_ulong, NonZero_c_ulong = c_long_definition::NonZero_c_ulong;
 #[doc(cfg(all()))] }
 
-type_alias! { "c_longlong.md", c_longlong = i64, NonZero_c_longlong = NonZeroI64; }
-type_alias! { "c_ulonglong.md", c_ulonglong = u64, NonZero_c_ulonglong = NonZeroU64; }
+type_alias! { "c_longlong.md", c_longlong = i64, NonZero_c_longlong = NonZero<i64>; }
+type_alias! { "c_ulonglong.md", c_ulonglong = u64, NonZero_c_ulonglong = NonZero<u64>; }
 
 type_alias_no_nz! { "c_float.md", c_float = f32; }
 type_alias_no_nz! { "c_double.md", c_double = f64; }
@@ -147,11 +147,11 @@ mod c_char_definition {
             target_os = "horizon"
         ))] {
             pub type c_char = u8;
-            pub type NonZero_c_char = crate::num::NonZeroU8;
+            pub type NonZero_c_char = crate::num::NonZero<u8>;
         } else {
             // On every other target, c_char is signed.
             pub type c_char = i8;
-            pub type NonZero_c_char = crate::num::NonZeroI8;
+            pub type NonZero_c_char = crate::num::NonZero<i8>;
         }
     }
 }
@@ -160,14 +160,14 @@ mod c_int_definition {
     cfg_if! {
         if #[cfg(any(target_arch = "avr", target_arch = "msp430"))] {
             pub type c_int = i16;
-            pub type NonZero_c_int = crate::num::NonZeroI16;
+            pub type NonZero_c_int = crate::num::NonZero<i16>;
             pub type c_uint = u16;
-            pub type NonZero_c_uint = crate::num::NonZeroU16;
+            pub type NonZero_c_uint = crate::num::NonZero<u16>;
         } else {
             pub type c_int = i32;
-            pub type NonZero_c_int = crate::num::NonZeroI32;
+            pub type NonZero_c_int = crate::num::NonZero<i32>;
             pub type c_uint = u32;
-            pub type NonZero_c_uint = crate::num::NonZeroU32;
+            pub type NonZero_c_uint = crate::num::NonZero<u32>;
         }
     }
 }
@@ -176,15 +176,15 @@ mod c_long_definition {
     cfg_if! {
         if #[cfg(all(target_pointer_width = "64", not(windows)))] {
             pub type c_long = i64;
-            pub type NonZero_c_long = crate::num::NonZeroI64;
+            pub type NonZero_c_long = crate::num::NonZero<i64>;
             pub type c_ulong = u64;
-            pub type NonZero_c_ulong = crate::num::NonZeroU64;
+            pub type NonZero_c_ulong = crate::num::NonZero<u64>;
         } else {
             // The minimal size of `long` in the C standard is 32 bits
             pub type c_long = i32;
-            pub type NonZero_c_long = crate::num::NonZeroI32;
+            pub type NonZero_c_long = crate::num::NonZero<i32>;
             pub type c_ulong = u32;
-            pub type NonZero_c_ulong = crate::num::NonZeroU32;
+            pub type NonZero_c_ulong = crate::num::NonZero<u32>;
         }
     }
 }

library/core/src/num/mod.rs

@@ -70,6 +70,8 @@ impl Error for 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};
 
@@ -299,7 +301,7 @@ impl isize {
 const ASCII_CASE_MASK: u8 = 0b0010_0000;
 
 impl u8 {
-    uint_impl! { u8, u8, i8, NonZeroU8, 8, 255, 2, "0x82", "0xa", "0x12", "0x12", "0x48", "[0x12]",
+    uint_impl! { u8, u8, i8, NonZero<u8>, 8, 255, 2, "0x82", "0xa", "0x12", "0x12", "0x48", "[0x12]",
     "[0x12]", "", "", "" }
     widening_impl! { u8, u16, 8, unsigned }
 
@@ -884,7 +886,7 @@ impl u8 {
 }
 
 impl u16 {
-    uint_impl! { u16, u16, i16, NonZeroU16, 16, 65535, 4, "0xa003", "0x3a", "0x1234", "0x3412", "0x2c48",
+    uint_impl! { u16, u16, i16, NonZero<u16>, 16, 65535, 4, "0xa003", "0x3a", "0x1234", "0x3412", "0x2c48",
     "[0x34, 0x12]", "[0x12, 0x34]", "", "", "" }
     widening_impl! { u16, u32, 16, unsigned }
 
@@ -915,13 +917,13 @@ impl u16 {
 }
 
 impl u32 {
-    uint_impl! { u32, u32, i32, NonZeroU32, 32, 4294967295, 8, "0x10000b3", "0xb301", "0x12345678",
+    uint_impl! { u32, u32, i32, NonZero<u32>, 32, 4294967295, 8, "0x10000b3", "0xb301", "0x12345678",
     "0x78563412", "0x1e6a2c48", "[0x78, 0x56, 0x34, 0x12]", "[0x12, 0x34, 0x56, 0x78]", "", "", "" }
     widening_impl! { u32, u64, 32, unsigned }
 }
 
 impl u64 {
-    uint_impl! { u64, u64, i64, NonZeroU64, 64, 18446744073709551615, 12, "0xaa00000000006e1", "0x6e10aa",
+    uint_impl! { u64, u64, i64, NonZero<u64>, 64, 18446744073709551615, 12, "0xaa00000000006e1", "0x6e10aa",
     "0x1234567890123456", "0x5634129078563412", "0x6a2c48091e6a2c48",
     "[0x56, 0x34, 0x12, 0x90, 0x78, 0x56, 0x34, 0x12]",
     "[0x12, 0x34, 0x56, 0x78, 0x90, 0x12, 0x34, 0x56]",
@@ -930,7 +932,7 @@ impl u64 {
 }
 
 impl u128 {
-    uint_impl! { u128, u128, i128, NonZeroU128, 128, 340282366920938463463374607431768211455, 16,
+    uint_impl! { u128, u128, i128, NonZero<u128>, 128, 340282366920938463463374607431768211455, 16,
     "0x13f40000000000000000000000004f76", "0x4f7613f4", "0x12345678901234567890123456789012",
     "0x12907856341290785634129078563412", "0x48091e6a2c48091e6a2c48091e6a2c48",
     "[0x12, 0x90, 0x78, 0x56, 0x34, 0x12, 0x90, 0x78, \
@@ -942,15 +944,15 @@ impl u128 {
 
 #[cfg(target_pointer_width = "16")]
 impl usize {
-    uint_impl! { usize, u16, isize, NonZeroUsize, 16, 65535, 4, "0xa003", "0x3a", "0x1234", "0x3412", "0x2c48",
+    uint_impl! { usize, u16, isize, NonZero<usize>, 16, 65535, 4, "0xa003", "0x3a", "0x1234", "0x3412", "0x2c48",
     "[0x34, 0x12]", "[0x12, 0x34]",
     usize_isize_to_xe_bytes_doc!(), usize_isize_from_xe_bytes_doc!(),
     " on 16-bit targets" }
     widening_impl! { usize, u32, 16, unsigned }
 }
 #[cfg(target_pointer_width = "32")]
 impl usize {
-    uint_impl! { usize, u32, isize, NonZeroUsize, 32, 4294967295, 8, "0x10000b3", "0xb301", "0x12345678",
+    uint_impl! { usize, u32, isize, NonZero<usize>, 32, 4294967295, 8, "0x10000b3", "0xb301", "0x12345678",
     "0x78563412", "0x1e6a2c48", "[0x78, 0x56, 0x34, 0x12]", "[0x12, 0x34, 0x56, 0x78]",
     usize_isize_to_xe_bytes_doc!(), usize_isize_from_xe_bytes_doc!(),
     " on 32-bit targets" }
@@ -959,7 +961,7 @@ impl usize {
 
 #[cfg(target_pointer_width = "64")]
 impl usize {
-    uint_impl! { usize, u64, isize, NonZeroUsize, 64, 18446744073709551615, 12, "0xaa00000000006e1", "0x6e10aa",
+    uint_impl! { usize, u64, isize, NonZero<usize>, 64, 18446744073709551615, 12, "0xaa00000000006e1", "0x6e10aa",
     "0x1234567890123456", "0x5634129078563412", "0x6a2c48091e6a2c48",
     "[0x56, 0x34, 0x12, 0x90, 0x78, 0x56, 0x34, 0x12]",
     "[0x12, 0x34, 0x56, 0x78, 0x90, 0x12, 0x34, 0x56]",

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 ) => {
         $(

library/core/src/num/uint_macros.rs

@@ -1,5 +1,5 @@
 macro_rules! uint_impl {
-    ($SelfT:ty, $ActualT:ident, $SignedT:ident, $NonZeroT:ident,
+    ($SelfT:ty, $ActualT:ident, $SignedT:ident, $NonZeroT:ty,
         $BITS:expr, $MaxV:expr,
         $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
         $reversed:expr, $le_bytes:expr, $be_bytes:expr,
@@ -808,6 +808,7 @@ macro_rules! uint_impl {
                       without modifying the original"]
         #[inline]
         pub const fn checked_ilog2(self) -> Option<u32> {
+            // FIXME: Simply use `NonZero::new` once it is actually generic.
             if let Some(x) = <$NonZeroT>::new(self) {
                 Some(x.ilog2())
             } else {
@@ -830,6 +831,7 @@ 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 {

library/core/src/slice/iter.rs

@@ -10,7 +10,7 @@ use crate::intrinsics::{assume, exact_div, unchecked_sub};
 use crate::iter::{FusedIterator, TrustedLen, TrustedRandomAccess, TrustedRandomAccessNoCoerce};
 use crate::marker::{PhantomData, Send, Sized, Sync};
 use crate::mem::{self, SizedTypeProperties};
-use crate::num::NonZeroUsize;
+use crate::num::NonZero;
 use crate::ptr::NonNull;
 
 use super::{from_raw_parts, from_raw_parts_mut};
@@ -1297,12 +1297,12 @@ 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 }
     }
 }