Rollup merge of #50808 - SimonSapin:nonzero, r=alexcrichton

Stabilize num::NonZeroU*

Tracking issue: https://github.com/rust-lang/rust/issues/49137

5 files changed, 14 insertions, 132 deletions

diff --git a/src/libcore/lib.rs b/src/libcore/lib.rs
index 54f35d17974..06fbfcecba8 100644
--- a/src/libcore/lib.rs
+++ b/src/libcore/lib.rs
@@ -171,7 +171,6 @@ pub mod prelude;
 
 pub mod intrinsics;
 pub mod mem;
-pub mod nonzero;
 pub mod ptr;
 pub mod hint;
 
@@ -221,6 +220,7 @@ pub mod heap {
 
 // note: does not need to be public
 mod iter_private;
+mod nonzero;
 mod tuple;
 mod unit;
 
diff --git a/src/libcore/nonzero.rs b/src/libcore/nonzero.rs
index 19836d98844..ee5230cef8d 100644
--- a/src/libcore/nonzero.rs
+++ b/src/libcore/nonzero.rs
@@ -9,103 +9,13 @@
 // except according to those terms.
 
 //! Exposes the NonZero lang item which provides optimization hints.
-#![unstable(feature = "nonzero", reason = "deprecated", issue = "49137")]
-#![rustc_deprecated(reason = "use `std::ptr::NonNull` or `std::num::NonZero*` instead",
-                    since = "1.26.0")]
-#![allow(deprecated)]
 
 use ops::CoerceUnsized;
 
-/// Unsafe trait to indicate what types are usable with the NonZero struct
-pub unsafe trait Zeroable {
-    /// Whether this value is zero
-    fn is_zero(&self) -> bool;
-}
-
-macro_rules! impl_zeroable_for_pointer_types {
-    ( $( $Ptr: ty )+ ) => {
-        $(
-            /// For fat pointers to be considered "zero", only the "data" part needs to be null.
-            unsafe impl<T: ?Sized> Zeroable for $Ptr {
-                #[inline]
-                fn is_zero(&self) -> bool {
-                    (*self).is_null()
-                }
-            }
-        )+
-    }
-}
-
-macro_rules! impl_zeroable_for_integer_types {
-    ( $( $Int: ty )+ ) => {
-        $(
-            unsafe impl Zeroable for $Int {
-                #[inline]
-                fn is_zero(&self) -> bool {
-                    *self == 0
-                }
-            }
-        )+
-    }
-}
-
-impl_zeroable_for_pointer_types! {
-    *const T
-    *mut T
-}
-
-impl_zeroable_for_integer_types! {
-    usize u8 u16 u32 u64 u128
-    isize i8 i16 i32 i64 i128
-}
-
 /// A wrapper type for raw pointers and integers that will never be
 /// NULL or 0 that might allow certain optimizations.
 #[lang = "non_zero"]
-#[derive(Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Debug, Hash)]
-pub struct NonZero<T: Zeroable>(pub(crate) T);
-
-impl<T: Zeroable> NonZero<T> {
-    /// Creates an instance of NonZero with the provided value.
-    /// You must indeed ensure that the value is actually "non-zero".
-    #[inline]
-    pub const unsafe fn new_unchecked(inner: T) -> Self {
-        NonZero(inner)
-    }
-
-    /// Creates an instance of NonZero with the provided value.
-    #[inline]
-    pub fn new(inner: T) -> Option<Self> {
-        if inner.is_zero() {
-            None
-        } else {
-            Some(NonZero(inner))
-        }
-    }
-
-    /// Gets the inner value.
-    pub fn get(self) -> T {
-        self.0
-    }
-}
-
-impl<T: Zeroable+CoerceUnsized<U>, U: Zeroable> CoerceUnsized<NonZero<U>> for NonZero<T> {}
-
-impl<'a, T: ?Sized> From<&'a mut T> for NonZero<*mut T> {
-    fn from(reference: &'a mut T) -> Self {
-        NonZero(reference)
-    }
-}
-
-impl<'a, T: ?Sized> From<&'a mut T> for NonZero<*const T> {
-    fn from(reference: &'a mut T) -> Self {
-        let ptr: *mut T = reference;
-        NonZero(ptr)
-    }
-}
+#[derive(Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Hash)]
+pub(crate) struct NonZero<T>(pub(crate) T);
 
-impl<'a, T: ?Sized> From<&'a T> for NonZero<*const T> {
-    fn from(reference: &'a T) -> Self {
-        NonZero(reference)
-    }
-}
+impl<T: CoerceUnsized<U>, U> CoerceUnsized<NonZero<U>> for NonZero<T> {}
diff --git a/src/libcore/num/mod.rs b/src/libcore/num/mod.rs
index a1168d74e4b..6df8ca98ba9 100644
--- a/src/libcore/num/mod.rs
+++ b/src/libcore/num/mod.rs
@@ -16,15 +16,14 @@ use convert::TryFrom;
 use fmt;
 use intrinsics;
 use mem;
-#[allow(deprecated)] use nonzero::NonZero;
+use nonzero::NonZero;
 use ops;
 use str::FromStr;
 
 macro_rules! impl_nonzero_fmt {
-    ( #[$stability: meta] ( $( $Trait: ident ),+ ) for $Ty: ident ) => {
+    ( ( $( $Trait: ident ),+ ) for $Ty: ident ) => {
         $(
-            #[$stability]
-            #[allow(deprecated)]
+            #[stable(feature = "nonzero", since = "1.28.0")]
             impl fmt::$Trait for $Ty {
                 #[inline]
                 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
@@ -36,7 +35,7 @@ macro_rules! impl_nonzero_fmt {
 }
 
 macro_rules! nonzero_integers {
-    ( #[$stability: meta] #[$deprecation: meta] $( $Ty: ident($Int: ty); )+ ) => {
+    ( $( $Ty: ident($Int: ty); )+ ) => {
         $(
             /// An integer that is known not to equal zero.
             ///
@@ -47,27 +46,24 @@ macro_rules! nonzero_integers {
             /// use std::mem::size_of;
             /// assert_eq!(size_of::<Option<std::num::NonZeroU32>>(), size_of::<u32>());
             /// ```
-            #[$stability]
-            #[$deprecation]
-            #[allow(deprecated)]
+            #[stable(feature = "nonzero", since = "1.28.0")]
             #[derive(Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Hash)]
             pub struct $Ty(NonZero<$Int>);
 
-            #[allow(deprecated)]
             impl $Ty {
                 /// Create a non-zero without checking the value.
                 ///
                 /// # Safety
                 ///
                 /// The value must not be zero.
-                #[$stability]
+                #[stable(feature = "nonzero", since = "1.28.0")]
                 #[inline]
                 pub const unsafe fn new_unchecked(n: $Int) -> Self {
                     $Ty(NonZero(n))
                 }
 
                 /// Create a non-zero if the given value is not zero.
-                #[$stability]
+                #[stable(feature = "nonzero", since = "1.28.0")]
                 #[inline]
                 pub fn new(n: $Int) -> Option<Self> {
                     if n != 0 {
@@ -78,7 +74,7 @@ macro_rules! nonzero_integers {
                 }
 
                 /// Returns the value as a primitive type.
-                #[$stability]
+                #[stable(feature = "nonzero", since = "1.28.0")]
                 #[inline]
                 pub fn get(self) -> $Int {
                     self.0 .0
@@ -87,7 +83,6 @@ macro_rules! nonzero_integers {
             }
 
             impl_nonzero_fmt! {
-                #[$stability]
                 (Debug, Display, Binary, Octal, LowerHex, UpperHex) for $Ty
             }
         )+
@@ -95,8 +90,6 @@ macro_rules! nonzero_integers {
 }
 
 nonzero_integers! {
-    #[unstable(feature = "nonzero", issue = "49137")]
-    #[allow(deprecated)]  // Redundant, works around "error: inconsistent lockstep iteration"
     NonZeroU8(u8);
     NonZeroU16(u16);
     NonZeroU32(u32);
@@ -105,19 +98,6 @@ nonzero_integers! {
     NonZeroUsize(usize);
 }
 
-nonzero_integers! {
-    #[unstable(feature = "nonzero", issue = "49137")]
-    #[rustc_deprecated(since = "1.26.0", reason = "\
-        signed non-zero integers are considered for removal due to lack of known use cases. \
-        If you’re using them, please comment on https://github.com/rust-lang/rust/issues/49137")]
-    NonZeroI8(i8);
-    NonZeroI16(i16);
-    NonZeroI32(i32);
-    NonZeroI64(i64);
-    NonZeroI128(i128);
-    NonZeroIsize(isize);
-}
-
 /// Provides intentionally-wrapped arithmetic on `T`.
 ///
 /// Operations like `+` on `u32` values is intended to never overflow,
diff --git a/src/libcore/ptr.rs b/src/libcore/ptr.rs
index 83dfac7a3a2..63bcc024020 100644
--- a/src/libcore/ptr.rs
+++ b/src/libcore/ptr.rs
@@ -23,7 +23,7 @@ use fmt;
 use hash;
 use marker::{PhantomData, Unsize};
 use mem;
-#[allow(deprecated)] use nonzero::NonZero;
+use nonzero::NonZero;
 
 use cmp::Ordering::{self, Less, Equal, Greater};
 
@@ -2742,7 +2742,6 @@ impl<T: ?Sized> PartialOrd for *mut T {
 #[unstable(feature = "ptr_internals", issue = "0",
            reason = "use NonNull instead and consider PhantomData<T> \
                      (if you also use #[may_dangle]), Send, and/or Sync")]
-#[allow(deprecated)]
 #[doc(hidden)]
 pub struct Unique<T: ?Sized> {
     pointer: NonZero<*const T>,
@@ -2790,7 +2789,6 @@ impl<T: Sized> Unique<T> {
 }
 
 #[unstable(feature = "ptr_internals", issue = "0")]
-#[allow(deprecated)]
 impl<T: ?Sized> Unique<T> {
     /// Creates a new `Unique`.
     ///
@@ -2855,7 +2853,6 @@ impl<T: ?Sized> fmt::Pointer for Unique<T> {
 }
 
 #[unstable(feature = "ptr_internals", issue = "0")]
-#[allow(deprecated)]
 impl<'a, T: ?Sized> From<&'a mut T> for Unique<T> {
     fn from(reference: &'a mut T) -> Self {
         Unique { pointer: NonZero(reference as _), _marker: PhantomData }
@@ -2863,7 +2860,6 @@ impl<'a, T: ?Sized> From<&'a mut T> for Unique<T> {
 }
 
 #[unstable(feature = "ptr_internals", issue = "0")]
-#[allow(deprecated)]
 impl<'a, T: ?Sized> From<&'a T> for Unique<T> {
     fn from(reference: &'a T) -> Self {
         Unique { pointer: NonZero(reference as _), _marker: PhantomData }
@@ -2896,7 +2892,7 @@ impl<'a, T: ?Sized> From<NonNull<T>> for Unique<T> {
 /// provide a public API that follows the normal shared XOR mutable rules of Rust.
 #[stable(feature = "nonnull", since = "1.25.0")]
 pub struct NonNull<T: ?Sized> {
-    #[allow(deprecated)] pointer: NonZero<*const T>,
+    pointer: NonZero<*const T>,
 }
 
 /// `NonNull` pointers are not `Send` because the data they reference may be aliased.
@@ -2923,7 +2919,6 @@ impl<T: Sized> NonNull<T> {
     }
 }
 
-#[allow(deprecated)]
 impl<T: ?Sized> NonNull<T> {
     /// Creates a new `NonNull`.
     ///
@@ -3054,7 +3049,6 @@ impl<T: ?Sized> From<Unique<T>> for NonNull<T> {
 }
 
 #[stable(feature = "nonnull", since = "1.25.0")]
-#[allow(deprecated)]
 impl<'a, T: ?Sized> From<&'a mut T> for NonNull<T> {
     fn from(reference: &'a mut T) -> Self {
         NonNull { pointer: NonZero(reference as _) }
@@ -3062,7 +3056,6 @@ impl<'a, T: ?Sized> From<&'a mut T> for NonNull<T> {
 }
 
 #[stable(feature = "nonnull", since = "1.25.0")]
-#[allow(deprecated)]
 impl<'a, T: ?Sized> From<&'a T> for NonNull<T> {
     fn from(reference: &'a T) -> Self {
         NonNull { pointer: NonZero(reference as _) }
diff --git a/src/libcore/tests/lib.rs b/src/libcore/tests/lib.rs
index 5e98e40e0d5..7fb4b503c01 100644
--- a/src/libcore/tests/lib.rs
+++ b/src/libcore/tests/lib.rs
@@ -26,7 +26,6 @@
 #![feature(iterator_step_by)]
 #![feature(iterator_flatten)]
 #![feature(iterator_repeat_with)]
-#![feature(nonzero)]
 #![feature(pattern)]
 #![feature(range_is_empty)]
 #![feature(raw)]