Add 12 num::NonZero* types for each primitive integer
RFC: https://github.com/rust-lang/rfcs/pull/2307
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@ -62,7 +62,7 @@ impl_zeroable_for_integer_types! {
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/// NULL or 0 that might allow certain optimizations.
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#[lang = "non_zero"]
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#[derive(Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Debug, Hash)]
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pub struct NonZero<T: Zeroable>(T);
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pub struct NonZero<T: Zeroable>(pub(crate) T);
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impl<T: Zeroable> NonZero<T> {
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/// Creates an instance of NonZero with the provided value.
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@ -15,9 +15,96 @@
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use convert::{Infallible, TryFrom};
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use fmt;
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use intrinsics;
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use nonzero::NonZero;
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use ops;
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use str::FromStr;
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macro_rules! impl_nonzero_fmt {
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( #[$stability: meta] ( $( $Trait: ident ),+ ) for $Ty: ident ) => {
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$(
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#[$stability]
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impl fmt::$Trait for $Ty {
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#[inline]
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fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
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self.get().fmt(f)
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}
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}
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)+
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}
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}
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macro_rules! nonzero_integers {
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( #[$stability: meta] $( $Ty: ident($Int: ty); )+ ) => {
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$(
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/// An integer that is known not to equal zero.
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///
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/// This may enable some memory layout optimization such as:
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///
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/// ```rust
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/// # #![feature(nonzero)]
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/// use std::mem::size_of;
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/// assert_eq!(size_of::<Option<std::num::NonZeroU32>>(), size_of::<u32>());
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/// ```
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#[$stability]
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#[derive(Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Hash)]
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pub struct $Ty(NonZero<$Int>);
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impl $Ty {
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/// Create a non-zero without checking the value.
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///
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/// # Safety
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///
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/// The value must not be zero.
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#[$stability]
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#[inline]
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pub const unsafe fn new_unchecked(n: $Int) -> Self {
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$Ty(NonZero(n))
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}
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/// Create a non-zero if the given value is not zero.
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#[$stability]
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#[inline]
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pub fn new(n: $Int) -> Option<Self> {
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if n != 0 {
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Some($Ty(NonZero(n)))
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} else {
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None
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}
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}
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/// Returns the value as a primitive type.
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#[$stability]
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#[inline]
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pub fn get(self) -> $Int {
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self.0 .0
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}
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}
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impl_nonzero_fmt! {
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#[$stability]
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(Debug, Display, Binary, Octal, LowerHex, UpperHex) for $Ty
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}
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)+
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}
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}
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nonzero_integers! {
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#[unstable(feature = "nonzero", issue = "27730")]
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NonZeroU8(u8); NonZeroI8(i8);
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NonZeroU16(u16); NonZeroI16(i16);
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NonZeroU32(u32); NonZeroI32(i32);
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NonZeroU64(u64); NonZeroI64(i64);
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NonZeroUsize(usize); NonZeroIsize(isize);
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}
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nonzero_integers! {
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// Change this to `#[unstable(feature = "i128", issue = "35118")]`
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// if other NonZero* integer types are stabilizied before 128-bit integers
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#[unstable(feature = "nonzero", issue = "27730")]
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NonZeroU128(u128); NonZeroI128(i128);
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}
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/// Provides intentionally-wrapped arithmetic on `T`.
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///
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/// Operations like `+` on `u32` values is intended to never overflow,
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@ -282,6 +282,7 @@
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#![feature(macro_vis_matcher)]
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#![feature(needs_panic_runtime)]
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#![feature(exhaustive_patterns)]
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#![feature(nonzero)]
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#![feature(num_bits_bytes)]
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#![feature(old_wrapping)]
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#![feature(on_unimplemented)]
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@ -21,6 +21,17 @@ pub use core::num::{FpCategory, ParseIntError, ParseFloatError, TryFromIntError}
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#[stable(feature = "rust1", since = "1.0.0")]
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pub use core::num::Wrapping;
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#[unstable(feature = "nonzero", issue = "27730")]
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pub use core::num::{
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NonZeroU8, NonZeroI8, NonZeroU16, NonZeroI16, NonZeroU32, NonZeroI32,
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NonZeroU64, NonZeroI64, NonZeroUsize, NonZeroIsize,
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};
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// Change this to `#[unstable(feature = "i128", issue = "35118")]`
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// if other NonZero* integer types are stabilizied before 128-bit integers
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#[unstable(feature = "nonzero", issue = "27730")]
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pub use core::num::{NonZeroU128, NonZeroI128};
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#[cfg(test)] use fmt;
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#[cfg(test)] use ops::{Add, Sub, Mul, Div, Rem};
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