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Diffstat (limited to 'library/core/src/num/wrapping.rs')
| -rw-r--r-- | library/core/src/num/wrapping.rs | 1123 |
1 files changed, 1123 insertions, 0 deletions
diff --git a/library/core/src/num/wrapping.rs b/library/core/src/num/wrapping.rs new file mode 100644 index 000000000..5353d900e --- /dev/null +++ b/library/core/src/num/wrapping.rs @@ -0,0 +1,1123 @@ +//! Definitions of `Wrapping<T>`. + +use crate::fmt; +use crate::ops::{Add, AddAssign, BitAnd, BitAndAssign, BitOr, BitOrAssign}; +use crate::ops::{BitXor, BitXorAssign, Div, DivAssign}; +use crate::ops::{Mul, MulAssign, Neg, Not, Rem, RemAssign}; +use crate::ops::{Shl, ShlAssign, Shr, ShrAssign, Sub, SubAssign}; + +/// Provides intentionally-wrapped arithmetic on `T`. +/// +/// Operations like `+` on `u32` values are intended to never overflow, +/// and in some debug configurations overflow is detected and results +/// in a panic. While most arithmetic falls into this category, some +/// code explicitly expects and relies upon modular arithmetic (e.g., +/// hashing). +/// +/// Wrapping arithmetic can be achieved either through methods like +/// `wrapping_add`, or through the `Wrapping<T>` type, which says that +/// all standard arithmetic operations on the underlying value are +/// intended to have wrapping semantics. +/// +/// The underlying value can be retrieved through the `.0` index of the +/// `Wrapping` tuple. +/// +/// # Examples +/// +/// ``` +/// use std::num::Wrapping; +/// +/// let zero = Wrapping(0u32); +/// let one = Wrapping(1u32); +/// +/// assert_eq!(u32::MAX, (zero - one).0); +/// ``` +/// +/// # Layout +/// +/// `Wrapping<T>` is guaranteed to have the same layout and ABI as `T`. +#[stable(feature = "rust1", since = "1.0.0")] +#[derive(PartialEq, Eq, PartialOrd, Ord, Clone, Copy, Default, Hash)] +#[repr(transparent)] +pub struct Wrapping<T>(#[stable(feature = "rust1", since = "1.0.0")] pub T); + +#[stable(feature = "rust1", since = "1.0.0")] +impl<T: fmt::Debug> fmt::Debug for Wrapping<T> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + self.0.fmt(f) + } +} + +#[stable(feature = "wrapping_display", since = "1.10.0")] +impl<T: fmt::Display> fmt::Display for Wrapping<T> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + self.0.fmt(f) + } +} + +#[stable(feature = "wrapping_fmt", since = "1.11.0")] +impl<T: fmt::Binary> fmt::Binary for Wrapping<T> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + self.0.fmt(f) + } +} + +#[stable(feature = "wrapping_fmt", since = "1.11.0")] +impl<T: fmt::Octal> fmt::Octal for Wrapping<T> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + self.0.fmt(f) + } +} + +#[stable(feature = "wrapping_fmt", since = "1.11.0")] +impl<T: fmt::LowerHex> fmt::LowerHex for Wrapping<T> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + self.0.fmt(f) + } +} + +#[stable(feature = "wrapping_fmt", since = "1.11.0")] +impl<T: fmt::UpperHex> fmt::UpperHex for Wrapping<T> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + self.0.fmt(f) + } +} + +#[allow(unused_macros)] +macro_rules! sh_impl_signed { + ($t:ident, $f:ident) => { + #[stable(feature = "rust1", since = "1.0.0")] + #[rustc_const_unstable(feature = "const_ops", issue = "90080")] + impl const Shl<$f> for Wrapping<$t> { + type Output = Wrapping<$t>; + + #[inline] + fn shl(self, other: $f) -> Wrapping<$t> { + if other < 0 { + Wrapping(self.0.wrapping_shr((-other & self::shift_max::$t as $f) as u32)) + } else { + Wrapping(self.0.wrapping_shl((other & self::shift_max::$t as $f) as u32)) + } + } + } + forward_ref_binop! { impl const Shl, shl for Wrapping<$t>, $f, + #[stable(feature = "wrapping_ref_ops", since = "1.39.0")] } + + #[stable(feature = "op_assign_traits", since = "1.8.0")] + #[rustc_const_unstable(feature = "const_ops", issue = "90080")] + impl const ShlAssign<$f> for Wrapping<$t> { + #[inline] + fn shl_assign(&mut self, other: $f) { + *self = *self << other; + } + } + forward_ref_op_assign! { impl const ShlAssign, shl_assign for Wrapping<$t>, $f } + + #[stable(feature = "rust1", since = "1.0.0")] + #[rustc_const_unstable(feature = "const_ops", issue = "90080")] + impl const Shr<$f> for Wrapping<$t> { + type Output = Wrapping<$t>; + + #[inline] + fn shr(self, other: $f) -> Wrapping<$t> { + if other < 0 { + Wrapping(self.0.wrapping_shl((-other & self::shift_max::$t as $f) as u32)) + } else { + Wrapping(self.0.wrapping_shr((other & self::shift_max::$t as $f) as u32)) + } + } + } + forward_ref_binop! { impl const Shr, shr for Wrapping<$t>, $f, + #[stable(feature = "wrapping_ref_ops", since = "1.39.0")] } + + #[stable(feature = "op_assign_traits", since = "1.8.0")] + #[rustc_const_unstable(feature = "const_ops", issue = "90080")] + impl const ShrAssign<$f> for Wrapping<$t> { + #[inline] + fn shr_assign(&mut self, other: $f) { + *self = *self >> other; + } + } + forward_ref_op_assign! { impl const ShrAssign, shr_assign for Wrapping<$t>, $f } + }; +} + +macro_rules! sh_impl_unsigned { + ($t:ident, $f:ident) => { + #[stable(feature = "rust1", since = "1.0.0")] + #[rustc_const_unstable(feature = "const_ops", issue = "90080")] + impl const Shl<$f> for Wrapping<$t> { + type Output = Wrapping<$t>; + + #[inline] + fn shl(self, other: $f) -> Wrapping<$t> { + Wrapping(self.0.wrapping_shl((other & self::shift_max::$t as $f) as u32)) + } + } + forward_ref_binop! { impl const Shl, shl for Wrapping<$t>, $f, + #[stable(feature = "wrapping_ref_ops", since = "1.39.0")] } + + #[stable(feature = "op_assign_traits", since = "1.8.0")] + #[rustc_const_unstable(feature = "const_ops", issue = "90080")] + impl const ShlAssign<$f> for Wrapping<$t> { + #[inline] + fn shl_assign(&mut self, other: $f) { + *self = *self << other; + } + } + forward_ref_op_assign! { impl const ShlAssign, shl_assign for Wrapping<$t>, $f } + + #[stable(feature = "rust1", since = "1.0.0")] + #[rustc_const_unstable(feature = "const_ops", issue = "90080")] + impl const Shr<$f> for Wrapping<$t> { + type Output = Wrapping<$t>; + + #[inline] + fn shr(self, other: $f) -> Wrapping<$t> { + Wrapping(self.0.wrapping_shr((other & self::shift_max::$t as $f) as u32)) + } + } + forward_ref_binop! { impl const Shr, shr for Wrapping<$t>, $f, + #[stable(feature = "wrapping_ref_ops", since = "1.39.0")] } + + #[stable(feature = "op_assign_traits", since = "1.8.0")] + #[rustc_const_unstable(feature = "const_ops", issue = "90080")] + impl const ShrAssign<$f> for Wrapping<$t> { + #[inline] + fn shr_assign(&mut self, other: $f) { + *self = *self >> other; + } + } + forward_ref_op_assign! { impl const ShrAssign, shr_assign for Wrapping<$t>, $f } + }; +} + +// FIXME (#23545): uncomment the remaining impls +macro_rules! sh_impl_all { + ($($t:ident)*) => ($( + //sh_impl_unsigned! { $t, u8 } + //sh_impl_unsigned! { $t, u16 } + //sh_impl_unsigned! { $t, u32 } + //sh_impl_unsigned! { $t, u64 } + //sh_impl_unsigned! { $t, u128 } + sh_impl_unsigned! { $t, usize } + + //sh_impl_signed! { $t, i8 } + //sh_impl_signed! { $t, i16 } + //sh_impl_signed! { $t, i32 } + //sh_impl_signed! { $t, i64 } + //sh_impl_signed! { $t, i128 } + //sh_impl_signed! { $t, isize } + )*) +} + +sh_impl_all! { u8 u16 u32 u64 u128 usize i8 i16 i32 i64 i128 isize } + +// FIXME(30524): impl Op<T> for Wrapping<T>, impl OpAssign<T> for Wrapping<T> +macro_rules! wrapping_impl { + ($($t:ty)*) => ($( + #[stable(feature = "rust1", since = "1.0.0")] + #[rustc_const_unstable(feature = "const_ops", issue = "90080")] + impl const Add for Wrapping<$t> { + type Output = Wrapping<$t>; + + #[inline] + fn add(self, other: Wrapping<$t>) -> Wrapping<$t> { + Wrapping(self.0.wrapping_add(other.0)) + } + } + forward_ref_binop! { impl const Add, add for Wrapping<$t>, Wrapping<$t>, + #[stable(feature = "wrapping_ref", since = "1.14.0")] } + + #[stable(feature = "op_assign_traits", since = "1.8.0")] + #[rustc_const_unstable(feature = "const_ops", issue = "90080")] + impl const AddAssign for Wrapping<$t> { + #[inline] + fn add_assign(&mut self, other: Wrapping<$t>) { + *self = *self + other; + } + } + forward_ref_op_assign! { impl const AddAssign, add_assign for Wrapping<$t>, Wrapping<$t> } + + #[stable(feature = "wrapping_int_assign_impl", since = "1.60.0")] + #[rustc_const_unstable(feature = "const_ops", issue = "90080")] + impl const AddAssign<$t> for Wrapping<$t> { + #[inline] + fn add_assign(&mut self, other: $t) { + *self = *self + Wrapping(other); + } + } + forward_ref_op_assign! { impl const AddAssign, add_assign for Wrapping<$t>, $t } + + #[stable(feature = "rust1", since = "1.0.0")] + #[rustc_const_unstable(feature = "const_ops", issue = "90080")] + impl const Sub for Wrapping<$t> { + type Output = Wrapping<$t>; + + #[inline] + fn sub(self, other: Wrapping<$t>) -> Wrapping<$t> { + Wrapping(self.0.wrapping_sub(other.0)) + } + } + forward_ref_binop! { impl const Sub, sub for Wrapping<$t>, Wrapping<$t>, + #[stable(feature = "wrapping_ref", since = "1.14.0")] } + + #[stable(feature = "op_assign_traits", since = "1.8.0")] + #[rustc_const_unstable(feature = "const_ops", issue = "90080")] + impl const SubAssign for Wrapping<$t> { + #[inline] + fn sub_assign(&mut self, other: Wrapping<$t>) { + *self = *self - other; + } + } + forward_ref_op_assign! { impl const SubAssign, sub_assign for Wrapping<$t>, Wrapping<$t> } + + #[stable(feature = "wrapping_int_assign_impl", since = "1.60.0")] + #[rustc_const_unstable(feature = "const_ops", issue = "90080")] + impl const SubAssign<$t> for Wrapping<$t> { + #[inline] + fn sub_assign(&mut self, other: $t) { + *self = *self - Wrapping(other); + } + } + forward_ref_op_assign! { impl const SubAssign, sub_assign for Wrapping<$t>, $t } + + #[stable(feature = "rust1", since = "1.0.0")] + #[rustc_const_unstable(feature = "const_ops", issue = "90080")] + impl const Mul for Wrapping<$t> { + type Output = Wrapping<$t>; + + #[inline] + fn mul(self, other: Wrapping<$t>) -> Wrapping<$t> { + Wrapping(self.0.wrapping_mul(other.0)) + } + } + forward_ref_binop! { impl Mul, mul for Wrapping<$t>, Wrapping<$t>, + #[stable(feature = "wrapping_ref", since = "1.14.0")] } + + #[stable(feature = "op_assign_traits", since = "1.8.0")] + #[rustc_const_unstable(feature = "const_ops", issue = "90080")] + impl const MulAssign for Wrapping<$t> { + #[inline] + fn mul_assign(&mut self, other: Wrapping<$t>) { + *self = *self * other; + } + } + forward_ref_op_assign! { impl const MulAssign, mul_assign for Wrapping<$t>, Wrapping<$t> } + + #[stable(feature = "wrapping_int_assign_impl", since = "1.60.0")] + #[rustc_const_unstable(feature = "const_ops", issue = "90080")] + impl const MulAssign<$t> for Wrapping<$t> { + #[inline] + fn mul_assign(&mut self, other: $t) { + *self = *self * Wrapping(other); + } + } + forward_ref_op_assign! { impl const MulAssign, mul_assign for Wrapping<$t>, $t } + + #[stable(feature = "wrapping_div", since = "1.3.0")] + #[rustc_const_unstable(feature = "const_ops", issue = "90080")] + impl const Div for Wrapping<$t> { + type Output = Wrapping<$t>; + + #[inline] + fn div(self, other: Wrapping<$t>) -> Wrapping<$t> { + Wrapping(self.0.wrapping_div(other.0)) + } + } + forward_ref_binop! { impl const Div, div for Wrapping<$t>, Wrapping<$t>, + #[stable(feature = "wrapping_ref", since = "1.14.0")] } + + #[stable(feature = "op_assign_traits", since = "1.8.0")] + #[rustc_const_unstable(feature = "const_ops", issue = "90080")] + impl const DivAssign for Wrapping<$t> { + #[inline] + fn div_assign(&mut self, other: Wrapping<$t>) { + *self = *self / other; + } + } + forward_ref_op_assign! { impl const DivAssign, div_assign for Wrapping<$t>, Wrapping<$t> } + + #[stable(feature = "wrapping_int_assign_impl", since = "1.60.0")] + #[rustc_const_unstable(feature = "const_ops", issue = "90080")] + impl const DivAssign<$t> for Wrapping<$t> { + #[inline] + fn div_assign(&mut self, other: $t) { + *self = *self / Wrapping(other); + } + } + forward_ref_op_assign! { impl const DivAssign, div_assign for Wrapping<$t>, $t } + + #[stable(feature = "wrapping_impls", since = "1.7.0")] + #[rustc_const_unstable(feature = "const_ops", issue = "90080")] + impl const Rem for Wrapping<$t> { + type Output = Wrapping<$t>; + + #[inline] + fn rem(self, other: Wrapping<$t>) -> Wrapping<$t> { + Wrapping(self.0.wrapping_rem(other.0)) + } + } + forward_ref_binop! { impl const Rem, rem for Wrapping<$t>, Wrapping<$t>, + #[stable(feature = "wrapping_ref", since = "1.14.0")] } + + #[stable(feature = "op_assign_traits", since = "1.8.0")] + #[rustc_const_unstable(feature = "const_ops", issue = "90080")] + impl const RemAssign for Wrapping<$t> { + #[inline] + fn rem_assign(&mut self, other: Wrapping<$t>) { + *self = *self % other; + } + } + forward_ref_op_assign! { impl const RemAssign, rem_assign for Wrapping<$t>, Wrapping<$t> } + + #[stable(feature = "wrapping_int_assign_impl", since = "1.60.0")] + #[rustc_const_unstable(feature = "const_ops", issue = "90080")] + impl const RemAssign<$t> for Wrapping<$t> { + #[inline] + fn rem_assign(&mut self, other: $t) { + *self = *self % Wrapping(other); + } + } + forward_ref_op_assign! { impl const RemAssign, rem_assign for Wrapping<$t>, $t } + + #[stable(feature = "rust1", since = "1.0.0")] + #[rustc_const_unstable(feature = "const_ops", issue = "90080")] + impl const Not for Wrapping<$t> { + type Output = Wrapping<$t>; + + #[inline] + fn not(self) -> Wrapping<$t> { + Wrapping(!self.0) + } + } + forward_ref_unop! { impl const Not, not for Wrapping<$t>, + #[stable(feature = "wrapping_ref", since = "1.14.0")] } + + #[stable(feature = "rust1", since = "1.0.0")] + #[rustc_const_unstable(feature = "const_ops", issue = "90080")] + impl const BitXor for Wrapping<$t> { + type Output = Wrapping<$t>; + + #[inline] + fn bitxor(self, other: Wrapping<$t>) -> Wrapping<$t> { + Wrapping(self.0 ^ other.0) + } + } + forward_ref_binop! { impl const BitXor, bitxor for Wrapping<$t>, Wrapping<$t>, + #[stable(feature = "wrapping_ref", since = "1.14.0")] } + + #[stable(feature = "op_assign_traits", since = "1.8.0")] + #[rustc_const_unstable(feature = "const_ops", issue = "90080")] + impl const BitXorAssign for Wrapping<$t> { + #[inline] + fn bitxor_assign(&mut self, other: Wrapping<$t>) { + *self = *self ^ other; + } + } + forward_ref_op_assign! { impl const BitXorAssign, bitxor_assign for Wrapping<$t>, Wrapping<$t> } + + #[stable(feature = "wrapping_int_assign_impl", since = "1.60.0")] + #[rustc_const_unstable(feature = "const_ops", issue = "90080")] + impl const BitXorAssign<$t> for Wrapping<$t> { + #[inline] + fn bitxor_assign(&mut self, other: $t) { + *self = *self ^ Wrapping(other); + } + } + forward_ref_op_assign! { impl const BitXorAssign, bitxor_assign for Wrapping<$t>, $t } + + #[stable(feature = "rust1", since = "1.0.0")] + #[rustc_const_unstable(feature = "const_ops", issue = "90080")] + impl const BitOr for Wrapping<$t> { + type Output = Wrapping<$t>; + + #[inline] + fn bitor(self, other: Wrapping<$t>) -> Wrapping<$t> { + Wrapping(self.0 | other.0) + } + } + forward_ref_binop! { impl const BitOr, bitor for Wrapping<$t>, Wrapping<$t>, + #[stable(feature = "wrapping_ref", since = "1.14.0")] } + + #[stable(feature = "op_assign_traits", since = "1.8.0")] + #[rustc_const_unstable(feature = "const_ops", issue = "90080")] + impl const BitOrAssign for Wrapping<$t> { + #[inline] + fn bitor_assign(&mut self, other: Wrapping<$t>) { + *self = *self | other; + } + } + forward_ref_op_assign! { impl const BitOrAssign, bitor_assign for Wrapping<$t>, Wrapping<$t> } + + #[stable(feature = "wrapping_int_assign_impl", since = "1.60.0")] + #[rustc_const_unstable(feature = "const_ops", issue = "90080")] + impl const BitOrAssign<$t> for Wrapping<$t> { + #[inline] + fn bitor_assign(&mut self, other: $t) { + *self = *self | Wrapping(other); + } + } + forward_ref_op_assign! { impl const BitOrAssign, bitor_assign for Wrapping<$t>, $t } + + #[stable(feature = "rust1", since = "1.0.0")] + #[rustc_const_unstable(feature = "const_ops", issue = "90080")] + impl const BitAnd for Wrapping<$t> { + type Output = Wrapping<$t>; + + #[inline] + fn bitand(self, other: Wrapping<$t>) -> Wrapping<$t> { + Wrapping(self.0 & other.0) + } + } + forward_ref_binop! { impl const BitAnd, bitand for Wrapping<$t>, Wrapping<$t>, + #[stable(feature = "wrapping_ref", since = "1.14.0")] } + + #[stable(feature = "op_assign_traits", since = "1.8.0")] + #[rustc_const_unstable(feature = "const_ops", issue = "90080")] + impl const BitAndAssign for Wrapping<$t> { + #[inline] + fn bitand_assign(&mut self, other: Wrapping<$t>) { + *self = *self & other; + } + } + forward_ref_op_assign! { impl const BitAndAssign, bitand_assign for Wrapping<$t>, Wrapping<$t> } + + #[stable(feature = "wrapping_int_assign_impl", since = "1.60.0")] + #[rustc_const_unstable(feature = "const_ops", issue = "90080")] + impl const BitAndAssign<$t> for Wrapping<$t> { + #[inline] + fn bitand_assign(&mut self, other: $t) { + *self = *self & Wrapping(other); + } + } + forward_ref_op_assign! { impl const BitAndAssign, bitand_assign for Wrapping<$t>, $t } + + #[stable(feature = "wrapping_neg", since = "1.10.0")] + #[rustc_const_unstable(feature = "const_ops", issue = "90080")] + impl const Neg for Wrapping<$t> { + type Output = Self; + #[inline] + fn neg(self) -> Self { + Wrapping(0) - self + } + } + forward_ref_unop! { impl const Neg, neg for Wrapping<$t>, + #[stable(feature = "wrapping_ref", since = "1.14.0")] } + + )*) +} + +wrapping_impl! { usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 } + +macro_rules! wrapping_int_impl { + ($($t:ty)*) => ($( + impl Wrapping<$t> { + /// Returns the smallest value that can be represented by this integer type. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + /// #![feature(wrapping_int_impl)] + /// use std::num::Wrapping; + /// + #[doc = concat!("assert_eq!(<Wrapping<", stringify!($t), ">>::MIN, Wrapping(", stringify!($t), "::MIN));")] + /// ``` + #[unstable(feature = "wrapping_int_impl", issue = "32463")] + pub const MIN: Self = Self(<$t>::MIN); + + /// Returns the largest value that can be represented by this integer type. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + /// #![feature(wrapping_int_impl)] + /// use std::num::Wrapping; + /// + #[doc = concat!("assert_eq!(<Wrapping<", stringify!($t), ">>::MAX, Wrapping(", stringify!($t), "::MAX));")] + /// ``` + #[unstable(feature = "wrapping_int_impl", issue = "32463")] + pub const MAX: Self = Self(<$t>::MAX); + + /// Returns the size of this integer type in bits. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + /// #![feature(wrapping_int_impl)] + /// use std::num::Wrapping; + /// + #[doc = concat!("assert_eq!(<Wrapping<", stringify!($t), ">>::BITS, ", stringify!($t), "::BITS);")] + /// ``` + #[unstable(feature = "wrapping_int_impl", issue = "32463")] + pub const BITS: u32 = <$t>::BITS; + + /// Returns the number of ones in the binary representation of `self`. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + /// #![feature(wrapping_int_impl)] + /// use std::num::Wrapping; + /// + #[doc = concat!("let n = Wrapping(0b01001100", stringify!($t), ");")] + /// + /// assert_eq!(n.count_ones(), 3); + /// ``` + #[inline] + #[doc(alias = "popcount")] + #[doc(alias = "popcnt")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[unstable(feature = "wrapping_int_impl", issue = "32463")] + pub const fn count_ones(self) -> u32 { + self.0.count_ones() + } + + /// Returns the number of zeros in the binary representation of `self`. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + /// #![feature(wrapping_int_impl)] + /// use std::num::Wrapping; + /// + #[doc = concat!("assert_eq!(Wrapping(!0", stringify!($t), ").count_zeros(), 0);")] + /// ``` + #[inline] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[unstable(feature = "wrapping_int_impl", issue = "32463")] + pub const fn count_zeros(self) -> u32 { + self.0.count_zeros() + } + + /// Returns the number of trailing zeros in the binary representation of `self`. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + /// #![feature(wrapping_int_impl)] + /// use std::num::Wrapping; + /// + #[doc = concat!("let n = Wrapping(0b0101000", stringify!($t), ");")] + /// + /// assert_eq!(n.trailing_zeros(), 3); + /// ``` + #[inline] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[unstable(feature = "wrapping_int_impl", issue = "32463")] + pub const fn trailing_zeros(self) -> u32 { + self.0.trailing_zeros() + } + + /// Shifts the bits to the left by a specified amount, `n`, + /// wrapping the truncated bits to the end of the resulting + /// integer. + /// + /// Please note this isn't the same operation as the `<<` shifting + /// operator! + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + /// #![feature(wrapping_int_impl)] + /// use std::num::Wrapping; + /// + /// let n: Wrapping<i64> = Wrapping(0x0123456789ABCDEF); + /// let m: Wrapping<i64> = Wrapping(-0x76543210FEDCBA99); + /// + /// assert_eq!(n.rotate_left(32), m); + /// ``` + #[inline] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[unstable(feature = "wrapping_int_impl", issue = "32463")] + pub const fn rotate_left(self, n: u32) -> Self { + Wrapping(self.0.rotate_left(n)) + } + + /// Shifts the bits to the right by a specified amount, `n`, + /// wrapping the truncated bits to the beginning of the resulting + /// integer. + /// + /// Please note this isn't the same operation as the `>>` shifting + /// operator! + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + /// #![feature(wrapping_int_impl)] + /// use std::num::Wrapping; + /// + /// let n: Wrapping<i64> = Wrapping(0x0123456789ABCDEF); + /// let m: Wrapping<i64> = Wrapping(-0xFEDCBA987654322); + /// + /// assert_eq!(n.rotate_right(4), m); + /// ``` + #[inline] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[unstable(feature = "wrapping_int_impl", issue = "32463")] + pub const fn rotate_right(self, n: u32) -> Self { + Wrapping(self.0.rotate_right(n)) + } + + /// Reverses the byte order of the integer. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + /// #![feature(wrapping_int_impl)] + /// use std::num::Wrapping; + /// + /// let n: Wrapping<i16> = Wrapping(0b0000000_01010101); + /// assert_eq!(n, Wrapping(85)); + /// + /// let m = n.swap_bytes(); + /// + /// assert_eq!(m, Wrapping(0b01010101_00000000)); + /// assert_eq!(m, Wrapping(21760)); + /// ``` + #[inline] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[unstable(feature = "wrapping_int_impl", issue = "32463")] + pub const fn swap_bytes(self) -> Self { + Wrapping(self.0.swap_bytes()) + } + + /// Reverses the bit pattern of the integer. + /// + /// # Examples + /// + /// Please note that this example is shared between integer types. + /// Which explains why `i16` is used here. + /// + /// Basic usage: + /// + /// ``` + /// use std::num::Wrapping; + /// + /// let n = Wrapping(0b0000000_01010101i16); + /// assert_eq!(n, Wrapping(85)); + /// + /// let m = n.reverse_bits(); + /// + /// assert_eq!(m.0 as u16, 0b10101010_00000000); + /// assert_eq!(m, Wrapping(-22016)); + /// ``` + #[stable(feature = "reverse_bits", since = "1.37.0")] + #[rustc_const_stable(feature = "const_reverse_bits", since = "1.37.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + pub const fn reverse_bits(self) -> Self { + Wrapping(self.0.reverse_bits()) + } + + /// Converts an integer from big endian to the target's endianness. + /// + /// On big endian this is a no-op. On little endian the bytes are + /// swapped. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + /// #![feature(wrapping_int_impl)] + /// use std::num::Wrapping; + /// + #[doc = concat!("let n = Wrapping(0x1A", stringify!($t), ");")] + /// + /// if cfg!(target_endian = "big") { + #[doc = concat!(" assert_eq!(<Wrapping<", stringify!($t), ">>::from_be(n), n)")] + /// } else { + #[doc = concat!(" assert_eq!(<Wrapping<", stringify!($t), ">>::from_be(n), n.swap_bytes())")] + /// } + /// ``` + #[inline] + #[must_use] + #[unstable(feature = "wrapping_int_impl", issue = "32463")] + pub const fn from_be(x: Self) -> Self { + Wrapping(<$t>::from_be(x.0)) + } + + /// Converts an integer from little endian to the target's endianness. + /// + /// On little endian this is a no-op. On big endian the bytes are + /// swapped. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + /// #![feature(wrapping_int_impl)] + /// use std::num::Wrapping; + /// + #[doc = concat!("let n = Wrapping(0x1A", stringify!($t), ");")] + /// + /// if cfg!(target_endian = "little") { + #[doc = concat!(" assert_eq!(<Wrapping<", stringify!($t), ">>::from_le(n), n)")] + /// } else { + #[doc = concat!(" assert_eq!(<Wrapping<", stringify!($t), ">>::from_le(n), n.swap_bytes())")] + /// } + /// ``` + #[inline] + #[must_use] + #[unstable(feature = "wrapping_int_impl", issue = "32463")] + pub const fn from_le(x: Self) -> Self { + Wrapping(<$t>::from_le(x.0)) + } + + /// Converts `self` to big endian from the target's endianness. + /// + /// On big endian this is a no-op. On little endian the bytes are + /// swapped. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + /// #![feature(wrapping_int_impl)] + /// use std::num::Wrapping; + /// + #[doc = concat!("let n = Wrapping(0x1A", stringify!($t), ");")] + /// + /// if cfg!(target_endian = "big") { + /// assert_eq!(n.to_be(), n) + /// } else { + /// assert_eq!(n.to_be(), n.swap_bytes()) + /// } + /// ``` + #[inline] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[unstable(feature = "wrapping_int_impl", issue = "32463")] + pub const fn to_be(self) -> Self { + Wrapping(self.0.to_be()) + } + + /// Converts `self` to little endian from the target's endianness. + /// + /// On little endian this is a no-op. On big endian the bytes are + /// swapped. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + /// #![feature(wrapping_int_impl)] + /// use std::num::Wrapping; + /// + #[doc = concat!("let n = Wrapping(0x1A", stringify!($t), ");")] + /// + /// if cfg!(target_endian = "little") { + /// assert_eq!(n.to_le(), n) + /// } else { + /// assert_eq!(n.to_le(), n.swap_bytes()) + /// } + /// ``` + #[inline] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[unstable(feature = "wrapping_int_impl", issue = "32463")] + pub const fn to_le(self) -> Self { + Wrapping(self.0.to_le()) + } + + /// Raises self to the power of `exp`, using exponentiation by squaring. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + /// #![feature(wrapping_int_impl)] + /// use std::num::Wrapping; + /// + #[doc = concat!("assert_eq!(Wrapping(3", stringify!($t), ").pow(4), Wrapping(81));")] + /// ``` + /// + /// Results that are too large are wrapped: + /// + /// ``` + /// #![feature(wrapping_int_impl)] + /// use std::num::Wrapping; + /// + /// assert_eq!(Wrapping(3i8).pow(5), Wrapping(-13)); + /// assert_eq!(Wrapping(3i8).pow(6), Wrapping(-39)); + /// ``` + #[inline] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[unstable(feature = "wrapping_int_impl", issue = "32463")] + pub fn pow(self, exp: u32) -> Self { + Wrapping(self.0.wrapping_pow(exp)) + } + } + )*) +} + +wrapping_int_impl! { usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 } + +macro_rules! wrapping_int_impl_signed { + ($($t:ty)*) => ($( + impl Wrapping<$t> { + /// Returns the number of leading zeros in the binary representation of `self`. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + /// #![feature(wrapping_int_impl)] + /// use std::num::Wrapping; + /// + #[doc = concat!("let n = Wrapping(", stringify!($t), "::MAX) >> 2;")] + /// + /// assert_eq!(n.leading_zeros(), 3); + /// ``` + #[inline] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[unstable(feature = "wrapping_int_impl", issue = "32463")] + pub const fn leading_zeros(self) -> u32 { + self.0.leading_zeros() + } + + /// Computes the absolute value of `self`, wrapping around at + /// the boundary of the type. + /// + /// The only case where such wrapping can occur is when one takes the absolute value of the negative + /// minimal value for the type this is a positive value that is too large to represent in the type. In + /// such a case, this function returns `MIN` itself. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + /// #![feature(wrapping_int_impl)] + /// use std::num::Wrapping; + /// + #[doc = concat!("assert_eq!(Wrapping(100", stringify!($t), ").abs(), Wrapping(100));")] + #[doc = concat!("assert_eq!(Wrapping(-100", stringify!($t), ").abs(), Wrapping(100));")] + #[doc = concat!("assert_eq!(Wrapping(", stringify!($t), "::MIN).abs(), Wrapping(", stringify!($t), "::MIN));")] + /// assert_eq!(Wrapping(-128i8).abs().0 as u8, 128u8); + /// ``` + #[inline] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[unstable(feature = "wrapping_int_impl", issue = "32463")] + pub fn abs(self) -> Wrapping<$t> { + Wrapping(self.0.wrapping_abs()) + } + + /// Returns a number representing sign of `self`. + /// + /// - `0` if the number is zero + /// - `1` if the number is positive + /// - `-1` if the number is negative + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + /// #![feature(wrapping_int_impl)] + /// use std::num::Wrapping; + /// + #[doc = concat!("assert_eq!(Wrapping(10", stringify!($t), ").signum(), Wrapping(1));")] + #[doc = concat!("assert_eq!(Wrapping(0", stringify!($t), ").signum(), Wrapping(0));")] + #[doc = concat!("assert_eq!(Wrapping(-10", stringify!($t), ").signum(), Wrapping(-1));")] + /// ``` + #[inline] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[unstable(feature = "wrapping_int_impl", issue = "32463")] + pub fn signum(self) -> Wrapping<$t> { + Wrapping(self.0.signum()) + } + + /// Returns `true` if `self` is positive and `false` if the number is zero or + /// negative. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + /// #![feature(wrapping_int_impl)] + /// use std::num::Wrapping; + /// + #[doc = concat!("assert!(Wrapping(10", stringify!($t), ").is_positive());")] + #[doc = concat!("assert!(!Wrapping(-10", stringify!($t), ").is_positive());")] + /// ``` + #[must_use] + #[inline] + #[unstable(feature = "wrapping_int_impl", issue = "32463")] + pub const fn is_positive(self) -> bool { + self.0.is_positive() + } + + /// Returns `true` if `self` is negative and `false` if the number is zero or + /// positive. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + /// #![feature(wrapping_int_impl)] + /// use std::num::Wrapping; + /// + #[doc = concat!("assert!(Wrapping(-10", stringify!($t), ").is_negative());")] + #[doc = concat!("assert!(!Wrapping(10", stringify!($t), ").is_negative());")] + /// ``` + #[must_use] + #[inline] + #[unstable(feature = "wrapping_int_impl", issue = "32463")] + pub const fn is_negative(self) -> bool { + self.0.is_negative() + } + } + )*) +} + +wrapping_int_impl_signed! { isize i8 i16 i32 i64 i128 } + +macro_rules! wrapping_int_impl_unsigned { + ($($t:ty)*) => ($( + impl Wrapping<$t> { + /// Returns the number of leading zeros in the binary representation of `self`. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + /// #![feature(wrapping_int_impl)] + /// use std::num::Wrapping; + /// + #[doc = concat!("let n = Wrapping(", stringify!($t), "::MAX) >> 2;")] + /// + /// assert_eq!(n.leading_zeros(), 2); + /// ``` + #[inline] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[unstable(feature = "wrapping_int_impl", issue = "32463")] + pub const fn leading_zeros(self) -> u32 { + self.0.leading_zeros() + } + + /// Returns `true` if and only if `self == 2^k` for some `k`. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + /// #![feature(wrapping_int_impl)] + /// use std::num::Wrapping; + /// + #[doc = concat!("assert!(Wrapping(16", stringify!($t), ").is_power_of_two());")] + #[doc = concat!("assert!(!Wrapping(10", stringify!($t), ").is_power_of_two());")] + /// ``` + #[must_use] + #[inline] + #[unstable(feature = "wrapping_int_impl", issue = "32463")] + pub fn is_power_of_two(self) -> bool { + self.0.is_power_of_two() + } + + /// Returns the smallest power of two greater than or equal to `self`. + /// + /// When return value overflows (i.e., `self > (1 << (N-1))` for type + /// `uN`), overflows to `2^N = 0`. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + /// #![feature(wrapping_next_power_of_two)] + /// use std::num::Wrapping; + /// + #[doc = concat!("assert_eq!(Wrapping(2", stringify!($t), ").next_power_of_two(), Wrapping(2));")] + #[doc = concat!("assert_eq!(Wrapping(3", stringify!($t), ").next_power_of_two(), Wrapping(4));")] + #[doc = concat!("assert_eq!(Wrapping(200_u8).next_power_of_two(), Wrapping(0));")] + /// ``` + #[inline] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[unstable(feature = "wrapping_next_power_of_two", issue = "32463", + reason = "needs decision on wrapping behaviour")] + pub fn next_power_of_two(self) -> Self { + Wrapping(self.0.wrapping_next_power_of_two()) + } + } + )*) +} + +wrapping_int_impl_unsigned! { usize u8 u16 u32 u64 u128 } + +mod shift_max { + #![allow(non_upper_case_globals)] + + #[cfg(target_pointer_width = "16")] + mod platform { + pub const usize: u32 = super::u16; + pub const isize: u32 = super::i16; + } + + #[cfg(target_pointer_width = "32")] + mod platform { + pub const usize: u32 = super::u32; + pub const isize: u32 = super::i32; + } + + #[cfg(target_pointer_width = "64")] + mod platform { + pub const usize: u32 = super::u64; + pub const isize: u32 = super::i64; + } + + pub const i8: u32 = (1 << 3) - 1; + pub const i16: u32 = (1 << 4) - 1; + pub const i32: u32 = (1 << 5) - 1; + pub const i64: u32 = (1 << 6) - 1; + pub const i128: u32 = (1 << 7) - 1; + pub use self::platform::isize; + + pub const u8: u32 = i8; + pub const u16: u32 = i16; + pub const u32: u32 = i32; + pub const u64: u32 = i64; + pub const u128: u32 = i128; + pub use self::platform::usize; +} |