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Diffstat (limited to 'vendor/num-traits/src/int.rs')
| -rw-r--r-- | vendor/num-traits/src/int.rs | 409 |
1 files changed, 409 insertions, 0 deletions
diff --git a/vendor/num-traits/src/int.rs b/vendor/num-traits/src/int.rs new file mode 100644 index 000000000..10e751a9d --- /dev/null +++ b/vendor/num-traits/src/int.rs @@ -0,0 +1,409 @@ +use core::ops::{BitAnd, BitOr, BitXor, Not, Shl, Shr}; + +use bounds::Bounded; +use ops::checked::*; +use ops::saturating::Saturating; +use {Num, NumCast}; + +/// Generic trait for primitive integers. +/// +/// The `PrimInt` trait is an abstraction over the builtin primitive integer types (e.g., `u8`, +/// `u32`, `isize`, `i128`, ...). It inherits the basic numeric traits and extends them with +/// bitwise operators and non-wrapping arithmetic. +/// +/// The trait explicitly inherits `Copy`, `Eq`, `Ord`, and `Sized`. The intention is that all +/// types implementing this trait behave like primitive types that are passed by value by default +/// and behave like builtin integers. Furthermore, the types are expected to expose the integer +/// value in binary representation and support bitwise operators. The standard bitwise operations +/// (e.g., bitwise-and, bitwise-or, right-shift, left-shift) are inherited and the trait extends +/// these with introspective queries (e.g., `PrimInt::count_ones()`, `PrimInt::leading_zeros()`), +/// bitwise combinators (e.g., `PrimInt::rotate_left()`), and endianness converters (e.g., +/// `PrimInt::to_be()`). +/// +/// All `PrimInt` types are expected to be fixed-width binary integers. The width can be queried +/// via `T::zero().count_zeros()`. The trait currently lacks a way to query the width at +/// compile-time. +/// +/// While a default implementation for all builtin primitive integers is provided, the trait is in +/// no way restricted to these. Other integer types that fulfil the requirements are free to +/// implement the trait was well. +/// +/// This trait and many of the method names originate in the unstable `core::num::Int` trait from +/// the rust standard library. The original trait was never stabilized and thus removed from the +/// standard library. +pub trait PrimInt: + Sized + + Copy + + Num + + NumCast + + Bounded + + PartialOrd + + Ord + + Eq + + Not<Output = Self> + + BitAnd<Output = Self> + + BitOr<Output = Self> + + BitXor<Output = Self> + + Shl<usize, Output = Self> + + Shr<usize, Output = Self> + + CheckedAdd<Output = Self> + + CheckedSub<Output = Self> + + CheckedMul<Output = Self> + + CheckedDiv<Output = Self> + + Saturating +{ + /// Returns the number of ones in the binary representation of `self`. + /// + /// # Examples + /// + /// ``` + /// use num_traits::PrimInt; + /// + /// let n = 0b01001100u8; + /// + /// assert_eq!(n.count_ones(), 3); + /// ``` + fn count_ones(self) -> u32; + + /// Returns the number of zeros in the binary representation of `self`. + /// + /// # Examples + /// + /// ``` + /// use num_traits::PrimInt; + /// + /// let n = 0b01001100u8; + /// + /// assert_eq!(n.count_zeros(), 5); + /// ``` + fn count_zeros(self) -> u32; + + /// Returns the number of leading zeros in the binary representation + /// of `self`. + /// + /// # Examples + /// + /// ``` + /// use num_traits::PrimInt; + /// + /// let n = 0b0101000u16; + /// + /// assert_eq!(n.leading_zeros(), 10); + /// ``` + fn leading_zeros(self) -> u32; + + /// Returns the number of trailing zeros in the binary representation + /// of `self`. + /// + /// # Examples + /// + /// ``` + /// use num_traits::PrimInt; + /// + /// let n = 0b0101000u16; + /// + /// assert_eq!(n.trailing_zeros(), 3); + /// ``` + fn trailing_zeros(self) -> u32; + + /// Shifts the bits to the left by a specified amount, `n`, wrapping + /// the truncated bits to the end of the resulting integer. + /// + /// # Examples + /// + /// ``` + /// use num_traits::PrimInt; + /// + /// let n = 0x0123456789ABCDEFu64; + /// let m = 0x3456789ABCDEF012u64; + /// + /// assert_eq!(n.rotate_left(12), m); + /// ``` + fn rotate_left(self, n: u32) -> Self; + + /// Shifts the bits to the right by a specified amount, `n`, wrapping + /// the truncated bits to the beginning of the resulting integer. + /// + /// # Examples + /// + /// ``` + /// use num_traits::PrimInt; + /// + /// let n = 0x0123456789ABCDEFu64; + /// let m = 0xDEF0123456789ABCu64; + /// + /// assert_eq!(n.rotate_right(12), m); + /// ``` + fn rotate_right(self, n: u32) -> Self; + + /// Shifts the bits to the left by a specified amount, `n`, filling + /// zeros in the least significant bits. + /// + /// This is bitwise equivalent to signed `Shl`. + /// + /// # Examples + /// + /// ``` + /// use num_traits::PrimInt; + /// + /// let n = 0x0123456789ABCDEFu64; + /// let m = 0x3456789ABCDEF000u64; + /// + /// assert_eq!(n.signed_shl(12), m); + /// ``` + fn signed_shl(self, n: u32) -> Self; + + /// Shifts the bits to the right by a specified amount, `n`, copying + /// the "sign bit" in the most significant bits even for unsigned types. + /// + /// This is bitwise equivalent to signed `Shr`. + /// + /// # Examples + /// + /// ``` + /// use num_traits::PrimInt; + /// + /// let n = 0xFEDCBA9876543210u64; + /// let m = 0xFFFFEDCBA9876543u64; + /// + /// assert_eq!(n.signed_shr(12), m); + /// ``` + fn signed_shr(self, n: u32) -> Self; + + /// Shifts the bits to the left by a specified amount, `n`, filling + /// zeros in the least significant bits. + /// + /// This is bitwise equivalent to unsigned `Shl`. + /// + /// # Examples + /// + /// ``` + /// use num_traits::PrimInt; + /// + /// let n = 0x0123456789ABCDEFi64; + /// let m = 0x3456789ABCDEF000i64; + /// + /// assert_eq!(n.unsigned_shl(12), m); + /// ``` + fn unsigned_shl(self, n: u32) -> Self; + + /// Shifts the bits to the right by a specified amount, `n`, filling + /// zeros in the most significant bits. + /// + /// This is bitwise equivalent to unsigned `Shr`. + /// + /// # Examples + /// + /// ``` + /// use num_traits::PrimInt; + /// + /// let n = -8i8; // 0b11111000 + /// let m = 62i8; // 0b00111110 + /// + /// assert_eq!(n.unsigned_shr(2), m); + /// ``` + fn unsigned_shr(self, n: u32) -> Self; + + /// Reverses the byte order of the integer. + /// + /// # Examples + /// + /// ``` + /// use num_traits::PrimInt; + /// + /// let n = 0x0123456789ABCDEFu64; + /// let m = 0xEFCDAB8967452301u64; + /// + /// assert_eq!(n.swap_bytes(), m); + /// ``` + fn swap_bytes(self) -> Self; + + /// Convert 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 + /// + /// ``` + /// use num_traits::PrimInt; + /// + /// let n = 0x0123456789ABCDEFu64; + /// + /// if cfg!(target_endian = "big") { + /// assert_eq!(u64::from_be(n), n) + /// } else { + /// assert_eq!(u64::from_be(n), n.swap_bytes()) + /// } + /// ``` + fn from_be(x: Self) -> Self; + + /// Convert 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 + /// + /// ``` + /// use num_traits::PrimInt; + /// + /// let n = 0x0123456789ABCDEFu64; + /// + /// if cfg!(target_endian = "little") { + /// assert_eq!(u64::from_le(n), n) + /// } else { + /// assert_eq!(u64::from_le(n), n.swap_bytes()) + /// } + /// ``` + fn from_le(x: Self) -> Self; + + /// Convert `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 + /// + /// ``` + /// use num_traits::PrimInt; + /// + /// let n = 0x0123456789ABCDEFu64; + /// + /// if cfg!(target_endian = "big") { + /// assert_eq!(n.to_be(), n) + /// } else { + /// assert_eq!(n.to_be(), n.swap_bytes()) + /// } + /// ``` + fn to_be(self) -> Self; + + /// Convert `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 + /// + /// ``` + /// use num_traits::PrimInt; + /// + /// let n = 0x0123456789ABCDEFu64; + /// + /// if cfg!(target_endian = "little") { + /// assert_eq!(n.to_le(), n) + /// } else { + /// assert_eq!(n.to_le(), n.swap_bytes()) + /// } + /// ``` + fn to_le(self) -> Self; + + /// Raises self to the power of `exp`, using exponentiation by squaring. + /// + /// # Examples + /// + /// ``` + /// use num_traits::PrimInt; + /// + /// assert_eq!(2i32.pow(4), 16); + /// ``` + fn pow(self, exp: u32) -> Self; +} + +macro_rules! prim_int_impl { + ($T:ty, $S:ty, $U:ty) => { + impl PrimInt for $T { + #[inline] + fn count_ones(self) -> u32 { + <$T>::count_ones(self) + } + + #[inline] + fn count_zeros(self) -> u32 { + <$T>::count_zeros(self) + } + + #[inline] + fn leading_zeros(self) -> u32 { + <$T>::leading_zeros(self) + } + + #[inline] + fn trailing_zeros(self) -> u32 { + <$T>::trailing_zeros(self) + } + + #[inline] + fn rotate_left(self, n: u32) -> Self { + <$T>::rotate_left(self, n) + } + + #[inline] + fn rotate_right(self, n: u32) -> Self { + <$T>::rotate_right(self, n) + } + + #[inline] + fn signed_shl(self, n: u32) -> Self { + ((self as $S) << n) as $T + } + + #[inline] + fn signed_shr(self, n: u32) -> Self { + ((self as $S) >> n) as $T + } + + #[inline] + fn unsigned_shl(self, n: u32) -> Self { + ((self as $U) << n) as $T + } + + #[inline] + fn unsigned_shr(self, n: u32) -> Self { + ((self as $U) >> n) as $T + } + + #[inline] + fn swap_bytes(self) -> Self { + <$T>::swap_bytes(self) + } + + #[inline] + fn from_be(x: Self) -> Self { + <$T>::from_be(x) + } + + #[inline] + fn from_le(x: Self) -> Self { + <$T>::from_le(x) + } + + #[inline] + fn to_be(self) -> Self { + <$T>::to_be(self) + } + + #[inline] + fn to_le(self) -> Self { + <$T>::to_le(self) + } + + #[inline] + fn pow(self, exp: u32) -> Self { + <$T>::pow(self, exp) + } + } + }; +} + +// prim_int_impl!(type, signed, unsigned); +prim_int_impl!(u8, i8, u8); +prim_int_impl!(u16, i16, u16); +prim_int_impl!(u32, i32, u32); +prim_int_impl!(u64, i64, u64); +#[cfg(has_i128)] +prim_int_impl!(u128, i128, u128); +prim_int_impl!(usize, isize, usize); +prim_int_impl!(i8, i8, u8); +prim_int_impl!(i16, i16, u16); +prim_int_impl!(i32, i32, u32); +prim_int_impl!(i64, i64, u64); +#[cfg(has_i128)] +prim_int_impl!(i128, i128, u128); +prim_int_impl!(isize, isize, usize); |