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| author | Phlosioneer <mattmdrr2@gmail.com> | 2018-03-06 23:17:49 -0500 |
|---|---|---|
| committer | Phlosioneer <mattmdrr2@gmail.com> | 2018-03-19 01:39:37 -0400 |
| commit | 612c4a95bce4c4dc0cddc5ab374fcb262039aede (patch) | |
| tree | 52b7ce643c0072ef287d3540abf74651f703c809 /src/libcore/num | |
| parent | 5508b27145cfb82896ae838e6aca0cd48750796f (diff) | |
| download | rust-612c4a95bce4c4dc0cddc5ab374fcb262039aede.tar.gz rust-612c4a95bce4c4dc0cddc5ab374fcb262039aede.zip | |
Impl Integer methods for Wrapping
Wrapping<T> now implements: count_ones, count_zeros, leading_zeros, trailing_zeros, rotate_left, rotate_right, swap_bytes, from_be, from_le, to_be, to_le, and pow where T is: u8, u16, u32, u64, usize, i8, i16, i32, i64, or isize. Docs were written for all these methods, as well as examples. The examples mirror the ones on u8, u16, etc... for consistency. Closes #32463
Diffstat (limited to 'src/libcore/num')
| -rw-r--r-- | src/libcore/num/wrapping.rs | 299 |
1 files changed, 299 insertions, 0 deletions
diff --git a/src/libcore/num/wrapping.rs b/src/libcore/num/wrapping.rs index ae1b0b3ce11..6c110aa0523 100644 --- a/src/libcore/num/wrapping.rs +++ b/src/libcore/num/wrapping.rs @@ -317,11 +317,307 @@ macro_rules! wrapping_impl { } forward_ref_unop! { impl 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 number of ones in the binary representation of + /// `self`. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + /// #![feature(wrapping_int_impl)] + /// use std::num::Wrapping; + /// + /// let n: Wrapping<i8> = Wrapping(-0b1000_0000); + /// + /// assert_eq!(n.count_ones(), 1); + /// ``` + #[inline] + #[unstable(feature = "wrapping_int_impl", issue = "32463")] + pub 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; + /// + /// let n: Wrapping<i8> = Wrapping(-0b1000_0000); + /// + /// assert_eq!(n.count_zeros(), 7); + /// ``` + #[inline] + #[unstable(feature = "wrapping_int_impl", issue = "32463")] + pub fn count_zeros(self) -> u32 { + self.0.count_zeros() + } + + /// Returns the number of leading zeros in the binary representation + /// of `self`. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + /// #![feature(wrapping_int_impl)] + /// use std::num::Wrapping; + /// + /// let n: Wrapping<i16> = Wrapping(-1); + /// + /// assert_eq!(n.leading_zeros(), 0); + /// ``` + #[inline] + #[unstable(feature = "wrapping_int_impl", issue = "32463")] + pub fn leading_zeros(self) -> u32 { + self.0.leading_zeros() + } + + /// Returns the number of trailing zeros in the binary representation + /// of `self`. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + /// #![feature(wrapping_int_impl)] + /// use std::num::Wrapping; + /// + /// let n: Wrapping<i8> = Wrapping(-4); + /// + /// assert_eq!(n.trailing_zeros(), 2); + /// ``` + #[inline] + #[unstable(feature = "wrapping_int_impl", issue = "32463")] + pub 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 `>>`! + /// + /// # 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] + #[unstable(feature = "wrapping_int_impl", issue = "32463")] + pub 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 `<<`! + /// + /// # 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] + #[unstable(feature = "wrapping_int_impl", issue = "32463")] + pub 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] + #[unstable(feature = "wrapping_int_impl", issue = "32463")] + pub fn swap_bytes(self) -> Self { + Wrapping(self.0.swap_bytes()) + } + + /// 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; + /// + /// let n: Wrapping<i64> = Wrapping(0x0123456789ABCDEF); + /// + /// if cfg!(target_endian = "big") { + /// assert_eq!(Wrapping::<i64>::from_be(n), n); + /// } else { + /// assert_eq!(Wrapping::<i64>::from_be(n), n.swap_bytes()); + /// } + /// ``` + #[inline] + #[unstable(feature = "wrapping_int_impl", issue = "32463")] + pub 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; + /// + /// let n: Wrapping<i64> = Wrapping(0x0123456789ABCDEF); + /// + /// if cfg!(target_endian = "little") { + /// assert_eq!(Wrapping::<i64>::from_le(n), n); + /// } else { + /// assert_eq!(Wrapping::<i64>::from_le(n), n.swap_bytes()); + /// } + /// ``` + #[inline] + #[unstable(feature = "wrapping_int_impl", issue = "32463")] + pub 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; + /// + /// let n: Wrapping<i64> = Wrapping(0x0123456789ABCDEF); + /// + /// if cfg!(target_endian = "big") { + /// assert_eq!(n.to_be(), n); + /// } else { + /// assert_eq!(n.to_be(), n.swap_bytes()); + /// } + /// ``` + #[inline] + #[unstable(feature = "wrapping_int_impl", issue = "32463")] + pub 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; + /// + /// let n: Wrapping<i64> = Wrapping(0x0123456789ABCDEF); + /// + /// if cfg!(target_endian = "little") { + /// assert_eq!(n.to_le(), n); + /// } else { + /// assert_eq!(n.to_le(), n.swap_bytes()); + /// } + /// ``` + #[inline] + #[unstable(feature = "wrapping_int_impl", issue = "32463")] + pub 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; + /// + /// let x: Wrapping<i32> = Wrapping(2); // or any other integer type + /// + /// assert_eq!(x.pow(4), Wrapping(16)); + #[inline] + #[unstable(feature = "wrapping_int_impl", issue = "32463")] + pub fn pow(self, exp: u32) -> Self { + Wrapping(self.0.pow(exp)) + } + } + )*) +} + +wrapping_int_impl! { usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 } + + mod shift_max { #![allow(non_upper_case_globals)] @@ -355,3 +651,6 @@ mod shift_max { pub const u64: u32 = i64; pub use self::platform::usize; } + + + |
