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// // Copyright 2016 The u12 Developers. See the COPYRIGHT // file at the top-level directory of this distribution. // // Licensed under the MIT license <LICENSE-MIT or http://opensource.org/licenses/MIT>. // All files in the project carrying such notice may not be copied, modified, or // distributed except according to those terms. // use std::cmp; use std::marker; use std::ops::{Add, BitAnd, BitOr, BitXor, Div, Mul, Not, Rem, Shl, Shr, Sub}; #[derive(Debug,Clone,Copy,PartialEq,Eq,PartialOrd,Ord)] pub struct U12(u16); // MARK: - Literal Macro /// Creates a 12-bit value via unchecked-into conversion. /// This is meant to simplify describing U12 literal values, as the /// `$x` parameter is first bound to a 16-bit value. This allows the compiler to /// elide the type of the literal, and does compile-time validation that no /// literal greater than `0xFFFF` is specified; this will panic for values /// in the range `0x1000...0xFFFF`. /// /// # Examples /// Basic usage: /// /// ```rust /// # #[macro_use] extern crate twelve_bit; /// use twelve_bit::u12::*; /// # fn main() { /// assert_eq!(u12![0], U12::min_value()); /// assert_eq!(u12![4095], U12::max_value()); /// # } /// ``` #[macro_export] macro_rules! u12 { ( $x:expr ) => {{ let x: u16 = $x; let value: U12 = x.unchecked_into(); value }} } // MARK: - Public Constants /// The largest value representable by the `U12` type. pub const MAX: U12 = U12(0xFFF); /// The smallest value representable by the `U12` type. pub const MIN: U12 = U12(0x000); // MARK: - Implementation impl U12 { /// Returns the smallest value that can be represented by this integer type. pub fn min_value() -> Self { MIN } /// Returns the largest value that can be represented by this integer type. pub fn max_value() -> Self { MAX } /// Returns the number of ones in the binary representation of `self`. /// # Examples /// Basic usage: /// /// ```rust /// # #[macro_use] extern crate twelve_bit; /// use twelve_bit::u12::*; /// # fn main() { /// assert_eq!(u12![0b000000000000].count_ones(), 0); /// assert_eq!(u12![0b001011111100].count_ones(), 7); /// assert_eq!(u12![0b111111111111].count_ones(), 12) /// # } /// ``` pub fn count_ones(self) -> u32 { self.0.count_ones() } /// Returns the number of zeros in the binary representation of `self`. /// # Examples /// Basic usage: /// /// ```rust /// # #[macro_use] extern crate twelve_bit; /// use twelve_bit::u12::*; /// # fn main() { /// assert_eq!(u12![0b000000000000].count_zeros(), 12); /// assert_eq!(u12![0b001011111000].count_zeros(), 6); /// assert_eq!(u12![0b111111111111].count_zeros(), 0) /// # } /// ``` pub fn count_zeros(self) -> u32 { self.0.count_zeros() - 4 } /// Returns the number of leading zeros in the binary representation of `self`. /// # Examples /// Basic usage: /// /// ```rust /// # #[macro_use] extern crate twelve_bit; /// use twelve_bit::u12::*; /// # fn main() { /// assert_eq!(u12![0b111111111111].leading_zeros(), 0); /// assert_eq!(u12![0b001011111000].leading_zeros(), 2); /// assert_eq!(u12![0b000011111000].leading_zeros(), 4); /// assert_eq!(u12![0b000000000000].leading_zeros(), 12); /// # } /// ``` pub fn leading_zeros(self) -> u32 { self.0.leading_zeros() - 4 } /// Returns the number of trailing zeros in the binary representation of `self`. /// # Examples /// Basic usage: /// /// ```rust /// # #[macro_use] extern crate twelve_bit; /// use twelve_bit::u12::*; /// # fn main() { /// assert_eq!(u12![0b111111111111].trailing_zeros(), 0); /// assert_eq!(u12![0b001011111000].trailing_zeros(), 3); /// assert_eq!(u12![0b001011110000].trailing_zeros(), 4); /// assert_eq!(u12![0b000000000000].trailing_zeros(), 12); /// # } /// ``` pub fn trailing_zeros(self) -> u32 { cmp::min(self.0.trailing_zeros(), 12) } /// Checked integer addition. /// Computes `self + other`, returning `None` if overflow occurred. /// /// # Examples /// Basic usage: /// /// ```rust /// # #[macro_use] extern crate twelve_bit; /// use twelve_bit::u12::*; /// # fn main() { /// assert_eq!(u12![1].checked_add(u12![1]), Some(u12![2])); /// assert_eq!(U12::max_value().checked_add(u12![1]), None); /// # } /// ``` pub fn checked_add(self, other: Self) -> Option<Self> { match self.0 + other.0 { result @ 0...4095 => Some(U12(result)), _ => None } } /// Saturating integer addition. /// Computes `self + other`, saturating at the numeric bounds instead of overflowing. /// /// # Examples /// Basic usage: /// /// ``` /// use twelve_bit::u12::U12; /// /// assert_eq!(U12::from(1u8).saturating_add(1u8.into()), U12::from(2u8)); /// assert_eq!(U12::max_value().saturating_add(1u8.into()), U12::max_value()); /// ``` pub fn saturating_add(self, other: Self) -> Self { match self.0 + other.0 { result @ 0...4095 => U12(result), _ => Self::max_value() } } /// Wrapping (modular) addition. /// Computes `self + other`, wrapping around at the boundary of the type. /// /// # Examples /// Basic usage: /// /// ``` /// use twelve_bit::u12::U12; /// /// assert_eq!(U12::from(1u8).wrapping_add(1u8.into()), U12::from(2u8)); /// assert_eq!(U12::max_value().wrapping_add(3u8.into()), U12::from(2u8)); /// ``` pub fn wrapping_add(self, other: Self) -> Self { U12((self.0 + other.0) & 0xFFF) } /// Overflowing addition. /// Computes `self + other`, returning a tuple of the addition along with a /// boolean indicating whether an arithmetic overflow would occur. /// If an overflow would have occurred then the wrapped value is returned. /// /// # Examples /// Basic usage: /// /// ``` /// use twelve_bit::u12::U12; /// /// assert_eq!(U12::from(1u8).overflowing_add(1u8.into()), (U12::from(2u8), false)); /// assert_eq!(U12::max_value().overflowing_add(3u8.into()), (U12::from(2u8), true)); /// ``` pub fn overflowing_add(self, other: Self) -> (Self, bool) { match self.checked_add(other) { Some(result) => (result, false), None => (self.wrapping_add(other), true) } } /// Checked integer subtraction. /// Computes `self - other`, returning `None` if underflow occurred. /// /// # Examples /// Basic usage: /// /// ``` /// use twelve_bit::u12::U12; /// /// assert_eq!(U12::from(1u8).checked_sub(1u8.into()), Some(U12::from(0u8))); /// assert_eq!(U12::min_value().checked_sub(1u8.into()), None); /// ``` pub fn checked_sub(self, other: Self) -> Option<Self> { self.0 .checked_sub(other.0) .map(|value| U12(value)) } /// Saturating integer subtraction. /// Computes `self - other`, saturating at the numeric bounds instead of overflowing. /// /// # Examples /// Basic usage: /// /// ``` /// use twelve_bit::u12::U12; /// /// assert_eq!(U12::from(1u8).saturating_sub(1u8.into()), U12::min_value()); /// assert_eq!(U12::min_value().saturating_sub(5u8.into()), U12::min_value()); /// ``` pub fn saturating_sub(self, other: Self) -> Self { U12(self.0.saturating_sub(other.0)) } /// Wrapping (modular) subtraction. /// Computes `self - other`, wrapping around at the boundary of the type. /// /// # Examples /// Basic usage: /// /// ``` /// use twelve_bit::u12::*; /// /// assert_eq!(U12::from(1u8).wrapping_sub(1u8.into()), U12::min_value()); /// assert_eq!(U12::min_value().wrapping_sub(5u8.into()), (0xFFB as u16).unchecked_into()); /// ``` pub fn wrapping_sub(self, other: Self) -> Self { U12(self.0.wrapping_sub(other.0) & 0xFFF) } /// Overflowing subtraction. /// Computes `self - other`, returning a tuple of the subtraction result along with a /// boolean indicating whether an arithmetic underflow would occur. /// If an underflow would have occurred then the wrapped value is returned. /// /// # Examples /// Basic usage: /// /// ``` /// use twelve_bit::u12::*; /// /// assert_eq!(U12::from(1u8).overflowing_sub(1u8.into()), (U12::from(0u8), false)); /// assert_eq!(U12::min_value().overflowing_sub(1u8.into()), (0xFFFu16.unchecked_into(), true)); /// ``` pub fn overflowing_sub(self, other: Self) -> (Self, bool) { match self.checked_sub(other) { Some(result) => (result, false), None => (self.wrapping_sub(other), true) } } /// Checked integer multiplication. /// Computes `self * other`, returning `None` if overflow occurred. /// /// # Examples /// Basic usage: /// /// ``` /// use twelve_bit::u12::*; /// /// assert_eq!(U12::from(2u8).checked_mul(255u8.into()), Some((510 as u16).unchecked_into())); /// assert_eq!(U12::from(2u8).checked_mul((2048u16).unchecked_into()), None); /// assert_eq!(U12::from(2u8).checked_mul((4095u16).unchecked_into()), None); /// ``` pub fn checked_mul(self, other: Self) -> Option<Self> { match self.0.checked_mul(other.0) { Some(small) if small < 4096 => Some(U12(small)), _ => None } } /// Saturating integer multiplication. /// Computes `self * other`, saturating at the numeric bounds instead of overflowing. /// /// # Examples /// Basic usage: /// /// ``` /// use twelve_bit::u12::*; /// /// assert_eq!(U12::from(2u8).saturating_mul(1u8.into()), 2u8.into()); /// assert_eq!(U12::from(2u8).saturating_mul((2048u16).unchecked_into()), U12::max_value()); /// assert_eq!(U12::from(2u8).saturating_mul((4095u16).unchecked_into()), U12::max_value()); /// ``` pub fn saturating_mul(self, other: Self) -> Self { match self.0.checked_mul(other.0) { Some(small) if small < 4096 => U12(small), _ => Self::max_value() } } /// Wrapping (modular) multiplication. /// Computes `self * other`, wrapping around at the boundary of the type. /// /// # Examples /// Basic usage: /// /// ``` /// use twelve_bit::u12::*; /// /// assert_eq!(U12::from(2u8).wrapping_mul(1u8.into()), 2u8.into()); /// assert_eq!(U12::from(2u8).wrapping_mul((2048u16).unchecked_into()), 0u8.into()); /// assert_eq!(U12::from(2u8).wrapping_mul((4095u16).unchecked_into()), (0xFFE as u16).unchecked_into()); /// ``` pub fn wrapping_mul(self, other: Self) -> Self { U12(self.0.wrapping_mul(other.0) & 0xFFF) } /// Overflowing multiplication. /// Returns a tuple of the multiplication along with a boolean indicating whether an arithmetic /// overflow would occur. If an overflow would have occurred then the wrapped value is returned. /// /// # Examples /// Basic usage: /// /// ```rust /// # #[macro_use] extern crate twelve_bit; /// use twelve_bit::u12::*; /// # fn main() { /// assert_eq!(u12![2].overflowing_mul(u12![1]), (u12![2], false)); /// assert_eq!(u12![2].overflowing_mul(u12![2048]), (u12![0], true)); /// assert_eq!(u12![2].overflowing_mul(u12![4095]), (u12![0xFFE], true)); /// # } /// ``` pub fn overflowing_mul(self, other: Self) -> (Self, bool) { match self.checked_mul(other) { Some(result) => (result, false), None => (self.wrapping_mul(other), true) } } /// Checked integer division. /// Computes `self / other`, returning None if other == 0 or the operation results in /// underflow or overflow. /// /// # Examples /// Basic usage: /// /// ``` /// use twelve_bit::u12::*; /// /// assert_eq!(U12::from(2u8).checked_div(0u8.into()), None); /// assert_eq!(U12::from(2u8).checked_div((2048u16).unchecked_into()), Some(U12::min_value())); /// assert_eq!(U12::from(2u8).checked_div(2u8.into()), Some(U12::from(1u8))); /// ``` pub fn checked_div(self, other: Self) -> Option<Self> { self.0 .checked_div(other.0) .map(|small| U12(small)) } /// Wrapping (modular) division. /// Computes self / other. Wrapped division on unsigned types is just normal division. /// There's no way wrapping could ever happen. This function exists, so that all operations /// are accounted for in the wrapping operations. /// /// # Examples /// Basic usage: /// /// ``` /// use twelve_bit::u12::*; /// /// assert_eq!(U12::from(2u8).wrapping_div((2048u16).unchecked_into()), U12::min_value()); /// assert_eq!(U12::from(2u8).wrapping_div(2u8.into()), U12::from(1u8)); /// ``` pub fn wrapping_div(self, other: Self) -> Self { U12(self.0.wrapping_div(other.0)) } /// Calculates the divisor when the receiver is divided by `rhs`. /// Returns a tuple of the divisor along with a boolean indicating whether an arithmetic /// overflow would occur. Note that for unsigned integers overflow never occurs, /// so the second value is always false. /// /// # Examples /// Basic usage: /// /// ```rust /// # #[macro_use] extern crate twelve_bit; /// use twelve_bit::u12::*; /// # fn main() { /// assert_eq!(u12![2].overflowing_div(u12![1]), (u12![2], false)); /// assert_eq!(u12![2048].overflowing_div(u12![2]), (u12![1024], false)); /// assert_eq!(u12![4095].overflowing_div(u12![2]), (u12![2047], false)); /// # } /// ``` pub fn overflowing_div(self, other: Self) -> (Self, bool) { (self.wrapping_div(other), false) } /// Checked integer negation. /// Computes `-self`, returning `None` unless `self == 0`. /// Note that negating any positive integer will overflow. /// /// # Examples /// Basic usage: /// /// ``` /// use twelve_bit::u12::*; /// /// assert_eq!(U12::from(0u8).checked_neg(), Some(0u8.into())); /// assert_eq!(U12::from(2u8).checked_neg(), None); /// ``` pub fn checked_neg(self) -> Option<Self> { match self.0 { 0 => Some(self), _ => None } } /// Wrapping (modular) negation. /// Computes `-self`, wrapping around at the boundary of the type. /// /// # Examples /// Basic usage: /// /// ``` /// use twelve_bit::u12::*; /// /// assert_eq!(U12::from(2u8).wrapping_neg(), 0xFFEu16.unchecked_into()); /// assert_eq!(U12::from(255u8).wrapping_neg(), 0xF01u16.unchecked_into()); /// ``` pub fn wrapping_neg(self) -> Self { U12(self.0.wrapping_neg() & 0xFFF) } /// Negates self in an overflowing fashion. /// Returns `!self + 1` using wrapping operations to return the value that /// represents the negation of this unsigned value. Note that for positive /// unsigned values overflow always occurs, but negating `0` does not overflow. /// /// # Examples /// Basic usage: /// /// ``` /// use twelve_bit::u12::*; /// /// assert_eq!(U12::from(0u8).overflowing_neg(), (0u8.into(), false)); /// assert_eq!(U12::from(2u8).overflowing_neg(), (0xFFEu16.unchecked_into(), true)); /// ``` pub fn overflowing_neg(self) -> (U12, bool) { match self.0 { 0 => (self, false), _ => (self.wrapping_neg(), true) } } /// Checked integer remainder. /// Computes `self % other`, returning `None` if `other == 0` or the /// operation results in underflow or overflow. /// /// # Examples /// Basic usage: /// /// ```rust /// # #[macro_use] extern crate twelve_bit; /// use twelve_bit::u12::*; /// # fn main() { /// assert_eq!(u12![5].checked_rem(u12![2]), Some(u12![1])); /// assert_eq!(u12![5].checked_rem(u12![0]), None); /// # } /// ``` pub fn checked_rem(self, other: Self) -> Option<Self> { self.0 .checked_rem(other.0) .map(|value| U12(value)) } /// Wrapping (modular) integer remainder. /// Computes `self % other`. Wrapped remainder calculation on unsigned types /// is just the regular remainder calculation. There's no way wrapping could ever /// happen. This function exists, so that all operations are accounted for in the /// wrapping operations. /// /// # Examples /// Basic usage: /// /// ```rust /// # #[macro_use] extern crate twelve_bit; /// use twelve_bit::u12::*; /// # fn main() { /// assert_eq!(u12![100].wrapping_rem(u12![10]), u12![0]); /// # } /// ``` pub fn wrapping_rem(self, other: Self) -> Self { U12(self.0.wrapping_rem(other.0)) } /// Calculates the remainder when `self` is divided by `other`. /// Returns a tuple of the remainder after dividing along with a boolean indicating /// whether an arithmetic overflow would occur. Note that for unsigned integers /// overflow never occurs, so the second value is always false. /// /// # Panics /// This function will panic if `other` is `0`. /// /// # Examples /// Basic usage: /// /// ```rust /// # #[macro_use] extern crate twelve_bit; /// use twelve_bit::u12::*; /// # fn main() { /// assert_eq!(u12![5].overflowing_rem(u12![2]), (u12![1], false)); /// # } /// ``` pub fn overflowing_rem(self, other: Self) -> (Self, bool) { let (result, overflow) = self.0.overflowing_rem(other.0); (U12(result), overflow) } /// Checked shift left. /// Computes `self << rhs`, returning `None` if `rhs` is larger than or equal to /// the number of bits in the receiver. /// /// # Examples /// Basic usage: /// /// ```rust /// # #[macro_use] extern crate twelve_bit; /// use twelve_bit::u12::*; /// # fn main() { /// assert_eq!(u12![0b000000000001].checked_shl(12), None); /// assert_eq!(u12![0b000000000001].checked_shl(1), Some(u12![0b000000000010])); /// assert_eq!(u12![0b000000000001].checked_shl(11), Some(u12![0b100000000000])); /// # } /// ``` pub fn checked_shl(self, rhs: u32) -> Option<Self> { if rhs >= 12 { None } else { self.0 .checked_shl(rhs) .map(|value| U12(value)) } } /// Panic-free bitwise shift-left; yields `self << mask(rhs)`, where mask removes any /// high-order bits of rhs that would cause the shift to exceed the bitwidth of the type. /// /// # Examples /// Basic usage: /// /// ```rust /// # #[macro_use] extern crate twelve_bit; /// use twelve_bit::u12::*; /// # fn main() { /// assert_eq!(u12![0b000000000001].wrapping_shl(12), u12![0b000000000001]); /// assert_eq!(u12![0b000000000001].wrapping_shl( 1), u12![0b000000000010]); /// assert_eq!(u12![0b000000000001].wrapping_shl(11), u12![0b100000000000]); /// # } /// ``` pub fn wrapping_shl(self, rhs: u32) -> Self { self.checked_shl(rhs % 12).unwrap() } /// Shifts self left by rhs bits. /// Returns a tuple of the shifted version of the receiver along with a boolean /// indicating whether the shift value was larger than or equal to the number of /// bits. If the shift value is too large, then value is masked `(N-1)` where N /// is the number of bits, and this value is then used to perform the shift. /// /// # Examples /// Basic usage: /// /// ```rust /// # #[macro_use] extern crate twelve_bit; /// use twelve_bit::u12::*; /// # fn main() { /// assert_eq!(u12![0b000000000001].overflowing_shl(12), (u12![0b000000000001], true)); /// assert_eq!(u12![0b000000000001].overflowing_shl( 1), (u12![0b000000000010], false)); /// assert_eq!(u12![0b000000000001].overflowing_shl(11), (u12![0b100000000000], false)); /// # } /// ``` pub fn overflowing_shl(self, rhs: u32) -> (Self, bool) { (self.wrapping_shl(rhs), rhs >= 12) } /// Checked shift right. /// Computes `self >> rhs`, returning `None` if `rhs` is larger than or /// equal to the number of bits in the receiver. /// /// # Examples /// Basic usage: /// /// ```rust /// # #[macro_use] extern crate twelve_bit; /// use twelve_bit::u12::*; /// # fn main() { /// assert_eq!(u12![0b100000000000].checked_shr(12), None); /// assert_eq!(u12![0b100000000000].checked_shr( 1), Some(u12![0b010000000000])); /// assert_eq!(u12![0b100000000000].checked_shr(11), Some(u12![0b000000000001])); /// # } /// ``` pub fn checked_shr(self, rhs: u32) -> Option<Self> { if rhs >= 12 { None } else { self.0 .checked_shr(rhs) .map(|value| U12(value)) } } /// Panic-free bitwise shift-right; yields `self >> mask(rhs)`, where mask removes any /// high-order bits of rhs that would cause the shift to exceed the bitwidth of the type. /// /// # Examples /// Basic usage: /// /// ```rust /// # #[macro_use] extern crate twelve_bit; /// use twelve_bit::u12::*; /// # fn main() { /// assert_eq!(u12![0b100000000000].wrapping_shr(12), u12![0b100000000000]); /// assert_eq!(u12![0b100000000000].wrapping_shr( 1), u12![0b010000000000]); /// assert_eq!(u12![0b100000000000].wrapping_shr(11), u12![0b000000000001]); /// # } /// ``` pub fn wrapping_shr(self, rhs: u32) -> Self { self.checked_shr(rhs % 12).unwrap() } /// Shifts the receiver right by `rhs` bits. /// Returns a tuple of the shifted version of self along with a boolean indicating /// whether the shift value was larger than or equal to the number of bits. /// If the shift value is too large, then value is masked `(N-1)` where `N` is the /// number of bits, and this value is then used to perform the shift. /// /// # Examples /// Basic usage: /// /// ```rust /// # #[macro_use] extern crate twelve_bit; /// use twelve_bit::u12::*; /// # fn main() { /// assert_eq!(u12![0b100000000000].overflowing_shr(12), (u12![0b100000000000], true)); /// assert_eq!(u12![0b100000000000].overflowing_shr( 1), (u12![0b010000000000], false)); /// assert_eq!(u12![0b100000000000].overflowing_shr(11), (u12![0b000000000001], false)); /// # } /// ``` pub fn overflowing_shr(self, rhs: u32) -> (Self, bool) { (self.wrapping_shr(rhs), rhs >= 12) } /// Checked bitwise-and of the receiver with `rhs`. /// Computes `self & rhs`. This method cannot fail. /// /// # Examples /// Basic usage: /// /// ```rust /// # #[macro_use] extern crate twelve_bit; /// use twelve_bit::u12::*; /// # fn main() { /// assert_eq!(u12![0b111100001111].checked_bitand(u12![0b111100000000]), Some(u12![0b111100000000])); /// # } /// ``` pub fn checked_bitand(self, rhs: Self) -> Option<Self> { Some(U12(self.0.bitand(rhs.0))) } /// Checked bitwise-or of the receiver with `rhs`. /// Computes `self | rhs`. This method cannot fail. /// /// # Examples /// Basic usage: /// /// ```rust /// # #[macro_use] extern crate twelve_bit; /// use twelve_bit::u12::*; /// # fn main() { /// assert_eq!(u12![0b111100001111].checked_bitor(u12![0b111100000000]), Some(u12![0b111100001111])); /// # } /// ``` pub fn checked_bitor(self, rhs: Self) -> Option<Self> { Some(U12(self.0.bitor(rhs.0))) } /// Checked bitwise-xor of the receiver with `rhs`. /// Computes `self ^ rhs`. This method cannot fail. /// /// # Examples /// Basic usage: /// /// ```rust /// # #[macro_use] extern crate twelve_bit; /// use twelve_bit::u12::*; /// # fn main() { /// assert_eq!(u12![0b111100001111].checked_bitxor(u12![0b111100000000]), Some(u12![0b000000001111])); /// # } /// ``` pub fn checked_bitxor(self, rhs: Self) -> Option<Self> { Some(U12(self.0.bitxor(rhs.0))) } } // MARK: - Non-Failable Conversions - From Smaller Types impl From<u8> for U12 { fn from(small: u8) -> Self { U12(small as u16) } } // MARK: - Non-Failable Conversions - Into Larger Types /// Implements From<U12> for the specified type. macro_rules! impl_from_u12 { ($result:path) => { impl From<U12> for $result { fn from(small: U12) -> Self { small.0 as Self } } } } impl_from_u12!(u16); impl_from_u12!(u32); impl_from_u12!(u64); impl_from_u12!(usize); // MARK: - Failable Conversions - From Larger Types /// Trait for implementing failable conversions in a generic way. pub trait FailableInto<T> where Self: marker::Sized, T: marker::Sized { /// Returns the receiver as `Some(T)` if non-truncating, or `None`. fn failable_into(self) -> Option<T>; /// Returns the receiver as `T` by using `failable_into()` and unwrapping the result. /// /// # Panics /// This method will panic if `failable_into` fails. fn unchecked_into(self) -> T { match self.failable_into() { Some(value) => value, None => panic!("unchecked conversion failed") } } } /// Implements a failable conversion into u8 from U12. impl FailableInto<u8> for U12 { fn failable_into(self) -> Option<u8> { if self.0 > 0xFF { None } else { Some((self.0 & 0xFF) as u8) } } } /// Implements FailableAs<U12> for the specified type. macro_rules! impl_failable_into_u12 { ($source_type:path) => { impl FailableInto<U12> for $source_type { fn failable_into(self) -> Option<U12> { if self > 0xFFF { None } else { Some(U12(self as u16)) } } } } } impl_failable_into_u12!(u16); impl_failable_into_u12!(u32); impl_failable_into_u12!(u64); impl_failable_into_u12!(usize); // MARK: - Default impl Default for U12 { fn default() -> Self { U12::min_value() } } // MARK: - Arithmetic Operator Traits (Add, Sub, Mul, Div) /// /// Implements an arithmetic trait family for `U12`. This macro generates /// implementations for an arithmetic trait `$trait_name` such that the /// it is possible to invoke `$trait_method` on all of `U12.op(U12)`, `(&'a U12).op(U12)`, /// `U12.op(&'a U12)` and `(&'a U12).op(&'b U12)`. The implementation calls through to /// `$checked_method` on U12. If the `$checked_method` returns `None`, the /// trait panics with the message specified as `$message`. /// macro_rules! impl_arithmetic_trait_family_for_u12 { ($trait_name:ident, $trait_method:ident, $checked_method:ident, $message:expr) => { // Implementation of U12.op(U12) -> U12. impl $trait_name<U12> for U12 { type Output = U12; fn $trait_method(self, other: U12) -> Self::Output { match self.$checked_method(other) { Some(result) => result, None => { panic!($message) } } } } // Implementation of (&'a U12).op(U12) -> U12. impl<'a> $trait_name<U12> for &'a U12 { type Output = U12; fn $trait_method(self, other: U12) -> Self::Output { (*self).$trait_method(other) } } // Implementation of U12.op(&'a U12) -> U12. impl<'a> $trait_name<&'a U12> for U12 { type Output = U12; fn $trait_method(self, other: &'a U12) -> Self::Output { self.$trait_method(*other) } } // Implementation of (&'a U12).op(&'b U12) -> U12. impl<'a,'b> $trait_name<&'a U12> for &'b U12 { type Output = U12; fn $trait_method(self, other: &'a U12) -> Self::Output { (*self).$trait_method(*other) } } } } impl_arithmetic_trait_family_for_u12!(Add, add, checked_add, "arithmetic overflow" ); impl_arithmetic_trait_family_for_u12!(Sub, sub, checked_sub, "arithmetic underflow"); impl_arithmetic_trait_family_for_u12!(Mul, mul, checked_mul, "arithmetic overflow" ); impl_arithmetic_trait_family_for_u12!(Div, div, checked_div, "arithmetic exception"); impl_arithmetic_trait_family_for_u12!(Rem, rem, checked_rem, "arithmetic exception"); // MARK: - Not impl Not for U12 { type Output = U12; fn not(self) -> Self::Output { U12((!self.0) & 0xFFF) } } impl<'a> Not for &'a U12 { type Output = U12; fn not(self) -> Self::Output { (*self).not() } } // MARK: - Bitwise Operations macro_rules! impl_bitwise_trait_family_for_u12 { ($trait_name:ident, $trait_method:ident, $checked_method:ident) => { impl_arithmetic_trait_family_for_u12!($trait_name, $trait_method, $checked_method, "<unreachable>"); } } impl_bitwise_trait_family_for_u12!(BitAnd, bitand, checked_bitand); impl_bitwise_trait_family_for_u12!(BitOr , bitor , checked_bitor ); impl_bitwise_trait_family_for_u12!(BitXor, bitxor, checked_bitxor); // MARK: - Logic Operations /// /// Implements an logic trait family for `U12`. This macro generates /// implementations for an arithmetic trait `$trait_name` such that the /// it is possible to invoke `$trait_method` on all of `U12.op($rhs_type)`, `(&'a U12).op($rhs_type)`, /// `U12.op(&'a $rhs_type)` and `(&'a U12).op(&'b $rhs_type)`. The implementation calls through to /// `$checked_method` on U12. If the RHS value represented as a 64-bit number exceeds /// 12, the implementation panics with the specified `$message`. /// macro_rules! impl_shift_trait_family_for_u12 { ($rhs_type:ident, $trait_name:ident, $trait_method:ident, $checked_method:ident, $message:expr) => { // Implementation of U12.op($rhs_type) -> U12. impl $trait_name<$rhs_type> for U12 { type Output = U12; fn $trait_method(self, other: $rhs_type) -> Self::Output { if (other as u64) > (u32::max_value() as u64) { panic!($message) } else { match self.$checked_method(other as u32) { Some(result) => result, None => { panic!($message) } } } } } // Implementation of (&'a U12).op($rhs_type) -> U12. impl<'a> $trait_name<$rhs_type> for &'a U12 { type Output = U12; fn $trait_method(self, other: $rhs_type) -> Self::Output { (*self).$trait_method(other) } } // Implementation of U12.op(&'a $rhs_type) -> U12. impl<'a> $trait_name<&'a $rhs_type> for U12 { type Output = U12; fn $trait_method(self, other: &'a $rhs_type) -> Self::Output { self.$trait_method(*other) } } // Implementation of (&'a U12).op(&'b $rhs_type) -> U12. impl<'a,'b> $trait_name<&'a $rhs_type> for &'b U12 { type Output = U12; fn $trait_method(self, other: &'a $rhs_type) -> Self::Output { (*self).$trait_method(*other) } } } } // TODO: mm: Implement Shl<U12> impl_shift_trait_family_for_u12!(u8, Shl, shl, checked_shl, "logic overflow"); impl_shift_trait_family_for_u12!(i8, Shl, shl, checked_shl, "logic overflow"); impl_shift_trait_family_for_u12!(u16, Shl, shl, checked_shl, "logic overflow"); impl_shift_trait_family_for_u12!(i16, Shl, shl, checked_shl, "logic overflow"); impl_shift_trait_family_for_u12!(u32, Shl, shl, checked_shl, "logic overflow"); impl_shift_trait_family_for_u12!(i32, Shl, shl, checked_shl, "logic overflow"); impl_shift_trait_family_for_u12!(u64, Shl, shl, checked_shl, "logic overflow"); impl_shift_trait_family_for_u12!(i64, Shl, shl, checked_shl, "logic overflow"); impl_shift_trait_family_for_u12!(usize, Shl, shl, checked_shl, "logic overflow"); impl_shift_trait_family_for_u12!(isize, Shl, shl, checked_shl, "logic overflow"); // TODO: mm: Implement Shr<U12> impl_shift_trait_family_for_u12!(u8, Shr, shr, checked_shr, "logic underflow"); impl_shift_trait_family_for_u12!(i8, Shr, shr, checked_shr, "logic underflow"); impl_shift_trait_family_for_u12!(u16, Shr, shr, checked_shr, "logic underflow"); impl_shift_trait_family_for_u12!(i16, Shr, shr, checked_shr, "logic underflow"); impl_shift_trait_family_for_u12!(u32, Shr, shr, checked_shr, "logic underflow"); impl_shift_trait_family_for_u12!(i32, Shr, shr, checked_shr, "logic underflow"); impl_shift_trait_family_for_u12!(u64, Shr, shr, checked_shr, "logic underflow"); impl_shift_trait_family_for_u12!(i64, Shr, shr, checked_shr, "logic underflow"); impl_shift_trait_family_for_u12!(usize, Shr, shr, checked_shr, "logic underflow"); impl_shift_trait_family_for_u12!(isize, Shr, shr, checked_shr, "logic underflow");