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Diffstat (limited to 'vendor/num-traits/src/ops/checked.rs')
| -rw-r--r-- | vendor/num-traits/src/ops/checked.rs | 261 |
1 files changed, 261 insertions, 0 deletions
diff --git a/vendor/num-traits/src/ops/checked.rs b/vendor/num-traits/src/ops/checked.rs new file mode 100644 index 0000000..da1eb3e --- /dev/null +++ b/vendor/num-traits/src/ops/checked.rs @@ -0,0 +1,261 @@ +use core::ops::{Add, Div, Mul, Rem, Shl, Shr, Sub}; + +/// Performs addition that returns `None` instead of wrapping around on +/// overflow. +pub trait CheckedAdd: Sized + Add<Self, Output = Self> { + /// Adds two numbers, checking for overflow. If overflow happens, `None` is + /// returned. + fn checked_add(&self, v: &Self) -> Option<Self>; +} + +macro_rules! checked_impl { + ($trait_name:ident, $method:ident, $t:ty) => { + impl $trait_name for $t { + #[inline] + fn $method(&self, v: &$t) -> Option<$t> { + <$t>::$method(*self, *v) + } + } + }; +} + +checked_impl!(CheckedAdd, checked_add, u8); +checked_impl!(CheckedAdd, checked_add, u16); +checked_impl!(CheckedAdd, checked_add, u32); +checked_impl!(CheckedAdd, checked_add, u64); +checked_impl!(CheckedAdd, checked_add, usize); +checked_impl!(CheckedAdd, checked_add, u128); + +checked_impl!(CheckedAdd, checked_add, i8); +checked_impl!(CheckedAdd, checked_add, i16); +checked_impl!(CheckedAdd, checked_add, i32); +checked_impl!(CheckedAdd, checked_add, i64); +checked_impl!(CheckedAdd, checked_add, isize); +checked_impl!(CheckedAdd, checked_add, i128); + +/// Performs subtraction that returns `None` instead of wrapping around on underflow. +pub trait CheckedSub: Sized + Sub<Self, Output = Self> { + /// Subtracts two numbers, checking for underflow. If underflow happens, + /// `None` is returned. + fn checked_sub(&self, v: &Self) -> Option<Self>; +} + +checked_impl!(CheckedSub, checked_sub, u8); +checked_impl!(CheckedSub, checked_sub, u16); +checked_impl!(CheckedSub, checked_sub, u32); +checked_impl!(CheckedSub, checked_sub, u64); +checked_impl!(CheckedSub, checked_sub, usize); +checked_impl!(CheckedSub, checked_sub, u128); + +checked_impl!(CheckedSub, checked_sub, i8); +checked_impl!(CheckedSub, checked_sub, i16); +checked_impl!(CheckedSub, checked_sub, i32); +checked_impl!(CheckedSub, checked_sub, i64); +checked_impl!(CheckedSub, checked_sub, isize); +checked_impl!(CheckedSub, checked_sub, i128); + +/// Performs multiplication that returns `None` instead of wrapping around on underflow or +/// overflow. +pub trait CheckedMul: Sized + Mul<Self, Output = Self> { + /// Multiplies two numbers, checking for underflow or overflow. If underflow + /// or overflow happens, `None` is returned. + fn checked_mul(&self, v: &Self) -> Option<Self>; +} + +checked_impl!(CheckedMul, checked_mul, u8); +checked_impl!(CheckedMul, checked_mul, u16); +checked_impl!(CheckedMul, checked_mul, u32); +checked_impl!(CheckedMul, checked_mul, u64); +checked_impl!(CheckedMul, checked_mul, usize); +checked_impl!(CheckedMul, checked_mul, u128); + +checked_impl!(CheckedMul, checked_mul, i8); +checked_impl!(CheckedMul, checked_mul, i16); +checked_impl!(CheckedMul, checked_mul, i32); +checked_impl!(CheckedMul, checked_mul, i64); +checked_impl!(CheckedMul, checked_mul, isize); +checked_impl!(CheckedMul, checked_mul, i128); + +/// Performs division that returns `None` instead of panicking on division by zero and instead of +/// wrapping around on underflow and overflow. +pub trait CheckedDiv: Sized + Div<Self, Output = Self> { + /// Divides two numbers, checking for underflow, overflow and division by + /// zero. If any of that happens, `None` is returned. + fn checked_div(&self, v: &Self) -> Option<Self>; +} + +checked_impl!(CheckedDiv, checked_div, u8); +checked_impl!(CheckedDiv, checked_div, u16); +checked_impl!(CheckedDiv, checked_div, u32); +checked_impl!(CheckedDiv, checked_div, u64); +checked_impl!(CheckedDiv, checked_div, usize); +checked_impl!(CheckedDiv, checked_div, u128); + +checked_impl!(CheckedDiv, checked_div, i8); +checked_impl!(CheckedDiv, checked_div, i16); +checked_impl!(CheckedDiv, checked_div, i32); +checked_impl!(CheckedDiv, checked_div, i64); +checked_impl!(CheckedDiv, checked_div, isize); +checked_impl!(CheckedDiv, checked_div, i128); + +/// Performs an integral remainder that returns `None` instead of panicking on division by zero and +/// instead of wrapping around on underflow and overflow. +pub trait CheckedRem: Sized + Rem<Self, Output = Self> { + /// Finds the remainder of dividing two numbers, checking for underflow, overflow and division + /// by zero. If any of that happens, `None` is returned. + /// + /// # Examples + /// + /// ``` + /// use num_traits::CheckedRem; + /// use std::i32::MIN; + /// + /// assert_eq!(CheckedRem::checked_rem(&10, &7), Some(3)); + /// assert_eq!(CheckedRem::checked_rem(&10, &-7), Some(3)); + /// assert_eq!(CheckedRem::checked_rem(&-10, &7), Some(-3)); + /// assert_eq!(CheckedRem::checked_rem(&-10, &-7), Some(-3)); + /// + /// assert_eq!(CheckedRem::checked_rem(&10, &0), None); + /// + /// assert_eq!(CheckedRem::checked_rem(&MIN, &1), Some(0)); + /// assert_eq!(CheckedRem::checked_rem(&MIN, &-1), None); + /// ``` + fn checked_rem(&self, v: &Self) -> Option<Self>; +} + +checked_impl!(CheckedRem, checked_rem, u8); +checked_impl!(CheckedRem, checked_rem, u16); +checked_impl!(CheckedRem, checked_rem, u32); +checked_impl!(CheckedRem, checked_rem, u64); +checked_impl!(CheckedRem, checked_rem, usize); +checked_impl!(CheckedRem, checked_rem, u128); + +checked_impl!(CheckedRem, checked_rem, i8); +checked_impl!(CheckedRem, checked_rem, i16); +checked_impl!(CheckedRem, checked_rem, i32); +checked_impl!(CheckedRem, checked_rem, i64); +checked_impl!(CheckedRem, checked_rem, isize); +checked_impl!(CheckedRem, checked_rem, i128); + +macro_rules! checked_impl_unary { + ($trait_name:ident, $method:ident, $t:ty) => { + impl $trait_name for $t { + #[inline] + fn $method(&self) -> Option<$t> { + <$t>::$method(*self) + } + } + }; +} + +/// Performs negation that returns `None` if the result can't be represented. +pub trait CheckedNeg: Sized { + /// Negates a number, returning `None` for results that can't be represented, like signed `MIN` + /// values that can't be positive, or non-zero unsigned values that can't be negative. + /// + /// # Examples + /// + /// ``` + /// use num_traits::CheckedNeg; + /// use std::i32::MIN; + /// + /// assert_eq!(CheckedNeg::checked_neg(&1_i32), Some(-1)); + /// assert_eq!(CheckedNeg::checked_neg(&-1_i32), Some(1)); + /// assert_eq!(CheckedNeg::checked_neg(&MIN), None); + /// + /// assert_eq!(CheckedNeg::checked_neg(&0_u32), Some(0)); + /// assert_eq!(CheckedNeg::checked_neg(&1_u32), None); + /// ``` + fn checked_neg(&self) -> Option<Self>; +} + +checked_impl_unary!(CheckedNeg, checked_neg, u8); +checked_impl_unary!(CheckedNeg, checked_neg, u16); +checked_impl_unary!(CheckedNeg, checked_neg, u32); +checked_impl_unary!(CheckedNeg, checked_neg, u64); +checked_impl_unary!(CheckedNeg, checked_neg, usize); +checked_impl_unary!(CheckedNeg, checked_neg, u128); + +checked_impl_unary!(CheckedNeg, checked_neg, i8); +checked_impl_unary!(CheckedNeg, checked_neg, i16); +checked_impl_unary!(CheckedNeg, checked_neg, i32); +checked_impl_unary!(CheckedNeg, checked_neg, i64); +checked_impl_unary!(CheckedNeg, checked_neg, isize); +checked_impl_unary!(CheckedNeg, checked_neg, i128); + +/// Performs a left shift that returns `None` on shifts larger than +/// or equal to the type width. +pub trait CheckedShl: Sized + Shl<u32, Output = Self> { + /// Checked shift left. Computes `self << rhs`, returning `None` + /// if `rhs` is larger than or equal to the number of bits in `self`. + /// + /// ``` + /// use num_traits::CheckedShl; + /// + /// let x: u16 = 0x0001; + /// + /// assert_eq!(CheckedShl::checked_shl(&x, 0), Some(0x0001)); + /// assert_eq!(CheckedShl::checked_shl(&x, 1), Some(0x0002)); + /// assert_eq!(CheckedShl::checked_shl(&x, 15), Some(0x8000)); + /// assert_eq!(CheckedShl::checked_shl(&x, 16), None); + /// ``` + fn checked_shl(&self, rhs: u32) -> Option<Self>; +} + +macro_rules! checked_shift_impl { + ($trait_name:ident, $method:ident, $t:ty) => { + impl $trait_name for $t { + #[inline] + fn $method(&self, rhs: u32) -> Option<$t> { + <$t>::$method(*self, rhs) + } + } + }; +} + +checked_shift_impl!(CheckedShl, checked_shl, u8); +checked_shift_impl!(CheckedShl, checked_shl, u16); +checked_shift_impl!(CheckedShl, checked_shl, u32); +checked_shift_impl!(CheckedShl, checked_shl, u64); +checked_shift_impl!(CheckedShl, checked_shl, usize); +checked_shift_impl!(CheckedShl, checked_shl, u128); + +checked_shift_impl!(CheckedShl, checked_shl, i8); +checked_shift_impl!(CheckedShl, checked_shl, i16); +checked_shift_impl!(CheckedShl, checked_shl, i32); +checked_shift_impl!(CheckedShl, checked_shl, i64); +checked_shift_impl!(CheckedShl, checked_shl, isize); +checked_shift_impl!(CheckedShl, checked_shl, i128); + +/// Performs a right shift that returns `None` on shifts larger than +/// or equal to the type width. +pub trait CheckedShr: Sized + Shr<u32, Output = Self> { + /// Checked shift right. Computes `self >> rhs`, returning `None` + /// if `rhs` is larger than or equal to the number of bits in `self`. + /// + /// ``` + /// use num_traits::CheckedShr; + /// + /// let x: u16 = 0x8000; + /// + /// assert_eq!(CheckedShr::checked_shr(&x, 0), Some(0x8000)); + /// assert_eq!(CheckedShr::checked_shr(&x, 1), Some(0x4000)); + /// assert_eq!(CheckedShr::checked_shr(&x, 15), Some(0x0001)); + /// assert_eq!(CheckedShr::checked_shr(&x, 16), None); + /// ``` + fn checked_shr(&self, rhs: u32) -> Option<Self>; +} + +checked_shift_impl!(CheckedShr, checked_shr, u8); +checked_shift_impl!(CheckedShr, checked_shr, u16); +checked_shift_impl!(CheckedShr, checked_shr, u32); +checked_shift_impl!(CheckedShr, checked_shr, u64); +checked_shift_impl!(CheckedShr, checked_shr, usize); +checked_shift_impl!(CheckedShr, checked_shr, u128); + +checked_shift_impl!(CheckedShr, checked_shr, i8); +checked_shift_impl!(CheckedShr, checked_shr, i16); +checked_shift_impl!(CheckedShr, checked_shr, i32); +checked_shift_impl!(CheckedShr, checked_shr, i64); +checked_shift_impl!(CheckedShr, checked_shr, isize); +checked_shift_impl!(CheckedShr, checked_shr, i128); |