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Diffstat (limited to 'vendor/num-traits/src/ops/overflowing.rs')
-rw-r--r-- | vendor/num-traits/src/ops/overflowing.rs | 96 |
1 files changed, 96 insertions, 0 deletions
diff --git a/vendor/num-traits/src/ops/overflowing.rs b/vendor/num-traits/src/ops/overflowing.rs new file mode 100644 index 0000000..c7a35a5 --- /dev/null +++ b/vendor/num-traits/src/ops/overflowing.rs @@ -0,0 +1,96 @@ +use core::ops::{Add, Mul, Sub}; +use core::{i128, i16, i32, i64, i8, isize}; +use core::{u128, u16, u32, u64, u8, usize}; + +macro_rules! overflowing_impl { + ($trait_name:ident, $method:ident, $t:ty) => { + impl $trait_name for $t { + #[inline] + fn $method(&self, v: &Self) -> (Self, bool) { + <$t>::$method(*self, *v) + } + } + }; +} + +/// Performs addition with a flag for overflow. +pub trait OverflowingAdd: Sized + Add<Self, Output = Self> { + /// Returns a tuple of the sum along with a boolean indicating whether an arithmetic overflow would occur. + /// If an overflow would have occurred then the wrapped value is returned. + fn overflowing_add(&self, v: &Self) -> (Self, bool); +} + +overflowing_impl!(OverflowingAdd, overflowing_add, u8); +overflowing_impl!(OverflowingAdd, overflowing_add, u16); +overflowing_impl!(OverflowingAdd, overflowing_add, u32); +overflowing_impl!(OverflowingAdd, overflowing_add, u64); +overflowing_impl!(OverflowingAdd, overflowing_add, usize); +overflowing_impl!(OverflowingAdd, overflowing_add, u128); + +overflowing_impl!(OverflowingAdd, overflowing_add, i8); +overflowing_impl!(OverflowingAdd, overflowing_add, i16); +overflowing_impl!(OverflowingAdd, overflowing_add, i32); +overflowing_impl!(OverflowingAdd, overflowing_add, i64); +overflowing_impl!(OverflowingAdd, overflowing_add, isize); +overflowing_impl!(OverflowingAdd, overflowing_add, i128); + +/// Performs substraction with a flag for overflow. +pub trait OverflowingSub: Sized + Sub<Self, Output = Self> { + /// Returns a tuple of the difference along with a boolean indicating whether an arithmetic overflow would occur. + /// If an overflow would have occurred then the wrapped value is returned. + fn overflowing_sub(&self, v: &Self) -> (Self, bool); +} + +overflowing_impl!(OverflowingSub, overflowing_sub, u8); +overflowing_impl!(OverflowingSub, overflowing_sub, u16); +overflowing_impl!(OverflowingSub, overflowing_sub, u32); +overflowing_impl!(OverflowingSub, overflowing_sub, u64); +overflowing_impl!(OverflowingSub, overflowing_sub, usize); +overflowing_impl!(OverflowingSub, overflowing_sub, u128); + +overflowing_impl!(OverflowingSub, overflowing_sub, i8); +overflowing_impl!(OverflowingSub, overflowing_sub, i16); +overflowing_impl!(OverflowingSub, overflowing_sub, i32); +overflowing_impl!(OverflowingSub, overflowing_sub, i64); +overflowing_impl!(OverflowingSub, overflowing_sub, isize); +overflowing_impl!(OverflowingSub, overflowing_sub, i128); + +/// Performs multiplication with a flag for overflow. +pub trait OverflowingMul: Sized + Mul<Self, Output = Self> { + /// Returns a tuple of the product along with a boolean indicating whether an arithmetic overflow would occur. + /// If an overflow would have occurred then the wrapped value is returned. + fn overflowing_mul(&self, v: &Self) -> (Self, bool); +} + +overflowing_impl!(OverflowingMul, overflowing_mul, u8); +overflowing_impl!(OverflowingMul, overflowing_mul, u16); +overflowing_impl!(OverflowingMul, overflowing_mul, u32); +overflowing_impl!(OverflowingMul, overflowing_mul, u64); +overflowing_impl!(OverflowingMul, overflowing_mul, usize); +overflowing_impl!(OverflowingMul, overflowing_mul, u128); + +overflowing_impl!(OverflowingMul, overflowing_mul, i8); +overflowing_impl!(OverflowingMul, overflowing_mul, i16); +overflowing_impl!(OverflowingMul, overflowing_mul, i32); +overflowing_impl!(OverflowingMul, overflowing_mul, i64); +overflowing_impl!(OverflowingMul, overflowing_mul, isize); +overflowing_impl!(OverflowingMul, overflowing_mul, i128); + +#[test] +fn test_overflowing_traits() { + fn overflowing_add<T: OverflowingAdd>(a: T, b: T) -> (T, bool) { + a.overflowing_add(&b) + } + fn overflowing_sub<T: OverflowingSub>(a: T, b: T) -> (T, bool) { + a.overflowing_sub(&b) + } + fn overflowing_mul<T: OverflowingMul>(a: T, b: T) -> (T, bool) { + a.overflowing_mul(&b) + } + assert_eq!(overflowing_add(5i16, 2), (7, false)); + assert_eq!(overflowing_add(i16::MAX, 1), (i16::MIN, true)); + assert_eq!(overflowing_sub(5i16, 2), (3, false)); + assert_eq!(overflowing_sub(i16::MIN, 1), (i16::MAX, true)); + assert_eq!(overflowing_mul(5i16, 2), (10, false)); + assert_eq!(overflowing_mul(1_000_000_000i32, 10), (1410065408, true)); +} |