traiter 4.0.0

Traits collection.
Documentation
use super::types::Sign;
use super::zeroable::Zeroable;
use core::cmp::Ordering;

pub trait Signed: Zeroable {
    /// Checks if a number is negative.
    /// ```
    /// use traiter::numbers::Signed;
    /// // signed integers
    /// assert!(Signed::is_negative(-1i8));
    /// assert!(!Signed::is_negative(0i8));
    /// assert!(!Signed::is_negative(1i8));
    /// ```
    fn is_negative(self) -> bool;

    /// Checks if a number is positive.
    /// ```
    /// use traiter::numbers::Signed;
    /// // signed integers
    /// assert!(!Signed::is_positive(-1i8));
    /// assert!(!Signed::is_positive(0i8));
    /// assert!(Signed::is_positive(1i8));
    /// ```
    fn is_positive(self) -> bool;

    /// Returns sign of a number.
    /// ```
    /// use traiter::numbers::{Signed, Sign};
    /// // signed integers
    /// assert_eq!(Signed::sign(-1i8), Sign::Negative);
    /// assert_eq!(Signed::sign(0i8), Sign::Zero);
    /// assert_eq!(Signed::sign(1i8), Sign::Positive);
    /// ```
    fn sign(self) -> Sign;
}

macro_rules! signed_integer_impl {
    ($($integer:ty)*) => ($(
        impl Signed for $integer {
            #[inline(always)]
            fn is_negative(self) -> bool {
                <$integer>::is_negative(self)
            }

            #[inline(always)]
            fn is_positive(self) -> bool {
                <$integer>::is_positive(self)
            }

            #[inline(always)]
            fn sign(self) -> Sign {
                match self.cmp(&(0 as $integer)) {
                    Ordering::Equal => Sign::Zero,
                    Ordering::Greater => Sign::Positive,
                    Ordering::Less => Sign::Negative,
                }
            }
        }

        impl Signed for &$integer {
            #[inline(always)]
            fn is_negative(self) -> bool {
                <$integer>::is_negative(*self)
            }

            #[inline(always)]
            fn is_positive(self) -> bool {
                <$integer>::is_positive(*self)
            }

            #[inline(always)]
            fn sign(self) -> Sign {
                match self.cmp(&(0 as $integer)) {
                    Ordering::Equal => Sign::Zero,
                    Ordering::Greater => Sign::Positive,
                    Ordering::Less => Sign::Negative,
                }
            }
        }
    )*)
}

signed_integer_impl!(i8 i16 i32 i64 i128 isize);