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use crate::num::arithmetic::traits::Sign;
use std::cmp::Ordering;
macro_rules! impl_sign_primitive_int {
($t:ident) => {
impl Sign for $t {
/// Compares a number to zero.
///
/// Returns `Greater`, `Equal`, or `Less`, depending on whether the number is positive,
/// zero, or negative, respectively.
///
/// # Worst-case complexity
/// Constant time and additional memory.
///
/// # Examples
/// See [here](super::sign#sign).
#[inline]
fn sign(&self) -> Ordering {
self.cmp(&0)
}
}
};
}
apply_to_primitive_ints!(impl_sign_primitive_int);
macro_rules! impl_sign_primitive_float {
($t:ident) => {
impl Sign for $t {
/// Compares a number to zero.
///
/// - Positive finite numbers, positive zero, and positive infinity have sign
/// `Greater`.
/// - Negative finite numbers, negative zero, and negative infinity have sign `Less`.
/// - `NaN` has sign `Equal`.
///
/// # Worst-case complexity
/// Constant time and additional memory.
///
/// # Examples
/// See [here](super::sign#sign).
#[inline]
fn sign(&self) -> Ordering {
if self.is_nan() {
Ordering::Equal
} else if self.is_sign_positive() {
Ordering::Greater
} else {
Ordering::Less
}
}
}
};
}
apply_to_primitive_floats!(impl_sign_primitive_float);