bjoernager/rust
bjoernager/rust
1
Fork 0
Code Activity

Implement signum with Ord

Browse source
This commit is contained in:
Scott McMurray 2023-01-12 22:39:25 -08:00
parent bfffe406fb
commit fcbc12eae3
1 changed files with 6 additions and 5 deletions
Download patch file Download diff file Expand all files Collapse all files

11
library/core/src/num/int_macros.rs
View file

@ -2574,12 +2574,13 @@ macro_rules! int_impl {
#[must_use = "this returns the result of the operation, \ #[must_use = "this returns the result of the operation, \
without modifying the original"] without modifying the original"]
#[inline(always)] #[inline(always)]
#[rustc_allow_const_fn_unstable(const_cmp)]
pub const fn signum(self) -> Self { pub const fn signum(self) -> Self {
match self { // Picking the right way to phrase this is complicated
n if n > 0 => 1, // (<https://graphics.stanford.edu/~seander/bithacks.html#CopyIntegerSign>)
0 => 0, // so delegate it to `Ord` which is already producing -1/0/+1
_ => -1, // exactly like we need and can be the place to deal with the complexity.
} self.cmp(&0) as _
} }
/// Returns `true` if `self` is positive and `false` if the number is zero or /// Returns `true` if `self` is positive and `false` if the number is zero or