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refactor: implement Deref for ReverseOrdOption

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This commit is contained in:
Matouš Volf 2024-09-10 16:12:14 +02:00
parent c3c4d70aad
commit 7d6aac3882
1 changed files with 10 additions and 2 deletions
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12
src/utils/reverse_ord_option.rs
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@ -1,10 +1,18 @@
use std::cmp::Ordering;
use std::ops::Deref;
/* The default ordering of `Option`s is `None` being less than `Some`. The purpose of this struct is
to reverse that. */
#[derive(PartialEq)]
pub(crate) struct ReverseOrdOption<'a, T>(&'a Option<T>);
impl<'a, T> Deref for ReverseOrdOption<'a, T> {
type Target = Option<T>;
fn deref(&self) -> &Self::Target {
self.0
}
}
impl<'a, T: Ord> Eq for ReverseOrdOption<'a, T> {}
impl<'a, T: Ord> PartialOrd<Self> for ReverseOrdOption<'a, T> {
@ -15,7 +23,7 @@ impl<'a, T: Ord> PartialOrd<Self> for ReverseOrdOption<'a, T> {
impl<'a, T: Ord> Ord for ReverseOrdOption<'a, T> {
fn cmp(&self, other: &Self) -> Ordering {
match (self.0.as_ref(), other.0.as_ref()) {
match (self.as_ref(), other.as_ref()) {
(None, None) => Ordering::Equal,
(None, Some(_)) => Ordering::Greater,
(Some(_), None) => Ordering::Less,