ncollide3d/utils/
hashable_partial_eq.rs

1use crate::utils::AsBytes;
2use std::hash::{Hash, Hasher};
3
4/// A structure that implements `Eq` and is hashable even if the wrapped data implements only
5/// `PartialEq`.
6#[derive(PartialEq, Clone, Debug)]
7pub struct HashablePartialEq<T> {
8    value: T,
9}
10
11impl<T> HashablePartialEq<T> {
12    /// Creates a new `HashablePartialEq`. This is unsafe because you must be sure that you really
13    /// want to transform the wrapped object's partial equality to an equivalence relation.
14    pub unsafe fn new(value: T) -> HashablePartialEq<T> {
15        HashablePartialEq { value: value }
16    }
17
18    /// Gets the wrapped value.
19    pub fn unwrap(self) -> T {
20        self.value
21    }
22}
23
24impl<T: PartialEq> Eq for HashablePartialEq<T> {}
25
26impl<T: AsBytes> Hash for HashablePartialEq<T> {
27    #[inline]
28    fn hash<H: Hasher>(&self, state: &mut H) {
29        state.write(self.value.as_bytes())
30    }
31}