Trait std::hash::Hash 1.0.0[−][src]
pub trait Hash {
fn hash<H>(&self, state: &mut H)
where
H: Hasher;
fn hash_slice<H>(data: &[Self], state: &mut H)
where
H: Hasher,
{ ... }
}A hashable type.
Types implementing Hash are able to be hashed with an instance of
Hasher.
Implementing Hash
You can derive Hash with #[derive(Hash)] if all fields implement Hash.
The resulting hash will be the combination of the values from calling
hash on each field.
#[derive(Hash)] struct Rustacean { name: String, country: String, }Run
If you need more control over how a value is hashed, you can of course
implement the Hash trait yourself:
use std::hash::{Hash, Hasher}; struct Person { id: u32, name: String, phone: u64, } impl Hash for Person { fn hash<H: Hasher>(&self, state: &mut H) { self.id.hash(state); self.phone.hash(state); } }Run
Hash and Eq
When implementing both Hash and Eq, it is important that the following
property holds:
k1 == k2 -> hash(k1) == hash(k2)
In other words, if two keys are equal, their hashes must also be equal.
HashMap and HashSet both rely on this behavior.
Thankfully, you won't need to worry about upholding this property when
deriving both Eq and Hash with #[derive(PartialEq, Eq, Hash)].
Required Methods
Provided Methods
fn hash_slice<H>(data: &[Self], state: &mut H) where
H: Hasher, 1.3.0
H: Hasher,
Implementors
impl<Ret, A> Hash for extern "C" fn(A) -> Retimpl<Ret, A> Hash for unsafe fn(A) -> Retimpl<T> Hash for *const T where
T: ?Sized,impl<T> Hash for [T; 31] where
T: Hash,impl<Ret, A, B, C, D, E, F, G, H, I, J, K> Hash for unsafe fn(A, B, C, D, E, F, G, H, I, J, K) -> Retimpl Hash for NonZeroU32impl<Ret, A, B, C, D, E, F> Hash for extern "C" fn(A, B, C, D, E, F, ...) -> Retimpl<T> Hash for [T; 24] where
T: Hash,impl<Ret, A, B, C, D> Hash for extern "C" fn(A, B, C, D, ...) -> Retimpl<Ret, A, B, C, D, E, F, G> Hash for extern "C" fn(A, B, C, D, E, F, G, ...) -> Retimpl<Ret, A, B, C, D, E, F, G, H> Hash for unsafe fn(A, B, C, D, E, F, G, H) -> Retimpl<Ret, A, B, C, D, E, F, G, H, I, J> Hash for unsafe fn(A, B, C, D, E, F, G, H, I, J) -> Retimpl<Ret> Hash for unsafe extern "C" fn() -> Retimpl<Idx> Hash for RangeFrom<Idx> where
Idx: Hash,impl<Ret, A, B, C, D, E> Hash for unsafe extern "C" fn(A, B, C, D, E, ...) -> Retimpl<T> Hash for [T; 10] where
T: Hash,impl<T> Hash for *mut T where
T: ?Sized,impl Hash for isizeimpl<Ret, A, B, C, D, E> Hash for unsafe extern "C" fn(A, B, C, D, E) -> Retimpl Hash for NonZeroUsizeimpl Hash for u16impl<T> Hash for ManuallyDrop<T> where
T: Hash,impl<T> Hash for Option<T> where
T: Hash,impl<Ret, A, B, C, D, E, F, G, H> Hash for fn(A, B, C, D, E, F, G, H) -> Retimpl Hash for Durationimpl<T> Hash for [T; 8] where
T: Hash,impl<Ret, A, B, C, D> Hash for unsafe extern "C" fn(A, B, C, D) -> Retimpl<Ret, A, B, C, D, E, F, G, H, I> Hash for unsafe fn(A, B, C, D, E, F, G, H, I) -> Retimpl<Ret, A> Hash for fn(A) -> Retimpl Hash for u128impl<T> Hash for Wrapping<T> where
T: Hash,impl<Ret, A, B, C, D, E, F, G, H, I, J, K> Hash for fn(A, B, C, D, E, F, G, H, I, J, K) -> Retimpl<T> Hash for [T; 1] where
T: Hash,impl<Ret, A, B, C, D, E, F> Hash for extern "C" fn(A, B, C, D, E, F) -> Retimpl Hash for Orderingimpl<Ret, A, B> Hash for unsafe extern "C" fn(A, B, ...) -> Retimpl Hash for i64impl Hash for u8impl<Ret, A, B, C, D> Hash for unsafe fn(A, B, C, D) -> Retimpl<Ret, A, B, C, D, E, F, G> Hash for extern "C" fn(A, B, C, D, E, F, G) -> Retimpl Hash for !impl<Ret, A, B, C, D, E, F, G, H, I, J, K> Hash for extern "C" fn(A, B, C, D, E, F, G, H, I, J, K, ...) -> Retimpl<A, B, C, D, E, F, G, H, I> Hash for (A, B, C, D, E, F, G, H, I) where
A: Hash,
B: Hash,
C: Hash,
D: Hash,
E: Hash,
F: Hash,
G: Hash,
H: Hash,
I: Hash + ?Sized,impl<Ret, A, B, C, D> Hash for extern "C" fn(A, B, C, D) -> Retimpl<A, B, C, D, E, F> Hash for (A, B, C, D, E, F) where
A: Hash,
B: Hash,
C: Hash,
D: Hash,
E: Hash,
F: Hash + ?Sized,impl<T> Hash for [T; 25] where
T: Hash,impl<Ret, A, B, C, D> Hash for unsafe extern "C" fn(A, B, C, D, ...) -> Retimpl Hash for Pinnedimpl Hash for Errorimpl<Ret, A, B, C, D, E, F, G, H> Hash for extern "C" fn(A, B, C, D, E, F, G, H, ...) -> Retimpl<Ret> Hash for fn() -> Retimpl<T> Hash for [T; 15] where
T: Hash,impl Hash for i8impl<Ret, A, B, C, D, E> Hash for unsafe fn(A, B, C, D, E) -> Retimpl<Ret, A, B, C, D, E, F, G, H> Hash for unsafe extern "C" fn(A, B, C, D, E, F, G, H) -> Retimpl<Ret, A, B, C, D, E, F, G> Hash for unsafe fn(A, B, C, D, E, F, G) -> Retimpl<T> Hash for [T; 30] where
T: Hash,impl Hash for TypeIdimpl<Ret, A, B, C, D, E, F, G, H, I> Hash for extern "C" fn(A, B, C, D, E, F, G, H, I) -> Retimpl Hash for strimpl<Ret, A, B, C, D, E, F, G, H> Hash for extern "C" fn(A, B, C, D, E, F, G, H) -> Retimpl<Ret, A, B, C, D, E> Hash for extern "C" fn(A, B, C, D, E) -> Retimpl<Ret, A, B, C> Hash for unsafe fn(A, B, C) -> Retimpl<T> Hash for Reverse<T> where
T: Hash,impl<Ret> Hash for extern "C" fn() -> Retimpl Hash for NonZeroU64impl<T> Hash for [T; 21] where
T: Hash,impl<Idx> Hash for RangeToInclusive<Idx> where
Idx: Hash,impl<T> Hash for Bound<T> where
T: Hash,impl<Ret, A, B, C, D, E, F, G, H, I, J, K> Hash for unsafe extern "C" fn(A, B, C, D, E, F, G, H, I, J, K, ...) -> Retimpl<T> Hash for [T] where
T: Hash,impl<T> Hash for [T; 9] where
T: Hash,impl<Ret, A, B, C, D, E, F, G, H, I> Hash for fn(A, B, C, D, E, F, G, H, I) -> Retimpl<T> Hash for [T; 2] where
T: Hash,impl<Ret, A, B, C, D, E, F, G, H, I> Hash for unsafe extern "C" fn(A, B, C, D, E, F, G, H, I) -> Retimpl<Ret, A, B, C, D, E, F, G, H, I, J> Hash for extern "C" fn(A, B, C, D, E, F, G, H, I, J, ...) -> Retimpl<T> Hash for PhantomData<T> where
T: ?Sized,impl<Ret, A, B, C, D, E, F> Hash for unsafe extern "C" fn(A, B, C, D, E, F) -> Retimpl<Idx> Hash for Range<Idx> where
Idx: Hash,impl<T> Hash for [T; 0] where
T: Hash,impl<Ret, A, B, C, D, E, F, G> Hash for unsafe extern "C" fn(A, B, C, D, E, F, G, ...) -> Retimpl<T> Hash for [T; 27] where
T: Hash,impl Hash for i16impl<T> Hash for [T; 14] where
T: Hash,impl<T> Hash for [T; 32] where
T: Hash,impl<T> Hash for [T; 16] where
T: Hash,impl<T> Hash for [T; 28] where
T: Hash,impl<'a, T> Hash for &'a T where
T: Hash + ?Sized,impl<Ret, A, B, C, D, E, F, G, H, I, J, K, L> Hash for extern "C" fn(A, B, C, D, E, F, G, H, I, J, K, L, ...) -> Retimpl<T> Hash for [T; 23] where
T: Hash,impl<Ret, A, B> Hash for unsafe fn(A, B) -> Retimpl<Ret, A, B, C, D, E, F, G, H, I, J> Hash for extern "C" fn(A, B, C, D, E, F, G, H, I, J) -> Retimpl<Ret, A, B> Hash for extern "C" fn(A, B, ...) -> Retimpl<Ret, A, B, C> Hash for fn(A, B, C) -> Retimpl<T> Hash for [T; 18] where
T: Hash,impl Hash for NonZeroU8impl<Ret, A, B, C, D, E, F, G, H, I, J> Hash for unsafe extern "C" fn(A, B, C, D, E, F, G, H, I, J) -> Retimpl<Ret, A, B> Hash for extern "C" fn(A, B) -> Retimpl Hash for ()impl<T> Hash for [T; 26] where
T: Hash,impl<A, B, C, D, E, F, G> Hash for (A, B, C, D, E, F, G) where
A: Hash,
B: Hash,
C: Hash,
D: Hash,
E: Hash,
F: Hash,
G: Hash + ?Sized,impl<T> Hash for Discriminant<T>impl<Ret, A, B, C, D, E, F, G, H> Hash for unsafe extern "C" fn(A, B, C, D, E, F, G, H, ...) -> Retimpl<Ret, A, B, C, D, E, F, G, H, I, J, K> Hash for extern "C" fn(A, B, C, D, E, F, G, H, I, J, K) -> Retimpl<A, B, C, D> Hash for (A, B, C, D) where
A: Hash,
B: Hash,
C: Hash,
D: Hash + ?Sized,impl<Ret, A> Hash for extern "C" fn(A, ...) -> Retimpl Hash for NonZeroU16impl<T, E> Hash for Result<T, E> where
E: Hash,
T: Hash,impl<T> Hash for [T; 4] where
T: Hash,impl<Ret, A, B> Hash for unsafe extern "C" fn(A, B) -> Retimpl<T> Hash for [T; 29] where
T: Hash,impl<Ret, A, B, C, D, E, F, G> Hash for unsafe extern "C" fn(A, B, C, D, E, F, G) -> Retimpl<Ret, A, B, C, D, E, F, G, H, I, J, K> Hash for unsafe extern "C" fn(A, B, C, D, E, F, G, H, I, J, K) -> Retimpl Hash for u64impl<Ret, A, B, C, D, E, F, G, H, I, J> Hash for unsafe extern "C" fn(A, B, C, D, E, F, G, H, I, J, ...) -> Retimpl<Ret> Hash for unsafe fn() -> Retimpl<Ret, A, B, C, D, E, F, G> Hash for fn(A, B, C, D, E, F, G) -> Retimpl<T> Hash for [T; 3] where
T: Hash,impl<Ret, A, B, C, D, E, F, G, H, I, J, K, L> Hash for fn(A, B, C, D, E, F, G, H, I, J, K, L) -> Retimpl<T> Hash for [T; 22] where
T: Hash,impl Hash for RangeFullimpl<A, B, C, D, E, F, G, H, I, J, K, L> Hash for (A, B, C, D, E, F, G, H, I, J, K, L) where
A: Hash,
B: Hash,
C: Hash,
D: Hash,
E: Hash,
F: Hash,
G: Hash,
H: Hash,
I: Hash,
J: Hash,
K: Hash,
L: Hash + ?Sized,impl Hash for usizeimpl<Ret, A, B, C, D, E, F, G, H, I, J> Hash for fn(A, B, C, D, E, F, G, H, I, J) -> Retimpl<A, B, C, D, E, F, G, H, I, J> Hash for (A, B, C, D, E, F, G, H, I, J) where
A: Hash,
B: Hash,
C: Hash,
D: Hash,
E: Hash,
F: Hash,
G: Hash,
H: Hash,
I: Hash,
J: Hash + ?Sized,impl<T> Hash for [T; 11] where
T: Hash,impl<Idx> Hash for RangeInclusive<Idx> where
Idx: Hash,impl<Ret, A, B, C, D, E, F, G, H, I, J, K, L> Hash for unsafe extern "C" fn(A, B, C, D, E, F, G, H, I, J, K, L) -> Retimpl Hash for NoneErrorimpl<Ret, A, B, C, D, E> Hash for fn(A, B, C, D, E) -> Retimpl<Ret, A, B, C, D, E, F> Hash for unsafe fn(A, B, C, D, E, F) -> Retimpl<Ret, A> Hash for unsafe extern "C" fn(A) -> Retimpl<Ret, A, B, C, D, E, F, G, H, I> Hash for extern "C" fn(A, B, C, D, E, F, G, H, I, ...) -> Retimpl<'a, T> Hash for &'a mut T where
T: Hash + ?Sized,impl<T> Hash for NonNull<T> where
T: ?Sized,impl<A, B, C, D, E, F, G, H> Hash for (A, B, C, D, E, F, G, H) where
A: Hash,
B: Hash,
C: Hash,
D: Hash,
E: Hash,
F: Hash,
G: Hash,
H: Hash + ?Sized,impl<T> Hash for Poll<T> where
T: Hash,impl<A, B, C> Hash for (A, B, C) where
A: Hash,
B: Hash,
C: Hash + ?Sized,impl<A, B> Hash for (A, B) where
A: Hash,
B: Hash + ?Sized,impl<Idx> Hash for RangeTo<Idx> where
Idx: Hash,impl<A> Hash for (A,) where
A: Hash + ?Sized,impl Hash for charimpl<T> Hash for [T; 7] where
T: Hash,impl<T> Hash for [T; 12] where
T: Hash,impl<Ret, A, B, C, D> Hash for fn(A, B, C, D) -> Retimpl<Ret, A, B, C> Hash for unsafe extern "C" fn(A, B, C, ...) -> Retimpl<Ret, A, B, C> Hash for extern "C" fn(A, B, C, ...) -> Retimpl<Ret, A, B, C, D, E> Hash for extern "C" fn(A, B, C, D, E, ...) -> Retimpl<T> Hash for [T; 5] where
T: Hash,impl<Y, R> Hash for GeneratorState<Y, R> where
R: Hash,
Y: Hash,impl Hash for boolimpl<T> Hash for [T; 13] where
T: Hash,impl Hash for i32impl Hash for u32impl<T> Hash for [T; 20] where
T: Hash,impl<Ret, A, B, C, D, E, F, G, H, I> Hash for unsafe extern "C" fn(A, B, C, D, E, F, G, H, I, ...) -> Retimpl Hash for i128impl<Ret, A, B, C, D, E, F> Hash for unsafe extern "C" fn(A, B, C, D, E, F, ...) -> Retimpl<Ret, A, B, C, D, E, F> Hash for fn(A, B, C, D, E, F) -> Retimpl<Ret, A, B> Hash for fn(A, B) -> Retimpl<Ret, A, B, C> Hash for unsafe extern "C" fn(A, B, C) -> Retimpl Hash for NonZeroU128impl<A, B, C, D, E> Hash for (A, B, C, D, E) where
A: Hash,
B: Hash,
C: Hash,
D: Hash,
E: Hash + ?Sized,impl<Ret, A, B, C, D, E, F, G, H, I, J, K, L> Hash for extern "C" fn(A, B, C, D, E, F, G, H, I, J, K, L) -> Retimpl<T> Hash for [T; 19] where
T: Hash,impl<Ret, A, B, C, D, E, F, G, H, I, J, K, L> Hash for unsafe fn(A, B, C, D, E, F, G, H, I, J, K, L) -> Retimpl<Ret, A> Hash for unsafe extern "C" fn(A, ...) -> Retimpl<Ret, A, B, C> Hash for extern "C" fn(A, B, C) -> Retimpl<T> Hash for [T; 6] where
T: Hash,impl<T> Hash for [T; 17] where
T: Hash,impl<A, B, C, D, E, F, G, H, I, J, K> Hash for (A, B, C, D, E, F, G, H, I, J, K) where
A: Hash,
B: Hash,
C: Hash,
D: Hash,
E: Hash,
F: Hash,
G: Hash,
H: Hash,
I: Hash,
J: Hash,
K: Hash + ?Sized,impl<Ret, A, B, C, D, E, F, G, H, I, J, K, L> Hash for unsafe extern "C" fn(A, B, C, D, E, F, G, H, I, J, K, L, ...) -> Retimpl<'a, B> Hash for Cow<'a, B> where
B: Hash + ToOwned + ?Sized,impl<T> Hash for Arc<T> where
T: Hash + ?Sized,impl<A> Hash for VecDeque<A> where
A: Hash,impl<T> Hash for BTreeSet<T> where
T: Hash,impl<T> Hash for Vec<T> where
T: Hash,impl Hash for Stringimpl<T> Hash for LinkedList<T> where
T: Hash,impl<T> Hash for Rc<T> where
T: Hash + ?Sized,impl<T> Hash for Box<T> where
T: Hash + ?Sized,impl<K, V> Hash for BTreeMap<K, V> where
K: Hash,
V: Hash,impl Hash for ThreadIdimpl Hash for CStringimpl Hash for CStrimpl Hash for OsStringimpl Hash for OsStrimpl Hash for FileTypeimpl Hash for ErrorKindimpl Hash for IpAddrimpl Hash for Ipv6MulticastScopeimpl Hash for Ipv4Addrimpl Hash for Ipv6Addrimpl Hash for SocketAddrimpl Hash for SocketAddrV4impl Hash for SocketAddrV6impl<'a> Hash for Prefix<'a>impl<'a> Hash for PrefixComponent<'a>impl<'a> Hash for Component<'a>impl Hash for PathBufimpl Hash for Pathimpl Hash for Instantimpl Hash for SystemTime