1.0.0[][src]Trait sp_std::hash::Hash

pub trait Hash {
    pub fn hash<H>(&self, state: &mut H)
    where
        H: Hasher
; pub 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,
}

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);
    }
}

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

pub fn hash<H>(&self, state: &mut H) where
    H: Hasher
[src]

Feeds this value into the given Hasher.

Examples

use std::collections::hash_map::DefaultHasher;
use std::hash::{Hash, Hasher};

let mut hasher = DefaultHasher::new();
7920.hash(&mut hasher);
println!("Hash is {:x}!", hasher.finish());
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Provided methods

pub fn hash_slice<H>(data: &[Self], state: &mut H) where
    H: Hasher
1.3.0[src]

Feeds a slice of this type into the given Hasher.

Examples

use std::collections::hash_map::DefaultHasher;
use std::hash::{Hash, Hasher};

let mut hasher = DefaultHasher::new();
let numbers = [6, 28, 496, 8128];
Hash::hash_slice(&numbers, &mut hasher);
println!("Hash is {:x}!", hasher.finish());
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Implementations on Foreign Types

impl Hash for SystemTime[src]

impl Hash for Ipv6Addr[src]

impl Hash for SocketAddrV6[src]

impl Hash for Path[src]

impl Hash for SocketAddr[src]

impl Hash for PathBuf[src]

impl<'a> Hash for Component<'a>[src]

impl Hash for Instant[src]

impl Hash for Ipv4Addr[src]

impl Hash for ThreadId[src]

impl Hash for ErrorKind[src]

impl Hash for FileType[src]

impl Hash for CStr[src]

impl Hash for CString[src]

impl Hash for UCred[src]

impl Hash for Ipv6MulticastScope[src]

impl Hash for OsStr[src]

impl Hash for OsString[src]

impl Hash for IpAddr[src]

impl Hash for SocketAddrV4[src]

impl<'_> Hash for PrefixComponent<'_>[src]

impl<'a> Hash for Prefix<'a>[src]

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) -> Ret[src]

impl<Ret, A, B> Hash for extern "C" fn(A, B) -> Ret[src]

impl<A, B, C> Hash for (A, B, C) where
    C: Hash + ?Sized,
    A: Hash,
    B: Hash
[src]

impl Hash for bool[src]

impl<Ret, A, B, C, D, E, F, G, H> Hash for unsafe fn(A, B, C, D, E, F, G, H) -> Ret[src]

impl Hash for u32[src]

impl<Ret, A, B> Hash for extern "C" fn(A, B, ...) -> Ret[src]

impl<Ret, A, B, C, D, E> Hash for unsafe extern "C" fn(A, B, C, D, E) -> Ret[src]

impl<T> Hash for *mut T where
    T: ?Sized
[src]

impl<Ret, A> Hash for extern "C" fn(A) -> Ret[src]

impl<A, B> Hash for (A, B) where
    A: Hash,
    B: Hash + ?Sized
[src]

impl<Ret, A, B, C, D, E, F> Hash for extern "C" fn(A, B, C, D, E, F, ...) -> Ret[src]

impl Hash for u8[src]

impl Hash for usize[src]

impl<Ret, A, B, C> Hash for fn(A, B, C) -> Ret[src]

impl<Ret, A, B, C, D, E, F, G> Hash for unsafe fn(A, B, C, D, E, F, G) -> Ret[src]

impl<Ret, A, B, C, D, E, F, G> Hash for fn(A, B, C, D, E, F, G) -> Ret[src]

impl<Ret, A, B, C, D, E, F> Hash for unsafe extern "C" fn(A, B, C, D, E, F) -> Ret[src]

impl<Ret, A, B, C, D, E, F, G, H, I> Hash for fn(A, B, C, D, E, F, G, H, I) -> Ret[src]

impl<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
    C: Hash,
    A: Hash,
    E: Hash,
    K: Hash,
    F: Hash,
    I: Hash,
    B: Hash,
    H: Hash,
    D: Hash,
    G: Hash,
    J: Hash,
    L: Hash + ?Sized
[src]

impl<T> Hash for [T] where
    T: Hash
[src]

impl<Ret, A, B, C> Hash for extern "C" fn(A, B, C, ...) -> Ret[src]

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, ...) -> Ret[src]

impl<Ret, A, B, C, D> Hash for unsafe extern "C" fn(A, B, C, D, ...) -> Ret[src]

impl<Ret, A, B, C, D, E, F, G, H> Hash for fn(A, B, C, D, E, F, G, H) -> Ret[src]

impl<Ret, A, B, C, D> Hash for fn(A, B, C, D) -> Ret[src]

impl Hash for str[src]

impl<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, ...) -> Ret[src]

impl<Ret, A, B, C, D, E, F> Hash for unsafe extern "C" fn(A, B, C, D, E, F, ...) -> Ret[src]

impl<T> Hash for Poll<T> where
    T: Hash
[src]

impl<Ret, A, B, C> Hash for extern "C" fn(A, B, C) -> Ret[src]

impl Hash for ()[src]

impl<A, B, C, D, E, F, G> Hash for (A, B, C, D, E, F, G) where
    C: Hash,
    A: Hash,
    E: Hash,
    F: Hash,
    B: Hash,
    D: Hash,
    G: Hash + ?Sized
[src]

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) -> Ret[src]

impl<Ret, A, B, C, D, E, F, G, H, I> Hash for unsafe fn(A, B, C, D, E, F, G, H, I) -> Ret[src]

impl<A, B, C, D> Hash for (A, B, C, D) where
    C: Hash,
    A: Hash,
    B: Hash,
    D: Hash + ?Sized
[src]

impl<Ret, A, B, C, D, E, F> Hash for unsafe fn(A, B, C, D, E, F) -> Ret[src]

impl<A, B, C, D, E, F> Hash for (A, B, C, D, E, F) where
    C: Hash,
    A: Hash,
    E: Hash,
    F: Hash + ?Sized,
    B: Hash,
    D: Hash
[src]

impl Hash for isize[src]

impl<T> Hash for *const T where
    T: ?Sized
[src]

impl<A, B, C, D, E, F, G, H, I> Hash for (A, B, C, D, E, F, G, H, I) where
    C: Hash,
    A: Hash,
    E: Hash,
    F: Hash,
    I: Hash + ?Sized,
    B: Hash,
    H: Hash,
    D: Hash,
    G: Hash
[src]

impl<Ret, A> Hash for unsafe extern "C" fn(A, ...) -> Ret[src]

impl<Ret> Hash for extern "C" fn() -> Ret[src]

impl<P> Hash for Pin<P> where
    P: Deref,
    <P as Deref>::Target: Hash
[src]

impl<Ret, A, B, C, D, E, F, G> Hash for unsafe extern "C" fn(A, B, C, D, E, F, G, ...) -> Ret[src]

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, ...) -> Ret[src]

impl<Ret, A, B, C, D> Hash for unsafe fn(A, B, C, D) -> Ret[src]

impl<'a> Hash for Location<'a>[src]

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) -> Ret[src]

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) -> Ret[src]

impl<Ret, A, B, C, D, E, F, G> Hash for extern "C" fn(A, B, C, D, E, F, G, ...) -> Ret[src]

impl Hash for ![src]

impl<Ret, A> Hash for unsafe extern "C" fn(A) -> Ret[src]

impl<Ret, A, B, C> Hash for unsafe fn(A, B, C) -> Ret[src]

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) -> Ret[src]

impl<Ret, A, B> Hash for fn(A, B) -> Ret[src]

impl<Ret, A, B, C, D, E> Hash for extern "C" fn(A, B, C, D, E, ...) -> Ret[src]

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
    C: Hash,
    A: Hash,
    E: Hash,
    K: Hash + ?Sized,
    F: Hash,
    I: Hash,
    B: Hash,
    H: Hash,
    D: Hash,
    G: Hash,
    J: Hash
[src]

impl<Ret, A, B, C, D, E, F> Hash for fn(A, B, C, D, E, F) -> Ret[src]

impl Hash for i32[src]

impl<Ret, A, B, C, D> Hash for extern "C" fn(A, B, C, D) -> Ret[src]

impl<Ret, A> Hash for unsafe fn(A) -> Ret[src]

impl<Ret, A, B> Hash for unsafe extern "C" fn(A, B, ...) -> Ret[src]

impl<Ret, A, B, C, D, E> Hash for unsafe fn(A, B, C, D, E) -> Ret[src]

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) -> Ret[src]

impl<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, ...) -> Ret[src]

impl Hash for i128[src]

impl<A> Hash for (A,) where
    A: Hash + ?Sized
[src]

impl<Ret, A, B, C, D, E> Hash for extern "C" fn(A, B, C, D, E) -> Ret[src]

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, ...) -> Ret[src]

impl Hash for i8[src]

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, ...) -> Ret[src]

impl Hash for char[src]

impl<Ret, A, B, C, D> Hash for unsafe extern "C" fn(A, B, C, D) -> Ret[src]

impl<Ret, A, B, C, D, E, F, G, H> Hash for unsafe extern "C" fn(A, B, C, D, E, F, G, H, ...) -> Ret[src]

impl<Ret, A> Hash for fn(A) -> Ret[src]

impl<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) -> Ret[src]

impl<Ret, A, B> Hash for unsafe extern "C" fn(A, B) -> Ret[src]

impl<A, B, C, D, E> Hash for (A, B, C, D, E) where
    C: Hash,
    A: Hash,
    E: Hash + ?Sized,
    B: Hash,
    D: Hash
[src]

impl<Ret, A, B> Hash for unsafe fn(A, B) -> Ret[src]

impl Hash for Duration[src]

impl<T> Hash for Option<T> where
    T: Hash
[src]

impl Hash for NoneError[src]

impl<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) -> Ret[src]

impl Hash for u64[src]

impl<Ret> Hash for unsafe fn() -> Ret[src]

impl<Ret, A, B, C, D, E> Hash for fn(A, B, C, D, E) -> Ret[src]

impl Hash for u128[src]

impl<Ret, A, B, C> Hash for unsafe extern "C" fn(A, B, C) -> Ret[src]

impl<Ret, A, B, C> Hash for unsafe extern "C" fn(A, B, C, ...) -> Ret[src]

impl<Ret> Hash for fn() -> Ret[src]

impl<'_, T> Hash for &'_ T where
    T: Hash + ?Sized
[src]

impl<Ret, A, B, C, D, E, F, G, H, I> Hash for extern "C" fn(A, B, C, D, E, F, G, H, I) -> Ret[src]

impl<A, B, C, D, E, F, G, H, I, J> Hash for (A, B, C, D, E, F, G, H, I, J) where
    C: Hash,
    A: Hash,
    E: Hash,
    F: Hash,
    I: Hash,
    B: Hash,
    H: Hash,
    D: Hash,
    G: Hash,
    J: Hash + ?Sized
[src]

impl<Ret, A, B, C, D, E, F, G> Hash for extern "C" fn(A, B, C, D, E, F, G) -> Ret[src]

impl<Ret, A, B, C, D, E> Hash for unsafe extern "C" fn(A, B, C, D, E, ...) -> Ret[src]

impl<Ret, A, B, C, D, E, F, G, H> Hash for extern "C" fn(A, B, C, D, E, F, G, H, ...) -> Ret[src]

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) -> Ret[src]

impl<Ret, A, B, C, D, E, F, G, H> Hash for extern "C" fn(A, B, C, D, E, F, G, H) -> Ret[src]

impl<Ret, A, B, C, D, E, F, G, H> Hash for unsafe extern "C" fn(A, B, C, D, E, F, G, H) -> Ret[src]

impl<A, B, C, D, E, F, G, H> Hash for (A, B, C, D, E, F, G, H) where
    C: Hash,
    A: Hash,
    E: Hash,
    F: Hash,
    B: Hash,
    H: Hash + ?Sized,
    D: Hash,
    G: Hash
[src]

impl<Ret> Hash for unsafe extern "C" fn() -> Ret[src]

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) -> Ret[src]

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, ...) -> Ret[src]

impl Hash for i64[src]

impl<Ret, A, B, C, D> Hash for extern "C" fn(A, B, C, D, ...) -> Ret[src]

impl<Ret, A, B, C, D, E, F, G, H, I> Hash for extern "C" fn(A, B, C, D, E, F, G, H, I, ...) -> Ret[src]

impl Hash for i16[src]

impl<Ret, A, B, C, D, E, F, G> Hash for unsafe extern "C" fn(A, B, C, D, E, F, G) -> Ret[src]

impl<'_, T> Hash for &'_ mut T where
    T: Hash + ?Sized
[src]

impl<Ret, A> Hash for extern "C" fn(A, ...) -> Ret[src]

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) -> Ret[src]

impl<Ret, A, B, C, D, E, F, G, H, I, J> Hash for fn(A, B, C, D, E, F, G, H, I, J) -> Ret[src]

impl Hash for u16[src]

impl<T, const N: usize> Hash for [T; N] where
    T: Hash
[src]

impl<Ret, A, B, C, D, E, F> Hash for extern "C" fn(A, B, C, D, E, F) -> Ret[src]

impl<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) -> Ret[src]

impl Hash for String[src]

impl<T> Hash for LinkedList<T> where
    T: Hash
[src]

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Implementors

impl Hash for sp_std::cmp::Ordering[src]

impl Hash for Infallible[src]

impl Hash for sp_std::sync::atomic::Ordering[src]

impl Hash for TypeId[src]

impl Hash for Error[src]

impl Hash for PhantomPinned[src]

impl Hash for NonZeroI8[src]

impl Hash for NonZeroI16[src]

impl Hash for NonZeroI32[src]

impl Hash for NonZeroI64[src]

impl Hash for NonZeroI128[src]

impl Hash for NonZeroIsize[src]

impl Hash for NonZeroU8[src]

impl Hash for NonZeroU16[src]

impl Hash for NonZeroU32[src]

impl Hash for NonZeroU64[src]

impl Hash for NonZeroU128[src]

impl Hash for NonZeroUsize[src]

impl Hash for RangeFull[src]

impl<'_, B> Hash for Cow<'_, B> where
    B: Hash + ToOwned + ?Sized
[src]

impl<A> Hash for VecDeque<A> where
    A: Hash
[src]

impl<Idx> Hash for Range<Idx> where
    Idx: Hash
[src]

impl<Idx> Hash for RangeFrom<Idx> where
    Idx: Hash
[src]

impl<Idx> Hash for RangeInclusive<Idx> where
    Idx: Hash
[src]

impl<Idx> Hash for RangeTo<Idx> where
    Idx: Hash
[src]

impl<Idx> Hash for RangeToInclusive<Idx> where
    Idx: Hash
[src]

impl<K, V> Hash for BTreeMap<K, V> where
    K: Hash,
    V: Hash
[src]

impl<T> Hash for Bound<T> where
    T: Hash
[src]

impl<T> Hash for BTreeSet<T> where
    T: Hash
[src]

impl<T> Hash for PhantomData<T> where
    T: ?Sized
[src]

impl<T> Hash for Discriminant<T>[src]

impl<T> Hash for ManuallyDrop<T> where
    T: Hash + ?Sized
[src]

impl<T> Hash for Wrapping<T> where
    T: Hash
[src]

impl<T> Hash for Reverse<T> where
    T: Hash
[src]

impl<T> Hash for NonNull<T> where
    T: ?Sized
[src]

impl<T> Hash for Rc<T> where
    T: Hash + ?Sized
[src]

impl<T> Hash for Arc<T> where
    T: Hash + ?Sized
[src]

impl<T, A> Hash for Box<T, A> where
    T: Hash + ?Sized,
    A: Allocator
[src]

impl<T, A> Hash for Vec<T, A> where
    T: Hash,
    A: Allocator
[src]

impl<T, E> Hash for Result<T, E> where
    T: Hash,
    E: Hash
[src]

impl<Y, R> Hash for GeneratorState<Y, R> where
    R: Hash,
    Y: Hash
[src]

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