1.0.0[][src]Trait scale_info::prelude::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 SocketAddr[src]

impl Hash for PathBuf[src]

impl Hash for OsString[src]

impl Hash for Ipv6Addr[src]

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

impl Hash for ErrorKind[src]

impl Hash for OsStr[src]

impl Hash for ThreadId[src]

impl Hash for UCred[src]

impl Hash for Ipv6MulticastScope[src]

impl Hash for Path[src]

impl Hash for IpAddr[src]

impl Hash for SocketAddrV4[src]

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

impl Hash for SystemTime[src]

impl Hash for Ipv4Addr[src]

impl Hash for CString[src]

impl Hash for Instant[src]

impl Hash for CStr[src]

impl Hash for FileType[src]

impl Hash for SocketAddrV6[src]

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

impl Hash for char[src]

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

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

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

impl<A, B, C, D, E, F, G, H> Hash for (A, B, C, D, E, F, G, H) where
    C: Hash,
    D: Hash,
    F: Hash,
    A: Hash,
    B: Hash,
    E: Hash,
    G: Hash,
    H: Hash + ?Sized
[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 extern "C" fn(A, B, C, D, E, F, G, H, I, ...) -> 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,
    D: Hash,
    F: Hash,
    A: Hash,
    B: Hash,
    E: Hash,
    G: Hash + ?Sized
[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<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<A, B, C, D> Hash for (A, B, C, D) where
    C: Hash,
    D: Hash + ?Sized,
    A: Hash,
    B: Hash
[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 i16[src]

impl<Ret, A, B> Hash for extern "C" fn(A, B, ...) -> 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<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<T> Hash for *mut T where
    T: ?Sized
[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, E, F, G, H, I, J> Hash for (A, B, C, D, E, F, G, H, I, J) where
    C: Hash,
    D: Hash,
    F: Hash,
    I: Hash,
    A: Hash,
    B: Hash,
    E: Hash,
    G: Hash,
    H: Hash,
    J: Hash + ?Sized
[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 Hash for u16[src]

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

impl Hash for RangeFull[src]

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

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

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

impl Hash for i64[src]

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

impl<Ret, A, B, C> Hash for fn(A, B, C) -> 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 Hash for u8[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, 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, 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<A, B, C, D, E, F, G, H, I> Hash for (A, B, C, D, E, F, G, H, I) where
    C: Hash,
    D: Hash,
    F: Hash,
    I: Hash + ?Sized,
    A: Hash,
    B: Hash,
    E: Hash,
    G: Hash,
    H: Hash
[src]

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

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

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

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

impl<Ret, A, B> Hash for extern "C" fn(A, B) -> 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<A> Hash for (A,) where
    A: Hash + ?Sized
[src]

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

impl<'_, T> Hash for &'_ mut T where
    T: Hash + ?Sized
[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> Hash for unsafe fn(A, B) -> Ret[src]

impl<Ret> Hash for extern "C" fn() -> 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, I, J> Hash for unsafe extern "C" fn(A, B, C, D, E, F, G, H, I, J) -> 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 Hash for u32[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> Hash for unsafe extern "C" fn(A, B, C) -> Ret[src]

impl Hash for u64[src]

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

impl Hash for NoneError[src]

impl Hash for ()[src]

impl Hash for isize[src]

impl Hash for u128[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, 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, I> Hash for extern "C" fn(A, B, C, D, E, F, G, H, I) -> Ret[src]

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

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

impl<'_, T> Hash for &'_ T where
    T: Hash + ?Sized
[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 Hash for i32[src]

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

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

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

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

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

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

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

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

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

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

impl Hash for i128[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,
    D: Hash,
    F: Hash,
    I: Hash,
    A: Hash,
    B: Hash,
    E: Hash,
    G: Hash,
    H: Hash,
    J: Hash,
    K: Hash + ?Sized
[src]

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

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

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

impl<Ret, A, B, C, D, E, F> Hash for extern "C" 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,
    D: Hash,
    F: Hash + ?Sized,
    A: Hash,
    B: Hash,
    E: Hash
[src]

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

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

impl<Idx> Hash for RangeToInclusive<Idx> where
    Idx: Hash
[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 Hash for usize[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> Hash for unsafe fn(A, B, C, D) -> 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,
    D: Hash,
    F: Hash,
    I: Hash,
    A: Hash,
    B: Hash,
    E: Hash,
    G: Hash,
    H: Hash,
    J: Hash,
    K: Hash,
    L: Hash + ?Sized
[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<Ret, A, B, C, D, E, F> Hash for unsafe extern "C" fn(A, B, C, D, E, F) -> Ret[src]

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

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

impl Hash for Infallible[src]

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

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

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

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

impl<A> Hash for ArrayString<A> where
    A: Array<Item = u8> + Copy
[src]

impl<A> Hash for ArrayVec<A> where
    A: Array,
    <A as Array>::Item: Hash
[src]

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Implementors

impl Hash for scale_info::prelude::cmp::Ordering[src]

impl Hash for TypeId[src]

impl Hash for Error[src]

impl Hash for PhantomPinned1.33.0[src]

impl Hash for NonZeroI81.34.0[src]

impl Hash for NonZeroI161.34.0[src]

impl Hash for NonZeroI321.34.0[src]

impl Hash for NonZeroI641.34.0[src]

impl Hash for NonZeroI1281.34.0[src]

impl Hash for NonZeroIsize1.34.0[src]

impl Hash for NonZeroU81.28.0[src]

impl Hash for NonZeroU161.28.0[src]

impl Hash for NonZeroU321.28.0[src]

impl Hash for NonZeroU641.28.0[src]

impl Hash for NonZeroU1281.28.0[src]

impl Hash for NonZeroUsize1.28.0[src]

impl Hash for String[src]

impl Hash for MetaType[src]

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

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

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

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

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

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

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

impl<T> Hash for Discriminant<T>1.21.0[src]

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

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

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