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

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,
}

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

fn hash<H>(&self, state: &mut H) where
    H: Hasher

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

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

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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Implementors

impl Hash for ![src]

impl Hash for ()[src]

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

impl Hash for Infallible[src]

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

impl Hash for TypeId[src]

impl Hash for Error[src]

impl Hash for PhantomPinned[src]

impl Hash for NonZeroI128[src]

impl Hash for NonZeroI16[src]

impl Hash for NonZeroI32[src]

impl Hash for NonZeroI64[src]

impl Hash for NonZeroI8[src]

impl Hash for NonZeroIsize[src]

impl Hash for NonZeroU128[src]

impl Hash for NonZeroU16[src]

impl Hash for NonZeroU32[src]

impl Hash for NonZeroU64[src]

impl Hash for NonZeroU8[src]

impl Hash for NonZeroUsize[src]

impl Hash for RangeFull[src]

impl Hash for NoneError[src]

impl Hash for Duration[src]

impl Hash for bool[src]

impl Hash for char[src]

impl Hash for i8[src]

impl Hash for i16[src]

impl Hash for i32[src]

impl Hash for i64[src]

impl Hash for i128[src]

impl Hash for isize[src]

impl Hash for str[src]

impl Hash for u8[src]

impl Hash for u16[src]

impl Hash for u32[src]

impl Hash for u64[src]

impl Hash for u128[src]

impl Hash for usize[src]

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

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

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

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

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

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

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

impl<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
[src]

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
[src]

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
[src]

impl<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
[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
    A: Hash,
    B: Hash,
    C: Hash,
    D: Hash,
    E: Hash,
    F: Hash,
    G: Hash,
    H: Hash,
    I: Hash,
    J: Hash + ?Sized
[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
    A: Hash,
    B: Hash,
    C: Hash,
    D: Hash,
    E: Hash,
    F: Hash,
    G: Hash,
    H: Hash,
    I: Hash,
    J: Hash,
    K: Hash + ?Sized
[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
    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
[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<P> Hash for Pin<P> where
    P: Deref,
    <P as Deref>::Target: Hash
[src]

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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