Struct ethprim::Digest

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pub struct Digest(pub [u8; 32]);

Expand description

A 32-byte digest.

Tuple Fields

0: [u8; 32]

Implementations

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impl Digest

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pub fn from_slice(slice: &[u8]) -> Digest

Creates a digest from a slice.

Panics

This method panics if the length of the slice is not 32 bytes.

Examples

Basic usage:

let buffer = (0..255).collect::<Vec<_>>();
assert_eq!(
    Digest::from_slice(&buffer[0..32]),
    Digest([
        0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
        0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
        0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
        0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
    ]),
);

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pub fn from_ref(array: &[u8; 32]) -> &Digest

Creates a reference to a digest from a reference to a 32-byte array.

Examples

Basic usage:

let arrays = [[0; 32], [1; 32]];
for digest in arrays.iter().map(Digest::from_ref) {
    println!("{digest}");
}

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pub fn from_mut(array: &mut [u8; 32]) -> &mut Digest

Creates a mutable reference to a digest from a mutable reference to a 32-byte array.

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pub fn of(data: impl AsRef<[u8]>) -> Digest

Creates a digest by hashing some input.

Examples

Basic usage:

assert_eq!(
    Digest::of("Hello Ethereum!"),
    Digest([
        0x67, 0xe0, 0x83, 0xfb, 0x08, 0x73, 0x8b, 0x8d,
        0x79, 0x84, 0xe3, 0x49, 0x68, 0x7f, 0xec, 0x5b,
        0xf0, 0x32, 0x24, 0xc2, 0xda, 0xd4, 0x90, 0x60,
        0x20, 0xdf, 0xab, 0x9a, 0x0e, 0x4c, 0xee, 0xac,
    ]),
);

Methods from Deref<Target = [u8; 32]>

1.57.0 · source

pub fn as_slice(&self) -> &[T] ⓘ

Returns a slice containing the entire array. Equivalent to &s[..].

1.57.0 · source

pub fn as_mut_slice(&mut self) -> &mut [T] ⓘ

Returns a mutable slice containing the entire array. Equivalent to &mut s[..].

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pub fn each_ref(&self) -> [&T; N]

🔬This is a nightly-only experimental API. (array_methods)

Borrows each element and returns an array of references with the same size as self.

Example

#![feature(array_methods)]

let floats = [3.1, 2.7, -1.0];
let float_refs: [&f64; 3] = floats.each_ref();
assert_eq!(float_refs, [&3.1, &2.7, &-1.0]);

This method is particularly useful if combined with other methods, like map. This way, you can avoid moving the original array if its elements are not Copy.

#![feature(array_methods)]

let strings = ["Ferris".to_string(), "♥".to_string(), "Rust".to_string()];
let is_ascii = strings.each_ref().map(|s| s.is_ascii());
assert_eq!(is_ascii, [true, false, true]);

// We can still access the original array: it has not been moved.
assert_eq!(strings.len(), 3);

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pub fn each_mut(&mut self) -> [&mut T; N]

🔬This is a nightly-only experimental API. (array_methods)

Borrows each element mutably and returns an array of mutable references with the same size as self.

Example

#![feature(array_methods)]

let mut floats = [3.1, 2.7, -1.0];
let float_refs: [&mut f64; 3] = floats.each_mut();
*float_refs[0] = 0.0;
assert_eq!(float_refs, [&mut 0.0, &mut 2.7, &mut -1.0]);
assert_eq!(floats, [0.0, 2.7, -1.0]);

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pub fn split_array_ref<const M: usize>(&self) -> (&[T; M], &[T])

🔬This is a nightly-only experimental API. (split_array)

Divides one array reference into two at an index.

The first will contain all indices from [0, M) (excluding the index M itself) and the second will contain all indices from [M, N) (excluding the index N itself).

Panics

Panics if M > N.

Examples

#![feature(split_array)]

let v = [1, 2, 3, 4, 5, 6];

{
   let (left, right) = v.split_array_ref::<0>();
   assert_eq!(left, &[]);
   assert_eq!(right, &[1, 2, 3, 4, 5, 6]);
}

{
    let (left, right) = v.split_array_ref::<2>();
    assert_eq!(left, &[1, 2]);
    assert_eq!(right, &[3, 4, 5, 6]);
}

{
    let (left, right) = v.split_array_ref::<6>();
    assert_eq!(left, &[1, 2, 3, 4, 5, 6]);
    assert_eq!(right, &[]);
}

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pub fn split_array_mut<const M: usize>(&mut self) -> (&mut [T; M], &mut [T])

🔬This is a nightly-only experimental API. (split_array)

Divides one mutable array reference into two at an index.

The first will contain all indices from [0, M) (excluding the index M itself) and the second will contain all indices from [M, N) (excluding the index N itself).

Panics

Panics if M > N.

Examples

#![feature(split_array)]

let mut v = [1, 0, 3, 0, 5, 6];
let (left, right) = v.split_array_mut::<2>();
assert_eq!(left, &mut [1, 0][..]);
assert_eq!(right, &mut [3, 0, 5, 6]);
left[1] = 2;
right[1] = 4;
assert_eq!(v, [1, 2, 3, 4, 5, 6]);

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pub fn rsplit_array_ref<const M: usize>(&self) -> (&[T], &[T; M])

🔬This is a nightly-only experimental API. (split_array)

Divides one array reference into two at an index from the end.

The first will contain all indices from [0, N - M) (excluding the index N - M itself) and the second will contain all indices from [N - M, N) (excluding the index N itself).

Panics

Panics if M > N.

Examples

#![feature(split_array)]

let v = [1, 2, 3, 4, 5, 6];

{
   let (left, right) = v.rsplit_array_ref::<0>();
   assert_eq!(left, &[1, 2, 3, 4, 5, 6]);
   assert_eq!(right, &[]);
}

{
    let (left, right) = v.rsplit_array_ref::<2>();
    assert_eq!(left, &[1, 2, 3, 4]);
    assert_eq!(right, &[5, 6]);
}

{
    let (left, right) = v.rsplit_array_ref::<6>();
    assert_eq!(left, &[]);
    assert_eq!(right, &[1, 2, 3, 4, 5, 6]);
}

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pub fn rsplit_array_mut<const M: usize>(&mut self) -> (&mut [T], &mut [T; M])

🔬This is a nightly-only experimental API. (split_array)

Divides one mutable array reference into two at an index from the end.

The first will contain all indices from [0, N - M) (excluding the index N - M itself) and the second will contain all indices from [N - M, N) (excluding the index N itself).

Panics

Panics if M > N.

Examples

#![feature(split_array)]

let mut v = [1, 0, 3, 0, 5, 6];
let (left, right) = v.rsplit_array_mut::<4>();
assert_eq!(left, &mut [1, 0]);
assert_eq!(right, &mut [3, 0, 5, 6][..]);
left[1] = 2;
right[1] = 4;
assert_eq!(v, [1, 2, 3, 4, 5, 6]);