generic-bytes-derive 0.2.3

A macro for derivation of SizedBytes, a trait for conversion to and from an array of bytes with a type-level size
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53

// Copyright (c) Facebook, Inc. and its affiliates.
//
// This source code is licensed under the MIT license found in the
// LICENSE file in the root directory of this source tree.

use generic_array::{
    arr,
    typenum::{U0, U32},
    GenericArray,
};
use generic_bytes::SizedBytes;
use generic_bytes_derive::SizedBytes;

#[derive(SizedBytes)]
struct Foo<T: Baz> {
    f1: T::Quux,
    f2: GenericArray<u8, U32>,
}

struct Bar();

impl generic_bytes::SizedBytes for Bar {
    type Len = U0;

    fn to_arr(&self) -> GenericArray<u8, U0> {
        arr![u8;]
    }

    fn from_arr(
        _bytes: &GenericArray<u8, U0>,
    ) -> Result<Bar, generic_bytes::TryFromSizedBytesError> {
        Ok(Bar())
    }
}

trait Baz {
    type Quux: SizedBytes;
}

struct Corge {}
impl Baz for Corge {
    type Quux = Bar;
}

#[test]
fn test_foo() {
    let d2 = [2u8; 32];

    let g1 = Bar();
    let g2 = GenericArray::from_slice(&d2);

    let _foo: Foo<Corge> = Foo { f1: g1, f2: *g2 };
}