helpers4 0.0.6

General-purpose Rust helpers, one crate, one feature per module (string, array, ...)
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

// This file is part of helpers4.
// Copyright (C) 2025 baxyz
// SPDX-License-Identifier: LGPL-3.0-or-later

use super::decode_to_slice::decode_to_slice;
use super::error::DecodeError;

/// Decodes a hexadecimal string into a fixed-size array, e.g. a 32-byte key from 64 hex digits.
///
/// # Arguments
///
/// - `hex` - The hexadecimal string to decode; must encode exactly `N` bytes.
///
/// # Errors
///
/// Same as [`decode_to_slice`](super::decode_to_slice): the string must have exactly `2 * N`
/// hex digits.
///
/// # Examples
///
/// ```
/// use helpers4::hex::decode_array;
///
/// let key: [u8; 4] = decode_array("deadbeef")?;
/// assert_eq!(key, [0xde, 0xad, 0xbe, 0xef]);
/// assert!(decode_array::<4>("dead").is_err());
/// # Ok::<(), helpers4::hex::DecodeError>(())
/// ```
pub fn decode_array<const N: usize>(hex: &str) -> Result<[u8; N], DecodeError> {
    let mut out = [0u8; N];
    decode_to_slice(hex, &mut out)?;
    Ok(out)
}

#[cfg(test)]
#[path = "decode_array.test.rs"]
mod tests;

#[cfg(test)]
#[path = "decode_array.spec.rs"]
mod spec;