const-str 0.3.0

compile-time string operations
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

#![deny(unsafe_code)]

pub const fn num_to_hex_digit(x: u8) -> u8 {
    match x {
        0..=9 => b'0' + x,
        10..=15 => b'a' + (x - 10),
        _ => constfn_panic!("invalid hex number"),
    }
}

// const since 1.52
pub const fn to_lowercase(x: u8) -> u8 {
    match x {
        b'A'..=b'Z' => x + (b'a' - b'A'),
        _ => x,
    }
}

// const since 1.52
pub const fn to_uppercase(x: u8) -> u8 {
    match x {
        b'a'..=b'z' => x - (b'a' - b'A'),
        _ => x,
    }
}

pub const fn num_from_dec_digit(d: u8) -> u8 {
    match d {
        b'0'..=b'9' => d - b'0',
        _ => constfn_panic!("invalid dec digit"),
    }
}