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
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
|
use std::convert::TryInto;
use iterative_conversion_impl::PaddedShiftLeft;
pub(super) use iterative_conversion::IterativeBaseConversion;
pub(super) use iterative_conversion_impl::{SixteenBytes, ArbitraryBytes};
use self::iterative_conversion::PrecomputedMaxPowers;
mod iterative_conversion;
mod iterative_conversion_impl;
/// Converts an input to a different base (which fits in usize). Returns the digits starting at the most significant one.
pub(super) trait BaseConversion {
type Output : ExactSizeIterator<Item=usize>;
fn convert_to_base(self, base : usize) -> Self::Output;
}
#[allow(clippy::trait_duplication_in_bounds)] //False positive in clippy. usize != u32.
impl<T, const N : usize, const M : usize> BaseConversion for T
where T : ToArbitraryBytes<Output = ArbitraryBytes<N>>,
for<'a> T::Output: From<&'a usize> + From<&'a u32> + PaddedShiftLeft<Output = ArbitraryBytes<M>> + PrecomputedMaxPowers<usize>,
{
type Output = IterativeBaseConversion<ArbitraryBytes<N>, usize>;
fn convert_to_base(self, base : usize) -> Self::Output {
IterativeBaseConversion::new(self.to_arbitrary_bytes(), base)
}
}
impl BaseConversion for [u8;16]{
type Output = IterativeBaseConversion<SixteenBytes,usize>;
fn convert_to_base(self, base : usize) -> IterativeBaseConversion<SixteenBytes,usize> {
IterativeBaseConversion::new(SixteenBytes::new(u128::from_be_bytes(self)), base)
}
}
// Rust 1.52 only has a very limited support for const generics. This means, we'll have to live with this not-too-constrained solution...
pub(super) trait ToArbitraryBytes {
type Output;
fn to_arbitrary_bytes(self) -> Self::Output;
}
//this could of course be done in a generic manner, but it's ugly without array_mut, which we don't have in Rust 1.52.
//Soo, pedestrian's approach :D
impl ToArbitraryBytes for [u8;20] {
type Output = ArbitraryBytes<5>;
fn to_arbitrary_bytes(self) -> ArbitraryBytes<5> {
ArbitraryBytes::new([
u32::from_be_bytes(self[0..4].try_into().unwrap()),
u32::from_be_bytes(self[4..8].try_into().unwrap()),
u32::from_be_bytes(self[8..12].try_into().unwrap()),
u32::from_be_bytes(self[12..16].try_into().unwrap()),
u32::from_be_bytes(self[16..20].try_into().unwrap()),
])
}
}
impl ToArbitraryBytes for [u8;32] {
type Output = ArbitraryBytes<8>;
fn to_arbitrary_bytes(self) -> ArbitraryBytes<8> {
ArbitraryBytes::new([
u32::from_be_bytes(self[0..4].try_into().unwrap()),
u32::from_be_bytes(self[4..8].try_into().unwrap()),
u32::from_be_bytes(self[8..12].try_into().unwrap()),
u32::from_be_bytes(self[12..16].try_into().unwrap()),
u32::from_be_bytes(self[16..20].try_into().unwrap()),
u32::from_be_bytes(self[20..24].try_into().unwrap()),
u32::from_be_bytes(self[24..28].try_into().unwrap()),
u32::from_be_bytes(self[28..32].try_into().unwrap()),
])
}
}
|
