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
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213

use core::marker::PhantomData;
use std::{rc::Rc, sync::Arc};

use bitvec::{order::Msb0, vec::BitVec};

use crate::{BitPack, BitWriter, BitWriterExt, ResultExt, StringError};

pub trait BitPackAs<T: ?Sized> {
    fn pack_as<W>(source: &T, writer: W) -> Result<(), W::Error>
    where
        W: BitWriter;
}

#[inline]
pub fn pack_as<T, As>(value: T) -> Result<BitVec<u8, Msb0>, StringError>
where
    As: BitPackAs<T> + ?Sized,
{
    let mut writer = BitVec::new();
    writer.pack_as::<_, As>(value)?;
    Ok(writer)
}

pub struct BitPackAsWrap<'a, T, As>
where
    As: BitPackAs<T> + ?Sized,
    T: ?Sized,
{
    value: &'a T,
    _phantom: PhantomData<As>,
}

impl<'a, T, As> BitPackAsWrap<'a, T, As>
where
    T: ?Sized,
    As: BitPackAs<T> + ?Sized,
{
    #[inline]
    pub const fn new(value: &'a T) -> Self {
        Self {
            value,
            _phantom: PhantomData,
        }
    }
}

impl<'a, T, As> BitPack for BitPackAsWrap<'a, T, As>
where
    T: ?Sized,
    As: ?Sized,
    As: BitPackAs<T>,
{
    #[inline]
    fn pack<W>(&self, writer: W) -> Result<(), W::Error>
    where
        W: BitWriter,
    {
        As::pack_as(self.value, writer)
    }
}

impl<'a, T, As> BitPackAs<&'a T> for &'a As
where
    As: BitPackAs<T> + ?Sized,
    T: ?Sized,
{
    #[inline]
    fn pack_as<W>(source: &&T, writer: W) -> Result<(), W::Error>
    where
        W: BitWriter,
    {
        BitPackAsWrap::<T, As>::new(source).pack(writer)
    }
}

impl<'a, T, As> BitPackAs<&'a mut T> for &'a mut As
where
    As: BitPackAs<T> + ?Sized,
    T: ?Sized,
{
    #[inline]
    fn pack_as<W>(source: &&mut T, writer: W) -> Result<(), W::Error>
    where
        W: BitWriter,
    {
        BitPackAsWrap::<T, As>::new(source).pack(writer)
    }
}

impl<T, As> BitPackAs<[T]> for [As]
where
    As: BitPackAs<T>,
{
    #[inline]
    fn pack_as<W>(source: &[T], mut writer: W) -> Result<(), W::Error>
    where
        W: BitWriter,
    {
        for (i, v) in source.iter().enumerate() {
            writer
                .pack_as::<&T, &As>(v)
                .with_context(|| format!("[{i}]"))?;
        }
        Ok(())
    }
}

impl<T, As, const N: usize> BitPackAs<[T; N]> for [As; N]
where
    As: BitPackAs<T>,
{
    #[inline]
    fn pack_as<W>(source: &[T; N], mut writer: W) -> Result<(), W::Error>
    where
        W: BitWriter,
    {
        writer.pack_as::<&[T], &[As]>(source)?;
        Ok(())
    }
}

macro_rules! impl_bit_pack_as_for_tuple {
    ($($n:tt:$t:ident as $a:ident),+) => {
        impl<$($t, $a),+> BitPackAs<($($t,)+)> for ($($a,)+)
        where $(
            $a: BitPackAs<$t>,
        )+
        {
            #[inline]
            fn pack_as<W>(source: &($($t,)+), mut writer: W) -> Result<(), W::Error>
            where
                W: BitWriter,
            {
                writer$(
                    .pack_as::<&$t, &$a>(&source.$n)?)+;
                Ok(())
            }
        }
    };
}
impl_bit_pack_as_for_tuple!(0:T0 as As0);
impl_bit_pack_as_for_tuple!(0:T0 as As0,1:T1 as As1);
impl_bit_pack_as_for_tuple!(0:T0 as As0,1:T1 as As1,2:T2 as As2);
impl_bit_pack_as_for_tuple!(0:T0 as As0,1:T1 as As1,2:T2 as As2,3:T3 as As3);
impl_bit_pack_as_for_tuple!(0:T0 as As0,1:T1 as As1,2:T2 as As2,3:T3 as As3,4:T4 as As4);
impl_bit_pack_as_for_tuple!(0:T0 as As0,1:T1 as As1,2:T2 as As2,3:T3 as As3,4:T4 as As4,5:T5 as As5);
impl_bit_pack_as_for_tuple!(0:T0 as As0,1:T1 as As1,2:T2 as As2,3:T3 as As3,4:T4 as As4,5:T5 as As5,6:T6 as As6);
impl_bit_pack_as_for_tuple!(0:T0 as As0,1:T1 as As1,2:T2 as As2,3:T3 as As3,4:T4 as As4,5:T5 as As5,6:T6 as As6,7:T7 as As7);
impl_bit_pack_as_for_tuple!(0:T0 as As0,1:T1 as As1,2:T2 as As2,3:T3 as As3,4:T4 as As4,5:T5 as As5,6:T6 as As6,7:T7 as As7,8:T8 as As8);
impl_bit_pack_as_for_tuple!(0:T0 as As0,1:T1 as As1,2:T2 as As2,3:T3 as As3,4:T4 as As4,5:T5 as As5,6:T6 as As6,7:T7 as As7,8:T8 as As8,9:T9 as As9);

impl<T, As> BitPackAs<Box<T>> for Box<As>
where
    As: BitPackAs<T> + ?Sized,
{
    fn pack_as<W>(source: &Box<T>, writer: W) -> Result<(), W::Error>
    where
        W: BitWriter,
    {
        BitPackAsWrap::<T, As>::new(source).pack(writer)
    }
}

impl<T, As> BitPackAs<Rc<T>> for Rc<As>
where
    As: BitPackAs<T> + ?Sized,
{
    fn pack_as<W>(source: &Rc<T>, writer: W) -> Result<(), W::Error>
    where
        W: BitWriter,
    {
        BitPackAsWrap::<T, As>::new(source).pack(writer)
    }
}

impl<T, As> BitPackAs<Arc<T>> for Arc<As>
where
    As: BitPackAs<T> + ?Sized,
{
    fn pack_as<W>(source: &Arc<T>, writer: W) -> Result<(), W::Error>
    where
        W: BitWriter,
    {
        BitPackAsWrap::<T, As>::new(source).pack(writer)
    }
}

impl<T, As> BitPackAs<Option<T>> for Option<As>
where
    As: BitPackAs<T>,
{
    #[inline]
    fn pack_as<W>(source: &Option<T>, writer: W) -> Result<(), W::Error>
    where
        W: BitWriter,
    {
        source
            .as_ref()
            .map(BitPackAsWrap::<T, As>::new)
            .pack(writer)
    }
}

pub trait BitPackWrapAsExt {
    #[inline]
    fn wrap_as<As>(&self) -> BitPackAsWrap<'_, Self, As>
    where
        As: BitPackAs<Self> + ?Sized,
    {
        BitPackAsWrap::new(self)
    }
}
impl<T> BitPackWrapAsExt for T {}