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
use core::slice;
pub trait Internal<V>: Sized {
type Array;
#[doc(hidden)]
fn slice(array: &Self::Array) -> &[V];
#[doc(hidden)]
fn slice_mut(array: &mut Self::Array) -> &mut [V];
#[doc(hidden)]
fn from_usize(value: usize) -> Self;
#[doc(hidden)]
fn to_usize(self) -> usize;
#[doc(hidden)]
fn from_function<F: FnMut(Self) -> V>(f: F) -> Self::Array;
}
impl<T> Internal<T> for bool {
type Array = [T; 2];
#[inline]
fn slice(array: &[T; 2]) -> &[T] {
array
}
#[inline]
fn slice_mut(array: &mut [T; 2]) -> &mut [T] {
array
}
#[inline]
fn from_usize(value: usize) -> Self {
match value {
0 => false,
1 => true,
_ => unreachable!(),
}
}
#[inline]
fn to_usize(self) -> usize {
self as usize
}
#[inline]
fn from_function<F: FnMut(Self) -> T>(mut f: F) -> [T; 2] {
[f(false), f(true)]
}
}
impl<T> Internal<T> for u8 {
type Array = [T; 256];
#[inline]
fn slice(array: &[T; 256]) -> &[T] {
array
}
#[inline]
fn slice_mut(array: &mut [T; 256]) -> &mut [T] {
array
}
#[inline]
fn from_usize(value: usize) -> Self {
value as u8
}
#[inline]
fn to_usize(self) -> usize {
self as usize
}
#[inline]
fn from_function<F: FnMut(Self) -> T>(mut f: F) -> [T; 256] {
array![|i| f(i as u8); 256]
}
}
#[repr(C)]
#[derive(Copy, Clone)]
pub struct OptionInternal<T, U> {
none: T,
some: U,
}
#[deprecated(
since = "0.2.30", note = "the implementation is unsafe, and will be removed in enum-map 0.3.0"
)]
impl<T, U: Internal<T>> Internal<T> for Option<U> {
type Array = OptionInternal<T, U::Array>;
fn slice(array: &Self::Array) -> &[T] {
unsafe {
slice::from_raw_parts(
array as *const _ as *const T,
1 + U::slice(&array.some).len(),
)
}
}
fn slice_mut(array: &mut Self::Array) -> &mut [T] {
unsafe {
slice::from_raw_parts_mut(array as *mut _ as *mut T, 1 + U::slice(&array.some).len())
}
}
fn from_usize(value: usize) -> Self {
match value {
0 => None,
v => Some(U::from_usize(v - 1)),
}
}
fn to_usize(self) -> usize {
match self {
None => 0,
Some(x) => x.to_usize() + 1,
}
}
fn from_function<F: FnMut(Self) -> T>(mut f: F) -> Self::Array {
OptionInternal {
none: f(None),
some: U::from_function(|x| f(Some(x))),
}
}
}