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
use disjoint_impls::disjoint_impls;
pub trait Dispatch {
type Group;
}
pub enum GroupA {}
impl Dispatch for String {
type Group = GroupA;
}
impl<T> Dispatch for Vec<T> {
type Group = GroupA;
}
pub enum GroupB {}
impl Dispatch for i32 {
type Group = GroupB;
}
impl Dispatch for u32 {
type Group = GroupB;
}
pub trait Kara {}
impl Dispatch for dyn Kara {
type Group = GroupA;
}
disjoint_impls! {
pub trait Kita<T> {
const NAME: &'static str;
}
impl<T: Dispatch<Group = GroupA>> Kita<T> for dyn Kara + Sync {
const NAME: &'static str = "Blanket A";
}
impl<T: Dispatch<Group = GroupB>> Kita<T> for dyn Kara + Sync {
const NAME: &'static str = "Blanket B";
}
impl<T: Dispatch<Group = GroupA>> Kita<T> for dyn Kara {
const NAME: &'static str = "Blanket C";
}
impl<T: Dispatch<Group = GroupB>> Kita<T> for dyn Kara {
const NAME: &'static str = "Blanket D";
}
}
/*
pub trait Kita<T> {
const NAME: &'static str;
}
const _: () = {
pub trait Kita0<_TŠČ1: ?core::marker::Sized, _TŠČ0>: Kita<_TŠČ0> {
const NAME_šč: &'static str;
}
impl<T: Dispatch<Group = GroupA>> Kita0<GroupA, T> for dyn Kara + Sync {
const NAME_šč: &'static str = "Blanket A";
}
impl<T: Dispatch<Group = GroupB>> Kita0<GroupB, T> for dyn Kara + Sync {
const NAME_šč: &'static str = "Blanket B";
}
pub trait Kita1<_TŠČ1: ?core::marker::Sized, _TŠČ0>: Kita<_TŠČ0> {
const NAME_šč: &'static str;
}
impl<T: Dispatch<Group = GroupA>> Kita1<GroupA, T> for dyn Kara {
const NAME_šč: &'static str = "Blanket C";
}
impl<T: Dispatch<Group = GroupB>> Kita1<GroupB, T> for dyn Kara {
const NAME_šč: &'static str = "Blanket D";
}
impl<_TŠČ0> Kita<_TŠČ0> for dyn Kara + Sync
where
_TŠČ0: Dispatch,
Self: for<'_dšč> Kita0<<_TŠČ0 as Dispatch>::Group, _TŠČ0>,
{
const NAME: &'static str = <Self as Kita0<
<_TŠČ0 as Dispatch>::Group,
_TŠČ0,
>>::NAME_šč;
}
impl<_TŠČ0> Kita<_TŠČ0> for dyn Kara
where
_TŠČ0: Dispatch,
Self: for<'_dšč> Kita1<<_TŠČ0 as Dispatch>::Group, _TŠČ0>,
{
const NAME: &'static str = <Self as Kita1<
<_TŠČ0 as Dispatch>::Group,
_TŠČ0,
>>::NAME_šč;
}
};
*/
fn main() {
assert_eq!(<dyn Kara + Sync as Kita::<String>>::NAME, "Blanket A");
assert_eq!(<dyn Sync + Kara as Kita::<u32>>::NAME, "Blanket B");
assert_eq!(<dyn Kara as Kita::<String>>::NAME, "Blanket C");
assert_eq!(<dyn Kara as Kita::<u32>>::NAME, "Blanket D");
}