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
/**
The `GetStaticEquivalent` macro derives the [`GetStaticEquivalent_`] trait.
Implementing [`GetStaticEquivalent_`] allows the type to be passed as a
type argument of a type deriving `StableAbi`,
that used the
[`#[sabi(not_stableabi(TypeParameter))]`](derive@crate::StableAbi#sabinot_stableabitypeparameter)
helper attribute.
# Container Attributes
These helper attributes are applied on the type declaration.
<span id = "impl_InterfaceType"></span>
### `#[sabi(impl_InterfaceType(...))]`
Implements the `InterfaceType` trait for a type,
defining the usable/required traits when creating a
`DynTrait<_, ThisType>`/`NonExhaustive<_, _, ThisType>`.
Syntax: `#[sabi(impl_InterfaceType(Trait0, Trait1, ..., TraitN))]`
If a trait is not specified,
it will not be required when constructing DynTrait/NonExhaustive,
and won't be usable afterwards.
<a href = "./derive.StableAbi.html#InterfaceType_traits">
The list of valid traits is here
</a>
# Examples
### Using an associated constant
This example demonstrates how one can have a type parameter,
and use the value of an associated constant as the identity of the type.
*/
/**
use std::marker::PhantomData;
use abi_stable::{
abi_stability::check_layout_compatibility, marker_type::UnsafeIgnoredType, tag,
GetStaticEquivalent, StableAbi,
};
#[repr(C)]
#[derive(StableAbi)]
#[sabi(
not_stableabi(T),
bound(T: WithName),
tag = tag!( <T as WithName>::NAME )
)]
struct WithMarker<T>(UnsafeIgnoredType<T>);
impl<T> WithMarker<T> {
const NEW: Self = WithMarker(UnsafeIgnoredType::NEW);
}
trait WithName {
const NAME: &'static str;
}
#[derive(GetStaticEquivalent)]
struct Mark;
impl WithName for Mark {
const NAME: &'static str = "Mark";
}
#[derive(GetStaticEquivalent)]
struct John;
impl WithName for John {
const NAME: &'static str = "John";
}
#[derive(GetStaticEquivalent)]
struct JessiJames;
impl WithName for JessiJames {
const NAME: &'static str = "JessiJames";
}
# fn main(){
// This checks that the two types aren't considered compatible.
assert!(check_layout_compatibility(
<WithMarker<Mark> as StableAbi>::LAYOUT,
<WithMarker<John> as StableAbi>::LAYOUT,
)
.is_err());
// This checks that the two types aren't considered compatible.
assert!(check_layout_compatibility(
<WithMarker<John> as StableAbi>::LAYOUT,
<WithMarker<JessiJames> as StableAbi>::LAYOUT,
)
.is_err());
// This checks that the two types aren't considered compatible.
assert!(check_layout_compatibility(
<WithMarker<JessiJames> as StableAbi>::LAYOUT,
<WithMarker<Mark> as StableAbi>::LAYOUT,
)
.is_err());
# }
```
### Using an associated type
This example demonstrates how one can have a type parameter,
and use its associated type as a field.
```rust
use abi_stable::{std_types::RVec, StableAbi};
#[repr(C)]
#[derive(StableAbi)]
#[sabi(not_stableabi(I), bound(<I as IntoIterator>::Item : StableAbi))]
pub struct CollectedIterator<I>
where
I: IntoIterator,
{
vec: RVec<I::Item>,
}
```
[`GetStaticEquivalent_`]: abi_stable::abi_stability::get_static_equivalent::GetStaticEquivalent_
*/
pub use GetStaticEquivalent;