blob: 89b7cd422fe966a56e805cfeb21061d06fedd0c6 (
plain)
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
|
#### This error code is internal to the compiler and will not be emitted with normal Rust code.
The internal `rustc_allowed_through_unstable_modules` attribute must be used
on an item with a `stable` attribute.
Erroneous code example:
```compile_fail,E0789
// NOTE: both of these attributes are perma-unstable and should *never* be
// used outside of the compiler and standard library.
#![feature(rustc_attrs)]
#![feature(staged_api)]
#![unstable(feature = "foo_module", reason = "...", issue = "123")]
#[rustc_allowed_through_unstable_modules]
// #[stable(feature = "foo", since = "1.0")]
struct Foo;
// ^^^ error: `rustc_allowed_through_unstable_modules` attribute must be
// paired with a `stable` attribute
```
Typically when an item is marked with a `stable` attribute, the modules that
enclose the item must also be marked with `stable` attributes, otherwise the
item becomes *de facto* unstable. `#[rustc_allowed_through_unstable_modules]`
is a workaround which allows an item to "escape" its unstable parent modules.
This error occurs when an item is marked with
`#[rustc_allowed_through_unstable_modules]` but no supplementary `stable`
attribute exists. See [#99288](https://github.com/rust-lang/rust/pull/99288)
for an example of `#[rustc_allowed_through_unstable_modules]` in use.
|
