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Diffstat (limited to 'src')
| -rw-r--r-- | src/doc/rustc-dev-guide/src/stability.md | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/src/doc/rustc-dev-guide/src/stability.md b/src/doc/rustc-dev-guide/src/stability.md index d0cee54adb6..c26d34273d7 100644 --- a/src/doc/rustc-dev-guide/src/stability.md +++ b/src/doc/rustc-dev-guide/src/stability.md @@ -181,4 +181,7 @@ the `deprecated_in_future` lint is triggered which is default `allow`, but most of the standard library raises it to a warning with `#![warn(deprecated_in_future)]`. +## unstable_feature_bound +The `#[unstable_feature_bound(foo)]` attribute can be used together with `#[unstable]` attribute to mark an `impl` of stable type and stable trait as unstable. In std/core, an item annotated with `#[unstable_feature_bound(foo)]` can only be used by another item that is also annotated with `#[unstable_feature_bound(foo)]`. Outside of std/core, using an item with `#[unstable_feature_bound(foo)]` requires the feature to be enabled with `#![feature(foo)]` attribute on the crate. Currently, only `impl`s and free functions can be annotated with `#[unstable_feature_bound]`. + [blog]: https://www.ralfj.de/blog/2018/07/19/const.html |