This is used by the error index to ensure that the samples that correspond to a given error number
properly emit that error code. However, these error codes aren't guaranteed to be the only thing
-that a piece of code emits from version to version, so this in unlikely to be stabilized in the
+that a piece of code emits from version to version, so this is unlikely to be stabilized in the
future.
Attempting to use these error numbers on stable will result in the code sample being interpreted as
In this sample, the tokens will only appear on their respective platforms, but they will both appear
in documentation.
-`#[doc(cfg(...))]` was introduced to be used by the standard library and is currently controlled by
-a feature gate. For more information, see [its chapter in the Unstable Book][unstable-doc-cfg] and
-[its tracking issue][issue-doc-cfg].
+`#[doc(cfg(...))]` was introduced to be used by the standard library and currently requires the
+`#![feature(doc_cfg)]` feature gate. For more information, see [its chapter in the Unstable
+Book][unstable-doc-cfg] and [its tracking issue][issue-doc-cfg].
[unstable-doc-cfg]: ../unstable-book/language-features/doc-cfg.html
[issue-doc-cfg]: https://github.com/rust-lang/rust/issues/43781
special marker attribute on them: `#[doc(spotlight)]`. This means that you could apply this
attribute to your own trait to include it in the "Important Traits" dialog in documentation.
-The `#[doc(spotlight)]` attribute is controlled by a feature gate. For more information, see [its
-chapter in the Unstable Book][unstable-spotlight] and [its tracking issue][issue-spotlight].
+The `#[doc(spotlight)]` attribute currently requires the `#![feature(doc_spotlight)]` feature gate.
+For more information, see [its chapter in the Unstable Book][unstable-spotlight] and [its tracking
+issue][issue-spotlight].
[unstable-spotlight]: ../unstable-book/language-features/doc-spotlight.html
[issue-spotlight]: https://github.com/rust-lang/rust/issues/45040
attribute to their `extern crate` declarations: `#[doc(masked)]`. This causes Rustdoc to "mask out"
types from these crates when building lists of trait implementations.
-The `#[doc(masked)]` attribute is intended to be used internally, and is controlled by a feature
-gate. For more information, see [its chapter in the Unstable Book][unstable-masked] and [its
-tracking issue][issue-masked].
+The `#[doc(masked)]` attribute is intended to be used internally, and requires the
+`#![feature(doc_masked)]` feature gate. For more information, see [its chapter in the Unstable
+Book][unstable-masked] and [its tracking issue][issue-masked].
[unstable-masked]: ../unstable-book/language-features/doc-masked.html
[issue-masked]: https://github.com/rust-lang/rust/issues/44027
[RFC 1990]: https://github.com/rust-lang/rfcs/pull/1990
-`#[doc(include = "...")]` is currently controlled by a feature gate. For more information, see [its
-chapter in the Unstable Book][unstable-include] and [its tracking issue][issue-include].
+`#[doc(include = "...")]` currently requires the `#![feature(external_doc)]` feature gate. For more
+information, see [its chapter in the Unstable Book][unstable-include] and [its tracking
+issue][issue-include].
[unstable-include]: ../unstable-book/language-features/external-doc.html
[issue-include]: https://github.com/rust-lang/rust/issues/44732