Since primitive types are defined in the compiler, there's no place to attach documentation
attributes. This attribute is used by the standard library to provide a way to generate
documentation for primitive types.
+
+## `#[cfg(rustdoc)]`: Documenting platform-/feature-specific information
+
+For conditional compilation, Rustdoc treats your crate the same way the compiler does: Only things
+from the host target are available (or from the given `--target` if present), and everything else is
+"filtered out" from the crate. This can cause problems if your crate is providing different things
+on different targets and you want your documentation to reflect all the available items you
+provide.
+
+If you want to make sure an item is seen by Rustdoc regardless of what platform it's targeting,
+you can apply `#[cfg(rustdoc)]` to it. Rustdoc sets this whenever it's building documentation, so
+anything that uses that flag will make it into documentation it generates. To apply this to an item
+with other `#[cfg]` filters on it, you can write something like `#[cfg(any(windows, rustdoc))]`.
+This will preserve the item either when built normally on Windows, or when being documented
+anywhere.
+
+Please note that this feature won't be passed when building doctests.
+
+Example:
+
+```rust
+/// Token struct that can only be used on Windows.
+#[cfg(any(windows, rustdoc))]
+pub struct WindowsToken;
+/// Token struct that can only be used on Unix.
+#[cfg(any(unix, rustdoc))]
+pub struct UnixToken;
+```
+
+Here, the respective tokens can only be used by dependent crates on their respective platforms, but
+they will both appear in documentation.
(sym::target_thread_local, sym::cfg_target_thread_local, cfg_fn!(cfg_target_thread_local)),
(sym::target_has_atomic, sym::cfg_target_has_atomic, cfg_fn!(cfg_target_has_atomic)),
(sym::target_has_atomic_load_store, sym::cfg_target_has_atomic, cfg_fn!(cfg_target_has_atomic)),
- (sym::doc, sym::doc_cfg, cfg_fn!(doc_cfg)),
];
#[derive(Debug)]
--- /dev/null
+error[E0425]: cannot find value `Foo` in this scope
+ --> $DIR/cfg-rustdoc.rs:5:13
+ |
+LL | let f = Foo;
+ | ^^^ not found in this scope
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0425`.
+++ /dev/null
-error[E0658]: `cfg(doc)` is experimental and subject to change
- --> $DIR/feature-gate-doc_cfg-cfg-rustdoc.rs:1:7
- |
-LL | #[cfg(doc)]
- | ^^^
- |
- = note: for more information, see https://github.com/rust-lang/rust/issues/43781
- = help: add `#![feature(doc_cfg)]` to the crate attributes to enable
-
-error: aborting due to previous error
-
-For more information about this error, try `rustc --explain E0658`.