The bad news is: It's a nightly-only feature for now.
The good news is: docs.rs uses nightly by default.
To get this to work all you need is to enable the doc_cfg feature and apply #doc(cfg) to the item being documented
#![feature(doc_cfg)]#[doc(cfg(feature = "macros"))]pub fn test() {}Because this is a nightly-only feature, you probably don't want to enable it all the time. tokio defines the following in its Cargo.toml to only enable this feature on docs.rs:
# docs.rs-specific configuration[package.metadata.docs.rs]# document all featuresall-features = true# defines the configuration attribute `docsrs`rustdoc-args = ["--cfg", "docsrs"]and then they use
// only enables the `doc_cfg` feature when// the `docsrs` configuration attribute is defined#![cfg_attr(docsrs, feature(doc_cfg))]#[cfg_attr(docsrs, doc(cfg(feature = "macros")))]pub fn test() {}