Use doc_auto_cfg for docs generation

.github/workflows/pages.yml

@@ -12,8 +12,16 @@ jobs:
 
     steps:
     - uses: actions/checkout@v3
+    # Right now the doc_cfg and auto_doc_cfg features require nightly
+    - name: Install latest nightly
+      uses: actions-rs/toolchain@v1
+      with:
+        toolchain: nightly
+        override: true
     - name: Build documentation
-      run: cargo doc --verbose
+      run: cargo +nightly doc --verbose --all-features
+      env:
+        RUSTDOCFLAGS: --cfg docsrs
     - name: Deploy documentation
       uses: peaceiris/actions-gh-pages@v3
       with:

Cargo.toml

@@ -41,6 +41,10 @@ std = [
 ]
 vi = ["syntect"]
 
+[package.metadata.docs.rs]
+all-features = true
+rustdoc-args = ["--cfg", "docsrs"]
+
 [workspace]
 members = [
   "examples/*",

src/lib.rs

@@ -54,6 +54,11 @@
 //! });
 //! ```
 
+// If the docsrs feature is enabled, use nightly documentation features.
+//
+// This can be locally tested using RUSTDOCFLAGS="--cfg=docsrs" cargo +nightly doc --all-features
+#![cfg_attr(docsrs, feature(doc_cfg, doc_auto_cfg))]
+
 // Not interested in these lints
 #![allow(clippy::new_without_default)]
 // TODO: address occurrences and then deny