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docs/src/languages/cpp.md

@@ -156,3 +156,29 @@ You can use CodeLLDB or GDB to debug native binaries. (Make sure that your build
   }
 ]
 ```
+
+## Protocol Extensions
+
+Zed currently implements the following `clangd` [extensions](https://clangd.llvm.org/extensions):
+
+### Inactive Regions
+
+<!--Allows clients to communicate regions of code that are inactive due to preprocessor directives, such as `#if`, `#ifdef`, or `#ifndef` blocks that evaluate to false.
+Code disabled by preprocessor directives (`#if 0`, false `#ifdef` conditions, etc.) is automatically detected and visually dimmed.-->
+
+Automatically dims inactive sections of code due to preprocessor directives, such as `#if`, `#ifdef`, or `#ifndef` blocks that evaluate to false.
+
+### Switch Between Source and Header Files
+
+Allows switching between corresponding C++ source files (e.g., `.cpp`) and header files (e.g., `.h`).
+by running the command {#action editor::SwitchSourceHeader} from the command palette or by setting
+a keybinding for the `editor::SwitchSourceHeader` action.
+
+```json [settings]
+{
+  "context": "Editor",
+  "bindings": {
+    "alt-enter": "editor::SwitchSourceHeader"
+  }
+}
+```