deploy: 7c9208bfb3

api/basic_json/json_base_class_t.md

@@ -0,0 +1,45 @@
+# <small>nlohmann::basic_json::</small>json_base_class_t
+
+```cpp
+using json_base_class_t = detail::json_base_class<CustomBaseClass>;
+```
+
+The base class used to inject custom functionality into each instance of `basic_json`.
+Examples of such functionality might be metadata, additional member functions (e.g., visitors), or other application-specific code.
+
+## Template parameters
+
+`CustomBaseClass`
+:   the base class to be added to `basic_json`
+
+## Notes
+
+#### Default type
+
+The default value for `CustomBaseClass` is `void`. In this case, an
+[empty base class](https://en.cppreference.com/w/cpp/language/ebo) is used and no additional functionality is injected.
+
+#### Limitations
+
+The type `CustomBaseClass` has to be a default-constructible class.
+`basic_json` only supports copy/move construction/assignment if `CustomBaseClass` does so as well.
+
+## Examples
+
+??? example
+
+    The following code shows how to inject custom data and methods for each node.
+     
+    ```cpp
+    --8<-- "examples/json_base_class_t.cpp"
+    ```
+    
+    Output:
+    
+    ```json
+    --8<-- "examples/json_base_class_t.output"
+    ```
+
+## Version history
+
+- Added in version 3.12.0.