Add nlohmann::json::as_base_class

docs/examples/as_base_class.cpp

@@ -0,0 +1,40 @@
+#include <iostream>
+#include <nlohmann/json.hpp>
+
+class base_class_with_shadowed_members
+{
+  public:
+
+    int m_value = 43;
+
+    const char* type_name() const noexcept
+    {
+        return "my_name";
+    }
+};
+
+using json = nlohmann::basic_json <
+             std::map,
+             std::vector,
+             std::string,
+             bool,
+             std::int64_t,
+             std::uint64_t,
+             double,
+             std::allocator,
+             nlohmann::adl_serializer,
+             std::vector<std::uint8_t>,
+             base_class_with_shadowed_members
+             >;
+
+int main()
+{
+    json j;
+
+    //access the shadowing method
+    std::cout << j.type_name() << "\n";
+
+    //access the shadowed method and member variable
+    std::cout << j.as_base_class().type_name() << "\n";
+    std::cout << j.as_base_class().m_value << "\n";
+}

docs/examples/as_base_class.output

@@ -0,0 +1,3 @@
+null
+my_name
+43

docs/mkdocs/docs/api/basic_json/as_base_class.md

@@ -0,0 +1,32 @@
+# <small>nlohmann::basic_json::</small>as_base_class
+
+```cpp
+json_base_class_t& as_base_class();
+const json_base_class_t& as_base_class() const;
+```
+
+Returns this object casted to [json_base_class_t](json_base_class_t.md).
+
+## Return value
+
+This object casted to [json_base_class_t](json_base_class_t.md).
+
+## Examples
+
+??? example
+
+    Use `as_base_class` to access shadowed methods and member variables defined in [json_base_class_t](json_base_class_t.md).
+    
+    ```cpp
+    --8<-- "examples/as_base_class.cpp"
+    ```
+    
+    Output:
+    
+    ```json
+    --8<-- "examples/as_base_class.output"
+    ```
+
+## Version history
+
+Added in version ???.???.???

docs/mkdocs/docs/api/basic_json/index.md

@@ -151,6 +151,7 @@ The class satisfies the following concept requirements:
 - [**array**](array_t.md) (_static_) - explicitly create an array
 - [**binary**](binary.md) (_static_) - explicitly create a binary array
 - [**object**](object_t.md) (_static_) - explicitly create an object
+- [**as_base_class**](as_base_class.md) - cast this object to [json_base_class_t](json_base_class_t.md)
 
 ### Object inspection
 

docs/mkdocs/mkdocs.yml

@@ -100,6 +100,7 @@ nav:
         - 'accept': api/basic_json/accept.md
         - 'array': api/basic_json/array.md
         - 'array_t': api/basic_json/array_t.md
+        - 'as_base_class' : api/basic_json/as_base_class.md
         - 'at': api/basic_json/at.md
         - 'back': api/basic_json/back.md
         - 'begin': api/basic_json/begin.md

include/nlohmann/json.hpp

@@ -5155,6 +5155,16 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     }
 
     /// @}
+
+    json_base_class_t& as_base_class()
+    {
+        return static_cast<json_base_class_t&>(*this);
+    }
+
+    const json_base_class_t& as_base_class() const
+    {
+        return static_cast<const json_base_class_t&>(*this);
+    }
 };
 
 /// @brief user-defined to_string function for JSON values

single_include/nlohmann/json.hpp

@@ -24379,6 +24379,16 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     }
 
     /// @}
+
+    json_base_class_t& as_base_class()
+    {
+        return static_cast<json_base_class_t&>(*this);
+    }
+
+    const json_base_class_t& as_base_class() const
+    {
+        return static_cast<const json_base_class_t&>(*this);
+    }
 };
 
 /// @brief user-defined to_string function for JSON values