📝 added note wrt. #667

README.md

@@ -539,6 +539,9 @@ Some important things:
 * Those methods **MUST** be in your type's namespace (which can be the global namespace), or the library will not be able to locate them (in this example, they are in namespace `ns`, where `person` is defined).
 * When using `get<your_type>()`, `your_type` **MUST** be [DefaultConstructible](http://en.cppreference.com/w/cpp/concept/DefaultConstructible). (There is a way to bypass this requirement described later.)
 * In function `from_json`, use function [`at()`](https://nlohmann.github.io/json/classnlohmann_1_1basic__json_a93403e803947b86f4da2d1fb3345cf2c.html#a93403e803947b86f4da2d1fb3345cf2c) to access the object values rather than `operator[]`. In case a key does not exists, `at` throws an exception that you can handle, whereas `operator[]` exhibits undefined behavior.
+* In case your type contains several `operator=` definitions, code like `your_variable = your_json;` [may not compile](https://github.com/nlohmann/json/issues/667). You need to write `your_variable = your_json.get<decltype your_variable>();` instead.
+* You do not need to add serializers or deserializers for STL types like `std::vector`: the library already implements these.
+
 
 #### How do I convert third-party types?