j3d1/json
1
0
Fork 0
Code Issues Pull requests Releases Wiki Activity

📝 comment to address #561

Browse source
This commit is contained in:
Niels Lohmann 2017-10-27 16:39:52 +02:00
parent 61cc07ff38
commit cea3f24ff9
No known key found for this signature in database
GPG key ID: 7F3CEA63AE251B69
1 changed files with 1 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

1
README.md
View file

@ -544,6 +544,7 @@ Some important things:
* 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 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. * 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. * You do not need to add serializers or deserializers for STL types like `std::vector`: the library already implements these.
* Be careful with the definition order of the `from_json`/`to_json` functions: If a type `B` has a member of type `A`, you **MUST** define `to_json(A)` before `to_json(B)`. Look at [issue 561](https://github.com/nlohmann/json/issues/561) for more details.
#### How do I convert third-party types? #### How do I convert third-party types?