When writing empty objects the serializer ignores pretty printing the empty object.

[AraHaan]

When reading this line:
https://github.com/nlohmann/json/blob/develop/include/nlohmann/detail/output/serializer.hpp#L119

I think it could first check if pretty_print is true and if so write {\n} to the json file instead. This is because it annoys me when I notice the json not fully written the way I would expect when dumping it with pretty printing to the file.

[nlohmann]

No, this behavior is like this for a long time, and changing it would start other discussions about readability. Unless we have a user-provided way to control the pretty printing details, this will remain as-is.