Add boost::json as an alternative to rapidjson (original) (raw)

This is a feature request to add boost::json as an alternative to rapidjson/nlohmann. The boost::json API is actually quite similar to rapidjson, in many cases the code is the same but the method names are snake-case like .is_array() instead of camel-case like rapidjson's .IsArray().

Also it would be nice to be able to build Jinja2Cpp without any JSON support at all.