Is there a stable library that can validate JSON against a schema?
json-schema.org provides a list of implementations. Notably C and C++ are missing.
Is there a
You can try UniversalContainer (libuc). http://www.greatpanic.com/code.html. You're looking for the container contract/schema checking class in this library. The schema format is clunky, but should handle everything you care about and provide reasonable reporting on why a particular instance fails to meet the schema.