These files are used in constraints, errors, and type deduction. They provide a way of telling the system that some types are able to fullfill these concepts, via specialization.

Current Concepts

• Writable Output Types - writable_output_traits - A type that can be serialized via write and put.
• Readable Value - nullable_value_traits - Option/Nullable/Readable like types that can be constructed, tested for whether they container a value, and read from.