| Value | Meaning |
|---|---|
| AUTO | Detect the requiredness from the field type: if it is nullable, treat the field as optional, if it is non-nullable, treat the field as required. This is the default used for handling structs not generated from an IDL file, and never emitted by the Thrift compiler. TReq.AUTO shouldn't be specified explicitly. |
| OPT_IN_REQ_OUT | The field is treated as optional when deserializing/receiving the struct and as required when serializing/sending. This is the Thrift default if neither "required" nor "optional" are specified in the IDL file. |
| OPTIONAL | The field is optional. |
| REQUIRED | The field is required. |
| IGNORE | Ignore the struct field when serializing/deserializing. |
Struct field requirement levels.