|  | 
        A type X meets the InternetProtocol requirements if it satisfies
        the requirements of AcceptableProtocol, as well as the
        additional requirements listed below.
      
        In the table below, a denotes
        a (possibly const) value of type X,
        and b denotes a (possibly
        const) value of type X.
      
Table 21. InternetProtocol requirements
| expression | return type | 
                  assertion/note | 
|---|---|---|
| 
                   | 
                   | The type of a resolver for the protocol. | 
| 
                   | 
                   | Returns an object representing the IP version 4 protocol. | 
| 
                   | 
                   | Returns an object representing the IP version 6 protocol. | 
| 
                   | 
                  convertible to  | 
                  Returns  | 
| 
                   | 
                  convertible to  | 
                  Returns  |