a slice to the resulting IP address string in dst on success or null either on error or if the last get() failed or get() has not been called yet; errno is then 0. On success a nul-terminator follows the sliced string so its .ptr is a C string. On error errno is set appropriately.
Errors: EAFNOSUPPORT: The address family is not supported (AF_INET/IPv4 or AF_INET6/IPv6).
Obtains the current IP address in standard notation.