a slice to the resulting IP address string in dst on success or null on error. On error errno is set appropriately.
Errors: EAFNOSUPPORT: The address family is not supported (AF_INET/IPv4 or AF_INET6/IPv6).
In: - this.ai_addr must not be null: this instance should have been obtained by getaddrinfo() or manually initialised. - dst.length must be at least the required address length for the address family, INET_ADDRSTRLEN for IPv4 or INET6_ADDRSTRLEN for IPv6.
Out: If the resulting slice is not null, it slices dst from the beginning.
Obtains the current IP address in standard notation.