Return the host IPv6 address
<include/boost/url/authority_view.hpp>
ipv6_address
host_ipv6_address() const noexcept;
If the host type is host_type::ipv6 , this function returns the address as a value of type ipv6_address . Otherwise, if the host type is not an IPv6 address, it returns a default-constructed value which is equal to the unspecified address "0:0:0:0:0:0:0:0".
assert( url_view( "ftp://[::1]/" ).host_ipv6_address() == ipv6_address( "::1" ) );
IPv6address = 6( h16 ":" ) ls32
/ "::" 5( h16 ":" ) ls32
/ [ h16 ] "::" 4( h16 ":" ) ls32
/ [ *1( h16 ":" ) h16 ] "::" 3( h16 ":" ) ls32
/ [ *2( h16 ":" ) h16 ] "::" 2( h16 ":" ) ls32
/ [ *3( h16 ":" ) h16 ] "::" h16 ":" ls32
/ [ *4( h16 ":" ) h16 ] "::" ls32
/ [ *5( h16 ":" ) h16 ] "::" h16
/ [ *6( h16 ":" ) h16 ] "::"
ls32 = ( h16 ":" h16 ) / IPv4address
; least-significant 32 bits of address
h16 = 1*4HEXDIG
; 16 bits of address represented in hexadecimal