Optional callback which should return a newly-opened Phobos or Vibe.d TCP socket. This allows custom sockets to be used, subclassed from Phobos's or Vibe.d's sockets.
An IP address in numeric dotted form, or as a host name.
The user name to authenticate.
Desired initial database.
The set of flag bits from the server's capabilities that the client requires
Construct opened connection.
After the connection is created, and the initial invitation is received from the server client preferences can be set, and authentication can then be attempted.