std.socket undefined UnixAddress?

[Rob T]

I'm using Linux, which supports unix domain sockets, but when I 
try to use UnixAddress it's not available.

Anyone know why?
import std.socket;

int main()
{
    Address UnixAddr = new UnixAddress( "path" ); // <- compile 
error
    return(0);
}

Error: undefined identifier UnixAddress

--rt