.. and not "UNIX domain socket.  Be consistent about the naming.

Passing it by value is actually smaller (32 bit) than the rvalue
reference (64 bit pointer), and it ensures that the object is consumed
after the call returns, no matter how the methods are implemented.

Manages memory automatically.

Use a std::list which can be appended at the end.

Replaces GLib's GError.

Eliminate the C wrappers.