boost.asio: Accept IPv4 and IPv6 together

Short and simple question: I am new to boost.asio and I was wondering if it is possible to create a tcp::acceptor listening for both, IPv4 and IPv6 connections together. The tutorials on boost's homepage show something like this:

_acceptor = new tcp::acceptor(_ioService, tcp::endpoint(tcp::v4(), 3456));

where the endpoint is always specified with a specific protocol. Is it not possible to listen for IPv4 and IPv6 on the same port at the same time?