Four new protocol classes have been added:
- asio::generic::datagram_protocol
- asio::generic::raw_protocol
- asio::generic::seq_packet_protocol
- asio::generic::stream_protocol
These classes implement the Protocol type requirements, but allow the
user to specify the address family (e.g. AF_INET) and protocol type
(e.g. IPPROTO_TCP) at runtime.
A new endpoint class template, asio::generic::basic_endpoint, has been
added to support these new protocol classes. This endpoint can hold any
other endpoint type, provided its native representation fits into a
sockaddr_storage object.
When using C++11, it is now possible to perform move construction from a
socket (or acceptor) object to convert to the more generic protocol's
socket (or acceptor) type. If the protocol conversion is valid:
Protocol1 p1 = ...;
Protocol2 p2(p1);
then the corresponding socket conversion is allowed:
Protocol1::socket socket1(io_service);
...
Protocol2::socket socket2(std::move(socket1));
For example, one possible conversion is from a TCP socket to a generic
stream-oriented socket:
asio::ip::tcp::socket socket1(io_service);
...
asio::generic::stream_protocol::socket socket2(std::move(socket1));
The conversion is also available for move-assignment. Note that these
conversions are not limited to the newly added generic protocol classes.
User-defined protocols may take advantage of this feature by similarly
ensuring the conversion from Protocol1 to Protocol2 is valid, as above.
As a convenience, the socket acceptor's accept() and async_accept()
functions have been changed so that they can directly accept into a
different protocol's socket type, provided the protocol conversion is
valid. For example, the following is now possible:
asio::ip::tcp::acceptor acceptor(io_service);
...
asio::generic::stream_protocol::socket socket1(io_service);
acceptor.accept(socket1);
[SVN r84363]
