Construction. 

AnExampleMessage message;
AnExampleMessage message (another_message);
message.CopyFrom (another_message);

Singular Fields. 

cout << message.some_integer ();
message.set_some_integer (1234);
if (message.has_optional_integer ()) {
    message.clear_optional_integer ();
}

Repeated Fields. 

int size = messages.messages_size ();
const AnExampleMessage &message = messages.messages (1234);
AnExampleMessage *message = messages.mutable_messages (1234);
AnExampleMessage *message = messages.add_messages ();

Byte Array Serialization. 

char buffer [BUFFER_SIZE];
message.SerializeToArray (buffer, sizeof (buffer));
message.ParseFromArray (buffer, sizeof (buffer));

Standard Stream Serialization. 

message.SerializeToOstream (&stream);
message.ParseFromIstream (&stream);