+ simple epollfd
+ output file in Makefile
+ call cont_err on errors
+ check for errors
* check EINTR
+ errno description in runtime exception message
+ handle eof in main
+ delete cont_err in unsubscribe
bugfix
- invalidating iterators
+ check for event availability
+ delete copy constructor and operator= in epollfd
+ buffer
+ aread
+ handle eof and errors
+ is_eof() in buffer
* changed main using aread
+ buffer::write(int fd), changed buffer::read() to buffer::read(int fd)
+ awrite
+ aaccept
+ aoperation
+ move constructor and operator=(aoperation &&)