I suppose he refers to this... * IO * extended methods: * IO#seek supports SEEK_DATA and SEEK_HOLE as whence. * IO#seek accepts symbols (:CUR, :EN

I suppose he refers to this... * IO * extended methods: * IO#seek supports SEEK_DATA and SEEK_HOLE as whence. * IO#seek accepts symbols (:CUR, :END, :SET, :DATA, :HOLE) for 2nd argument. * IO#read_nonblock accepts optional `exception: false` to return symbols * IO#write_nonblock accepts optional `exception: false` to return symbols see https://github.com/ruby/ruby/blob/v2_1_0_preview1/NEWS https://github.com/ruby/ruby/blob/v2_1_0_preview1/NEWS