Type for opening mode flags.
Bitmask type to store opening mode flags. The flag values can be any combination of the following constant member values:
bit effect ios_base::app (append) Seek to the end of the stream before each output operation. ios_base::ate (at end) Seek to the end of the stream when opening. ios_base::binary Consider stream as binary rather than text. ios_base::in Allow input operations on a stream. ios_base::out Allow output operations on a stream. ios_base::trunc (truncate) Truncate file to zero when opening.