Reference
C Library
IOstream Library
Strings library
STL Containers
STL Algorithms
Miscellaneous
IOstream Library
manipulators
classes:
filebuf
fstream
ifstream
ios
iostream
ios_base
istream
istringstream
ofstream
ostream
ostringstream
streambuf
stringbuf
stringstream
objects:
cerr
cin
clog
cout
types:
fpos
streamoff
streampos
streamsize
ios_base
ios_base::ios_base
ios_base::~ios_base
member classes:
ios_base::failure
ios_base::Init
member functions:
ios_base::flags
ios_base::getloc
ios_base::imbue
ios_base::iword
ios_base::precision
ios_base::pword
ios_base::register_callback
ios_base::setf
ios_base::sync_with_stdio
ios_base::unsetf
ios_base::width
ios_base::xalloc
member types:
ios_base::event
ios_base::event_callback
ios_base::fmtflags
ios_base::iostate
ios_base::openmode
ios_base::seekdir


ios_base::openmode

public member type

Type for stream opening mode flags

Bitmask type to represent stream opening mode flags.

A value of this type can be any valid combination of the following member constants:

flag valueopening mode
app(append) Set the stream's position indicator to the end of the stream before each output operation.
ate(at end) Set the stream's position indicator to the end of the stream on opening.
binary(binary) Consider stream as binary rather than text.
in(input) Allow input operations on the stream.
out(output) Allow output operations on the stream.
trunc(truncate) Any current content is discarded, assuming a length of zero on opening.

These constants are defined in the ios_base class as public members. Therefore, they can be refered to either directly by their name as ios_base members (like ios_base::in) or by using any of their inherited classes or instantiated objects, like for example ios::ate or cout.out.