---
name: "std::basic_ios"
section: "3"
platform: "linux"
package: "gcc"
version: "16.2.1+r23+gd564253eb6c8-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/std::basic_ios"
---

# std::basic\_ios(3)

Template class basic\_ios, virtual base class for all stream classes.

## NAME

std::basic\_ios\< \_CharT, \_Traits \> - Template class basic\_ios, virtual base class for all stream classes.

## SYNOPSIS

\#include \<ios\>

Inherits **std::ios\_base**.

Inherited by **std::basic\_istream\< char \>** \[virtual\], **std::basic\_istream\< wchar\_t \>** \[virtual\], **std::basic\_ostream\< char \>** \[virtual\], **std::basic\_ostream\< wchar\_t \>** \[virtual\], **std::basic\_istream\< \_CharT, \_Traits \>** \[virtual\], and **std::basic\_ostream\< \_CharT, \_Traits \>** \[virtual\].

### Public Types

enum **event** { **erase\_event**, **imbue\_event**, **copyfmt\_event** }\
 The set of events that may be passed to an event callback.  typedef void(\* **event\_callback**) (**event** \_\_e, ios\_base &\_\_b, int \_\_i)\
 The type of an event callback function.  typedef \_Ios\_Fmtflags **fmtflags**\
 This is a bitmask type.  typedef \_Ios\_Iostate **iostate**\
 This is a bitmask type.  typedef \_Ios\_Openmode **openmode**\
 This is a bitmask type.  typedef \_Ios\_Seekdir **seekdir**\
 This is an enumerated type.

typedef \_CharT **char\_type**\
 typedef \_Traits::int\_type **int\_type**\
 typedef \_Traits::pos\_type **pos\_type**\
 typedef \_Traits::off\_type **off\_type**\
 typedef \_Traits **traits\_type**\

typedef **ctype**\< \_CharT \> **\_\_ctype\_type**\
 typedef **num\_put**\< \_CharT, **ostreambuf\_iterator**\< \_CharT, \_Traits \> \> **\_\_num\_put\_type**\
 typedef **num\_get**\< \_CharT, **istreambuf\_iterator**\< \_CharT, \_Traits \> \> **\_\_num\_get\_type**\

### Public Member Functions

**basic\_ios** (**basic\_streambuf**\< \_CharT, \_Traits \> \*\_\_sb)\
 Constructor performs initialization.  virtual **~basic\_ios** ()\
 Empty.  const **locale** & **\_M\_getloc** () const\
 Locale access.  void **\_M\_setstate** (**iostate** \_\_state)\
 bool **bad** () const\
 Fast error checking.  void **clear** (**iostate** \_\_state=**goodbit**)\
 \[Re\]sets the error state.  **basic\_ios** & **copyfmt** (const **basic\_ios** &\_\_rhs)\
 Copies fields of \_\_rhs into this.  bool **eof** () const\
 Fast error checking.  **iostate** **exceptions** () const\
 Throwing exceptions on errors.  void **exceptions** (**iostate** \_\_except)\
 Throwing exceptions on errors.  bool **fail** () const\
 Fast error checking.  **char\_type** **fill** () const\
 Retrieves the *empty* character.  **char\_type** **fill** (**char\_type** \_\_ch)\
 Sets a new *empty* character.  **fmtflags** **flags** () const\
 Access to format flags.  **fmtflags** **flags** (**fmtflags** \_\_fmtfl)\
 Setting new format flags all at once.  **locale** **getloc** () const\
 Locale access.  bool **good** () const\
 Fast error checking.  **locale** **imbue** (const **locale** &\_\_loc)\
 Moves to a new locale.  long & **iword** (int \_\_ix)\
 Access to integer array.  char **narrow** (**char\_type** \_\_c, char \_\_dfault) const\
 Squeezes characters.  **streamsize** **precision** () const\
 Flags access.  **streamsize** **precision** (**streamsize** \_\_prec)\
 Changing flags.  void \*& **pword** (int \_\_ix)\
 Access to void pointer array.  **basic\_streambuf**\< \_CharT, \_Traits \> \* **rdbuf** () const\
 Accessing the underlying buffer.  **basic\_streambuf**\< \_CharT, \_Traits \> \* **rdbuf** (**basic\_streambuf**\< \_CharT, \_Traits \> \*\_\_sb)\
 Changing the underlying buffer.  **iostate** **rdstate** () const\
 Returns the error state of the stream buffer.  void **register\_callback** (**event\_callback** \_\_fn, int \_\_index)\
 Add the callback \_\_fn with parameter \_\_index.  **fmtflags** **setf** (**fmtflags** \_\_fmtfl)\
 Setting new format flags.  **fmtflags** **setf** (**fmtflags** \_\_fmtfl, **fmtflags** \_\_mask)\
 Setting new format flags.  void **setstate** (**iostate** \_\_state)\
 Sets additional flags in the error state.  **basic\_ostream**\< \_CharT, \_Traits \> \* **tie** () const\
 Fetches the current *tied* stream.  **basic\_ostream**\< \_CharT, \_Traits \> \* **tie** (**basic\_ostream**\< \_CharT, \_Traits \> \*\_\_tiestr)\
 Ties this stream to an output stream.  void **unsetf** (**fmtflags** \_\_mask)\
 Clearing format flags.  **char\_type** **widen** (char \_\_c) const\
 Widens characters.  **streamsize** **width** () const\
 Flags access.  **streamsize** **width** (**streamsize** \_\_wide)\
 Changing flags.

**operator bool** () const\
 The quick-and-easy status check.  bool **operator!** () const\
 The quick-and-easy status check.

### Static Public Member Functions

static bool **sync\_with\_stdio** (bool \_\_sync=true)\
 Interaction with the standard C I/O objects.  static int **xalloc** ()  throw ()\
 Access to unique indices.

### Static Public Attributes

static const **openmode** **\_\_noreplace**\
 static const **fmtflags** **adjustfield**\
 A mask of left\|right\|internal. Useful for the 2-arg form of setf.  static const **openmode** **app**\
 Seek to end before each write.  static const **openmode** **ate**\
 Open and seek to end immediately after opening.  static const **iostate** **badbit**\
 Indicates a loss of integrity in an input or output sequence (such as an irrecoverable read error from a file).  static const **fmtflags** **basefield**\
 A mask of dec\|oct\|hex. Useful for the 2-arg form of setf.  static const **seekdir** **beg**\
 Request a seek relative to the beginning of the stream.  static const **openmode** **binary**\
 Perform input and output in binary mode (as opposed to text mode). This is probably not what you think it is; see https://gcc.gnu.org/onlinedocs/libstdc++/manual/fstreams.html#std.io.filestreams.binary.  static const **fmtflags** **boolalpha**\
 Insert/extract bool in alphabetic rather than numeric format.  static const **seekdir** **cur**\
 Request a seek relative to the current position within the sequence.  static const **fmtflags** **dec**\
 Converts integer input or generates integer output in decimal base.  static const **seekdir** **end**\
 Request a seek relative to the current end of the sequence.  static const **iostate** **eofbit**\
 Indicates that an input operation reached the end of an input sequence.  static const **iostate** **failbit**\
 Indicates that an input operation failed to read the expected characters, or that an output operation failed to generate the desired characters.  static const **fmtflags** **fixed**\
 Generate floating-point output in fixed-point notation.  static const **fmtflags** **floatfield**\
 A mask of scientific\|fixed. Useful for the 2-arg form of setf.  static const **iostate** **goodbit**\
 Indicates all is well.  static const **fmtflags** **hex**\
 Converts integer input or generates integer output in hexadecimal base.  static const **openmode** **in**\
 Open for input. Default for ifstream and fstream.  static const **fmtflags** **internal**\
 Adds fill characters at a designated internal point in certain generated output, or identical to right if no such point is designated.  static const **fmtflags** **left**\
 Adds fill characters on the right (final positions) of certain generated output. (I.e., the thing you print is flush left.).  static const **fmtflags** **oct**\
 Converts integer input or generates integer output in octal base.  static const **openmode** **out**\
 Open for output. Default for ofstream and fstream.  static const **fmtflags** **right**\
 Adds fill characters on the left (initial positions) of certain generated output. (I.e., the thing you print is flush right.).  static const **fmtflags** **scientific**\
 Generates floating-point output in scientific notation.  static const **fmtflags** **showbase**\
 Generates a prefix indicating the numeric base of generated integer output.  static const **fmtflags** **showpoint**\
 Generates a decimal-point character unconditionally in generated floating-point output.  static const **fmtflags** **showpos**\
 Generates a + sign in non-negative generated numeric output.  static const **fmtflags** **skipws**\
 Skips leading white space before certain input operations.  static const **openmode** **trunc**\
 Truncate an existing stream when opening. Default for ofstream.  static const **fmtflags** **unitbuf**\
 Flushes output after each output operation.  static const **fmtflags** **uppercase**\
 Replaces certain lowercase letters with their uppercase equivalents in generated output.

### Protected Types

enum { **\_S\_local\_word\_size** }\

### Protected Member Functions

**basic\_ios** ()\
 Empty.  **basic\_ios** (const basic\_ios &)=delete\
 void **\_M\_cache\_locale** (const **locale** &\_\_loc)\
 void **\_M\_call\_callbacks** (**event** \_\_ev)  throw ()\
 void **\_M\_dispose\_callbacks** (void)  throw ()\
 \_Words & **\_M\_grow\_words** (int \_\_index, bool \_\_iword)\
 void **\_M\_init** ()  throw ()\
 void **\_M\_move** (ios\_base &) noexcept\
 void **\_M\_swap** (ios\_base &\_\_rhs) noexcept\
 void **init** (**basic\_streambuf**\< \_CharT, \_Traits \> \*\_\_sb)\
 All setup is performed here.  void **move** (**basic\_ios** &&\_\_rhs)\
 void **move** (**basic\_ios** &\_\_rhs)\
 **basic\_ios** & **operator=** (const **basic\_ios** &)=delete\
 void **set\_rdbuf** (**basic\_streambuf**\< \_CharT, \_Traits \> \*\_\_sb)\
 void **swap** (**basic\_ios** &\_\_rhs) noexcept\

### Protected Attributes

\_Callback\_list \* **\_M\_callbacks**\
 const **\_\_ctype\_type** \* **\_M\_ctype**\
 **iostate** **\_M\_exception**\
 **char\_type** **\_M\_fill**\
 bool **\_M\_fill\_init**\
 **fmtflags** **\_M\_flags**\
 **locale** **\_M\_ios\_locale**\
 \_Words **\_M\_local\_word** \[\_S\_local\_word\_size\]\
 const **\_\_num\_get\_type** \* **\_M\_num\_get**\
 const **\_\_num\_put\_type** \* **\_M\_num\_put**\
 **streamsize** **\_M\_precision**\
 **basic\_streambuf**\< \_CharT, \_Traits \> \* **\_M\_streambuf**\
 **iostate** **\_M\_streambuf\_state**\
 **basic\_ostream**\< \_CharT, \_Traits \> \* **\_M\_tie**\
 **streamsize** **\_M\_width**\
 \_Words \* **\_M\_word**\
 int **\_M\_word\_size**\
 \_Words **\_M\_word\_zero**\

## Detailed Description

### template\<typename \_CharT, typename \_Traits\>

class std::basic\_ios\< \_CharT, \_Traits \>"Template class basic\_ios, virtual base class for all stream classes.

**Template Parameters**

*\_CharT* Type of character stream. \
 *\_Traits* Traits for character type, defaults to char\_traits\<\_CharT\>.

Most of the member functions called dispatched on stream objects (e.g., std::cout.foo(bar);) are consolidated in this class.

## Member Typedef Documentation

### template\<typename \_CharT, typename \_Traits\> typedef ctype\<\_CharT\> std::basic\_ios\< \_CharT, \_Traits \>::\_\_ctype\_type

These are non-standard types.

### template\<typename \_CharT, typename \_Traits\> typedef num\_get\<\_CharT, istreambuf\_iterator\<\_CharT, \_Traits\> \> std::basic\_ios\< \_CharT, \_Traits \>::\_\_num\_get\_type

These are non-standard types.

### template\<typename \_CharT, typename \_Traits\> typedef num\_put\<\_CharT, ostreambuf\_iterator\<\_CharT, \_Traits\> \> std::basic\_ios\< \_CharT, \_Traits \>::\_\_num\_put\_type

These are non-standard types.

### template\<typename \_CharT, typename \_Traits\> typedef \_CharT std::basic\_ios\< \_CharT, \_Traits \>::char\_type

These are standard types. They permit a standardized way of referring to names of (or names dependent on) the template parameters, which are specific to the implementation.

### typedef void(\* std::ios\_base::event\_callback) (event \_\_e, ios\_base &\_\_b, int \_\_i) \[inherited\]

The type of an event callback function.

**Parameters**

*\_\_e* One of the members of the event enum. \
 *\_\_b* Reference to the ios\_base object. \
 *\_\_i* The integer provided when the callback was registered.

Event callbacks are user defined functions that get called during several ios\_base and basic\_ios functions, specifically imbue(), copyfmt(), and ~ios().

### typedef \_Ios\_Fmtflags std::ios\_base::fmtflags \[inherited\]

This is a bitmask type. *\_Ios\_Fmtflags* is *implementation-defined, but it is valid to perform bitwise operations on these values and expect the Right Thing to happen. Defined objects of type fmtflags are:*

- •

  *boolalpha*

- •

  *dec*

- •

  *fixed*

- •

  *hex*

- •

  *internal*

- •

  *left*

- •

  *oct*

- •

  *right*

- •

  *scientific*

- •

  *showbase*

- •

  *showpoint*

- •

  *showpos*

- •

  *skipws*

- •

  *unitbuf*

- •

  *uppercase*

- •

  *adjustfield*

- •

  *basefield*

- •

  *floatfield*

### template\<typename \_CharT, typename \_Traits\> typedef \_Traits::int\_type std::basic\_ios\< \_CharT, \_Traits \>::int\_type

*These are standard types. They permit a standardized way of referring to names of (or names dependent on) the template parameters, which are specific to the implementation.*

### typedef \_Ios\_Iostate std::ios\_base::iostate \[inherited\]

*This is a bitmask type. \_Ios\_Iostate* is *implementation-defined, but it is valid to perform bitwise operations on these values and expect the Right Thing to happen. Defined objects of type iostate are:*

- •

  *badbit*

- •

  *eofbit*

- •

  *failbit*

- •

  *goodbit*

### template\<typename \_CharT, typename \_Traits\> typedef \_Traits::off\_type std::basic\_ios\< \_CharT, \_Traits \>::off\_type

*These are standard types. They permit a standardized way of referring to names of (or names dependent on) the template parameters, which are specific to the implementation.*

### typedef \_Ios\_Openmode std::ios\_base::openmode \[inherited\]

*This is a bitmask type. \_Ios\_Openmode* is *implementation-defined, but it is valid to perform bitwise operations on these values and expect the Right Thing to happen. Defined objects of type openmode are:*

- •

  *app*

- •

  *ate*

- •

  *binary*

- •

  *in*

- •

  *out*

- •

  *trunc*

### template\<typename \_CharT, typename \_Traits\> typedef \_Traits::pos\_type std::basic\_ios\< \_CharT, \_Traits \>::pos\_type

*These are standard types. They permit a standardized way of referring to names of (or names dependent on) the template parameters, which are specific to the implementation.*

### typedef \_Ios\_Seekdir std::ios\_base::seekdir \[inherited\]

*This is an enumerated type. \_Ios\_Seekdir* is *implementation-defined. Defined values of type seekdir are:*

- •

  *beg*

- •

  *cur, equivalent to* SEEK\_CUR *in the C standard library.*

- •

  *end, equivalent to* SEEK\_END *in the C standard library.*

### template\<typename \_CharT, typename \_Traits\> typedef \_Traits std::basic\_ios\< \_CharT, \_Traits \>::traits\_type

*These are standard types. They permit a standardized way of referring to names of (or names dependent on) the template parameters, which are specific to the implementation.*

## Member Enumeration Documentation

### enum std::ios\_base::event \[inherited\]

*The set of events that may be passed to an event callback. erase\_event is used during ~ios() and copyfmt(). imbue\_event is used during imbue(). copyfmt\_event is used during copyfmt().*

## Constructor & Destructor Documentation

### template\<typename \_CharT, typename \_Traits\> std::basic\_ios\< \_CharT, \_Traits \>::basic\_ios (basic\_streambuf\< \_CharT, \_Traits \> \* \_\_sb) \[inline\], \[explicit\]

*Constructor performs initialization. The parameter is passed by derived streams.*

*Referenced by* **copyfmt()***.*

### template\<typename \_CharT, typename \_Traits\> virtual std::basic\_ios\< \_CharT, \_Traits \>::~basic\_ios () \[inline\], \[virtual\]

*Empty. The destructor does nothing. More specifically, it does not destroy the streambuf held by rdbuf().*

### template\<typename \_CharT, typename \_Traits\> std::basic\_ios\< \_CharT, \_Traits \>::basic\_ios () \[inline\], \[protected\]

*Empty. The default constructor does nothing and is not normally accessible to users.*

## Member Function Documentation

### const locale & std::ios\_base::\_M\_getloc () const \[inline\], \[inherited\]

*Locale access.*

**Returns**

*A reference to the current locale.*

*Like getloc above, but returns a reference instead of generating a copy.*

*Referenced by* **std::money\_get\< \_CharT, \_InIter \>::do\_get()***,* **std::num\_get\< \_CharT, \_InIter \>::do\_get()***,* **std::time\_get\< \_CharT, \_InIter \>::do\_get()***,* **std::time\_get\< \_CharT, \_InIter \>::do\_get\_date()***,* **std::time\_get\< \_CharT, \_InIter \>::do\_get\_monthname()***,* **std::time\_get\< \_CharT, \_InIter \>::do\_get\_time()***,* **std::time\_get\< \_CharT, \_InIter \>::do\_get\_weekday()***,* **std::time\_get\< \_CharT, \_InIter \>::do\_get\_year()***,* **std::num\_put\< \_CharT, \_OutIter \>::do\_put()***,* **std::time\_put\< \_CharT, \_OutIter \>::do\_put()***,* **std::time\_get\< \_CharT, \_InIter \>::get()***, and* **std::time\_put\< \_CharT, \_OutIter \>::put()***.*

### template\<typename \_CharT, typename \_Traits\> bool std::basic\_ios\< \_CharT, \_Traits \>::bad () const \[inline\], \[nodiscard\]

*Fast error checking.*

**Returns**

*True if the badbit is set.*

*Note that other iostate flags may also be set.*

*Referenced by* **std::basic\_ostream\< \_CharT, \_Traits \>::sentry::sentry()***.*

### template\<typename \_CharT, typename \_Traits\> void std::basic\_ios\< \_CharT, \_Traits \>::clear (iostate \_\_state = goodbit)

*\[Re\]sets the error state.*

**Parameters**

*\_\_state The new state flag(s) to set.*

*See std::ios\_base::iostate for the possible bit values. Most users will not need to pass an argument.*

*References* **std::ios\_base::badbit***,* **exceptions()***,* **rdbuf()***, and* **rdstate()***.*

*Referenced by* **std::basic\_ios\< char\_type, traits\_type \>::exceptions()***,* **std::basic\_fstream\< char \>::open()***,* **std::basic\_fstream\< char \>::open()***,* **std::basic\_ifstream\< char \>::open()***,* **std::basic\_ifstream\< char \>::open()***,* **std::basic\_ofstream\< char \>::open()***,* **std::basic\_ofstream\< char \>::open()***,* **std::\_\_detail::operator\>\>()***,* **std::basic\_istream\< \_CharT, \_Traits \>::putback()***,* **rdbuf()***,* **std::basic\_istream\< \_CharT, \_Traits \>::seekg()***,* **std::basic\_istream\< \_CharT, \_Traits \>::seekg()***,* **std::basic\_ios\< char\_type, traits\_type \>::setstate()***, and* **std::basic\_istream\< \_CharT, \_Traits \>::unget()***.*

### template\<typename \_CharT, typename \_Traits\> basic\_ios\< \_CharT, \_Traits \> & std::basic\_ios\< \_CharT, \_Traits \>::copyfmt (const basic\_ios\< \_CharT, \_Traits \> & \_\_rhs)

*Copies fields of \_\_rhs into this.*

**Parameters**

*\_\_rhs The source values for the copies.*

**Returns**

*Reference to this object.*

*All fields of \_\_rhs are copied into this object except that rdbuf() and rdstate() remain unchanged. All values in the pword and iword arrays are copied. Before copying, each callback is invoked with erase\_event. After copying, each (new) callback is invoked with copyfmt\_event. The final step is to copy exceptions().*

*References* **basic\_ios()***,* **std::\_\_addressof()***,* **exceptions()***,* **fill()***,* **std::ios\_base::flags()***,* **std::ios\_base::getloc()***,* **std::ios\_base::precision()***,* **tie()***,* **std::tie()***, and* **std::ios\_base::width()***.*

### template\<typename \_CharT, typename \_Traits\> bool std::basic\_ios\< \_CharT, \_Traits \>::eof () const \[inline\], \[nodiscard\]

*Fast error checking.*

**Returns**

*True if the eofbit is set.*

*Note that other iostate flags may also be set.*

### template\<typename \_CharT, typename \_Traits\> iostate std::basic\_ios\< \_CharT, \_Traits \>::exceptions () const \[inline\], \[nodiscard\]

*Throwing exceptions on errors.*

**Returns**

*The current exceptions mask.*

*This changes nothing in the stream. See the one-argument version of exceptions(iostate) for the meaning of the return value.*

*Referenced by* **clear()***, and* **copyfmt()***.*

### template\<typename \_CharT, typename \_Traits\> void std::basic\_ios\< \_CharT, \_Traits \>::exceptions (iostate \_\_except) \[inline\]

*Throwing exceptions on errors.*

**Parameters**

*\_\_except The new exceptions mask.*

*By default, error flags are set silently. You can set an exceptions mask for each stream; if a bit in the mask becomes set in the error flags, then an exception of type std::ios\_base::failure is thrown.*

*If the error flag is already set when the exceptions mask is added, the exception is immediately thrown. Try running the following under GCC 3.1 or later:*

```
#include <iostream>
#include <fstream>
#include <exception>
int main()
{
    std::set_terminate (__gnu_cxx::__verbose_terminate_handler);
    std::ifstream f ("/etc/motd");
    std::cerr << "Setting badbit\n";
    f.setstate (std::ios_base::badbit);
    std::cerr << "Setting exception mask\n";
    f.exceptions (std::ios_base::badbit);
}
```

### template\<typename \_CharT, typename \_Traits\> bool std::basic\_ios\< \_CharT, \_Traits \>::fail () const \[inline\], \[nodiscard\]

*Fast error checking.*

**Returns**

*True if either the badbit or the failbit is set.*

*Checking the badbit in fail() is historical practice. Note that other iostate flags may also be set.*

*Referenced by* **std::basic\_ios\< char\_type, traits\_type \>::operator bool()***,* **std::basic\_ios\< char\_type, traits\_type \>::operator!()***,* **std::basic\_istream\< \_CharT, \_Traits \>::seekg()***,* **std::basic\_istream\< \_CharT, \_Traits \>::seekg()***,* **std::basic\_ostream\< \_CharT, \_Traits \>::seekp()***,* **std::basic\_ostream\< \_CharT, \_Traits \>::seekp()***,* **std::basic\_istream\< \_CharT, \_Traits \>::tellg()***, and* **std::basic\_ostream\< \_CharT, \_Traits \>::tellp()***.*

### template\<typename \_CharT, typename \_Traits\> char\_type std::basic\_ios\< \_CharT, \_Traits \>::fill () const \[inline\], \[nodiscard\]

*Retrieves the empty character.*

**Returns**

*The current fill character.*

*It defaults to a space (' ') in the current locale.*

*Referenced by* **copyfmt()***, and* **std::philox\_engine\< uint\_fast32\_t, 32, 4, 10, 0xCD9E8D57, 0x9E3779B9, 0xD2511F53, 0xBB67AE85 \>::operator\<\<***.*

### template\<typename \_CharT, typename \_Traits\> char\_type std::basic\_ios\< \_CharT, \_Traits \>::fill (char\_type \_\_ch) \[inline\]

*Sets a new empty character.*

**Parameters**

*\_\_ch The new character.*

**Returns**

*The previous fill character.*

*The fill character is used to fill out space when P+ characters have been requested (e.g., via setw), Q characters are actually used, and Q\<P. It defaults to a space (' ') in the current locale.*

### fmtflags std::ios\_base::flags () const \[inline\], \[nodiscard\], \[inherited\]

*Access to format flags.*

**Returns**

*The format control flags for both input and output.*

*Referenced by* **std::basic\_ios\< \_CharT, \_Traits \>::copyfmt()***,* **std::num\_get\< \_CharT, \_InIter \>::do\_get()***,* **std::num\_get\< \_CharT, \_InIter \>::do\_get()***,* **std::num\_put\< \_CharT, \_OutIter \>::do\_put()***,* **std::num\_put\< \_CharT, \_OutIter \>::do\_put()***,* **std::chrono::operator\<\<()***,* **std::philox\_engine\< uint\_fast32\_t, 32, 4, 10, 0xCD9E8D57, 0x9E3779B9, 0xD2511F53, 0xBB67AE85 \>::operator\<\<***,* **std::\_\_detail::operator\>\>()***,* **std::operator\>\>()***,* **std::operator\>\>()***,* **std::operator\>\>()***,* **std::operator\>\>()***,* **std::operator\>\>()***,* **std::operator\>\>()***,* **std::operator\>\>()***, and* **std::philox\_engine\< uint\_fast32\_t, 32, 4, 10, 0xCD9E8D57, 0x9E3779B9, 0xD2511F53, 0xBB67AE85 \>::operator\>\>***.*

### fmtflags std::ios\_base::flags (fmtflags \_\_fmtfl) \[inline\], \[inherited\]

*Setting new format flags all at once.*

**Parameters**

*\_\_fmtfl The new flags to set.*

**Returns**

*The previous format control flags.*

*This function overwrites all the format flags with \_\_fmtfl.*

### locale std::ios\_base::getloc () const \[inline\], \[nodiscard\], \[inherited\]

*Locale access.*

**Returns**

*A copy of the current locale.*

*If* imbue(loc) *has previously been called, then this function returns* loc*. Otherwise, it returns a copy of* std::locale()*, the global C++ locale.*

*Referenced by* **std::basic\_ios\< \_CharT, \_Traits \>::copyfmt()***,* **std::money\_put\< \_CharT, \_OutIter \>::do\_put()***,* **std::basic\_ios\< \_CharT, \_Traits \>::imbue()***,* **std::chrono::operator\<\<()***,* **std::operator\>\>()***,* **std::operator\>\>()***, and* **std::ws()***.*

### template\<typename \_CharT, typename \_Traits\> bool std::basic\_ios\< \_CharT, \_Traits \>::good () const \[inline\], \[nodiscard\]

*Fast error checking.*

**Returns**

*True if no error flags are set.*

*A wrapper around rdstate.*

*Referenced by* **std::basic\_istream\< \_CharT, \_Traits \>::sentry::sentry()***,* **std::basic\_ostream\< \_CharT, \_Traits \>::sentry::sentry()***, and* **std::\_\_detail::operator\>\>()***.*

### template\<typename \_CharT, typename \_Traits\> locale std::basic\_ios\< \_CharT, \_Traits \>::imbue (const locale & \_\_loc)

*Moves to a new locale.*

**Parameters**

*\_\_loc The new locale.*

**Returns**

*The previous locale.*

*Calls* ios\_base::imbue(loc)*, and if a stream buffer is associated with this stream, calls that buffer's* pubimbue(loc)*.*

*Additional l10n notes are at https://gcc.gnu.org/onlinedocs/libstdc++/manual/localization.html*

*References* **std::ios\_base::getloc()***,* **std::ios\_base::imbue()***, and* **rdbuf()***.*

*Referenced by* **std::chrono::operator\<\<()***.*

### template\<typename \_CharT, typename \_Traits\> void std::basic\_ios\< \_CharT, \_Traits \>::init (basic\_streambuf\< \_CharT, \_Traits \> \* \_\_sb) \[protected\]

*All setup is performed here. This is called from the public constructor. It is not virtual and cannot be redefined.*

*Referenced by* **std::basic\_fstream\< char \>::basic\_fstream()***,* **std::basic\_fstream\< char \>::basic\_fstream()***,* **std::basic\_fstream\< char \>::basic\_fstream()***,* **std::basic\_ifstream\< char \>::basic\_ifstream()***,* **std::basic\_ifstream\< char \>::basic\_ifstream()***,* **std::basic\_ifstream\< char \>::basic\_ifstream()***,* **std::basic\_ios\< char\_type, traits\_type \>::basic\_ios()***,* **std::basic\_istream\< char\_type, traits\_type \>::basic\_istream()***,* **std::basic\_istringstream\< char \>::basic\_istringstream()***,* **std::basic\_istringstream\< char \>::basic\_istringstream()***,* **std::basic\_istringstream\< char \>::basic\_istringstream()***,* **std::basic\_ofstream\< char \>::basic\_ofstream()***,* **std::basic\_ofstream\< char \>::basic\_ofstream()***,* **std::basic\_ofstream\< char \>::basic\_ofstream()***,* **std::basic\_ostream\< char\_type, traits\_type \>::basic\_ostream()***,* **std::basic\_ostringstream\< char \>::basic\_ostringstream()***,* **std::basic\_ostringstream\< char \>::basic\_ostringstream()***,* **std::basic\_ostringstream\< char \>::basic\_ostringstream()***,* **std::basic\_stringstream\< char \>::basic\_stringstream()***,* **std::basic\_stringstream\< char \>::basic\_stringstream()***, and* **std::basic\_stringstream\< char \>::basic\_stringstream()***.*

### long & std::ios\_base::iword (int \_\_ix) \[inline\], \[inherited\]

*Access to integer array.*

**Parameters**

*\_\_ix Index into the array.*

**Returns**

*A reference to an integer associated with the index.*

*The iword function provides access to an array of integers that can be used for any purpose. The array grows as required to hold the supplied index. All integers in the array are initialized to 0.*

*The implementation reserves several indices. You should use xalloc to obtain an index that is safe to use. Also note that since the array can grow dynamically, it is not safe to hold onto the reference.*

*References* **iword()***.*

*Referenced by* **iword()***.*

### template\<typename \_CharT, typename \_Traits\> char std::basic\_ios\< \_CharT, \_Traits \>::narrow (char\_type \_\_c, char \_\_dfault) const \[inline\]

*Squeezes characters.*

**Parameters**

*\_\_c The character to narrow.* \
 *\_\_dfault The character to narrow.*

**Returns**

*The narrowed character.*

*Maps a character of* char\_type *to a character of* char*, if possible.*

*Returns the result of*

```
std::use_facet<ctype<char_type> >(getloc()).narrow(c,dfault)
```

*Additional l10n notes are at https://gcc.gnu.org/onlinedocs/libstdc++/manual/localization.html*

### template\<typename \_CharT, typename \_Traits\> std::basic\_ios\< \_CharT, \_Traits \>::operator bool () const \[inline\], \[explicit\], \[nodiscard\]

*The quick-and-easy status check. This allows you to write constructs such as* if (!a\_stream) ... *and* while (a\_stream) ...

### template\<typename \_CharT, typename \_Traits\> bool std::basic\_ios\< \_CharT, \_Traits \>::operator! () const \[inline\], \[nodiscard\]

*The quick-and-easy status check. This allows you to write constructs such as* if (!a\_stream) ... *and* while (a\_stream) ...

### streamsize std::ios\_base::precision () const \[inline\], \[nodiscard\], \[inherited\]

*Flags access.*

**Returns**

*The precision to generate on certain output operations.*

*Be careful if you try to give a definition of precision here; see DR 189.*

*Referenced by* **std::basic\_ios\< \_CharT, \_Traits \>::copyfmt()***, and* **std::chrono::operator\<\<()***.*

### streamsize std::ios\_base::precision (streamsize \_\_prec) \[inline\], \[inherited\]

*Changing flags.*

**Parameters**

*\_\_prec The new precision value.*

**Returns**

*The previous value of precision().*

### void \*& std::ios\_base::pword (int \_\_ix) \[inline\], \[inherited\]

*Access to void pointer array.*

**Parameters**

*\_\_ix Index into the array.*

**Returns**

*A reference to a void\* associated with the index.*

*The pword function provides access to an array of pointers that can be used for any purpose. The array grows as required to hold the supplied index. All pointers in the array are initialized to 0.*

*The implementation reserves several indices. You should use xalloc to obtain an index that is safe to use. Also note that since the array can grow dynamically, it is not safe to hold onto the reference.*

### template\<typename \_CharT, typename \_Traits\> basic\_streambuf\< \_CharT, \_Traits \> \* std::basic\_ios\< \_CharT, \_Traits \>::rdbuf () const \[inline\], \[nodiscard\]

*Accessing the underlying buffer.*

**Returns**

*The current stream buffer.*

*This does not change the state of the stream.*

*Referenced by* **clear()***,* **std::basic\_ostream\< \_CharT, \_Traits \>::flush()***,* **std::basic\_istream\< \_CharT, \_Traits \>::get()***,* **std::basic\_istream\< \_CharT, \_Traits \>::get()***,* **std::basic\_istream\< \_CharT, \_Traits \>::get()***,* **std::basic\_istream\< \_CharT, \_Traits \>::get()***,* **std::getline()***,* **std::getline()***,* **std::basic\_istream\< \_CharT, \_Traits \>::ignore()***,* **std::basic\_istream\< \_CharT, \_Traits \>::ignore()***,* **imbue()***,* **std::operator\<\<()***,* **std::basic\_istream\< \_CharT, \_Traits \>::operator\>\>()***,* **std::operator\>\>()***,* **std::operator\>\>()***,* **std::operator\>\>()***,* **std::tr2::operator\>\>()***,* **std::basic\_istream\< \_CharT, \_Traits \>::peek()***,* **std::basic\_ostream\< \_CharT, \_Traits \>::put()***,* **std::basic\_istream\< \_CharT, \_Traits \>::putback()***,* **std::basic\_istream\< \_CharT, \_Traits \>::read()***,* **std::basic\_istream\< \_CharT, \_Traits \>::readsome()***,* **std::basic\_istream\< \_CharT, \_Traits \>::seekg()***,* **std::basic\_istream\< \_CharT, \_Traits \>::seekg()***,* **std::basic\_ostream\< \_CharT, \_Traits \>::seekp()***,* **std::basic\_ostream\< \_CharT, \_Traits \>::seekp()***,* **std::basic\_istream\< \_CharT, \_Traits \>::sync()***,* **std::basic\_istream\< \_CharT, \_Traits \>::tellg()***,* **std::basic\_ostream\< \_CharT, \_Traits \>::tellp()***,* **std::basic\_istream\< \_CharT, \_Traits \>::unget()***, and* **std::ws()***.*

### template\<typename \_CharT, typename \_Traits\> basic\_streambuf\< \_CharT, \_Traits \> \* std::basic\_ios\< \_CharT, \_Traits \>::rdbuf (basic\_streambuf\< \_CharT, \_Traits \> \* \_\_sb)

*Changing the underlying buffer.*

**Parameters**

*\_\_sb The new stream buffer.*

**Returns**

*The previous stream buffer.*

*Associates a new buffer with the current stream, and clears the error state.*

*Due to historical accidents which the LWG refuses to correct, the I/O library suffers from a design error: this function is hidden in derived classes by overrides of the zero-argument* rdbuf()*, which is non-virtual for hysterical raisins. As a result, you must use explicit qualifications to access this function via any derived class. For example:*

```
std::fstream     foo;         // or some other derived type
std::streambuf*  p = .....;
foo.ios::rdbuf(p);            // ios == basic_ios<char>
```

*References* **clear()***.*

### template\<typename \_CharT, typename \_Traits\> iostate std::basic\_ios\< \_CharT, \_Traits \>::rdstate () const \[inline\], \[nodiscard\]

*Returns the error state of the stream buffer.*

**Returns**

*A bit pattern (well, isn't everything?)*

*See std::ios\_base::iostate for the possible bit values. Most users will call one of the interpreting wrappers, e.g., good().*

*Referenced by* **std::basic\_ios\< char\_type, traits\_type \>::bad()***,* **clear()***,* **std::basic\_ios\< char\_type, traits\_type \>::eof()***,* **std::basic\_ios\< char\_type, traits\_type \>::fail()***,* **std::basic\_ios\< char\_type, traits\_type \>::good()***,* **std::basic\_istream\< \_CharT, \_Traits \>::putback()***,* **std::basic\_istream\< \_CharT, \_Traits \>::seekg()***,* **std::basic\_istream\< \_CharT, \_Traits \>::seekg()***,* **std::basic\_ios\< char\_type, traits\_type \>::setstate()***, and* **std::basic\_istream\< \_CharT, \_Traits \>::unget()***.*

### void std::ios\_base::register\_callback (event\_callback \_\_fn, int \_\_index) \[inherited\]

*Add the callback \_\_fn with parameter \_\_index.*

**Parameters**

*\_\_fn The function to add.* \
 *\_\_index The integer to pass to the function when invoked.*

*Registers a function as an event callback with an integer parameter to be passed to the function when invoked. Multiple copies of the function are allowed. If there are multiple callbacks, they are invoked in the order they were registered.*

### fmtflags std::ios\_base::setf (fmtflags \_\_fmtfl) \[inline\], \[inherited\]

*Setting new format flags.*

**Parameters**

*\_\_fmtfl Additional flags to set.*

**Returns**

*The previous format control flags.*

*This function sets additional flags in format control. Flags that were previously set remain set.*

*Referenced by* **std::\_\_detail::operator\>\>()***.*

### fmtflags std::ios\_base::setf (fmtflags \_\_fmtfl, fmtflags \_\_mask) \[inline\], \[inherited\]

*Setting new format flags.*

**Parameters**

*\_\_fmtfl Additional flags to set.* \
 *\_\_mask The flags mask for fmtfl.*

**Returns**

*The previous format control flags.*

*This function clears mask in the format flags, then sets fmtfl* & *mask. An example mask is* ios\_base::adjustfield*.*

### template\<typename \_CharT, typename \_Traits\> void std::basic\_ios\< \_CharT, \_Traits \>::setstate (iostate \_\_state) \[inline\]

*Sets additional flags in the error state.*

**Parameters**

*\_\_state The additional state flag(s) to set.*

*See std::ios\_base::iostate for the possible bit values.*

*Referenced by* **std::basic\_ostream\< \_CharT, \_Traits \>::sentry::sentry()***,* **std::basic\_fstream\< char \>::close()***,* **std::basic\_ifstream\< char \>::close()***,* **std::basic\_ofstream\< char \>::close()***,* **std::basic\_ostream\< \_CharT, \_Traits \>::flush()***,* **std::basic\_istream\< \_CharT, \_Traits \>::get()***,* **std::basic\_istream\< \_CharT, \_Traits \>::get()***,* **std::getline()***,* **std::getline()***,* **std::basic\_fstream\< char \>::open()***,* **std::basic\_fstream\< char \>::open()***,* **std::basic\_ifstream\< char \>::open()***,* **std::basic\_ifstream\< char \>::open()***,* **std::basic\_ofstream\< char \>::open()***,* **std::basic\_ofstream\< char \>::open()***,* **std::basic\_ostream\< \_CharT, \_Traits \>::operator\<\<()***,* **std::operator\<\<()***,* **std::operator\<\<()***,* **std::basic\_istream\< \_CharT, \_Traits \>::operator\>\>()***,* **std::basic\_istream\< \_CharT, \_Traits \>::operator\>\>()***,* **std::operator\>\>()***,* **std::operator\>\>()***,* **std::operator\>\>()***,* **std::tr2::operator\>\>()***,* **std::basic\_ostream\< \_CharT, \_Traits \>::put()***,* **std::basic\_istream\< \_CharT, \_Traits \>::putback()***,* **std::basic\_istream\< \_CharT, \_Traits \>::read()***,* **std::basic\_istream\< \_CharT, \_Traits \>::readsome()***,* **std::basic\_istream\< \_CharT, \_Traits \>::seekg()***,* **std::basic\_istream\< \_CharT, \_Traits \>::seekg()***,* **std::basic\_ostream\< \_CharT, \_Traits \>::seekp()***,* **std::basic\_ostream\< \_CharT, \_Traits \>::seekp()***,* **std::basic\_istream\< \_CharT, \_Traits \>::sync()***, and* **std::ws()***.*

### bool std::ios\_base::sync\_with\_stdio (bool \_\_sync = true) \[static\], \[inherited\]

*Interaction with the standard C I/O objects.*

**Parameters**

*\_\_sync Whether to synchronize or not.*

**Returns**

*True if the standard streams were previously synchronized.*

*The synchronization referred to is only that between the standard C facilities (e.g., stdout) and the standard C++ objects (e.g., cout). User-declared streams are unaffected. See https://gcc.gnu.org/onlinedocs/libstdc++/manual/fstreams.html#std.io.filestreams.binary*

### template\<typename \_CharT, typename \_Traits\> basic\_ostream\< \_CharT, \_Traits \> \* std::basic\_ios\< \_CharT, \_Traits \>::tie () const \[inline\], \[nodiscard\]

*Fetches the current tied stream.*

**Returns**

*A pointer to the tied stream, or NULL if the stream is not tied.*

*A stream may be tied (or synchronized) to a second output stream. When this stream performs any I/O, the tied stream is first flushed. For example,* std::cin *is tied to* std::cout*.*

*Referenced by* **std::basic\_ostream\< \_CharT, \_Traits \>::sentry::sentry()***, and* **copyfmt()***.*

### template\<typename \_CharT, typename \_Traits\> basic\_ostream\< \_CharT, \_Traits \> \* std::basic\_ios\< \_CharT, \_Traits \>::tie (basic\_ostream\< \_CharT, \_Traits \> \* \_\_tiestr) \[inline\]

*Ties this stream to an output stream.*

**Parameters**

*\_\_tiestr The output stream.*

**Returns**

*The previously tied output stream, or NULL if the stream was not tied.*

*This sets up a new tie; see tie() for more.*

### void std::ios\_base::unsetf (fmtflags \_\_mask) \[inline\], \[inherited\]

*Clearing format flags.*

**Parameters**

*\_\_mask The flags to unset.*

*This function clears \_\_mask in the format flags.*

### template\<typename \_CharT, typename \_Traits\> char\_type std::basic\_ios\< \_CharT, \_Traits \>::widen (char \_\_c) const \[inline\]

*Widens characters.*

**Parameters**

*\_\_c The character to widen.*

**Returns**

*The widened character.*

*Maps a character of* char *to a character of* char\_type*.*

*Returns the result of*

```
std::use_facet<ctype<char_type> >(getloc()).widen(c)
```

*Additional l10n notes are at https://gcc.gnu.org/onlinedocs/libstdc++/manual/localization.html*

*Referenced by* **std::endl()***,* **std::basic\_ios\< char\_type, traits\_type \>::fill()***,* **std::basic\_istream\< char\_type, traits\_type \>::get()***,* **std::basic\_istream\< char\_type, traits\_type \>::get()***,* **std::basic\_istream\< char\_type, traits\_type \>::getline()***,* **std::getline()***,* **std::getline()***,* **std::operator\<\<()***,* **std::operator\<\<()***,* **std::philox\_engine\< uint\_fast32\_t, 32, 4, 10, 0xCD9E8D57, 0x9E3779B9, 0xD2511F53, 0xBB67AE85 \>::operator\<\<***, and* **std::tr2::operator\>\>()***.*

### streamsize std::ios\_base::width () const \[inline\], \[nodiscard\], \[inherited\]

*Flags access.*

**Returns**

*The minimum field width to generate on output operations.*

*Minimum field width refers to the number of characters.*

*Referenced by* **std::basic\_ios\< \_CharT, \_Traits \>::copyfmt()***,* **std::num\_put\< \_CharT, \_OutIter \>::do\_put()***,* **std::operator\>\>()***, and* **std::operator\>\>()***.*

### streamsize std::ios\_base::width (streamsize \_\_wide) \[inline\], \[inherited\]

*Changing flags.*

**Parameters**

*\_\_wide The new width value.*

**Returns**

*The previous value of width().*

### int std::ios\_base::xalloc () \[static\], \[inherited\]

*Access to unique indices.*

**Returns**

*An integer different from all previous calls.*

*This function returns a unique integer every time it is called. It can be used for any purpose, but is primarily intended to be a unique index for the iword and pword functions. The expectation is that an application calls xalloc in order to obtain an index in the iword and pword arrays that can be used without fear of conflict.*

*The implementation maintains a static variable that is incremented and returned on each invocation. xalloc is guaranteed to return an index that is safe to use in the iword and pword arrays.*

## Member Data Documentation

### const fmtflags std::ios\_base::adjustfield \[static\], \[inherited\]

*A mask of left\|right\|internal. Useful for the 2-arg form of* setf*.*

*Referenced by* **std::num\_put\< \_CharT, \_OutIter \>::do\_put()***,* **std::internal()***,* **std::left()***, and* **std::right()***.*

### const openmode std::ios\_base::app \[static\], \[inherited\]

*Seek to end before each write.*

*Referenced by* **std::basic\_filebuf\< char\_type, traits\_type \>::\_M\_set\_buffer()***,* **std::basic\_filebuf\< \_CharT, \_Traits \>::overflow()***, and* **std::basic\_filebuf\< \_CharT, \_Traits \>::xsputn()***.*

### const openmode std::ios\_base::ate \[static\], \[inherited\]

*Open and seek to end immediately after opening.*

*Referenced by* **std::basic\_filebuf\< \_CharT, \_Traits \>::open()***.*

### const iostate std::ios\_base::badbit \[static\], \[inherited\]

*Indicates a loss of integrity in an input or output sequence (such as an irrecoverable read error from a file).*

*Referenced by* **std::basic\_istream\< \_CharT, \_Traits \>::sentry::sentry()***,* **std::basic\_ostream\< \_CharT, \_Traits \>::sentry::~sentry()***,* **std::basic\_ios\< \_CharT, \_Traits \>::clear()***,* **std::basic\_ostream\< \_CharT, \_Traits \>::flush()***,* **std::basic\_iostream\< char\_type, traits\_type \>::get()***,* **std::basic\_istream\< \_CharT, \_Traits \>::get()***,* **std::basic\_istream\< \_CharT, \_Traits \>::get()***,* **std::basic\_iostream\< char\_type, traits\_type \>::operator\<\<()***,* **std::basic\_ostream\< \_CharT, \_Traits \>::operator\<\<()***,* **std::basic\_istream\< \_CharT, \_Traits \>::operator\>\>()***,* **std::operator\>\>()***,* **std::basic\_ostream\< \_CharT, \_Traits \>::put()***,* **std::basic\_istream\< \_CharT, \_Traits \>::putback()***,* **std::basic\_istream\< \_CharT, \_Traits \>::read()***,* **std::basic\_istream\< \_CharT, char\_traits\< \_CharT \> \>::read()***,* **std::basic\_istream\< \_CharT, \_Traits \>::readsome()***,* **std::basic\_istream\< \_CharT, \_Traits \>::seekg()***,* **std::basic\_istream\< \_CharT, \_Traits \>::seekg()***,* **std::basic\_istream\< \_CharT, \_Traits \>::sync()***,* **std::basic\_istream\< \_CharT, \_Traits \>::tellg()***,* **std::basic\_istream\< \_CharT, \_Traits \>::unget()***, and* **std::ws()***.*

### const fmtflags std::ios\_base::basefield \[static\], \[inherited\]

*A mask of dec\|oct\|hex. Useful for the 2-arg form of* setf*.*

*Referenced by* **std::dec()***,* **std::num\_get\< \_CharT, \_InIter \>::do\_get()***,* **std::num\_put\< \_CharT, \_OutIter \>::do\_put()***,* **std::hex()***, and* **std::oct()***.*

### const seekdir std::ios\_base::beg \[static\], \[inherited\]

*Request a seek relative to the beginning of the stream.*

*Referenced by* **std::basic\_filebuf\< \_CharT, \_Traits \>::seekpos()***.*

### const openmode std::ios\_base::binary \[static\], \[inherited\]

*Perform input and output in binary mode (as opposed to text mode). This is probably not what you think it is; see https://gcc.gnu.org/onlinedocs/libstdc++/manual/fstreams.html#std.io.filestreams.binary.*

*Referenced by* **std::basic\_filebuf\< \_CharT, \_Traits \>::showmanyc()***.*

### const fmtflags std::ios\_base::boolalpha \[static\], \[inherited\]

*Insert/extract* bool *in alphabetic rather than numeric format.*

*Referenced by* **std::boolalpha()***,* **std::num\_get\< \_CharT, \_InIter \>::do\_get()***,* **std::num\_put\< \_CharT, \_OutIter \>::do\_put()***, and* **std::noboolalpha()***.*

### const seekdir std::ios\_base::cur \[static\], \[inherited\]

*Request a seek relative to the current position within the sequence.*

*Referenced by* **std::basic\_filebuf\< \_CharT, \_Traits \>::imbue()***,* **std::basic\_filebuf\< \_CharT, \_Traits \>::overflow()***,* **std::basic\_filebuf\< \_CharT, \_Traits \>::pbackfail()***,* **std::basic\_filebuf\< \_CharT, \_Traits \>::seekoff()***,* **std::basic\_stringbuf\< \_CharT, \_Traits, \_Alloc \>::seekoff()***,* **std::basic\_istream\< \_CharT, \_Traits \>::tellg()***, and* **std::basic\_ostream\< \_CharT, \_Traits \>::tellp()***.*

### const fmtflags std::ios\_base::dec \[static\], \[inherited\]

*Converts integer input or generates integer output in decimal base.*

*Referenced by* **std::dec()***,* **std::philox\_engine\< uint\_fast32\_t, 32, 4, 10, 0xCD9E8D57, 0x9E3779B9, 0xD2511F53, 0xBB67AE85 \>::operator\<\<***, and* **std::philox\_engine\< uint\_fast32\_t, 32, 4, 10, 0xCD9E8D57, 0x9E3779B9, 0xD2511F53, 0xBB67AE85 \>::operator\>\>***.*

### const seekdir std::ios\_base::end \[static\], \[inherited\]

*Request a seek relative to the current end of the sequence.*

*Referenced by* **std::basic\_filebuf\< \_CharT, \_Traits \>::open()***, and* **std::basic\_stringbuf\< \_CharT, \_Traits, \_Alloc \>::seekoff()***.*

### const iostate std::ios\_base::eofbit \[static\], \[inherited\]

*Indicates that an input operation reached the end of an input sequence.*

*Referenced by* **std::num\_get\< \_CharT, \_InIter \>::do\_get()***,* **std::num\_get\< \_CharT, \_InIter \>::do\_get()***,* **std::num\_get\< \_CharT, \_InIter \>::do\_get()***,* **std::num\_get\< \_CharT, \_InIter \>::do\_get()***,* **std::time\_get\< \_CharT, \_InIter \>::do\_get()***,* **std::time\_get\< \_CharT, \_InIter \>::do\_get\_date()***,* **std::time\_get\< \_CharT, \_InIter \>::do\_get\_monthname()***,* **std::time\_get\< \_CharT, \_InIter \>::do\_get\_time()***,* **std::time\_get\< \_CharT, \_InIter \>::do\_get\_weekday()***,* **std::time\_get\< \_CharT, \_InIter \>::do\_get\_year()***,* **std::basic\_istream\< \_CharT, \_Traits \>::get()***,* **std::basic\_istream\< \_CharT, \_Traits \>::get()***,* **std::time\_get\< \_CharT, \_InIter \>::get()***,* **std::basic\_istream\< \_CharT, \_Traits \>::ignore()***,* **std::basic\_istream\< \_CharT, \_Traits \>::operator\>\>()***,* **std::operator\>\>()***,* **std::basic\_istream\< \_CharT, char\_traits\< \_CharT \> \>::peek()***,* **std::basic\_istream\< \_CharT, \_Traits \>::putback()***,* **std::basic\_istream\< \_CharT, \_Traits \>::read()***,* **std::basic\_istream\< \_CharT, \_Traits \>::readsome()***,* **std::basic\_istream\< \_CharT, \_Traits \>::seekg()***,* **std::basic\_istream\< \_CharT, \_Traits \>::seekg()***,* **std::basic\_istream\< \_CharT, char\_traits\< \_CharT \> \>::seekg()***,* **std::basic\_istream\< \_CharT, \_Traits \>::unget()***,* **std::basic\_istream\< \_CharT, char\_traits\< \_CharT \> \>::unget()***, and* **std::ws()***.*

### const iostate std::ios\_base::failbit \[static\], \[inherited\]

*Indicates that an input operation failed to read the expected characters, or that an output operation failed to generate the desired characters.*

*Referenced by* **std::basic\_ostream\< \_CharT, \_Traits \>::sentry::sentry()***,* **std::basic\_fstream\< char \>::close()***,* **std::basic\_ifstream\< char \>::close()***,* **std::basic\_ofstream\< char \>::close()***,* **std::num\_get\< \_CharT, \_InIter \>::do\_get()***,* **std::time\_get\< \_CharT, \_InIter \>::do\_get\_monthname()***,* **std::time\_get\< \_CharT, \_InIter \>::do\_get\_weekday()***,* **std::time\_get\< \_CharT, \_InIter \>::do\_get\_year()***,* **std::basic\_istream\< \_CharT, \_Traits \>::get()***,* **std::basic\_istream\< \_CharT, \_Traits \>::get()***,* **std::time\_get\< \_CharT, \_InIter \>::get()***,* **std::basic\_fstream\< char \>::open()***,* **std::basic\_fstream\< char \>::open()***,* **std::basic\_ifstream\< char \>::open()***,* **std::basic\_ifstream\< char \>::open()***,* **std::basic\_ofstream\< char \>::open()***,* **std::basic\_ofstream\< char \>::open()***,* **std::operator\<\<()***,* **std::basic\_iostream\< char\_type, traits\_type \>::operator\>\>()***,* **std::basic\_istream\< \_CharT, \_Traits \>::operator\>\>()***,* **std::basic\_istream\< \_CharT, \_Traits \>::operator\>\>()***,* **std::operator\>\>()***,* **std::basic\_istream\< \_CharT, \_Traits \>::read()***,* **std::basic\_istream\< \_CharT, \_Traits \>::seekg()***,* **std::basic\_istream\< \_CharT, \_Traits \>::seekg()***,* **std::basic\_ostream\< \_CharT, \_Traits \>::seekp()***, and* **std::basic\_ostream\< \_CharT, \_Traits \>::seekp()***.*

### const fmtflags std::ios\_base::fixed \[static\], \[inherited\]

*Generate floating-point output in fixed-point notation.*

*Referenced by* **std::fixed()***, and* **std::hexfloat()***.*

### const fmtflags std::ios\_base::floatfield \[static\], \[inherited\]

*A mask of scientific\|fixed. Useful for the 2-arg form of* setf*.*

*Referenced by* **std::defaultfloat()***,* **std::fixed()***,* **std::hexfloat()***, and* **std::scientific()***.*

### const iostate std::ios\_base::goodbit \[static\], \[inherited\]

*Indicates all is well.*

*Referenced by* **std::basic\_istream\< \_CharT, \_Traits \>::sentry::sentry()***,* **std::num\_get\< \_CharT, \_InIter \>::do\_get()***,* **std::time\_get\< \_CharT, \_InIter \>::do\_get()***,* **std::time\_get\< \_CharT, \_InIter \>::do\_get\_monthname()***,* **std::time\_get\< \_CharT, \_InIter \>::do\_get\_weekday()***,* **std::time\_get\< \_CharT, \_InIter \>::do\_get\_year()***,* **std::basic\_ostream\< \_CharT, \_Traits \>::flush()***,* **std::basic\_iostream\< char\_type, traits\_type \>::get()***,* **std::basic\_istream\< \_CharT, \_Traits \>::get()***,* **std::basic\_istream\< \_CharT, \_Traits \>::get()***,* **std::basic\_istream\< \_CharT, \_Traits \>::get()***,* **std::basic\_istream\< \_CharT, \_Traits \>::get()***,* **std::time\_get\< \_CharT, \_InIter \>::get()***,* **std::basic\_istream\< \_CharT, \_Traits \>::ignore()***,* **std::basic\_istream\< \_CharT, \_Traits \>::ignore()***,* **std::basic\_istream\< \_CharT, \_Traits \>::ignore()***,* **std::basic\_iostream\< char\_type, traits\_type \>::operator\<\<()***,* **std::basic\_ostream\< \_CharT, \_Traits \>::operator\<\<()***,* **std::basic\_iostream\< char\_type, traits\_type \>::operator\>\>()***,* **std::basic\_istream\< \_CharT, \_Traits \>::operator\>\>()***,* **std::basic\_istream\< \_CharT, \_Traits \>::operator\>\>()***,* **std::operator\>\>()***,* **std::basic\_istream\< \_CharT, \_Traits \>::peek()***,* **std::basic\_ostream\< \_CharT, \_Traits \>::put()***,* **std::basic\_istream\< \_CharT, \_Traits \>::putback()***,* **std::basic\_istream\< \_CharT, \_Traits \>::read()***,* **std::basic\_istream\< \_CharT, \_Traits \>::readsome()***,* **std::basic\_istream\< \_CharT, \_Traits \>::seekg()***,* **std::basic\_istream\< \_CharT, \_Traits \>::seekg()***,* **std::basic\_istream\< \_CharT, \_Traits \>::sync()***,* **std::basic\_istream\< \_CharT, \_Traits \>::unget()***, and* **std::ws()***.*

### const fmtflags std::ios\_base::hex \[static\], \[inherited\]

*Converts integer input or generates integer output in hexadecimal base.*

*Referenced by* **std::num\_get\< \_CharT, \_InIter \>::do\_get()***,* **std::num\_put\< \_CharT, \_OutIter \>::do\_put()***, and* **std::hex()***.*

### const openmode std::ios\_base::in \[static\], \[inherited\]

*Open for input. Default for* ifstream *and fstream.*

*Referenced by* **std::basic\_fstream\< char \>::basic\_fstream()***,* **std::basic\_fstream\< char \>::basic\_fstream()***,* **std::basic\_fstream\< char \>::basic\_fstream()***,* **std::basic\_ifstream\< char \>::basic\_ifstream()***,* **std::basic\_ifstream\< char \>::basic\_ifstream()***,* **std::basic\_ifstream\< char \>::basic\_ifstream()***,* **std::basic\_istringstream\< char \>::basic\_istringstream()***,* **std::basic\_stringbuf\< char \>::basic\_stringbuf()***,* **std::basic\_stringstream\< char \>::basic\_stringstream()***,* **std::basic\_filebuf\< char\_type, traits\_type \>::\_M\_set\_buffer()***,* **std::basic\_fstream\< char \>::open()***,* **std::basic\_fstream\< char \>::open()***,* **std::basic\_fstream\< char \>::open()***,* **std::basic\_ifstream\< char \>::open()***,* **std::basic\_ifstream\< char \>::open()***,* **std::basic\_ifstream\< char \>::open()***,* **std::basic\_stringbuf\< \_CharT, \_Traits, \_Alloc \>::overflow()***,* **std::basic\_filebuf\< \_CharT, \_Traits \>::pbackfail()***,* **std::basic\_streambuf\< char\_type, traits\_type \>::pubseekoff()***,* **std::basic\_streambuf\< char\_type, traits\_type \>::pubseekpos()***,* **std::basic\_istream\< \_CharT, \_Traits \>::seekg()***,* **std::basic\_istream\< \_CharT, \_Traits \>::seekg()***,* **std::basic\_streambuf\< char\_type, traits\_type \>::seekoff()***,* **std::basic\_stringbuf\< \_CharT, \_Traits, \_Alloc \>::seekoff()***,* **std::basic\_stringbuf\< char \>::seekoff()***,* **std::basic\_streambuf\< char\_type, traits\_type \>::seekpos()***,* **std::basic\_stringbuf\< \_CharT, \_Traits, \_Alloc \>::seekpos()***,* **std::basic\_stringbuf\< char \>::seekpos()***,* **std::basic\_filebuf\< \_CharT, \_Traits \>::showmanyc()***,* **std::basic\_stringbuf\< char \>::showmanyc()***,* **std::basic\_istream\< \_CharT, \_Traits \>::tellg()***,* **std::basic\_filebuf\< \_CharT, \_Traits \>::underflow()***,* **std::basic\_stringbuf\< \_CharT, \_Traits, \_Alloc \>::underflow()***, and* **std::basic\_filebuf\< \_CharT, \_Traits \>::xsgetn()***.*

### const fmtflags std::ios\_base::internal \[static\], \[inherited\]

*Adds fill characters at a designated internal point in certain generated output, or identical to* right *if no such point is designated.*

*Referenced by* **std::internal()***.*

### const fmtflags std::ios\_base::left \[static\], \[inherited\]

*Adds fill characters on the right (final positions) of certain generated output. (I.e., the thing you print is flush left.).*

*Referenced by* **std::num\_put\< \_CharT, \_OutIter \>::do\_put()***,* **std::left()***, and* **std::philox\_engine\< uint\_fast32\_t, 32, 4, 10, 0xCD9E8D57, 0x9E3779B9, 0xD2511F53, 0xBB67AE85 \>::operator\<\<***.*

### const fmtflags std::ios\_base::oct \[static\], \[inherited\]

*Converts integer input or generates integer output in octal base.*

*Referenced by* **std::oct()***.*

### const openmode std::ios\_base::out \[static\], \[inherited\]

*Open for output. Default for* ofstream *and fstream.*

*Referenced by* **std::basic\_fstream\< char \>::basic\_fstream()***,* **std::basic\_fstream\< char \>::basic\_fstream()***,* **std::basic\_fstream\< char \>::basic\_fstream()***,* **std::basic\_ofstream\< char \>::basic\_ofstream()***,* **std::basic\_ofstream\< char \>::basic\_ofstream()***,* **std::basic\_ofstream\< char \>::basic\_ofstream()***,* **std::basic\_ostringstream\< char \>::basic\_ostringstream()***,* **std::basic\_stringbuf\< char \>::basic\_stringbuf()***,* **std::basic\_stringstream\< char \>::basic\_stringstream()***,* **std::basic\_filebuf\< char\_type, traits\_type \>::\_M\_set\_buffer()***,* **std::basic\_fstream\< char \>::open()***,* **std::basic\_fstream\< char \>::open()***,* **std::basic\_fstream\< char \>::open()***,* **std::basic\_ofstream\< char \>::open()***,* **std::basic\_ofstream\< char \>::open()***,* **std::basic\_ofstream\< char \>::open()***,* **std::basic\_filebuf\< \_CharT, \_Traits \>::overflow()***,* **std::basic\_stringbuf\< \_CharT, \_Traits, \_Alloc \>::overflow()***,* **std::basic\_stringbuf\< \_CharT, \_Traits, \_Alloc \>::pbackfail()***,* **std::basic\_streambuf\< char\_type, traits\_type \>::pubseekoff()***,* **std::basic\_streambuf\< char\_type, traits\_type \>::pubseekpos()***,* **std::basic\_streambuf\< char\_type, traits\_type \>::seekoff()***,* **std::basic\_stringbuf\< \_CharT, \_Traits, \_Alloc \>::seekoff()***,* **std::basic\_stringbuf\< char \>::seekoff()***,* **std::basic\_ostream\< \_CharT, \_Traits \>::seekp()***,* **std::basic\_ostream\< \_CharT, \_Traits \>::seekp()***,* **std::basic\_streambuf\< char\_type, traits\_type \>::seekpos()***,* **std::basic\_stringbuf\< \_CharT, \_Traits, \_Alloc \>::seekpos()***,* **std::basic\_stringbuf\< char \>::seekpos()***,* **std::basic\_ostream\< \_CharT, \_Traits \>::tellp()***, and* **std::basic\_filebuf\< \_CharT, \_Traits \>::xsputn()***.*

### const fmtflags std::ios\_base::right \[static\], \[inherited\]

*Adds fill characters on the left (initial positions) of certain generated output. (I.e., the thing you print is flush right.).*

*Referenced by* **std::right()***.*

### const fmtflags std::ios\_base::scientific \[static\], \[inherited\]

*Generates floating-point output in scientific notation.*

*Referenced by* **std::hexfloat()***, and* **std::scientific()***.*

### const fmtflags std::ios\_base::showbase \[static\], \[inherited\]

*Generates a prefix indicating the numeric base of generated integer output.*

*Referenced by* **std::num\_put\< \_CharT, \_OutIter \>::do\_put()***,* **std::noshowbase()***, and* **std::showbase()***.*

### const fmtflags std::ios\_base::showpoint \[static\], \[inherited\]

*Generates a decimal-point character unconditionally in generated floating-point output.*

*Referenced by* **std::noshowpoint()***, and* **std::showpoint()***.*

### const fmtflags std::ios\_base::showpos \[static\], \[inherited\]

*Generates a + sign in non-negative generated numeric output.*

*Referenced by* **std::noshowpos()***, and* **std::showpos()***.*

### const fmtflags std::ios\_base::skipws \[static\], \[inherited\]

*Skips leading white space before certain input operations.*

*Referenced by* **std::noskipws()***,* **std::\_\_detail::operator\>\>()***,* **std::philox\_engine\< uint\_fast32\_t, 32, 4, 10, 0xCD9E8D57, 0x9E3779B9, 0xD2511F53, 0xBB67AE85 \>::operator\>\>***, and* **std::skipws()***.*

### const openmode std::ios\_base::trunc \[static\], \[inherited\]

*Truncate an existing stream when opening. Default for* ofstream*.*

### const fmtflags std::ios\_base::unitbuf \[static\], \[inherited\]

*Flushes output after each output operation.*

*Referenced by* **std::basic\_ostream\< \_CharT, \_Traits \>::sentry::~sentry()***,* **std::nounitbuf()***, and* **std::unitbuf()***.*

### const fmtflags std::ios\_base::uppercase \[static\], \[inherited\]

*Replaces certain lowercase letters with their uppercase equivalents in generated output.*

*Referenced by* **std::num\_put\< \_CharT, \_OutIter \>::do\_put()***,* **std::nouppercase()***, and* **std::uppercase()***.*

## Author

*Generated automatically by Doxygen for libstdc++ from the source code.*
