libstdc++
std::basic_ostream< _CharT, _Traits >::sentry Class Reference

#include <ostream.h>

Inheritance diagram for std::basic_ostream< _CharT, _Traits >::sentry:
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Public Types

typedef ctype< _CharT > __ctype_type
 
typedef basic_ios< _CharT, _Traits > __ios_type
 
typedef num_put< _CharT, ostreambuf_iterator< _CharT, _Traits > > __num_put_type
 
typedef basic_ostream< _CharT, _Traits > __ostream_type
 
typedef basic_streambuf< _CharT, _Traits > __streambuf_type
 
typedef _CharT char_type
 
enum  event
 
typedef void(* event_callback) (event __e, ios_base &__b, int __i)
 
typedef _Traits::int_type int_type
 
typedef _Ios_Iostate iostate
 
typedef _Traits::off_type off_type
 
typedef _Ios_Openmode openmode
 
typedef _Traits::pos_type pos_type
 
typedef _Ios_Seekdir seekdir
 
typedef _Traits traits_type
 
typedef num_get< _CharT, istreambuf_iterator< _CharT, _Traits > > __num_get_type
 

Public Member Functions

 sentry (basic_ostream< _CharT, _Traits > &__os)
 
virtual ~basic_ostream ()
 
 ~sentry ()
 
const locale_M_getloc () const
 
basic_ostream< _CharT, _Traits > & _M_insert (_ValueT __v)
 
basic_ostream< _CharT, _Traits > & _M_insert (_ValueT __v)
 
void _M_setstate (iostate __state)
 
bool bad () const
 
 basic_ostream (__streambuf_type *__sb)
 
void clear (iostate __state=goodbit)
 
basic_ioscopyfmt (const basic_ios &__rhs)
 
bool eof () const
 
iostate exceptions () const
 
void exceptions (iostate __except)
 
bool fail () const
 
char_type fill () const
 
char_type fill (char_type __ch)
 
fmtflags flags () const
 
fmtflags flags (fmtflags __fmtfl)
 
__ostream_typeflush ()
 
locale getloc () const
 
bool good () const
 
locale imbue (const locale &__loc)
 
long & iword (int __ix)
 
char narrow (char_type __c, char __dfault) const
 
 operator bool () const
 
__ostream_typeoperator<< (__streambuf_type *__sb)
 
__ostream_typeoperator<< (const void *__p)
 
__ostream_typeoperator<< (nullptr_t)
 
streamsize precision () const
 
streamsize precision (streamsize __prec)
 
void *& pword (int __ix)
 
basic_streambuf< _CharT, _Traits > * rdbuf () const
 
basic_streambuf< _CharT, _Traits > * rdbuf (basic_streambuf< _CharT, _Traits > *__sb)
 
iostate rdstate () const
 
void register_callback (event_callback __fn, int __index)
 
__ostream_typeseekp (off_type, ios_base::seekdir)
 
__ostream_typeseekp (pos_type)
 
fmtflags setf (fmtflags __fmtfl)
 
fmtflags setf (fmtflags __fmtfl, fmtflags __mask)
 
void setstate (iostate __state)
 
pos_type tellp ()
 
basic_ostream< _CharT, _Traits > * tie () const
 
basic_ostream< _CharT, _Traits > * tie (basic_ostream< _CharT, _Traits > *__tiestr)
 
void unsetf (fmtflags __mask)
 
char_type widen (char __c) const
 
streamsize width () const
 
streamsize width (streamsize __wide)
 
__ostream_typeoperator<< (__ostream_type &(*__pf)(__ostream_type &))
 
__ostream_typeoperator<< (__ios_type &(*__pf)(__ios_type &))
 
__ostream_typeoperator<< (ios_base &(*__pf)(ios_base &))
 
Inserters

All the operator<< functions (aka formatted output functions) have some common behavior. Each starts by constructing a temporary object of type std::basic_ostream::sentry. This can have several effects, concluding with the setting of a status flag; see the sentry documentation for more.

If the sentry status is good, the function tries to generate whatever data is appropriate for the type of the argument.

If an exception is thrown during insertion, ios_base::badbit will be turned on in the stream's error state without causing an ios_base::failure to be thrown. The original exception will then be rethrown.

__ostream_typeoperator<< (long __n)
 
__ostream_typeoperator<< (unsigned long __n)
 
__ostream_typeoperator<< (bool __n)
 
__ostream_typeoperator<< (short __n)
 
__ostream_typeoperator<< (unsigned short __n)
 
__ostream_typeoperator<< (int __n)
 
__ostream_typeoperator<< (unsigned int __n)
 
__ostream_typeoperator<< (long long __n)
 
__ostream_typeoperator<< (unsigned long long __n)
 
__ostream_typeoperator<< (double __f)
 
__ostream_typeoperator<< (float __f)
 
__ostream_typeoperator<< (long double __f)
 
Unformatted Output Functions

All the unformatted output functions have some common behavior. Each starts by constructing a temporary object of type std::basic_ostream::sentry. This has several effects, concluding with the setting of a status flag; see the sentry documentation for more.

If the sentry status is good, the function tries to generate whatever data is appropriate for the type of the argument.

If an exception is thrown during insertion, ios_base::badbit will be turned on in the stream's error state. If badbit is on in the stream's exceptions mask, the exception will be rethrown without completing its actions.

__ostream_typeput (char_type __c)
 
__ostream_typewrite (const char_type *__s, streamsize __n)
 
 operator bool () const
 
bool operator! () const
 

Static Public Member Functions

static bool sync_with_stdio (bool __sync=true)
 
static int xalloc () throw ()
 

Public Attributes

class __attribute((__abi_tag__("cxx11"))) failure typedef _Ios_Fmtflags fmtflags
 

Static Public Attributes

static const openmode __noreplace
 
static const fmtflags adjustfield
 
static const openmode app
 
static const openmode ate
 
static const iostate badbit
 
static const fmtflags basefield
 
static const seekdir beg
 
static const openmode binary
 
static const fmtflags boolalpha
 
static const seekdir cur
 
static const fmtflags dec
 
static const seekdir end
 
static const iostate eofbit
 
static const iostate failbit
 
static const fmtflags fixed
 
static const fmtflags floatfield
 
static const iostate goodbit
 
static const fmtflags hex
 
static const openmode in
 
static const fmtflags internal
 
static const fmtflags left
 
static const fmtflags oct
 
static const openmode out
 
static const fmtflags right
 
static const fmtflags scientific
 
static const fmtflags showbase
 
static const fmtflags showpoint
 
static const fmtflags showpos
 
static const fmtflags skipws
 
static const openmode trunc
 
static const fmtflags unitbuf
 
static const fmtflags uppercase
 

Protected Types

enum  
 

Protected Member Functions

void _M_cache_locale (const locale &__loc)
 
void _M_call_callbacks (event __ev) throw ()
 
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 ()
 
__ostream_type_M_insert (_ValueT __v)
 
void _M_move (ios_base &) noexcept
 
void _M_swap (ios_base &__rhs) noexcept
 
 basic_ostream ()
 
 basic_ostream (basic_iostream< _CharT, _Traits > &)
 
 basic_ostream (basic_ostream &&__rhs)
 
 basic_ostream (const basic_ostream &)=delete
 
void init (basic_streambuf< _CharT, _Traits > *__sb)
 
void move (basic_ios &&__rhs)
 
void move (basic_ios &__rhs)
 
basic_ostreamoperator= (basic_ostream &&__rhs)
 
basic_ostreamoperator= (const basic_ostream &)=delete
 
void set_rdbuf (basic_streambuf< _CharT, _Traits > *__sb)
 
void swap (basic_ios &__rhs) noexcept
 
void swap (basic_ostream &__rhs)
 

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_ostream< _CharT, _Traits >::sentry

Performs setup work for output streams.

Objects of this class are created before all of the standard inserters are run. It is responsible for exception-safe prefix and suffix operations.

Definition at line 541 of file ostream.h.

Member Typedef Documentation

◆ __ctype_type

typedef ctype<_CharT> std::basic_ostream< _CharT, _Traits >::__ctype_type

Definition at line 82 of file ostream.h.

◆ __ios_type

typedef basic_ios<_CharT, _Traits> std::basic_ostream< _CharT, _Traits >::__ios_type

Definition at line 78 of file ostream.h.

◆ __num_get_type

typedef num_get<_CharT, istreambuf_iterator<_CharT, _Traits> > std::basic_ios< _CharT, _Traits >::__num_get_type

These are non-standard types.

Definition at line 97 of file basic_ios.h.

◆ __num_put_type

typedef num_put<_CharT, ostreambuf_iterator<_CharT, _Traits> > std::basic_ostream< _CharT, _Traits >::__num_put_type

Definition at line 81 of file ostream.h.

◆ __ostream_type

typedef basic_ostream<_CharT, _Traits> std::basic_ostream< _CharT, _Traits >::__ostream_type

Definition at line 79 of file ostream.h.

◆ __streambuf_type

typedef basic_streambuf<_CharT, _Traits> std::basic_ostream< _CharT, _Traits >::__streambuf_type

Definition at line 77 of file ostream.h.

◆ char_type

typedef _CharT std::basic_ostream< _CharT, _Traits >::char_type

Definition at line 70 of file ostream.h.

◆ event_callback

typedef void(* std::ios_base::event_callback) (event __e, ios_base &__b, int __i)

The type of an event callback function.

Parameters
__eOne of the members of the event enum.
__bReference to the ios_base object.
__iThe 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().

Definition at line 573 of file ios_base.h.

◆ int_type

typedef _Traits::int_type std::basic_ostream< _CharT, _Traits >::int_type

Definition at line 71 of file ostream.h.

◆ iostate

typedef _Ios_Iostate std::ios_base::iostate

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

Definition at line 453 of file ios_base.h.

◆ off_type

typedef _Traits::off_type std::basic_ostream< _CharT, _Traits >::off_type

Definition at line 73 of file ostream.h.

◆ openmode

typedef _Ios_Openmode std::ios_base::openmode

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

Definition at line 484 of file ios_base.h.

◆ pos_type

typedef _Traits::pos_type std::basic_ostream< _CharT, _Traits >::pos_type

Definition at line 72 of file ostream.h.

◆ seekdir

typedef _Ios_Seekdir std::ios_base::seekdir

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.

Definition at line 523 of file ios_base.h.

◆ traits_type

typedef _Traits std::basic_ostream< _CharT, _Traits >::traits_type

Definition at line 74 of file ostream.h.

Member Enumeration Documentation

◆ anonymous enum

anonymous enum
protected

Definition at line 648 of file ios_base.h.

◆ event

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().

Definition at line 556 of file ios_base.h.

Constructor & Destructor Documentation

◆ sentry()

template<typename _CharT, typename _Traits>
std::basic_ostream< _CharT, _Traits >::sentry::sentry ( basic_ostream< _CharT, _Traits > & __os)
explicit

The constructor performs preparatory work.

Parameters
__osThe output stream to guard.

If the stream state is good (__os.good() is true), then if the stream is tied to another output stream, is.tie()->flush() is called to synchronize the output sequences.

If the stream state is still good, then the sentry state becomes true (okay).

Definition at line 50 of file ostream.tcc.

References std::basic_ios< _CharT, _Traits >::bad(), basic_ostream(), std::ios_base::failbit, std::basic_ios< _CharT, _Traits >::good(), std::basic_ios< _CharT, _Traits >::setstate(), and std::basic_ios< _CharT, _Traits >::tie().

◆ ~sentry()

template<typename _CharT, typename _Traits>
std::basic_ostream< _CharT, _Traits >::sentry::~sentry ( )
inline

Possibly flushes the stream.

If ios_base::unitbuf is set in os.flags(), and std::uncaught_exception() is true, the sentry destructor flushes the output stream.

Definition at line 571 of file ostream.h.

References std::ios_base::badbit, std::uncaught_exception(), and std::ios_base::unitbuf.

◆ ~basic_ostream()

virtual std::basic_ostream< _CharT, _Traits >::~basic_ostream ( )
inlinevirtual

Base destructor.

This does very little apart from providing a virtual base dtor.

Definition at line 101 of file ostream.h.

Member Function Documentation

◆ _M_cache_locale()

void std::basic_ios< _CharT, _Traits >::_M_cache_locale ( const locale & __loc)
protected

Definition at line 525 of file basic_ios.tcc.

◆ _M_getloc()

const locale & std::ios_base::_M_getloc ( ) const
inline

Locale access.

Returns
A reference to the current locale.

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

Definition at line 852 of file ios_base.h.

◆ _M_insert() [1/2]

basic_ostream< _CharT, _Traits > & std::basic_ostream< _CharT, _Traits >::_M_insert ( _ValueT __v)

Definition at line 67 of file ostream.tcc.

◆ _M_insert() [2/2]

basic_ostream< _CharT, _Traits > & std::basic_ostream< _CharT, _Traits >::_M_insert ( _ValueT __v)

Definition at line 67 of file ostream.tcc.

◆ _M_setstate()

void std::basic_ios< _CharT, _Traits >::_M_setstate ( iostate __state)
inline

Definition at line 173 of file basic_ios.h.

◆ bad()

bool std::basic_ios< _CharT, _Traits >::bad ( ) const
inlinenodiscard

Fast error checking.

Returns
True if the badbit is set.

Note that other iostate flags may also be set.

Definition at line 224 of file basic_ios.h.

◆ basic_ostream() [1/4]

std::basic_ostream< _CharT, _Traits >::basic_ostream ( )
inlineprotected

Definition at line 440 of file ostream.h.

◆ basic_ostream() [2/4]

std::basic_ostream< _CharT, _Traits >::basic_ostream ( __streambuf_type * __sb)
inlineexplicit

Base constructor.

This ctor is almost never called by the user directly, rather from derived classes' initialization lists, which pass a pointer to their own stream buffer.

Definition at line 92 of file ostream.h.

Referenced by sentry().

◆ basic_ostream() [3/4]

std::basic_ostream< _CharT, _Traits >::basic_ostream ( basic_iostream< _CharT, _Traits > & )
inlineprotected

Definition at line 445 of file ostream.h.

◆ basic_ostream() [4/4]

std::basic_ostream< _CharT, _Traits >::basic_ostream ( basic_ostream && __rhs)
inlineprotected

Definition at line 449 of file ostream.h.

◆ clear()

void std::basic_ios< _CharT, _Traits >::clear ( iostate __state = goodbit)

[Re]sets the error state.

Parameters
__stateThe 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.

Definition at line 157 of file basic_ios.tcc.

◆ copyfmt()

basic_ios< _CharT, _Traits > & std::basic_ios< _CharT, _Traits >::copyfmt ( const basic_ios & __rhs)

Copies fields of __rhs into this.

Parameters
__rhsThe 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().

Definition at line 377 of file basic_ios.tcc.

◆ eof()

bool std::basic_ios< _CharT, _Traits >::eof ( ) const
inlinenodiscard

Fast error checking.

Returns
True if the eofbit is set.

Note that other iostate flags may also be set.

Definition at line 201 of file basic_ios.h.

◆ exceptions() [1/2]

iostate std::basic_ios< _CharT, _Traits >::exceptions ( ) const
inlinenodiscard

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.

Definition at line 236 of file basic_ios.h.

◆ exceptions() [2/2]

void std::basic_ios< _CharT, _Traits >::exceptions ( iostate __except)
inline

Throwing exceptions on errors.

Parameters
__exceptThe 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::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);
}
basic_ifstream< char > ifstream
Class for char input file streams.
Definition iosfwd:166
terminate_handler set_terminate(terminate_handler) noexcept
Takes a new handler function as an argument, returns the old function.
void __verbose_terminate_handler()
A replacement for the standard terminate_handler which prints more information about the terminating ...
ostream cerr
Linked to standard error (unbuffered)
static const iostate badbit
Indicates a loss of integrity in an input or output sequence (such as an irrecoverable read error fro...
Definition ios_base.h:457

Definition at line 271 of file basic_ios.h.

◆ fail()

bool std::basic_ios< _CharT, _Traits >::fail ( ) const
inlinenodiscard

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.

Definition at line 213 of file basic_ios.h.

◆ fill() [1/2]

char_type std::basic_ios< _CharT, _Traits >::fill ( ) const
inlinenodiscard

Retrieves the empty character.

Returns
The current fill character.

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

Definition at line 387 of file basic_ios.h.

◆ fill() [2/2]

char_type std::basic_ios< _CharT, _Traits >::fill ( char_type __ch)
inline

Sets a new empty character.

Parameters
__chThe 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.

Definition at line 404 of file basic_ios.h.

◆ flags() [1/2]

fmtflags std::ios_base::flags ( ) const
inlinenodiscard

Access to format flags.

Returns
The format control flags for both input and output.

Definition at line 694 of file ios_base.h.

◆ flags() [2/2]

fmtflags std::ios_base::flags ( fmtflags __fmtfl)
inline

Setting new format flags all at once.

Parameters
__fmtflThe new flags to set.
Returns
The previous format control flags.

This function overwrites all the format flags with __fmtfl.

Definition at line 705 of file ios_base.h.

◆ flush()

basic_ostream< _CharT, _Traits > & std::basic_ostream< _CharT, _Traits >::flush ( )

Synchronizing the stream buffer.

Returns
*this

If rdbuf() is a null pointer, changes nothing.

Otherwise, calls rdbuf()->pubsync(), and if that returns -1, sets badbit.

Definition at line 404 of file ostream.tcc.

◆ getloc()

locale std::ios_base::getloc ( ) const
inlinenodiscard

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.

Definition at line 841 of file ios_base.h.

◆ good()

bool std::basic_ios< _CharT, _Traits >::good ( ) const
inlinenodiscard

Fast error checking.

Returns
True if no error flags are set.

A wrapper around rdstate.

Definition at line 190 of file basic_ios.h.

◆ imbue()

locale std::basic_ios< _CharT, _Traits >::imbue ( const locale & __loc)

Moves to a new locale.

Parameters
__locThe 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

Definition at line 425 of file basic_ios.tcc.

◆ init()

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.

Definition at line 487 of file basic_ios.tcc.

◆ iword()

long & std::ios_base::iword ( int __ix)
inline

Access to integer array.

Parameters
__ixIndex 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.

Definition at line 887 of file ios_base.h.

◆ move() [1/2]

void std::basic_ios< _CharT, _Traits >::move ( basic_ios && __rhs)
inlineprotected

Definition at line 505 of file basic_ios.h.

◆ move() [2/2]

void std::basic_ios< _CharT, _Traits >::move ( basic_ios & __rhs)
inlineprotected

Definition at line 494 of file basic_ios.h.

◆ narrow()

char std::basic_ios< _CharT, _Traits >::narrow ( char_type __c,
char __dfault ) const
inline

Squeezes characters.

Parameters
__cThe character to narrow.
__dfaultThe character to narrow.
Returns
The narrowed character.

Maps a character of char_type to a character of char, if possible.

Returns the result of

const _Facet & use_facet(const locale &__loc)
Return a facet.
char narrow(char_type __c, char __dfault) const
Definition basic_ios.h:445
locale getloc() const
Definition ios_base.h:841

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

Definition at line 445 of file basic_ios.h.

◆ operator bool() [1/2]

std::basic_ios< _CharT, _Traits >::operator bool ( ) const
inlineexplicitnodiscard

The quick-and-easy status check.

This allows you to write constructs such as if (!a_stream) ... and while (a_stream) ...

Definition at line 124 of file basic_ios.h.

◆ operator bool() [2/2]

template<typename _CharT, typename _Traits>
std::basic_ostream< _CharT, _Traits >::sentry::operator bool ( ) const
inlineexplicit

Quick status checking.

Returns
The sentry state.

For ease of use, sentries may be converted to booleans. The return value is that of the sentry state (true == okay).

Definition at line 604 of file ostream.h.

◆ operator!()

bool std::basic_ios< _CharT, _Traits >::operator! ( ) const
inlinenodiscard

The quick-and-easy status check.

This allows you to write constructs such as if (!a_stream) ... and while (a_stream) ...

Definition at line 133 of file basic_ios.h.

◆ operator<<() [1/18]

__ostream_type & std::basic_ostream< _CharT, _Traits >::operator<< ( __ios_type &(* __pf )(__ios_type &))
inline

Interface for manipulators.

Manipulators such as std::endl and std::hex use these functions in constructs like "std::cout << std::endl". For more information, see the iomanip header.

Definition at line 124 of file ostream.h.

◆ operator<<() [2/18]

__ostream_type & std::basic_ostream< _CharT, _Traits >::operator<< ( __ostream_type &(* __pf )(__ostream_type &))
inline

Interface for manipulators.

Manipulators such as std::endl and std::hex use these functions in constructs like "std::cout << std::endl". For more information, see the iomanip header.

Definition at line 115 of file ostream.h.

◆ operator<<() [3/18]

basic_ostream< _CharT, _Traits > & std::basic_ostream< _CharT, _Traits >::operator<< ( __streambuf_type * __sb)

Extracting from another streambuf.

Parameters
__sbA pointer to a streambuf

This function behaves like one of the basic arithmetic extractors, in that it also constructs a sentry object and has the same error handling behavior.

If __sb is NULL, the stream will set failbit in its error state.

Characters are extracted from __sb and inserted into *this until one of the following occurs:

  • the input stream reaches end-of-file,
  • insertion into the output sequence fails (in this case, the character that would have been inserted is not extracted), or
  • an exception occurs while getting a character from __sb, which sets failbit in the error state

If the function inserts no characters, failbit is set.

Definition at line 338 of file ostream.tcc.

◆ operator<<() [4/18]

__ostream_type & std::basic_ostream< _CharT, _Traits >::operator<< ( bool __n)
inline

Integer arithmetic inserters.

Parameters
__nA variable of builtin integral type.
Returns
*this if successful

These functions use the stream's current locale (specifically, the num_get facet) to perform numeric formatting.

Definition at line 181 of file ostream.h.

◆ operator<<() [5/18]

__ostream_type & std::basic_ostream< _CharT, _Traits >::operator<< ( const void * __p)
inline

Pointer arithmetic inserters.

Parameters
__pA variable of pointer type.
Returns
*this if successful

These functions use the stream's current locale (specifically, the num_get facet) to perform numeric formatting.

Definition at line 300 of file ostream.h.

◆ operator<<() [6/18]

__ostream_type & std::basic_ostream< _CharT, _Traits >::operator<< ( double __f)
inline

Floating point arithmetic inserters.

Parameters
__fA variable of builtin floating point type.
Returns
*this if successful

These functions use the stream's current locale (specifically, the num_get facet) to perform numeric formatting.

Definition at line 230 of file ostream.h.

◆ operator<<() [7/18]

__ostream_type & std::basic_ostream< _CharT, _Traits >::operator<< ( float __f)
inline

Floating point arithmetic inserters.

Parameters
__fA variable of builtin floating point type.
Returns
*this if successful

These functions use the stream's current locale (specifically, the num_get facet) to perform numeric formatting.

Definition at line 234 of file ostream.h.

◆ operator<<() [8/18]

basic_ostream< _CharT, _Traits > & std::basic_ostream< _CharT, _Traits >::operator<< ( int __n)

Integer arithmetic inserters.

Parameters
__nA variable of builtin integral type.
Returns
*this if successful

These functions use the stream's current locale (specifically, the num_get facet) to perform numeric formatting.

Definition at line 196 of file ostream.tcc.

◆ operator<<() [9/18]

__ostream_type & std::basic_ostream< _CharT, _Traits >::operator<< ( ios_base &(* __pf )(ios_base &))
inline

Interface for manipulators.

Manipulators such as std::endl and std::hex use these functions in constructs like "std::cout << std::endl". For more information, see the iomanip header.

Definition at line 134 of file ostream.h.

◆ operator<<() [10/18]

__ostream_type & std::basic_ostream< _CharT, _Traits >::operator<< ( long __n)
inline

Integer arithmetic inserters.

Parameters
__nA variable of builtin integral type.
Returns
*this if successful

These functions use the stream's current locale (specifically, the num_get facet) to perform numeric formatting.

Definition at line 173 of file ostream.h.

◆ operator<<() [11/18]

__ostream_type & std::basic_ostream< _CharT, _Traits >::operator<< ( long double __f)
inline

Floating point arithmetic inserters.

Parameters
__fA variable of builtin floating point type.
Returns
*this if successful

These functions use the stream's current locale (specifically, the num_get facet) to perform numeric formatting.

Definition at line 242 of file ostream.h.

◆ operator<<() [12/18]

__ostream_type & std::basic_ostream< _CharT, _Traits >::operator<< ( long long __n)
inline

Integer arithmetic inserters.

Parameters
__nA variable of builtin integral type.
Returns
*this if successful

These functions use the stream's current locale (specifically, the num_get facet) to perform numeric formatting.

Definition at line 210 of file ostream.h.

◆ operator<<() [13/18]

__ostream_type & std::basic_ostream< _CharT, _Traits >::operator<< ( nullptr_t )
inline

Definition at line 305 of file ostream.h.

◆ operator<<() [14/18]

basic_ostream< _CharT, _Traits > & std::basic_ostream< _CharT, _Traits >::operator<< ( short __n)

Integer arithmetic inserters.

Parameters
__nA variable of builtin integral type.
Returns
*this if successful

These functions use the stream's current locale (specifically, the num_get facet) to perform numeric formatting.

Definition at line 185 of file ostream.tcc.

◆ operator<<() [15/18]

__ostream_type & std::basic_ostream< _CharT, _Traits >::operator<< ( unsigned int __n)
inline

Integer arithmetic inserters.

Parameters
__nA variable of builtin integral type.
Returns
*this if successful

These functions use the stream's current locale (specifically, the num_get facet) to perform numeric formatting.

Definition at line 199 of file ostream.h.

◆ operator<<() [16/18]

__ostream_type & std::basic_ostream< _CharT, _Traits >::operator<< ( unsigned long __n)
inline

Integer arithmetic inserters.

Parameters
__nA variable of builtin integral type.
Returns
*this if successful

These functions use the stream's current locale (specifically, the num_get facet) to perform numeric formatting.

Definition at line 177 of file ostream.h.

◆ operator<<() [17/18]

__ostream_type & std::basic_ostream< _CharT, _Traits >::operator<< ( unsigned long long __n)
inline

Integer arithmetic inserters.

Parameters
__nA variable of builtin integral type.
Returns
*this if successful

These functions use the stream's current locale (specifically, the num_get facet) to perform numeric formatting.

Definition at line 214 of file ostream.h.

◆ operator<<() [18/18]

__ostream_type & std::basic_ostream< _CharT, _Traits >::operator<< ( unsigned short __n)
inline

Integer arithmetic inserters.

Parameters
__nA variable of builtin integral type.
Returns
*this if successful

These functions use the stream's current locale (specifically, the num_get facet) to perform numeric formatting.

Definition at line 188 of file ostream.h.

◆ operator=()

basic_ostream & std::basic_ostream< _CharT, _Traits >::operator= ( basic_ostream && __rhs)
inlineprotected

Definition at line 458 of file ostream.h.

◆ precision() [1/2]

streamsize std::ios_base::precision ( ) const
inlinenodiscard

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.

Definition at line 765 of file ios_base.h.

◆ precision() [2/2]

streamsize std::ios_base::precision ( streamsize __prec)
inline

Changing flags.

Parameters
__precThe new precision value.
Returns
The previous value of precision().

Definition at line 774 of file ios_base.h.

◆ put()

basic_ostream< _CharT, _Traits > & std::basic_ostream< _CharT, _Traits >::put ( char_type __c)

Simple insertion.

Parameters
__cThe character to insert.
Returns
*this

Tries to insert __c.

Note
This function is not overloaded on signed char and unsigned char.

Definition at line 372 of file ostream.tcc.

◆ pword()

void *& std::ios_base::pword ( int __ix)
inline

Access to void pointer array.

Parameters
__ixIndex 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.

Definition at line 908 of file ios_base.h.

◆ rdbuf() [1/2]

basic_streambuf< _CharT, _Traits > * std::basic_ios< _CharT, _Traits >::rdbuf ( ) const
inlinenodiscard

Accessing the underlying buffer.

Returns
The current stream buffer.

This does not change the state of the stream.

Definition at line 337 of file basic_ios.h.

◆ rdbuf() [2/2]

basic_streambuf< _CharT, _Traits > * std::basic_ios< _CharT, _Traits >::rdbuf ( basic_streambuf< _CharT, _Traits > * __sb)

Changing the underlying buffer.

Parameters
__sbThe 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>
basic_streambuf< char > streambuf
Base class for char buffers.
Definition iosfwd:139
basic_fstream< char > fstream
Class for char mixed input and output file streams.
Definition iosfwd:172

Definition at line 363 of file basic_ios.tcc.

◆ rdstate()

iostate std::basic_ios< _CharT, _Traits >::rdstate ( ) const
inlinenodiscard

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().

Definition at line 146 of file basic_ios.h.

◆ register_callback()

void std::ios_base::register_callback ( event_callback __fn,
int __index )

Add the callback __fn with parameter __index.

Parameters
__fnThe function to add.
__indexThe 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.

◆ seekp() [1/2]

basic_ostream< _CharT, _Traits > & std::basic_ostream< _CharT, _Traits >::seekp ( off_type __off,
ios_base::seekdir __dir )

Changing the current write position.

Parameters
__offA file offset object.
__dirThe direction in which to seek.
Returns
*this

If fail() is not true, calls rdbuf()->pubseekoff(off,dir). If that function fails, sets failbit.

Definition at line 437 of file ostream.tcc.

◆ seekp() [2/2]

basic_ostream< _CharT, _Traits > & std::basic_ostream< _CharT, _Traits >::seekp ( pos_type __pos)

Changing the current write position.

Parameters
__posA file position object.
Returns
*this

If fail() is not true, calls rdbuf()->pubseekpos(pos). If that function fails, sets failbit.

Definition at line 425 of file ostream.tcc.

◆ set_rdbuf()

void std::basic_ios< _CharT, _Traits >::set_rdbuf ( basic_streambuf< _CharT, _Traits > * __sb)
inlineprotected

Definition at line 520 of file basic_ios.h.

◆ setf() [1/2]

fmtflags std::ios_base::setf ( fmtflags __fmtfl)
inline

Setting new format flags.

Parameters
__fmtflAdditional flags to set.
Returns
The previous format control flags.

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

Definition at line 721 of file ios_base.h.

◆ setf() [2/2]

fmtflags std::ios_base::setf ( fmtflags __fmtfl,
fmtflags __mask )
inline

Setting new format flags.

Parameters
__fmtflAdditional flags to set.
__maskThe 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.

Definition at line 738 of file ios_base.h.

◆ setstate()

void std::basic_ios< _CharT, _Traits >::setstate ( iostate __state)
inline

Sets additional flags in the error state.

Parameters
__stateThe additional state flag(s) to set.

See std::ios_base::iostate for the possible bit values.

Definition at line 166 of file basic_ios.h.

◆ swap() [1/2]

void std::basic_ios< _CharT, _Traits >::swap ( basic_ios & __rhs)
inlineprotectednoexcept

Definition at line 509 of file basic_ios.h.

◆ swap() [2/2]

void std::basic_ostream< _CharT, _Traits >::swap ( basic_ostream & __rhs)
inlineprotected

Definition at line 465 of file ostream.h.

◆ sync_with_stdio()

static bool std::ios_base::sync_with_stdio ( bool __sync = true)
static

Interaction with the standard C I/O objects.

Parameters
__syncWhether 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

◆ tellp()

basic_ostream< _CharT, _Traits >::pos_type std::basic_ostream< _CharT, _Traits >::tellp ( )

Getting the current write position.

Returns
A file position object.

If fail() is not false, returns pos_type(-1) to indicate failure. Otherwise returns rdbuf()->pubseekoff(0,cur,out).

Definition at line 414 of file ostream.tcc.

◆ tie() [1/2]

basic_ostream< _CharT, _Traits > * std::basic_ios< _CharT, _Traits >::tie ( ) const
inlinenodiscard

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.

Definition at line 310 of file basic_ios.h.

◆ tie() [2/2]

basic_ostream< _CharT, _Traits > * std::basic_ios< _CharT, _Traits >::tie ( basic_ostream< _CharT, _Traits > * __tiestr)
inline

Ties this stream to an output stream.

Parameters
__tiestrThe 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.

Definition at line 322 of file basic_ios.h.

◆ unsetf()

void std::ios_base::unsetf ( fmtflags __mask)
inline

Clearing format flags.

Parameters
__maskThe flags to unset.

This function clears __mask in the format flags.

Definition at line 753 of file ios_base.h.

◆ widen()

char_type std::basic_ios< _CharT, _Traits >::widen ( char __c) const
inline

Widens characters.

Parameters
__cThe character to widen.
Returns
The widened character.

Maps a character of char to a character of char_type.

Returns the result of

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

Definition at line 464 of file basic_ios.h.

◆ width() [1/2]

streamsize std::ios_base::width ( ) const
inlinenodiscard

Flags access.

Returns
The minimum field width to generate on output operations.

Minimum field width refers to the number of characters.

Definition at line 789 of file ios_base.h.

◆ width() [2/2]

streamsize std::ios_base::width ( streamsize __wide)
inline

Changing flags.

Parameters
__wideThe new width value.
Returns
The previous value of width().

Definition at line 798 of file ios_base.h.

◆ write()

basic_ostream< _CharT, _Traits > & std::basic_ostream< _CharT, _Traits >::write ( const char_type * __s,
streamsize __n )

Character string insertion.

Parameters
__sThe array to insert.
__nMaximum number of characters to insert.
Returns
*this

Characters are copied from __s and inserted into the stream until one of the following happens:

  • __n characters are inserted
  • inserting into the output sequence fails (in this case, badbit will be set in the stream's error state)
Note
This function is not overloaded on signed char and unsigned char.

Definition at line 391 of file ostream.tcc.

◆ xalloc()

static int std::ios_base::xalloc ( )
throw ( )
static

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.

Friends And Related Symbol Documentation

◆ sentry

friend class sentry
friend

Definition at line 105 of file ostream.h.

Member Data Documentation

◆ __noreplace

const openmode std::ios_base::__noreplace
static

Definition at line 506 of file ios_base.h.

◆ _M_callbacks

_Callback_list* std::ios_base::_M_callbacks
protected

Definition at line 627 of file ios_base.h.

◆ _M_ctype

const __ctype_type* std::basic_ios< _CharT, _Traits >::_M_ctype
protected

Definition at line 108 of file basic_ios.h.

◆ _M_exception

iostate std::ios_base::_M_exception
protected

Definition at line 592 of file ios_base.h.

◆ _M_fill

char_type std::basic_ios< _CharT, _Traits >::_M_fill
mutableprotected

Definition at line 103 of file basic_ios.h.

◆ _M_fill_init

bool std::basic_ios< _CharT, _Traits >::_M_fill_init
mutableprotected

Definition at line 104 of file basic_ios.h.

◆ _M_flags

fmtflags std::ios_base::_M_flags
protected

Definition at line 591 of file ios_base.h.

◆ _M_ios_locale

locale std::ios_base::_M_ios_locale
protected

Definition at line 659 of file ios_base.h.

◆ _M_local_word

_Words std::ios_base::_M_local_word[_S_local_word_size]
protected

Definition at line 649 of file ios_base.h.

◆ _M_num_get

const __num_get_type* std::basic_ios< _CharT, _Traits >::_M_num_get
protected

Definition at line 112 of file basic_ios.h.

◆ _M_num_put

const __num_put_type* std::basic_ios< _CharT, _Traits >::_M_num_put
protected

Definition at line 110 of file basic_ios.h.

◆ _M_precision

streamsize std::ios_base::_M_precision
protected

Definition at line 589 of file ios_base.h.

◆ _M_streambuf

basic_streambuf<_CharT, _Traits>* std::basic_ios< _CharT, _Traits >::_M_streambuf
protected

Definition at line 105 of file basic_ios.h.

◆ _M_streambuf_state

iostate std::ios_base::_M_streambuf_state
protected

Definition at line 593 of file ios_base.h.

◆ _M_tie

basic_ostream<_CharT, _Traits>* std::basic_ios< _CharT, _Traits >::_M_tie
protected

Definition at line 102 of file basic_ios.h.

◆ _M_width

streamsize std::ios_base::_M_width
protected

Definition at line 590 of file ios_base.h.

◆ _M_word

_Words* std::ios_base::_M_word
protected

Definition at line 653 of file ios_base.h.

◆ _M_word_size

int std::ios_base::_M_word_size
protected

Definition at line 652 of file ios_base.h.

◆ _M_word_zero

_Words std::ios_base::_M_word_zero
protected

Definition at line 644 of file ios_base.h.

◆ adjustfield

const fmtflags std::ios_base::adjustfield
static

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

Definition at line 433 of file ios_base.h.

◆ app

const openmode std::ios_base::app
static

Seek to end before each write.

Definition at line 487 of file ios_base.h.

◆ ate

const openmode std::ios_base::ate
static

Open and seek to end immediately after opening.

Definition at line 490 of file ios_base.h.

◆ badbit

const iostate std::ios_base::badbit
static

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

Definition at line 457 of file ios_base.h.

◆ basefield

const fmtflags std::ios_base::basefield
static

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

Definition at line 436 of file ios_base.h.

◆ beg

const seekdir std::ios_base::beg
static

Request a seek relative to the beginning of the stream.

Definition at line 526 of file ios_base.h.

◆ binary

const openmode std::ios_base::binary
static

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.

Definition at line 495 of file ios_base.h.

◆ boolalpha

const fmtflags std::ios_base::boolalpha
static

Insert/extract bool in alphabetic rather than numeric format.

Definition at line 381 of file ios_base.h.

◆ cur

const seekdir std::ios_base::cur
static

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

Definition at line 529 of file ios_base.h.

◆ dec

const fmtflags std::ios_base::dec
static

Converts integer input or generates integer output in decimal base.

Definition at line 384 of file ios_base.h.

◆ end

const seekdir std::ios_base::end
static

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

Definition at line 532 of file ios_base.h.

◆ eofbit

const iostate std::ios_base::eofbit
static

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

Definition at line 460 of file ios_base.h.

◆ failbit

const iostate std::ios_base::failbit
static

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

Definition at line 465 of file ios_base.h.

◆ fixed

const fmtflags std::ios_base::fixed
static

Generate floating-point output in fixed-point notation.

Definition at line 387 of file ios_base.h.

◆ floatfield

const fmtflags std::ios_base::floatfield
static

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

Definition at line 439 of file ios_base.h.

◆ fmtflags

class __attribute ((__abi_tag__ ("cxx11"))) failure typedef _Ios_Fmtflags std::ios_base::fmtflags

These are thrown to indicate problems with io.

27.4.2.1.1 Class ios_base::failure

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

Definition at line 378 of file ios_base.h.

◆ goodbit

const iostate std::ios_base::goodbit
static

Indicates all is well.

Definition at line 468 of file ios_base.h.

◆ hex

const fmtflags std::ios_base::hex
static

Converts integer input or generates integer output in hexadecimal base.

Definition at line 390 of file ios_base.h.

◆ in

const openmode std::ios_base::in
static

Open for input. Default for ifstream and fstream.

Definition at line 498 of file ios_base.h.

◆ internal

const fmtflags std::ios_base::internal
static

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

Definition at line 395 of file ios_base.h.

◆ left

const fmtflags std::ios_base::left
static

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

Definition at line 399 of file ios_base.h.

◆ oct

const fmtflags std::ios_base::oct
static

Converts integer input or generates integer output in octal base.

Definition at line 402 of file ios_base.h.

◆ out

const openmode std::ios_base::out
static

Open for output. Default for ofstream and fstream.

Definition at line 501 of file ios_base.h.

◆ right

const fmtflags std::ios_base::right
static

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

Definition at line 406 of file ios_base.h.

◆ scientific

const fmtflags std::ios_base::scientific
static

Generates floating-point output in scientific notation.

Definition at line 409 of file ios_base.h.

◆ showbase

const fmtflags std::ios_base::showbase
static

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

Definition at line 413 of file ios_base.h.

◆ showpoint

const fmtflags std::ios_base::showpoint
static

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

Definition at line 417 of file ios_base.h.

◆ showpos

const fmtflags std::ios_base::showpos
static

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

Definition at line 420 of file ios_base.h.

◆ skipws

const fmtflags std::ios_base::skipws
static

Skips leading white space before certain input operations.

Definition at line 423 of file ios_base.h.

◆ trunc

const openmode std::ios_base::trunc
static

Truncate an existing stream when opening. Default for ofstream.

Definition at line 504 of file ios_base.h.

◆ unitbuf

const fmtflags std::ios_base::unitbuf
static

Flushes output after each output operation.

Definition at line 426 of file ios_base.h.

◆ uppercase

const fmtflags std::ios_base::uppercase
static

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

Definition at line 430 of file ios_base.h.


The documentation for this class was generated from the following files: