libstdc++
std::basic_ifstream< _CharT, _Traits > Class Template Reference
Inheritance diagram for std::basic_ifstream< _CharT, _Traits >:
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Public Types

typedef ctype< _CharT > __ctype_type
 
typedef basic_filebuf< char_type, traits_type > __filebuf_type
 
typedef basic_ios< _CharT, _Traits > __ios_type
 
typedef basic_istream< char_type, traits_type > __istream_type
 
typedef num_get< _CharT, istreambuf_iterator< _CharT, _Traits > > __num_get_type
 
typedef basic_streambuf< _CharT, _Traits > __streambuf_type
 
typedef _CharT char_type
 
enum  event { erase_event , imbue_event , copyfmt_event }
 
typedef void(* event_callback) (event __e, ios_base &__b, int __i)
 
typedef _Ios_Fmtflags fmtflags
 
typedef traits_type::int_type int_type
 
typedef _Ios_Iostate iostate
 
typedef traits_type::off_type off_type
 
typedef _Ios_Openmode openmode
 
typedef traits_type::pos_type pos_type
 
typedef _Ios_Seekdir seekdir
 
typedef _Traits traits_type
 
typedef num_put< _CharT, ostreambuf_iterator< _CharT, _Traits > > __num_put_type
 

Public Member Functions

 basic_ifstream ()
 
 basic_ifstream (basic_ifstream &&__rhs)
 
template<typename _Path , typename _Require = _If_fs_path<_Path>>
 basic_ifstream (const _Path &__s, ios_base::openmode __mode=ios_base::in)
 
 basic_ifstream (const basic_ifstream &)=delete
 
 basic_ifstream (const char *__s, ios_base::openmode __mode=ios_base::in)
 
 basic_ifstream (const std::string &__s, ios_base::openmode __mode=ios_base::in)
 
 ~basic_ifstream ()
 
template<typename _ValueT >
basic_istream< _CharT, _Traits > & _M_extract (_ValueT &__v)
 
const locale_M_getloc () const
 
void _M_setstate (iostate __state)
 
bool bad () const
 
void clear (iostate __state=goodbit)
 
void close ()
 
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)
 
streamsize gcount () const
 
basic_istream< char > & getline (char_type *__s, streamsize __n, char_type __delim)
 
basic_istream< wchar_t > & getline (char_type *__s, streamsize __n, char_type __delim)
 
locale getloc () const
 
bool good () const
 
basic_istream< char > & ignore (streamsize __n)
 
basic_istream< wchar_t > & ignore (streamsize __n)
 
basic_istream< char > & ignore (streamsize __n, int_type __delim)
 
basic_istream< wchar_t > & ignore (streamsize __n, int_type __delim)
 
locale imbue (const locale &__loc)
 
bool is_open ()
 
bool is_open () const
 
long & iword (int __ix)
 
char narrow (char_type __c, char __dfault) const
 
template<typename _Path >
_If_fs_path< _Path, void > open (const _Path &__s, ios_base::openmode __mode=ios_base::in)
 
void open (const char *__s, ios_base::openmode __mode=ios_base::in)
 
void open (const std::string &__s, ios_base::openmode __mode=ios_base::in)
 
basic_ifstreamoperator= (basic_ifstream &&__rhs)
 
basic_ifstreamoperator= (const basic_ifstream &)=delete
 
__istream_typeoperator>> (__streambuf_type *__sb)
 
__istream_typeoperator>> (void *&__p)
 
streamsize precision () const
 
streamsize precision (streamsize __prec)
 
void *& pword (int __ix)
 
__filebuf_typerdbuf () const
 
basic_streambuf< _CharT, _Traits > * rdbuf (basic_streambuf< _CharT, _Traits > *__sb)
 
iostate rdstate () const
 
void register_callback (event_callback __fn, int __index)
 
fmtflags setf (fmtflags __fmtfl)
 
fmtflags setf (fmtflags __fmtfl, fmtflags __mask)
 
void setstate (iostate __state)
 
void swap (basic_ifstream &__rhs)
 
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)
 
__istream_typeoperator>> (__istream_type &(*__pf)(__istream_type &))
 
__istream_typeoperator>> (__ios_type &(*__pf)(__ios_type &))
 
__istream_typeoperator>> (ios_base &(*__pf)(ios_base &))
 
Extractors

All the operator>> functions (aka formatted input functions) have some common behavior. Each starts by constructing a temporary object of type std::basic_istream::sentry with the second argument (noskipws) set to false. 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 extract whatever data is appropriate for the type of the argument.

If an exception is thrown during extraction, ios_base::badbit will be turned on in the stream's error state (without causing an ios_base::failure to be thrown) and the original exception will be rethrown if badbit is set in the exceptions mask.

__istream_typeoperator>> (bool &__n)
 
__istream_typeoperator>> (short &__n)
 
__istream_typeoperator>> (unsigned short &__n)
 
__istream_typeoperator>> (int &__n)
 
__istream_typeoperator>> (unsigned int &__n)
 
__istream_typeoperator>> (long &__n)
 
__istream_typeoperator>> (unsigned long &__n)
 
__istream_typeoperator>> (long long &__n)
 
__istream_typeoperator>> (unsigned long long &__n)
 
__istream_typeoperator>> (float &__f)
 
__istream_typeoperator>> (double &__f)
 
__istream_typeoperator>> (long double &__f)
 
Unformatted Input Functions

All the unformatted input functions have some common behavior. Each starts by constructing a temporary object of type std::basic_istream::sentry with the second argument (noskipws) set to true. 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 extract whatever data is appropriate for the type of the argument.

The number of characters extracted is stored for later retrieval by gcount().

If an exception is thrown during extraction, ios_base::badbit will be turned on in the stream's error state (without causing an ios_base::failure to be thrown) and the original exception will be rethrown if badbit is set in the exceptions mask.

int_type get ()
 
__istream_typeget (char_type &__c)
 
__istream_typeget (char_type *__s, streamsize __n, char_type __delim)
 
__istream_typeget (char_type *__s, streamsize __n)
 
__istream_typeget (__streambuf_type &__sb, char_type __delim)
 
__istream_typeget (__streambuf_type &__sb)
 
__istream_typegetline (char_type *__s, streamsize __n, char_type __delim)
 
__istream_typegetline (char_type *__s, streamsize __n)
 
__istream_typeignore (streamsize __n, int_type __delim)
 
__istream_typeignore (streamsize __n)
 
__istream_typeignore ()
 
int_type peek ()
 
__istream_typeread (char_type *__s, streamsize __n)
 
streamsize readsome (char_type *__s, streamsize __n)
 
__istream_typeputback (char_type __c)
 
__istream_typeunget ()
 
int sync ()
 
pos_type tellg ()
 
__istream_typeseekg (pos_type)
 
__istream_typeseekg (off_type, ios_base::seekdir)
 
 operator bool () const
 
bool operator! () const
 

Static Public Member Functions

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

Static Public Attributes

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  { _S_local_word_size }
 

Protected Member Functions

void _M_cache_locale (const locale &__loc)
 
void _M_call_callbacks (event __ev) throw ()
 
void _M_dispose_callbacks (void) throw ()
 
template<typename _ValueT >
__istream_type_M_extract (_ValueT &__v)
 
_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)
 
void move (basic_ios &&__rhs)
 
void move (basic_ios &__rhs)
 
void set_rdbuf (basic_streambuf< _CharT, _Traits > *__sb)
 
void swap (basic_ios &__rhs) noexcept
 
void swap (basic_istream &__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
 
streamsize _M_gcount
 
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_ifstream< _CharT, _Traits >

Controlling input for files.

Template Parameters
_CharTType of character stream.
_TraitsTraits for character type, defaults to char_traits<_CharT>.

This class supports reading from named files, using the inherited functions from std::basic_istream. To control the associated sequence, an instance of std::basic_filebuf is used, which this page refers to as sb.

Definition at line 497 of file fstream.

Member Typedef Documentation

◆ __num_put_type

template<typename _CharT , typename _Traits >
typedef num_put<_CharT, ostreambuf_iterator<_CharT, _Traits> > std::basic_ios< _CharT, _Traits >::__num_put_type
inherited

These are non-standard types.

Definition at line 89 of file basic_ios.h.

◆ event_callback

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

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 529 of file ios_base.h.

◆ fmtflags

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

Definition at line 341 of file ios_base.h.

◆ iostate

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

Definition at line 416 of file ios_base.h.

◆ openmode

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

Definition at line 447 of file ios_base.h.

◆ seekdir

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.

Definition at line 479 of file ios_base.h.

Member Enumeration Documentation

◆ event

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().

Definition at line 512 of file ios_base.h.

Constructor & Destructor Documentation

◆ basic_ifstream() [1/4]

template<typename _CharT , typename _Traits >
std::basic_ifstream< _CharT, _Traits >::basic_ifstream ( )
inline

Default constructor.

Initializes sb using its default constructor, and passes &sb to the base class initializer. Does not open any files (you haven't given it a filename to open).

Definition at line 523 of file fstream.

References std::basic_ios< _CharT, _Traits >::init().

◆ basic_ifstream() [2/4]

template<typename _CharT , typename _Traits >
std::basic_ifstream< _CharT, _Traits >::basic_ifstream ( const char *  __s,
ios_base::openmode  __mode = ios_base::in 
)
inlineexplicit

Create an input file stream.

Parameters
__sNull terminated string specifying the filename.
__modeOpen file in specified mode (see std::ios_base).

ios_base::in is automatically included in __mode.

Definition at line 534 of file fstream.

References std::basic_ios< _CharT, _Traits >::init(), and std::basic_ifstream< _CharT, _Traits >::open().

◆ basic_ifstream() [3/4]

template<typename _CharT , typename _Traits >
std::basic_ifstream< _CharT, _Traits >::basic_ifstream ( const std::string __s,
ios_base::openmode  __mode = ios_base::in 
)
inlineexplicit

Create an input file stream.

Parameters
__sstd::string specifying the filename.
__modeOpen file in specified mode (see std::ios_base).

ios_base::in is automatically included in __mode.

Definition at line 567 of file fstream.

References std::basic_ios< _CharT, _Traits >::init(), and std::basic_ifstream< _CharT, _Traits >::open().

◆ basic_ifstream() [4/4]

template<typename _CharT , typename _Traits >
template<typename _Path , typename _Require = _If_fs_path<_Path>>
std::basic_ifstream< _CharT, _Traits >::basic_ifstream ( const _Path &  __s,
ios_base::openmode  __mode = ios_base::in 
)
inline

Create an input file stream.

Parameters
__sfilesystem::path specifying the filename.
__modeOpen file in specified mode (see std::ios_base).

ios_base::in is automatically included in __mode.

Definition at line 584 of file fstream.

◆ ~basic_ifstream()

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

The destructor does nothing.

The file is closed by the filebuf object, not the formatting stream.

Definition at line 604 of file fstream.

Member Function Documentation

◆ _M_getloc()

◆ bad()

template<typename _CharT , typename _Traits >
bool std::basic_ios< _CharT, _Traits >::bad ( ) const
inlineinherited

Fast error checking.

Returns
True if the badbit is set.

Note that other iostate flags may also be set.

Definition at line 211 of file basic_ios.h.

References std::ios_base::badbit, and std::basic_ios< _CharT, _Traits >::rdstate().

Referenced by std::basic_ostream< _CharT, _Traits >::sentry::sentry().

◆ clear()

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

◆ close()

template<typename _CharT , typename _Traits >
void std::basic_ifstream< _CharT, _Traits >::close ( )
inline

Close the file.

Calls std::basic_filebuf::close(). If that function fails, failbit is set in the stream's error state.

Definition at line 735 of file fstream.

References std::basic_filebuf< _CharT, _Traits >::close(), std::ios_base::failbit, and std::basic_ios< _CharT, _Traits >::setstate().

◆ copyfmt()

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

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 63 of file basic_ios.tcc.

References std::__addressof(), std::basic_ios< _CharT, _Traits >::exceptions(), std::basic_ios< _CharT, _Traits >::fill(), std::ios_base::flags(), std::ios_base::getloc(), std::ios_base::precision(), std::basic_ios< _CharT, _Traits >::tie(), std::tie(), and std::ios_base::width().

◆ eof()

template<typename _CharT , typename _Traits >
bool std::basic_ios< _CharT, _Traits >::eof ( ) const
inlineinherited

Fast error checking.

Returns
True if the eofbit is set.

Note that other iostate flags may also be set.

Definition at line 190 of file basic_ios.h.

References std::ios_base::eofbit, and std::basic_ios< _CharT, _Traits >::rdstate().

◆ exceptions() [1/2]

template<typename _CharT , typename _Traits >
iostate std::basic_ios< _CharT, _Traits >::exceptions ( ) const
inlineinherited

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 222 of file basic_ios.h.

Referenced by std::basic_ios< _CharT, _Traits >::copyfmt().

◆ exceptions() [2/2]

template<typename _CharT , typename _Traits >
void std::basic_ios< _CharT, _Traits >::exceptions ( iostate  __except)
inlineinherited

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";
std::cerr << "Setting exception mask\n";
}
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 output.
Controlling input for files.
Definition: fstream:498
iostate exceptions() const
Throwing exceptions on errors.
Definition: basic_ios.h:222
void setstate(iostate __state)
Sets additional flags in the error state.
Definition: basic_ios.h:157
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:420

Definition at line 257 of file basic_ios.h.

References std::basic_ios< _CharT, _Traits >::clear().

◆ fail()

template<typename _CharT , typename _Traits >
bool std::basic_ios< _CharT, _Traits >::fail ( ) const
inlineinherited

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 201 of file basic_ios.h.

References std::ios_base::badbit, std::ios_base::failbit, and std::basic_ios< _CharT, _Traits >::rdstate().

Referenced by std::basic_ios< _CharT, _Traits >::operator bool(), std::basic_ios< _CharT, _Traits >::operator!(), std::basic_ostream< _CharT, _Traits >::seekp(), and std::basic_ostream< _CharT, _Traits >::tellp().

◆ fill() [1/2]

template<typename _CharT , typename _Traits >
char_type std::basic_ios< _CharT, _Traits >::fill ( ) const
inlineinherited

Retrieves the empty character.

Returns
The current fill character.

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

Definition at line 370 of file basic_ios.h.

References std::basic_ios< _CharT, _Traits >::widen().

Referenced by std::basic_ios< _CharT, _Traits >::copyfmt(), and std::basic_ios< _CharT, _Traits >::fill().

◆ fill() [2/2]

template<typename _CharT , typename _Traits >
char_type std::basic_ios< _CharT, _Traits >::fill ( char_type  __ch)
inlineinherited

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 390 of file basic_ios.h.

References std::basic_ios< _CharT, _Traits >::fill().

◆ flags() [1/2]

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

◆ flags() [2/2]

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

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 660 of file ios_base.h.

◆ gcount()

template<typename _CharT , typename _Traits >
streamsize std::basic_istream< _CharT, _Traits >::gcount ( ) const
inlineinherited

Character counting.

Returns
The number of characters extracted by the previous unformatted input function dispatched for this stream.

Definition at line 269 of file istream.

References std::basic_istream< _CharT, _Traits >::_M_gcount.

◆ get() [1/6]

template<typename _CharT , typename _Traits >
basic_istream< _CharT, _Traits >::int_type std::basic_istream< _CharT, _Traits >::get ( void  )
inherited

Simple extraction.

Returns
A character, or eof().

Tries to extract a character. If none are available, sets failbit and returns traits::eof().

Definition at line 243 of file istream.tcc.

References std::basic_istream< _CharT, _Traits >::_M_gcount, and std::ios_base::goodbit.

Referenced by std::basic_istream< _CharT, _Traits >::get().

◆ get() [2/6]

template<typename _CharT , typename _Traits >
__istream_type& std::basic_istream< _CharT, _Traits >::get ( __streambuf_type __sb)
inlineinherited

Extraction into another streambuf.

Parameters
__sbA streambuf in which to store data.
Returns
*this

Returns get(__sb,widen('\n')).

Definition at line 387 of file istream.

References std::basic_istream< _CharT, _Traits >::get(), and std::basic_ios< _CharT, _Traits >::widen().

◆ get() [3/6]

template<typename _CharT , typename _Traits >
basic_istream< _CharT, _Traits > & std::basic_istream< _CharT, _Traits >::get ( __streambuf_type __sb,
char_type  __delim 
)
inherited

Extraction into another streambuf.

Parameters
__sbA streambuf in which to store data.
__delimA "stop" character.
Returns
*this

Characters are extracted and inserted into __sb until one of the following happens:

  • the input sequence reaches EOF
  • insertion into the output buffer fails (in this case, the character that would have been inserted is not extracted)
  • the next character equals __delim (in this case, the character is not extracted)
  • an exception occurs (and in this case is caught)

If no characters are stored, failbit is set in the stream's error state.

Definition at line 363 of file istream.tcc.

References std::basic_istream< _CharT, _Traits >::_M_gcount, and std::ios_base::goodbit.

◆ get() [4/6]

template<typename _CharT , typename _Traits >
basic_istream< _CharT, _Traits > & std::basic_istream< _CharT, _Traits >::get ( char_type &  __c)
inherited

Simple extraction.

Parameters
__cThe character in which to store data.
Returns
*this

Tries to extract a character and store it in __c. If none are available, sets failbit and returns traits::eof().

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

Definition at line 279 of file istream.tcc.

References std::basic_istream< _CharT, _Traits >::_M_gcount, and std::ios_base::goodbit.

◆ get() [5/6]

template<typename _CharT , typename _Traits >
__istream_type& std::basic_istream< _CharT, _Traits >::get ( char_type *  __s,
streamsize  __n 
)
inlineinherited

Simple multiple-character extraction.

Parameters
__sPointer to an array.
__nMaximum number of characters to store in s.
Returns
*this

Returns get(__s,__n,widen('\n')).

Definition at line 354 of file istream.

References std::basic_istream< _CharT, _Traits >::get(), and std::basic_ios< _CharT, _Traits >::widen().

◆ get() [6/6]

template<typename _CharT , typename _Traits >
basic_istream< _CharT, _Traits > & std::basic_istream< _CharT, _Traits >::get ( char_type *  __s,
streamsize  __n,
char_type  __delim 
)
inherited

Simple multiple-character extraction.

Parameters
__sPointer to an array.
__nMaximum number of characters to store in __s.
__delimA "stop" character.
Returns
*this

Characters are extracted and stored into __s until one of the following happens:

  • __n-1 characters are stored
  • the input sequence reaches EOF
  • the next character equals __delim, in which case the character is not extracted

If no characters are stored, failbit is set in the stream's error state.

In any case, a null character is stored into the next location in the array.

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

Definition at line 316 of file istream.tcc.

References std::basic_istream< _CharT, _Traits >::_M_gcount, and std::ios_base::goodbit.

◆ getline() [1/3]

template<typename _CharT , typename _Traits >
__istream_type& std::basic_istream< _CharT, _Traits >::getline ( char_type *  __s,
streamsize  __n 
)
inlineinherited

String extraction.

Parameters
__sA character array in which to store the data.
__nMaximum number of characters to extract.
Returns
*this

Returns getline(__s,__n,widen('\n')).

Definition at line 427 of file istream.

References std::basic_istream< _CharT, _Traits >::getline(), and std::basic_ios< _CharT, _Traits >::widen().

◆ getline() [2/3]

template<typename _CharT , typename _Traits >
basic_istream< _CharT, _Traits > & std::basic_istream< _CharT, _Traits >::getline ( char_type *  __s,
streamsize  __n,
char_type  __delim 
)
inherited

String extraction.

Parameters
__sA character array in which to store the data.
__nMaximum number of characters to extract.
__delimA "stop" character.
Returns
*this

Extracts and stores characters into __s until one of the following happens. Note that these criteria are required to be tested in the order listed here, to allow an input line to exactly fill the __s array without setting failbit.

  1. the input sequence reaches end-of-file, in which case eofbit is set in the stream error state
  2. the next character equals __delim, in which case the character is extracted (and therefore counted in gcount()) but not stored
  3. __n-1 characters are stored, in which case failbit is set in the stream error state

If no characters are extracted, failbit is set. (An empty line of input should therefore not cause failbit to be set.)

In any case, a null character is stored in the next location in the array.

Definition at line 414 of file istream.tcc.

Referenced by std::basic_istream< _CharT, _Traits >::getline().

◆ getline() [3/3]

basic_istream< char > & std::basic_istream< char >::getline ( char_type *  __s,
streamsize  __n,
char_type  __delim 
)
inherited

Explicit specialization declarations, defined in src/istream.cc.

◆ getloc()

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

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 793 of file ios_base.h.

Referenced by std::basic_ios< _CharT, _Traits >::copyfmt(), and std::money_put< _CharT, _OutIter >::do_put().

◆ good()

template<typename _CharT , typename _Traits >
bool std::basic_ios< _CharT, _Traits >::good ( ) const
inlineinherited

Fast error checking.

Returns
True if no error flags are set.

A wrapper around rdstate.

Definition at line 180 of file basic_ios.h.

References std::basic_ios< _CharT, _Traits >::rdstate().

Referenced by std::basic_istream< _CharT, _Traits >::sentry::sentry(), std::basic_ostream< _CharT, _Traits >::sentry::sentry(), and std::__detail::operator>>().

◆ ignore() [1/3]

template<typename _CharT , typename _Traits >
basic_istream< _CharT, _Traits > & std::basic_istream< _CharT, _Traits >::ignore ( void  )
inherited

Simple extraction.

Returns
A character, or eof().

Tries to extract a character. If none are available, sets failbit and returns traits::eof().

Definition at line 474 of file istream.tcc.

References std::basic_istream< _CharT, _Traits >::_M_gcount, and std::ios_base::goodbit.

◆ ignore() [2/3]

template<typename _CharT , typename _Traits >
basic_istream< _CharT, _Traits > & std::basic_istream< _CharT, _Traits >::ignore ( streamsize  __n)
inherited

Simple extraction.

Returns
A character, or eof().

Tries to extract a character. If none are available, sets failbit and returns traits::eof().

Definition at line 507 of file istream.tcc.

References std::basic_istream< _CharT, _Traits >::_M_gcount, and std::ios_base::goodbit.

◆ ignore() [3/3]

template<typename _CharT , typename _Traits >
basic_istream< _CharT, _Traits > & std::basic_istream< _CharT, _Traits >::ignore ( streamsize  __n,
int_type  __delim 
)
inherited

Discarding characters.

Parameters
__nNumber of characters to discard.
__delimA "stop" character.
Returns
*this

Extracts characters and throws them away until one of the following happens:

  • if __n != std::numeric_limits<int>::max(), __n characters are extracted
  • the input sequence reaches end-of-file
  • the next character equals __delim (in this case, the character is extracted); note that this condition will never occur if __delim equals traits::eof().

NB: Provide three overloads, instead of the single function (with defaults) mandated by the Standard: this leads to a better performing implementation, while still conforming to the Standard.

Definition at line 577 of file istream.tcc.

References std::basic_istream< _CharT, _Traits >::_M_gcount, and std::ios_base::goodbit.

◆ imbue()

template<typename _CharT , typename _Traits >
locale std::basic_ios< _CharT, _Traits >::imbue ( const locale __loc)
inherited

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 http://gcc.gnu.org/onlinedocs/libstdc++/manual/localization.html

Definition at line 114 of file basic_ios.tcc.

References std::ios_base::imbue().

◆ init()

◆ is_open()

template<typename _CharT , typename _Traits >
bool std::basic_ifstream< _CharT, _Traits >::is_open ( )
inline

Wrapper to test for an open file.

Returns
rdbuf()->is_open()

Definition at line 645 of file fstream.

References std::basic_filebuf< _CharT, _Traits >::is_open().

◆ iword()

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

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 839 of file ios_base.h.

◆ narrow()

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

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

std::use_facet<ctype<char_type> >(getloc()).narrow(c,dfault)
char narrow(char_type __c, char __dfault) const
Squeezes characters.
Definition: basic_ios.h:430
locale getloc() const
Locale access.
Definition: ios_base.h:793

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

Definition at line 430 of file basic_ios.h.

◆ open() [1/3]

template<typename _CharT , typename _Traits >
template<typename _Path >
_If_fs_path<_Path, void> std::basic_ifstream< _CharT, _Traits >::open ( const _Path &  __s,
ios_base::openmode  __mode = ios_base::in 
)
inline

Opens an external file.

Parameters
__sThe name of the file, as a filesystem::path.
__modeThe open mode flags.

Calls std::basic_filebuf::open(__s,__mode|in). If that function fails, failbit is set in the stream's error state.

Definition at line 723 of file fstream.

References std::basic_ifstream< _CharT, _Traits >::open().

◆ open() [2/3]

template<typename _CharT , typename _Traits >
void std::basic_ifstream< _CharT, _Traits >::open ( const char *  __s,
ios_base::openmode  __mode = ios_base::in 
)
inline

Opens an external file.

Parameters
__sThe name of the file.
__modeThe open mode flags.

Calls std::basic_filebuf::open(s,__mode|in). If that function fails, failbit is set in the stream's error state.

Definition at line 663 of file fstream.

References std::basic_ios< _CharT, _Traits >::clear(), std::ios_base::failbit, std::ios_base::in, std::basic_filebuf< _CharT, _Traits >::open(), and std::basic_ios< _CharT, _Traits >::setstate().

Referenced by std::basic_ifstream< _CharT, _Traits >::basic_ifstream(), and std::basic_ifstream< _CharT, _Traits >::open().

◆ open() [3/3]

template<typename _CharT , typename _Traits >
void std::basic_ifstream< _CharT, _Traits >::open ( const std::string __s,
ios_base::openmode  __mode = ios_base::in 
)
inline

Opens an external file.

Parameters
__sThe name of the file.
__modeThe open mode flags.

Calls std::basic_filebuf::open(__s,__mode|in). If that function fails, failbit is set in the stream's error state.

Definition at line 702 of file fstream.

References std::basic_ios< _CharT, _Traits >::clear(), std::ios_base::failbit, std::ios_base::in, std::basic_filebuf< _CharT, _Traits >::open(), and std::basic_ios< _CharT, _Traits >::setstate().

◆ operator bool()

template<typename _CharT , typename _Traits >
std::basic_ios< _CharT, _Traits >::operator bool ( ) const
inlineexplicitinherited

The quick-and-easy status check.

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

Definition at line 117 of file basic_ios.h.

References std::basic_ios< _CharT, _Traits >::fail().

◆ operator!()

template<typename _CharT , typename _Traits >
bool std::basic_ios< _CharT, _Traits >::operator! ( ) const
inlineinherited

The quick-and-easy status check.

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

Definition at line 125 of file basic_ios.h.

References std::basic_ios< _CharT, _Traits >::fail().

◆ operator>>() [1/17]

template<typename _CharT , typename _Traits >
__istream_type& std::basic_istream< _CharT, _Traits >::operator>> ( __ios_type &(*)(__ios_type &)  __pf)
inlineinherited

Interface for manipulators.

Manipulators such as std::ws and std::dec use these functions in constructs like std::cin >> std::ws. For more information, see the iomanip header.

Definition at line 124 of file istream.

◆ operator>>() [2/17]

template<typename _CharT , typename _Traits >
__istream_type& std::basic_istream< _CharT, _Traits >::operator>> ( __istream_type &(*)(__istream_type &)  __pf)
inlineinherited

Interface for manipulators.

Manipulators such as std::ws and std::dec use these functions in constructs like std::cin >> std::ws. For more information, see the iomanip header.

Definition at line 120 of file istream.

◆ operator>>() [3/17]

template<typename _CharT , typename _Traits >
basic_istream< _CharT, _Traits > & std::basic_istream< _CharT, _Traits >::operator>> ( __streambuf_type __sb)
inherited

Extracting into 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 this stream and inserted into the __sb streambuf until one of the following occurs:

  • the input stream reaches end-of-file,
  • insertion into the output buffer fails (in this case, the character that would have been inserted is not extracted), or
  • an exception occurs (and in this case is caught)

If the function inserts no characters, failbit is set.

Definition at line 211 of file istream.tcc.

References std::ios_base::goodbit.

◆ operator>>() [4/17]

template<typename _CharT , typename _Traits >
__istream_type& std::basic_istream< _CharT, _Traits >::operator>> ( bool &  __n)
inlineinherited

Integer arithmetic extractors.

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 parse the input data.

Definition at line 168 of file istream.

◆ operator>>() [5/17]

template<typename _CharT , typename _Traits >
__istream_type& std::basic_istream< _CharT, _Traits >::operator>> ( double &  __f)
inlineinherited

Floating point arithmetic extractors.

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 parse the input data.

Definition at line 218 of file istream.

◆ operator>>() [6/17]

template<typename _CharT , typename _Traits >
__istream_type& std::basic_istream< _CharT, _Traits >::operator>> ( float &  __f)
inlineinherited

Floating point arithmetic extractors.

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 parse the input data.

Definition at line 214 of file istream.

◆ operator>>() [7/17]

template<typename _CharT , typename _Traits >
basic_istream< _CharT, _Traits > & std::basic_istream< _CharT, _Traits >::operator>> ( int &  __n)
inherited

Integer arithmetic extractors.

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 parse the input data.

Definition at line 166 of file istream.tcc.

◆ operator>>() [8/17]

template<typename _CharT , typename _Traits >
__istream_type& std::basic_istream< _CharT, _Traits >::operator>> ( ios_base &(*)(ios_base &)  __pf)
inlineinherited

Interface for manipulators.

Manipulators such as std::ws and std::dec use these functions in constructs like std::cin >> std::ws. For more information, see the iomanip header.

Definition at line 131 of file istream.

◆ operator>>() [9/17]

template<typename _CharT , typename _Traits >
__istream_type& std::basic_istream< _CharT, _Traits >::operator>> ( long &  __n)
inlineinherited

Integer arithmetic extractors.

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 parse the input data.

Definition at line 186 of file istream.

◆ operator>>() [10/17]

template<typename _CharT , typename _Traits >
__istream_type& std::basic_istream< _CharT, _Traits >::operator>> ( long double &  __f)
inlineinherited

Floating point arithmetic extractors.

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 parse the input data.

Definition at line 222 of file istream.

◆ operator>>() [11/17]

template<typename _CharT , typename _Traits >
__istream_type& std::basic_istream< _CharT, _Traits >::operator>> ( long long &  __n)
inlineinherited

Integer arithmetic extractors.

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 parse the input data.

Definition at line 195 of file istream.

◆ operator>>() [12/17]

template<typename _CharT , typename _Traits >
basic_istream< _CharT, _Traits > & std::basic_istream< _CharT, _Traits >::operator>> ( short &  __n)
inherited

Integer arithmetic extractors.

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 parse the input data.

Definition at line 121 of file istream.tcc.

References std::ios_base::goodbit.

◆ operator>>() [13/17]

template<typename _CharT , typename _Traits >
__istream_type& std::basic_istream< _CharT, _Traits >::operator>> ( unsigned int &  __n)
inlineinherited

Integer arithmetic extractors.

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 parse the input data.

Definition at line 182 of file istream.

◆ operator>>() [14/17]

template<typename _CharT , typename _Traits >
__istream_type& std::basic_istream< _CharT, _Traits >::operator>> ( unsigned long &  __n)
inlineinherited

Integer arithmetic extractors.

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 parse the input data.

Definition at line 190 of file istream.

◆ operator>>() [15/17]

template<typename _CharT , typename _Traits >
__istream_type& std::basic_istream< _CharT, _Traits >::operator>> ( unsigned long long &  __n)
inlineinherited

Integer arithmetic extractors.

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 parse the input data.

Definition at line 199 of file istream.

◆ operator>>() [16/17]

template<typename _CharT , typename _Traits >
__istream_type& std::basic_istream< _CharT, _Traits >::operator>> ( unsigned short &  __n)
inlineinherited

Integer arithmetic extractors.

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 parse the input data.

Definition at line 175 of file istream.

◆ operator>>() [17/17]

template<typename _CharT , typename _Traits >
__istream_type& std::basic_istream< _CharT, _Traits >::operator>> ( void *&  __p)
inlineinherited

Basic arithmetic extractors.

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

These functions use the stream's current locale (specifically, the num_get facet) to parse the input data.

Definition at line 235 of file istream.

◆ peek()

template<typename _CharT , typename _Traits >
basic_istream< _CharT, _Traits >::int_type std::basic_istream< _CharT, _Traits >::peek ( void  )
inherited

Looking ahead in the stream.

Returns
The next character, or eof().

If, after constructing the sentry object, good() is false, returns traits::eof(). Otherwise reads but does not extract the next input character.

Definition at line 654 of file istream.tcc.

References std::basic_istream< _CharT, _Traits >::_M_gcount, and std::ios_base::goodbit.

◆ precision() [1/2]

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

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 719 of file ios_base.h.

Referenced by std::basic_ios< _CharT, _Traits >::copyfmt().

◆ precision() [2/2]

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

Changing flags.

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

Definition at line 728 of file ios_base.h.

◆ putback()

template<typename _CharT , typename _Traits >
basic_istream< _CharT, _Traits > & std::basic_istream< _CharT, _Traits >::putback ( char_type  __c)
inherited

Unextracting a single character.

Parameters
__cThe character to push back into the input stream.
Returns
*this

If rdbuf() is not null, calls rdbuf()->sputbackc(c).

If rdbuf() is null or if sputbackc() fails, sets badbit in the error state.

Note
This function first clears eofbit. Since no characters are extracted, the next call to gcount() will return 0, as required by DR 60.

Definition at line 745 of file istream.tcc.

References std::basic_istream< _CharT, _Traits >::_M_gcount, std::basic_ios< _CharT, _Traits >::clear(), std::ios_base::eofbit, std::ios_base::goodbit, and std::basic_ios< _CharT, _Traits >::rdstate().

Referenced by std::operator<<().

◆ pword()

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

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 860 of file ios_base.h.

◆ rdbuf() [1/2]

template<typename _CharT , typename _Traits >
__filebuf_type* std::basic_ifstream< _CharT, _Traits >::rdbuf ( ) const
inline

Accessing the underlying buffer.

Returns
The current basic_filebuf buffer.

This hides both signatures of std::basic_ios::rdbuf().

Definition at line 637 of file fstream.

◆ rdbuf() [2/2]

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

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>
Controlling input and output for files.
Definition: fstream:1022
The actual work of input and output (interface).
Definition: streambuf:123

Definition at line 53 of file basic_ios.tcc.

◆ rdstate()

template<typename _CharT , typename _Traits >
iostate std::basic_ios< _CharT, _Traits >::rdstate ( ) const
inlineinherited

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 137 of file basic_ios.h.

Referenced by std::basic_ios< _CharT, _Traits >::bad(), std::basic_ios< _CharT, _Traits >::eof(), std::basic_ios< _CharT, _Traits >::fail(), std::basic_ios< _CharT, _Traits >::good(), std::basic_istream< _CharT, _Traits >::putback(), std::basic_istream< _CharT, _Traits >::seekg(), std::basic_ios< _CharT, _Traits >::setstate(), and std::basic_istream< _CharT, _Traits >::unget().

◆ read()

template<typename _CharT , typename _Traits >
basic_istream< _CharT, _Traits > & std::basic_istream< _CharT, _Traits >::read ( char_type *  __s,
streamsize  __n 
)
inherited

Extraction without delimiters.

Parameters
__sA character array.
__nMaximum number of characters to store.
Returns
*this

If the stream state is good(), extracts characters and stores them into __s until one of the following happens:

  • __n characters are stored
  • the input sequence reaches end-of-file, in which case the error state is set to failbit|eofbit.
Note
This function is not overloaded on signed char and unsigned char.

Definition at line 684 of file istream.tcc.

References std::basic_istream< _CharT, _Traits >::_M_gcount, and std::ios_base::goodbit.

◆ readsome()

template<typename _CharT , typename _Traits >
streamsize std::basic_istream< _CharT, _Traits >::readsome ( char_type *  __s,
streamsize  __n 
)
inherited

Extraction until the buffer is exhausted, but no more.

Parameters
__sA character array.
__nMaximum number of characters to store.
Returns
The number of characters extracted.

Extracts characters and stores them into __s depending on the number of characters remaining in the streambuf's buffer, rdbuf()->in_avail(), called A here:

  • if A == -1, sets eofbit and extracts no characters
  • if A == 0, extracts no characters
  • if A > 0, extracts min(A,n)

The goal is to empty the current buffer, and to not request any more from the external input sequence controlled by the streambuf.

Definition at line 713 of file istream.tcc.

References std::basic_istream< _CharT, _Traits >::_M_gcount, and std::ios_base::goodbit.

◆ register_callback()

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

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.

◆ seekg() [1/2]

template<typename _CharT , typename _Traits >
basic_istream< _CharT, _Traits > & std::basic_istream< _CharT, _Traits >::seekg ( off_type  __off,
ios_base::seekdir  __dir 
)
inherited

Changing the current read 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.

Note
This function first clears eofbit. It does not count the number of characters extracted, if any, and therefore does not affect the next call to gcount().

Definition at line 918 of file istream.tcc.

References std::basic_ios< _CharT, _Traits >::clear(), std::ios_base::eofbit, std::ios_base::goodbit, and std::basic_ios< _CharT, _Traits >::rdstate().

◆ seekg() [2/2]

template<typename _CharT , typename _Traits >
basic_istream< _CharT, _Traits > & std::basic_istream< _CharT, _Traits >::seekg ( pos_type  __pos)
inherited

Changing the current read position.

Parameters
__posA file position object.
Returns
*this

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

Note
This function first clears eofbit. It does not count the number of characters extracted, if any, and therefore does not affect the next call to gcount().

Definition at line 879 of file istream.tcc.

References std::basic_ios< _CharT, _Traits >::clear(), std::ios_base::eofbit, std::ios_base::goodbit, and std::basic_ios< _CharT, _Traits >::rdstate().

◆ setf() [1/2]

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

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 676 of file ios_base.h.

Referenced by std::__detail::operator>>().

◆ setf() [2/2]

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

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 693 of file ios_base.h.

◆ setstate()

◆ sync()

template<typename _CharT , typename _Traits >
int std::basic_istream< _CharT, _Traits >::sync ( void  )
inherited

Synchronizing the stream buffer.

Returns
0 on success, -1 on failure

If rdbuf() is a null pointer, returns -1.

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

Otherwise, returns 0.

Note
This function does not count the number of characters extracted, if any, and therefore does not affect the next call to gcount().

Definition at line 815 of file istream.tcc.

References std::ios_base::goodbit.

◆ sync_with_stdio()

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

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

◆ tellg()

template<typename _CharT , typename _Traits >
basic_istream< _CharT, _Traits >::pos_type std::basic_istream< _CharT, _Traits >::tellg ( void  )
inherited

Getting the current read position.

Returns
A file position object.

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

Note
This function does not count the number of characters extracted, if any, and therefore does not affect the next call to gcount(). At variance with putback, unget and seekg, eofbit is not cleared first.

Definition at line 851 of file istream.tcc.

◆ tie() [1/2]

template<typename _CharT , typename _Traits >
basic_ostream<_CharT, _Traits>* std::basic_ios< _CharT, _Traits >::tie ( ) const
inlineinherited

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 295 of file basic_ios.h.

Referenced by std::basic_ostream< _CharT, _Traits >::sentry::sentry(), and std::basic_ios< _CharT, _Traits >::copyfmt().

◆ tie() [2/2]

template<typename _CharT , typename _Traits >
basic_ostream<_CharT, _Traits>* std::basic_ios< _CharT, _Traits >::tie ( basic_ostream< _CharT, _Traits > *  __tiestr)
inlineinherited

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 307 of file basic_ios.h.

◆ unget()

template<typename _CharT , typename _Traits >
basic_istream< _CharT, _Traits > & std::basic_istream< _CharT, _Traits >::unget ( void  )
inherited

Unextracting the previous character.

Returns
*this

If rdbuf() is not null, calls rdbuf()->sungetc(c).

If rdbuf() is null or if sungetc() fails, sets badbit in the error state.

Note
This function first clears eofbit. Since no characters are extracted, the next call to gcount() will return 0, as required by DR 60.

Definition at line 780 of file istream.tcc.

References std::basic_istream< _CharT, _Traits >::_M_gcount, std::basic_ios< _CharT, _Traits >::clear(), std::ios_base::eofbit, std::ios_base::goodbit, and std::basic_ios< _CharT, _Traits >::rdstate().

Referenced by std::__detail::operator>>().

◆ unsetf()

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

Clearing format flags.

Parameters
__maskThe flags to unset.

This function clears __mask in the format flags.

Definition at line 708 of file ios_base.h.

◆ widen()

template<typename _CharT , typename _Traits >
char_type std::basic_ios< _CharT, _Traits >::widen ( char  __c) const
inlineinherited

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

std::use_facet<ctype<char_type> >(getloc()).widen(c)
char_type widen(char __c) const
Widens characters.
Definition: basic_ios.h:449

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

Definition at line 449 of file basic_ios.h.

Referenced by std::endl(), std::basic_ios< _CharT, _Traits >::fill(), std::basic_istream< _CharT, _Traits >::get(), std::getline(), std::basic_istream< _CharT, _Traits >::getline(), std::operator<<(), and std::tr2::operator>>().

◆ width() [1/2]

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

Flags access.

Returns
The minimum field width to generate on output operations.

Minimum field width refers to the number of characters.

Definition at line 742 of file ios_base.h.

Referenced by std::basic_ios< _CharT, _Traits >::copyfmt(), and std::num_put< _CharT, _OutIter >::do_put().

◆ width() [2/2]

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

Changing flags.

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

Definition at line 751 of file ios_base.h.

◆ xalloc()

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

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

◆ _M_gcount

◆ adjustfield

const fmtflags std::ios_base::adjustfield
staticinherited

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

Definition at line 396 of file ios_base.h.

Referenced by std::num_put< _CharT, _OutIter >::do_put(), std::internal(), std::left(), and std::right().

◆ app

const openmode std::ios_base::app
staticinherited

◆ ate

const openmode std::ios_base::ate
staticinherited

Open and seek to end immediately after opening.

Definition at line 453 of file ios_base.h.

Referenced by std::basic_filebuf< _CharT, _Traits >::open().

◆ badbit

const iostate std::ios_base::badbit
staticinherited

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

Definition at line 420 of file ios_base.h.

Referenced by std::basic_ostream< _CharT, _Traits >::sentry::~sentry(), std::basic_ios< _CharT, _Traits >::bad(), std::basic_ios< _CharT, _Traits >::fail(), std::basic_istream< char >::get(), and std::basic_istream< char >::ignore().

◆ basefield

const fmtflags std::ios_base::basefield
staticinherited

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

Definition at line 399 of file ios_base.h.

Referenced by std::dec(), std::num_get< _CharT, _InIter >::do_get(), std::num_put< _CharT, _OutIter >::do_put(), std::hex(), and std::oct().

◆ beg

const seekdir std::ios_base::beg
staticinherited

Request a seek relative to the beginning of the stream.

Definition at line 482 of file ios_base.h.

Referenced by std::basic_filebuf< _CharT, _Traits >::seekpos(), and __gnu_cxx::stdio_sync_filebuf< _CharT, _Traits >::seekpos().

◆ binary

const openmode std::ios_base::binary
staticinherited

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 458 of file ios_base.h.

Referenced by std::basic_filebuf< _CharT, _Traits >::showmanyc().

◆ boolalpha

const fmtflags std::ios_base::boolalpha
staticinherited

Insert/extract bool in alphabetic rather than numeric format.

Definition at line 344 of file ios_base.h.

Referenced by std::boolalpha(), std::num_get< _CharT, _InIter >::do_get(), std::num_put< _CharT, _OutIter >::do_put(), and std::noboolalpha().

◆ cur

◆ dec

const fmtflags std::ios_base::dec
staticinherited

Converts integer input or generates integer output in decimal base.

Definition at line 347 of file ios_base.h.

Referenced by std::dec().

◆ end

const seekdir std::ios_base::end
staticinherited

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

Definition at line 488 of file ios_base.h.

Referenced by std::basic_filebuf< _CharT, _Traits >::open(), and std::basic_stringbuf< _CharT, _Traits, _Alloc >::seekoff().

◆ eofbit

◆ failbit

◆ fixed

const fmtflags std::ios_base::fixed
staticinherited

Generate floating-point output in fixed-point notation.

Definition at line 350 of file ios_base.h.

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

◆ floatfield

const fmtflags std::ios_base::floatfield
staticinherited

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

Definition at line 402 of file ios_base.h.

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

◆ goodbit

◆ hex

const fmtflags std::ios_base::hex
staticinherited

Converts integer input or generates integer output in hexadecimal base.

Definition at line 353 of file ios_base.h.

Referenced by std::num_get< _CharT, _InIter >::do_get(), std::num_put< _CharT, _OutIter >::do_put(), and std::hex().

◆ in

◆ internal

const fmtflags std::ios_base::internal
staticinherited

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 358 of file ios_base.h.

Referenced by std::internal().

◆ left

const fmtflags std::ios_base::left
staticinherited

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

Definition at line 362 of file ios_base.h.

Referenced by std::num_put< _CharT, _OutIter >::do_put(), and std::left().

◆ oct

const fmtflags std::ios_base::oct
staticinherited

Converts integer input or generates integer output in octal base.

Definition at line 365 of file ios_base.h.

Referenced by std::oct().

◆ out

◆ right

const fmtflags std::ios_base::right
staticinherited

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

Definition at line 369 of file ios_base.h.

Referenced by std::right().

◆ scientific

const fmtflags std::ios_base::scientific
staticinherited

Generates floating-point output in scientific notation.

Definition at line 372 of file ios_base.h.

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

◆ showbase

const fmtflags std::ios_base::showbase
staticinherited

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

Definition at line 376 of file ios_base.h.

Referenced by std::num_put< _CharT, _OutIter >::do_put(), std::noshowbase(), and std::showbase().

◆ showpoint

const fmtflags std::ios_base::showpoint
staticinherited

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

Definition at line 380 of file ios_base.h.

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

◆ showpos

const fmtflags std::ios_base::showpos
staticinherited

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

Definition at line 383 of file ios_base.h.

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

◆ skipws

const fmtflags std::ios_base::skipws
staticinherited

Skips leading white space before certain input operations.

Definition at line 386 of file ios_base.h.

Referenced by std::noskipws(), std::__detail::operator>>(), and std::skipws().

◆ trunc

const openmode std::ios_base::trunc
staticinherited

Truncate an existing stream when opening. Default for ofstream.

Definition at line 467 of file ios_base.h.

◆ unitbuf

const fmtflags std::ios_base::unitbuf
staticinherited

Flushes output after each output operation.

Definition at line 389 of file ios_base.h.

Referenced by std::basic_ostream< _CharT, _Traits >::sentry::~sentry(), std::nounitbuf(), and std::unitbuf().

◆ uppercase

const fmtflags std::ios_base::uppercase
staticinherited

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

Definition at line 393 of file ios_base.h.

Referenced by std::num_put< _CharT, _OutIter >::do_put(), std::nouppercase(), and std::uppercase().


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