std::basic_ifstream< _CharT, _Traits >(3cxx) | std::basic_ifstream< _CharT, _Traits >(3cxx) |
NAME¶
std::basic_ifstream< _CharT, _Traits > - Controlling input for files.
SYNOPSIS¶
Inherits std::basic_istream< _CharT, _Traits >.
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 }
The set of events that may be passed to an event callback. typedef void(*
event_callback) (event __e, ios_base &__b, int __i)
The type of an event callback function. typedef _Ios_Fmtflags fmtflags
This is a bitmask type. typedef traits_type::int_type int_type
typedef _Ios_Iostate iostate
This is a bitmask type. typedef traits_type::off_type off_type
typedef _Ios_Openmode openmode
This is a bitmask type. typedef traits_type::pos_type pos_type
typedef _Ios_Seekdir seekdir
This is an enumerated type. typedef _Traits traits_type
typedef num_put< _CharT, ostreambuf_iterator< _CharT,
_Traits > > __num_put_type
Public Member Functions¶
basic_ifstream ()
Default constructor. 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)
Create an input file stream. basic_ifstream (const
basic_ifstream &)=delete
basic_ifstream (const char *__s, ios_base::openmode
__mode=ios_base::in)
Create an input file stream. basic_ifstream (const std::string
&__s, ios_base::openmode __mode=ios_base::in)
Create an input file stream. ~basic_ifstream ()
The destructor does nothing. template<typename _ValueT >
basic_istream< _CharT, _Traits > & _M_extract
(_ValueT &__v)
const locale & _M_getloc () const
Locale access. void _M_setstate (iostate __state)
bool bad () const
Fast error checking. void clear (iostate __state=goodbit)
[Re]sets the error state. void close ()
Close the file. basic_ios & copyfmt (const basic_ios
&__rhs)
Copies fields of __rhs into this. bool eof () const
Fast error checking. iostate exceptions () const
Throwing exceptions on errors. void exceptions (iostate
__except)
Throwing exceptions on errors. bool fail () const
Fast error checking. char_type fill () const
Retrieves the empty character. char_type fill (char_type __ch)
Sets a new empty character. fmtflags flags () const
Access to format flags. fmtflags flags (fmtflags __fmtfl)
Setting new format flags all at once. streamsize gcount () const
Character counting. basic_istream< char > & getline
(char_type *__s, streamsize __n, char_type __delim)
Explicit specialization declarations, defined in src/istream.cc.
basic_istream< wchar_t > & getline (char_type *__s,
streamsize __n, char_type __delim)
locale getloc () const
Locale access. bool good () const
Fast error checking. 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)
Moves to a new locale. bool is_open ()
Wrapper to test for an open file. bool is_open () const
long & iword (int __ix)
Access to integer array. char narrow (char_type __c, char __dfault)
const
Squeezes characters. template<typename _Path > _If_fs_path< _Path,
void > open (const _Path &__s, ios_base::openmode
__mode=ios_base::in)
Opens an external file. void open (const char *__s,
ios_base::openmode __mode=ios_base::in)
Opens an external file. void open (const std::string &__s,
ios_base::openmode __mode=ios_base::in)
Opens an external file. basic_ifstream & operator=
(basic_ifstream &&__rhs)
basic_ifstream & operator= (const basic_ifstream
&)=delete
__istream_type & operator>> (__streambuf_type
*__sb)
Extracting into another streambuf. __istream_type &
operator>> (void *&__p)
Basic arithmetic extractors. streamsize precision () const
Flags access. streamsize precision (streamsize __prec)
Changing flags. void *& pword (int __ix)
Access to void pointer array. __filebuf_type * rdbuf () const
Accessing the underlying buffer. basic_streambuf< _CharT, _Traits
> * rdbuf (basic_streambuf< _CharT, _Traits > *__sb)
Changing the underlying buffer. iostate rdstate () const
Returns the error state of the stream buffer. void register_callback
(event_callback __fn, int __index)
Add the callback __fn with parameter __index. fmtflags setf
(fmtflags __fmtfl)
Setting new format flags. fmtflags setf (fmtflags
__fmtfl, fmtflags __mask)
Setting new format flags. void setstate (iostate __state)
Sets additional flags in the error state. void swap
(basic_ifstream &__rhs)
basic_ostream< _CharT, _Traits > * tie () const
Fetches the current tied stream. basic_ostream< _CharT,
_Traits > * tie (basic_ostream< _CharT, _Traits >
*__tiestr)
Ties this stream to an output stream. void unsetf (fmtflags
__mask)
Clearing format flags. char_type widen (char __c) const
Widens characters. streamsize width () const
Flags access. streamsize width (streamsize __wide)
Changing flags.
__istream_type & operator>> (__istream_type
&(*__pf)(__istream_type &))
Interface for manipulators. __istream_type &
operator>> (__ios_type &(*__pf)(__ios_type
&))
Interface for manipulators. __istream_type &
operator>> (ios_base &(*__pf)(ios_base
&))
Interface for manipulators.
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_type & operator>> (bool &__n)
Integer arithmetic extractors. __istream_type &
operator>> (short &__n)
Integer arithmetic extractors. __istream_type &
operator>> (unsigned short &__n)
Integer arithmetic extractors. __istream_type &
operator>> (int &__n)
Integer arithmetic extractors. __istream_type &
operator>> (unsigned int &__n)
Integer arithmetic extractors. __istream_type &
operator>> (long &__n)
Integer arithmetic extractors. __istream_type &
operator>> (unsigned long &__n)
Integer arithmetic extractors. __istream_type &
operator>> (long long &__n)
Integer arithmetic extractors. __istream_type &
operator>> (unsigned long long &__n)
Integer arithmetic extractors.
__istream_type & operator>> (float &__f)
Floating point arithmetic extractors. __istream_type &
operator>> (double &__f)
Floating point arithmetic extractors. __istream_type &
operator>> (long double &__f)
Floating point arithmetic extractors.
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 ()
Simple extraction. __istream_type & get (char_type &__c)
Simple extraction. __istream_type & get (char_type *__s,
streamsize __n, char_type __delim)
Simple multiple-character extraction. __istream_type & get
(char_type *__s, streamsize __n)
Simple multiple-character extraction. __istream_type & get
(__streambuf_type &__sb, char_type __delim)
Extraction into another streambuf. __istream_type & get
(__streambuf_type &__sb)
Extraction into another streambuf. __istream_type & getline
(char_type *__s, streamsize __n, char_type __delim)
String extraction. __istream_type & getline (char_type *__s,
streamsize __n)
String extraction. __istream_type & ignore
(streamsize __n, int_type __delim)
Discarding characters. __istream_type & ignore
(streamsize __n)
Simple extraction. __istream_type & ignore ()
Simple extraction. int_type peek ()
Looking ahead in the stream. __istream_type & read
(char_type *__s, streamsize __n)
Extraction without delimiters. streamsize readsome (char_type
*__s, streamsize __n)
Extraction until the buffer is exhausted, but no more. __istream_type
& putback (char_type __c)
Unextracting a single character. __istream_type & unget ()
Unextracting the previous character. int sync ()
Synchronizing the stream buffer. pos_type tellg ()
Getting the current read position. __istream_type & seekg
(pos_type)
Changing the current read position. __istream_type & seekg
(off_type, ios_base::seekdir)
Changing the current read position.
operator bool () const
The quick-and-easy status check. bool operator! () const
The quick-and-easy status check.
Static Public Member Functions¶
static bool sync_with_stdio (bool __sync=true)
Interaction with the standard C I/O objects. static int xalloc () throw
()
Access to unique indices.
Static Public Attributes¶
static const fmtflags adjustfield
A mask of left|right|internal. Useful for the 2-arg form of setf.
static const openmode app
Seek to end before each write. static const openmode ate
Open and seek to end immediately after opening. static const iostate
badbit
Indicates a loss of integrity in an input or output sequence (such as an
irrecoverable read error from a file). static const fmtflags
basefield
A mask of dec|oct|hex. Useful for the 2-arg form of setf. static const
seekdir beg
Request a seek relative to the beginning of the stream. static const
openmode binary
Perform input and output in binary mode (as opposed to text mode). This is
probably not what you think it is; see
https://gcc.gnu.org/onlinedocs/libstdc++/manual/fstreams.html#std.io.filestreams.binary.
static const fmtflags boolalpha
Insert/extract bool in alphabetic rather than numeric format. static
const seekdir cur
Request a seek relative to the current position within the sequence. static
const fmtflags dec
Converts integer input or generates integer output in decimal base. static
const seekdir end
Request a seek relative to the current end of the sequence. static const
iostate eofbit
Indicates that an input operation reached the end of an input sequence. static
const iostate failbit
Indicates that an input operation failed to read the expected characters, or
that an output operation failed to generate the desired characters. static
const fmtflags fixed
Generate floating-point output in fixed-point notation. static const
fmtflags floatfield
A mask of scientific|fixed. Useful for the 2-arg form of setf. static
const iostate goodbit
Indicates all is well. static const fmtflags hex
Converts integer input or generates integer output in hexadecimal base. static
const openmode in
Open for input. Default for ifstream and fstream. static const
fmtflags internal
Adds fill characters at a designated internal point in certain generated
output, or identical to right if no such point is designated. static
const fmtflags left
Adds fill characters on the right (final positions) of certain generated
output. (I.e., the thing you print is flush left.) static const
fmtflags oct
Converts integer input or generates integer output in octal base. static const
openmode out
Open for output. Default for ofstream and fstream. static const
fmtflags right
Adds fill characters on the left (initial positions) of certain generated
output. (I.e., the thing you print is flush right.) static const
fmtflags scientific
Generates floating-point output in scientific notation. static const
fmtflags showbase
Generates a prefix indicating the numeric base of generated integer output.
static const fmtflags showpoint
Generates a decimal-point character unconditionally in generated
floating-point output. static const fmtflags showpos
Generates a + sign in non-negative generated numeric output. static const
fmtflags skipws
Skips leading white space before certain input operations. static const
openmode trunc
Truncate an existing stream when opening. Default for ofstream. static
const fmtflags unitbuf
Flushes output after each output operation. static const fmtflags
uppercase
Replaces certain lowercase letters with their uppercase equivalents in
generated output.
Protected Types¶
enum { _S_local_word_size }
Protected Member Functions¶
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)
All setup is performed here. 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
_Traits Traits 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¶
template<typename _CharT , typename _Traits > typedef ctype<_CharT> std::basic_istream< _CharT, _Traits >::__ctype_type [inherited]¶
Definition at line 74 of file istream.
template<typename _CharT , typename _Traits > typedef basic_filebuf<char_type, traits_type> std::basic_ifstream< _CharT, _Traits >::__filebuf_type¶
Definition at line 508 of file fstream.
template<typename _CharT , typename _Traits > typedef basic_ios<_CharT, _Traits> std::basic_istream< _CharT, _Traits >::__ios_type [inherited]¶
Definition at line 70 of file istream.
template<typename _CharT , typename _Traits > typedef basic_istream<char_type, traits_type> std::basic_ifstream< _CharT, _Traits >::__istream_type¶
Definition at line 509 of file fstream.
template<typename _CharT , typename _Traits > typedef num_get<_CharT, istreambuf_iterator<_CharT, _Traits> > std::basic_istream< _CharT, _Traits >::__num_get_type [inherited]¶
Definition at line 73 of file istream.
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.
template<typename _CharT , typename _Traits > typedef basic_streambuf<_CharT, _Traits> std::basic_istream< _CharT, _Traits >::__streambuf_type [inherited]¶
Definition at line 69 of file istream.
template<typename _CharT , typename _Traits > typedef _CharT std::basic_ifstream< _CharT, _Traits >::char_type¶
Definition at line 501 of file fstream.
typedef void(* std::ios_base::event_callback) (event __e, ios_base &__b, int __i) [inherited]¶
The type of an event callback function.
Parameters
__b Reference to the ios_base object.
__i The integer provided when the callback was registered.
Event callbacks are user defined functions that get called during several ios_base and basic_ios functions, specifically imbue(), copyfmt(), and ~ios().
Definition at line 529 of file ios_base.h.
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.
template<typename _CharT , typename _Traits > typedef traits_type::int_type std::basic_ifstream< _CharT, _Traits >::int_type¶
Definition at line 503 of file fstream.
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.
template<typename _CharT , typename _Traits > typedef traits_type::off_type std::basic_ifstream< _CharT, _Traits >::off_type¶
Definition at line 505 of file fstream.
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.
template<typename _CharT , typename _Traits > typedef traits_type::pos_type std::basic_ifstream< _CharT, _Traits >::pos_type¶
Definition at line 504 of file fstream.
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.
template<typename _CharT , typename _Traits > typedef _Traits std::basic_ifstream< _CharT, _Traits >::traits_type¶
Definition at line 502 of file fstream.
Member Enumeration Documentation¶
anonymous enum [protected], [inherited]¶
Definition at line 604 of file ios_base.h.
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¶
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.
template<typename _CharT , typename _Traits > std::basic_ifstream< _CharT, _Traits >::basic_ifstream (const char * __s, ios_base::openmode __mode = ios_base::in) [inline], [explicit]¶
Create an input file stream.
Parameters
__mode Open file in specified mode (see std::ios_base).
ios_base::in is automatically included in __mode.
Definition at line 534 of file fstream.
template<typename _CharT , typename _Traits > std::basic_ifstream< _CharT, _Traits >::basic_ifstream (const std::string & __s, ios_base::openmode __mode = ios_base::in) [inline], [explicit]¶
Create an input file stream.
Parameters
__mode Open file in specified mode (see std::ios_base).
ios_base::in is automatically included in __mode.
Definition at line 567 of file fstream.
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
__mode Open file in specified mode (see std::ios_base).
ios_base::in is automatically included in __mode.
Definition at line 584 of file fstream.
template<typename _CharT , typename _Traits > std::basic_ifstream< _CharT, _Traits >::basic_ifstream (basic_ifstream< _CharT, _Traits > && __rhs) [inline]¶
Definition at line 592 of file fstream.
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¶
template<typename _CharT , typename _Traits > void std::basic_ios< _CharT, _Traits >::_M_cache_locale (const locale & __loc) [protected], [inherited]¶
Definition at line 157 of file basic_ios.tcc.
template<typename _CharT , typename _Traits > template<typename _ValueT > basic_istream< _CharT, _Traits > & std::basic_istream< _CharT, _Traits >::_M_extract (_ValueT & __v) [inherited]¶
Definition at line 94 of file istream.tcc.
const locale & std::ios_base::_M_getloc () const [inline], [inherited]¶
Locale access.
Returns
Like getloc above, but returns a reference instead of generating a copy.
Definition at line 804 of file ios_base.h.
Referenced by std::money_get< _CharT, _InIter >::do_get(), std::time_get< _CharT, _InIter >::do_get(), std::num_get< _CharT, _InIter >::do_get(), std::time_get< _CharT, _InIter >::do_get_date(), std::time_get< _CharT, _InIter >::do_get_monthname(), std::time_get< _CharT, _InIter >::do_get_time(), std::time_get< _CharT, _InIter >::do_get_weekday(), std::num_put< _CharT, _OutIter >::do_put(), std::time_put< _CharT, _OutIter >::do_put(), std::time_get< _CharT, _InIter >::get(), and std::time_put< _CharT, _OutIter >::put().
template<typename _CharT , typename _Traits > void std::basic_ios< _CharT, _Traits >::_M_setstate (iostate __state) [inline], [inherited]¶
Definition at line 164 of file basic_ios.h.
template<typename _CharT , typename _Traits > bool std::basic_ios< _CharT, _Traits >::bad () const [inline], [inherited]¶
Fast error checking.
Returns
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().
template<typename _CharT , typename _Traits > void std::basic_ios< _CharT, _Traits >::clear (iostate __state = goodbit) [inherited]¶
[Re]sets the error state.
Parameters
See std::ios_base::iostate for the possible bit values. Most users will not need to pass an argument.
Definition at line 41 of file basic_ios.tcc.
Referenced by std::basic_ios< _CharT, _Traits >::exceptions(), std::__detail::operator>>(), 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().
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.
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
Returns
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::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().
template<typename _CharT , typename _Traits > bool std::basic_ios< _CharT, _Traits >::eof () const [inline], [inherited]¶
Fast error checking.
Returns
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().
template<typename _CharT , typename _Traits > iostate std::basic_ios< _CharT, _Traits >::exceptions () const [inline], [inherited]¶
Throwing exceptions on errors.
Returns
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().
template<typename _CharT , typename _Traits > void std::basic_ios< _CharT, _Traits >::exceptions (iostate __except) [inline], [inherited]¶
Throwing exceptions on errors.
Parameters
By default, error flags are set silently. You can set an exceptions mask for each stream; if a bit in the mask becomes set in the error flags, then an exception of type std::ios_base::failure is thrown.
If the error flag is already set when the exceptions mask is added, the exception is immediately thrown. Try running the following under GCC 3.1 or later:
#include <iostream> #include <fstream> #include <exception> int main() {
std::set_terminate (__gnu_cxx::__verbose_terminate_handler);
std::ifstream f ("/etc/motd");
std::cerr << "Setting badbit0;
f.setstate (std::ios_base::badbit);
std::cerr << "Setting exception mask0;
f.exceptions (std::ios_base::badbit); }
Definition at line 257 of file basic_ios.h.
References std::basic_ios< _CharT, _Traits >::clear().
template<typename _CharT , typename _Traits > bool std::basic_ios< _CharT, _Traits >::fail () const [inline], [inherited]¶
Fast error checking.
Returns
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(), and std::basic_ios< _CharT, _Traits >::operator!().
template<typename _CharT , typename _Traits > char_type std::basic_ios< _CharT, _Traits >::fill () const [inline], [inherited]¶
Retrieves the empty character.
Returns
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(), std::basic_ios< _CharT, _Traits >::fill(), and std::gamma_distribution< result_type >::operator()().
template<typename _CharT , typename _Traits > char_type std::basic_ios< _CharT, _Traits >::fill (char_type __ch) [inline], [inherited]¶
Sets a new empty character.
Parameters
Returns
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().
fmtflags std::ios_base::flags () const [inline], [inherited]¶
Access to format flags.
Returns
Definition at line 649 of file ios_base.h.
Referenced by std::basic_ios< _CharT, _Traits >::copyfmt(), std::num_get< _CharT, _InIter >::do_get(), std::num_put< _CharT, _OutIter >::do_put(), std::gamma_distribution< result_type >::operator()(), std::operator<<(), std::operator>>(), and std::__detail::operator>>().
fmtflags std::ios_base::flags (fmtflags __fmtfl) [inline], [inherited]¶
Setting new format flags all at once.
Parameters
Returns
This function overwrites all the format flags with __fmtfl.
Definition at line 660 of file ios_base.h.
template<typename _CharT , typename _Traits > streamsize std::basic_istream< _CharT, _Traits >::gcount () const [inline], [inherited]¶
Character counting.
Returns
Definition at line 269 of file istream.
template<typename _CharT , typename _Traits > basic_istream< _CharT, _Traits >::int_type std::basic_istream< _CharT, _Traits >::get (void) [inherited]¶
Simple extraction.
Returns
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.
template<typename _CharT , typename _Traits > __istream_type & std::basic_istream< _CharT, _Traits >::get (__streambuf_type & __sb) [inline], [inherited]¶
Extraction into another streambuf.
Parameters
Returns
Returns get(__sb,widen('\n')).
Definition at line 387 of file istream.
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
__delim A 'stop' character.
Returns
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.
template<typename _CharT , typename _Traits > basic_istream< _CharT, _Traits > & std::basic_istream< _CharT, _Traits >::get (char_type & __c) [inherited]¶
Simple extraction.
Parameters
Returns
Tries to extract a character and store it in __c. If none are available, sets failbit and returns traits::eof().
Note
Definition at line 279 of file istream.tcc.
References std::basic_istream< _CharT, _Traits >::_M_gcount, and std::ios_base::goodbit.
template<typename _CharT , typename _Traits > __istream_type & std::basic_istream< _CharT, _Traits >::get (char_type * __s, streamsize __n) [inline], [inherited]¶
Simple multiple-character extraction.
Parameters
__n Maximum number of characters to store in s.
Returns
Returns get(__s,__n,widen('\n')).
Definition at line 354 of file istream.
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
__n Maximum number of characters to store in __s.
__delim A 'stop' character.
Returns
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
Definition at line 316 of file istream.tcc.
References std::basic_istream< _CharT, _Traits >::_M_gcount, and std::ios_base::goodbit.
template<typename _CharT , typename _Traits > __istream_type & std::basic_istream< _CharT, _Traits >::getline (char_type * __s, streamsize __n) [inline], [inherited]¶
String extraction.
Parameters
__n Maximum number of characters to extract.
Returns
Returns getline(__s,__n,widen('\n')).
Definition at line 427 of file istream.
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
__n Maximum number of characters to extract.
__delim A 'stop' character.
Returns
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.
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.
locale std::ios_base::getloc () const [inline], [inherited]¶
Locale access.
Returns
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(), std::money_put< _CharT, _OutIter >::do_put(), and std::ws().
template<typename _CharT , typename _Traits > bool std::basic_ios< _CharT, _Traits >::good () const [inline], [inherited]¶
Fast error checking.
Returns
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>>().
template<typename _CharT , typename _Traits > basic_istream< _CharT, _Traits > & std::basic_istream< _CharT, _Traits >::ignore (void) [inherited]¶
Simple extraction.
Returns
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.
template<typename _CharT , typename _Traits > basic_istream< _CharT, _Traits > & std::basic_istream< _CharT, _Traits >::ignore (streamsize __n) [inherited]¶
Simple extraction.
Returns
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.
template<typename _CharT , typename _Traits > basic_istream< _CharT, _Traits > & std::basic_istream< _CharT, _Traits >::ignore (streamsize __n, int_type __delim) [inherited]¶
Discarding characters.
Parameters
__delim A 'stop' character.
Returns
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.
template<typename _CharT , typename _Traits > locale std::basic_ios< _CharT, _Traits >::imbue (const locale & __loc) [inherited]¶
Moves to a new locale.
Parameters
Returns
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().
template<typename _CharT , typename _Traits > void std::basic_ios< _CharT, _Traits >::init (basic_streambuf< _CharT, _Traits > * __sb) [protected], [inherited]¶
All setup is performed here. This is called from the public constructor. It is not virtual and cannot be redefined.
Definition at line 126 of file basic_ios.tcc.
Referenced by std::basic_ios< _CharT, _Traits >::basic_ios().
template<typename _CharT , typename _Traits > bool std::basic_ifstream< _CharT, _Traits >::is_open () [inline]¶
Wrapper to test for an open file.
Returns
Definition at line 645 of file fstream.
template<typename _CharT , typename _Traits > bool std::basic_ifstream< _CharT, _Traits >::is_open () const [inline]¶
Definition at line 651 of file fstream.
long & std::ios_base::iword (int __ix) [inline], [inherited]¶
Access to integer array.
Parameters
Returns
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.
template<typename _CharT , typename _Traits > void std::basic_ios< _CharT, _Traits >::move (basic_ios< _CharT, _Traits > && __rhs) [inline], [protected], [inherited]¶
Definition at line 490 of file basic_ios.h.
template<typename _CharT , typename _Traits > void std::basic_ios< _CharT, _Traits >::move (basic_ios< _CharT, _Traits > & __rhs) [inline], [protected], [inherited]¶
Definition at line 479 of file basic_ios.h.
template<typename _CharT , typename _Traits > char std::basic_ios< _CharT, _Traits >::narrow (char_type __c, char __dfault) const [inline], [inherited]¶
Squeezes characters.
Parameters
__dfault The character to narrow.
Returns
Maps a character of char_type to a character of char, if possible.
Returns the result of
std::use_facet<ctype<char_type> >(getloc()).narrow(c,dfault)
Additional l10n notes are at http://gcc.gnu.org/onlinedocs/libstdc++/manual/localization.html
Definition at line 430 of file basic_ios.h.
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
__mode The 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.
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
__mode The 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.
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
__mode The 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.
template<typename _CharT , typename _Traits > std::basic_ios< _CharT, _Traits >::operator bool () const [inline], [explicit], [inherited]¶
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().
template<typename _CharT , typename _Traits > bool std::basic_ios< _CharT, _Traits >::operator! () const [inline], [inherited]¶
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().
template<typename _CharT , typename _Traits > basic_ifstream & std::basic_ifstream< _CharT, _Traits >::operator= (basic_ifstream< _CharT, _Traits > && __rhs) [inline]¶
Definition at line 614 of file fstream.
template<typename _CharT , typename _Traits > __istream_type & std::basic_istream< _CharT, _Traits >::operator>> (__ios_type &(*)(__ios_type &) __pf) [inline], [inherited]¶
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.
template<typename _CharT , typename _Traits > __istream_type & std::basic_istream< _CharT, _Traits >::operator>> (__istream_type &(*)(__istream_type &) __pf) [inline], [inherited]¶
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.
template<typename _CharT , typename _Traits > basic_istream< _CharT, _Traits > & std::basic_istream< _CharT, _Traits >::operator>> (__streambuf_type * __sb) [inherited]¶
Extracting into another streambuf.
Parameters
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.
template<typename _CharT , typename _Traits > __istream_type & std::basic_istream< _CharT, _Traits >::operator>> (bool & __n) [inline], [inherited]¶
Integer arithmetic extractors.
Parameters
Returns
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.
template<typename _CharT , typename _Traits > __istream_type & std::basic_istream< _CharT, _Traits >::operator>> (double & __f) [inline], [inherited]¶
Floating point arithmetic extractors.
Parameters
Returns
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.
template<typename _CharT , typename _Traits > __istream_type & std::basic_istream< _CharT, _Traits >::operator>> (float & __f) [inline], [inherited]¶
Floating point arithmetic extractors.
Parameters
Returns
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.
template<typename _CharT , typename _Traits > basic_istream< _CharT, _Traits > & std::basic_istream< _CharT, _Traits >::operator>> (int & __n) [inherited]¶
Integer arithmetic extractors.
Parameters
Returns
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.
template<typename _CharT , typename _Traits > __istream_type & std::basic_istream< _CharT, _Traits >::operator>> (ios_base &(*)(ios_base &) __pf) [inline], [inherited]¶
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.
template<typename _CharT , typename _Traits > __istream_type & std::basic_istream< _CharT, _Traits >::operator>> (long & __n) [inline], [inherited]¶
Integer arithmetic extractors.
Parameters
Returns
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.
template<typename _CharT , typename _Traits > __istream_type & std::basic_istream< _CharT, _Traits >::operator>> (long double & __f) [inline], [inherited]¶
Floating point arithmetic extractors.
Parameters
Returns
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.
template<typename _CharT , typename _Traits > __istream_type & std::basic_istream< _CharT, _Traits >::operator>> (long long & __n) [inline], [inherited]¶
Integer arithmetic extractors.
Parameters
Returns
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.
template<typename _CharT , typename _Traits > basic_istream< _CharT, _Traits > & std::basic_istream< _CharT, _Traits >::operator>> (short & __n) [inherited]¶
Integer arithmetic extractors.
Parameters
Returns
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.
template<typename _CharT , typename _Traits > __istream_type & std::basic_istream< _CharT, _Traits >::operator>> (unsigned int & __n) [inline], [inherited]¶
Integer arithmetic extractors.
Parameters
Returns
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.
template<typename _CharT , typename _Traits > __istream_type & std::basic_istream< _CharT, _Traits >::operator>> (unsigned long & __n) [inline], [inherited]¶
Integer arithmetic extractors.
Parameters
Returns
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.
template<typename _CharT , typename _Traits > __istream_type & std::basic_istream< _CharT, _Traits >::operator>> (unsigned long long & __n) [inline], [inherited]¶
Integer arithmetic extractors.
Parameters
Returns
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.
template<typename _CharT , typename _Traits > __istream_type & std::basic_istream< _CharT, _Traits >::operator>> (unsigned short & __n) [inline], [inherited]¶
Integer arithmetic extractors.
Parameters
Returns
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.
template<typename _CharT , typename _Traits > __istream_type & std::basic_istream< _CharT, _Traits >::operator>> (void *& __p) [inline], [inherited]¶
Basic arithmetic extractors.
Parameters
Returns
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.
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
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.
streamsize std::ios_base::precision () const [inline], [inherited]¶
Flags access.
Returns
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(), and std::gamma_distribution< result_type >::operator()().
streamsize std::ios_base::precision (streamsize __prec) [inline], [inherited]¶
Changing flags.
Parameters
Returns
Definition at line 728 of file ios_base.h.
template<typename _CharT , typename _Traits > basic_istream< _CharT, _Traits > & std::basic_istream< _CharT, _Traits >::putback (char_type __c) [inherited]¶
Unextracting a single character.
Parameters
Returns
If rdbuf() is not null, calls rdbuf()->sputbackc(c).
If rdbuf() is null or if sputbackc() fails, sets badbit in the error state.
Note
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().
void *& std::ios_base::pword (int __ix) [inline], [inherited]¶
Access to void pointer array.
Parameters
Returns
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.
template<typename _CharT , typename _Traits > __filebuf_type * std::basic_ifstream< _CharT, _Traits >::rdbuf () const [inline]¶
Accessing the underlying buffer.
Returns
This hides both signatures of std::basic_ios::rdbuf().
Definition at line 637 of file fstream.
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
Returns
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>
Definition at line 53 of file basic_ios.tcc.
template<typename _CharT , typename _Traits > iostate std::basic_ios< _CharT, _Traits >::rdstate () const [inline], [inherited]¶
Returns the error state of the stream buffer.
Returns
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().
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
__n Maximum number of characters to store.
Returns
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
Definition at line 684 of file istream.tcc.
References std::basic_istream< _CharT, _Traits >::_M_gcount, and std::ios_base::goodbit.
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
__n Maximum number of characters to store.
Returns
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.
void std::ios_base::register_callback (event_callback __fn, int __index) [inherited]¶
Add the callback __fn with parameter __index.
Parameters
__index The integer to pass to the function when invoked.
Registers a function as an event callback with an integer parameter to be passed to the function when invoked. Multiple copies of the function are allowed. If there are multiple callbacks, they are invoked in the order they were registered.
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
__dir The direction in which to seek.
Returns
If fail() is not true, calls rdbuf()->pubseekoff(__off,__dir). If that function fails, sets failbit.
Note
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().
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
Returns
If fail() is not true, calls rdbuf()->pubseekpos(__pos). If that function fails, sets failbit.
Note
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().
template<typename _CharT , typename _Traits > void std::basic_ios< _CharT, _Traits >::set_rdbuf (basic_streambuf< _CharT, _Traits > * __sb) [inline], [protected], [inherited]¶
Definition at line 505 of file basic_ios.h.
fmtflags std::ios_base::setf (fmtflags __fmtfl) [inline], [inherited]¶
Setting new format flags.
Parameters
Returns
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>>().
fmtflags std::ios_base::setf (fmtflags __fmtfl, fmtflags __mask) [inline], [inherited]¶
Setting new format flags.
Parameters
__mask The flags mask for fmtfl.
Returns
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.
template<typename _CharT , typename _Traits > void std::basic_ios< _CharT, _Traits >::setstate (iostate __state) [inline], [inherited]¶
Sets additional flags in the error state.
Parameters
See std::ios_base::iostate for the possible bit values.
Definition at line 157 of file basic_ios.h.
References std::basic_ios< _CharT, _Traits >::clear(), and std::basic_ios< _CharT, _Traits >::rdstate().
Referenced by std::basic_ostream< _CharT, _Traits >::sentry::sentry(), and std::ws().
template<typename _CharT , typename _Traits > void std::basic_ifstream< _CharT, _Traits >::swap (basic_ifstream< _CharT, _Traits > & __rhs) [inline]¶
Definition at line 622 of file fstream.
template<typename _CharT , typename _Traits > void std::basic_ios< _CharT, _Traits >::swap (basic_ios< _CharT, _Traits > & __rhs) [inline], [protected], [noexcept], [inherited]¶
Definition at line 494 of file basic_ios.h.
template<typename _CharT , typename _Traits > void std::basic_istream< _CharT, _Traits >::swap (basic_istream< _CharT, _Traits > & __rhs) [inline], [protected], [inherited]¶
Definition at line 632 of file istream.
template<typename _CharT , typename _Traits > int std::basic_istream< _CharT, _Traits >::sync (void) [inherited]¶
Synchronizing the stream buffer.
Returns
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
Definition at line 815 of file istream.tcc.
References std::ios_base::goodbit.
static bool std::ios_base::sync_with_stdio (bool __sync = true) [static], [inherited]¶
Interaction with the standard C I/O objects.
Parameters
Returns
The synchronization referred to is only that between the standard C facilities (e.g., stdout) and the standard C++ objects (e.g., cout). User-declared streams are unaffected. See https://gcc.gnu.org/onlinedocs/libstdc++/manual/fstreams.html#std.io.filestreams.binary
template<typename _CharT , typename _Traits > basic_istream< _CharT, _Traits >::pos_type std::basic_istream< _CharT, _Traits >::tellg (void) [inherited]¶
Getting the current read position.
Returns
If fail() is not false, returns pos_type(-1) to indicate failure. Otherwise returns rdbuf()->pubseekoff(0,cur,in).
Note
Definition at line 851 of file istream.tcc.
template<typename _CharT , typename _Traits > basic_ostream< _CharT, _Traits > * std::basic_ios< _CharT, _Traits >::tie () const [inline], [inherited]¶
Fetches the current tied stream.
Returns
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().
template<typename _CharT , typename _Traits > basic_ostream< _CharT, _Traits > * std::basic_ios< _CharT, _Traits >::tie (basic_ostream< _CharT, _Traits > * __tiestr) [inline], [inherited]¶
Ties this stream to an output stream.
Parameters
Returns
This sets up a new tie; see tie() for more.
Definition at line 307 of file basic_ios.h.
template<typename _CharT , typename _Traits > basic_istream< _CharT, _Traits > & std::basic_istream< _CharT, _Traits >::unget (void) [inherited]¶
Unextracting the previous character.
Returns
If rdbuf() is not null, calls rdbuf()->sungetc(c).
If rdbuf() is null or if sungetc() fails, sets badbit in the error state.
Note
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>>().
void std::ios_base::unsetf (fmtflags __mask) [inline], [inherited]¶
Clearing format flags.
Parameters
This function clears __mask in the format flags.
Definition at line 708 of file ios_base.h.
template<typename _CharT , typename _Traits > char_type std::basic_ios< _CharT, _Traits >::widen (char __c) const [inline], [inherited]¶
Widens characters.
Parameters
Returns
Maps a character of char to a character of char_type.
Returns the result of
std::use_facet<ctype<char_type> >(getloc()).widen(c)
Additional l10n notes are at http://gcc.gnu.org/onlinedocs/libstdc++/manual/localization.html
Definition at line 449 of file basic_ios.h.
Referenced by std::basic_ios< _CharT, _Traits >::fill(), std::getline(), std::gamma_distribution< result_type >::operator()(), and std::tr2::operator>>().
streamsize std::ios_base::width () const [inline], [inherited]¶
Flags access.
Returns
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().
streamsize std::ios_base::width (streamsize __wide) [inline], [inherited]¶
Changing flags.
Parameters
Returns
Definition at line 751 of file ios_base.h.
static int std::ios_base::xalloc () [static], [inherited]¶
Access to unique indices.
Returns
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¶
_Callback_list* std::ios_base::_M_callbacks [protected], [inherited]¶
Definition at line 583 of file ios_base.h.
template<typename _CharT , typename _Traits > const __ctype_type* std::basic_ios< _CharT, _Traits >::_M_ctype [protected], [inherited]¶
Definition at line 102 of file basic_ios.h.
iostate std::ios_base::_M_exception [protected], [inherited]¶
Definition at line 548 of file ios_base.h.
template<typename _CharT , typename _Traits > char_type std::basic_ios< _CharT, _Traits >::_M_fill [mutable], [protected], [inherited]¶
Definition at line 97 of file basic_ios.h.
template<typename _CharT , typename _Traits > bool std::basic_ios< _CharT, _Traits >::_M_fill_init [mutable], [protected], [inherited]¶
Definition at line 98 of file basic_ios.h.
fmtflags std::ios_base::_M_flags [protected], [inherited]¶
Definition at line 547 of file ios_base.h.
template<typename _CharT , typename _Traits > streamsize std::basic_istream< _CharT, _Traits >::_M_gcount [protected], [inherited]¶
The number of characters extracted in the previous unformatted function; see gcount().
Definition at line 82 of file istream.
Referenced by std::basic_istream< char >::sentry::sentry(), std::basic_istream< _CharT, _Traits >::get(), std::basic_istream< char >::getline(), std::basic_istream< _CharT, _Traits >::ignore(), std::basic_istream< _CharT, _Traits >::peek(), std::basic_istream< _CharT, _Traits >::putback(), std::basic_istream< char >::putback(), std::basic_istream< _CharT, _Traits >::read(), std::basic_istream< _CharT, _Traits >::readsome(), std::basic_istream< char >::seekg(), std::basic_istream< _CharT, _Traits >::unget(), and std::basic_istream< char >::unget().
locale std::ios_base::_M_ios_locale [protected], [inherited]¶
Definition at line 615 of file ios_base.h.
_Words std::ios_base::_M_local_word[_S_local_word_size] [protected], [inherited]¶
Definition at line 605 of file ios_base.h.
template<typename _CharT , typename _Traits > const __num_get_type* std::basic_ios< _CharT, _Traits >::_M_num_get [protected], [inherited]¶
Definition at line 106 of file basic_ios.h.
template<typename _CharT , typename _Traits > const __num_put_type* std::basic_ios< _CharT, _Traits >::_M_num_put [protected], [inherited]¶
Definition at line 104 of file basic_ios.h.
streamsize std::ios_base::_M_precision [protected], [inherited]¶
Definition at line 545 of file ios_base.h.
template<typename _CharT , typename _Traits > basic_streambuf<_CharT, _Traits>* std::basic_ios< _CharT, _Traits >::_M_streambuf [protected], [inherited]¶
Definition at line 99 of file basic_ios.h.
iostate std::ios_base::_M_streambuf_state [protected], [inherited]¶
Definition at line 549 of file ios_base.h.
template<typename _CharT , typename _Traits > basic_ostream<_CharT, _Traits>* std::basic_ios< _CharT, _Traits >::_M_tie [protected], [inherited]¶
Definition at line 96 of file basic_ios.h.
streamsize std::ios_base::_M_width [protected], [inherited]¶
Definition at line 546 of file ios_base.h.
_Words* std::ios_base::_M_word [protected], [inherited]¶
Definition at line 609 of file ios_base.h.
int std::ios_base::_M_word_size [protected], [inherited]¶
Definition at line 608 of file ios_base.h.
_Words std::ios_base::_M_word_zero [protected], [inherited]¶
Definition at line 600 of file ios_base.h.
const fmtflags std::ios_base::adjustfield [static], [inherited]¶
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().
const openmode std::ios_base::app [static], [inherited]¶
Seek to end before each write.
Definition at line 450 of file ios_base.h.
Referenced by std::basic_filebuf< _CharT, _Traits >::overflow(), and std::basic_filebuf< _CharT, _Traits >::xsputn().
const openmode std::ios_base::ate [static], [inherited]¶
Open and seek to end immediately after opening.
Definition at line 453 of file ios_base.h.
Referenced by std::basic_filebuf< _CharT, _Traits >::open().
const iostate std::ios_base::badbit [static], [inherited]¶
Indicates a loss of integrity in an input or output sequence (such as an irrecoverable read error from a file).
Definition at line 420 of file ios_base.h.
Referenced by std::basic_ios< _CharT, _Traits >::bad(), std::basic_ios< _CharT, _Traits >::fail(), std::basic_istream< char >::get(), and std::basic_istream< char >::ignore().
const fmtflags std::ios_base::basefield [static], [inherited]¶
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().
const seekdir std::ios_base::beg [static], [inherited]¶
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().
const openmode std::ios_base::binary [static], [inherited]¶
Perform input and output in binary mode (as opposed to text mode). This is probably not what you think it is; see https://gcc.gnu.org/onlinedocs/libstdc++/manual/fstreams.html#std.io.filestreams.binary.
Definition at line 458 of file ios_base.h.
Referenced by std::basic_filebuf< _CharT, _Traits >::showmanyc().
const fmtflags std::ios_base::boolalpha [static], [inherited]¶
Insert/extract bool in alphabetic rather than numeric format.
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().
const seekdir std::ios_base::cur [static], [inherited]¶
Request a seek relative to the current position within the sequence.
Definition at line 485 of file ios_base.h.
Referenced by std::basic_filebuf< _CharT, _Traits >::imbue(), std::basic_filebuf< _CharT, _Traits >::overflow(), std::basic_filebuf< _CharT, _Traits >::pbackfail(), std::basic_filebuf< _CharT, _Traits >::seekoff(), and std::basic_stringbuf< _CharT, _Traits, _Alloc >::seekoff().
const fmtflags std::ios_base::dec [static], [inherited]¶
Converts integer input or generates integer output in decimal base.
Definition at line 347 of file ios_base.h.
Referenced by std::dec().
const seekdir std::ios_base::end [static], [inherited]¶
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().
const iostate std::ios_base::eofbit [static], [inherited]¶
Indicates that an input operation reached the end of an input sequence.
Definition at line 423 of file ios_base.h.
Referenced by std::basic_istream< char >::sentry::sentry(), std::time_get< _CharT, _InIter >::do_get(), std::num_get< _CharT, _InIter >::do_get(), std::time_get< _CharT, _InIter >::do_get_date(), std::time_get< _CharT, _InIter >::do_get_monthname(), std::time_get< _CharT, _InIter >::do_get_time(), std::time_get< _CharT, _InIter >::do_get_weekday(), std::time_get< _CharT, _InIter >::do_get_year(), std::basic_ios< _CharT, _Traits >::eof(), std::time_get< _CharT, _InIter >::get(), std::basic_istream< _CharT, _Traits >::putback(), std::basic_istream< _CharT, _Traits >::seekg(), std::basic_istream< char >::sync(), std::basic_istream< _CharT, _Traits >::unget(), and std::ws().
const iostate std::ios_base::failbit [static], [inherited]¶
Indicates that an input operation failed to read the expected characters, or that an output operation failed to generate the desired characters.
Definition at line 428 of file ios_base.h.
Referenced by std::basic_ostream< _CharT, _Traits >::sentry::sentry(), std::num_get< _CharT, _InIter >::do_get(), std::time_get< _CharT, _InIter >::do_get_monthname(), std::time_get< _CharT, _InIter >::do_get_weekday(), std::time_get< _CharT, _InIter >::do_get_year(), std::basic_ios< _CharT, _Traits >::fail(), std::time_get< _CharT, _InIter >::get(), and std::basic_istream< char >::operator>>().
const fmtflags std::ios_base::fixed [static], [inherited]¶
Generate floating-point output in fixed-point notation.
Definition at line 350 of file ios_base.h.
Referenced by std::fixed(), and std::hexfloat().
const fmtflags std::ios_base::floatfield [static], [inherited]¶
A mask of scientific|fixed. Useful for the 2-arg form of setf.
Definition at line 402 of file ios_base.h.
Referenced by std::defaultfloat(), std::fixed(), std::hexfloat(), and std::scientific().
const iostate std::ios_base::goodbit [static], [inherited]¶
Indicates all is well.
Definition at line 431 of file ios_base.h.
Referenced by std::basic_istream< _CharT, _Traits >::sentry::sentry(), std::time_get< _CharT, _InIter >::do_get(), std::num_get< _CharT, _InIter >::do_get(), std::time_get< _CharT, _InIter >::do_get_monthname(), std::time_get< _CharT, _InIter >::do_get_weekday(), std::time_get< _CharT, _InIter >::do_get_year(), std::basic_ostream< _CharT, _Traits >::flush(), std::basic_istream< _CharT, _Traits >::get(), std::time_get< _CharT, _InIter >::get(), std::basic_istream< char >::getline(), std::basic_istream< _CharT, _Traits >::ignore(), std::basic_ostream< _CharT, _Traits >::operator<<(), std::operator>>(), std::basic_istream< _CharT, _Traits >::operator>>(), std::basic_istream< char >::operator>>(), std::basic_istream< _CharT, _Traits >::peek(), std::basic_ostream< _CharT, _Traits >::put(), std::basic_istream< _CharT, _Traits >::putback(), std::basic_istream< _CharT, _Traits >::read(), std::basic_istream< _CharT, _Traits >::readsome(), std::basic_istream< _CharT, _Traits >::seekg(), std::basic_ostream< _CharT, _Traits >::seekp(), std::basic_istream< _CharT, _Traits >::sync(), and std::basic_istream< _CharT, _Traits >::unget().
const fmtflags std::ios_base::hex [static], [inherited]¶
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().
const openmode std::ios_base::in [static], [inherited]¶
Open for input. Default for ifstream and fstream.
Definition at line 461 of file ios_base.h.
Referenced by std::basic_stringbuf< _CharT, _Traits, _Alloc >::overflow(), std::basic_filebuf< _CharT, _Traits >::pbackfail(), std::basic_stringbuf< _CharT, _Traits, _Alloc >::seekoff(), std::basic_stringbuf< _CharT, _Traits, _Alloc >::seekpos(), std::basic_filebuf< _CharT, _Traits >::showmanyc(), std::basic_filebuf< _CharT, _Traits >::underflow(), std::basic_stringbuf< _CharT, _Traits, _Alloc >::underflow(), and std::basic_filebuf< _CharT, _Traits >::xsgetn().
const fmtflags std::ios_base::internal [static], [inherited]¶
Adds fill characters at a designated internal point in certain generated output, or identical to right if no such point is designated.
Definition at line 358 of file ios_base.h.
Referenced by std::internal().
const fmtflags std::ios_base::left [static], [inherited]¶
Adds fill characters on the right (final positions) of certain generated output. (I.e., the thing you print is flush left.)
Definition at line 362 of file ios_base.h.
Referenced by std::num_put< _CharT, _OutIter >::do_put(), and std::left().
const fmtflags std::ios_base::oct [static], [inherited]¶
Converts integer input or generates integer output in octal base.
Definition at line 365 of file ios_base.h.
Referenced by std::oct().
const openmode std::ios_base::out [static], [inherited]¶
Open for output. Default for ofstream and fstream.
Definition at line 464 of file ios_base.h.
Referenced by std::basic_filebuf< _CharT, _Traits >::overflow(), std::basic_stringbuf< _CharT, _Traits, _Alloc >::overflow(), std::basic_stringbuf< _CharT, _Traits, _Alloc >::pbackfail(), std::basic_stringbuf< _CharT, _Traits, _Alloc >::seekoff(), std::basic_stringbuf< _CharT, _Traits, _Alloc >::seekpos(), and std::basic_filebuf< _CharT, _Traits >::xsputn().
const fmtflags std::ios_base::right [static], [inherited]¶
Adds fill characters on the left (initial positions) of certain generated output. (I.e., the thing you print is flush right.)
Definition at line 369 of file ios_base.h.
Referenced by std::right().
const fmtflags std::ios_base::scientific [static], [inherited]¶
Generates floating-point output in scientific notation.
Definition at line 372 of file ios_base.h.
Referenced by std::hexfloat(), and std::scientific().
const fmtflags std::ios_base::showbase [static], [inherited]¶
Generates a prefix indicating the numeric base of generated integer output.
Definition at line 376 of file ios_base.h.
Referenced by std::num_put< _CharT, _OutIter >::do_put(), std::noshowbase(), and std::showbase().
const fmtflags std::ios_base::showpoint [static], [inherited]¶
Generates a decimal-point character unconditionally in generated floating-point output.
Definition at line 380 of file ios_base.h.
Referenced by std::noshowpoint(), and std::showpoint().
const fmtflags std::ios_base::showpos [static], [inherited]¶
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().
const fmtflags std::ios_base::skipws [static], [inherited]¶
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().
const openmode std::ios_base::trunc [static], [inherited]¶
Truncate an existing stream when opening. Default for ofstream.
Definition at line 467 of file ios_base.h.
const fmtflags std::ios_base::unitbuf [static], [inherited]¶
Flushes output after each output operation.
Definition at line 389 of file ios_base.h.
Referenced by std::nounitbuf(), and std::unitbuf().
const fmtflags std::ios_base::uppercase [static], [inherited]¶
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().
Author¶
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