Inherits std::basic_istream< _CharT, _Traits >.
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 int io_state
typedef _Ios_Iostate iostate
This is a bitmask type.
typedef traits_type::off_type off_type
typedef int open_mode
typedef _Ios_Openmode openmode
This is a bitmask type.
typedef traits_type::pos_type pos_type
typedef int seek_dir
typedef _Ios_Seekdir seekdir
This is an enumerated type.
typedef std::streamoff streamoff
typedef std::streampos streampos
typedef _Traits traits_type
typedef num_put< _CharT, ostreambuf_iterator< _CharT, _Traits > > __num_put_type
basic_ifstream ()
Default constructor.
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 (const basic_ifstream &)=delete
basic_ifstream (basic_ifstream &&__rhs)
~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.
template<> basic_istream< char > & getline (char_type *__s, streamsize __n, char_type __delim)
Explicit specialization declarations, defined in src/istream.cc.
template<> basic_istream< wchar_t > & getline (char_type *__s, streamsize __n, char_type __delim)
locale getloc () const
Locale access.
bool good () const
Fast error checking.
template<> basic_istream< char > & ignore (streamsize __n)
template<> basic_istream< char > & ignore (streamsize __n, int_type __delim)
template<> basic_istream< wchar_t > & ignore (streamsize __n)
template<> 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.
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= (const basic_ifstream &)=delete
basic_ifstream & operator= (basic_ifstream &&__rhs)
__istream_type & operator>> (void *&__p)
Basic arithmetic extractors.
__istream_type & operator>> (__streambuf_type *__sb)
Extracting into another streambuf.
streamsize precision () const
Flags access.
streamsize precision (streamsize __prec)
Changing flags.
void *& pword (int __ix)
Access to void pointer array.
basic_streambuf< _CharT, _Traits > * rdbuf (basic_streambuf< _CharT, _Traits > *__sb)
Changing the underlying buffer.
__filebuf_type * rdbuf () const
Accessing 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 bool sync_with_stdio (bool __sync=true)
Interaction with the standard C I/O objects.
static int xalloc () throw ()
Access to unique indices.
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
Open for input. 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.
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)
_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
Template Parameters:
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 476 of file fstream.
Definition at line 89 of file basic_ios.h.
The type of an event callback function.
Parameters:
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 506 of file ios_base.h.
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:
Definition at line 323 of file ios_base.h.
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:
Definition at line 398 of file ios_base.h.
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:
Definition at line 429 of file ios_base.h.
This is an enumerated type. _Ios_Seekdir is implementation-defined. Defined values of type seekdir are:
Definition at line 461 of file ios_base.h.
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 489 of file ios_base.h.
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 502 of file fstream.
References std::basic_ios< _CharT, _Traits >::init().
Create an input file stream.
Parameters:
ios_base::in is automatically included in __mode.
Definition at line 513 of file fstream.
References std::basic_ios< _CharT, _Traits >::init(), and std::basic_ifstream< _CharT, _Traits >::open().
Create an input file stream.
Parameters:
ios_base::in is automatically included in __mode.
Definition at line 529 of file fstream.
References std::basic_ios< _CharT, _Traits >::init(), and std::basic_ifstream< _CharT, _Traits >::open().
The destructor does nothing. The file is closed by the filebuf object, not the formatting stream.
Definition at line 566 of file fstream.
Locale access.
Returns:
Like getloc above, but returns a reference instead of generating a copy.
Definition at line 776 of file ios_base.h.
Referenced by std::time_get< _CharT, _InIter >::do_get(), std::money_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_put< _CharT, _OutIter >::do_put(), std::num_put< _CharT, _OutIter >::do_put(), std::time_get< _CharT, _InIter >::get(), and std::time_put< _CharT, _OutIter >::put().
Fast error checking.
Returns:
Note that other iostate flags may also be set.
Definition at line 211 of file basic_ios.h.
[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< char, _Traits >::exceptions(), std::basic_ifstream< _CharT, _Traits >::open(), std::basic_ofstream< _CharT, _Traits >::open(), std::basic_fstream< _CharT, _Traits >::open(), std::__detail::operator>>(), std::basic_istream< char >::putback(), std::basic_istream< char >::seekg(), std::basic_ios< char, _Traits >::setstate(), and std::basic_istream< char >::unget().
Close the file. Calls std::basic_filebuf::close(). If that function fails, failbit is set in the stream's error state.
Definition at line 678 of file fstream.
References std::basic_filebuf< _CharT, _Traits >::close(), std::ios_base::failbit, and std::basic_ios< _CharT, _Traits >::setstate().
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.
Fast error checking.
Returns:
Note that other iostate flags may also be set.
Definition at line 190 of file basic_ios.h.
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< char, _Traits >::copyfmt().
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 badbit;
f.setstate (std::ios_base::badbit);
std::cerr << "Setting exception mask;
f.exceptions (std::ios_base::badbit);
}
Definition at line 257 of file basic_ios.h.
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.
Referenced by std::basic_ios< char, _Traits >::operator bool(), std::basic_ios< char, _Traits >::operator!(), and std::regex_traits< _CharType >::value().
Retrieves the empty character.
Returns:
It defaults to a space (' ') in the current locale.
Definition at line 370 of file basic_ios.h.
Referenced by std::basic_ios< char, _Traits >::copyfmt(), std::basic_ios< char, _Traits >::fill(), and std::operator<<().
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.
Access to format flags.
Returns:
Definition at line 621 of file ios_base.h.
Referenced by std::basic_ios< char, _Traits >::copyfmt(), std::num_get< _CharT, _InIter >::do_get(), std::num_put< _CharT, _OutIter >::do_put(), std::basic_ostream< char >::operator<<(), std::operator<<(), std::__detail::operator>>(), and std::operator>>().
Setting new format flags all at once.
Parameters:
Returns:
This function overwrites all the format flags with __fmtfl.
Definition at line 632 of file ios_base.h.
Character counting.
Returns:
Definition at line 269 of file istream.
Simple extraction.
Returns:
Tries to extract a character. If none are available, sets failbit and returns traits::eof().
Definition at line 244 of file istream.tcc.
Referenced by std::basic_istream< char >::get().
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 280 of file istream.tcc.
Simple multiple-character extraction.
Parameters:
Returns:
Characters are extracted and stored into __s until one of the following happens:
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 317 of file istream.tcc.
Simple multiple-character extraction.
Parameters:
Returns:
Returns get(__s,__n,widen('\n')).
Definition at line 354 of file istream.
Extraction into another streambuf.
Parameters:
Returns:
Characters are extracted and inserted into __sb until one of the following happens:
If no characters are stored, failbit is set in the stream's error state.
Definition at line 364 of file istream.tcc.
Extraction into another streambuf.
Parameters:
Returns:
Returns get(__sb,widen('\n')).
Definition at line 387 of file istream.
String extraction.
Parameters:
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.
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 408 of file istream.tcc.
Referenced by std::basic_istream< char >::getline().
String extraction.
Parameters:
Returns:
Returns getline(__s,__n,widen('\n')).
Definition at line 427 of file istream.
Explicit specialization declarations, defined in src/istream.cc.
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 765 of file ios_base.h.
Referenced by std::basic_ios< char, _Traits >::copyfmt(), std::money_put< _CharT, _OutIter >::do_put(), std::tr2::operator<<(), std::operator<<(), and std::ws().
Fast error checking.
Returns:
A wrapper around rdstate.
Definition at line 180 of file basic_ios.h.
Referenced by std::__detail::operator>>(), std::basic_ostream< _CharT, _Traits >::sentry::sentry(), and std::basic_istream< _CharT, _Traits >::sentry::sentry().
Discarding characters.
Parameters:
Returns:
Extracts characters and throws them away until one of the following happens:
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 563 of file istream.tcc.
Simple extraction.
Returns:
Tries to extract a character. If none are available, sets failbit and returns traits::eof().
Definition at line 501 of file istream.tcc.
Simple extraction.
Returns:
Tries to extract a character. If none are available, sets failbit and returns traits::eof().
Definition at line 468 of file istream.tcc.
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.
Referenced by std::operator<<().
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_fstream< _CharT, _Traits >::basic_fstream(), std::basic_ifstream< _CharT, _Traits >::basic_ifstream(), std::basic_ios< char, _Traits >::basic_ios(), std::basic_istream< char >::basic_istream(), std::basic_istringstream< _CharT, _Traits, _Alloc >::basic_istringstream(), std::basic_ofstream< _CharT, _Traits >::basic_ofstream(), std::basic_ostream< char >::basic_ostream(), std::basic_ostringstream< _CharT, _Traits, _Alloc >::basic_ostringstream(), and std::basic_stringstream< _CharT, _Traits, _Alloc >::basic_stringstream().
Wrapper to test for an open file.
Returns:
Definition at line 607 of file fstream.
References std::basic_filebuf< _CharT, _Traits >::is_open().
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 811 of file ios_base.h.
Squeezes characters.
Parameters:
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.
Opens an external file.
Parameters:
Calls std::basic_filebuf::open(s,__mode|in). If that function fails, failbit is set in the stream's error state.
Definition at line 625 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().
Opens an external file.
Parameters:
Calls std::basic_filebuf::open(__s,__mode|in). If that function fails, failbit is set in the stream's error state.
Definition at line 645 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().
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.
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.
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.
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.
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.
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.
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 122 of file istream.tcc.
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.
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 167 of file istream.tcc.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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:
If the function inserts no characters, failbit is set.
Definition at line 212 of file istream.tcc.
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 628 of file istream.tcc.
Flags access.
Returns:
Be careful if you try to give a definition of precision here; see DR 189.
Definition at line 691 of file ios_base.h.
Referenced by std::basic_ios< char, _Traits >::copyfmt(), and std::operator<<().
Changing flags.
Parameters:
Returns:
Definition at line 700 of file ios_base.h.
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 719 of file istream.tcc.
Referenced by std::operator>>().
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 832 of file ios_base.h.
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.
Accessing the underlying buffer.
Returns:
This hides both signatures of std::basic_ios::rdbuf().
Definition at line 599 of file fstream.
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< char, _Traits >::bad(), std::basic_ios< char, _Traits >::eof(), std::basic_ios< char, _Traits >::fail(), std::basic_ios< char, _Traits >::good(), std::basic_istream< char >::putback(), std::basic_istream< char >::seekg(), std::basic_ios< char, _Traits >::setstate(), and std::basic_istream< char >::unget().
Extraction without delimiters.
Parameters:
Returns:
If the stream state is good(), extracts characters and stores them into __s until one of the following happens:
Note:
Definition at line 658 of file istream.tcc.
Extraction until the buffer is exhausted, but no more.
Parameters:
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:
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 687 of file istream.tcc.
Add the callback __fn with parameter __index.
Parameters:
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.
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 853 of file istream.tcc.
Changing the current read position.
Parameters:
Returns:
If fail() is not true, calls rdbuf()->pubseekoff(__off,__dir). If that function fails, sets failbit.
Note:
Definition at line 892 of file istream.tcc.
Setting new format flags.
Parameters:
Returns:
This function sets additional flags in format control. Flags that were previously set remain set.
Definition at line 648 of file ios_base.h.
Referenced by std::__detail::operator>>().
Setting new format flags.
Parameters:
Returns:
This function clears mask in the format flags, then sets fmtfl & mask. An example mask is ios_base::adjustfield.
Definition at line 665 of file ios_base.h.
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.
Referenced by std::basic_ostream< char >::_M_write(), std::basic_ifstream< _CharT, _Traits >::close(), std::basic_ofstream< _CharT, _Traits >::close(), std::basic_fstream< _CharT, _Traits >::close(), std::basic_ifstream< _CharT, _Traits >::open(), std::basic_ofstream< _CharT, _Traits >::open(), std::basic_fstream< _CharT, _Traits >::open(), std::operator<<(), std::operator>>(), std::basic_ostream< _CharT, _Traits >::sentry::sentry(), and std::ws().
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 789 of file istream.tcc.
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
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 825 of file istream.tcc.
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_ios< char, _Traits >::copyfmt(), and std::basic_ostream< _CharT, _Traits >::sentry::sentry().
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.
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 754 of file istream.tcc.
Referenced by std::__detail::operator>>().
Clearing format flags.
Parameters:
This function clears __mask in the format flags.
Definition at line 680 of file ios_base.h.
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< char, _Traits >::fill(), std::basic_istream< char >::get(), std::basic_istream< char >::getline(), std::getline(), std::operator<<(), std::tr2::operator>>(), and std::operator>>().
Flags access.
Returns:
Minimum field width refers to the number of characters.
Definition at line 714 of file ios_base.h.
Referenced by std::basic_ios< char, _Traits >::copyfmt(), and std::num_put< _CharT, _OutIter >::do_put().
Changing flags.
Parameters:
Returns:
Definition at line 723 of file ios_base.h.
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.
Definition at line 82 of file istream.
Referenced by std::basic_istream< char >::gcount(), std::basic_istream< char >::get(), std::basic_istream< char >::getline(), std::basic_istream< char >::ignore(), std::basic_istream< char >::peek(), std::basic_istream< char >::putback(), std::basic_istream< char >::read(), std::basic_istream< char >::readsome(), std::basic_istream< char >::unget(), and std::basic_istream< char >::~basic_istream().
A mask of left|right|internal. Useful for the 2-arg form of setf.
Definition at line 378 of file ios_base.h.
Referenced by std::num_put< _CharT, _OutIter >::do_put().
Seek to end before each write.
Definition at line 432 of file ios_base.h.
Referenced by std::basic_filebuf< char_type, traits_type >::_M_set_buffer().
Open and seek to end immediately after opening.
Definition at line 435 of file ios_base.h.
Indicates a loss of integrity in an input or output sequence (such as an irrecoverable read error from a file).
Definition at line 402 of file ios_base.h.
Referenced by std::basic_ostream< char >::_M_write(), std::basic_ios< char, _Traits >::bad(), std::basic_ios< char, _Traits >::fail(), std::operator<<(), and std::basic_ostream< _CharT, _Traits >::sentry::~sentry().
A mask of dec|oct|hex. Useful for the 2-arg form of setf.
Definition at line 381 of file ios_base.h.
Referenced by std::num_get< _CharT, _InIter >::do_get(), std::num_put< _CharT, _OutIter >::do_put(), and std::basic_ostream< char >::operator<<().
Request a seek relative to the beginning of the stream.
Definition at line 464 of file ios_base.h.
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 440 of file ios_base.h.
Insert/extract bool in alphabetic rather than numeric format.
Definition at line 326 of file ios_base.h.
Referenced by std::num_get< _CharT, _InIter >::do_get(), and std::num_put< _CharT, _OutIter >::do_put().
Request a seek relative to the current position within the sequence.
Definition at line 467 of file ios_base.h.
Referenced by std::basic_stringbuf< _CharT, _Traits, _Alloc >::seekoff().
Converts integer input or generates integer output in decimal base.
Definition at line 329 of file ios_base.h.
Request a seek relative to the current end of the sequence.
Definition at line 470 of file ios_base.h.
Referenced by std::basic_stringbuf< _CharT, _Traits, _Alloc >::seekoff().
Indicates that an input operation reached the end of an input sequence.
Definition at line 405 of file ios_base.h.
Referenced by 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< char, _Traits >::eof(), std::time_get< _CharT, _InIter >::get(), std::basic_istream< char >::putback(), std::basic_istream< char >::seekg(), std::basic_istream< char >::unget(), and std::ws().
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 410 of file ios_base.h.
Referenced by std::basic_ifstream< _CharT, _Traits >::close(), std::basic_ofstream< _CharT, _Traits >::close(), std::basic_fstream< _CharT, _Traits >::close(), std::num_get< _CharT, _InIter >::do_get(), std::time_get< _CharT, _InIter >::do_get_monthname(), std::time_get< _CharT, _InIter >::do_get_weekday(), std::time_get< _CharT, _InIter >::do_get_year(), std::basic_ios< char, _Traits >::fail(), std::time_get< _CharT, _InIter >::get(), std::basic_ifstream< _CharT, _Traits >::open(), std::basic_ofstream< _CharT, _Traits >::open(), std::basic_fstream< _CharT, _Traits >::open(), std::operator>>(), and std::basic_ostream< _CharT, _Traits >::sentry::sentry().
Generate floating-point output in fixed-point notation.
Definition at line 332 of file ios_base.h.
A mask of scientific|fixed. Useful for the 2-arg form of setf.
Definition at line 384 of file ios_base.h.
Indicates all is well.
Definition at line 413 of file ios_base.h.
Referenced by 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< char >::flush(), std::basic_istream< char >::get(), std::time_get< _CharT, _InIter >::get(), std::basic_istream< char >::getline(), std::basic_istream< char >::ignore(), std::basic_ostream< char >::operator<<(), std::basic_istream< char >::operator>>(), std::operator>>(), std::basic_istream< char >::peek(), std::basic_ostream< char >::put(), std::basic_istream< char >::putback(), std::basic_istream< char >::read(), std::basic_istream< char >::readsome(), std::basic_istream< char >::seekg(), std::basic_ostream< char >::seekp(), std::basic_istream< _CharT, _Traits >::sentry::sentry(), std::basic_istream< char >::sync(), and std::basic_istream< char >::unget().
Converts integer input or generates integer output in hexadecimal base.
Definition at line 335 of file ios_base.h.
Referenced by std::num_get< _CharT, _InIter >::do_get(), std::num_put< _CharT, _OutIter >::do_put(), and std::basic_ostream< char >::operator<<().
Open for input. Default for ifstream and fstream.
Definition at line 443 of file ios_base.h.
Referenced by std::basic_filebuf< char_type, traits_type >::_M_set_buffer(), std::basic_ifstream< _CharT, _Traits >::open(), std::basic_stringbuf< _CharT, _Traits, _Alloc >::seekoff(), std::basic_stringbuf< _CharT, _Traits, _Alloc >::seekpos(), std::basic_stringbuf< _CharT, _Traits, _Alloc >::showmanyc(), and std::basic_stringbuf< _CharT, _Traits, _Alloc >::underflow().
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 340 of file ios_base.h.
Adds fill characters on the right (final positions) of certain generated output. (I.e., the thing you print is flush left.)
Definition at line 344 of file ios_base.h.
Referenced by std::num_put< _CharT, _OutIter >::do_put().
Converts integer input or generates integer output in octal base.
Definition at line 347 of file ios_base.h.
Referenced by std::basic_ostream< char >::operator<<().
Open for output. Default for ofstream and fstream.
Definition at line 446 of file ios_base.h.
Referenced by std::basic_filebuf< char_type, traits_type >::_M_set_buffer(), std::basic_ofstream< _CharT, _Traits >::open(), std::basic_stringbuf< _CharT, _Traits, _Alloc >::seekoff(), and std::basic_stringbuf< _CharT, _Traits, _Alloc >::seekpos().
Adds fill characters on the left (initial positions) of certain generated output. (I.e., the thing you print is flush right.)
Definition at line 351 of file ios_base.h.
Generates floating-point output in scientific notation.
Definition at line 354 of file ios_base.h.
Generates a prefix indicating the numeric base of generated integer output.
Definition at line 358 of file ios_base.h.
Referenced by std::num_put< _CharT, _OutIter >::do_put().
Generates a decimal-point character unconditionally in generated floating-point output.
Definition at line 362 of file ios_base.h.
Generates a + sign in non-negative generated numeric output.
Definition at line 365 of file ios_base.h.
Skips leading white space before certain input operations.
Definition at line 368 of file ios_base.h.
Open for input. Default for ofstream.
Definition at line 449 of file ios_base.h.
Flushes output after each output operation.
Definition at line 371 of file ios_base.h.
Referenced by std::basic_ostream< _CharT, _Traits >::sentry::~sentry().
Replaces certain lowercase letters with their uppercase equivalents in generated output.
Definition at line 375 of file ios_base.h.
Referenced by std::num_put< _CharT, _OutIter >::do_put().
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