std::basic_stringstream< _CharT, _Traits, _Alloc >(3cxx) | std::basic_stringstream< _CharT, _Traits, _Alloc >(3cxx) |
NAME¶
std::basic_stringstream< _CharT, _Traits, _Alloc > - Controlling input and output for std::string.
SYNOPSIS¶
Inherits std::basic_iostream< _CharT, _Traits >.
Public Types¶
typedef ctype< _CharT > __ctype_type
typedef ctype< _CharT > __ctype_type
typedef basic_ios< _CharT, _Traits > __ios_type
typedef basic_ios< _CharT, _Traits > __ios_type
typedef basic_iostream< char_type, traits_type >
__iostream_type
typedef basic_istream< _CharT, _Traits > __istream_type
typedef num_get< _CharT, istreambuf_iterator< _CharT,
_Traits > > __num_get_type
typedef num_put< _CharT, ostreambuf_iterator< _CharT,
_Traits > > __num_put_type
typedef basic_ostream< _CharT, _Traits > __ostream_type
typedef basic_streambuf< _CharT, _Traits >
__streambuf_type
typedef basic_streambuf< _CharT, _Traits >
__streambuf_type
typedef basic_string< _CharT, _Traits, _Alloc >
__string_type
typedef basic_stringbuf< _CharT, _Traits, _Alloc >
__stringbuf_type
typedef _Alloc allocator_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
Public Member Functions¶
basic_stringstream (ios_base::openmode
__m=ios_base::out|ios_base::in)
Default constructor starts with an empty string buffer.
basic_stringstream (const __string_type &__str,
ios_base::openmode __m=ios_base::out|ios_base::in)
Starts with an existing string buffer. basic_stringstream (const
basic_stringstream &)=delete
basic_stringstream (basic_stringstream &&__rhs)
~basic_stringstream ()
The destructor does nothing. template<typename _ValueT >
basic_istream< _CharT, _Traits > & _M_extract
(_ValueT &__v)
const locale & _M_getloc () const
Locale access. template<typename _ValueT > basic_ostream<
_CharT, _Traits > & _M_insert (_ValueT __v)
void _M_setstate (iostate __state)
bool bad () const
Fast error checking. void clear (iostate __state=goodbit)
[Re]sets the error state. basic_ios & copyfmt (const
basic_ios &__rhs)
Copies fields of __rhs into this. bool eof () const
Fast error checking. iostate exceptions () const
Throwing exceptions on errors. void exceptions (iostate
__except)
Throwing exceptions on errors. bool fail () const
Fast error checking. char_type fill () const
Retrieves the empty character. char_type fill (char_type __ch)
Sets a new empty character. fmtflags flags () const
Access to format flags. fmtflags flags (fmtflags __fmtfl)
Setting new format flags all at once. __ostream_type & flush
()
Synchronizing the stream buffer. 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. long & iword (int __ix)
Access to integer array. char narrow (char_type __c, char __dfault)
const
Squeezes characters. __ostream_type & operator<<
(const void *__p)
Pointer arithmetic inserters. __ostream_type &
operator<< (__streambuf_type *__sb)
Extracting from another streambuf. basic_stringstream &
operator= (const basic_stringstream &)=delete
basic_stringstream & operator= (basic_stringstream
&&__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. __stringbuf_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. __ostream_type &
seekp (pos_type)
Changing the current write position. __ostream_type & seekp
(off_type, ios_base::seekdir)
Changing the current write position. 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. __string_type str ()
const
Copying out the string buffer. void str (const __string_type
&__s)
Setting a new buffer. void swap (basic_stringstream &__rhs)
pos_type tellp ()
Getting the current write position. 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. The original exception will then be rethrown.
__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. The original exception will then be rethrown.
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.
__ostream_type & operator<< (__ostream_type
&(*__pf)(__ostream_type &))
Interface for manipulators. __ostream_type &
operator<< (__ios_type &(*__pf)(__ios_type
&))
Interface for manipulators. __ostream_type &
operator<< (ios_base &(*__pf)(ios_base
&))
Interface for manipulators.
Inserters
All the operator<< functions (aka formatted output
functions) have some common behavior. Each starts by constructing a
temporary object of type std::basic_ostream::sentry. This can have several
effects, concluding with the setting of a status flag; see the sentry
documentation for more.
If the sentry status is good, the function tries to generate whatever data is appropriate for the type of the argument.
If an exception is thrown during insertion, ios_base::badbit will be turned on in the stream's error state without causing an ios_base::failure to be thrown. The original exception will then be rethrown.
__ostream_type & operator<< (long __n)
Integer arithmetic inserters. __ostream_type &
operator<< (unsigned long __n)
Integer arithmetic inserters. __ostream_type &
operator<< (bool __n)
Integer arithmetic inserters. __ostream_type &
operator<< (short __n)
Integer arithmetic inserters. __ostream_type &
operator<< (unsigned short __n)
Integer arithmetic inserters. __ostream_type &
operator<< (int __n)
Integer arithmetic inserters. __ostream_type &
operator<< (unsigned int __n)
Integer arithmetic inserters. __ostream_type &
operator<< (long long __n)
Integer arithmetic inserters. __ostream_type &
operator<< (unsigned long long __n)
Integer arithmetic inserters.
__ostream_type & operator<< (double __f)
Floating point arithmetic inserters. __ostream_type &
operator<< (float __f)
Floating point arithmetic inserters. __ostream_type &
operator<< (long double __f)
Floating point arithmetic inserters.
Unformatted Output Functions
All the unformatted output functions have some common behavior. Each starts by
constructing a temporary object of type std::basic_ostream::sentry. This has
several effects, concluding with the setting of a status flag; see the
sentry documentation for more.
If the sentry status is good, the function tries to generate whatever data is appropriate for the type of the argument.
If an exception is thrown during insertion, ios_base::badbit will be turned on in the stream's error state. If badbit is on in the stream's exceptions mask, the exception will be rethrown without completing its actions.
__ostream_type & put (char_type __c)
Simple insertion. void _M_write (const char_type *__s,
streamsize __n)
Core write functionality, without sentry. __ostream_type &
write (const char_type *__s, streamsize __n)
Character string insertion.
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
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.
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 ()
template<typename _ValueT > __ostream_type & _M_insert
(_ValueT __v)
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_ostream &__rhs)
void swap (basic_ios &__rhs) noexcept
void swap (basic_istream &__rhs)
void swap (basic_iostream &__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, typename _Alloc>¶
class std::basic_stringstream< _CharT, _Traits, _Alloc >" Controlling input and output for std::string.
Template Parameters:
_Traits Traits for character type, defaults to char_traits<_CharT>.
_Alloc Allocator type, defaults to allocator<_CharT>.
This class supports reading from and writing to objects of type std::basic_string, using the inherited functions from std::basic_iostream. To control the associated sequence, an instance of std::basic_stringbuf is used, which this page refers to as sb.
Definition at line 108 of file iosfwd.
Member Typedef Documentation¶
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.
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 504 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 323 of file ios_base.h.
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 398 of file ios_base.h.
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 429 of file ios_base.h.
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 461 of file ios_base.h.
Member Enumeration Documentation¶
enum std::ios_base::event [inherited]¶
The set of events that may be passed to an event callback. erase_event is used during ~ios() and copyfmt(). imbue_event is used during imbue(). copyfmt_event is used during copyfmt().
Definition at line 487 of file ios_base.h.
Constructor & Destructor Documentation¶
template<typename _CharT , typename _Traits , typename _Alloc > std::basic_stringstream< _CharT, _Traits, _Alloc >::basic_stringstream (ios_base::openmode __m = ios_base::out | ios_base::in) [inline], [explicit]¶
Default constructor starts with an empty string buffer.
Parameters:
Initializes sb using the mode from __m, and passes &sb to the base class initializer. Does not allocate any buffer.
That's a lie. We initialize the base class with NULL, because the string class does its own memory management.
Definition at line 690 of file sstream.
template<typename _CharT , typename _Traits , typename _Alloc > std::basic_stringstream< _CharT, _Traits, _Alloc >::basic_stringstream (const __string_type & __str, ios_base::openmode __m = ios_base::out | ios_base::in) [inline], [explicit]¶
Starts with an existing string buffer.
Parameters:
__m Whether the buffer can read, or write, or both.
Initializes sb using __str and __m, and passes &sb to the base class initializer.
That's a lie. We initialize the base class with NULL, because the string class does its own memory management.
Definition at line 706 of file sstream.
template<typename _CharT , typename _Traits , typename _Alloc > std::basic_stringstream< _CharT, _Traits, _Alloc >::~basic_stringstream () [inline]¶
The destructor does nothing. The buffer is deallocated by the stringbuf object, not the formatting stream.
Definition at line 717 of file sstream.
Member Function Documentation¶
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 774 of file ios_base.h.
Referenced by std::time_get< _CharT, _InIter >::do_date_order(), 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_get< _CharT, _InIter >::do_get_year(), 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().
template<typename _CharT, typename _Traits> void std::basic_ostream< _CharT, _Traits >::_M_write (const char_type * __s, streamsize __n) [inline], [inherited]¶
Core write functionality, without sentry.
Parameters:
__n Maximum number of characters to insert.
Definition at line 311 of file ostream.
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.
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< char, _Traits >::exceptions(), std::__detail::operator>>(), std::basic_istream< char >::putback(), std::basic_ios< char, _Traits >::rdstate(), std::basic_istream< char >::seekg(), std::basic_ios< char, _Traits >::setstate(), and std::basic_istream< char >::unget().
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.
Referenced by std::basic_ios< char, _Traits >::rdbuf().
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.
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< char, _Traits >::copyfmt(), and std::basic_ios< char, _Traits >::setstate().
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.
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.
Referenced by std::basic_ios< char, _Traits >::operator bool(), std::basic_ios< char, _Traits >::operator!(), and std::regex_traits< _CharType >::value().
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.
Referenced by std::basic_ios< char, _Traits >::copyfmt(), and std::basic_ios< char, _Traits >::fill().
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.
fmtflags std::ios_base::flags () const [inline], [inherited]¶
Access to format flags.
Returns:
Definition at line 619 of file ios_base.h.
Referenced by std::basic_ios< char, _Traits >::copyfmt(), std::mersenne_twister_engine< uint_fast32_t, 32, 624, 397, 31, 0x9908b0dfUL, 11, 0xffffffffUL, 7, 0x9d2c5680UL, 15, 0xefc60000UL, 18, 1812433253UL >::discard(), std::money_get< _CharT, _InIter >::do_get(), std::num_get< _CharT, _InIter >::do_get(), std::num_put< _CharT, _OutIter >::do_put(), std::subtract_with_carry_engine< _UIntType, __w, __s, __r >::operator()(), std::discard_block_engine< _RandomNumberEngine, __p, __r >::operator()(), std::shuffle_order_engine< _RandomNumberEngine, __k >::operator()(), std::basic_ostream< char >::operator<<(), std::operator<<(), std::__detail::operator>>(), std::operator>>(), std::linear_congruential_engine< _UIntType, __a, __c, __m >::seed(), and std::basic_istream< _CharT, _Traits >::sentry::sentry().
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 630 of file ios_base.h.
template<typename _CharT , typename _Traits > basic_ostream< _CharT, _Traits > & std::basic_ostream< _CharT, _Traits >::flush () [inherited]¶
Synchronizing the stream buffer.
Returns:
If rdbuf() is a null pointer, changes nothing.
Otherwise, calls rdbuf()->pubsync(), and if that returns -1, sets badbit.
Definition at line 211 of file ostream.tcc.
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 236 of file istream.tcc.
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 272 of file istream.tcc.
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 309 of file istream.tcc.
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 (__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 356 of file istream.tcc.
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 >::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 400 of file istream.tcc.
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<> 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 763 of file ios_base.h.
Referenced by std::basic_ios< char, _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.
Referenced by std::__detail::operator>>(), std::basic_ostream< _CharT, _Traits >::sentry::sentry(), and std::basic_istream< _CharT, _Traits >::sentry::sentry().
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 555 of file istream.tcc.
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 493 of file istream.tcc.
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 460 of file istream.tcc.
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.
Referenced by std::basic_ios< char, _Traits >::fill().
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< char, _Traits >::basic_ios().
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 809 of file ios_base.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> 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.
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.
template<typename _CharT, typename _Traits> __ostream_type& std::basic_ostream< _CharT, _Traits >::operator<< (__ostream_type &(*)(__ostream_type &) __pf) [inline], [inherited]¶
Interface for manipulators. Manipulators such as std::endl and std::hex use these functions in constructs like 'std::cout << std::endl'. For more information, see the iomanip header.
Definition at line 108 of file ostream.
Referenced by std::basic_ostream< char >::operator<<().
template<typename _CharT, typename _Traits> __ostream_type& std::basic_ostream< _CharT, _Traits >::operator<< (__ios_type &(*)(__ios_type &) __pf) [inline], [inherited]¶
Interface for manipulators. Manipulators such as std::endl and std::hex use these functions in constructs like 'std::cout << std::endl'. For more information, see the iomanip header.
Definition at line 117 of file ostream.
template<typename _CharT, typename _Traits> __ostream_type& std::basic_ostream< _CharT, _Traits >::operator<< (ios_base &(*)(ios_base &) __pf) [inline], [inherited]¶
Interface for manipulators. Manipulators such as std::endl and std::hex use these functions in constructs like 'std::cout << std::endl'. For more information, see the iomanip header.
Definition at line 127 of file ostream.
template<typename _CharT, typename _Traits> __ostream_type& std::basic_ostream< _CharT, _Traits >::operator<< (long __n) [inline], [inherited]¶
Integer arithmetic inserters.
Parameters:
Returns:
These functions use the stream's current locale (specifically, the num_get facet) to perform numeric formatting.
Definition at line 166 of file ostream.
template<typename _CharT, typename _Traits> __ostream_type& std::basic_ostream< _CharT, _Traits >::operator<< (unsigned long __n) [inline], [inherited]¶
Integer arithmetic inserters.
Parameters:
Returns:
These functions use the stream's current locale (specifically, the num_get facet) to perform numeric formatting.
Definition at line 170 of file ostream.
template<typename _CharT, typename _Traits> __ostream_type& std::basic_ostream< _CharT, _Traits >::operator<< (bool __n) [inline], [inherited]¶
Integer arithmetic inserters.
Parameters:
Returns:
These functions use the stream's current locale (specifically, the num_get facet) to perform numeric formatting.
Definition at line 174 of file ostream.
template<typename _CharT , typename _Traits > basic_ostream< _CharT, _Traits > & std::basic_ostream< _CharT, _Traits >::operator<< (short __n) [inherited]¶
Integer arithmetic inserters.
Parameters:
Returns:
These functions use the stream's current locale (specifically, the num_get facet) to perform numeric formatting.
Definition at line 92 of file ostream.tcc.
template<typename _CharT, typename _Traits> __ostream_type& std::basic_ostream< _CharT, _Traits >::operator<< (unsigned short __n) [inline], [inherited]¶
Integer arithmetic inserters.
Parameters:
Returns:
These functions use the stream's current locale (specifically, the num_get facet) to perform numeric formatting.
Definition at line 181 of file ostream.
template<typename _CharT , typename _Traits > basic_ostream< _CharT, _Traits > & std::basic_ostream< _CharT, _Traits >::operator<< (int __n) [inherited]¶
Integer arithmetic inserters.
Parameters:
Returns:
These functions use the stream's current locale (specifically, the num_get facet) to perform numeric formatting.
Definition at line 106 of file ostream.tcc.
template<typename _CharT, typename _Traits> __ostream_type& std::basic_ostream< _CharT, _Traits >::operator<< (unsigned int __n) [inline], [inherited]¶
Integer arithmetic inserters.
Parameters:
Returns:
These functions use the stream's current locale (specifically, the num_get facet) to perform numeric formatting.
Definition at line 192 of file ostream.
template<typename _CharT, typename _Traits> __ostream_type& std::basic_ostream< _CharT, _Traits >::operator<< (long long __n) [inline], [inherited]¶
Integer arithmetic inserters.
Parameters:
Returns:
These functions use the stream's current locale (specifically, the num_get facet) to perform numeric formatting.
Definition at line 201 of file ostream.
template<typename _CharT, typename _Traits> __ostream_type& std::basic_ostream< _CharT, _Traits >::operator<< (unsigned long long __n) [inline], [inherited]¶
Integer arithmetic inserters.
Parameters:
Returns:
These functions use the stream's current locale (specifically, the num_get facet) to perform numeric formatting.
Definition at line 205 of file ostream.
template<typename _CharT, typename _Traits> __ostream_type& std::basic_ostream< _CharT, _Traits >::operator<< (double __f) [inline], [inherited]¶
Floating point arithmetic inserters.
Parameters:
Returns:
These functions use the stream's current locale (specifically, the num_get facet) to perform numeric formatting.
Definition at line 220 of file ostream.
template<typename _CharT, typename _Traits> __ostream_type& std::basic_ostream< _CharT, _Traits >::operator<< (float __f) [inline], [inherited]¶
Floating point arithmetic inserters.
Parameters:
Returns:
These functions use the stream's current locale (specifically, the num_get facet) to perform numeric formatting.
Definition at line 224 of file ostream.
template<typename _CharT, typename _Traits> __ostream_type& std::basic_ostream< _CharT, _Traits >::operator<< (long double __f) [inline], [inherited]¶
Floating point arithmetic inserters.
Parameters:
Returns:
These functions use the stream's current locale (specifically, the num_get facet) to perform numeric formatting.
Definition at line 232 of file ostream.
template<typename _CharT, typename _Traits> __ostream_type& std::basic_ostream< _CharT, _Traits >::operator<< (const void * __p) [inline], [inherited]¶
Pointer arithmetic inserters.
Parameters:
Returns:
These functions use the stream's current locale (specifically, the num_get facet) to perform numeric formatting.
Definition at line 245 of file ostream.
template<typename _CharT , typename _Traits > basic_ostream< _CharT, _Traits > & std::basic_ostream< _CharT, _Traits >::operator<< (__streambuf_type * __sb) [inherited]¶
Extracting from 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 __sb and inserted into *this until one of the following occurs:
- the input stream reaches end-of-file,
- insertion into the output sequence fails (in this case, the character that would have been inserted is not extracted), or
- an exception occurs while getting a character from __sb, which sets failbit in the error state
If the function inserts no characters, failbit is set.
Definition at line 120 of file ostream.tcc.
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.
Referenced by std::ws().
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>> (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>> (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 > 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 114 of file istream.tcc.
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 > 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 159 of file istream.tcc.
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>> (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>> (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>> (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> __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>> (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> __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>> (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>> (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 > & 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 204 of file istream.tcc.
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 620 of file istream.tcc.
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 689 of file ios_base.h.
Referenced by std::basic_ios< char, _Traits >::copyfmt().
streamsize std::ios_base::precision (streamsize __prec) [inline], [inherited]¶
Changing flags.
Parameters:
Returns:
Definition at line 698 of file ios_base.h.
template<typename _CharT , typename _Traits > basic_ostream< _CharT, _Traits > & std::basic_ostream< _CharT, _Traits >::put (char_type __c) [inherited]¶
Simple insertion.
Parameters:
Returns:
Tries to insert __c.
Note:
Definition at line 149 of file ostream.tcc.
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 711 of file istream.tcc.
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 830 of file ios_base.h.
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 , typename _Alloc > __stringbuf_type* std::basic_stringstream< _CharT, _Traits, _Alloc >::rdbuf () const [inline]¶
Accessing the underlying buffer.
Returns:
This hides both signatures of std::basic_ios::rdbuf().
Definition at line 757 of file sstream.
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< 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().
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 650 of file istream.tcc.
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 679 of file istream.tcc.
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 (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 845 of file istream.tcc.
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 884 of file istream.tcc.
template<typename _CharT , typename _Traits > basic_ostream< _CharT, _Traits > & std::basic_ostream< _CharT, _Traits >::seekp (pos_type __pos) [inherited]¶
Changing the current write position.
Parameters:
Returns:
If fail() is not true, calls rdbuf()->pubseekpos(pos). If that function fails, sets failbit.
Definition at line 258 of file ostream.tcc.
template<typename _CharT , typename _Traits > basic_ostream< _CharT, _Traits > & std::basic_ostream< _CharT, _Traits >::seekp (off_type __off, ios_base::seekdir __dir) [inherited]¶
Changing the current write 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.
Definition at line 290 of file ostream.tcc.
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 646 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 663 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.
Referenced by std::operator<<(), std::basic_ostream< _CharT, _Traits >::sentry::sentry(), std::basic_istream< _CharT, _Traits >::sentry::sentry(), and std::ws().
template<typename _CharT , typename _Traits , typename _Alloc > __string_type std::basic_stringstream< _CharT, _Traits, _Alloc >::str () const [inline]¶
Copying out the string buffer.
Returns:
Definition at line 765 of file sstream.
template<typename _CharT , typename _Traits , typename _Alloc > void std::basic_stringstream< _CharT, _Traits, _Alloc >::str (const __string_type & __s) [inline]¶
Setting a new buffer.
Parameters:
Calls rdbuf()->str(s).
Definition at line 775 of file sstream.
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 781 of file istream.tcc.
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 817 of file istream.tcc.
template<typename _CharT , typename _Traits > basic_ostream< _CharT, _Traits >::pos_type std::basic_ostream< _CharT, _Traits >::tellp () [inherited]¶
Getting the current write position.
Returns:
If fail() is not false, returns pos_type(-1) to indicate failure. Otherwise returns rdbuf()->pubseekoff(0,cur,out).
Definition at line 237 of file ostream.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_ios< char, _Traits >::basic_ios(), std::basic_ios< char, _Traits >::copyfmt(), std::basic_ostream< _CharT, _Traits >::sentry::sentry(), and std::basic_istream< _CharT, _Traits >::sentry::sentry().
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 746 of file istream.tcc.
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 678 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< char, _Traits >::fill(), std::getline(), 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 712 of file ios_base.h.
Referenced by std::basic_ios< char, _Traits >::copyfmt(), std::money_get< _CharT, _InIter >::do_get(), and std::num_put< _CharT, _OutIter >::do_put().
streamsize std::ios_base::width (streamsize __wide) [inline], [inherited]¶
Changing flags.
Parameters:
Returns:
Definition at line 721 of file ios_base.h.
template<typename _CharT , typename _Traits > basic_ostream< _CharT, _Traits > & std::basic_ostream< _CharT, _Traits >::write (const char_type * __s, streamsize __n) [inherited]¶
Character string insertion.
Parameters:
__n Maximum number of characters to insert.
Returns:
Characters are copied from __s and inserted into the stream until one of the following happens:
- __n characters are inserted
- inserting into the output sequence fails (in this case, badbit will be set in the stream's error state)
Note:
Definition at line 183 of file ostream.tcc.
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¶
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 >::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(), and std::basic_istream< char >::unget().
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 378 of file ios_base.h.
Referenced by std::money_get< _CharT, _InIter >::do_get(), and std::num_put< _CharT, _OutIter >::do_put().
const openmode std::ios_base::app [static], [inherited]¶
Seek to end before each write.
Definition at line 432 of file ios_base.h.
const openmode std::ios_base::ate [static], [inherited]¶
Open and seek to end immediately after opening.
Definition at line 435 of file ios_base.h.
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 402 of file ios_base.h.
Referenced by std::basic_ios< char, _Traits >::bad(), std::basic_ios< char, _Traits >::fail(), and std::operator<<().
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 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<<().
const seekdir std::ios_base::beg [static], [inherited]¶
Request a seek relative to the beginning of the stream.
Definition at line 464 of file ios_base.h.
Referenced by __gnu_cxx::stdio_sync_filebuf< _CharT, _Traits >::sync().
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 440 of file ios_base.h.
const fmtflags std::ios_base::boolalpha [static], [inherited]¶
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().
const seekdir std::ios_base::cur [static], [inherited]¶
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(), and __gnu_cxx::stdio_sync_filebuf< _CharT, _Traits >::sync().
const fmtflags std::ios_base::dec [static], [inherited]¶
Converts integer input or generates integer output in decimal base.
Definition at line 329 of file ios_base.h.
const seekdir std::ios_base::end [static], [inherited]¶
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().
const iostate std::ios_base::eofbit [static], [inherited]¶
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< _CharT, _Traits >::sentry::sentry(), std::basic_istream< char >::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 410 of file ios_base.h.
Referenced by std::time_get< _CharT, _InIter >::do_date_order(), 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_ostream< _CharT, _Traits >::sentry::sentry(), and std::basic_istream< _CharT, _Traits >::sentry::sentry().
const fmtflags std::ios_base::fixed [static], [inherited]¶
Generate floating-point output in fixed-point notation.
Definition at line 332 of file ios_base.h.
const fmtflags std::ios_base::floatfield [static], [inherited]¶
A mask of scientific|fixed. Useful for the 2-arg form of setf.
Definition at line 384 of file ios_base.h.
const iostate std::ios_base::goodbit [static], [inherited]¶
Indicates all is well.
Definition at line 413 of file ios_base.h.
Referenced by std::time_get< _CharT, _InIter >::do_date_order(), 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_ios< char, _Traits >::rdstate(), std::basic_istream< char >::read(), std::basic_istream< char >::readsome(), std::basic_istream< char >::seekg(), std::basic_ostream< char >::seekp(), std::basic_ostream< _CharT, _Traits >::sentry::sentry(), std::basic_istream< _CharT, _Traits >::sentry::sentry(), std::basic_istream< char >::sync(), and std::basic_istream< char >::unget().
const fmtflags std::ios_base::hex [static], [inherited]¶
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<<().
const openmode std::ios_base::in [static], [inherited]¶
Open for input. Default for ifstream and fstream.
Definition at line 443 of file ios_base.h.
Referenced by std::basic_stringbuf< _CharT, _Traits, _Alloc >::seekoff(), std::basic_stringbuf< _CharT, _Traits, _Alloc >::seekpos(), __gnu_cxx::stdio_sync_filebuf< _CharT, _Traits >::sync(), and std::basic_stringbuf< _CharT, _Traits, _Alloc >::underflow().
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 340 of file ios_base.h.
Referenced by std::money_get< _CharT, _InIter >::do_get().
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 344 of file ios_base.h.
Referenced by std::money_get< _CharT, _InIter >::do_get(), and std::num_put< _CharT, _OutIter >::do_put().
const fmtflags std::ios_base::oct [static], [inherited]¶
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<<().
const openmode std::ios_base::out [static], [inherited]¶
Open for output. Default for ofstream and fstream.
Definition at line 446 of file ios_base.h.
Referenced by 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 __gnu_cxx::stdio_sync_filebuf< _CharT, _Traits >::sync().
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 351 of file ios_base.h.
const fmtflags std::ios_base::scientific [static], [inherited]¶
Generates floating-point output in scientific notation.
Definition at line 354 of file ios_base.h.
const fmtflags std::ios_base::showbase [static], [inherited]¶
Generates a prefix indicating the numeric base of generated integer output.
Definition at line 358 of file ios_base.h.
Referenced by std::money_get< _CharT, _InIter >::do_get(), and std::num_put< _CharT, _OutIter >::do_put().
const fmtflags std::ios_base::showpoint [static], [inherited]¶
Generates a decimal-point character unconditionally in generated floating-point output.
Definition at line 362 of file ios_base.h.
const fmtflags std::ios_base::showpos [static], [inherited]¶
Generates a + sign in non-negative generated numeric output.
Definition at line 365 of file ios_base.h.
const fmtflags std::ios_base::skipws [static], [inherited]¶
Skips leading white space before certain input operations.
Definition at line 368 of file ios_base.h.
Referenced by std::basic_istream< _CharT, _Traits >::sentry::sentry().
const openmode std::ios_base::trunc [static], [inherited]¶
Open for input. Default for ofstream.
Definition at line 449 of file ios_base.h.
const fmtflags std::ios_base::unitbuf [static], [inherited]¶
Flushes output after each output operation.
Definition at line 371 of file ios_base.h.
const fmtflags std::ios_base::uppercase [static], [inherited]¶
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().
Author¶
Generated automatically by Doxygen for libstdc++ from the source code.
Mon May 22 2017 | libstdc++ |