NAME¶

std::ios_base -

SYNOPSIS¶

Inherited by std::basic_ios< _CharT, _Traits >.

Classes¶

class failure

Public Types¶

enum event { erase_event, imbue_event, copyfmt_event } typedef void(* event_callback )(event __e, ios_base &__b, int __i) typedef _Ios_Fmtflags fmtflags typedef int io_state typedef _Ios_Iostate iostate typedef int open_mode typedef _Ios_Openmode openmode typedef int seek_dir typedef _Ios_Seekdir seekdir typedef std::streamoff streamoff typedef std::streampos streampos

Public Member Functions¶

virtual ~ios_base () const locale & _M_getloc () const fmtflags flags () const fmtflags flags (fmtflags __fmtfl) locale getloc () const locale imbue (const locale &__loc) throw () long & iword (int __ix) streamsize precision () const streamsize precision (streamsize __prec) void *& pword (int __ix) void register_callback (event_callback __fn, int __index) fmtflags setf (fmtflags __fmtfl) fmtflags setf (fmtflags __fmtfl, fmtflags __mask) void unsetf (fmtflags __mask) streamsize width () const streamsize width (streamsize __wide)

Static Public Member Functions¶

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

Static Public Attributes¶

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

Protected Types¶

enum { _S_local_word_size }

Protected Member Functions¶

void _M_call_callbacks (event __ev) throw () void _M_dispose_callbacks (void) throw () _Words & _M_grow_words (int __index, bool __iword) void _M_init () throw ()

Protected Attributes¶

_Callback_list * _M_callbacks iostate _M_exception fmtflags _M_flags locale _M_ios_locale _Words _M_local_word [_S_local_word_size] streamsize _M_precision iostate _M_streambuf_state streamsize _M_width _Words * _M_word int _M_word_size _Words _M_word_zero

Detailed Description¶

The base of the I/O class hierarchy. This class defines everything that can be defined about I/O that does not depend on the type of characters being input or output. Most people will only see ios_base when they need to specify the full name of the various I/O flags (e.g., the openmodes). Definition at line 199 of file ios_base.h.

Member Typedef Documentation¶

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

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 436 of file ios_base.h.

typedef _Ios_Fmtflags std::ios_base::fmtflags¶

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:

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boolalpha

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dec

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fixed

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hex

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internal

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left

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oct

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right

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scientific

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showbase

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showpoint

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showpos

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skipws

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unitbuf

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uppercase

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adjustfield

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basefield

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floatfield

Definition at line 255 of file ios_base.h.

typedef _Ios_Iostate std::ios_base::iostate¶

This is a bitmask type. _Ios_Iostate is implementation-defined, but it is valid to perform bitwise operations on these values and expect the Right Thing to happen. Defined objects of type iostate are:

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badbit

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eofbit

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failbit

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goodbit

Definition at line 330 of file ios_base.h.

typedef _Ios_Openmode std::ios_base::openmode¶

This is a bitmask type. _Ios_Openmode is implementation-defined, but it is valid to perform bitwise operations on these values and expect the Right Thing to happen. Defined objects of type openmode are:

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app

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ate

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binary

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in

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out

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trunc

Definition at line 361 of file ios_base.h.

typedef _Ios_Seekdir std::ios_base::seekdir¶

This is an enumerated type. _Ios_Seekdir is implementation-defined. Defined values of type seekdir are:

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beg

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cur, equivalent to SEEK_CUR in the C standard library.

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end, equivalent to SEEK_END in the C standard library.

Definition at line 393 of file ios_base.h.

Member Enumeration Documentation¶

enum std::ios_base::event¶

The set of events that may be passed to an event callback. erase_event is used during ~ios() and copyfmt(). imbue_event is used during imbue(). copyfmt_event is used during copyfmt(). Definition at line 419 of file ios_base.h.

Constructor & Destructor Documentation¶

virtual std::ios_base::~ios_base () [virtual]¶

Invokes each callback with erase_event. Destroys local storage. Note that the ios_base object for the standard streams never gets destroyed. As a result, any callbacks registered with the standard streams will not get invoked with erase_event (unless copyfmt is used).

Member Function Documentation¶

const locale& std::ios_base::_M_getloc () const [inline]¶

Locale access. Returns: Like getloc above, but returns a reference instead of generating a copy. Definition at line 706 of file ios_base.h.

fmtflags std::ios_base::flags () const [inline]¶

Access to format flags. Returns: Definition at line 551 of file ios_base.h.

fmtflags std::ios_base::flags ( fmtflags__fmtfl) [inline]¶

Setting new format flags all at once. Parameters: Returns: This function overwrites all the format flags with __fmtfl. Definition at line 562 of file ios_base.h.

locale std::ios_base::getloc () const [inline]¶

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 695 of file ios_base.h.

locale std::ios_base::imbue (const locale &__loc)¶

Setting a new locale. Parameters: Returns: Sets the new locale for this stream, and then invokes each callback with imbue_event.

long& std::ios_base::iword (int__ix) [inline]¶

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 741 of file ios_base.h.

streamsize std::ios_base::precision () const [inline]¶

Flags access. Returns: Be careful if you try to give a definition of precision here; see DR 189. Definition at line 621 of file ios_base.h.

streamsize std::ios_base::precision ( streamsize__prec) [inline]¶

Changing flags. Parameters: Returns: Definition at line 630 of file ios_base.h.

void*& std::ios_base::pword (int__ix) [inline]¶

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 762 of file ios_base.h.

void std::ios_base::register_callback ( event_callback__fn, int__index)¶

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.

fmtflags std::ios_base::setf ( fmtflags__fmtfl) [inline]¶

Setting new format flags. Parameters: Returns: This function sets additional flags in format control. Flags that were previously set remain set. Definition at line 578 of file ios_base.h. Referenced by std::boolalpha(), std::dec(), std::fixed(), std::hex(), std::left(), std::oct(), std::right(), std::scientific(), std::showbase(), std::showpoint(), std::showpos(), std::skipws(), std::unitbuf(), and std::uppercase().

fmtflags std::ios_base::setf ( fmtflags__fmtfl, fmtflags__mask) [inline]¶

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 595 of file ios_base.h.

static bool std::ios_base::sync_with_stdio (bool__sync = true) [static]¶

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 http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt11ch28s02.html

void std::ios_base::unsetf ( fmtflags__mask) [inline]¶

Clearing format flags. Parameters: This function clears __mask in the format flags. Definition at line 610 of file ios_base.h. Referenced by std::noboolalpha(), std::noshowbase(), std::noshowpoint(), std::noshowpos(), std::noskipws(), std::nounitbuf(), and std::nouppercase().

streamsize std::ios_base::width () const [inline]¶

Flags access. Returns: Minimum field width refers to the number of characters. Definition at line 644 of file ios_base.h.

streamsize std::ios_base::width ( streamsize__wide) [inline]¶

Changing flags. Parameters: Returns: Definition at line 653 of file ios_base.h.

static int std::ios_base::xalloc () [static]¶

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¶

const fmtflags std::ios_base::adjustfield [static]¶

A mask of left|right|internal. Useful for the 2-arg form of setf. Definition at line 310 of file ios_base.h. Referenced by std::internal(), std::left(), and std::right().

const openmode std::ios_base::app [static]¶

Seek to end before each write. Definition at line 364 of file ios_base.h.

const openmode std::ios_base::ate [static]¶

Open and seek to end immediately after opening. Definition at line 367 of file ios_base.h.

const iostate std::ios_base::badbit [static]¶

Indicates a loss of integrity in an input or output sequence (such as an irrecoverable read error from a file). Definition at line 334 of file ios_base.h. Referenced by std::basic_ios< _CharT, _Traits >::bad(), and std::basic_ios< _CharT, _Traits >::fail().

const fmtflags std::ios_base::basefield [static]¶

A mask of dec|oct|hex. Useful for the 2-arg form of setf. Definition at line 313 of file ios_base.h. Referenced by std::dec(), std::hex(), and std::oct().

const seekdir std::ios_base::beg [static]¶

Request a seek relative to the beginning of the stream. Definition at line 396 of file ios_base.h.

const openmode std::ios_base::binary [static]¶

Perform input and output in binary mode (as opposed to text mode). This is probably not what you think it is; see http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt11ch27s02.html. Definition at line 372 of file ios_base.h.

const fmtflags std::ios_base::boolalpha [static]¶

Insert/extract bool in alphabetic rather than numeric format. Definition at line 258 of file ios_base.h. Referenced by std::boolalpha(), and std::noboolalpha().

const seekdir std::ios_base::cur [static]¶

Request a seek relative to the current position within the sequence. Definition at line 399 of file ios_base.h.

const fmtflags std::ios_base::dec [static]¶

Converts integer input or generates integer output in decimal base. Definition at line 261 of file ios_base.h. Referenced by std::dec().

const seekdir std::ios_base::end [static]¶

Request a seek relative to the current end of the sequence. Definition at line 402 of file ios_base.h.

const iostate std::ios_base::eofbit [static]¶

Indicates that an input operation reached the end of an input sequence. Definition at line 337 of file ios_base.h. Referenced by std::basic_ios< _CharT, _Traits >::eof().

const iostate std::ios_base::failbit [static]¶

Indicates that an input operation failed to read the expected characters, or that an output operation failed to generate the desired characters. Definition at line 342 of file ios_base.h. Referenced by std::basic_ios< _CharT, _Traits >::fail().

const fmtflags std::ios_base::fixed [static]¶

Generate floating-point output in fixed-point notation. Definition at line 264 of file ios_base.h. Referenced by std::fixed().

const fmtflags std::ios_base::floatfield [static]¶

A mask of scientific|fixed. Useful for the 2-arg form of setf. Definition at line 316 of file ios_base.h. Referenced by std::fixed(), and std::scientific().

const iostate std::ios_base::goodbit [static]¶

Indicates all is well. Definition at line 345 of file ios_base.h.

const fmtflags std::ios_base::hex [static]¶

Converts integer input or generates integer output in hexadecimal base. Definition at line 267 of file ios_base.h. Referenced by std::hex().

const openmode std::ios_base::in [static]¶

Open for input. Default for ifstream and fstream. Definition at line 375 of file ios_base.h.

const fmtflags std::ios_base::internal [static]¶

Adds fill characters at a designated internal point in certain generated output, or identical to right if no such point is designated. Definition at line 272 of file ios_base.h. Referenced by std::internal().

const fmtflags std::ios_base::left [static]¶

Adds fill characters on the right (final positions) of certain generated output. (I.e., the thing you print is flush left.) Definition at line 276 of file ios_base.h. Referenced by std::left().

const fmtflags std::ios_base::oct [static]¶

Converts integer input or generates integer output in octal base. Definition at line 279 of file ios_base.h. Referenced by std::oct().

const openmode std::ios_base::out [static]¶

Open for output. Default for ofstream and fstream. Definition at line 378 of file ios_base.h.

const fmtflags std::ios_base::right [static]¶

Adds fill characters on the left (initial positions) of certain generated output. (I.e., the thing you print is flush right.) Definition at line 283 of file ios_base.h. Referenced by std::right().

const fmtflags std::ios_base::scientific [static]¶

Generates floating-point output in scientific notation. Definition at line 286 of file ios_base.h. Referenced by std::scientific().

const fmtflags std::ios_base::showbase [static]¶

Generates a prefix indicating the numeric base of generated integer output. Definition at line 290 of file ios_base.h. Referenced by std::noshowbase(), and std::showbase().

const fmtflags std::ios_base::showpoint [static]¶

Generates a decimal-point character unconditionally in generated floating-point output. Definition at line 294 of file ios_base.h. Referenced by std::noshowpoint(), and std::showpoint().

const fmtflags std::ios_base::showpos [static]¶

Generates a + sign in non-negative generated numeric output. Definition at line 297 of file ios_base.h. Referenced by std::noshowpos(), and std::showpos().

const fmtflags std::ios_base::skipws [static]¶

Skips leading white space before certain input operations. Definition at line 300 of file ios_base.h. Referenced by std::noskipws(), and std::skipws().

const openmode std::ios_base::trunc [static]¶

Open for input. Default for ofstream. Definition at line 381 of file ios_base.h.

const fmtflags std::ios_base::unitbuf [static]¶

Flushes output after each output operation. Definition at line 303 of file ios_base.h. Referenced by std::nounitbuf(), and std::unitbuf().

const fmtflags std::ios_base::uppercase [static]¶

Replaces certain lowercase letters with their uppercase equivalents in generated output. Definition at line 307 of file ios_base.h. Referenced by std::nouppercase(), and std::uppercase().

Author¶

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