ios_base.h
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// Iostreams base classes -*- C++ -*-
// Copyright (C) 1997-2025 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.
// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
// <http://www.gnu.org/licenses/>.
/** @file bits/ios_base.h
* This is an internal header file, included by other library headers.
* Do not attempt to use it directly. @headername{ios}
*/
//
// ISO C++ 14882: 27.4 Iostreams base classes
//
#ifndef _IOS_BASE_H
#define _IOS_BASE_H 1
#ifdef _GLIBCXX_SYSHDR
#pragma GCC system_header
#endif
#include <ext/atomicity.h>
#include <bits/localefwd.h>
#include <bits/locale_classes.h>
#if __cplusplus < 201103L
# include <stdexcept>
#else
# include <system_error>
#endif
namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
// The following definitions of bitmask types are enums, not ints,
// as permitted (but not required) in the standard, in order to provide
// better type safety in iostream calls. A side effect is that in C++98
// expressions involving them are not compile-time constants.
enum _Ios_Fmtflags
{
_S_boolalpha = 1L << 0,
_S_dec = 1L << 1,
_S_fixed = 1L << 2,
_S_hex = 1L << 3,
_S_internal = 1L << 4,
_S_left = 1L << 5,
_S_oct = 1L << 6,
_S_right = 1L << 7,
_S_scientific = 1L << 8,
_S_showbase = 1L << 9,
_S_showpoint = 1L << 10,
_S_showpos = 1L << 11,
_S_skipws = 1L << 12,
_S_unitbuf = 1L << 13,
_S_uppercase = 1L << 14,
_S_adjustfield = _S_left | _S_right | _S_internal,
_S_basefield = _S_dec | _S_oct | _S_hex,
_S_floatfield = _S_scientific | _S_fixed,
_S_ios_fmtflags_end = 1L << 16,
_S_ios_fmtflags_max = __INT_MAX__,
_S_ios_fmtflags_min = ~__INT_MAX__
};
_GLIBCXX_NODISCARD _GLIBCXX_CONSTEXPR
inline _Ios_Fmtflags
operator&(_Ios_Fmtflags __a, _Ios_Fmtflags __b) _GLIBCXX_NOTHROW
{ return _Ios_Fmtflags(static_cast<int>(__a) & static_cast<int>(__b)); }
_GLIBCXX_NODISCARD _GLIBCXX_CONSTEXPR
inline _Ios_Fmtflags
operator|(_Ios_Fmtflags __a, _Ios_Fmtflags __b) _GLIBCXX_NOTHROW
{ return _Ios_Fmtflags(static_cast<int>(__a) | static_cast<int>(__b)); }
_GLIBCXX_NODISCARD _GLIBCXX_CONSTEXPR
inline _Ios_Fmtflags
operator^(_Ios_Fmtflags __a, _Ios_Fmtflags __b) _GLIBCXX_NOTHROW
{ return _Ios_Fmtflags(static_cast<int>(__a) ^ static_cast<int>(__b)); }
_GLIBCXX_NODISCARD _GLIBCXX_CONSTEXPR
inline _Ios_Fmtflags
operator~(_Ios_Fmtflags __a) _GLIBCXX_NOTHROW
{ return _Ios_Fmtflags(~static_cast<int>(__a)); }
_GLIBCXX14_CONSTEXPR
inline const _Ios_Fmtflags&
operator|=(_Ios_Fmtflags& __a, _Ios_Fmtflags __b) _GLIBCXX_NOTHROW
{ return __a = __a | __b; }
_GLIBCXX14_CONSTEXPR
inline const _Ios_Fmtflags&
operator&=(_Ios_Fmtflags& __a, _Ios_Fmtflags __b) _GLIBCXX_NOTHROW
{ return __a = __a & __b; }
_GLIBCXX14_CONSTEXPR
inline const _Ios_Fmtflags&
operator^=(_Ios_Fmtflags& __a, _Ios_Fmtflags __b) _GLIBCXX_NOTHROW
{ return __a = __a ^ __b; }
// If std::ios_base::noreplace isn't available, -Wswitch should ignore
// _S_noreplace.
#ifdef __glibcxx_ios_noreplace
#define _NOREPLACE_UNUSED
#else
#define _NOREPLACE_UNUSED __attribute__((__unused__))
#endif
enum __attribute__((__flag_enum__)) _Ios_Openmode
{
_S_app = 1L << 0,
_S_ate = 1L << 1,
_S_bin = 1L << 2,
_S_in = 1L << 3,
_S_out = 1L << 4,
_S_trunc = 1L << 5,
_S_noreplace _NOREPLACE_UNUSED = 1L << 6,
_S_ios_openmode_end __attribute__((__unused__)) = 1L << 16,
_S_ios_openmode_max __attribute__((__unused__)) = __INT_MAX__,
_S_ios_openmode_min __attribute__((__unused__)) = ~__INT_MAX__
};
#undef _NOREPLACE_UNUSED
_GLIBCXX_NODISCARD _GLIBCXX_CONSTEXPR
inline _Ios_Openmode
operator&(_Ios_Openmode __a, _Ios_Openmode __b) _GLIBCXX_NOTHROW
{ return _Ios_Openmode(static_cast<int>(__a) & static_cast<int>(__b)); }
_GLIBCXX_NODISCARD _GLIBCXX_CONSTEXPR
inline _Ios_Openmode
operator|(_Ios_Openmode __a, _Ios_Openmode __b) _GLIBCXX_NOTHROW
{ return _Ios_Openmode(static_cast<int>(__a) | static_cast<int>(__b)); }
_GLIBCXX_NODISCARD _GLIBCXX_CONSTEXPR
inline _Ios_Openmode
operator^(_Ios_Openmode __a, _Ios_Openmode __b) _GLIBCXX_NOTHROW
{ return _Ios_Openmode(static_cast<int>(__a) ^ static_cast<int>(__b)); }
_GLIBCXX_NODISCARD _GLIBCXX_CONSTEXPR
inline _Ios_Openmode
operator~(_Ios_Openmode __a) _GLIBCXX_NOTHROW
{ return _Ios_Openmode(~static_cast<int>(__a)); }
_GLIBCXX14_CONSTEXPR
inline const _Ios_Openmode&
operator|=(_Ios_Openmode& __a, _Ios_Openmode __b) _GLIBCXX_NOTHROW
{ return __a = __a | __b; }
_GLIBCXX14_CONSTEXPR
inline const _Ios_Openmode&
operator&=(_Ios_Openmode& __a, _Ios_Openmode __b) _GLIBCXX_NOTHROW
{ return __a = __a & __b; }
_GLIBCXX14_CONSTEXPR
inline const _Ios_Openmode&
operator^=(_Ios_Openmode& __a, _Ios_Openmode __b) _GLIBCXX_NOTHROW
{ return __a = __a ^ __b; }
enum _Ios_Iostate
{
_S_goodbit = 0,
_S_badbit = 1L << 0,
_S_eofbit = 1L << 1,
_S_failbit = 1L << 2,
_S_ios_iostate_end = 1L << 16,
_S_ios_iostate_max = __INT_MAX__,
_S_ios_iostate_min = ~__INT_MAX__
};
_GLIBCXX_NODISCARD _GLIBCXX_CONSTEXPR
inline _Ios_Iostate
operator&(_Ios_Iostate __a, _Ios_Iostate __b) _GLIBCXX_NOTHROW
{ return _Ios_Iostate(static_cast<int>(__a) & static_cast<int>(__b)); }
_GLIBCXX_NODISCARD _GLIBCXX_CONSTEXPR
inline _Ios_Iostate
operator|(_Ios_Iostate __a, _Ios_Iostate __b) _GLIBCXX_NOTHROW
{ return _Ios_Iostate(static_cast<int>(__a) | static_cast<int>(__b)); }
_GLIBCXX_NODISCARD _GLIBCXX_CONSTEXPR
inline _Ios_Iostate
operator^(_Ios_Iostate __a, _Ios_Iostate __b) _GLIBCXX_NOTHROW
{ return _Ios_Iostate(static_cast<int>(__a) ^ static_cast<int>(__b)); }
_GLIBCXX_NODISCARD _GLIBCXX_CONSTEXPR
inline _Ios_Iostate
operator~(_Ios_Iostate __a) _GLIBCXX_NOTHROW
{ return _Ios_Iostate(~static_cast<int>(__a)); }
_GLIBCXX14_CONSTEXPR
inline const _Ios_Iostate&
operator|=(_Ios_Iostate& __a, _Ios_Iostate __b) _GLIBCXX_NOTHROW
{ return __a = __a | __b; }
_GLIBCXX14_CONSTEXPR
inline const _Ios_Iostate&
operator&=(_Ios_Iostate& __a, _Ios_Iostate __b) _GLIBCXX_NOTHROW
{ return __a = __a & __b; }
_GLIBCXX14_CONSTEXPR
inline const _Ios_Iostate&
operator^=(_Ios_Iostate& __a, _Ios_Iostate __b) _GLIBCXX_NOTHROW
{ return __a = __a ^ __b; }
enum _Ios_Seekdir
{
_S_beg = 0,
_S_cur = _GLIBCXX_STDIO_SEEK_CUR,
_S_end = _GLIBCXX_STDIO_SEEK_END,
_S_ios_seekdir_end = 1L << 16
};
#if __cplusplus >= 201103L
/// I/O error code
enum class io_errc { stream = 1 };
template <> struct is_error_code_enum<io_errc> : public true_type { };
[[__nodiscard__, __gnu__::__const__]]
const error_category&
iostream_category() noexcept;
[[__nodiscard__]]
inline error_code
make_error_code(io_errc __e) noexcept
{ return error_code(static_cast<int>(__e), iostream_category()); }
[[__nodiscard__]]
inline error_condition
make_error_condition(io_errc __e) noexcept
{ return error_condition(static_cast<int>(__e), iostream_category()); }
#endif
// 27.4.2 Class ios_base
/**
* @brief The base of the I/O class hierarchy.
* @ingroup io
*
* 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 @c ios_base when they need to specify the full
* name of the various I/O flags (e.g., the openmodes).
*/
class ios_base
{
#if _GLIBCXX_USE_CXX11_ABI
#if __cplusplus < 201103L
// Type that is layout-compatible with std::system_error
struct system_error : std::runtime_error
{
// Type that is layout-compatible with std::error_code
struct error_code
{
error_code() { }
private:
int _M_value;
const void* _M_cat;
} _M_code;
};
#endif
#endif
public:
/**
* @brief These are thrown to indicate problems with io.
* @ingroup exceptions
*
* 27.4.2.1.1 Class ios_base::failure
*/
#if _GLIBCXX_USE_CXX11_ABI
class _GLIBCXX_ABI_TAG_CXX11 failure : public system_error
{
public:
explicit
failure(const string& __str);
#if __cplusplus >= 201103L
explicit
failure(const string&, const error_code&);
explicit
failure(const char*, const error_code& = io_errc::stream);
#endif
virtual
~failure() throw();
virtual const char*
what() const throw();
};
#else
class failure : public exception
{
public:
// _GLIBCXX_RESOLVE_LIB_DEFECTS
// 48. Use of non-existent exception constructor
explicit
failure(const string& __str) throw();
// This declaration is not useless:
// http://gcc.gnu.org/onlinedocs/gcc-4.3.2/gcc/Vague-Linkage.html
virtual
~failure() throw();
virtual const char*
what() const throw();
#if __cplusplus >= 201103L
// Define the new members required by C++11,
// even though the error_code cannot be stored.
explicit
failure(const string& __s, const error_code&) noexcept
: failure(__s)
{ }
explicit
failure(const char* __s, const error_code& = error_code{})
: failure(string(__s))
{ }
// Stand-in for system_error::code() but returning by value.
error_code code() const noexcept { return error_code{}; }
#endif
private:
string _M_msg;
};
#endif
// 27.4.2.1.2 Type ios_base::fmtflags
/**
* @brief This is a bitmask type.
*
* @c @a _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
*/
typedef _Ios_Fmtflags fmtflags;
/// Insert/extract @c bool in alphabetic rather than numeric format.
static const fmtflags boolalpha = _S_boolalpha;
/// Converts integer input or generates integer output in decimal base.
static const fmtflags dec = _S_dec;
/// Generate floating-point output in fixed-point notation.
static const fmtflags fixed = _S_fixed;
/// Converts integer input or generates integer output in hexadecimal base.
static const fmtflags hex = _S_hex;
/// Adds fill characters at a designated internal point in certain
/// generated output, or identical to @c right if no such point is
/// designated.
static const fmtflags internal = _S_internal;
/// Adds fill characters on the right (final positions) of certain
/// generated output. (I.e., the thing you print is flush left.)
static const fmtflags left = _S_left;
/// Converts integer input or generates integer output in octal base.
static const fmtflags oct = _S_oct;
/// Adds fill characters on the left (initial positions) of certain
/// generated output. (I.e., the thing you print is flush right.)
static const fmtflags right = _S_right;
/// Generates floating-point output in scientific notation.
static const fmtflags scientific = _S_scientific;
/// Generates a prefix indicating the numeric base of generated integer
/// output.
static const fmtflags showbase = _S_showbase;
/// Generates a decimal-point character unconditionally in generated
/// floating-point output.
static const fmtflags showpoint = _S_showpoint;
/// Generates a + sign in non-negative generated numeric output.
static const fmtflags showpos = _S_showpos;
/// Skips leading white space before certain input operations.
static const fmtflags skipws = _S_skipws;
/// Flushes output after each output operation.
static const fmtflags unitbuf = _S_unitbuf;
/// Replaces certain lowercase letters with their uppercase equivalents
/// in generated output.
static const fmtflags uppercase = _S_uppercase;
/// A mask of left|right|internal. Useful for the 2-arg form of @c setf.
static const fmtflags adjustfield = _S_adjustfield;
/// A mask of dec|oct|hex. Useful for the 2-arg form of @c setf.
static const fmtflags basefield = _S_basefield;
/// A mask of scientific|fixed. Useful for the 2-arg form of @c setf.
static const fmtflags floatfield = _S_floatfield;
// 27.4.2.1.3 Type ios_base::iostate
/**
* @brief This is a bitmask type.
*
* @c @a _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
*/
typedef _Ios_Iostate iostate;
/// Indicates a loss of integrity in an input or output sequence (such
/// as an irrecoverable read error from a file).
static const iostate badbit = _S_badbit;
/// Indicates that an input operation reached the end of an input sequence.
static const iostate eofbit = _S_eofbit;
/// Indicates that an input operation failed to read the expected
/// characters, or that an output operation failed to generate the
/// desired characters.
static const iostate failbit = _S_failbit;
/// Indicates all is well.
static const iostate goodbit = _S_goodbit;
// 27.4.2.1.4 Type ios_base::openmode
/**
* @brief This is a bitmask type.
*
* @c @a _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
*/
typedef _Ios_Openmode openmode;
/// Seek to end before each write.
static const openmode app = _S_app;
/// Open and seek to end immediately after opening.
static const openmode ate = _S_ate;
/// 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 openmode binary = _S_bin;
/// Open for input. Default for @c ifstream and fstream.
static const openmode in = _S_in;
/// Open for output. Default for @c ofstream and fstream.
static const openmode out = _S_out;
/// Truncate an existing stream when opening. Default for @c ofstream.
static const openmode trunc = _S_trunc;
static const openmode __noreplace = _S_noreplace;
#ifdef __glibcxx_ios_noreplace // C++ >= 23 && HOSTED
/// Open a file in exclusive mode.
static const openmode noreplace = _S_noreplace;
#endif
// 27.4.2.1.5 Type ios_base::seekdir
/**
* @brief This is an enumerated type.
*
* @c @a _Ios_Seekdir is implementation-defined. Defined values
* of type seekdir are:
* - beg
* - cur, equivalent to @c SEEK_CUR in the C standard library.
* - end, equivalent to @c SEEK_END in the C standard library.
*/
typedef _Ios_Seekdir seekdir;
/// Request a seek relative to the beginning of the stream.
static const seekdir beg = _S_beg;
/// Request a seek relative to the current position within the sequence.
static const seekdir cur = _S_cur;
/// Request a seek relative to the current end of the sequence.
static const seekdir end = _S_end;
#if __cplusplus <= 201402L
// Annex D.6 (removed in C++17)
typedef int io_state
_GLIBCXX_DEPRECATED_SUGGEST("std::iostate");
typedef int open_mode
_GLIBCXX_DEPRECATED_SUGGEST("std::openmode");
typedef int seek_dir
_GLIBCXX_DEPRECATED_SUGGEST("std::seekdir");
typedef std::streampos streampos
_GLIBCXX_DEPRECATED_SUGGEST("std::streampos");
typedef std::streamoff streamoff
_GLIBCXX_DEPRECATED_SUGGEST("std::streamoff");
#endif
// Callbacks;
/**
* @brief 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().
*/
enum event
{
erase_event,
imbue_event,
copyfmt_event
};
/**
* @brief The type of an event callback function.
* @param __e One of the members of the event enum.
* @param __b Reference to the ios_base object.
* @param __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().
*/
typedef void (*event_callback) (event __e, ios_base& __b, int __i);
/**
* @brief Add the callback __fn with parameter __index.
* @param __fn The function to add.
* @param __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.
*/
void
register_callback(event_callback __fn, int __index);
protected:
streamsize _M_precision;
streamsize _M_width;
fmtflags _M_flags;
iostate _M_exception;
iostate _M_streambuf_state;
// 27.4.2.6 Members for callbacks
// 27.4.2.6 ios_base callbacks
struct _Callback_list
{
// Data Members
_Callback_list* _M_next;
ios_base::event_callback _M_fn;
int _M_index;
_Atomic_word _M_refcount; // 0 means one reference.
_Callback_list(ios_base::event_callback __fn, int __index,
_Callback_list* __cb)
: _M_next(__cb), _M_fn(__fn), _M_index(__index), _M_refcount(0) { }
void
_M_add_reference() { __gnu_cxx::__atomic_add_dispatch(&_M_refcount, 1); }
// 0 => OK to delete.
int
_M_remove_reference()
{
// Be race-detector-friendly. For more info see bits/c++config.
_GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&_M_refcount);
int __res = __gnu_cxx::__exchange_and_add_dispatch(&_M_refcount, -1);
if (__res == 0)
{
_GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&_M_refcount);
}
return __res;
}
};
_Callback_list* _M_callbacks;
void
_M_call_callbacks(event __ev) throw();
void
_M_dispose_callbacks(void) throw();
// 27.4.2.5 Members for iword/pword storage
struct _Words
{
void* _M_pword;
long _M_iword;
_Words() : _M_pword(0), _M_iword(0) { }
};
// Only for failed iword/pword calls.
_Words _M_word_zero;
// Guaranteed storage.
// The first 5 iword and pword slots are reserved for internal use.
enum { _S_local_word_size = 8 };
_Words _M_local_word[_S_local_word_size];
// Allocated storage.
int _M_word_size;
_Words* _M_word;
_Words&
_M_grow_words(int __index, bool __iword);
// Members for locale and locale caching.
locale _M_ios_locale;
void
_M_init() throw();
public:
// 27.4.2.1.6 Class ios_base::Init
// Used to initialize standard streams. In theory, g++ could use
// -finit-priority to order this stuff correctly without going
// through these machinations.
class Init
{
friend class ios_base;
public:
Init();
~Init();
#if __cplusplus >= 201103L
Init(const Init&) = default;
Init& operator=(const Init&) = default;
#endif
private:
static _Atomic_word _S_refcount;
static bool _S_synced_with_stdio;
};
// [27.4.2.2] fmtflags state functions
/**
* @brief Access to format flags.
* @return The format control flags for both input and output.
*/
_GLIBCXX_NODISCARD
fmtflags
flags() const
{ return _M_flags; }
/**
* @brief Setting new format flags all at once.
* @param __fmtfl The new flags to set.
* @return The previous format control flags.
*
* This function overwrites all the format flags with @a __fmtfl.
*/
fmtflags
flags(fmtflags __fmtfl)
{
fmtflags __old = _M_flags;
_M_flags = __fmtfl;
return __old;
}
/**
* @brief Setting new format flags.
* @param __fmtfl Additional flags to set.
* @return The previous format control flags.
*
* This function sets additional flags in format control. Flags that
* were previously set remain set.
*/
fmtflags
setf(fmtflags __fmtfl)
{
fmtflags __old = _M_flags;
_M_flags |= __fmtfl;
return __old;
}
/**
* @brief Setting new format flags.
* @param __fmtfl Additional flags to set.
* @param __mask The flags mask for @a fmtfl.
* @return The previous format control flags.
*
* This function clears @a mask in the format flags, then sets
* @a fmtfl @c & @a mask. An example mask is @c ios_base::adjustfield.
*/
fmtflags
setf(fmtflags __fmtfl, fmtflags __mask)
{
fmtflags __old = _M_flags;
_M_flags &= ~__mask;
_M_flags |= (__fmtfl & __mask);
return __old;
}
/**
* @brief Clearing format flags.
* @param __mask The flags to unset.
*
* This function clears @a __mask in the format flags.
*/
void
unsetf(fmtflags __mask)
{ _M_flags &= ~__mask; }
/**
* @brief Flags access.
* @return The precision to generate on certain output operations.
*
* Be careful if you try to give a definition of @a precision here; see
* DR 189.
*/
_GLIBCXX_NODISCARD
streamsize
precision() const
{ return _M_precision; }
/**
* @brief Changing flags.
* @param __prec The new precision value.
* @return The previous value of precision().
*/
streamsize
precision(streamsize __prec)
{
streamsize __old = _M_precision;
_M_precision = __prec;
return __old;
}
/**
* @brief Flags access.
* @return The minimum field width to generate on output operations.
*
* <em>Minimum field width</em> refers to the number of characters.
*/
_GLIBCXX_NODISCARD
streamsize
width() const
{ return _M_width; }
/**
* @brief Changing flags.
* @param __wide The new width value.
* @return The previous value of width().
*/
streamsize
width(streamsize __wide)
{
streamsize __old = _M_width;
_M_width = __wide;
return __old;
}
// [27.4.2.4] ios_base static members
/**
* @brief Interaction with the standard C I/O objects.
* @param __sync Whether to synchronize or not.
* @return True if the standard streams were previously synchronized.
*
* The synchronization referred to is @e 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
*/
static bool
sync_with_stdio(bool __sync = true);
// [27.4.2.3] ios_base locale functions
/**
* @brief Setting a new locale.
* @param __loc The new locale.
* @return The previous locale.
*
* Sets the new locale for this stream, and then invokes each callback
* with imbue_event.
*/
locale
imbue(const locale& __loc) throw();
/**
* @brief Locale access
* @return A copy of the current locale.
*
* If @c imbue(loc) has previously been called, then this function
* returns @c loc. Otherwise, it returns a copy of @c std::locale(),
* the global C++ locale.
*/
_GLIBCXX_NODISCARD
locale
getloc() const
{ return _M_ios_locale; }
/**
* @brief Locale access
* @return A reference to the current locale.
*
* Like getloc above, but returns a reference instead of
* generating a copy.
*/
const locale&
_M_getloc() const
{ return _M_ios_locale; }
// [27.4.2.5] ios_base storage functions
/**
* @brief Access to unique indices.
* @return An integer different from all previous calls.
*
* This function returns a unique integer every time it is called. It
* can be used for any purpose, but is primarily intended to be a unique
* index for the iword and pword functions. The expectation is that an
* application calls xalloc in order to obtain an index in the iword and
* pword arrays that can be used without fear of conflict.
*
* The implementation maintains a static variable that is incremented and
* returned on each invocation. xalloc is guaranteed to return an index
* that is safe to use in the iword and pword arrays.
*/
static int
xalloc() throw();
/**
* @brief Access to integer array.
* @param __ix Index into the array.
* @return A reference to an integer associated with the index.
*
* The iword function provides access to an array of integers that can be
* used for any purpose. The array grows as required to hold the
* supplied index. All integers in the array are initialized to 0.
*
* The implementation reserves several indices. You should use xalloc to
* obtain an index that is safe to use. Also note that since the array
* can grow dynamically, it is not safe to hold onto the reference.
*/
long&
iword(int __ix)
{
_Words& __word = ((unsigned)__ix < (unsigned)_M_word_size)
? _M_word[__ix] : _M_grow_words(__ix, true);
return __word._M_iword;
}
/**
* @brief Access to void pointer array.
* @param __ix Index into the array.
* @return A reference to a void* associated with the index.
*
* The pword function provides access to an array of pointers that can be
* used for any purpose. The array grows as required to hold the
* supplied index. All pointers in the array are initialized to 0.
*
* The implementation reserves several indices. You should use xalloc to
* obtain an index that is safe to use. Also note that since the array
* can grow dynamically, it is not safe to hold onto the reference.
*/
void*&
pword(int __ix)
{
_Words& __word = ((unsigned)__ix < (unsigned)_M_word_size)
? _M_word[__ix] : _M_grow_words(__ix, false);
return __word._M_pword;
}
// Destructor
/**
* 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).
*/
virtual ~ios_base();
protected:
ios_base() throw ();
#if __cplusplus < 201103L
// _GLIBCXX_RESOLVE_LIB_DEFECTS
// 50. Copy constructor and assignment operator of ios_base
private:
ios_base(const ios_base&);
ios_base&
operator=(const ios_base&);
#else
public:
ios_base(const ios_base&) = delete;
ios_base&
operator=(const ios_base&) = delete;
protected:
void
_M_move(ios_base&) noexcept;
void
_M_swap(ios_base& __rhs) noexcept;
#endif
};
// [27.4.5.1] fmtflags manipulators
/// Calls base.setf(ios_base::boolalpha).
inline ios_base&
boolalpha(ios_base& __base)
{
__base.setf(ios_base::boolalpha);
return __base;
}
/// Calls base.unsetf(ios_base::boolalpha).
inline ios_base&
noboolalpha(ios_base& __base)
{
__base.unsetf(ios_base::boolalpha);
return __base;
}
/// Calls base.setf(ios_base::showbase).
inline ios_base&
showbase(ios_base& __base)
{
__base.setf(ios_base::showbase);
return __base;
}
/// Calls base.unsetf(ios_base::showbase).
inline ios_base&
noshowbase(ios_base& __base)
{
__base.unsetf(ios_base::showbase);
return __base;
}
/// Calls base.setf(ios_base::showpoint).
inline ios_base&
showpoint(ios_base& __base)
{
__base.setf(ios_base::showpoint);
return __base;
}
/// Calls base.unsetf(ios_base::showpoint).
inline ios_base&
noshowpoint(ios_base& __base)
{
__base.unsetf(ios_base::showpoint);
return __base;
}
/// Calls base.setf(ios_base::showpos).
inline ios_base&
showpos(ios_base& __base)
{
__base.setf(ios_base::showpos);
return __base;
}
/// Calls base.unsetf(ios_base::showpos).
inline ios_base&
noshowpos(ios_base& __base)
{
__base.unsetf(ios_base::showpos);
return __base;
}
/// Calls base.setf(ios_base::skipws).
inline ios_base&
skipws(ios_base& __base)
{
__base.setf(ios_base::skipws);
return __base;
}
/// Calls base.unsetf(ios_base::skipws).
inline ios_base&
noskipws(ios_base& __base)
{
__base.unsetf(ios_base::skipws);
return __base;
}
/// Calls base.setf(ios_base::uppercase).
inline ios_base&
uppercase(ios_base& __base)
{
__base.setf(ios_base::uppercase);
return __base;
}
/// Calls base.unsetf(ios_base::uppercase).
inline ios_base&
nouppercase(ios_base& __base)
{
__base.unsetf(ios_base::uppercase);
return __base;
}
/// Calls base.setf(ios_base::unitbuf).
inline ios_base&
unitbuf(ios_base& __base)
{
__base.setf(ios_base::unitbuf);
return __base;
}
/// Calls base.unsetf(ios_base::unitbuf).
inline ios_base&
nounitbuf(ios_base& __base)
{
__base.unsetf(ios_base::unitbuf);
return __base;
}
// [27.4.5.2] adjustfield manipulators
/// Calls base.setf(ios_base::internal, ios_base::adjustfield).
inline ios_base&
internal(ios_base& __base)
{
__base.setf(ios_base::internal, ios_base::adjustfield);
return __base;
}
/// Calls base.setf(ios_base::left, ios_base::adjustfield).
inline ios_base&
left(ios_base& __base)
{
__base.setf(ios_base::left, ios_base::adjustfield);
return __base;
}
/// Calls base.setf(ios_base::right, ios_base::adjustfield).
inline ios_base&
right(ios_base& __base)
{
__base.setf(ios_base::right, ios_base::adjustfield);
return __base;
}
// [27.4.5.3] basefield manipulators
/// Calls base.setf(ios_base::dec, ios_base::basefield).
inline ios_base&
dec(ios_base& __base)
{
__base.setf(ios_base::dec, ios_base::basefield);
return __base;
}
/// Calls base.setf(ios_base::hex, ios_base::basefield).
inline ios_base&
hex(ios_base& __base)
{
__base.setf(ios_base::hex, ios_base::basefield);
return __base;
}
/// Calls base.setf(ios_base::oct, ios_base::basefield).
inline ios_base&
oct(ios_base& __base)
{
__base.setf(ios_base::oct, ios_base::basefield);
return __base;
}
// [27.4.5.4] floatfield manipulators
/// Calls base.setf(ios_base::fixed, ios_base::floatfield).
inline ios_base&
fixed(ios_base& __base)
{
__base.setf(ios_base::fixed, ios_base::floatfield);
return __base;
}
/// Calls base.setf(ios_base::scientific, ios_base::floatfield).
inline ios_base&
scientific(ios_base& __base)
{
__base.setf(ios_base::scientific, ios_base::floatfield);
return __base;
}
#if __cplusplus >= 201103L
// New C++11 floatfield manipulators
/// Calls
/// base.setf(ios_base::fixed|ios_base::scientific, ios_base::floatfield)
inline ios_base&
hexfloat(ios_base& __base)
{
__base.setf(ios_base::fixed | ios_base::scientific, ios_base::floatfield);
return __base;
}
/// Calls @c base.unsetf(ios_base::floatfield)
inline ios_base&
defaultfloat(ios_base& __base)
{
__base.unsetf(ios_base::floatfield);
return __base;
}
#endif
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace
#endif /* _IOS_BASE_H */
stdexcept
system_error
locale_classes.h
localefwd.h
atomicity.h
std::make_error_condition
error_condition make_error_condition(future_errc __errc) noexcept
Overload of make_error_condition for future_errc.
Definition future:102
std::make_error_code
error_code make_error_code(future_errc __errc) noexcept
Overload of make_error_code for future_errc.
Definition future:96
std::ios_base::fmtflags
class __attribute((__abi_tag__("cxx11"))) failure typedef _Ios_Fmtflags fmtflags
These are thrown to indicate problems with io.
Definition ios_base.h:292
std
ISO C++ entities toplevel namespace is std.
std::scientific
ios_base & scientific(ios_base &__base)
Calls base.setf(ios_base::scientific, ios_base::floatfield).
Definition ios_base.h:1127
std::internal
ios_base & internal(ios_base &__base)
Calls base.setf(ios_base::internal, ios_base::adjustfield).
Definition ios_base.h:1069
std::noskipws
ios_base & noskipws(ios_base &__base)
Calls base.unsetf(ios_base::skipws).
Definition ios_base.h:1028
std::streamsize
ptrdiff_t streamsize
Integral type for I/O operation counts and buffer sizes.
Definition postypes.h:73
std::hex
ios_base & hex(ios_base &__base)
Calls base.setf(ios_base::hex, ios_base::basefield).
Definition ios_base.h:1102
std::left
ios_base & left(ios_base &__base)
Calls base.setf(ios_base::left, ios_base::adjustfield).
Definition ios_base.h:1077
std::noshowpoint
ios_base & noshowpoint(ios_base &__base)
Calls base.unsetf(ios_base::showpoint).
Definition ios_base.h:996
std::unitbuf
ios_base & unitbuf(ios_base &__base)
Calls base.setf(ios_base::unitbuf).
Definition ios_base.h:1052
std::nounitbuf
ios_base & nounitbuf(ios_base &__base)
Calls base.unsetf(ios_base::unitbuf).
Definition ios_base.h:1060
std::showbase
ios_base & showbase(ios_base &__base)
Calls base.setf(ios_base::showbase).
Definition ios_base.h:972
std::streamoff
long long streamoff
Type used by fpos, char_traits<char>, and char_traits<wchar_t>.
Definition postypes.h:68
std::streampos
fpos< mbstate_t > streampos
File position for char streams.
Definition postypes.h:209
std::io_errc
io_errc
I/O error code.
Definition ios_base.h:236
std::noshowpos
ios_base & noshowpos(ios_base &__base)
Calls base.unsetf(ios_base::showpos).
Definition ios_base.h:1012
std::nouppercase
ios_base & nouppercase(ios_base &__base)
Calls base.unsetf(ios_base::uppercase).
Definition ios_base.h:1044
std::noshowbase
ios_base & noshowbase(ios_base &__base)
Calls base.unsetf(ios_base::showbase).
Definition ios_base.h:980
std::oct
ios_base & oct(ios_base &__base)
Calls base.setf(ios_base::oct, ios_base::basefield).
Definition ios_base.h:1110
std::dec
ios_base & dec(ios_base &__base)
Calls base.setf(ios_base::dec, ios_base::basefield).
Definition ios_base.h:1094
std::right
ios_base & right(ios_base &__base)
Calls base.setf(ios_base::right, ios_base::adjustfield).
Definition ios_base.h:1085
std::operator^
constexpr bitset< _Nb > operator^(const bitset< _Nb > &__x, const bitset< _Nb > &__y) noexcept
Global bitwise operations on bitsets.
Definition bitset:1582
std::showpoint
ios_base & showpoint(ios_base &__base)
Calls base.setf(ios_base::showpoint).
Definition ios_base.h:988
std::skipws
ios_base & skipws(ios_base &__base)
Calls base.setf(ios_base::skipws).
Definition ios_base.h:1020
std::fixed
ios_base & fixed(ios_base &__base)
Calls base.setf(ios_base::fixed, ios_base::floatfield).
Definition ios_base.h:1119
std::showpos
ios_base & showpos(ios_base &__base)
Calls base.setf(ios_base::showpos).
Definition ios_base.h:1004
std::hexfloat
ios_base & hexfloat(ios_base &__base)
Calls base.setf(ios_base::fixed|ios_basescientific, ios_base::floatfield).
Definition ios_base.h:1139
std::defaultfloat
ios_base & defaultfloat(ios_base &__base)
Calls base.unsetf(ios_base::floatfield).
Definition ios_base.h:1147
std::operator|
constexpr bitset< _Nb > operator|(const bitset< _Nb > &__x, const bitset< _Nb > &__y) noexcept
Global bitwise operations on bitsets.
Definition bitset:1572
std::uppercase
ios_base & uppercase(ios_base &__base)
Calls base.setf(ios_base::uppercase).
Definition ios_base.h:1036
std::boolalpha
ios_base & boolalpha(ios_base &__base)
Calls base.setf(ios_base::boolalpha).
Definition ios_base.h:956
std::noboolalpha
ios_base & noboolalpha(ios_base &__base)
Calls base.unsetf(ios_base::boolalpha).
Definition ios_base.h:964
std::operator&
constexpr bitset< _Nb > operator&(const bitset< _Nb > &__x, const bitset< _Nb > &__y) noexcept
Global bitwise operations on bitsets.
Definition bitset:1562
std::runtime_error
One of two subclasses of exception.
Definition stdexcept:222
std::error_category
Definition system_error:109
std::error_code
Definition system_error:226
std::error_condition
Definition system_error:357
std::system_error
An exception type that includes an error_code value.
Definition system_error:559
std::exception
Base class for all library exceptions.
Definition exception.h:62
std::ios_base
The base of the I/O class hierarchy.
Definition ios_base.h:266
std::ios_base::setf
fmtflags setf(fmtflags __fmtfl)
Setting new format flags.
Definition ios_base.h:721
std::ios_base::skipws
static const fmtflags skipws
Skips leading white space before certain input operations.
Definition ios_base.h:423
std::ios_base::iostate
_Ios_Iostate iostate
This is a bitmask type.
Definition ios_base.h:453
std::ios_base::hex
static const fmtflags hex
Converts integer input or generates integer output in hexadecimal base.
Definition ios_base.h:390
std::ios_base::right
static const fmtflags right
Adds fill characters on the left (initial positions) of certain generated output. (I....
Definition ios_base.h:406
std::ios_base::cur
static const seekdir cur
Request a seek relative to the current position within the sequence.
Definition ios_base.h:529
std::ios_base::uppercase
static const fmtflags uppercase
Replaces certain lowercase letters with their uppercase equivalents in generated output.
Definition ios_base.h:430
std::ios_base::basefield
static const fmtflags basefield
A mask of dec|oct|hex. Useful for the 2-arg form of setf.
Definition ios_base.h:436
std::ios_base::pword
void *& pword(int __ix)
Access to void pointer array.
Definition ios_base.h:908
std::ios_base::beg
static const seekdir beg
Request a seek relative to the beginning of the stream.
Definition ios_base.h:526
std::ios_base::precision
streamsize precision() const
Flags access.
Definition ios_base.h:765
std::ios_base::imbue
locale imbue(const locale &__loc)
Setting a new locale.
std::ios_base::dec
static const fmtflags dec
Converts integer input or generates integer output in decimal base.
Definition ios_base.h:384
std::ios_base::xalloc
static int xalloc()
Access to unique indices.
std::ios_base::event
event
The set of events that may be passed to an event callback.
Definition ios_base.h:557
std::ios_base::flags
fmtflags flags(fmtflags __fmtfl)
Setting new format flags all at once.
Definition ios_base.h:705
std::ios_base::unsetf
void unsetf(fmtflags __mask)
Clearing format flags.
Definition ios_base.h:753
std::ios_base::showpoint
static const fmtflags showpoint
Generates a decimal-point character unconditionally in generated floating-point output.
Definition ios_base.h:417
std::ios_base::end
static const seekdir end
Request a seek relative to the current end of the sequence.
Definition ios_base.h:532
std::ios_base::register_callback
void register_callback(event_callback __fn, int __index)
Add the callback __fn with parameter __index.
std::ios_base::in
static const openmode in
Open for input. Default for ifstream and fstream.
Definition ios_base.h:498
std::ios_base::showbase
static const fmtflags showbase
Generates a prefix indicating the numeric base of generated integer output.
Definition ios_base.h:413
std::ios_base::event_callback
void(* event_callback)(event __e, ios_base &__b, int __i)
The type of an event callback function.
Definition ios_base.h:573
std::ios_base::internal
static const fmtflags internal
Adds fill characters at a designated internal point in certain generated output, or identical to righ...
Definition ios_base.h:395
std::ios_base::iword
long & iword(int __ix)
Access to integer array.
Definition ios_base.h:887
std::ios_base::out
static const openmode out
Open for output. Default for ofstream and fstream.
Definition ios_base.h:501
std::ios_base::boolalpha
static const fmtflags boolalpha
Insert/extract bool in alphabetic rather than numeric format.
Definition ios_base.h:381
std::ios_base::~ios_base
virtual ~ios_base()
std::ios_base::flags
fmtflags flags() const
Access to format flags.
Definition ios_base.h:694
std::ios_base::eofbit
static const iostate eofbit
Indicates that an input operation reached the end of an input sequence.
Definition ios_base.h:460
std::ios_base::floatfield
static const fmtflags floatfield
A mask of scientific|fixed. Useful for the 2-arg form of setf.
Definition ios_base.h:439
std::ios_base::setf
fmtflags setf(fmtflags __fmtfl, fmtflags __mask)
Setting new format flags.
Definition ios_base.h:738
std::ios_base::binary
static const openmode binary
Perform input and output in binary mode (as opposed to text mode). This is probably not what you thin...
Definition ios_base.h:495
std::ios_base::goodbit
static const iostate goodbit
Indicates all is well.
Definition ios_base.h:468
std::ios_base::_M_getloc
const locale & _M_getloc() const
Locale access.
Definition ios_base.h:852
std::ios_base::unitbuf
static const fmtflags unitbuf
Flushes output after each output operation.
Definition ios_base.h:426
std::ios_base::badbit
static const iostate badbit
Indicates a loss of integrity in an input or output sequence (such as an irrecoverable read error fro...
Definition ios_base.h:457
std::ios_base::openmode
_Ios_Openmode openmode
This is a bitmask type.
Definition ios_base.h:484
std::ios_base::width
streamsize width() const
Flags access.
Definition ios_base.h:789
std::ios_base::sync_with_stdio
static bool sync_with_stdio(bool __sync=true)
Interaction with the standard C I/O objects.
std::ios_base::fixed
static const fmtflags fixed
Generate floating-point output in fixed-point notation.
Definition ios_base.h:387
std::ios_base::oct
static const fmtflags oct
Converts integer input or generates integer output in octal base.
Definition ios_base.h:402
std::ios_base::app
static const openmode app
Seek to end before each write.
Definition ios_base.h:487
std::ios_base::seekdir
_Ios_Seekdir seekdir
This is an enumerated type.
Definition ios_base.h:523
std::ios_base::width
streamsize width(streamsize __wide)
Changing flags.
Definition ios_base.h:798
std::ios_base::left
static const fmtflags left
Adds fill characters on the right (final positions) of certain generated output. (I....
Definition ios_base.h:399
std::ios_base::showpos
static const fmtflags showpos
Generates a + sign in non-negative generated numeric output.
Definition ios_base.h:420
std::ios_base::ate
static const openmode ate
Open and seek to end immediately after opening.
Definition ios_base.h:490
std::ios_base::getloc
locale getloc() const
Locale access.
Definition ios_base.h:841
std::ios_base::trunc
static const openmode trunc
Truncate an existing stream when opening. Default for ofstream.
Definition ios_base.h:504
std::ios_base::precision
streamsize precision(streamsize __prec)
Changing flags.
Definition ios_base.h:774
std::ios_base::failbit
static const iostate failbit
Indicates that an input operation failed to read the expected characters, or that an output operation...
Definition ios_base.h:465
std::ios_base::scientific
static const fmtflags scientific
Generates floating-point output in scientific notation.
Definition ios_base.h:409
std::ios_base::adjustfield
static const fmtflags adjustfield
A mask of left|right|internal. Useful for the 2-arg form of setf.
Definition ios_base.h:433
std::locale
Container class for localization functionality.
Definition locale_classes.h:69