STD::BASIC_STRINGSTREAM(3cxx)

📦

version 14-20240412 · 26 versions

okay bestie, welcome to the std::basic_stri...raits, _Alloc >(3cxx) page — part 1 of 10, and we are not skipping a single crumb. The manual name is folded in right here so you can find it without the wonky header line. 💅

💖 NAME 💖

std::basic_stringstream< _CharT, _Traits, _Alloc > — controlling input and output for std::string. That's the whole vibe: it's the string-stream bestie.

✨ SYNOPSIS ✨

#include <sstream>

Inherits std::basic_iostream< _CharT, _Traits >.

🎀 Public Types 🎀

typedef ctype< _CharT > __ctype_type
typedef ctype< _CharT > __ctype_type — yes, it's listed twice in the original, don't come for me 💀
typedef basic_ios< _CharT, _Traits > __ios_type
typedef basic_ios< _CharT, _Traits > __ios_type — also twice, and we're keeping it
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 — another twin, iconic
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 _Ios_Iostate iostate — this is a bitmask type.
typedef traits_type::off_type off_type
typedef _Ios_Openmode openmode — this is a bitmask type.
typedef traits_type::pos_type pos_type
typedef _Ios_Seekdir seekdir — this is an enumerated type.
typedef _Traits traits_type
typedef num_put< _CharT, ostreambuf_iterator< _CharT, _Traits > > __num_put_type — yep, it shows up again at the end, that's the original's whole thing 🫶

🌸 Public Member Functions 🌸

okay, deep breath, bestie — this is the big list. Every signature stays exactly as written; only the commentary is getting the group-chat treatment. 💖

basic_stringstream () — default constructor, starts with an empty string buffer.
basic_stringstream (basic_stringstream &&__rhs)
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 (ios_base::openmode __m) — starts with an empty string buffer.
~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.
basic_istream< char > & getline (char_type *__s, streamsize __n, char_type __delim) — explicit specialization declarations, defined in src/istream.cc.
basic_istream< wchar_t > & getline (char_type *__s, streamsize __n, char_type __delim)
locale getloc () const — locale access.
bool good () const — fast error checking.
basic_istream< char > & ignore (streamsize __n)
basic_istream< wchar_t > & ignore (streamsize __n)
basic_istream< char > & ignore (streamsize __n, int_type __delim)
basic_istream< wchar_t > & ignore (streamsize __n, int_type __delim)
locale imbue (const locale &__loc) — moves to a new locale.
long & iword (int __ix) — access to integer array.
char narrow (char_type __c, char __dfault) const — squeezes characters.
__ostream_type & operator<< (__streambuf_type *__sb) — extracting from another streambuf.
__ostream_type & operator<< (const void *__p) — pointer arithmetic inserters.
__ostream_type & operator<< (nullptr_t)
basic_stringstream & operator= (basic_stringstream &&__rhs)
basic_stringstream & operator= (const basic_stringstream &)=delete
__istream_type & operator>> (__streambuf_type *__sb) — extracting into another streambuf.
__istream_type & operator>> (void *&__p) — basic arithmetic extractors.
streamsize precision () const — flags access.
streamsize precision (streamsize __prec) — changing flags.
void *& pword (int __ix) — access to void pointer array.
__stringbuf_type * rdbuf () const — accessing the underlying buffer.
basic_streambuf< _CharT, _Traits > * rdbuf (basic_streambuf< _CharT, _Traits > *__sb) — changing the underlying buffer.
iostate rdstate () const — returns the error state of the stream buffer.
void register_callback (event_callback __fn, int __index) — add the callback __fn with parameter __index.
__ostream_type & seekp (off_type, ios_base::seekdir) — changing the current write position.
__ostream_type & seekp (pos_type) — 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.
basic_string_view< char_type, traits_type > view () const noexcept
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 🔥

okay so every single operator>> (a.k.a. the formatted input functions) shares some common behavior. Each one starts by constructing a temporary object of type std::basic_istream::sentry with the second argument (noskipws) set to false. That does several things, and it ends with setting a status flag; peek the sentry documentation for the full lore.

If the sentry status is good, the function tries to extract whatever data is appropriate for the type of the argument.

If an exception is thrown during extraction, ios_base::badbit will be turned on in the stream's error state (without causing an ios_base::failure to be thrown) and the original exception will be rethrown if badbit is set in the exceptions mask.

__istream_type & operator>> (bool &__n) — integer arithmetic extractors.
__istream_type & operator>> (short &__n) — integer arithmetic extractors.
__istream_type & operator>> (unsigned short &__n) — integer arithmetic extractors.
__istream_type & operator>> (int &__n) — integer arithmetic extractors.
__istream_type & operator>> (unsigned int &__n) — integer arithmetic extractors.
__istream_type & operator>> (long &__n) — integer arithmetic extractors.
__istream_type & operator>> (unsigned long &__n) — integer arithmetic extractors.
__istream_type & operator>> (long long &__n) — integer arithmetic extractors.
__istream_type & operator>> (unsigned long long &__n) — integer arithmetic extractors.
__istream_type & operator>> (float &__f) — floating point arithmetic extractors.
__istream_type & operator>> (double &__f) — floating point arithmetic extractors.
__istream_type & operator>> (long double &__f) — floating point arithmetic extractors.

🫶 Unformatted Input Functions 🫶

All the unformatted input functions have some common behavior too. Each one starts by constructing a temporary object of type std::basic_istream::sentry with the second argument (noskipws) set to true. That 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().

int_type get () — the simplest lil extraction, literally just grab one character and go 🫶
__istream_type & get (char_type &__c) — same simple extraction, except the character lands in __c
__istream_type & get (char_type *__s, streamsize __n, char_type __delim) — simple multiple-character extraction, stopping at __delim 💅
__istream_type & get (char_type *__s, streamsize __n) — simple multiple-character extraction, no delimiter era
__istream_type & get (__streambuf_type &__sb, char_type __delim) — extraction straight into another streambuf, stopping at __delim
__istream_type & get (__streambuf_type &__sb) — extraction into another streambuf, periodt
__istream_type & getline (char_type *__s, streamsize __n, char_type __delim) — string extraction 🎀
__istream_type & getline (char_type *__s, streamsize __n) — string extraction, default vibes
__istream_type & ignore (streamsize __n, int_type __delim) — discarding characters, we simply do not perceive them ✨
__istream_type & ignore (streamsize __n) — simple extraction (yes bestie, the label really does say that)
__istream_type & ignore () — simple extraction again, no args no thoughts
int_type peek () — looking ahead in the stream 👀 you're nosy but make it legal
__istream_type & read (char_type *__s, streamsize __n) — extraction without delimiters, no manners at all
streamsize readsome (char_type *__s, streamsize __n) — extraction until the buffer is exhausted, but no more. Respects the limit fr fr
__istream_type & putback (char_type __c) — unextracting a single character, gaslighting the stream into thinking it never left
__istream_type & unget () — unextracting the previous character, the uno reverse card 🦋
int sync () — synchronizing the stream buffer
pos_type tellg () — getting the current read position, where are we even 📍
__istream_type & seekg (pos_type) — changing the current read position
__istream_type & seekg (off_type, ios_base::seekdir) — changing the current read position, but with extra instructions
operator bool () const — the quick-and-easy status check 👑
bool operator! () const — the quick-and-easy status check, but inverted bestie
__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 🌈

okay so listen, all the operator<< functions (aka the formatted output functions, fancy name i know) have some common behavior, and you will be tested on it 💀

Each one starts by constructing a temporary object of type std::basic_ostream::sentry. That lil guy can have several effects, and it concludes with the setting of a status flag — see the sentry documentation for more, i'm not doing its whole lore dump here.

If the sentry status is good, the function tries to generate whatever data is appropriate for the type of the argument. simple as that ✨

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. so like, chaos but contained 🙈

__ostream_type & operator<< (long __n) — integer arithmetic inserter
__ostream_type & operator<< (unsigned long __n) — integer arithmetic inserter
__ostream_type & operator<< (bool __n) — integer arithmetic inserter
__ostream_type & operator<< (short __n) — integer arithmetic inserter
__ostream_type & operator<< (unsigned short __n) — integer arithmetic inserter
__ostream_type & operator<< (int __n) — integer arithmetic inserter
__ostream_type & operator<< (unsigned int __n) — integer arithmetic inserter
__ostream_type & operator<< (long long __n) — integer arithmetic inserter
__ostream_type & operator<< (unsigned long long __n) — integer arithmetic inserter
__ostream_type & operator<< (double __f) — floating point arithmetic inserter 🌸
__ostream_type & operator<< (float __f) — floating point arithmetic inserter
__ostream_type & operator<< (long double __f) — floating point arithmetic inserter

🧚 Unformatted Output Functions 🧚

bestie, these ones have their own common behavior, don't mix them up 🎀

Each one 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, again.

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. that's the difference, ok, write it down 📝

__ostream_type & put (char_type __c) — simple insertion
__ostream_type & write (const char_type *__s, streamsize __n) — character string insertion, the whole squad goes in 💜

⭐ Static Public Member Functions ⭐

static bool sync_with_stdio (bool __sync=true) — interaction with the standard C I/O objects. note the default __sync=true, she's opt-out
static int xalloc () throw () — access to unique indices 🔥

💖 Static Public Attributes 💖

static const openmode __noreplace
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. no cap, go read it 🙈
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 🫶 the good ending
static const fmtflags hex — converts integer input or generates integer output in hexadecimal base
static const openmode in — open for input. default for ifstream and fstream
static const fmtflags internal — adds fill characters at a designated internal point in certain generated output, or identical to right if no such point is designated
static const fmtflags left — adds fill characters on the right (final positions) of certain generated output. (I.e., the thing you print is flush left.)
static const fmtflags oct — converts integer input or generates integer output in octal base
static const openmode out — open for output. default for ofstream and fstream
static const fmtflags right — adds fill characters on the left (initial positions) of certain generated output. (I.e., the thing you print is flush right.)
static const fmtflags scientific — generates floating-point output in scientific notation
static const fmtflags showbase — generates a prefix indicating the numeric base of generated integer output
static const fmtflags showpoint — generates a decimal-point character unconditionally in generated floating-point output
static const fmtflags showpos — generates a + sign in non-negative generated numeric output
static const fmtflags skipws — skips leading white space before certain input operations
static const openmode trunc — truncate an existing stream when opening. default for ofstream
static const fmtflags unitbuf — flushes output after each output operation
static const fmtflags uppercase — replaces certain lowercase letters with their uppercase equivalents in generated output

🦋 Protected Types 🦋

enum { _S_local_word_size }

🌸 Protected Member Functions 🌸

void _M_cache_locale (const locale &__loc)
void _M_call_callbacks (event __ev) throw ()
void _M_dispose_callbacks (void) throw ()
template<typename _ValueT > __istream_type & _M_extract (_ValueT &__v)
_Words & _M_grow_words (int __index, bool __iword)
void _M_init () throw ()
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 ✨ one function to rule them all
void move (basic_ios &&__rhs)
void move (basic_ios &__rhs)
void set_rdbuf (basic_streambuf< _CharT, _Traits > *__sb)
void swap (basic_ios &__rhs) noexcept
void swap (basic_iostream &__rhs)
void swap (basic_istream &__rhs)
void swap (basic_ostream &__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. that's the whole assignment bestie, main character energy 💅

🎀 Template Parameters 🎀

_CharT — type of character stream
_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. and that's the tea ☕ iykyk

🌸 Member Typedef Documentation 🌸

💖 `std::basic_ios< _CharT, _Traits >::__num_put_type` (inherited)

template<typename _CharT , typename _Traits > typedef num_put<_CharT,
    ostreambuf_iterator<_CharT, _Traits> > std::basic_ios< _CharT, _Traits
    >::__num_put_type [inherited]

Heads up bestie: these are non-standard types. ✨

🎀 `std::ios_base::event_callback` (inherited)

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

The type of an event callback function. 💅

Parameters:

__e — one of the members of the event enum.
__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(). 🫶

🦋 `std::ios_base::fmtflags` (inherited)

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

🌈 `std::ios_base::iostate` (inherited)

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

🔥 `std::ios_base::openmode` (inherited)

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

👑 `std::ios_base::seekdir` (inherited)

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.

✨ Member Enumeration Documentation ✨

🧚 `enum std::ios_base::event` (inherited)

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(). 💖

🎀 Constructor & Destructor Documentation 🎀

💅 `basic_stringstream()` — default constructor

template<typename _CharT , typename _Traits , typename _Alloc >
    std::basic_stringstream< _CharT, _Traits, _Alloc >::basic_stringstream
    () [inline]

Default constructor starts with an empty string buffer. Initializes sb using the mode in|out, 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. 😭

References std::basic_ios< _CharT, _Traits >::init().

🫶 `basic_stringstream(ios_base::openmode __m)` — explicit

template<typename _CharT , typename _Traits , typename _Alloc >
    std::basic_stringstream< _CharT, _Traits, _Alloc >::basic_stringstream
    (ios_base::openmode __m) [inline],  [explicit]

Starts with an empty string buffer. 🌸

Parameters:

__m — whether the buffer can read, or write, or both.

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. 😭

References std::basic_ios< _CharT, _Traits >::init().

🦋 `basic_stringstream(const __string_type & __str, ios_base::openmode __m = ios_base::out | ios_base::in)` — explicit

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:

__str — a string to copy as a starting buffer.
__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. 😭

References std::basic_ios< _CharT, _Traits >::init().

🌈 `~basic_stringstream()` — destructor

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. 👑

💖 Member Function Documentation 💖

🌟 `std::ios_base::_M_getloc()` — inherited

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

Locale access. Returns a reference to the current locale. Like getloc above, but returns a reference instead of generating a copy. 🎀

Referenced by std::money_get< _CharT, _InIter >::do_get(), std::time_get< _CharT, _InIter >::do_get(), std::num_get< _CharT, _InIter >::do_get(), std::time_get< _CharT, _InIter >::do_get_date(), std::time_get< _CharT, _InIter >::do_get_monthname(), std::time_get< _CharT, _InIter >::do_get_time(), std::time_get< _CharT, _InIter >::do_get_weekday(), std::time_get< _CharT, _InIter >::do_get_year(), std::num_put< _CharT, _OutIter >::do_put(), std::time_put< _CharT, _OutIter >::do_put(), std::time_get< _CharT, _InIter >::get(), and std::time_put< _CharT, _OutIter >::put().

🦋 `std::basic_ios< _CharT, _Traits >::bad()` — inherited

template<typename _CharT , typename _Traits > bool std::basic_ios< _CharT,
    _Traits >::bad () const [inline],  [inherited]

Fast error checking. Returns true if the badbit is set. Note that other iostate flags may also be set. 💅

References std::ios_base::badbit, and std::basic_ios< _CharT, _Traits >::rdstate().

Referenced by std::basic_ostream< _CharT, _Traits >::sentry::sentry().

🔥 `std::basic_ios< _CharT, _Traits >::clear(iostate __state = goodbit)` — inherited

template<typename _CharT , typename _Traits > void std::basic_ios< _CharT,
    _Traits >::clear (iostate __state = goodbit) [inherited]

[Re]sets the error state. ✨

Parameters:

__state — the new state flag(s) to set.

See std::ios_base::iostate for the possible bit values. Most users will not need to pass an argument.

Referenced by std::basic_ios< _CharT, _Traits >::exceptions(), std::basic_ifstream< _CharT, _Traits >::open(), std::basic_fstream< _CharT, _Traits >::open(), std::basic_ofstream< _CharT, _Traits >::open(), std::basic_ifstream< _CharT, _Traits >::open(), std::basic_fstream< _CharT, _Traits >::open(), std::basic_ofstream< _CharT, _Traits >::open(), std::__detail::operator>>(), std::basic_istream< _CharT, _Traits >::putback(), std::basic_istream< _CharT, _Traits >::seekg(), std::basic_istream< _CharT, _Traits >::seekg(), std::basic_ios< _CharT, _Traits >::setstate(), and std::basic_istream< _CharT, _Traits >::unget().

🎀 `std::basic_ios< _CharT, _Traits >::copyfmt(const basic_ios< _CharT, _Traits > & __rhs)` — inherited

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:

__rhs — the source values for the copies.

Returns a reference to this object.

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().

References std::__addressof(), std::basic_ios< _CharT, _Traits >::exceptions(), std::basic_ios< _CharT, _Traits >::fill(), std::ios_base::flags(), std::ios_base::getloc(), std::ios_base::precision(), std::basic_ios< _CharT, _Traits >::tie(), std::tie(), and std::ios_base::width().

🌸 `std::basic_ios< _CharT, _Traits >::eof()` — inherited

template<typename _CharT , typename _Traits > bool std::basic_ios< _CharT,
    _Traits >::eof () const [inline],  [inherited]

Fast error checking. Returns true if the eofbit is set. Note that other iostate flags may also be set. 💖

References std::ios_base::eofbit, and std::basic_ios< _CharT, _Traits >::rdstate().

🦋 `std::basic_ios< _CharT, _Traits >::exceptions()` — inherited

template<typename _CharT , typename _Traits > iostate std::basic_ios<
    _CharT, _Traits >::exceptions () const [inline],  [inherited]

Throwing exceptions on errors. Returns the current exceptions mask. This changes nothing in the stream. See the one-argument version of exceptions(iostate) for the meaning of the return value. ✨

Referenced by std::basic_ios< _CharT, _Traits >::copyfmt().

🫶 `std::basic_ios< _CharT, _Traits >::exceptions(iostate __except)` — inherited

template<typename _CharT , typename _Traits > void std::basic_ios< _CharT,
    _Traits >::exceptions (iostate __except) [inline],  [inherited]

Throwing exceptions on errors. 💅

Parameters:

__except — the new exceptions mask.

By default, error flags are set silently. You can set an exceptions mask for each stream; if a bit in the mask becomes set in the error flags, then an exception of type std::ios_base::failure is thrown.

If the error flag is already set when the exceptions mask is added, the exception is immediately thrown. Try running the following under GCC 3.1 or later:

#include <iostream>
#include <fstream>
#include <exception>

int main()
{
    std::set_terminate (__gnu_cxx::__verbose_terminate_handler);

    std::ifstream f ("/etc/motd");

    std::cerr << "Setting badbit\n";
    f.setstate (std::ios_base::badbit);

    std::cerr << "Setting exception mask\n";
    f.exceptions (std::ios_base::badbit);
}

References std::basic_ios< _CharT, _Traits >::clear().

🌈 `std::basic_ios< _CharT, _Traits >::fail()` — inherited

template<typename _CharT , typename _Traits > bool std::basic_ios< _CharT,
    _Traits >::fail () const [inline],  [inherited]

Fast error checking. Returns true if either the badbit or the failbit is set. Checking the badbit in fail() is historical practice. Note that other iostate flags may also be set. 😭

References std::ios_base::badbit, std::ios_base::failbit, and std::basic_ios< _CharT, _Traits >::rdstate().

Referenced by std::basic_ios< _CharT, _Traits >::operator bool(), std::basic_ios< _CharT, _Traits >::operator!(), std::basic_istream< _CharT, _Traits >::seekg(), std::basic_istream< _CharT, _Traits >::seekg(), std::basic_ostream< _CharT, _Traits >::seekp(), std::basic_ostream< _CharT, _Traits >::seekp(), std::basic_istream< _CharT, _Traits >::tellg(), std::basic_ostream< _CharT, _Traits >::tellp(), and std::regex_traits< _Ch_type >::value().

👑 `std::basic_ios< _CharT, _Traits >::fill()` — inherited

template<typename _CharT , typename _Traits > char_type std::basic_ios<
    _CharT, _Traits >::fill () const [inline],  [inherited]

Retrieves the empty character. Returns the current fill character. It defaults to a space (' ') in the current locale. 🎀

References std::basic_ios< _CharT, _Traits >::widen().

Referenced by std::basic_ios< _CharT, _Traits >::copyfmt(), and std::basic_ios< _CharT, _Traits >::fill().

💖 <code>char_type std::basic_ios<_CharT, _Traits>::fill (char_type __ch) [inline], [inherited]</code> — setting the fill char

template<typename _CharT , typename _Traits > char_type std::basic_ios<
    _CharT, _Traits >::fill (char_type __ch) [inline],  [inherited]

Okay so this one sets a brand-new empty character. That's the whole vibe. 🎀

Parameters

__ch — the new character, bestie.

Returns — the previous fill character. It's giving "here's what you had before, don't say I never gave you anything". 💅

So like, the fill character is what gets 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. Iconic default honestly.

References std::basic_ios< _CharT, _Traits >::fill().

🔥 <code>fmtflags std::ios_base::flags () const [inline], [inherited]</code> — peeking at the flags

fmtflags std::ios_base::flags () const [inline],  [inherited]

Access to format flags, no cap. 🫶

Returns — the format control flags for both input and output. Both of them. She's multifaceted.

Referenced by std::basic_istream< _CharT, _Traits >::sentry::sentry(), std::basic_ostream< _CharT, _Traits >::sentry::~sentry(), std::basic_ios< _CharT, _Traits >::copyfmt(), std::num_get< _CharT, _InIter >::do_get(), std::num_get< _CharT, _InIter >::do_get(), std::num_put< _CharT, _OutIter >::do_put(), std::num_put< _CharT, _OutIter >::do_put(), std::normal_distribution< double >::operator()(), std::operator<<(), std::chrono::operator<<(), std::operator>>(), std::operator>>(), std::__detail::operator>>(), std::operator>>(), std::operator>>(), std::operator>>(), std::operator>>(), and std::operator>>().

(yes the std::operator>>() really does show up that many times, I'm not doing a bit, the list is just like that 😭)

✨ <code>fmtflags std::ios_base::flags (fmtflags __fmtfl) [inline], [inherited]</code> — setting them all at once

fmtflags std::ios_base::flags (fmtflags __fmtfl) [inline],  [inherited]

Setting new format flags, all at once, main character energy. 👑

Parameters

__fmtfl — the new flags to set.

Returns — the previous format control flags.

Heads up: this function overwrites all the format flags with __fmtfl. Not a merge, not a little update — a full overwrite. So know what you're doing, bestie. 💀

🌊 <code>basic_ostream<_CharT, _Traits> & std::basic_ostream<_CharT, _Traits>::flush () [inherited]</code> — syncing the stream buffer

template<typename _CharT , typename _Traits > basic_ostream< _CharT, _Traits
    > & std::basic_ostream< _CharT, _Traits >::flush () [inherited]

Synchronizing the stream buffer. The way that this one just does things. 🌸

Returns — *this

If rdbuf() is a null pointer, changes nothing. Nothing at all. Chill.

Otherwise, it calls rdbuf()->pubsync(), and if that returns -1, sets badbit. So there's a real chance of a bad time here. 🙈

References std::ios_base::badbit, std::ios_base::goodbit, std::basic_ios< _CharT, _Traits >::rdbuf(), and std::basic_ios< _CharT, _Traits >::setstate().

Referenced by std::flush().

🧮 <code>streamsize std::basic_istream<_CharT, _Traits>::gcount () const [inline], [inherited]</code> — character counting

template<typename _CharT , typename _Traits > streamsize std::basic_istream<
    _CharT, _Traits >::gcount () const [inline],  [inherited]

Character counting. She's literally just counting. 🎀

Returns — the number of characters extracted by the previous unformatted input function dispatched for this stream.

References std::basic_istream< _CharT, _Traits >::_M_gcount.

🍓 <code>basic_istream<_CharT, _Traits>::int_type std::basic_istream<_CharT, _Traits>::get (void) [inherited]</code> — the simple extraction

template<typename _CharT , typename _Traits > basic_istream< _CharT, _Traits
    >::int_type std::basic_istream< _CharT, _Traits >::get (void)
    [inherited]

Returns — a character, or eof().

Tries to extract a character. If none are available, sets failbit and returns traits::eof(). That's it, that's the function. 💜

References std::basic_istream< _CharT, _Traits >::_M_gcount, std::ios_base::badbit, std::ios_base::eofbit, std::ios_base::failbit, std::ios_base::goodbit, std::basic_ios< _CharT, _Traits >::rdbuf(), and std::basic_ios< _CharT, _Traits >::setstate().

Referenced by std::basic_istream< _CharT, _Traits >::get(), and std::basic_istream< _CharT, _Traits >::get().

🦋 <code>__istream_type & std::basic_istream<_CharT, _Traits>::get (__streambuf_type & __sb) [inline], [inherited]</code> — extraction into another streambuf

template<typename _CharT , typename _Traits > __istream_type &
    std::basic_istream< _CharT, _Traits >::get (__streambuf_type & __sb)
    [inline],  [inherited]

Parameters

__sb — a streambuf in which to store data.

Returns — *this

Literally just returns get(__sb,widen('\n')). A lil one-liner. She's delegating and honestly? Respect. ✨

References std::basic_istream< _CharT, _Traits >::get(), and std::basic_ios< _CharT, _Traits >::widen().

🌈 <code>basic_istream<_CharT, _Traits> & std::basic_istream<_CharT, _Traits>::get (__streambuf_type & __sb, char_type __delim) [inherited]</code> — extraction with a stop char

template<typename _CharT , typename _Traits > basic_istream< _CharT, _Traits
    > & std::basic_istream< _CharT, _Traits >::get (__streambuf_type & __sb,
    char_type __delim) [inherited]

Parameters

__sb — a streambuf in which to store data.
__delim — a 'stop' character.

Returns — *this

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. 🫶

References std::basic_istream< _CharT, _Traits >::_M_gcount, and std::ios_base::goodbit.

💅 <code>basic_istream<_CharT, _Traits> & std::basic_istream<_CharT, _Traits>::get (char_type & __c) [inherited]</code> — simple extraction, by reference

template<typename _CharT , typename _Traits > basic_istream< _CharT, _Traits
    > & std::basic_istream< _CharT, _Traits >::get (char_type & __c)
    [inherited]

Parameters

__c — the character in which to store data.

Returns — *this

Tries to extract a character and store it in __c. If none are available, sets failbit and returns traits::eof(). Same drama as before, just with somewhere to put the result. 🎀

Note — this function is not overloaded on signed char and unsigned char. Read that twice, bestie. 🔥

🌸 <code>__istream_type & std::basic_istream<_CharT, _Traits>::get (char_type * s, streamsize n) [inline], [inherited]</code> — multi-character extraction

template<typename _CharT , typename _Traits > __istream_type &
    std::basic_istream< _CharT, _Traits >::get (char_type * __s, streamsize
    __n) [inline],  [inherited]

Parameters

__s — pointer to an array.
__n — maximum number of characters to store in s.

Returns — *this

Returns get(__s,__n,widen('\n')). Another lil handoff, we love a delegation queen. 🧚

References std::basic_istream< _CharT, _Traits >::get(), and std::basic_ios< _CharT, _Traits >::widen().

👑 <code>basic_istream<_CharT, _Traits> & std::basic_istream<_CharT, _Traits>::get (char_type * s, streamsize n, char_type __delim) [inherited]</code> — the full multi-char version

template<typename _CharT , typename _Traits > basic_istream< _CharT, _Traits
    > & std::basic_istream< _CharT, _Traits >::get (char_type * __s,
    streamsize __n, char_type __delim) [inherited]

Parameters

__s — pointer to an array.
__n — maximum number of characters to store in __s.
__delim — a 'stop' character.

Returns — *this

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. Always. Non-negotiable. 💖

Note — again, this function is not overloaded on signed char and unsigned char. 😭

References std::basic_istream< _CharT, _Traits >::_M_gcount, std::ios_base::goodbit, std::basic_ios< _CharT, _Traits >::rdbuf(), and std::basic_streambuf< _CharT, _Traits >::sgetc().

📖 <code>__istream_type & std::basic_istream<_CharT, _Traits>::getline (char_type * s, streamsize n) [inline], [inherited]</code> — string extraction

template<typename _CharT , typename _Traits > __istream_type &
    std::basic_istream< _CharT, _Traits >::getline (char_type * __s,
    streamsize __n) [inline],  [inherited]

Parameters

__s — a character array in which to store the data.
__n — maximum number of characters to extract.

Returns — *this

Returns getline(__s,__n,widen('\n')). Yes bestie, another delegate. 🌟

References std::basic_istream< _CharT, _Traits >::getline(), and std::basic_ios< _CharT, _Traits >::widen().

🎀 <code>basic_istream<_CharT, _Traits> & std::basic_istream<_CharT, _Traits>::getline (char_type * s, streamsize n, char_type __delim) [inherited]</code> — the real string extraction

template<typename _CharT , typename _Traits > basic_istream< _CharT, _Traits
    > & std::basic_istream< _CharT, _Traits >::getline (char_type * __s,
    streamsize __n, char_type __delim) [inherited]

Parameters

__s — a character array in which to store the data.
__n — maximum number of characters to extract.
__delim — a 'stop' character.

Returns — *this

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. The order is load-bearing, iykyk. 🔥

the input sequence reaches end-of-file, in which case eofbit is set in the stream error state
the next character equals __delim, in which case the character is extracted (and therefore counted in gcount()) but not stored
__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. She said what she said. 💅)

In any case, a null character is stored in the next location in the array.

Referenced by std::basic_istream< _CharT, _Traits >::getline().

🧚 <code>basic_istream<char> & std::basic_istream<char>::getline (char_type * s, streamsize n, char_type __delim) [inherited]</code> — the special one

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. That's the whole thing — she's special-cased and shipped off to her own file. Main character. 👑

🌍 <code>locale std::ios_base::getloc () const [inline], [inherited]</code> — locale access

locale std::ios_base::getloc () const [inline],  [inherited]

Returns — a copy of the current locale.

If imbue(loc) has previously been called, then this function returns loc. Otherwise, it returns a copy of std::locale(), the global C++ locale. Easy. ✨

Referenced by std::basic_ios< _CharT, _Traits >::copyfmt(), std::money_put< _CharT, _OutIter >::do_put(), std::chrono::operator<<(), std::operator>>(), std::operator>>(), and std::ws().

⭐ <code>bool std::basic_ios<_CharT, _Traits>::good () const [inline], [inherited]</code> — fast error checking

template<typename _CharT , typename _Traits > bool std::basic_ios< _CharT,
    _Traits >::good () const [inline],  [inherited]

Returns — true if no error flags are set.

Literally just a wrapper around rdstate. Short, sweet, does the job. 🫶

References std::basic_ios< _CharT, _Traits >::rdstate().

Referenced by std::basic_istream< _CharT, _Traits >::sentry::sentry(), std::basic_ostream< _CharT, _Traits >::sentry::sentry(), and std::__detail::operator>>().

🙈 <code>basic_istream<_CharT, _Traits> & std::basic_istream<_CharT, _Traits>::ignore (void) [inherited]</code> — simple extraction

template<typename _CharT , typename _Traits > basic_istream< _CharT, _Traits
    > & std::basic_istream< _CharT, _Traits >::ignore (void) [inherited]

Returns — a character, or eof().

Tries to extract a character. If none are available, sets failbit and returns traits::eof(). (The docs really said "copy paste? no, copy paste with confidence" 😭)

References std::basic_istream< _CharT, _Traits >::_M_gcount, std::ios_base::eofbit, std::ios_base::goodbit, std::basic_ios< _CharT, _Traits >::rdbuf(), and std::basic_streambuf< _CharT, _Traits >::sbumpc().

🌟 <code>basic_istream<_CharT, _Traits> & std::basic_istream<_CharT, _Traits>::ignore (streamsize __n) [inherited]</code> — simple extraction, counting edition

template<typename _CharT , typename _Traits > basic_istream< _CharT, _Traits
    > & std::basic_istream< _CharT, _Traits >::ignore (streamsize __n)
    [inherited]

Returns — a character, or eof().

Tries to extract a character. If none are available, sets failbit and returns traits::eof().

References std::basic_istream< _CharT, _Traits >::_M_gcount, std::ios_base::goodbit, std::basic_ios< _CharT, _Traits >::rdbuf(), and std::basic_streambuf< _CharT, _Traits >::sgetc().

💀 <code>basic_istream<_CharT, _Traits> & std::basic_istream<_CharT, _Traits>::ignore (streamsize __n, int_type __delim) [inherited]</code>

template<typename _CharT , typename _Traits > basic_istream< _CharT, _Traits
    > & std::basic_istream< _CharT, _Traits >::ignore (streamsize __n,
    int_type __delim) [inherited]

Discarding characters.

__n — number of characters to discard 💅
__delim — a 'stop' character.

Returns: *this ✨

So what it does is extract characters and just… throw them away 🗑️ until one of these happens:

if __n != std::numeric_limits<int>::max(), __n characters are extracted
the input sequence reaches end-of-file
the next character equals __delim (and in this case, the character is extracted — it gets eaten too 🍓); note that this condition will never occur if __delim equals traits::eof()

NB: it provides three overloads instead of the single function (with defaults) that the Standard mandates — this leads to a better performing implementation, while still conforming to the Standard 👑

template<typename _CharT , typename _Traits > locale std::basic_ios< _CharT, _Traits >::imbue (const locale & __loc) [inherited] — moves to a new locale 🌍

__loc — the new locale.

Returns: the previous locale.

It calls ios_base::imbue(loc), and if a stream buffer is associated with this stream, it calls that buffer's pubimbue(loc). no cap, it's thorough 🫶

Additional l10n notes are at http://gcc.gnu.org/onlinedocs/libstdc++/manual/localization.html

References std::ios_base::imbue().

Referenced by std::chrono::operator<<().

template<typename _CharT , typename _Traits > void std::basic_ios< _CharT, _Traits >::init (basic_streambuf< _CharT, _Traits > * __sb) [protected], [inherited] — all the setup lives here 🎀

This is called from the public constructor. It is not virtual and cannot be redefined. periodt.

Referenced by std::basic_fstream< _CharT, _Traits >::basic_fstream(), std::basic_fstream< _CharT, _Traits >::basic_fstream(), std::basic_fstream< _CharT, _Traits >::basic_fstream(), std::basic_ifstream< _CharT, _Traits >::basic_ifstream(), std::basic_ifstream< _CharT, _Traits >::basic_ifstream(), std::basic_ifstream< _CharT, _Traits >::basic_ifstream(), std::basic_ios< _CharT, _Traits >::basic_ios(), std::basic_istream< _CharT, _Traits >::basic_istream(), std::basic_istringstream< _CharT, _Traits, _Alloc >::basic_istringstream(), std::basic_istringstream< _CharT, _Traits, _Alloc >::basic_istringstream(), std::basic_istringstream< _CharT, _Traits, _Alloc >::basic_istringstream(), std::basic_ofstream< _CharT, _Traits >::basic_ofstream(), std::basic_ofstream< _CharT, _Traits >::basic_ofstream(), std::basic_ofstream< _CharT, _Traits >::basic_ofstream(), std::basic_ostream< _CharT, _Traits >::basic_ostream(), std::basic_ostringstream< _CharT, _Traits, _Alloc >::basic_ostringstream(), std::basic_ostringstream< _CharT, _Traits, _Alloc >::basic_ostringstream(), std::basic_ostringstream< _CharT, _Traits, _Alloc >::basic_ostringstream(), std::basic_stringstream< _CharT, _Traits, _Alloc >::basic_stringstream(), std::basic_stringstream< _CharT, _Traits, _Alloc >::basic_stringstream(), and std::basic_stringstream< _CharT, _Traits, _Alloc >::basic_stringstream().

(like… every stream constructor ever, bestie. iconic behaviour honestly 😭)

long & std::ios_base::iword (int __ix) [inline], [inherited] — access to the integer array 🔢

__ix — index into the array.

Returns: 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, so 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 💀 like, do not clutch that reference, it will betray you.

template<typename _CharT , typename _Traits > char std::basic_ios< _CharT, _Traits >::narrow (char_type __c, char __dfault) const [inline], [inherited] — squeezes characters 🧚

__c — the character to narrow.
__dfault — the character to narrow.

Returns: the narrowed character.

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

template<typename _CharT , typename _Traits > std::basic_ios< _CharT, _Traits >::operator bool () const [inline], [explicit], [inherited] — the quick-and-easy status check ✅

This lets you write constructs such as if (!a_stream) ... and while (a_stream) ...

References std::basic_ios< _CharT, _Traits >::fail().

template<typename _CharT , typename _Traits > bool std::basic_ios< _CharT, _Traits >::operator! () const [inline], [inherited] — the quick-and-easy status check, but with a ! 🚨

This lets you write constructs such as if (!a_stream) ... and while (a_stream) ...

References std::basic_ios< _CharT, _Traits >::fail().

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.

template<typename _CharT , typename _Traits > __ostream_type & std::basic_ostream< _CharT, _Traits >::operator<< (__ostream_type &(*)(__ostream_type &) __pf) [inline], [inherited] — interface for manipulators, the sequel 🎛️✨

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.

template<typename _CharT , typename _Traits > basic_ostream< _CharT, _Traits > & std::basic_ostream< _CharT, _Traits >::operator<< (__streambuf_type * __sb) [inherited] — extracting from another streambuf 🫗

__sb — a pointer to a streambuf.

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.

template<typename _CharT , typename _Traits > __ostream_type & std::basic_ostream< _CharT, _Traits >::operator<< (bool __n) [inline], [inherited] — integer arithmetic inserter 👑

__n — a variable of builtin integral type.