std::istrstream(3)

std::istrstream(3) 💅

okay so bestie, this is the std::istrstream(3) page from the C++ Standard Libary manual — yes, that’s the spelling up top, we’re not fixing it, it’s iconic — and the name is literally just std::istrstream. no cap.

🌸 NAME 🌸

std::istrstream — std::istrstream. that’s it. that’s the name. slay.

✨ Synopsis ✨

Defined in header <strstream>:

class istrstream : public std::istream  (deprecated in C++98)
                                        (removed in C++26)

The class istrstream implements input operations on array-backed streams. It essentially wraps a raw array I/O device implementation (std::strstreambuf) into the higher-level interface of std::basic_istream.

The typical implementation of istrstream holds only one non-derived data member: an object of type std::strstreambuf.

💅 Notes 💅

istrstream has been deprecated since C++98 and removed since C++26.

std::istringstream, std::ispanstream (since C++23), and boost::iostreams::array_source are the recommended replacements.

🫶 Member functions 🫶

• constructor — constructs an istrstream object, optionally allocating the buffer (public member function)
• destructor — destructs an istrstream object, optionally deallocating the buffer
• [virtual] — (virtual public member function)
• rdbuf — obtains a pointer to the associated strstreambuf (public member function)
• str — accesses the output buffer (public member function)

🦋 Inherited from std::basic_istream 🦋

✨ Member functions ✨

Formatted input

• operator>> — extracts formatted data (public member function of std::basic_istream<CharT,Traits>)

Unformatted input

• get — extracts characters (public member function of std::basic_istream<CharT,Traits>)
• peek — reads the next character without extracting it (public member function of std::basic_istream<CharT,Traits>)
• unget — unextracts a character (public member function of std::basic_istream<CharT,Traits>)
• putback — puts a character into input stream (public member function of std::basic_istream<CharT,Traits>)
• getline — extracts characters until the given character is found (public member function of std::basic_istream<CharT,Traits>)
• ignore — extracts and discards characters until the given character is found (public member function of std::basic_istream<CharT,Traits>)
• read — extracts blocks of characters (public member function of std::basic_istream<CharT,Traits>)
• readsome — extracts already available blocks of characters (public member function of std::basic_istream<CharT,Traits>)
• gcount — returns number of characters extracted by last unformatted input operation (public member function of std::basic_istream<CharT,Traits>)

Positioning

• tellg — returns the input position indicator (public member function of std::basic_istream<CharT,Traits>)
• seekg — sets the input position indicator (public member function of std::basic_istream<CharT,Traits>)

Miscellaneous

• sync — synchronizes with the underlying storage device (public member function of std::basic_istream<CharT,Traits>)

🎀 Member classes 🎀

• sentry — implements basic logic for preparation of the stream for input operations (public member class of std::basic_istream<CharT,Traits>)

🌈 Inherited from std::basic_ios 🌈

💖 Member types 💖

• char_type — CharT
• traits_type — Traits
• int_type — Traits::int_type
• pos_type — Traits::pos_type
• off_type — Traits::off_type

💜 Member functions 💜

State functions

• good — checks if no error has occurred i.e. I/O operations are available (public member function of std::basic_ios<CharT,Traits>)
• eof — checks if end-of-file has been reached (public member function of std::basic_ios<CharT,Traits>)
• fail — checks if an error has occurred (public member function of std::basic_ios<CharT,Traits>)
• bad — checks if a non-recoverable error has occurred (public member function of std::basic_ios<CharT,Traits>)
• operator! — checks if an error has occurred (synonym of fail()) (public member function of std::basic_ios<CharT,Traits>)
• operator bool — checks if no error has occurred (synonym of !fail()) (public member function of std::basic_ios<CharT,Traits>)
• rdstate — returns state flags (public member function of std::basic_ios<CharT,Traits>)
• setstate — sets state flags (public member function of std::basic_ios<CharT,Traits>)
• clear — modifies state flags (public member function of std::basic_ios<CharT,Traits>)

Formatting

• copyfmt — copies formatting information (public member function of std::basic_ios<CharT,Traits>)
• fill — manages the fill character (public member function of std::basic_ios<CharT,Traits>)

Miscellaneous

• exceptions — manages exception mask (public member function of std::basic_ios<CharT,Traits>)
• imbue — sets the locale (public member function of std::basic_ios<CharT,Traits>)
• rdbuf — manages associated stream buffer (public member function of std::basic_ios<CharT,Traits>)
• tie — manages tied stream (public member function of std::basic_ios<CharT,Traits>)
• narrow — narrows characters (public member function of std::basic_ios<CharT,Traits>)
• widen — widens characters (public member function of std::basic_ios<CharT,Traits>)

🌟 Inherited from std::ios_base 🌟

🧚 Member functions 🧚

Formatting

• flags — manages format flags (public member function of std::ios_base)
• setf — sets specific format flag (public member function of std::ios_base)
• unsetf — clears specific format flag (public member function of std::ios_base)
• precision — manages decimal precision of floating point operations (public member function of std::ios_base)
• width — manages field width (public member function of std::ios_base)

Locales

• imbue — sets locale (public member function of std::ios_base)
• getloc — returns current locale (public member function of std::ios_base)

Internal extensible array

• xalloc [static] — returns a program-wide unique integer that is safe to use as index to pword() and iword() (public static member function of std::ios_base)
• iword — resizes the private storage if necessary and access to the long element at the given index (public member function of std::ios_base)
• pword — resizes the private storage if necessary and access to the void* element at the given index (public member function of std::ios_base)

Miscellaneous

• register_callback — registers event callback function (public member function of std::ios_base)
• sync_with_stdio [static] — sets whether C++ and C I/O libraries are interoperable (public static member function of std::ios_base)

👑 Member classes 👑

• failure — stream exception (public member class of std::ios_base)
• Init — initializes standard stream objects (public member class of std::ios_base)

okay so here’s the member-types-and-constants part, bestie — it’s giving “keep this tab open forever” energy, and honestly same 💖

• openmode — stream open mode type (typedef). The following constants are also defined:
  • app — seek to the end of stream before each write
  • binary — open in binary mode
  • in — open for reading
  • out — open for writing
  • trunc — discard the contents of the stream when opening
  • ate — seek to the end of stream immediately after open
  • noreplace (C++23) — open in exclusive mode
• fmtflags — formatting flags type (typedef). The following constants are also defined:
  • dec — use decimal base for integer I/O: see std::dec
  • oct — use octal base for integer I/O: see std::oct
  • hex — use hexadecimal base for integer I/O: see std::hex
  • basefield — dec | oct | hex. Useful for masking operations
  • left — left adjustment (adds fill characters to the right): see std::left
  • right — right adjustment (adds fill characters to the left): see std::right
  • internal — internal adjustment (adds fill characters to the internal designated point): see std::internal
  • adjustfield — left | right | internal. Useful for masking operations
  • scientific — generate floating point types using scientific notation, or hex notation if combined with fixed: see std::scientific
  • fixed — generate floating point types using fixed notation, or hex notation if combined with scientific: see std::fixed
  • floatfield — scientific | fixed. Useful for masking operations
  • boolalpha — insert and extract bool type in alphanumeric format: see std::boolalpha
  • showbase — generate a prefix indicating the numeric base for integer output, require the currency indicator in monetary I/O: see std::showbase
  • showpoint — generate a decimal-point character unconditionally for floating-point number output: see std::showpoint
  • showpos — generate a + character for non-negative numeric output: see std::showpos
  • skipws — skip leading whitespace before certain input operations: see std::skipws
  • unitbuf — flush the output after each output operation: see std::unitbuf
  • uppercase — replace certain lowercase letters with their uppercase equivalents in certain output operations: see std::uppercase
• iostate — state of the stream type (typedef). The following constants are also defined:
  • goodbit — no error
  • badbit — irrecoverable stream error
  • failbit — input/output operation failed (formatting or extraction error)
  • eofbit — associated input sequence has reached end-of-file
• seekdir — seeking direction type (typedef). The following constants are also defined:
  • beg — the beginning of a stream
  • end — the ending of a stream
  • cur — the current position of stream position indicator
• event — specifies event type (enum)
• event_callback — callback function type (typedef)

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okay that’s the whole reference-table moment, bestie — you ate, no crumbs 💅✨ The footer energy is cppreference.com, version/date 2024.06.10, for std::istrstream(3) — mwah, go slay some streams 🎀🦋