FreeBSD Manual Pages
std::basic_ios(3) C++ Standard Libary std::basic_ios(3) NAME std::basic_ios - std::basic_ios Synopsis Defined in header <ios> template< class CharT, class Traits = std::char_traits<CharT> > class basic_ios : public std::ios_base The class std::basic_ios provides facilities for interfacing with objects that have std::basic_streambuf interface. Several std::basic_ios objects can refer to one actual std::basic_streambuf object. std-basic ios-inheritance.svg Inheritance diagram Several typedefs for common character types are provided: Defined in header <ios> Type Definition std::ios std::basic_ios<char> std::wios std::basic_ios<wchar_t> Member types Member type Definition char_type CharT traits_type Traits; the program is ill-formed if Traits::char_type is not CharT. int_type Traits::int_type pos_type Traits::pos_type off_type Traits::off_type Public member functions constructor constructs the object (public member function) destructor destructs the object [virtual] (virtual public member function) operator= the copy assignment operator is deleted (public member function) State functions good checks if no error has occurred i.e. I/O operations are available (public member function) eof checks if end-of-file has been reached (public member function) fail checks if an error has occurred (public member function) bad checks if a non-recoverable error has occurred (public member function) operator! checks if an error has occurred (synonym of fail()) (public member function) operator bool checks if no error has occurred (synonym of !fail()) (public member function) rdstate returns state flags (public member function) setstate sets state flags (public member function) clear modifies state flags (public member function) Formatting copyfmt copies formatting information (public member function) fill manages the fill character (public member function) Miscellaneous exceptions manages exception mask (public member function) imbue sets the locale (public member function) rdbuf manages associated stream buffer (public member function) tie manages tied stream (public member function) narrow narrows characters (public member function) widen widens characters (public member function) Protected member functions init initializes a default-constructed std::basic_ios (protected member function) move moves from another std::basic_ios except for rdbuf (C++11) (protected member function) swap swaps with another std::basic_ios except for rdbuf (C++11) (protected member function) set_rdbuf replaces the rdbuf without clearing its error state (protected member function) 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 opera- tions (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 returns a program-wide unique integer that is safe to use as index [static] to pword() and iword() (public static member function of std::ios_base) resizes the private storage if necessary and ac- cess to the long iword element at the given index (public member function of std::ios_base) resizes the private storage if necessary and ac- cess to the void* pword 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 sets whether C++ and C I/O libraries are interop- erable [static] (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) Member types and constants Type Explanation stream open mode type The following constants are also defined: Constant Explanation app seek to the end of stream before each write binary open in binary mode openmode in open for reading out open for writing trunc discard the contents of the stream when opening ate seek to the end of stream immedi- ately after open noreplace (C++23) open in exclusive mode (typedef) formatting flags type The following constants are also defined: Constant Explanation 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 oper- ations 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 mask- ing operations generate floating point types using sci- entific notation, scientific or hex notation if combined with fixed: see std::scientific fmtflags generate floating point types using fixed notation, or fixed hex notation if combined with scientific: see std::fixed floatfield scientific | fixed. Useful for masking operations boolalpha insert and extract bool type in alphanu- meric format: see std::boolalpha generate a prefix indicating the numeric base for integer showbase output, require the currency indicator in monetary I/O: see std::showbase showpoint generate a decimal-point character uncon- ditionally 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 opera- tion: see std::unitbuf replace certain lowercase letters with their uppercase uppercase equivalents in certain output operations: see std::uppercase (typedef) state of the stream type The following constants are also defined: Constant Explanation iostate 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 (typedef) seeking direction type The following constants are also defined: seekdir Constant Explanation beg the beginning of a stream end the ending of a stream cur the current position of stream position in- dicator (typedef) event specifies event type (enum) event_callback callback function type (typedef) Notes Straightforward implementation of std::basic_ios stores only the following members (which all depend on the template parameters and thus cannot be part of std::ios_base): * the fill character (see fill()) * the tied stream pointer (see tie()) * the associated stream buffer pointer (see rdbuf()). Actual implementations vary: Microsoft Visual Studio stores just those three members. LLVM libc++ stores 1 less member: it maintains the rdbuf pointer as a void* member of ios_base. GNU libstdc++ stores 4 additional members: three cached facets and a flag to indicate that fill was initialized. http://cppreference.com 2024.06.10 std::basic_ios(3)
NAME | Synopsis | Member types | Public member functions | State functions | Formatting | Miscellaneous | Protected member functions | Member functions | Formatting | Locales | Internal extensible array | Miscellaneous | Member classes | Member types and constants | Notes
Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=std::ios&sektion=3&manpath=FreeBSD+Ports+15.1.quarterly>