std::basic_ios<CharT,Traits>::basic_ios

 

C++

Compiler support

Freestanding and hosted

Language

Standard library

Standard library headers

Named requirements

Feature test macros (C++20)

Language support library

Concepts library (C++20)

Metaprogramming library (C++11)

Diagnostics library

General utilities library

Strings library

Containers library

Iterators library

Ranges library (C++20)

Algorithms library

Numerics library

Localizations library

Input/output library

Filesystem library (C++17)

Regular expressions library (C++11)

Concurrency support library (C++11)

Execution support library (C++26)

Technical specifications

Symbols index

External libraries

 

Input/output library

I/O manipulators

Print functions (C++23)

C-style I/O

Buffers

basic_streambuf

basic_filebuf

basic_stringbuf

basic_spanbuf (C++23)

strstreambuf (C++98/26*)

basic_syncbuf (C++20)

Streams

Abstractions

ios_base

basic_ios

basic_istream

basic_ostream

basic_iostream

File I/O

basic_ifstream

basic_ofstream

basic_fstream

String I/O

basic_istringstream

basic_ostringstream

basic_stringstream

Array I/O

basic_ispanstream (C++23)

basic_ospanstream (C++23)

basic_spanstream (C++23)

istrstream (C++98/26*)

ostrstream (C++98/26*)

strstream (C++98/26*)

Synchronized Output

basic_osyncstream (C++20)

Types

streamoff

streamsize

fpos

Error category interface

iostream_category (C++11)

io_errc (C++11)

 

std::basic_ios

Member functions

basic_ios::basic_ios

basic_ios::~basic_ios

State functions

basic_ios::good

basic_ios::eof

basic_ios::fail

basic_ios::bad

basic_ios::operator!

basic_ios::operator bool

basic_ios::rdstate

basic_ios::setstate

basic_ios::clear

Formatting

basic_ios::copyfmt

basic_ios::fill

Miscellaneous

basic_ios::exceptions

basic_ios::imbue

basic_ios::rdbuf

basic_ios::tie

basic_ios::narrow

basic_ios::widen

Protected member functions

basic_ios::init

basic_ios::move (C++11)

basic_ios::swap (C++11)

basic_ios::set_rdbuf (C++11)

 

protected: basic_ios();	(1)
public: explicit basic_ios( std::basic_streambuf<CharT, Traits>* sb );	(2)
	(3)
private: basic_ios( const basic_ios& );			(until C++11)
public: basic_ios( const basic_ios& ) = delete;			(since C++11)

Constructs a new std::basic_ios object.

1) Default constructor. The internal state is not initialized. init() must be called before the first use of the object or before destructor, otherwise the behavior is undefined.

2) Initializes the internal state by calling init(sb). The associated stream buffer is set to sb.

3) The copy constructor is declared private and not defined(until C++11)explicitly defined as deleted(since C++11): I/O streams are not CopyConstructible.

Parameters

sb

-

stream buffer to associate to

Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

DR	Applied to	Behavior as published	Correct behavior
LWG 1249	C++98	internal state did not need to be initialized before first use	also needs to be initialized