std::basic_istringstream

Defined in header <sstream>

Defined in header `<sstream>`
template< class CharT, class Traits = std::char_traits<CharT> > class basic_istringstream;		(until C++11)
template< class CharT, class Traits = std::char_traits<CharT>, class Allocator = std::allocator<CharT> > class basic_istringstream;		(since C++11)

template< 
    class CharT, 
    class Traits = std::char_traits<CharT>
> class basic_istringstream;

(until C++11)

template< 
    class CharT, 
    class Traits = std::char_traits<CharT>,
    class Allocator = std::allocator<CharT>
> class basic_istringstream;

(since C++11)

The class template std::basic_istringstream implements input operations on memory (std::basic_string) based streams. It essentially wraps a raw string device implementation (std::basic_stringbuf) into a higher-level interface (std::basic_istream). The complete interface to unique std::basic_stringbuf members is provided.

Inheritance diagram.

Two specializations for common character types are also defined:

Defined in header `<sstream>`
Type	Definition
`istringstream`	`basic_istringstream<char>`
`wistringstream`	`basic_istringstream<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`
`allocator_type`	`Allocator` (since C++11)

Member functions

(constructor)	constructs the string stream (public member function)
operator= (C++11)	moves the string stream (public member function)
swap (C++11)	swaps two string streams (public member function)
rdbuf	returns the underlying raw string device object (public member function)
String operations
str	gets or sets the contents of underlying string device object (public member function)

Non-member functions

std::swap(std::basic_istringstream)

(C++11)

specializes the std::swap algorithm
(function template)

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 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

Member type	Definition
`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 void*operator bool (until C++11)(since C++11)	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 IO 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`)

Member types and constants

Type Explanation

openmode

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
`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

(typedef)

fmtflags

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 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`

(typedef)

iostate

state of the stream type

The following constants are also defined:

Constant	Explanation
`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)

seekdir

seeking direction type

The following constants are also defined:

Constant	Explanation
`beg`	the beginning of a stream
`end`	the ending of a stream
`cur`	the current position of stream position indicator

(typedef)

event

specifies event type
(enum)

event_callback

callback function type
(typedef)

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std::basic_istringstream

Member types

Member functions

String operations

Non-member functions

Inherited from std::basic_istream

Member functions

Formatted input

Unformatted input

Positioning

Miscellaneous

Member classes

Inherited from std::basic_ios

Member types

Member functions

State functions

Formatting

Miscellaneous

Inherited from std::ios_base

Member functions

Formatting

Locales

Internal extensible array

Miscellaneous

Member classes

Member types and constants