Difference between revisions of "cpp/io/basic stringstream"

Latest revision as of 11:51, 13 September 2023

Defined in header `<sstream>`
template< class CharT, class Traits = std::char_traits<CharT>, class Allocator = std::allocator<CharT> > class basic_stringstream : public basic_iostream<CharT, Traits>;

The class template std::basic_stringstream implements input and output operations on string based streams. It effectively stores an instance of std::basic_string and performs the input and output operations on it.

At the low level, the class essentially wraps a raw string device implementation of std::basic_stringbuf into a higher-level interface of std::basic_iostream. The complete interface to unique std::basic_stringbuf members is provided.

Inheritance diagram

Several typedefs for common character types are provided:

Defined in header `<sstream>`
Type	Definition
`std::stringstream`	std::basic_stringstream<char>
`std::wstringstream`	std::basic_stringstream<wchar_t>

[edit] Member types

Member type	Definition
`char_type`	`CharT`[edit]
`traits_type`	`Traits`; the program is ill-formed if `Traits::char_type` is not `CharT`.[edit]
`int_type`	`Traits::int_type`[edit]
`pos_type`	`Traits::pos_type`[edit]
`off_type`	`Traits::off_type`[edit]
`allocator_type`	`Allocator`[edit]

[edit] Exposition-only members

Name	Definition
`sb`	the std::basic_stringbuf<CharT, Traits, Allocator> used as the underlying buffer (exposition-only member object*)

[edit] Member functions

(constructor)	constructs the string stream (public member function) [edit]
operator= (C++11)	moves the string stream (public member function) [edit]
swap (C++11)	swaps two string streams (public member function) [edit]
rdbuf	returns the underlying raw string device object (public member function) [edit]
String operations
str	gets or sets the contents of underlying string device object (public member function) [edit]
view (C++20)	obtains a view over the contents of underlying string device object (public member function) [edit]

[edit] Non-member functions

std::swap(std::basic_istringstream)

(C++11)

specializes the std::swap algorithm
(function template) [edit]

Inherited from std::basic_istream

Member functions

Formatted input
operator>>	extracts formatted data (public member function of `std::basic_istream<CharT,Traits>`) [edit]
Unformatted input
get	extracts characters (public member function of `std::basic_istream<CharT,Traits>`) [edit]
peek	reads the next character without extracting it (public member function of `std::basic_istream<CharT,Traits>`) [edit]
unget	unextracts a character (public member function of `std::basic_istream<CharT,Traits>`) [edit]
putback	puts a character into input stream (public member function of `std::basic_istream<CharT,Traits>`) [edit]
getline	extracts characters until the given character is found (public member function of `std::basic_istream<CharT,Traits>`) [edit]
ignore	extracts and discards characters until the given character is found (public member function of `std::basic_istream<CharT,Traits>`) [edit]
read	extracts blocks of characters (public member function of `std::basic_istream<CharT,Traits>`) [edit]
readsome	extracts already available blocks of characters (public member function of `std::basic_istream<CharT,Traits>`) [edit]
gcount	returns number of characters extracted by last unformatted input operation (public member function of `std::basic_istream<CharT,Traits>`) [edit]
Positioning
tellg	returns the input position indicator (public member function of `std::basic_istream<CharT,Traits>`) [edit]
seekg	sets the input position indicator (public member function of `std::basic_istream<CharT,Traits>`) [edit]
Miscellaneous
sync	synchronizes with the underlying storage device (public member function of `std::basic_istream<CharT,Traits>`) [edit]

Member classes

sentry

implements basic logic for preparation of the stream for input operations
(public member class of std::basic_istream<CharT,Traits>) [edit]

Inherited from std::basic_ostream

Member functions

Formatted output
operator<<	inserts formatted data (public member function of `std::basic_ostream<CharT,Traits>`) [edit]
Unformatted output
put	inserts a character (public member function of `std::basic_ostream<CharT,Traits>`) [edit]
write	inserts blocks of characters (public member function of `std::basic_ostream<CharT,Traits>`) [edit]
Positioning
tellp	returns the output position indicator (public member function of `std::basic_ostream<CharT,Traits>`) [edit]
seekp	sets the output position indicator (public member function of `std::basic_ostream<CharT,Traits>`) [edit]
Miscellaneous
flush	synchronizes with the underlying storage device (public member function of `std::basic_ostream<CharT,Traits>`) [edit]

Member classes

sentry

implements basic logic for preparation of the stream for output operations
(public member class of std::basic_ostream<CharT,Traits>) [edit]

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>`) [edit]
eof	checks if end-of-file has been reached (public member function of `std::basic_ios<CharT,Traits>`) [edit]
fail	checks if an error has occurred (public member function of `std::basic_ios<CharT,Traits>`) [edit]
bad	checks if a non-recoverable error has occurred (public member function of `std::basic_ios<CharT,Traits>`) [edit]
operator!	checks if an error has occurred (synonym of fail()) (public member function of `std::basic_ios<CharT,Traits>`) [edit]
operator bool	checks if no error has occurred (synonym of `!`fail()) (public member function of `std::basic_ios<CharT,Traits>`) [edit]
rdstate	returns state flags (public member function of `std::basic_ios<CharT,Traits>`) [edit]
setstate	sets state flags (public member function of `std::basic_ios<CharT,Traits>`) [edit]
clear	modifies state flags (public member function of `std::basic_ios<CharT,Traits>`) [edit]
Formatting
copyfmt	copies formatting information (public member function of `std::basic_ios<CharT,Traits>`) [edit]
fill	manages the fill character (public member function of `std::basic_ios<CharT,Traits>`) [edit]
Miscellaneous
exceptions	manages exception mask (public member function of `std::basic_ios<CharT,Traits>`) [edit]
imbue	sets the locale (public member function of `std::basic_ios<CharT,Traits>`) [edit]
rdbuf	manages associated stream buffer (public member function of `std::basic_ios<CharT,Traits>`) [edit]
tie	manages tied stream (public member function of `std::basic_ios<CharT,Traits>`) [edit]
narrow	narrows characters (public member function of `std::basic_ios<CharT,Traits>`) [edit]
widen	widens characters (public member function of `std::basic_ios<CharT,Traits>`) [edit]

Inherited from std::ios_base

Member functions

Formatting
flags	manages format flags (public member function of `std::ios_base`) [edit]
setf	sets specific format flag (public member function of `std::ios_base`) [edit]
unsetf	clears specific format flag (public member function of `std::ios_base`) [edit]
precision	manages decimal precision of floating point operations (public member function of `std::ios_base`) [edit]
width	manages field width (public member function of `std::ios_base`) [edit]
Locales
imbue	sets locale (public member function of `std::ios_base`) [edit]
getloc	returns current locale (public member function of `std::ios_base`) [edit]
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`) [edit]
iword	resizes the private storage if necessary and access to the long element at the given index (public member function of `std::ios_base`) [edit]
pword	resizes the private storage if necessary and access to the void* element at the given index (public member function of `std::ios_base`) [edit]
Miscellaneous
register_callback	registers event callback function (public member function of `std::ios_base`) [edit]
sync_with_stdio [static]	sets whether C++ and C I/O libraries are interoperable (public static member function of `std::ios_base`) [edit]
Member classes
failure	stream exception (public member class of `std::ios_base`) [edit]
Init	initializes standard stream objects (public member class of `std::ios_base`) [edit]

Member types and constants

Type Explanation

openmode

stream open mode type

The following constants are also defined:

Constant	Explanation[edit]
`app`	seek to the end of stream before each write[edit]
`binary`	open in binary mode[edit]
`in`	open for reading[edit]
`out`	open for writing[edit]
`trunc`	discard the contents of the stream when opening[edit]
`ate`	seek to the end of stream immediately after open[edit]
`noreplace` (C++23)	open in exclusive mode[edit]

(typedef) [edit]

fmtflags

formatting flags type

The following constants are also defined:

Constant	Explanation[edit]
`dec`	use decimal base for integer I/O: see std::dec[edit]
`oct`	use octal base for integer I/O: see std::oct[edit]
`hex`	use hexadecimal base for integer I/O: see std::hex[edit]
`basefield`	dec \| oct \| hex. Useful for masking operations[edit]
`left`	left adjustment (adds fill characters to the right): see std::left[edit]
`right`	right adjustment (adds fill characters to the left): see std::right[edit]
`internal`	internal adjustment (adds fill characters to the internal designated point): see std::internal[edit]
`adjustfield`	left \| right \| internal. Useful for masking operations[edit]
`scientific`	generate floating point types using scientific notation, or hex notation if combined with fixed: see std::scientific[edit]
`fixed`	generate floating point types using fixed notation, or hex notation if combined with scientific: see std::fixed[edit]
`floatfield`	scientific \| fixed. Useful for masking operations[edit]
`boolalpha`	insert and extract bool type in alphanumeric format: see std::boolalpha[edit]
`showbase`	generate a prefix indicating the numeric base for integer output, require the currency indicator in monetary I/O: see std::showbase[edit]
`showpoint`	generate a decimal-point character unconditionally for floating-point number output: see std::showpoint[edit]
`showpos`	generate a + character for non-negative numeric output: see std::showpos[edit]
`skipws`	skip leading whitespace before certain input operations: see std::skipws[edit]
`unitbuf`	flush the output after each output operation: see std::unitbuf[edit]
`uppercase`	replace certain lowercase letters with their uppercase equivalents in certain output operations: see std::uppercase[edit]

(typedef) [edit]

iostate

state of the stream type

The following constants are also defined:

Constant	Explanation[edit]
`goodbit`	no error[edit]
`badbit`	irrecoverable stream error[edit]
`failbit`	input/output operation failed (formatting or extraction error)[edit]
`eofbit`	associated input sequence has reached end-of-file[edit]

(typedef) [edit]

seekdir

seeking direction type

The following constants are also defined:

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

(typedef) [edit]

event

specifies event type
(enum) [edit]

event_callback

callback function type
(typedef) [edit]

@@ Line 1: / Line 1: @@
 {{cpp/title|basic_stringstream}}
-{{cpp/io/basic_stringstream/sidebar}}
+{{cpp/io/basic_stringstream/navbar}}
-{{ddcl list begin}}
+{{ddcl|header=sstream|1=
-{{ddcl list header | sstream}}
-{{ddcl list item | notes={{mark pre c++11 version}} | 1=
-template<
-    class CharT,
-    class Traits = std::char_traits<CharT>
-> class basic_stringstream;
-}}
-{{ddcl list item | notes={{mark since c++11}} | 1=
 template<
      class CharT,
      class Traits = std::char_traits<CharT>,
      class Allocator = std::allocator<CharT>
-> class basic_stringstream;
+> class basic_stringstream
+    : public basic_iostream<CharT, Traits>;
 }}
-{{ddcl list end}}
-The class template {{tt|basic_stringstream}} implements input/output operations on memory ({{cpp|std::basic_string}}) based streams. It essentially wraps a raw string device implementation ({{rlpt|basic_stringbuf}}) into a higher-level interface ({{rlpt|basic_iostream}}). The complete interface to unique {{tt|basic_stringbuf}} members is provided.
+The class template {{tt|std::basic_stringstream}} implements input and output operations on string based streams. It effectively stores an instance of {{lc|std::basic_string}} and performs the input and output operations on it.
-{{inheritance diagram|image=std-basic_stringstream-inheritance.png|map=
+At the low level, the class essentially wraps a raw string device implementation of {{lc|std::basic_stringbuf}} into a higher-level interface of {{lc|std::basic_iostream}}. The complete interface to unique {{lc|std::basic_stringbuf}} members is provided.
-rect 5 33 107 66 [[cpp/io/ios_base]]
-rect 142 31 263 69 [[cpp/io/basic_ios]]
-rect 297 4 418 42 [[cpp/io/basic_istream]]
-rect 297 58 418 96 [[cpp/io/basic_ostream]]
-rect 452 31 573 69 [[cpp/io/basic_iostream]]
-}}
-Two specializations for common character types are also defined:
+{{inheritance diagram/std-basic_stringstream}}
-{{tdcl list begin}}
+{{cpp/basic char typedefs|stringstream|sstream}}
-{{tdcl list header | sstream}}
-{{tdcl list hitem | Type | Definition}}
-{{tdcl list item | {{tt|stringstream}} | {{cpp|basic_stringstream<char>}}}}
-{{tdcl list item | {{tt|wstringstream}} | {{cpp|basic_stringstream<wchar_t>}}}}
-{{tdcl list end}}
 ===Member types===
-{{tdcl list begin}}
+{{dsc begin}}
-{{tdcl list hitem | Member type | Definition}}
+{{dsc hitem|Member type|Definition}}
-{{tdcl list template | cpp/io/tdcl list char_type}}
+{{dsc inc|cpp/io/dsc char_type}}
-{{tdcl list template | cpp/io/tdcl list traits_type}}
+{{dsc inc|cpp/io/dsc traits_type}}
-{{tdcl list template | cpp/io/tdcl list int_type}}
+{{dsc inc|cpp/io/dsc int_type}}
-{{tdcl list template | cpp/io/tdcl list pos_type}}
+{{dsc inc|cpp/io/dsc pos_type}}
-{{tdcl list template | cpp/io/tdcl list off_type}}
+{{dsc inc|cpp/io/dsc off_type}}
-{{tdcl list template | cpp/io/tdcl list allocator_type}}
+{{dsc inc|cpp/io/dsc allocator_type}}
-{{tdcl list end}}
+{{dsc end}}
+===Exposition-only members===
+{{dsc begin}}
+{{dsc hitem|Name|Definition}}
+{{dsc expos mem obj|sb|the {{c/core|std::basic_stringbuf<CharT, Traits, Allocator>}} used as the underlying buffer}}
+{{dsc end}}
 ===Member functions===
-{{dcl list begin}}
+{{dsc begin}}
-{{dcl list template | cpp/io/basic_stringstream/dcl list constructor | basic_stringstream}}
+{{dsc inc|cpp/io/basic_stringstream/dsc constructor|basic_stringstream}}
-{{dcl list template | cpp/io/basic_stringstream/dcl list operator{{=}} | basic_stringstream}}
+{{dsc inc|cpp/io/basic_stringstream/dsc operator{{=}}|basic_stringstream}}
-{{dcl list template | cpp/io/basic_stringstream/dcl list swap | basic_stringstream}}
+{{dsc inc|cpp/io/basic_stringstream/dsc swap|basic_stringstream}}
-{{dcl list template | cpp/io/basic_stringstream/dcl list rdbuf | basic_stringstream}}
+{{dsc inc|cpp/io/basic_stringstream/dsc rdbuf|basic_stringstream}}
-{{dcl list h2 | String operations }}
+{{dsc h2|String operations}}
-{{dcl list template | cpp/io/basic_stringstream/dcl list str | basic_stringstream}}
+{{dsc inc|cpp/io/basic_stringstream/dsc str|basic_stringstream}}
-{{dcl list end}}
+{{dsc inc|cpp/io/basic_stringstream/dsc view|basic_stringstream}}
+{{dsc end}}
+===Non-member functions===
+{{dsc begin}}
+{{dsc inc|cpp/io/basic_stringstream/dsc swap2|basic_istringstream}}
+{{dsc end}}
 {{cpp/io/basic_istream/inherit}}
@@ Line 63: / Line 56: @@
 {{cpp/io/basic_ios/inherit}}
 {{cpp/io/ios_base/inherit}}
+{{langlinks|de|es|fr|it|ja|pt|ru|zh}}

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Print functions (C++23)
C-style I/O
Buffers
basic_streambuf
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Synchronized Output
basic_osyncstream (C++20)
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streamoff
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Error category interface
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Member functions
basic_stringstream::basic_stringstream
basic_stringstream::operator=
basic_stringstream::swap (C++11)
basic_stringstream::rdbuf
String operations
basic_stringstream::str
basic_stringstream::view (C++20)
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Difference between revisions of "cpp/io/basic stringstream"

Latest revision as of 11:51, 13 September 2023

Contents

[edit] Member types

[edit] Exposition-only members

[edit] Member functions

String operations

[edit] Non-member functions

Inherited from std::basic_istream

Member functions

Formatted input

Unformatted input

Positioning

Miscellaneous

Member classes

Inherited from std::basic_ostream

Member functions

Formatted output

Unformatted output

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

Navigation

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