Difference between revisions of "cpp/io/strstream"

Latest revision as of 07:11, 6 April 2024

Defined in header `<strstream>`
class strstream : public std::iostream		(deprecated in C++98) (removed in C++26)

The class strstream implements input and output 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_iostream.

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

[edit] Notes

After any call to str(), a call to freeze(false) is required to allow the destructor to deallocate the buffer as necessary.

Before any call to str() that uses the result as a C-string, the buffer must be null-terminated, typically with std::ends.

strstream has been deprecated since C++98 and removed since C++26. std::stringstream, std::spanstream(since C++23), and boost::iostreams::array are the recommended replacements.

[edit] Member functions

(constructor)	constructs a `strstream` object, optionally allocating the buffer (public member function) [edit]
(destructor) [virtual]	destructs a `strstream` object, optionally deallocating the buffer (virtual public member function) [edit]
rdbuf	obtains a pointer to the associated `strstreambuf` (public member function) [edit]
str	accesses the output buffer (public member function) [edit]
freeze	disables/enables automatic reallocation (public member function) [edit]
pcount	obtains the number of characters written (public member function) [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|strstream}}
 {{cpp/io/strstream/navbar}}
-{{dcl begin}}
+{{ddcl|header=strstream|deprecated=c++98|removed=c++26|1=
-{{dcl header|strstream}}
-{{dcl | notes={{mark deprecated}} | 1=
 class strstream : public std::iostream
 }}
-{{dcl end}}
-The class {{tt|strstream}} implements input and output operations on array-backed streams. It essentially wraps a raw array I/O device implementation ({{c|std::strstreambuf}}) into the higher-level interface of {{lc|std::basic_iostream}}.
+The class {{tt|strstream}} implements input and output operations on array-backed streams. It essentially wraps a raw array I/O device implementation ({{lc|std::strstreambuf}}) into the higher-level interface of {{lc|std::basic_iostream}}.
-The typical implementation of {{tt|strstream}} holds only one non-derived data member: an object of type {{c|std::strstreambuf}}.
+The typical implementation of {{tt|strstream}} holds only one non-derived data member: an object of type {{lc|std::strstreambuf}}.
 ===Notes===
-After any call to {{tt|str()}}, a call to {{tt|freeze(false)}} is required to allow the destructor to deallocate the buffer as necessary.
+After any call to {{lc|str()}}, a call to {{lc|freeze()|freeze(false)}} is required to allow the destructor to deallocate the buffer as necessary.
-Before any call to {{tt|str()}} that uses the result as a C string, the buffer must be null-terminated, typically with {{lc|std::ends}}.
+Before any call to {{lc|str()}} that uses the result as a C-string, the buffer must be null-terminated, typically with {{lc|std::ends}}.
-{{tt|strstream}} has been deprecated since C++98, {{lc|std::stringstream}} and [http://www.boost.org/doc/libs/release/libs/iostreams/doc/classes/array.html#array boost::iostreams::array] are the recommended replacements.
+{{tt|strstream}} has been deprecated since C++98 and removed since C++26. {{lc|std::stringstream}}{{rev inl|since=c++23|, {{ltt|cpp/io/basic_spanstream|std::spanstream}}}}, and [https://www.boost.org/doc/libs/release/libs/iostreams/doc/classes/array.html#array {{tt|boost::iostreams::array}}] are the recommended replacements.
 ===Member functions===
 {{dsc begin}}
-{{dsc inc | cpp/io/strstream/dsc constructor | strstream}}
+{{dsc inc|cpp/io/strstream/dsc constructor|strstream}}
-{{dsc inc | cpp/io/strstream/dsc destructor | strstream}}
+{{dsc inc|cpp/io/strstream/dsc destructor|strstream}}
-{{dsc inc | cpp/io/strstream/dsc rdbuf | strstream}}
+{{dsc inc|cpp/io/strstream/dsc rdbuf|strstream}}
-{{dsc inc | cpp/io/strstream/dsc str | strstream}}
+{{dsc inc|cpp/io/strstream/dsc str|strstream}}
-{{dsc inc | cpp/io/strstream/dsc freeze | strstream}}
+{{dsc inc|cpp/io/strstream/dsc freeze|strstream}}
-{{dsc inc | cpp/io/strstream/dsc pcount | strstream}}
+{{dsc inc|cpp/io/strstream/dsc pcount|strstream}}
 {{dsc end}}
@@ Line 34: / Line 31: @@
 {{cpp/io/ios_base/inherit}}
-[[de:cpp/io/strstream]]
+{{langlinks|de|es|fr|it|ja|pt|ru|zh}}
-[[es:cpp/io/strstream]]
-[[fr:cpp/io/strstream]]
-[[it:cpp/io/strstream]]
-[[ja:cpp/io/strstream]]
-[[pt:cpp/io/strstream]]
-[[ru:cpp/io/strstream]]
-[[zh:cpp/io/strstream]]

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Synchronized Output
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Error category interface
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Member functions
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strstream::rdbuf
strstream::str
strstream::pcount
strstream::freeze

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Difference between revisions of "cpp/io/strstream"

Latest revision as of 07:11, 6 April 2024

Contents

[edit] Notes

[edit] 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

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