Input/output library
Buffers
Streams
Abstractions
File I/O
String I/O
Array I/O
Synchronized Output
Types
Error category interface
(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 .
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
constructs a
strstream
object, optionally allocating the buffer
(public member function) [edit]
destructs a
strstream
object, optionally deallocating the buffer
(virtual public member function) [edit]
obtains a pointer to the associated
strstreambuf
(public member function) [edit]
accesses the output buffer
(public member function) [edit]
disables/enables automatic reallocation
(public member function) [edit]
obtains the number of characters written
(public member function) [edit]
Member functions
Formatted input
extracts formatted data
(public member function of std::basic_istream<CharT,Traits>
) [edit]
Unformatted input
extracts characters
(public member function of std::basic_istream<CharT,Traits>
) [edit]
reads the next character without extracting it
(public member function of std::basic_istream<CharT,Traits>
) [edit]
unextracts a character
(public member function of std::basic_istream<CharT,Traits>
) [edit]
puts a character into input stream
(public member function of std::basic_istream<CharT,Traits>
) [edit]
extracts characters until the given character is found
(public member function of std::basic_istream<CharT,Traits>
) [edit]
extracts and discards characters until the given character is found
(public member function of std::basic_istream<CharT,Traits>
) [edit]
extracts blocks of characters
(public member function of std::basic_istream<CharT,Traits>
) [edit]
extracts already available blocks of characters
(public member function of std::basic_istream<CharT,Traits>
) [edit]
returns number of characters extracted by last unformatted input operation
(public member function of std::basic_istream<CharT,Traits>
) [edit]
Positioning
returns the input position indicator
(public member function of std::basic_istream<CharT,Traits>
) [edit]
sets the input position indicator
(public member function of std::basic_istream<CharT,Traits>
) [edit]
Miscellaneous
synchronizes with the underlying storage device
(public member function of std::basic_istream<CharT,Traits>
) [edit]
Member classes
implements basic logic for preparation of the stream for input operations
(public member class of std::basic_istream<CharT,Traits>
) [edit]
Member functions
Formatted output
inserts formatted data
(public member function of std::basic_ostream<CharT,Traits>
) [edit]
Unformatted output
inserts a character
(public member function of std::basic_ostream<CharT,Traits>
) [edit]
inserts blocks of characters
(public member function of std::basic_ostream<CharT,Traits>
) [edit]
Positioning
returns the output position indicator
(public member function of std::basic_ostream<CharT,Traits>
) [edit]
sets the output position indicator
(public member function of std::basic_ostream<CharT,Traits>
) [edit]
Miscellaneous
synchronizes with the underlying storage device
(public member function of std::basic_ostream<CharT,Traits>
) [edit]
Member classes
implements basic logic for preparation of the stream for output operations
(public member class of std::basic_ostream<CharT,Traits>
) [edit]
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
checks if no error has occurred i.e. I/O operations are available
(public member function of std::basic_ios<CharT,Traits>
) [edit]
checks if end-of-file has been reached
(public member function of std::basic_ios<CharT,Traits>
) [edit]
checks if an error has occurred
(public member function of std::basic_ios<CharT,Traits>
) [edit]
checks if a non-recoverable error has occurred
(public member function of std::basic_ios<CharT,Traits>
) [edit]
checks if an error has occurred (synonym of
fail() )
(public member function of std::basic_ios<CharT,Traits>
) [edit]
checks if no error has occurred (synonym of
!
fail() )
(public member function of std::basic_ios<CharT,Traits>
) [edit]
returns state flags
(public member function of std::basic_ios<CharT,Traits>
) [edit]
sets state flags
(public member function of std::basic_ios<CharT,Traits>
) [edit]
modifies state flags
(public member function of std::basic_ios<CharT,Traits>
) [edit]
Formatting
copies formatting information
(public member function of std::basic_ios<CharT,Traits>
) [edit]
manages the fill character
(public member function of std::basic_ios<CharT,Traits>
) [edit]
Miscellaneous
manages exception mask
(public member function of std::basic_ios<CharT,Traits>
) [edit]
sets the locale
(public member function of std::basic_ios<CharT,Traits>
) [edit]
manages associated stream buffer
(public member function of std::basic_ios<CharT,Traits>
) [edit]
manages tied stream
(public member function of std::basic_ios<CharT,Traits>
) [edit]
narrows characters
(public member function of std::basic_ios<CharT,Traits>
) [edit]
widens characters
(public member function of std::basic_ios<CharT,Traits>
) [edit]
Member functions
Formatting
manages format flags
(public member function of std::ios_base
) [edit]
sets specific format flag
(public member function of std::ios_base
) [edit]
clears specific format flag
(public member function of std::ios_base
) [edit]
manages decimal precision of floating point operations
(public member function of std::ios_base
) [edit]
manages field width
(public member function of std::ios_base
) [edit]
Locales
sets locale
(public member function of std::ios_base
) [edit]
returns current locale
(public member function of std::ios_base
) [edit]
Internal extensible array
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]
resizes the private storage if necessary and access to the
long element at the given index
(public member function of std::ios_base
) [edit]
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
registers event callback function
(public member function of std::ios_base
) [edit]
sets whether C++ and C I/O libraries are interoperable
(public static member function of std::ios_base
) [edit]
Member classes
stream exception
(public member class of std::ios_base
) [edit]
initializes standard stream objects
(public member class of std::ios_base
) [edit]
Member types and constants
Type
Explanation
stream open mode type
The following constants are also defined:
app
seek to the end of stream before each write
[edit]
trunc
discard the contents of the stream when opening
[edit]
ate
seek to the end of stream immediately after open
[edit]
(typedef) [edit]
formatting flags type
The following constants are also defined:
fixed
generate floating point types using fixed notation, or hex notation if combined with
scientific: see
std::fixed [edit]
showbase
generate a prefix indicating the numeric base for integer output, require the currency indicator in monetary I/O: see
std::showbase [edit]
(typedef) [edit]
state of the stream type
The following constants are also defined:
failbit
input/output operation failed (formatting or extraction error)
[edit]
eofbit
associated input sequence has reached end-of-file
[edit]
(typedef) [edit]
seeking direction type
The following constants are also defined:
cur
the current position of stream position indicator
[edit]
(typedef) [edit]
specifies event type
(enum) [edit]
callback function type
(typedef) [edit]