std::basic_iostream
From cppreference.com
C++
Feature test macros (C++20)
Concepts library (C++20)
Metaprogramming library (C++11)
Ranges library (C++20)
Filesystem library (C++17)
Concurrency support library (C++11)
Execution control library (C++26)
Input/output library
Print functions (C++23)
Buffers
(C++23)
(C++98/26*)
(C++20)
Streams
Abstractions
basic_iostream
File I/O
String I/O
Array I/O
(C++23)
(C++23)
(C++23)
(C++98/26*)
(C++98/26*)
(C++98/26*)
Synchronized Output
(C++20)
Types
Error category interface
(C++11)
(C++11)
std::basic_iostream
Member functions
Protected member functions
Defined in header
<istream>
template<
class CharT,
class Traits = std::char_traits <CharT>
> class basic_iostream :
public basic_istream<CharT, Traits>,
The class template basic_iostream provides support for high level input/output operations on streams. The supported operations include sequential reading or writing and formatting. This functionality is implemented over the interface provided by the std::basic_streambuf class. It is accessed through std::basic_ios class.
std-basic iostream-inheritance.svg
Inheritance diagram
Several typedefs for common character types are provided:
Defined in header
<istream> Type
Definition
std::iostream
std::basic_iostream<char>
std::wiostream
std::basic_iostream<wchar_t>
Contents
[edit] Member types
Member type
Definition
[edit] Member functions
[edit] Protected member functions
Inherited from std::basic_istream
Member functions
Formatted input
Unformatted input
reads the next character without extracting it
(public member function of
(public member function of
std::basic_istream<CharT,Traits>) [edit]
puts a character into input stream
(public member function of
(public member function of
std::basic_istream<CharT,Traits>) [edit]
extracts characters until the given character is found
(public member function of
(public member function of
std::basic_istream<CharT,Traits>) [edit]
extracts and discards characters until the given character is found
(public member function of
(public member function of
std::basic_istream<CharT,Traits>) [edit]
extracts already available blocks of characters
(public member function of
(public member function of
std::basic_istream<CharT,Traits>) [edit]
returns number of characters extracted by last unformatted input operation
(public member function of
(public member function of
std::basic_istream<CharT,Traits>) [edit]
Positioning
returns the input position indicator
(public member function of
(public member function of
std::basic_istream<CharT,Traits>) [edit]
sets the input position indicator
(public member function of
(public member function of
std::basic_istream<CharT,Traits>) [edit]
Miscellaneous
synchronizes with the underlying storage device
(public member function of
(public member function of
std::basic_istream<CharT,Traits>) [edit]
Member classes
Inherited from std::basic_ostream
Member functions
Formatted output
Unformatted output
Positioning
returns the output position indicator
(public member function of
(public member function of
std::basic_ostream<CharT,Traits>) [edit]
sets the output position indicator
(public member function of
(public member function of
std::basic_ostream<CharT,Traits>) [edit]
Miscellaneous
synchronizes with the underlying storage device
(public member function of
(public member function of
std::basic_ostream<CharT,Traits>) [edit]
Member classes
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
checks if no error has occurred i.e. I/O operations are available
(public member function of
(public member function of
std::basic_ios<CharT,Traits>) [edit]
checks if end-of-file has been reached
(public member function of
(public member function of
std::basic_ios<CharT,Traits>) [edit]
checks if a non-recoverable error has occurred
(public member function of
(public member function of
std::basic_ios<CharT,Traits>) [edit]
checks if an error has occurred (synonym of fail() )
(public member function of
(public member function of
std::basic_ios<CharT,Traits>) [edit]
checks if no error has occurred (synonym of
(public member function of
!fail() ) (public member function of
std::basic_ios<CharT,Traits>) [edit]
Formatting
Miscellaneous
Inherited from std::ios_base
Member functions
Formatting
manages decimal precision of floating point operations
(public member function of
(public member function of
std::ios_base) [edit]
Locales
Internal extensible array
[static]
(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
(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
(public member function of
std::ios_base) [edit]
Miscellaneous
[static]
(public static member function of
std::ios_base) [edit]
Member classes
Member types and constants
Type
Explanation
stream open mode type
(typedef) [edit]
formatting flags type
(typedef) [edit]
state of the stream type
(typedef) [edit]
seeking direction type
(typedef) [edit]
specifies event type
(enum) [edit]
callback function type
(typedef) [edit]
The following constants are also defined:
Constant
Explanation[edit]
(typedef) [edit]
The following constants are also defined:
Constant
Explanation[edit]
internal
internal adjustment (adds fill characters to the internal designated point): see std::internal [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]
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]
uppercase
replace certain lowercase letters with their uppercase equivalents in certain output operations: see std::uppercase [edit]
(typedef) [edit]
The following constants are also defined:
Constant
Explanation[edit]
(typedef) [edit]
The following constants are also defined:
Constant
Explanation[edit]
(typedef) [edit]
(enum) [edit]
(typedef) [edit]
[edit] 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 271 | C++98 | the member types char_type, traits_type, int_type, pos_type and off_type were not defined(std::basic_istream and std::basic_ostream both define these types, resulted in ambiguity) |
define these types |