std::istream (3) - Linux Manuals
std::istream: std::basic_istream
NAME
std::basic_istream - std::basic_istream
Synopsis
Defined in header <istream>
template<
class CharT,
class Traits = std::char_traits<CharT>
> class basic_istream : virtual public std::basic_ios<CharT, Traits>
The class template basic_istream provides support for high level input operations on character streams. The supported operations include formatted input (e.g. integer values or whitespace-separated characters and characters strings) and unformatted input (e.g. raw characters and character arrays). This functionality is implemented in terms of the interface provided by the underlying basic_streambuf class, accessed through the basic_ios base class. The only non-inherited data member of basic_istream, in most implementations, is the value returned by basic_istream::gcount().
std-basic istream-inheritance.svg
Inheritance diagram
Two specializations for common character types are defined:
Defined in header <istream>
Type Definition
istream basic_istream<char>
wistream basic_istream<wchar_t>
Global objects
Two global basic_istream objects are provided by the standard library.
Defined in header <iostream>
cin (global object)
wcin
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
Member functions
constructor (public member function)
destructor destructs the object
[virtual]
operator= move-assigns from another basic_istream
(C++11)
Formatted input
operator>> (public member function)
Unformatted input
get (public member function)
peek (public member function)
unget (public member function)
putback (public member function)
getline (public member function)
ignore (public member function)
read (public member function)
readsome (public member function)
gcount (public member function)
Positioning
tellg (public member function)
seekg (public member function)
Miscellaneous
sync (public member function)
swap swaps stream objects, except for the associated buffer
(C++11)
Member classes
sentry (public member class)
Non-member functions
operator>>(std::basic_istream) (function template)
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 (public member function of std::basic_ios<CharT,Traits>)
eof (public member function of std::basic_ios<CharT,Traits>)
fail (public member function of std::basic_ios<CharT,Traits>)
bad (public member function of std::basic_ios<CharT,Traits>)
operator! (public member function of std::basic_ios<CharT,Traits>)
operator_void*
operator_bool checks if no error has occurred (synonym of !fail())
(until C++11)
(since C++11)
rdstate (public member function of std::basic_ios<CharT,Traits>)
setstate (public member function of std::basic_ios<CharT,Traits>)
clear (public member function of std::basic_ios<CharT,Traits>)
Formatting
copyfmt (public member function of std::basic_ios<CharT,Traits>)
fill (public member function of std::basic_ios<CharT,Traits>)
Miscellaneous
exceptions (public member function of std::basic_ios<CharT,Traits>)
imbue (public member function of std::basic_ios<CharT,Traits>)
rdbuf (public member function of std::basic_ios<CharT,Traits>)
tie (public member function of std::basic_ios<CharT,Traits>)
narrow (public member function of std::basic_ios<CharT,Traits>)
widen (public member function of std::basic_ios<CharT,Traits>)
Inherited from std::ios_base
Member functions
Formatting
flags (public member function of std::ios_base)
setf (public member function of std::ios_base)
unsetf (public member function of std::ios_base)
precision (public member function of std::ios_base)
width (public member function of std::ios_base)
Locales
imbue (public member function of std::ios_base)
getloc (public member function of std::ios_base)
Internal extensible array
xalloc returns a program-wide unique integer that is safe to use as index to pword() and iword()
[static]
iword (public member function of std::ios_base)
pword (public member function of std::ios_base)
Miscellaneous
register_callback (public member function of std::ios_base)
sync_with_stdio sets whether C++ and C IO libraries are interoperable
[static]
Member classes
failure (public member class of std::ios_base)
Init (public member class of std::ios_base)
Member types and constants
Type Explanation
openmode in open for reading
fmtflags fixed generate floating point types using fixed notation, or hex notation if combined with scientific: see std::fixed