std::basic_istream
| Defined in header <istream>
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| template< class CharT, |
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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().
Two specializations for common character types are defined:
| Defined in header
<istream> | |
| Type | Definition |
istream
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basic_istream<char> |
wistream
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basic_istream<wchar_t> |
Contents |
[edit] Global objects
Two global basic_istream objects are provided by the standard library.
| Defined in header
<iostream> | |
| reads from the standard C input stream stdin (global object) | |
[edit] Member types
| Member type | Definition |
char_type
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CharT |
traits_type
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Traits |
int_type
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Traits::int_type |
pos_type
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Traits::pos_type |
off_type
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Traits::off_type |
[edit] Member functions
| constructs the object (public member function) | |
| [virtual] |
destructs the object (virtual public member function) |
| (C++11) |
replaces the buffer object (protected member function) |
Formatted input | |
| extracts formatted data (public member function) | |
Unformatted input | |
| extracts characters (public member function) | |
| reads the next character without extracting it (public member function) | |
| unextracts a character (public member function) | |
| puts character into input stream (public member function) | |
| extracts characters until the given character is found (public member function) | |
| extracts and discards characters until the given character is found (public member function) | |
| extracts blocks of characters (public member function) | |
| extracts already available blocks of characters (public member function) | |
| returns number of characters extracted by last unformatted input operation (public member function) | |
Positioning | |
| returns the input position indicator (public member function) | |
| sets the input position indicator (public member function) | |
Miscellaneous | |
| synchronizes with the underlying storage device (public member function) | |
| (C++11) |
swaps stream objects, except for the associated buffer (protected member function) |
[edit] Member classes
| implements basic logic for preparation of the stream for input operations (public member class) |
[edit] Non-member functions
| extracts characters and character arrays (function template) |
Inherited from std::basic_ios
Member types
| Member type | Definition |
char_type
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CharT |
traits_type
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Traits |
int_type
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Traits::int_type |
pos_type
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Traits::pos_type |
off_type
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Traits::off_type |
State functions | |
| checks if no error has occurred i.e. I/O operations are available (public member function of std::basic_ios)
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| checks if end-of-file has been reached (public member function of std::basic_ios)
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| checks if a recoverable error has occurred (public member function of std::basic_ios)
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| checks if a non-recoverable error has occurred (public member function of std::basic_ios)
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| checks if an error has occurred (synonym of fail()) (public member function of std::basic_ios)
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| (until C++11)(since C++11) |
checks if no error has occurred (synonym of !fail()) (public member function of std::basic_ios)
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| returns state flags (public member function of std::basic_ios)
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| sets state flags (public member function of std::basic_ios)
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| clears error and eof flags (public member function of std::basic_ios)
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Formatting | |
| copies formatting information (public member function of std::basic_ios)
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| manages the fill character (public member function of std::basic_ios)
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Miscellaneous | |
| manages exception mask (public member function of std::basic_ios)
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| sets the locale (public member function of std::basic_ios)
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| manages associated stream buffer (public member function of std::basic_ios)
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| manages tied stream (public member function of std::basic_ios)
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| narrows characters (public member function of std::basic_ios)
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| widens characters (public member function of std::basic_ios)
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Inherited from std::ios_base
Member functions
Formatting | |
| manages format flags (public member function of std::ios_base)
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| sets specific format flag (public member function of std::ios_base)
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| clears specific format flag (public member function of std::ios_base)
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| manages decimal precision of floating point operations (public member function of std::ios_base)
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| manages field width (public member function of std::ios_base)
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Locales | |
| sets locale (public member function of std::ios_base)
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| returns current locale (public member function of std::ios_base)
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Internal extensible array | |
| [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)
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| resizes the private storage if necessary and access to the long element at the given index (public member function of std::ios_base)
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| resizes the private storage if necessary and access to the void* element at the given index (public member function of std::ios_base)
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Miscellaneous | |
| registers event callback function (public member function of std::ios_base)
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| [static] |
sets whether C++ and C IO libraries are interoperable (public static member function of std::ios_base)
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Member classes | |
| stream exception (public member class of std::ios_base)
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| initializes standard stream objects (public member class of std::ios_base)
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Member types and constants | |||||||||||||||||||||||||||||||||||||||
| Type | Explanation | ||||||||||||||||||||||||||||||||||||||
| stream open mode type
The following constants are also defined:
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| formatting flags type
The following constants are also defined:
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| state of the stream type
The following constants are also defined:
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| seeking direction type
The following constants are also defined:
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| specifies event type (enum) | |||||||||||||||||||||||||||||||||||||||
| callback function type (typedef) | |||||||||||||||||||||||||||||||||||||||
