Input stream class
iostream library  

Standard hierarchy


Public member functions:

istream members:
(constructor)Construct an object
operator>>Perform formatted input operation (extraction)
gcountGet number of characters extracted by last unformatted input operation
getExtract unformatted data from stream
getlineGet a line from stream
ignoreExtract and discard characters
peekPeek next character
putbackPut the last character back to stream
readRead a block of data
readsomeRead a block of data
seekgSet position of the get pointer
syncSyncronize stream's buffer with source of characters
tellgGet position of the get pointer
ungetMake last character got from stream available again
(destructor)No-op [virtual]
members inherited from ios:
operator void *Convert stream to pointer.
operator !Evaluate stream object.
badCheck if an unrecoverable error has occurred.
clearSet control states.
copyfmtCopy formatting information.
eofCheck if End-Of-File has been reached.
exceptionsGet/set the exception mask.
failCheck if failure has occurred.
fillGet/set the fill character.
goodCheck if stream is good for i/o operations.
imbueImbue locale.
narrowNarrow character.
rdbufGet/set the associated streambuf object.
rdstateGet control state.
setstateSet control state.
tieGet/set the tied stream.
widenWiden character.
members inherited from ios_base:
flagsGet/set format flags.
getlocGet current locale.
imbueImbue locale.
iwordGet reference to a long element of the internal extensible array.
precisionGet/set floating-point decimal presision.
pwordGet reference to a void* element of the internal extensible array.
register_callbackRegister event callback function.
setfSet some format flags.
sync_with_stdioActivates / Deactivates synchronization with cstdio functions. [static]
unsetfClear format flag.
widthGet/set field width.
xallocReturn a new index for the internal extensible array. [static]


istream provides member functions to assist in reading and interpreting input from a stream buffer. These members can be divided into two main groups:
Formatted input
These member functions extract formatted data that may be interpreted from a sequence of characters to any other type. All formatted input is done using the extraction operator (operator>>).
Unformatted input
Most of the other member functions of istream class are used to perform unformatted input, i.e. no interpretation is made on the characters got form input. These functions can get a dertermined number of characters from the input buffer (get, getline, peek, read, readsome), manipulate the get pointer (ignore, seekg, tellg, unget) or get information of last unformatted input operation (gcount).
  The input buffer may be syncronized with the external source of characters by calling member sync.

  Standard object cin is an instatiation of this class.

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