Set control state.
  Modifies the current control state value by adding (bitwise OR) the error state flags passed as paremeter to the current state.
  Any error bit already set is not cleared. If you want to modify the state flags without keeping the current value use clear instead.
  The effect of this function is as to call:
    clear ( rdstate() | state );

Parameters.

state

  An object of type ios_base::iostate that can take as value any combination of the following state flag member constants:

• badbit  (critical error in stream buffer)
• eofbit  (End-Of-File reached while extracting)
• failbit (failure extracting from stream)

  These are static member constants inherited from ios_base. You may combine more than one state flag bitmask using the bitwise | (or) operator.

Return Value.
  none

Basic template member declaration ( basic_ios<charT,traits> ):

void setstate ( iostate state );

See also.
  fail, good, bad, eof, rdstate, clear
  ios class