IRIX Base Documentation 2001 May/SGI IRIX Base Documentation 2001 May.iso/usr/share/catman/p_man/cat3/c++/ios.z/ios

Text File | 1998-10-30 | 50.9 KB | 661 lines

IIIIOOOOSSSS((((3333CCCC++++++++))))                                                            IIIIOOOOSSSS((((3333CCCC++++++++))))



NNNNAAAAMMMMEEEE
     ios - input/output formatting

SSSSYYYYNNNNOOOOPPPPSSSSIIIISSSS
     _####_iiii_nnnn_cccc_llll_uuuu_dddd_eeee _<<<<_iiii_oooo_ssss_tttt_rrrr_eeee_aaaa_mmmm_...._hhhh_>>>>

     _cccc_llll_aaaa_ssss_ssss _iiii_oooo_ssss _{{{{
     _pppp_uuuu_bbbb_llll_iiii_cccc_::::
               _eeee_nnnn_uuuu_mmmm      _iiii_oooo______ssss_tttt_aaaa_tttt_eeee _{{{{ _gggg_oooo_oooo_dddd_bbbb_iiii_tttt_====_0000_,,,, _eeee_oooo_ffff_bbbb_iiii_tttt_,,,, _ffff_aaaa_iiii_llll_bbbb_iiii_tttt_,,,, _bbbb_aaaa_dddd_bbbb_iiii_tttt _}}}}_;;;;
               _eeee_nnnn_uuuu_mmmm      _oooo_pppp_eeee_nnnn______mmmm_oooo_dddd_eeee _{{{{ _iiii_nnnn_,,,, _oooo_uuuu_tttt_,,,, _aaaa_tttt_eeee_,,,, _aaaa_pppp_pppp_,,,, _tttt_rrrr_uuuu_nnnn_cccc_,,,, _nnnn_oooo_cccc_rrrr_eeee_aaaa_tttt_eeee_,,,, _nnnn_oooo_rrrr_eeee_pppp_llll_aaaa_cccc_eeee _}}}}_;;;;
               _eeee_nnnn_uuuu_mmmm      _ssss_eeee_eeee_kkkk______dddd_iiii_rrrr _{{{{ _bbbb_eeee_gggg_,,,, _cccc_uuuu_rrrr_,,,, _eeee_nnnn_dddd _}}}}_;;;;
               _////_**** _ffff_llll_aaaa_gggg_ssss _ffff_oooo_rrrr _cccc_oooo_nnnn_tttt_rrrr_oooo_llll_llll_iiii_nnnn_gggg _ffff_oooo_rrrr_mmmm_aaaa_tttt _****_////
               _eeee_nnnn_uuuu_mmmm      _{{{{ _ssss_kkkk_iiii_pppp_wwww_ssss_====_0000_1111_,,,,
                           _llll_eeee_ffff_tttt_====_0000_2222_,,,,  _rrrr_iiii_gggg_hhhh_tttt_====_0000_4444_,,,, _iiii_nnnn_tttt_eeee_rrrr_nnnn_aaaa_llll_====_0000_1111_0000_,,,,
                           _dddd_eeee_cccc_====_0000_2222_0000_,,,, _oooo_cccc_tttt_====_0000_4444_0000_,,,, _hhhh_eeee_xxxx_====_0000_1111_0000_0000_,,,,
                           _ssss_hhhh_oooo_wwww_bbbb_aaaa_ssss_eeee_====_0000_2222_0000_0000_,,,, _ssss_hhhh_oooo_wwww_pppp_oooo_iiii_nnnn_tttt_====_0000_4444_0000_0000_,,,, _uuuu_pppp_pppp_eeee_rrrr_cccc_aaaa_ssss_eeee_====_0000_1111_0000_0000_0000_,,,, _ssss_hhhh_oooo_wwww_pppp_oooo_ssss_====_0000_2222_0000_0000_0000_,,,,
                           _ssss_cccc_iiii_eeee_nnnn_tttt_iiii_ffff_iiii_cccc_====_0000_4444_0000_0000_0000_,,,, _ffff_iiii_xxxx_eeee_dddd_====_0000_1111_0000_0000_0000_0000_,,,,
                           _uuuu_nnnn_iiii_tttt_bbbb_uuuu_ffff_====_0000_2222_0000_0000_0000_0000_,,,, _ssss_tttt_dddd_iiii_oooo_====_0000_4444_0000_0000_0000_0000 _}}}}_;;;;
               _ssss_tttt_aaaa_tttt_iiii_cccc _cccc_oooo_nnnn_ssss_tttt _llll_oooo_nnnn_gggg _bbbb_aaaa_ssss_eeee_ffff_iiii_eeee_llll_dddd_;;;;
                         _////_**** _dddd_eeee_cccc_||||_oooo_cccc_tttt_||||_hhhh_eeee_xxxx _****_////
               _ssss_tttt_aaaa_tttt_iiii_cccc _cccc_oooo_nnnn_ssss_tttt _llll_oooo_nnnn_gggg _aaaa_dddd_jjjj_uuuu_ssss_tttt_ffff_iiii_eeee_llll_dddd_;;;;
                         _////_**** _llll_eeee_ffff_tttt_||||_rrrr_iiii_gggg_hhhh_tttt_||||_iiii_nnnn_tttt_eeee_rrrr_nnnn_aaaa_llll _****_////
               _ssss_tttt_aaaa_tttt_iiii_cccc _cccc_oooo_nnnn_ssss_tttt _llll_oooo_nnnn_gggg _ffff_llll_oooo_aaaa_tttt_ffff_iiii_eeee_llll_dddd_;;;;
                         _////_**** _ssss_cccc_iiii_eeee_nnnn_tttt_iiii_ffff_iiii_cccc_||||_ffff_iiii_xxxx_eeee_dddd _****_////
     _pppp_uuuu_bbbb_llll_iiii_cccc_::::
                         _iiii_oooo_ssss_((((_ssss_tttt_rrrr_eeee_aaaa_mmmm_bbbb_uuuu_ffff_****_))))_;;;;

               _iiii_nnnn_tttt       _bbbb_aaaa_dddd_((((_))))_;;;;
               _ssss_tttt_aaaa_tttt_iiii_cccc _llll_oooo_nnnn_gggg_bbbb_iiii_tttt_aaaa_llll_llll_oooo_cccc_((((_))))_;;;;
               _vvvv_oooo_iiii_dddd      _cccc_llll_eeee_aaaa_rrrr_((((_iiii_nnnn_tttt _ssss_tttt_aaaa_tttt_eeee _====_0000_))))_;;;;
               _iiii_nnnn_tttt       _eeee_oooo_ffff_((((_))))_;;;;
               _iiii_nnnn_tttt       _ffff_aaaa_iiii_llll_((((_))))_;;;;
               _cccc_hhhh_aaaa_rrrr      _ffff_iiii_llll_llll_((((_))))_;;;;
               _cccc_hhhh_aaaa_rrrr      _ffff_iiii_llll_llll_((((_cccc_hhhh_aaaa_rrrr_))))_;;;;
               _llll_oooo_nnnn_gggg      _ffff_llll_aaaa_gggg_ssss_((((_))))_;;;;
               _llll_oooo_nnnn_gggg      _ffff_llll_aaaa_gggg_ssss_((((_llll_oooo_nnnn_gggg_))))_;;;;
               _iiii_nnnn_tttt       _gggg_oooo_oooo_dddd_((((_))))_;;;;
               _llll_oooo_nnnn_gggg_&&&&     _iiii_wwww_oooo_rrrr_dddd_((((_iiii_nnnn_tttt_))))_;;;;
               _iiii_nnnn_tttt       _oooo_pppp_eeee_rrrr_aaaa_tttt_oooo_rrrr_!!!!_((((_))))_;;;;
                         _oooo_pppp_eeee_rrrr_aaaa_tttt_oooo_rrrr _vvvv_oooo_iiii_dddd_****_((((_))))_;;;;
               _iiii_nnnn_tttt       _pppp_rrrr_eeee_cccc_iiii_ssss_iiii_oooo_nnnn_((((_))))_;;;;
               _iiii_nnnn_tttt       _pppp_rrrr_eeee_cccc_iiii_ssss_iiii_oooo_nnnn_((((_iiii_nnnn_tttt_))))_;;;;
               _ssss_tttt_rrrr_eeee_aaaa_mmmm_bbbb_uuuu_ffff_****_rrrr_dddd_bbbb_uuuu_ffff_((((_))))_;;;;
               _vvvv_oooo_iiii_dddd_**** _&&&&   _pppp_wwww_oooo_rrrr_dddd_((((_iiii_nnnn_tttt_))))_;;;;
               _iiii_nnnn_tttt       _rrrr_dddd_ssss_tttt_aaaa_tttt_eeee_((((_))))_;;;;
               _llll_oooo_nnnn_gggg      _ssss_eeee_tttt_ffff_((((_llll_oooo_nnnn_gggg _ssss_eeee_tttt_bbbb_iiii_tttt_ssss_,,,, _llll_oooo_nnnn_gggg _ffff_iiii_eeee_llll_dddd_))))_;;;;
               _llll_oooo_nnnn_gggg      _ssss_eeee_tttt_ffff_((((_llll_oooo_nnnn_gggg_))))_;;;;
               _ssss_tttt_aaaa_tttt_iiii_cccc _vvvv_oooo_iiii_dddd_ssss_yyyy_nnnn_cccc______wwww_iiii_tttt_hhhh______ssss_tttt_dddd_iiii_oooo_((((_))))_;;;;
               _oooo_ssss_tttt_rrrr_eeee_aaaa_mmmm_****  _tttt_iiii_eeee_((((_))))_;;;;
               _oooo_ssss_tttt_rrrr_eeee_aaaa_mmmm_****  _tttt_iiii_eeee_((((_oooo_ssss_tttt_rrrr_eeee_aaaa_mmmm_****_))))_;;;;
               _llll_oooo_nnnn_gggg      _uuuu_nnnn_ssss_eeee_tttt_ffff_((((_llll_oooo_nnnn_gggg_))))_;;;;
               _iiii_nnnn_tttt       _wwww_iiii_dddd_tttt_hhhh_((((_))))_;;;;



                                                                        PPPPaaaaggggeeee 1111






IIIIOOOOSSSS((((3333CCCC++++++++))))                                                            IIIIOOOOSSSS((((3333CCCC++++++++))))



              _iiii_nnnn_tttt        _wwww_iiii_dddd_tttt_hhhh_((((_iiii_nnnn_tttt_))))_;;;;
               _ssss_tttt_aaaa_tttt_iiii_cccc _iiii_nnnn_tttt_xxxx_aaaa_llll_llll_oooo_cccc_((((_))))_;;;;
     _pppp_rrrr_oooo_tttt_eeee_cccc_tttt_eeee_dddd_::::
                         _iiii_oooo_ssss_((((_))))_;;;;
                         _iiii_nnnn_iiii_tttt_((((_ssss_tttt_rrrr_eeee_aaaa_mmmm_bbbb_uuuu_ffff_****_))))_;;;;
     _pppp_rrrr_iiii_vvvv_aaaa_tttt_eeee_::::
                         _iiii_oooo_ssss_((((_iiii_oooo_ssss_&&&&_))))_;;;;
               _vvvv_oooo_iiii_dddd      _oooo_pppp_eeee_rrrr_aaaa_tttt_oooo_rrrr_====_((((_iiii_oooo_ssss_&&&&_))))_;;;;
     _}}}}_;;;;

               _////_**** _MMMM_aaaa_nnnn_iiii_pppp_uuuu_llll_aaaa_tttt_oooo_rrrr_ssss _****_////
     _iiii_oooo_ssss_&&&&      _dddd_eeee_cccc_((((_iiii_oooo_ssss_&&&&_)))) _;;;;
     _iiii_oooo_ssss_&&&&      _hhhh_eeee_xxxx_((((_iiii_oooo_ssss_&&&&_)))) _;;;;
     _iiii_oooo_ssss_&&&&      _oooo_cccc_tttt_((((_iiii_oooo_ssss_&&&&_)))) _;;;;
     _oooo_ssss_tttt_rrrr_eeee_aaaa_mmmm_&&&&  _eeee_nnnn_dddd_llll_((((_oooo_ssss_tttt_rrrr_eeee_aaaa_mmmm_&&&& _iiii_)))) _;;;;
     _oooo_ssss_tttt_rrrr_eeee_aaaa_mmmm_&&&&  _eeee_nnnn_dddd_ssss_((((_oooo_ssss_tttt_rrrr_eeee_aaaa_mmmm_&&&& _iiii_)))) _;;;;
     _oooo_ssss_tttt_rrrr_eeee_aaaa_mmmm_&&&&  _ffff_llll_uuuu_ssss_hhhh_((((_oooo_ssss_tttt_rrrr_eeee_aaaa_mmmm_&&&&_)))) _;;;;
     _iiii_ssss_tttt_rrrr_eeee_aaaa_mmmm_&&&&  _wwww_ssss_((((_iiii_ssss_tttt_rrrr_eeee_aaaa_mmmm_&&&&_)))) _;;;;

DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNN
     The stream classes derived from class _iiii_oooo_ssss provide a high level interface
     that supports transferring formatted and unformatted information into and
     out of _ssss_tttt_rrrr_eeee_aaaa_mmmm_bbbb_uuuu_ffffs.  This manual page describes the operations common to
     both input and output.

     Several enumerations are declared in class _iiii_oooo_ssss, _oooo_pppp_eeee_nnnn______mmmm_oooo_dddd_eeee, _iiii_oooo______ssss_tttt_aaaa_tttt_eeee,
     _ssss_eeee_eeee_kkkk______dddd_iiii_rrrr, and format flags, to avoid polluting the global name space.
     The _iiii_oooo______ssss_tttt_aaaa_tttt_eeees are described on this manual page under ``Error States.''
     The format fields are also described on this page, under ``Formatting.''
     The _oooo_pppp_eeee_nnnn______mmmm_oooo_dddd_eeees are described in detail in _ffff_ssss_tttt_rrrr_eeee_aaaa_mmmm(3C++) under _oooo_pppp_eeee_nnnn_((((_)))).
     The _ssss_eeee_eeee_kkkk______dddd_iiii_rrrrs are described in _ssss_bbbb_uuuu_ffff_...._pppp_uuuu_bbbb(3C++) under _ssss_eeee_eeee_kkkk_oooo_ffff_ffff_((((_)))).

     In the following descriptions assume:
          - _s and _s_2 are _iiii_oooo_sssss.
          - _s_r is an _iiii_oooo_ssss_&&&&.
          - _s_p is a _iiii_oooo_ssss_****.
          - _i, _o_i, _j, and _n are _iiii_nnnn_tttts.
          - _l, _f, and _b are _llll_oooo_nnnn_ggggs.
          - _c and _o_c are _cccc_hhhh_aaaa_rrrrs.
          - _o_s_p and _o_o_s_p are _oooo_ssss_tttt_rrrr_eeee_aaaa_mmmm_****s.
          - _s_b is a _ssss_tttt_rrrr_eeee_aaaa_mmmm_bbbb_uuuu_ffff_****.
          - _p_o_s is a _ssss_tttt_rrrr_eeee_aaaa_mmmm_pppp_oooo_ssss.
          - _o_f_f is a _ssss_tttt_rrrr_eeee_aaaa_mmmm_oooo_ffff_ffff.
          - _d_i_r is a _ssss_eeee_eeee_kkkk______dddd_iiii_rrrr.
          - _m_o_d_e is an _iiii_nnnn_tttt representing an _oooo_pppp_eeee_nnnn______mmmm_oooo_dddd_eeee.
          - _f_c_t is a function with type _iiii_oooo_ssss_&&&& _((((_****_))))_((((_iiii_oooo_ssss_&&&&_)))).
          - _v_p is a _vvvv_oooo_iiii_dddd_****_&&&&.

   CCCCoooonnnnssssttttrrrruuuuccccttttoooorrrrssss aaaannnndddd aaaassssssssiiiiggggnnnnmmmmeeeennnntttt::::
          _iiii_oooo_ssss_((((_s_b_))))
               The _ssss_tttt_rrrr_eeee_aaaa_mmmm_bbbb_uuuu_ffff denoted by _s_b becomes the _ssss_tttt_rrrr_eeee_aaaa_mmmm_bbbb_uuuu_ffff associated
               with the constructed _iiii_oooo_ssss.  If _s_b is null, the effect is



                                                                        PPPPaaaaggggeeee 2222






IIIIOOOOSSSS((((3333CCCC++++++++))))                                                            IIIIOOOOSSSS((((3333CCCC++++++++))))



               undefined.

          _iiii_oooo_ssss_((((_s_r_))))
          _s_2_====_s
               Copying of _iiii_oooo_sssss is not well-defined in general, therefore the
               constructor and assignment operators are private so that the
               compiler will complain about attempts to copy _iiii_oooo_ssss objects.
               Copying pointers to _iiii_oooo_ssss_tttt_rrrr_eeee_aaaa_mmmms is usually what is desired.

          _iiii_oooo_ssss_((((_))))
          _iiii_nnnn_iiii_tttt_((((_s_b_))))
               Because class _iiii_oooo_ssss is now inherited as a virtual base class, a
               constructor with no arguments must be used.  This constructor
               is declared protected.  Therefore _iiii_oooo_ssss_::::_::::_iiii_nnnn_iiii_tttt_((((_ssss_tttt_rrrr_eeee_aaaa_mmmm_bbbb_uuuu_ffff_****_)))) is
               declared protected and must be used for initialization of
               derived classes.

   EEEErrrrrrrroooorrrr SSSSttttaaaatttteeeessss
     An _iiii_oooo_ssss has an internal _e_r_r_o_r _s_t_a_t_e (which is a collection of the bits
     declared as _iiii_oooo______ssss_tttt_aaaa_tttt_eeees).  Members related to the error state are:

          _i_====_s_...._rrrr_dddd_ssss_tttt_aaaa_tttt_eeee_((((_))))
               Returns the current error state.

          _s_...._cccc_llll_eeee_aaaa_rrrr_((((_i_))))
               Stores _i as the error state.  If _i is zero, this clears all
               bits.  To set a bit without clearing previously set bits
               requires something like _s_...._cccc_llll_eeee_aaaa_rrrr_((((_iiii_oooo_ssss_::::_::::_bbbb_aaaa_dddd_bbbb_iiii_tttt_||||_ssss_...._rrrr_dddd_ssss_tttt_aaaa_tttt_eeee_((((_))))_)))).

          _i_====_s_...._gggg_oooo_oooo_dddd_((((_))))
               Returns non-zero if the error state has no bits set, zero
               otherwise.

          _i_====_s_...._eeee_oooo_ffff_((((_))))
               Returns non-zero if _eeee_oooo_ffff_bbbb_iiii_tttt is set in the error state, zero
               otherwise.  Normally this bit is set when an end-of-file has
               been encountered during an extraction.

          _i_====_s_...._ffff_aaaa_iiii_llll_((((_))))
               Returns non-zero if either _bbbb_aaaa_dddd_bbbb_iiii_tttt or _ffff_aaaa_iiii_llll_bbbb_iiii_tttt is set in the
               error state, zero otherwise.  Normally this indicates that some
               extraction or conversion has failed, but the stream is still
               usable.  That is, once the _ffff_aaaa_iiii_llll_bbbb_iiii_tttt is cleared, I/O on _s can
               usually continue.

          _i_====_s_...._bbbb_aaaa_dddd_((((_))))
               Returns non-zero if _bbbb_aaaa_dddd_bbbb_iiii_tttt is set in the error state, zero
               otherwise.  This usually indicates that some operation on
               _s_...._rrrr_dddd_bbbb_uuuu_ffff_((((_)))) has failed, a severe error, from which recovery is
               probably impossible.  That is, it will probably be impossible
               to continue I/O operations on _s.




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IIIIOOOOSSSS((((3333CCCC++++++++))))                                                            IIIIOOOOSSSS((((3333CCCC++++++++))))



   OOOOppppeeeerrrraaaattttoooorrrrssss
     Two operators are defined to allow convenient checking of the error state
     of an _iiii_oooo_ssss:  _oooo_pppp_eeee_rrrr_aaaa_tttt_oooo_rrrr_!!!!_((((_)))) and _oooo_pppp_eeee_rrrr_aaaa_tttt_oooo_rrrr _vvvv_oooo_iiii_dddd_****_((((_)))).  The latter converts an _iiii_oooo_ssss
     to a pointer so that it can be compared to zero.  The conversion will
     return 0 if _ffff_aaaa_iiii_llll_bbbb_iiii_tttt or _bbbb_aaaa_dddd_bbbb_iiii_tttt is set in the error state, and will return
     a pointer value otherwise.  This pointer is not meant to be used.  This
     allows one to write expressions such as:

          _iiii_ffff _(((( _cccc_iiii_nnnn _)))) _...._...._....

          _iiii_ffff _(((( _cccc_iiii_nnnn _>>>>_>>>> _xxxx _)))) _...._...._....


     The _!!!! operator returns non-zero if _ffff_aaaa_iiii_llll_bbbb_iiii_tttt or _bbbb_aaaa_dddd_bbbb_iiii_tttt is set in the error
     state, which allows expressions like the following to be used:

          _iiii_ffff _(((( _!!!!_cccc_oooo_uuuu_tttt _)))) _...._...._....


   FFFFoooorrrrmmmmaaaattttttttiiiinnnngggg
     An _iiii_oooo_ssss has a _f_o_r_m_a_t _s_t_a_t_e that is used by input and output operations to
     control the details of formatting operations.  For other operations the
     format state has no particular effect and its components may be set and
     examined arbitrarily by user code.  Most formatting details are
     controlled by using the _ffff_llll_aaaa_gggg_ssss_((((_)))), _ssss_eeee_tttt_ffff_((((_)))), and _uuuu_nnnn_ssss_eeee_tttt_ffff_((((_)))) functions to set
     the following flags, which are declared in an enumeration in class _iiii_oooo_ssss.
     Three other components of the format state are controlled separately with
     the functions _ffff_iiii_llll_llll_((((_)))), _wwww_iiii_dddd_tttt_hhhh_((((_)))), and _pppp_rrrr_eeee_cccc_iiii_ssss_iiii_oooo_nnnn_((((_)))).

          _ssss_kkkk_iiii_pppp_wwww_ssss
               If _ssss_kkkk_iiii_pppp_wwww_ssss is set, whitespace will be skipped on input.  This
               applies to scalar extractions.  When _ssss_kkkk_iiii_pppp_wwww_ssss is not set,
               whitespace is not skipped before the extractor begins
               conversion.  If _ssss_kkkk_iiii_pppp_wwww_ssss is not set and a zero length field is
               encountered, the extractor will signal an error.  Additionally,
               the arithmetic extractors will signal an error if _ssss_kkkk_iiii_pppp_wwww_ssss is not
               set and a whitespace is encountered.

          _llll_eeee_ffff_tttt
          _rrrr_iiii_gggg_hhhh_tttt
          _iiii_nnnn_tttt_eeee_rrrr_nnnn_aaaa_llll
               These flags control the padding of a value.  When _llll_eeee_ffff_tttt is set,
               the value is left-adjusted, that is, the fill character is
               added after the value.  When _rrrr_iiii_gggg_hhhh_tttt is set, the value is right-
               adjusted, that is, the fill character is added before the
               value.  When _iiii_nnnn_tttt_eeee_rrrr_nnnn_aaaa_llll is set, the fill character is added after
               any leading sign or base indication, but before the value.
               Right-adjustment is the default if none of these flags is set.
               These fields are collectively identified by the static member,
               _iiii_oooo_ssss_::::_::::_aaaa_dddd_jjjj_uuuu_ssss_tttt_ffff_iiii_eeee_llll_dddd.  The fill character is controlled by the
               _ffff_iiii_llll_llll_((((_)))) function, and the width of padding is controlled by the
               _wwww_iiii_dddd_tttt_hhhh_((((_)))) function.



                                                                        PPPPaaaaggggeeee 4444






IIIIOOOOSSSS((((3333CCCC++++++++))))                                                            IIIIOOOOSSSS((((3333CCCC++++++++))))



          _dddd_eeee_cccc
          _oooo_cccc_tttt
          _hhhh_eeee_xxxx
               These flags control the conversion base of a value.  The
               conversion base is 10 (decimal) if _dddd_eeee_cccc is set, but if _oooo_cccc_tttt or
               _hhhh_eeee_xxxx is set, conversions are done in octal or hexadecimal,
               respectively.  If none of these is set, insertions are in
               decimal, but extractions are interpreted according to the C++
               lexical conventions for integral constants.  These fields are
               collectively identified by the static member, _iiii_oooo_ssss_::::_::::_bbbb_aaaa_ssss_eeee_ffff_iiii_eeee_llll_dddd.
               The manipulators _hhhh_eeee_xxxx, _dddd_eeee_cccc, and _oooo_cccc_tttt can also be used to set the
               conversion base; see ``Built-in Manipulators'' below.

          _ssss_hhhh_oooo_wwww_bbbb_aaaa_ssss_eeee
               If _ssss_hhhh_oooo_wwww_bbbb_aaaa_ssss_eeee is set, insertions will be converted to an external
               form that can be read according to the C++ lexical conventions
               for integral constants.  _ssss_hhhh_oooo_wwww_bbbb_aaaa_ssss_eeee is unset by default.

          _ssss_hhhh_oooo_wwww_pppp_oooo_ssss
               If _ssss_hhhh_oooo_wwww_pppp_oooo_ssss is set, then a ``+'' will be inserted into a decimal
               conversion of a positive integral value.

          _uuuu_pppp_pppp_eeee_rrrr_cccc_aaaa_ssss_eeee
               If _uuuu_pppp_pppp_eeee_rrrr_cccc_aaaa_ssss_eeee is set, then an uppercase ``X`` will be used for
               hexadecimal conversion when _ssss_hhhh_oooo_wwww_bbbb_aaaa_ssss_eeee is set, or an uppercase
               ``E'' will be used to print floating point numbers in
               scientific notation.

          _ssss_hhhh_oooo_wwww_pppp_oooo_iiii_nnnn_tttt
               If _ssss_hhhh_oooo_wwww_pppp_oooo_iiii_nnnn_tttt is set, trailing zeros and decimal points appear
               in the result of a floating point conversion.

          _ssss_cccc_iiii_eeee_nnnn_tttt_iiii_ffff_iiii_cccc
          _ffff_iiii_xxxx_eeee_dddd
               These flags control the format to which a floating point value
               is converted for insertion into a stream.  If _ssss_cccc_iiii_eeee_nnnn_tttt_iiii_ffff_iiii_cccc is
               set, the value is converted using scientific notation, where
               there is one digit before the decimal point and the number of
               digits after it is equal to the _pppp_rrrr_eeee_cccc_iiii_ssss_iiii_oooo_nnnn (see below), which is
               six by default.  An uppercase ``E'' will introduce the exponent
               if _uuuu_pppp_pppp_eeee_rrrr_cccc_aaaa_ssss_eeee is set, a lowercase ``e'' will appear otherwise.
               If _ffff_iiii_xxxx_eeee_dddd is set, the value is converted to decimal notation
               with _pppp_rrrr_eeee_cccc_iiii_ssss_iiii_oooo_nnnn digits after the decimal point, or six by
               default.  If neither _ssss_cccc_iiii_eeee_nnnn_tttt_iiii_ffff_iiii_cccc nor _ffff_iiii_xxxx_eeee_dddd is set, then the
               value will be converted using either notation, depending on the
               value;  scientific notation will be used if the exponent
               resulting from the conversion is less than -4 or greater than
               or equal to precision digits.  Otherwise the value will be
               converted to decimal notation with _pppp_rrrr_eeee_cccc_iiii_ssss_iiii_oooo_nnnn digits total.  If
               _ssss_hhhh_oooo_wwww_pppp_oooo_iiii_nnnn_tttt is not set, trailing zeroes are removed from the
               result and a decimal point appears only if it is followed by a
               digit.  _ssss_cccc_iiii_eeee_nnnn_tttt_iiii_ffff_iiii_cccc and _ffff_iiii_xxxx_eeee_dddd are collectively identified by the



                                                                        PPPPaaaaggggeeee 5555






IIIIOOOOSSSS((((3333CCCC++++++++))))                                                            IIIIOOOOSSSS((((3333CCCC++++++++))))



               static member _iiii_oooo_ssss_::::_::::_ffff_llll_oooo_aaaa_tttt_ffff_iiii_eeee_llll_dddd.

          _uuuu_nnnn_iiii_tttt_bbbb_uuuu_ffff
               When set, a flush is performed by _oooo_ssss_tttt_rrrr_eeee_aaaa_mmmm_::::_::::_oooo_ssss_ffff_xxxx_((((_)))) after each
               insertion.  Unit buffering provides a compromise between
               buffered output and unbuffered output.  Performance is better
               under unit buffering than unbuffered output, which makes a
               system call for each character output.  Unit buffering makes a
               system call for each insertion operation, and doesn't require
               the user to call _oooo_ssss_tttt_rrrr_eeee_aaaa_mmmm_::::_::::_ffff_llll_uuuu_ssss_hhhh_((((_)))).

          _ssss_tttt_dddd_iiii_oooo
               When set, _ssss_tttt_dddd_oooo_uuuu_tttt and _ssss_tttt_dddd_eeee_rrrr_rrrr are flushed by _oooo_ssss_tttt_rrrr_eeee_aaaa_mmmm_::::_::::_oooo_ssss_ffff_xxxx_((((_))))
               after each insertion.

     The following functions use and set the format flags and variables.

          _o_c_====_s_...._ffff_iiii_llll_llll_((((_c_))))
               Sets the ``fill character'' format state variable to _c and
               returns the previous value.  _c will be used as the padding
               character, if one is necessary (see _wwww_iiii_dddd_tttt_hhhh(), below).  The
               default fill or padding character is a space.  The positioning
               of the fill character is determined by the _rrrr_iiii_gggg_hhhh_tttt, _llll_eeee_ffff_tttt, and
               _iiii_nnnn_tttt_eeee_rrrr_nnnn_aaaa_llll flags; see above.  A parameterized manipulator,
               _ssss_eeee_tttt_ffff_iiii_llll_llll, is also available for setting the fill character; see
               _mmmm_aaaa_nnnn_iiii_pppp(3C++).

          _c_====_s_...._ffff_iiii_llll_llll_((((_))))
               Returns the ``fill character'' format state variable.

          _l_====_s_...._ffff_llll_aaaa_gggg_ssss_((((_))))
               Returns the current format flags.

          _l_====_s_...._ffff_llll_aaaa_gggg_ssss_((((_ffff_))))
               Resets all the format flags to those specified in _f and returns
               the previous settings.

          _o_i_====_s_...._pppp_rrrr_eeee_cccc_iiii_ssss_iiii_oooo_nnnn_((((_i_))))
               Sets the _pppp_rrrr_eeee_cccc_iiii_ssss_iiii_oooo_nnnn format state variable to _i and returns the
               previous value.  This variable controls the number of
               significant digits inserted by the floating point inserter.
               The default is 6.  A parameterized manipulator, _ssss_eeee_tttt_pppp_rrrr_eeee_cccc_iiii_ssss_iiii_oooo_nnnn,
               is also available for setting the precision; see _mmmm_aaaa_nnnn_iiii_pppp(3C++).

          _i_====_s_...._pppp_rrrr_eeee_cccc_iiii_ssss_iiii_oooo_nnnn_((((_))))
               Returns the _pppp_rrrr_eeee_cccc_iiii_ssss_iiii_oooo_nnnn format state variable.

          _l_====_s_...._ssss_eeee_tttt_ffff_((((_b_))))
               Turns on in _s the format flags marked in _b and returns the
               previous settings.  A parameterized manipulator, _ssss_eeee_tttt_iiii_oooo_ssss_ffff_llll_aaaa_gggg_ssss,
               performs the same function; see _mmmm_aaaa_nnnn_iiii_pppp(3C++).




                                                                        PPPPaaaaggggeeee 6666






IIIIOOOOSSSS((((3333CCCC++++++++))))                                                            IIIIOOOOSSSS((((3333CCCC++++++++))))



          _l_====_s_...._ssss_eeee_tttt_ffff_((((_b_,,,,_f_))))
               Resets in _s only the format flags specified by _f to the
               settings marked in _b, and returns the previous settings.  That
               is, the format flags specified by _f are cleared in _s, then
               reset to be those marked in _b.  For example, to change the
               conversion base in _s to be _hhhh_eeee_xxxx, one could write:
               _s_...._ssss_eeee_tttt_ffff_((((_iiii_oooo_ssss_::::_::::_hhhh_eeee_xxxx_,,,,_iiii_oooo_ssss_::::_::::_bbbb_aaaa_ssss_eeee_ffff_iiii_eeee_llll_dddd_)))).  _iiii_oooo_ssss_::::_::::_bbbb_aaaa_ssss_eeee_ffff_iiii_eeee_llll_dddd specifies the
               conversion base bits as candidates for change, and _iiii_oooo_ssss_::::_::::_hhhh_eeee_xxxx
               specifies the new value.  _s_...._ssss_eeee_tttt_ffff_((((_0000_,,,,_f_)))) will clear all the bits
               specified by _f, as will a parameterized manipulator,
               _rrrr_eeee_ssss_eeee_tttt_iiii_oooo_ssss_ffff_llll_aaaa_gggg_ssss; see _mmmm_aaaa_nnnn_iiii_pppp(3C++).

          _l_====_s_...._uuuu_nnnn_ssss_eeee_tttt_ffff_((((_b_))))
               Unsets in _s the bits set in _b and returns the previous
               settings.

          _o_i_====_s_...._wwww_iiii_dddd_tttt_hhhh_((((_i_))))
               Sets the _f_i_e_l_d _w_i_d_t_h format variable to _i and returns the
               previous value.  When the field width is zero (the default),
               inserters will insert only as many characters as necessary to
               represent the value being inserted.  When the field width is
               non-zero, the inserters will insert at least that many
               characters, using the fill character to pad the value, if the
               value being inserted requires fewer than _f_i_e_l_d-_w_i_d_t_h characters
               to be represented.  However, the numeric inserters never
               truncate values, so if the value being inserted will not fit in
               _f_i_e_l_d-_w_i_d_t_h characters, more than _f_i_e_l_d-_w_i_d_t_h characters will
               be output.  The field width is always interpreted as a mininum
               number of characters; there is no direct way to specify a
               maximum number of characters.  The _f_i_e_l_d-_w_i_d_t_h format variable
               is reset to the default (zero) after each insertion or
               extraction, and in this sense it behaves as a parameter for
               insertions and extractions.  A parameterized manipulator, _ssss_eeee_tttt_wwww,
               is also available for setting the width; see _mmmm_aaaa_nnnn_iiii_pppp(3C++).

          _i_====_s_...._wwww_iiii_dddd_tttt_hhhh_((((_))))
               Returns the _f_i_e_l_d-_w_i_d_t_h format variable.

   UUUUsssseeeerrrr----ddddeeeeffffiiiinnnneeeedddd FFFFoooorrrrmmmmaaaatttt FFFFllllaaaaggggssss
     Class _iiii_oooo_ssss can be used as a base class for derived classes that require
     additional format flags or variables.  The iostream library provides
     several functions to do this.  The two static member functions
     _iiii_oooo_ssss_::::_::::_xxxx_aaaa_llll_llll_oooo_cccc and _iiii_oooo_ssss_::::_::::_bbbb_iiii_tttt_aaaa_llll_llll_oooo_cccc, allow several such classes to be used
     together without interference.

          _b_====_iiii_oooo_ssss_::::_::::_bbbb_iiii_tttt_aaaa_llll_llll_oooo_cccc_((((_))))
               Returns a _llll_oooo_nnnn_gggg with a single, previously unallocated, bit set.
               This allows users who need an additional flag to acquire one,
               and pass it as an argument to _iiii_oooo_ssss_::::_::::_ssss_eeee_tttt_ffff_((((_)))), for example.






                                                                        PPPPaaaaggggeeee 7777






IIIIOOOOSSSS((((3333CCCC++++++++))))                                                            IIIIOOOOSSSS((((3333CCCC++++++++))))



          _i_====_iiii_oooo_ssss_::::_::::_xxxx_aaaa_llll_llll_oooo_cccc_((((_))))
               Returns a previously unused index into an array of words
               available for use as format state variables by derived classes.

          _l_====_s_...._iiii_wwww_oooo_rrrr_dddd_((((_i_))))
               When _i is an index allocated by _iiii_oooo_ssss_::::_::::_xxxx_aaaa_llll_llll_oooo_cccc, _iiii_wwww_oooo_rrrr_dddd_((((_)))) returns a
               reference to the _ith user-defined word.

          _v_p_====_s_...._pppp_wwww_oooo_rrrr_dddd_((((_i_))))
               When _i is an index allocated by _iiii_oooo_ssss_::::_::::_xxxx_aaaa_llll_llll_oooo_cccc, _pppp_wwww_oooo_rrrr_dddd_((((_)))) returns a
               reference to the _ith user-defined word.  _pppp_wwww_oooo_rrrr_dddd_((((_)))) is the same as
               _iiii_wwww_oooo_rrrr_dddd except that it is typed differently.

   OOOOtttthhhheeeerrrr mmmmeeeemmmmbbbbeeeerrrrssss::::
          _s_b_====_s_...._rrrr_dddd_bbbb_uuuu_ffff_((((_))))
               Returns a pointer to the _ssss_tttt_rrrr_eeee_aaaa_mmmm_bbbb_uuuu_ffff associated with _s when _s was
               constructed.

          _iiii_oooo_ssss_::::_::::_ssss_yyyy_nnnn_cccc______wwww_iiii_tttt_hhhh______ssss_tttt_dddd_iiii_oooo_((((_))))
               Solves problems that arise when mixing stdio and iostreams.
               The first time it is called it will reset the standard
               iostreams (_cccc_iiii_nnnn, _cccc_oooo_uuuu_tttt, _cccc_eeee_rrrr_rrrr, _cccc_llll_oooo_gggg) to be streams using
               _ssss_tttt_dddd_iiii_oooo_bbbb_uuuu_ffffs.  After that, input and output using these streams
               may be mixed with input and output using the corresponding
               _FFFF_IIII_LLLL_EEEEs (_ssss_tttt_dddd_iiii_nnnn, _ssss_tttt_dddd_oooo_uuuu_tttt, and _ssss_tttt_dddd_eeee_rrrr_rrrr) and will be properly
               synchronized.  _ssss_yyyy_nnnn_cccc______wwww_iiii_tttt_hhhh______ssss_tttt_dddd_iiii_oooo_((((_)))) makes _cccc_oooo_uuuu_tttt and _cccc_eeee_rrrr_rrrr unit
               buffered (see _iiii_oooo_ssss_::::_::::_uuuu_nnnn_iiii_tttt_bbbb_uuuu_ffff and _iiii_oooo_ssss_::::_::::_ssss_tttt_dddd_iiii_oooo above).  Invoking
               _ssss_yyyy_nnnn_cccc______wwww_iiii_tttt_hhhh______ssss_tttt_dddd_iiii_oooo_((((_)))) degrades performance a variable amount,
               depending on the length of the strings being inserted (shorter
               strings incur a larger performance hit).

          _o_o_s_p_====_s_...._tttt_iiii_eeee_((((_o_s_p_))))
               Sets the _tttt_iiii_eeee variable to _o_s_p, and returns its previous value.
               This variable supports automatic ``flushing'' of _iiii_oooo_sssss.  If the
               _tttt_iiii_eeee variable is non-null and an _iiii_oooo_ssss needs more characters or
               has characters to be consumed, the _iiii_oooo_ssss pointed at by the tie
               variable is flushed.  By default, _cccc_iiii_nnnn is tied initially to _cccc_oooo_uuuu_tttt
               so that attempts to get more characters from standard input
               result in flushing standard output.  Additionally, _cccc_eeee_rrrr_rrrr and
               _cccc_llll_oooo_gggg are tied to _cccc_oooo_uuuu_tttt by default.  For other _iiii_oooo_sssss, the tie
               variable is set to zero by default.

          _o_s_p_====_s_...._tttt_iiii_eeee_((((_))))
               Returns the _tttt_iiii_eeee variable.

   BBBBuuuuiiiilllltttt----iiiinnnn MMMMaaaannnniiiippppuuuullllaaaattttoooorrrrssss::::
     Some convenient manipulators (functions that take an _iiii_oooo_ssss_&&&&, an _iiii_ssss_tttt_rrrr_eeee_aaaa_mmmm_&&&&,
     or an _oooo_ssss_tttt_rrrr_eeee_aaaa_mmmm_&&&& and return their argument; see _mmmm_aaaa_nnnn_iiii_pppp(3C++)) are:
     _s_r_<<<<_<<<<_dddd_eeee_cccc
     _s_r_>>>>_>>>>_dddd_eeee_cccc
          These set the conversion base format flag to 10.




                                                                        PPPPaaaaggggeeee 8888






IIIIOOOOSSSS((((3333CCCC++++++++))))                                                            IIIIOOOOSSSS((((3333CCCC++++++++))))



     _s_r_<<<<_<<<<_hhhh_eeee_xxxx
     _s_r_>>>>_>>>>_hhhh_eeee_xxxx
          These set the conversion base format flag to 16.

     _s_r_<<<<_<<<<_oooo_cccc_tttt
     _s_r_>>>>_>>>>_oooo_cccc_tttt
          These set the conversion base format flag to 8.

          _s_r_>>>>_>>>>_wwww_ssss
               Extracts whitespace characters.  See _iiii_ssss_tttt_rrrr_eeee_aaaa_mmmm(3C++).

          _s_r_<<<<_<<<<_eeee_nnnn_dddd_llll
               Ends a line by inserting a newline character and flushing.  See
               _oooo_ssss_tttt_rrrr_eeee_aaaa_mmmm(3C++).

          _s_r_<<<<_<<<<_eeee_nnnn_dddd_ssss
               Ends a string by inserting a null (0) character.  See
               _oooo_ssss_tttt_rrrr_eeee_aaaa_mmmm(3C++).

          _s_r_<<<<_<<<<_ffff_llll_uuuu_ssss_hhhh
               Flushes _oooo_uuuu_tttt_ssss.  See _oooo_ssss_tttt_rrrr_eeee_aaaa_mmmm(3C++).

     Several parameterized manipulators that operate on _iiii_oooo_ssss objects are
     described in _mmmm_aaaa_nnnn_iiii_pppp(3C++):  _ssss_eeee_tttt_wwww, _ssss_eeee_tttt_ffff_iiii_llll_llll, _ssss_eeee_tttt_pppp_rrrr_eeee_cccc_iiii_ssss_iiii_oooo_nnnn, _ssss_eeee_tttt_iiii_oooo_ssss_ffff_llll_aaaa_gggg_ssss, and
     _rrrr_eeee_ssss_eeee_tttt_iiii_oooo_ssss_ffff_llll_aaaa_gggg_ssss.

     The _ssss_tttt_rrrr_eeee_aaaa_mmmm_bbbb_uuuu_ffff associated with an _iiii_oooo_ssss may be manipulated by other methods
     than through the _iiii_oooo_ssss.  For example, characters may be stored in a
     queuelike _ssss_tttt_rrrr_eeee_aaaa_mmmm_bbbb_uuuu_ffff through an _oooo_ssss_tttt_rrrr_eeee_aaaa_mmmm while they are being fetched
     through an _iiii_ssss_tttt_rrrr_eeee_aaaa_mmmm.  Or for efficiency some part of a program may choose
     to do _ssss_tttt_rrrr_eeee_aaaa_mmmm_bbbb_uuuu_ffff operations directly rather than through the _iiii_oooo_ssss.  In most
     cases the program does not have to worry about this possibility, because
     an _iiii_oooo_ssss never saves information about the internal state of a _ssss_tttt_rrrr_eeee_aaaa_mmmm_bbbb_uuuu_ffff.
     For example, if the _ssss_tttt_rrrr_eeee_aaaa_mmmm_bbbb_uuuu_ffff is repositioned between extraction
     operations the extraction (input) will proceed normally.

CCCCAAAAVVVVEEEEAAAATTTTSSSS
     The need for _ssss_yyyy_nnnn_cccc______wwww_iiii_tttt_hhhh______ssss_tttt_dddd_iiii_oooo is a wart.  The old stream package did this
     as a default, but in the iostream package unbuffered _ssss_tttt_dddd_iiii_oooo_bbbb_uuuu_ffffs are too
     inefficient to be the default.

     The stream package had a constructor that took a _FFFF_IIII_LLLL_EEEE_**** argument.  This is
     now replaced by _ssss_tttt_dddd_iiii_oooo_ssss_tttt_rrrr_eeee_aaaa_mmmm.  It is not declared even as an obsolete form
     to avoid having _iiii_oooo_ssss_tttt_rrrr_eeee_aaaa_mmmm_...._hhhh depend on _ssss_tttt_dddd_iiii_oooo_...._hhhh.

     The old stream package allowed copying of streams.  This is disallowed by
     the iostream package.  However, objects of type _iiii_ssss_tttt_rrrr_eeee_aaaa_mmmm______wwww_iiii_tttt_hhhh_aaaa_ssss_ssss_iiii_gggg_nnnn,
     _oooo_ssss_tttt_rrrr_eeee_aaaa_mmmm______wwww_iiii_tttt_hhhh_aaaa_ssss_ssss_iiii_gggg_nnnn, and _iiii_oooo_ssss_tttt_rrrr_eeee_aaaa_mmmm______wwww_iiii_tttt_hhhh_aaaa_ssss_ssss_iiii_gggg_nnnn can be assigned to.  Old code
     using copying can usually be rewritten to use pointers or these classes.
     (The standard streams _cccc_iiii_nnnn, _cccc_oooo_uuuu_tttt, _cccc_eeee_rrrr_rrrr, and _cccc_llll_oooo_gggg are members of
     ``withassign'' classes, so they can be assigned to, as in
     _cccc_iiii_nnnn _==== _iiii_nnnn_pppp_uuuu_tttt_ffff_ssss_tttt_rrrr_eeee_aaaa_mmmm.)



                                                                        PPPPaaaaggggeeee 9999






IIIIOOOOSSSS((((3333CCCC++++++++))))                                                            IIIIOOOOSSSS((((3333CCCC++++++++))))



SSSSEEEEEEEE AAAALLLLSSSSOOOO
     _iiii_oooo_ssss_tttt_rrrr_eeee_aaaa_mmmm(3C++), _ssss_tttt_rrrr_eeee_aaaa_mmmm_bbbb_uuuu_ffff(3C++), _iiii_ssss_tttt_rrrr_eeee_aaaa_mmmm(3C++), _oooo_ssss_tttt_rrrr_eeee_aaaa_mmmm(3C++),
     _mmmm_aaaa_nnnn_iiii_pppp(3C++).




















































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