字元特性char_traits定義，及其特化版本char_traits，char_traits

// iosfwd standard header#if     _MSC_VER > 1000#pragma once#endif#ifndef _IOSFWD_#define _IOSFWD_#include <cstdio>#include <cstring>#include <cwchar>#include <xstddef>#ifdef  _MSC_VER#pragma pack(push,8)#endif  /* _MSC_VER */_STD_BEGIN                // STREAM POSITIONING TYPES (from <streambuf>)typedef long streamoff;const streamoff _BADOFF = -1;typedef int streamsize;extern _CRTIMP const fpos_t _Fpz;                // TEMPLATE CLASS fpos (from <streambuf>)template<class _St>        class fpos {        typedef fpos<_St> _Myt;public:#ifdef  _MT        fpos(streamoff _O = 0)                : _Off(_O), _Fpos(_Fpz)                {_Lockit _Lk;                _State = _Stz; }#else        fpos(streamoff _O = 0)                : _Off(_O), _Fpos(_Fpz), _State(_Stz) {}#endif        fpos(_St _S, fpos_t _F)                : _Off(0), _Fpos(_F), _State(_S) {}        _St state() const                {return (_State); }        void state(_St _S)                {_State = _S; }        fpos_t get_fpos_t() const                {return (_Fpos); }        operator streamoff() const                {return (_Off + _FPOSOFF(_Fpos)); }        streamoff operator-(const _Myt& _R) const                {return ((streamoff)*this - (streamoff)_R); }        _Myt& operator+=(streamoff _O)                {_Off += _O;                return (*this); }        _Myt& operator-=(streamoff _O)                {_Off -= _O;                return (*this); }        _Myt operator+(streamoff _O) const                {_Myt _Tmp = *this;                return (_Tmp += _O); }        _Myt operator-(streamoff _O) const                {_Myt _Tmp = *this;                return (_Tmp -= _O); }        bool operator==(const _Myt& _R) const                {return ((streamoff)*this == (streamoff)_R); }        bool operator!=(const _Myt& _R) const                {return (!(*this == _R)); }private:        static _St _Stz;        streamoff _Off;        fpos_t _Fpos;        _St _State;        };template<class _St>        _St fpos<_St>::_Stz;typedef fpos<mbstate_t> streampos;typedef streampos wstreampos;                // TEMPLATE STRUCT char_traits (FROM <string>)template<class _E>        struct char_traits {        typedef _E char_type;        typedef _E int_type;        typedef streampos pos_type;        typedef streamoff off_type;        typedef mbstate_t state_type;        static void __cdecl assign(_E& _X, const _E& _Y)                {_X = _Y; }        static bool __cdecl eq(const _E& _X, const _E& _Y)                {return (_X == _Y); }        static bool __cdecl lt(const _E& _X, const _E& _Y)                {return (_X < _Y); }        static int __cdecl compare(const _E *_U, const _E *_V, size_t _N)                {for (size_t _I = 0; _I < _N; ++_I, ++_U, ++_V)                        if (!eq(*_U, *_V))                                return (lt(*_U, *_V) ? -1 : +1);                return (0); }        static size_t __cdecl length(const _E *_U)                {size_t _N;                for (_N = 0; !eq(*_U, _E(0)); ++_U)                        ++_N;                return (_N); }        static _E * __cdecl copy(_E *_U, const _E *_V, size_t _N)                {_E *_S = _U;                for (; 0 < _N; --_N, ++_U, ++_V)                        assign(*_U, *_V);                return (_S); }        static const _E * __cdecl find(const _E *_U, size_t _N,                const _E& _C)                {for (; 0 < _N; --_N, ++_U)                        if (eq(*_U, _C))                                return (_U);                return (0); }        static _E * __cdecl move(_E *_U, const _E *_V, size_t _N)                {_E *_Ans = _U;                if (_V < _U && _U < _V + _N)                        for (_U += _N, _V += _N; 0 < _N; --_N)                                assign(*--_U, *--_V);                else                        for (; 0 < _N; --_N, ++_U, ++_V)                                assign(*_U, *_V);                return (_Ans); }        static _E * __cdecl assign(_E *_U, size_t _N, const _E& _C)                {_E *_Ans = _U;                for (; 0 < _N; --_N, ++_U)                        assign(*_U, _C);                return (_Ans); }        static _E __cdecl to_char_type(const int_type& _C)                {return ((_E)_C); }        static int_type __cdecl to_int_type(const _E& _C)                {return ((int_type)_C); }        static bool __cdecl eq_int_type(const int_type& _X,                const int_type& _Y)                {return (_X == _Y); }        static int_type __cdecl eof()                {return (EOF); }        static int_type __cdecl not_eof(const int_type& _C)                {return (_C != eof() ? _C : !eof()); }        };                // STRUCT char_traits<wchar_t>template<> struct _CRTIMP char_traits<wchar_t> {        typedef wchar_t _E;        typedef _E char_type;   // for overloads        typedef wint_t int_type;        typedef streampos pos_type;        typedef streamoff off_type;        typedef mbstate_t state_type;        static void __cdecl assign(_E& _X, const _E& _Y)                {_X = _Y; }        static bool __cdecl eq(const _E& _X, const _E& _Y)                {return (_X == _Y); }        static bool __cdecl lt(const _E& _X, const _E& _Y)                {return (_X < _Y); }        static int __cdecl compare(const _E *_U, const _E *_V, size_t _N)                {return (wmemcmp(_U, _V, _N)); }        static size_t __cdecl length(const _E *_U)                {return (wcslen(_U)); }        static _E *__cdecl copy(_E *_U, const _E *_V, size_t _N)                {return (wmemcpy(_U, _V, _N)); }        static const _E * __cdecl find(const _E *_U, size_t _N,                const _E& _C)                {return ((const _E *)wmemchr(_U, _C, _N)); }        static _E * __cdecl move(_E *_U, const _E *_V, size_t _N)                {return (wmemmove(_U, _V, _N)); }        static _E * __cdecl assign(_E *_U, size_t _N, const _E& _C)                {return (wmemset(_U, _C, _N)); }        static _E __cdecl to_char_type(const int_type& _C)                {return ((_E)_C); }        static int_type __cdecl to_int_type(const _E& _C)                {return ((int_type)_C); }        static bool __cdecl eq_int_type(const int_type& _X,                const int_type& _Y)                {return (_X == _Y); }        static int_type __cdecl eof()                {return (WEOF); }        static int_type __cdecl not_eof(const int_type& _C)                {return (_C != eof() ? _C : !eof()); }        };                // STRUCT char_traits<char> (FROM <string>)template<> struct _CRTIMP char_traits<char> {        typedef char _E;        typedef _E char_type;        typedef int int_type;        typedef streampos pos_type;        typedef streamoff off_type;        typedef mbstate_t state_type;        static void __cdecl assign(_E& _X, const _E& _Y)                {_X = _Y; }        static bool __cdecl eq(const _E& _X, const _E& _Y)                {return (_X == _Y); }        static bool __cdecl lt(const _E& _X, const _E& _Y)                {return (_X < _Y); }        static int __cdecl compare(const _E *_U, const _E *_V, size_t _N)                {return (memcmp(_U, _V, _N)); }        static size_t __cdecl length(const _E *_U)                {return (strlen(_U)); }        static _E * __cdecl copy(_E *_U, const _E *_V, size_t _N)                {return ((_E *)memcpy(_U, _V, _N)); }        static const _E * __cdecl find(const _E *_U, size_t _N,                const _E& _C)                {return ((const _E *)memchr(_U, _C, _N)); }        static _E * __cdecl move(_E *_U, const _E *_V, size_t _N)                {return ((_E *)memmove(_U, _V, _N)); }        static _E * __cdecl assign(_E *_U, size_t _N, const _E& _C)                {return ((_E *)memset(_U, _C, _N)); }        static _E __cdecl to_char_type(const int_type& _C)                {return ((_E)_C); }        static int_type __cdecl to_int_type(const _E& _C)                {return ((int_type)((unsigned char)_C)); }        static bool __cdecl eq_int_type(const int_type& _X,                const int_type& _Y)                {return (_X == _Y); }        static int_type __cdecl eof()                {return (EOF); }        static int_type __cdecl not_eof(const int_type& _C)                {return (_C != eof() ? _C : !eof()); }        };                // FORWARD REFERENCEStemplate<class T>        class allocator;class ios_base;template<class _E, class _Tr = char_traits<_E> >        class basic_ios;template<class _E, class _Tr = char_traits<_E> >        class istreambuf_iterator;template<class _E, class _Tr = char_traits<_E> >        class ostreambuf_iterator;template<class _E, class _Tr = char_traits<_E> >        class basic_streambuf;template<class _E, class _Tr = char_traits<_E> >        class basic_istream;template<class _E, class _Tr = char_traits<_E> >        class basic_ostream;template<class _E, class _Tr = char_traits<_E> >        class basic_iostream;template<class _E, class _Tr = char_traits<_E>,        class _A = allocator<_E> >        class basic_stringbuf;template<class _E, class _Tr = char_traits<_E>,        class _A = allocator<_E> >        class basic_istringstream;template<class _E, class _Tr = char_traits<_E>,        class _A = allocator<_E> >        class basic_ostringstream;template<class _E, class _Tr = char_traits<_E>,        class _A = allocator<_E> >        class basic_stringstream;template<class _E, class _Tr = char_traits<_E> >        class basic_filebuf;template<class _E, class _Tr = char_traits<_E> >        class basic_ifstream;template<class _E, class _Tr = char_traits<_E> >        class basic_ofstream;template<class _E, class _Tr = char_traits<_E> >        class basic_fstream;                // char TYPEDEFStypedef basic_ios<char, char_traits<char> > ios;typedef basic_streambuf<char, char_traits<char> > streambuf;typedef basic_istream<char, char_traits<char> > istream;typedef basic_ostream<char, char_traits<char> > ostream;typedef basic_iostream<char, char_traits<char> > iostream;typedef basic_stringbuf<char, char_traits<char>,        allocator<char> > stringbuf;typedef basic_istringstream<char, char_traits<char>,        allocator<char> > istringstream;typedef basic_ostringstream<char, char_traits<char>,        allocator<char> > ostringstream;typedef basic_stringstream<char, char_traits<char>,        allocator<char> > stringstream;typedef basic_filebuf<char, char_traits<char> > filebuf;typedef basic_ifstream<char, char_traits<char> > ifstream;typedef basic_ofstream<char, char_traits<char> > ofstream;typedef basic_fstream<char, char_traits<char> > fstream;                // wchar_t TYPEDEFStypedef basic_ios<wchar_t, char_traits<wchar_t> > wios;typedef basic_streambuf<wchar_t, char_traits<wchar_t> >        wstreambuf;typedef basic_istream<wchar_t, char_traits<wchar_t> > wistream;typedef basic_ostream<wchar_t, char_traits<wchar_t> > wostream;typedef basic_iostream<wchar_t, char_traits<wchar_t> > wiostream;typedef basic_stringbuf<wchar_t, char_traits<wchar_t>,        allocator<wchar_t> > wstringbuf;typedef basic_istringstream<wchar_t, char_traits<wchar_t>,        allocator<wchar_t> > wistringstream;typedef basic_ostringstream<wchar_t, char_traits<wchar_t>,        allocator<wchar_t> > wostringstream;typedef basic_stringstream<wchar_t, char_traits<wchar_t>,        allocator<wchar_t> > wstringstream;typedef basic_filebuf<wchar_t, char_traits<wchar_t> > wfilebuf;typedef basic_ifstream<wchar_t, char_traits<wchar_t> > wifstream;typedef basic_ofstream<wchar_t, char_traits<wchar_t> > wofstream;typedef basic_fstream<wchar_t, char_traits<wchar_t> > wfstream;#ifdef  _DLLtemplate<class _E, class _II >    class num_get;template<class _E, class _OI >    class num_put;template<class _E>    class collate;typedef num_get<char, istreambuf_iterator<char, char_traits<char> > > numget;typedef num_get<wchar_t, istreambuf_iterator<wchar_t, char_traits<wchar_t> > >                                                                                                                                          wnumget;typedef num_put<char, ostreambuf_iterator<char, char_traits<char> > > numput;typedef num_put<wchar_t, ostreambuf_iterator<wchar_t, char_traits<wchar_t> > >                                                                                                                                          wnumput;typedef collate<char> ncollate;typedef collate<wchar_t> wcollate;#endif_STD_END#ifdef  _MSC_VER#pragma pack(pop)#endif  /* _MSC_VER */#endif /* _IOSFWD_ *//* * Copyright (c) 1995 by P.J. Plauger.  ALL RIGHTS RESERVED.  * Consult your license regarding permissions and restrictions. */