codecvt_specializations.h

俄罗斯高人Mamaich的Pocket gcc编译器（运行在PocketPC上）的全部源代码。

      virtual int 
      do_length(const state_type&, const extern_type* __from, 
		const extern_type* __end, size_t __max) const;

      virtual int 
      do_max_length() const throw();
    };

  template<typename _InternT, typename _ExternT>
    locale::id 
    codecvt<_InternT, _ExternT, __enc_traits>::id;

  // This adaptor works around the signature problems of the second
  // argument to iconv():  SUSv2 and others use 'const char**', but glibc 2.2
  // uses 'char**', which matches the POSIX 1003.1-2001 standard.
  // Using this adaptor, g++ will do the work for us.
  template<typename _T>
    inline size_t
    __iconv_adaptor(size_t(*__func)(iconv_t, _T, size_t*, char**, size_t*),
                    iconv_t __cd, char** __inbuf, size_t* __inbytes,
                    char** __outbuf, size_t* __outbytes)
    { return __func(__cd, (_T)__inbuf, __inbytes, __outbuf, __outbytes); }

  template<typename _InternT, typename _ExternT>
    codecvt_base::result
    codecvt<_InternT, _ExternT, __enc_traits>::
    do_out(state_type& __state, const intern_type* __from, 
	   const intern_type* __from_end, const intern_type*& __from_next,
	   extern_type* __to, extern_type* __to_end,
	   extern_type*& __to_next) const
    {
      result __ret = codecvt_base::error;
      if (__state._M_good())
	{
	  typedef state_type::__desc_type	__desc_type;
	  const __desc_type* __desc = __state._M_get_out_descriptor();
	  const size_t __fmultiple = sizeof(intern_type);
	  size_t __fbytes = __fmultiple * (__from_end - __from);
	  const size_t __tmultiple = sizeof(extern_type);
	  size_t __tbytes = __tmultiple * (__to_end - __to); 
	  
	  // Argument list for iconv specifies a byte sequence. Thus,
	  // all to/from arrays must be brutally casted to char*.
	  char* __cto = reinterpret_cast<char*>(__to);
	  char* __cfrom;
	  size_t __conv;

	  // Some encodings need a byte order marker as the first item
	  // in the byte stream, to designate endian-ness. The default
	  // value for the byte order marker is NULL, so if this is
	  // the case, it's not necessary and we can just go on our
	  // merry way.
	  int __int_bom = __state._M_get_internal_bom();
	  if (__int_bom)
	    {	  
	      size_t __size = __from_end - __from;
	      intern_type* __cfixed = static_cast<intern_type*>(__builtin_alloca(sizeof(intern_type) * (__size + 1)));
	      __cfixed[0] = static_cast<intern_type>(__int_bom);
	      char_traits<intern_type>::copy(__cfixed + 1, __from, __size);
	      __cfrom = reinterpret_cast<char*>(__cfixed);
	      __conv = __iconv_adaptor(iconv, *__desc, &__cfrom,
                                        &__fbytes, &__cto, &__tbytes); 
	    }
	  else
	    {
	      intern_type* __cfixed = const_cast<intern_type*>(__from);
	      __cfrom = reinterpret_cast<char*>(__cfixed);
	      __conv = __iconv_adaptor(iconv, *__desc, &__cfrom, &__fbytes, 
				       &__cto, &__tbytes); 
	    }

	  if (__conv != size_t(-1))
	    {
	      __from_next = reinterpret_cast<const intern_type*>(__cfrom);
	      __to_next = reinterpret_cast<extern_type*>(__cto);
	      __ret = codecvt_base::ok;
	    }
	  else 
	    {
	      if (__fbytes < __fmultiple * (__from_end - __from))
		{
		  __from_next = reinterpret_cast<const intern_type*>(__cfrom);
		  __to_next = reinterpret_cast<extern_type*>(__cto);
		  __ret = codecvt_base::partial;
		}
	      else
		__ret = codecvt_base::error;
	    }
	}
      return __ret; 
    }

  template<typename _InternT, typename _ExternT>
    codecvt_base::result
    codecvt<_InternT, _ExternT, __enc_traits>::
    do_unshift(state_type& __state, extern_type* __to, 
	       extern_type* __to_end, extern_type*& __to_next) const
    {
      result __ret = codecvt_base::error;
      if (__state._M_good())
	{
	  typedef state_type::__desc_type	__desc_type;
	  const __desc_type* __desc = __state._M_get_in_descriptor();
	  const size_t __tmultiple = sizeof(intern_type);
	  size_t __tlen = __tmultiple * (__to_end - __to); 
	  
	  // Argument list for iconv specifies a byte sequence. Thus,
	  // all to/from arrays must be brutally casted to char*.
	  char* __cto = reinterpret_cast<char*>(__to);
	  size_t __conv = __iconv_adaptor(iconv,*__desc, NULL, NULL,
                                          &__cto, &__tlen); 
	  
	  if (__conv != size_t(-1))
	    {
	      __to_next = reinterpret_cast<extern_type*>(__cto);
	      if (__tlen == __tmultiple * (__to_end - __to))
		__ret = codecvt_base::noconv;
	      else if (__tlen == 0)
		__ret = codecvt_base::ok;
	      else
		__ret = codecvt_base::partial;
	    }
	  else 
	    __ret = codecvt_base::error;
	}
      return __ret; 
    }
   
  template<typename _InternT, typename _ExternT>
    codecvt_base::result
    codecvt<_InternT, _ExternT, __enc_traits>::
    do_in(state_type& __state, const extern_type* __from, 
	  const extern_type* __from_end, const extern_type*& __from_next,
	  intern_type* __to, intern_type* __to_end, 
	  intern_type*& __to_next) const
    { 
      result __ret = codecvt_base::error;
      if (__state._M_good())
	{
	  typedef state_type::__desc_type	__desc_type;
	  const __desc_type* __desc = __state._M_get_in_descriptor();
	  const size_t __fmultiple = sizeof(extern_type);
	  size_t __flen = __fmultiple * (__from_end - __from);
	  const size_t __tmultiple = sizeof(intern_type);
	  size_t __tlen = __tmultiple * (__to_end - __to); 
	  
	  // Argument list for iconv specifies a byte sequence. Thus,
	  // all to/from arrays must be brutally casted to char*.
	  char* __cto = reinterpret_cast<char*>(__to);
	  char* __cfrom;
	  size_t __conv;

	  // Some encodings need a byte order marker as the first item
	  // in the byte stream, to designate endian-ness. The default
	  // value for the byte order marker is NULL, so if this is
	  // the case, it's not necessary and we can just go on our
	  // merry way.
	  int __ext_bom = __state._M_get_external_bom();
	  if (__ext_bom)
	    {	  
	      size_t __size = __from_end - __from;
	      extern_type* __cfixed =  static_cast<extern_type*>(__builtin_alloca(sizeof(extern_type) * (__size + 1)));
	      __cfixed[0] = static_cast<extern_type>(__ext_bom);
	      char_traits<extern_type>::copy(__cfixed + 1, __from, __size);
	      __cfrom = reinterpret_cast<char*>(__cfixed);
	      __conv = __iconv_adaptor(iconv, *__desc, &__cfrom,
                                       &__flen, &__cto, &__tlen); 
	    }
	  else
	    {
	      extern_type* __cfixed = const_cast<extern_type*>(__from);
	      __cfrom = reinterpret_cast<char*>(__cfixed);
	      __conv = __iconv_adaptor(iconv, *__desc, &__cfrom,
                                       &__flen, &__cto, &__tlen); 
	    }

	  
	  if (__conv != size_t(-1))
	    {
	      __from_next = reinterpret_cast<const extern_type*>(__cfrom);
	      __to_next = reinterpret_cast<intern_type*>(__cto);
	      __ret = codecvt_base::ok;
	    }
	  else 
	    {
	      if (__flen < static_cast<size_t>(__from_end - __from))
		{
		  __from_next = reinterpret_cast<const extern_type*>(__cfrom);
		  __to_next = reinterpret_cast<intern_type*>(__cto);
		  __ret = codecvt_base::partial;
		}
	      else
		__ret = codecvt_base::error;
	    }
	}
      return __ret; 
    }
  
  template<typename _InternT, typename _ExternT>
    int 
    codecvt<_InternT, _ExternT, __enc_traits>::
    do_encoding() const throw()
    {
      int __ret = 0;
      if (sizeof(_ExternT) <= sizeof(_InternT))
	__ret = sizeof(_InternT)/sizeof(_ExternT);
      return __ret; 
    }
  
  template<typename _InternT, typename _ExternT>
    bool 
    codecvt<_InternT, _ExternT, __enc_traits>::
    do_always_noconv() const throw()
    { return false; }
  
  template<typename _InternT, typename _ExternT>
    int 
    codecvt<_InternT, _ExternT, __enc_traits>::
    do_length(const state_type&, const extern_type* __from, 
	      const extern_type* __end, size_t __max) const
    { return min(__max, static_cast<size_t>(__end - __from)); }

#ifdef _GLIBCPP_RESOLVE_LIB_DEFECTS
// 74.  Garbled text for codecvt::do_max_length
  template<typename _InternT, typename _ExternT>
    int 
    codecvt<_InternT, _ExternT, __enc_traits>::
    do_max_length() const throw()
    { return 1; }
#endif