// Locale support (codecvt) -*- C++ -*-
	
	// Copyright (C) 2000-2013 Free Software Foundation, Inc.
	//
	// This file is part of the GNU ISO C++ Library.  This library is free
	// software; you can redistribute it and/or modify it under the
	// terms of the GNU General Public License as published by the
	// Free Software Foundation; either version 3, or (at your option)
	// any later version.
	
	// This library is distributed in the hope that it will be useful,
	// but WITHOUT ANY WARRANTY; without even the implied warranty of
	// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	// GNU General Public License for more details.
	
	// Under Section 7 of GPL version 3, you are granted additional
	// permissions described in the GCC Runtime Library Exception, version
	// 3.1, as published by the Free Software Foundation.
	
	// You should have received a copy of the GNU General Public License and
	// a copy of the GCC Runtime Library Exception along with this program;
	// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
	// <http://www.gnu.org/licenses/>.
	
	/** @file bits/codecvt.h
	 *  This is an internal header file, included by other library headers.
	 *  Do not attempt to use it directly. @headername{locale}
	 */
	
	//
	// ISO C++ 14882: 22.2.1.5 Template class codecvt
	//
	
	// Written by Benjamin Kosnik <bkoz@redhat.com>
	
	#ifndef _CODECVT_H
	#define _CODECVT_H 1
	
	#pragma GCC system_header
	
	namespace std _GLIBCXX_VISIBILITY(default)
	{
	_GLIBCXX_BEGIN_NAMESPACE_VERSION
	
	  /// Empty base class for codecvt facet [22.2.1.5].
	  class codecvt_base
	  {
	  public:
	    enum result
	    {
	      ok,
	      partial,
	      error,
	      noconv
	    };
	  };
	
	  /**
	   *  @brief  Common base for codecvt functions.
	   *
	   *  This template class provides implementations of the public functions
	   *  that forward to the protected virtual functions.
	   *
	   *  This template also provides abstract stubs for the protected virtual
	   *  functions.
	  */
	  template<typename _InternT, typename _ExternT, typename _StateT>
	    class __codecvt_abstract_base
	    : public locale::facet, public codecvt_base
	    {
	    public:
	      // Types:
	      typedef codecvt_base::result	result;
	      typedef _InternT			intern_type;
	      typedef _ExternT			extern_type;
	      typedef _StateT			state_type;
	
	      // 22.2.1.5.1 codecvt members
	      /**
	       *  @brief  Convert from internal to external character set.
	       *
	       *  Converts input string of intern_type to output string of
	       *  extern_type.  This is analogous to wcsrtombs.  It does this by
	       *  calling codecvt::do_out.
	       *
	       *  The source and destination character sets are determined by the
	       *  facet's locale, internal and external types.
	       *
	       *  The characters in [from,from_end) are converted and written to
	       *  [to,to_end).  from_next and to_next are set to point to the
	       *  character following the last successfully converted character,
	       *  respectively.  If the result needed no conversion, from_next and
	       *  to_next are not affected.
	       *
	       *  The @a state argument should be initialized if the input is at the
	       *  beginning and carried from a previous call if continuing
	       *  conversion.  There are no guarantees about how @a state is used.
	       *
	       *  The result returned is a member of codecvt_base::result.  If
	       *  all the input is converted, returns codecvt_base::ok.  If no
	       *  conversion is necessary, returns codecvt_base::noconv.  If
	       *  the input ends early or there is insufficient space in the
	       *  output, returns codecvt_base::partial.  Otherwise the
	       *  conversion failed and codecvt_base::error is returned.
	       *
	       *  @param  __state  Persistent conversion state data.
	       *  @param  __from  Start of input.
	       *  @param  __from_end  End of input.
	       *  @param  __from_next  Returns start of unconverted data.
	       *  @param  __to  Start of output buffer.
	       *  @param  __to_end  End of output buffer.
	       *  @param  __to_next  Returns start of unused output area.
	       *  @return  codecvt_base::result.
	      */
	      result
	      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
	      {
		return this->do_out(__state, __from, __from_end, __from_next,
				    __to, __to_end, __to_next);
	      }
	
	      /**
	       *  @brief  Reset conversion state.
	       *
	       *  Writes characters to output that would restore @a state to initial
	       *  conditions.  The idea is that if a partial conversion occurs, then
	       *  the converting the characters written by this function would leave
	       *  the state in initial conditions, rather than partial conversion
	       *  state.  It does this by calling codecvt::do_unshift().
	       *
	       *  For example, if 4 external characters always converted to 1 internal
	       *  character, and input to in() had 6 external characters with state
	       *  saved, this function would write two characters to the output and
	       *  set the state to initialized conditions.
	       *
	       *  The source and destination character sets are determined by the
	       *  facet's locale, internal and external types.
	       *
	       *  The result returned is a member of codecvt_base::result.  If the
	       *  state could be reset and data written, returns codecvt_base::ok.  If
	       *  no conversion is necessary, returns codecvt_base::noconv.  If the
	       *  output has insufficient space, returns codecvt_base::partial.
	       *  Otherwise the reset failed and codecvt_base::error is returned.
	       *
	       *  @param  __state  Persistent conversion state data.
	       *  @param  __to  Start of output buffer.
	       *  @param  __to_end  End of output buffer.
	       *  @param  __to_next  Returns start of unused output area.
	       *  @return  codecvt_base::result.
	      */
	      result
	      unshift(state_type& __state, extern_type* __to, extern_type* __to_end,
		      extern_type*& __to_next) const
	      { return this->do_unshift(__state, __to,__to_end,__to_next); }
	
	      /**
	       *  @brief  Convert from external to internal character set.
	       *
	       *  Converts input string of extern_type to output string of
	       *  intern_type.  This is analogous to mbsrtowcs.  It does this by
	       *  calling codecvt::do_in.
	       *
	       *  The source and destination character sets are determined by the
	       *  facet's locale, internal and external types.
	       *
	       *  The characters in [from,from_end) are converted and written to
	       *  [to,to_end).  from_next and to_next are set to point to the
	       *  character following the last successfully converted character,
	       *  respectively.  If the result needed no conversion, from_next and
	       *  to_next are not affected.
	       *
	       *  The @a state argument should be initialized if the input is at the
	       *  beginning and carried from a previous call if continuing
	       *  conversion.  There are no guarantees about how @a state is used.
	       *
	       *  The result returned is a member of codecvt_base::result.  If
	       *  all the input is converted, returns codecvt_base::ok.  If no
	       *  conversion is necessary, returns codecvt_base::noconv.  If
	       *  the input ends early or there is insufficient space in the
	       *  output, returns codecvt_base::partial.  Otherwise the
	       *  conversion failed and codecvt_base::error is returned.
	       *
	       *  @param  __state  Persistent conversion state data.
	       *  @param  __from  Start of input.
	       *  @param  __from_end  End of input.
	       *  @param  __from_next  Returns start of unconverted data.
	       *  @param  __to  Start of output buffer.
	       *  @param  __to_end  End of output buffer.
	       *  @param  __to_next  Returns start of unused output area.
	       *  @return  codecvt_base::result.
	      */
	      result
	      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
	      {
		return this->do_in(__state, __from, __from_end, __from_next,
				   __to, __to_end, __to_next);
	      }
	
	      int
	      encoding() const throw()
	      { return this->do_encoding(); }
	
	      bool
	      always_noconv() const throw()
	      { return this->do_always_noconv(); }
	
	      int
	      length(state_type& __state, const extern_type* __from,
		     const extern_type* __end, size_t __max) const
	      { return this->do_length(__state, __from, __end, __max); }
	
	      int
	      max_length() const throw()
	      { return this->do_max_length(); }
	
	    protected:
	      explicit
	      __codecvt_abstract_base(size_t __refs = 0) : locale::facet(__refs) { }
	
	      virtual
	      ~__codecvt_abstract_base() { }
	
	      /**
	       *  @brief  Convert from internal to external character set.
	       *
	       *  Converts input string of intern_type to output string of
	       *  extern_type.  This function is a hook for derived classes to change
	       *  the value returned.  @see out for more information.
	      */
	      virtual result
	      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 = 0;
	
	      virtual result
	      do_unshift(state_type& __state, extern_type* __to,
			 extern_type* __to_end, extern_type*& __to_next) const = 0;
	
	      virtual result
	      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 = 0;
	
	      virtual int
	      do_encoding() const throw() = 0;
	
	      virtual bool
	      do_always_noconv() const throw() = 0;
	
	      virtual int
	      do_length(state_type&, const extern_type* __from,
			const extern_type* __end, size_t __max) const = 0;
	
	      virtual int
	      do_max_length() const throw() = 0;
	    };
	
	
	
	  /**
	   *  @brief  Primary class template codecvt.
	   *  @ingroup locales
	   *
	   *  NB: Generic, mostly useless implementation.
	   *
	  */
	   template<typename _InternT, typename _ExternT, typename _StateT>
	    class codecvt
	    : public __codecvt_abstract_base<_InternT, _ExternT, _StateT>
	    {
	    public:
	      // Types:
	      typedef codecvt_base::result	result;
	      typedef _InternT			intern_type;
	      typedef _ExternT			extern_type;
	      typedef _StateT			state_type;
	
	    protected:
	      __c_locale			_M_c_locale_codecvt;
	
	    public:
	      static locale::id			id;
	
	      explicit
	      codecvt(size_t __refs = 0)
	      : __codecvt_abstract_base<_InternT, _ExternT, _StateT> (__refs),
		_M_c_locale_codecvt(0)
	      { }
	
	      explicit
	      codecvt(__c_locale __cloc, size_t __refs = 0);
	
	    protected:
	      virtual
	      ~codecvt() { }
	
	      virtual result
	      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;
	
	      virtual result
	      do_unshift(state_type& __state, extern_type* __to,
			 extern_type* __to_end, extern_type*& __to_next) const;
	
	      virtual result
	      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;
	
	      virtual int
	      do_encoding() const throw();
	
	      virtual bool
	      do_always_noconv() const throw();
	
	      virtual int
	      do_length(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, typename _StateT>
	    locale::id codecvt<_InternT, _ExternT, _StateT>::id;
	
	  /// class codecvt<char, char, mbstate_t> specialization.
	  template<>
	    class codecvt<char, char, mbstate_t>
	    : public __codecvt_abstract_base<char, char, mbstate_t>
	    {
	    public:
	      // Types:
	      typedef char			intern_type;
	      typedef char			extern_type;
	      typedef mbstate_t			state_type;
	
	    protected:
	      __c_locale			_M_c_locale_codecvt;
	
	    public:
	      static locale::id id;
	
	      explicit
	      codecvt(size_t __refs = 0);
	
	      explicit
	      codecvt(__c_locale __cloc, size_t __refs = 0);
	
	    protected:
	      virtual
	      ~codecvt();
	
	      virtual result
	      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;
	
	      virtual result
	      do_unshift(state_type& __state, extern_type* __to,
			 extern_type* __to_end, extern_type*& __to_next) const;
	
	      virtual result
	      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;
	
	      virtual int
	      do_encoding() const throw();
	
	      virtual bool
	      do_always_noconv() const throw();
	
	      virtual int
	      do_length(state_type&, const extern_type* __from,
			const extern_type* __end, size_t __max) const;
	
	      virtual int
	      do_max_length() const throw();
	  };
	
	#ifdef _GLIBCXX_USE_WCHAR_T
	  /// class codecvt<wchar_t, char, mbstate_t> specialization.
	  template<>
	    class codecvt<wchar_t, char, mbstate_t>
	    : public __codecvt_abstract_base<wchar_t, char, mbstate_t>
	    {
	    public:
	      // Types:
	      typedef wchar_t			intern_type;
	      typedef char			extern_type;
	      typedef mbstate_t			state_type;
	
	    protected:
	      __c_locale			_M_c_locale_codecvt;
	
	    public:
	      static locale::id			id;
	
	      explicit
	      codecvt(size_t __refs = 0);
	
	      explicit
	      codecvt(__c_locale __cloc, size_t __refs = 0);
	
	    protected:
	      virtual
	      ~codecvt();
	
	      virtual result
	      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;
	
	      virtual result
	      do_unshift(state_type& __state,
			 extern_type* __to, extern_type* __to_end,
			 extern_type*& __to_next) const;
	
	      virtual result
	      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;
	
	      virtual
	      int do_encoding() const throw();
	
	      virtual
	      bool do_always_noconv() const throw();
	
	      virtual
	      int do_length(state_type&, const extern_type* __from,
			    const extern_type* __end, size_t __max) const;
	
	      virtual int
	      do_max_length() const throw();
	    };
	#endif //_GLIBCXX_USE_WCHAR_T
	
	  /// class codecvt_byname [22.2.1.6].
	  template<typename _InternT, typename _ExternT, typename _StateT>
	    class codecvt_byname : public codecvt<_InternT, _ExternT, _StateT>
	    {
	    public:
	      explicit
	      codecvt_byname(const char* __s, size_t __refs = 0)
	      : codecvt<_InternT, _ExternT, _StateT>(__refs)
	      {
		if (__builtin_strcmp(__s, "C") != 0
		    && __builtin_strcmp(__s, "POSIX") != 0)
		  {
		    this->_S_destroy_c_locale(this->_M_c_locale_codecvt);
		    this->_S_create_c_locale(this->_M_c_locale_codecvt, __s);
		  }
	      }
	
	    protected:
	      virtual
	      ~codecvt_byname() { }
	    };
	
	  // Inhibit implicit instantiations for required instantiations,
	  // which are defined via explicit instantiations elsewhere.
	#if _GLIBCXX_EXTERN_TEMPLATE
	  extern template class codecvt_byname<char, char, mbstate_t>;
	
	  extern template
	    const codecvt<char, char, mbstate_t>&
	    use_facet<codecvt<char, char, mbstate_t> >(const locale&);
	
	  extern template
	    bool
	    has_facet<codecvt<char, char, mbstate_t> >(const locale&);
	
	#ifdef _GLIBCXX_USE_WCHAR_T
	  extern template class codecvt_byname<wchar_t, char, mbstate_t>;
	
	  extern template
	    const codecvt<wchar_t, char, mbstate_t>&
	    use_facet<codecvt<wchar_t, char, mbstate_t> >(const locale&);
	
	  extern template
	    bool
	    has_facet<codecvt<wchar_t, char, mbstate_t> >(const locale&);
	#endif
	#endif
	
	_GLIBCXX_END_NAMESPACE_VERSION
	} // namespace std
	
	#endif // _CODECVT_H