usr/arc-buildroot-linux-uclibc/include/c++/6.1.1/bits/locale_conv.h - toolchains/quantenna - Git at Google

 // wstring_convert implementation -*- C++ -*-

 // Copyright (C) 2015-2016 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/locale_conv.h
  *  This is an internal header file, included by other library headers.
  *  Do not attempt to use it directly. @headername{locale}
  */

 #ifndef _LOCALE_CONV_H
 #define _LOCALE_CONV_H 1

 #if __cplusplus < 201103L
 # include <bits/c++0x_warning.h>
 #else

 #include <streambuf>
 #include "stringfwd.h"
 #include "allocator.h"
 #include "codecvt.h"
 #include "unique_ptr.h"

 namespace std _GLIBCXX_VISIBILITY(default)
 {
 _GLIBCXX_BEGIN_NAMESPACE_VERSION

   /**
    * @addtogroup locales
    * @{
    */

   template<typename _OutStr, typename _InChar, typename _Codecvt,
 	   typename _State, typename _Fn>
     bool
     __do_str_codecvt(const _InChar* __first, const _InChar* __last,
 		     _OutStr& __outstr, const _Codecvt& __cvt, _State& __state,
 		     size_t& __count, _Fn __fn)
     {
       if (__first == __last)
 	{
 	  __outstr.clear();
 	  __count = 0;
 	  return true;
 	}

       size_t __outchars = 0;
       auto __next = __first;
       const auto __maxlen = __cvt.max_length() + 1;

       codecvt_base::result __result;
       do
 	{
 	  __outstr.resize(__outstr.size() + (__last - __next) * __maxlen);
 	  auto __outnext = &__outstr.front() + __outchars;
 	  auto const __outlast = &__outstr.back() + 1;
 	  __result = (__cvt.*__fn)(__state, __next, __last, __next,
 					__outnext, __outlast, __outnext);
 	  __outchars = __outnext - &__outstr.front();
 	}
       while (__result == codecvt_base::partial && __next != __last
 	     && (__outstr.size() - __outchars) < __maxlen);

       if (__result == codecvt_base::error)
 	return false;

       if (__result == codecvt_base::noconv)
 	{
 	  __outstr.assign(__first, __last);
 	  __count = __last - __first;
 	}
       else
 	{
 	  __outstr.resize(__outchars);
 	  __count = __next - __first;
 	}

       return true;
     }

   // Convert narrow character string to wide.
   template<typename _CharT, typename _Traits, typename _Alloc, typename _State>
     inline bool
     __str_codecvt_in(const char* __first, const char* __last,
 		     basic_string<_CharT, _Traits, _Alloc>& __outstr,
 		     const codecvt<_CharT, char, _State>& __cvt,
 		     _State& __state, size_t& __count)
     {
       using _Codecvt = codecvt<_CharT, char, _State>;
       using _ConvFn
 	= codecvt_base::result
 	  (_Codecvt::*)(_State&, const char*, const char*, const char*&,
 			_CharT*, _CharT*, _CharT*&) const;
       _ConvFn __fn = &codecvt<_CharT, char, _State>::in;
       return __do_str_codecvt(__first, __last, __outstr, __cvt, __state,
 			      __count, __fn);
     }

   template<typename _CharT, typename _Traits, typename _Alloc, typename _State>
     inline bool
     __str_codecvt_in(const char* __first, const char* __last,
 		     basic_string<_CharT, _Traits, _Alloc>& __outstr,
 		     const codecvt<_CharT, char, _State>& __cvt)
     {
       _State __state = {};
       size_t __n;
       return __str_codecvt_in(__first, __last, __outstr, __cvt, __state, __n);
     }

   // Convert wide character string to narrow.
   template<typename _CharT, typename _Traits, typename _Alloc, typename _State>
     inline bool
     __str_codecvt_out(const _CharT* __first, const _CharT* __last,
 		      basic_string<char, _Traits, _Alloc>& __outstr,
 		      const codecvt<_CharT, char, _State>& __cvt,
 		      _State& __state, size_t& __count)
     {
       using _Codecvt = codecvt<_CharT, char, _State>;
       using _ConvFn
 	= codecvt_base::result
 	  (_Codecvt::*)(_State&, const _CharT*, const _CharT*, const _CharT*&,
 			char*, char*, char*&) const;
       _ConvFn __fn = &codecvt<_CharT, char, _State>::out;
       return __do_str_codecvt(__first, __last, __outstr, __cvt, __state,
 			      __count, __fn);
     }

   template<typename _CharT, typename _Traits, typename _Alloc, typename _State>
     inline bool
     __str_codecvt_out(const _CharT* __first, const _CharT* __last,
 		      basic_string<char, _Traits, _Alloc>& __outstr,
 		      const codecvt<_CharT, char, _State>& __cvt)
     {
       _State __state = {};
       size_t __n;
       return __str_codecvt_out(__first, __last, __outstr, __cvt, __state, __n);
     }

 #ifdef _GLIBCXX_USE_WCHAR_T

 _GLIBCXX_BEGIN_NAMESPACE_CXX11

   /// String conversions
   template<typename _Codecvt, typename _Elem = wchar_t,
 	   typename _Wide_alloc = allocator<_Elem>,
 	   typename _Byte_alloc = allocator<char>>
     class wstring_convert
     {
     public:
       typedef basic_string<char, char_traits<char>, _Byte_alloc>   byte_string;
       typedef basic_string<_Elem, char_traits<_Elem>, _Wide_alloc> wide_string;
       typedef typename _Codecvt::state_type 			   state_type;
       typedef typename wide_string::traits_type::int_type	   int_type;

       /** Default constructor.
        *
        * @param  __pcvt The facet to use for conversions.
        *
        * Takes ownership of @p __pcvt and will delete it in the destructor.
        */
       explicit
       wstring_convert(_Codecvt* __pcvt = new _Codecvt()) : _M_cvt(__pcvt)
       {
 	if (!_M_cvt)
 	  __throw_logic_error("wstring_convert");
       }

       /** Construct with an initial converstion state.
        *
        * @param  __pcvt The facet to use for conversions.
        * @param  __state Initial conversion state.
        *
        * Takes ownership of @p __pcvt and will delete it in the destructor.
        * The object's conversion state will persist between conversions.
        */
       wstring_convert(_Codecvt* __pcvt, state_type __state)
       : _M_cvt(__pcvt), _M_state(__state), _M_with_cvtstate(true)
       {
 	if (!_M_cvt)
 	  __throw_logic_error("wstring_convert");
       }

       /** Construct with error strings.
        *
        * @param  __byte_err A string to return on failed conversions.
        * @param  __wide_err A wide string to return on failed conversions.
        */
       explicit
       wstring_convert(const byte_string& __byte_err,
 		      const wide_string& __wide_err = wide_string())
       : _M_cvt(new _Codecvt),
 	_M_byte_err_string(__byte_err), _M_wide_err_string(__wide_err),
 	_M_with_strings(true)
       {
 	if (!_M_cvt)
 	  __throw_logic_error("wstring_convert");
       }

       ~wstring_convert() = default;

       // _GLIBCXX_RESOLVE_LIB_DEFECTS
       // 2176. Special members for wstring_convert and wbuffer_convert
       wstring_convert(const wstring_convert&) = delete;
       wstring_convert& operator=(const wstring_convert&) = delete;

       /// @{ Convert from bytes.
       wide_string
       from_bytes(char __byte)
       {
 	char __bytes[2] = { __byte };
 	return from_bytes(__bytes, __bytes+1);
       }

       wide_string
       from_bytes(const char* __ptr)
       { return from_bytes(__ptr, __ptr+char_traits<char>::length(__ptr)); }

       wide_string
       from_bytes(const byte_string& __str)
       {
 	auto __ptr = __str.data();
 	return from_bytes(__ptr, __ptr + __str.size());
       }

       wide_string
       from_bytes(const char* __first, const char* __last)
       {
 	if (!_M_with_cvtstate)
 	  _M_state = state_type();
 	wide_string __out{ _M_wide_err_string.get_allocator() };
 	if (__str_codecvt_in(__first, __last, __out, *_M_cvt, _M_state,
 			     _M_count))
 	  return __out;
 	if (_M_with_strings)
 	  return _M_wide_err_string;
 	__throw_range_error("wstring_convert::from_bytes");
       }
       /// @}

       /// @{ Convert to bytes.
       byte_string
       to_bytes(_Elem __wchar)
       {
 	_Elem __wchars[2] = { __wchar };
 	return to_bytes(__wchars, __wchars+1);
       }

       byte_string
       to_bytes(const _Elem* __ptr)
       {
 	return to_bytes(__ptr, __ptr+wide_string::traits_type::length(__ptr));
       }

       byte_string
       to_bytes(const wide_string& __wstr)
       {
 	auto __ptr = __wstr.data();
 	return to_bytes(__ptr, __ptr + __wstr.size());
       }

       byte_string
       to_bytes(const _Elem* __first, const _Elem* __last)
       {
 	if (!_M_with_cvtstate)
 	  _M_state = state_type();
 	byte_string __out{ _M_byte_err_string.get_allocator() };
 	if (__str_codecvt_out(__first, __last, __out, *_M_cvt, _M_state,
 			      _M_count))
 	  return __out;
 	if (_M_with_strings)
 	  return _M_byte_err_string;
 	__throw_range_error("wstring_convert::to_bytes");
       }
       /// @}

       // _GLIBCXX_RESOLVE_LIB_DEFECTS
       // 2174. wstring_convert::converted() should be noexcept
       /// The number of elements successfully converted in the last conversion.
       size_t converted() const noexcept { return _M_count; }

       /// The final conversion state of the last conversion.
       state_type state() const { return _M_state; }

     private:
       unique_ptr<_Codecvt>	_M_cvt;
       byte_string		_M_byte_err_string;
       wide_string		_M_wide_err_string;
       state_type		_M_state = state_type();
       size_t			_M_count = 0;
       bool			_M_with_cvtstate = false;
       bool			_M_with_strings = false;
     };

 _GLIBCXX_END_NAMESPACE_CXX11

   /// Buffer conversions
   template<typename _Codecvt, typename _Elem = wchar_t,
 	   typename _Tr = char_traits<_Elem>>
     class wbuffer_convert : public basic_streambuf<_Elem, _Tr>
     {
       typedef basic_streambuf<_Elem, _Tr> _Wide_streambuf;

     public:
       typedef typename _Codecvt::state_type state_type;

       /** Default constructor.
        *
        * @param  __bytebuf The underlying byte stream buffer.
        * @param  __pcvt    The facet to use for conversions.
        * @param  __state   Initial conversion state.
        *
        * Takes ownership of @p __pcvt and will delete it in the destructor.
        */
       explicit
       wbuffer_convert(streambuf* __bytebuf = 0, _Codecvt* __pcvt = new _Codecvt,
 		      state_type __state = state_type())
       : _M_buf(__bytebuf), _M_cvt(__pcvt), _M_state(__state)
       {
 	if (!_M_cvt)
 	  __throw_logic_error("wbuffer_convert");

 	_M_always_noconv = _M_cvt->always_noconv();

 	if (_M_buf)
 	  {
 	    this->setp(_M_put_area, _M_put_area + _S_buffer_length);
 	    this->setg(_M_get_area + _S_putback_length,
 		       _M_get_area + _S_putback_length,
 		       _M_get_area + _S_putback_length);
 	  }
       }

       ~wbuffer_convert() = default;

       // _GLIBCXX_RESOLVE_LIB_DEFECTS
       // 2176. Special members for wstring_convert and wbuffer_convert
       wbuffer_convert(const wbuffer_convert&) = delete;
       wbuffer_convert& operator=(const wbuffer_convert&) = delete;

       streambuf* rdbuf() const noexcept { return _M_buf; }

       streambuf*
       rdbuf(streambuf *__bytebuf) noexcept
       {
 	auto __prev = _M_buf;
 	_M_buf = __bytebuf;
 	return __prev;
       }

       /// The conversion state following the last conversion.
       state_type state() const noexcept { return _M_state; }

     protected:
       int
       sync()
       { return _M_buf && _M_conv_put() && _M_buf->pubsync() ? 0 : -1; }

       typename _Wide_streambuf::int_type
       overflow(typename _Wide_streambuf::int_type __out)
       {
 	if (!_M_buf || !_M_conv_put())
 	  return _Tr::eof();
 	else if (!_Tr::eq_int_type(__out, _Tr::eof()))
 	  return this->sputc(__out);
 	return _Tr::not_eof(__out);
       }

       typename _Wide_streambuf::int_type
       underflow()
       {
 	if (!_M_buf)
 	  return _Tr::eof();

 	if (this->gptr() < this->egptr() || (_M_buf && _M_conv_get()))
 	  return _Tr::to_int_type(*this->gptr());
 	else
 	  return _Tr::eof();
       }

       streamsize
       xsputn(const typename _Wide_streambuf::char_type* __s, streamsize __n)
       {
 	if (!_M_buf || __n == 0)
 	  return 0;
 	streamsize __done = 0;
 	do
 	{
 	  auto __nn = std::min<streamsize>(this->epptr() - this->pptr(),
 					   __n - __done);
 	  _Tr::copy(this->pptr(), __s + __done, __nn);
 	  this->pbump(__nn);
 	  __done += __nn;
 	} while (__done < __n && _M_conv_put());
 	return __done;
       }

     private:
       // fill the get area from converted contents of the byte stream buffer
       bool
       _M_conv_get()
       {
 	const streamsize __pb1 = this->gptr() - this->eback();
 	const streamsize __pb2 = _S_putback_length;
 	const streamsize __npb = std::min(__pb1, __pb2);

 	_Tr::move(_M_get_area + _S_putback_length - __npb,
 		  this->gptr() - __npb, __npb);

 	streamsize __nbytes = sizeof(_M_get_buf) - _M_unconv;
 	__nbytes = std::min(__nbytes, _M_buf->in_avail());
 	if (__nbytes < 1)
 	  __nbytes == 1;
 	__nbytes = _M_buf->sgetn(_M_get_buf + _M_unconv, __nbytes);
 	if (__nbytes < 1)
 	  return false;
 	__nbytes += _M_unconv;

 	// convert _M_get_buf into _M_get_area

 	_Elem* __outbuf = _M_get_area + _S_putback_length;
 	_Elem* __outnext = __outbuf;
 	const char* __bnext = _M_get_buf;

 	codecvt_base::result __result;
 	if (_M_always_noconv)
 	  __result = codecvt_base::noconv;
 	else
 	  {
 	    _Elem* __outend = _M_get_area + _S_buffer_length;

 	    __result = _M_cvt->in(_M_state,
 				  __bnext, __bnext + __nbytes, __bnext,
 				  __outbuf, __outend, __outnext);
 	  }

 	if (__result == codecvt_base::noconv)
 	  {
 	    // cast is safe because noconv means _Elem is same type as char
 	    auto __get_buf = reinterpret_cast<const _Elem*>(_M_get_buf);
 	    _Tr::copy(__outbuf, __get_buf, __nbytes);
 	    _M_unconv = 0;
 	    return true;
 	  }

 	if ((_M_unconv = _M_get_buf + __nbytes - __bnext))
 	  char_traits<char>::move(_M_get_buf, __bnext, _M_unconv);

 	this->setg(__outbuf, __outbuf, __outnext);

 	return __result != codecvt_base::error;
       }

       // unused
       bool
       _M_put(...)
       { return false; }

       bool
       _M_put(const char* __p, streamsize __n)
       {
 	if (_M_buf->sputn(__p, __n) < __n)
 	  return false;
       }

       // convert the put area and write to the byte stream buffer
       bool
       _M_conv_put()
       {
 	_Elem* const __first = this->pbase();
 	const _Elem* const __last = this->pptr();
 	const streamsize __pending = __last - __first;

 	if (_M_always_noconv)
 	  return _M_put(__first, __pending);

 	char __outbuf[2 * _S_buffer_length];

 	const _Elem* __next = __first;
 	const _Elem* __start;
 	do
 	  {
 	    __start = __next;
 	    char* __outnext = __outbuf;
 	    char* const __outlast = __outbuf + sizeof(__outbuf);
 	    auto __result = _M_cvt->out(_M_state, __next, __last, __next,
 					__outnext, __outlast, __outnext);
 	    if (__result == codecvt_base::error)
 	      return false;
 	    else if (__result == codecvt_base::noconv)
 	      return _M_put(__next, __pending);

 	    if (!_M_put(__outbuf, __outnext - __outbuf))
 	      return false;
 	  }
 	while (__next != __last && __next != __start);

 	if (__next != __last)
 	  _Tr::move(__first, __next, __last - __next);

 	this->pbump(__first - __next);
 	return __next != __first;
       }

       streambuf*		_M_buf;
       unique_ptr<_Codecvt>	_M_cvt;
       state_type		_M_state;

       static const streamsize	_S_buffer_length = 32;
       static const streamsize	_S_putback_length = 3;
       _Elem                     _M_put_area[_S_buffer_length];
       _Elem                     _M_get_area[_S_buffer_length];
       streamsize		_M_unconv = 0;
       char			_M_get_buf[_S_buffer_length-_S_putback_length];
       bool			_M_always_noconv;
     };

 #endif  // _GLIBCXX_USE_WCHAR_T

   /// @} group locales

 _GLIBCXX_END_NAMESPACE_VERSION
 } // namespace

 #endif // __cplusplus

 #endif /* _LOCALE_CONV_H */
	// wstring_convert implementation -- C++ --

	// Copyright (C) 2015-2016 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/locale_conv.h
	* This is an internal header file, included by other library headers.
	* Do not attempt to use it directly. @headername{locale}
	*/

	#ifndef _LOCALE_CONV_H
	#define _LOCALE_CONV_H 1

	#if __cplusplus < 201103L
	# include <bits/c++0x_warning.h>
	#else

	#include <streambuf>
	#include "stringfwd.h"
	#include "allocator.h"
	#include "codecvt.h"
	#include "unique_ptr.h"

	namespace std _GLIBCXX_VISIBILITY(default)
	{
	_GLIBCXX_BEGIN_NAMESPACE_VERSION

	/**
	* @addtogroup locales
	* @{
	*/

	template<typename _OutStr, typename _InChar, typename _Codecvt,
	typename _State, typename _Fn>
	bool
	__do_str_codecvt(const _InChar* __first, const _InChar* __last,
	_OutStr& __outstr, const _Codecvt& __cvt, _State& __state,
	size_t& __count, _Fn __fn)
	{
	if (__first == __last)
	{
	__outstr.clear();
	__count = 0;
	return true;
	}

	size_t __outchars = 0;
	auto __next = __first;
	const auto __maxlen = __cvt.max_length() + 1;

	codecvt_base::result __result;
	do
	{
	__outstr.resize(__outstr.size() + (__last - __next) * __maxlen);
	auto __outnext = &__outstr.front() + __outchars;
	auto const __outlast = &__outstr.back() + 1;
	__result = (__cvt.*__fn)(__state, __next, __last, __next,
	__outnext, __outlast, __outnext);
	__outchars = __outnext - &__outstr.front();
	}
	while (__result == codecvt_base::partial && __next != __last
	&& (__outstr.size() - __outchars) < __maxlen);

	if (__result == codecvt_base::error)
	return false;

	if (__result == codecvt_base::noconv)
	{
	__outstr.assign(__first, __last);
	__count = __last - __first;
	}
	else
	{
	__outstr.resize(__outchars);
	__count = __next - __first;
	}

	return true;
	}

	// Convert narrow character string to wide.
	template<typename _CharT, typename _Traits, typename _Alloc, typename _State>
	inline bool
	__str_codecvt_in(const char* __first, const char* __last,
	basic_string<_CharT, _Traits, _Alloc>& __outstr,
	const codecvt<_CharT, char, _State>& __cvt,
	_State& __state, size_t& __count)
	{
	using _Codecvt = codecvt<_CharT, char, _State>;
	using _ConvFn
	= codecvt_base::result
	(_Codecvt::)(_State&, const char, const char, const char&,
	_CharT, _CharT, _CharT*&) const;
	_ConvFn __fn = &codecvt<_CharT, char, _State>::in;
	return __do_str_codecvt(__first, __last, __outstr, __cvt, __state,
	__count, __fn);
	}

	template<typename _CharT, typename _Traits, typename _Alloc, typename _State>
	inline bool
	__str_codecvt_in(const char* __first, const char* __last,
	basic_string<_CharT, _Traits, _Alloc>& __outstr,
	const codecvt<_CharT, char, _State>& __cvt)
	{
	_State __state = {};
	size_t __n;
	return __str_codecvt_in(__first, __last, __outstr, __cvt, __state, __n);
	}

	// Convert wide character string to narrow.
	template<typename _CharT, typename _Traits, typename _Alloc, typename _State>
	inline bool
	__str_codecvt_out(const _CharT* __first, const _CharT* __last,
	basic_string<char, _Traits, _Alloc>& __outstr,
	const codecvt<_CharT, char, _State>& __cvt,
	_State& __state, size_t& __count)
	{
	using _Codecvt = codecvt<_CharT, char, _State>;
	using _ConvFn
	= codecvt_base::result
	(_Codecvt::)(_State&, const _CharT, const _CharT, const _CharT&,
	char, char, char*&) const;
	_ConvFn __fn = &codecvt<_CharT, char, _State>::out;
	return __do_str_codecvt(__first, __last, __outstr, __cvt, __state,
	__count, __fn);
	}

	template<typename _CharT, typename _Traits, typename _Alloc, typename _State>
	inline bool
	__str_codecvt_out(const _CharT* __first, const _CharT* __last,
	basic_string<char, _Traits, _Alloc>& __outstr,
	const codecvt<_CharT, char, _State>& __cvt)
	{
	_State __state = {};
	size_t __n;
	return __str_codecvt_out(__first, __last, __outstr, __cvt, __state, __n);
	}

	#ifdef _GLIBCXX_USE_WCHAR_T

	_GLIBCXX_BEGIN_NAMESPACE_CXX11

	/// String conversions
	template<typename _Codecvt, typename _Elem = wchar_t,
	typename _Wide_alloc = allocator<_Elem>,
	typename _Byte_alloc = allocator<char>>
	class wstring_convert
	{
	public:
	typedef basic_string<char, char_traits<char>, _Byte_alloc> byte_string;
	typedef basic_string<_Elem, char_traits<_Elem>, _Wide_alloc> wide_string;
	typedef typename _Codecvt::state_type state_type;
	typedef typename wide_string::traits_type::int_type int_type;

	/** Default constructor.
	*
	* @param __pcvt The facet to use for conversions.
	*
	* Takes ownership of @p __pcvt and will delete it in the destructor.
	*/
	explicit
	wstring_convert(_Codecvt* __pcvt = new _Codecvt()) : _M_cvt(__pcvt)
	{
	if (!_M_cvt)
	__throw_logic_error("wstring_convert");
	}

	/** Construct with an initial converstion state.
	*
	* @param __pcvt The facet to use for conversions.
	* @param __state Initial conversion state.
	*
	* Takes ownership of @p __pcvt and will delete it in the destructor.
	* The object's conversion state will persist between conversions.
	*/
	wstring_convert(_Codecvt* __pcvt, state_type __state)
	: _M_cvt(__pcvt), _M_state(__state), _M_with_cvtstate(true)
	{
	if (!_M_cvt)
	__throw_logic_error("wstring_convert");
	}

	/** Construct with error strings.
	*
	* @param __byte_err A string to return on failed conversions.
	* @param __wide_err A wide string to return on failed conversions.
	*/
	explicit
	wstring_convert(const byte_string& __byte_err,
	const wide_string& __wide_err = wide_string())
	: _M_cvt(new _Codecvt),
	_M_byte_err_string(__byte_err), _M_wide_err_string(__wide_err),
	_M_with_strings(true)
	{
	if (!_M_cvt)
	__throw_logic_error("wstring_convert");
	}

	~wstring_convert() = default;

	// _GLIBCXX_RESOLVE_LIB_DEFECTS
	// 2176. Special members for wstring_convert and wbuffer_convert
	wstring_convert(const wstring_convert&) = delete;
	wstring_convert& operator=(const wstring_convert&) = delete;

	/// @{ Convert from bytes.
	wide_string
	from_bytes(char __byte)
	{
	char __bytes[2] = { __byte };
	return from_bytes(__bytes, __bytes+1);
	}

	wide_string
	from_bytes(const char* __ptr)
	{ return from_bytes(__ptr, __ptr+char_traits<char>::length(__ptr)); }

	wide_string
	from_bytes(const byte_string& __str)
	{
	auto __ptr = __str.data();
	return from_bytes(__ptr, __ptr + __str.size());
	}

	wide_string
	from_bytes(const char* __first, const char* __last)
	{
	if (!_M_with_cvtstate)
	_M_state = state_type();
	wide_string __out{ _M_wide_err_string.get_allocator() };
	if (__str_codecvt_in(__first, __last, __out, *_M_cvt, _M_state,
	_M_count))
	return __out;
	if (_M_with_strings)
	return _M_wide_err_string;
	__throw_range_error("wstring_convert::from_bytes");
	}
	/// @}

	/// @{ Convert to bytes.
	byte_string
	to_bytes(_Elem __wchar)
	{
	_Elem __wchars[2] = { __wchar };
	return to_bytes(__wchars, __wchars+1);
	}

	byte_string
	to_bytes(const _Elem* __ptr)
	{
	return to_bytes(__ptr, __ptr+wide_string::traits_type::length(__ptr));
	}

	byte_string
	to_bytes(const wide_string& __wstr)
	{
	auto __ptr = __wstr.data();
	return to_bytes(__ptr, __ptr + __wstr.size());
	}

	byte_string
	to_bytes(const _Elem* __first, const _Elem* __last)
	{
	if (!_M_with_cvtstate)
	_M_state = state_type();
	byte_string __out{ _M_byte_err_string.get_allocator() };
	if (__str_codecvt_out(__first, __last, __out, *_M_cvt, _M_state,
	_M_count))
	return __out;
	if (_M_with_strings)
	return _M_byte_err_string;
	__throw_range_error("wstring_convert::to_bytes");
	}
	/// @}

	// _GLIBCXX_RESOLVE_LIB_DEFECTS
	// 2174. wstring_convert::converted() should be noexcept
	/// The number of elements successfully converted in the last conversion.
	size_t converted() const noexcept { return _M_count; }

	/// The final conversion state of the last conversion.
	state_type state() const { return _M_state; }

	private:
	unique_ptr<_Codecvt> _M_cvt;
	byte_string _M_byte_err_string;
	wide_string _M_wide_err_string;
	state_type _M_state = state_type();
	size_t _M_count = 0;
	bool _M_with_cvtstate = false;
	bool _M_with_strings = false;
	};

	_GLIBCXX_END_NAMESPACE_CXX11

	/// Buffer conversions
	template<typename _Codecvt, typename _Elem = wchar_t,
	typename _Tr = char_traits<_Elem>>
	class wbuffer_convert : public basic_streambuf<_Elem, _Tr>
	{
	typedef basic_streambuf<_Elem, _Tr> _Wide_streambuf;

	public:
	typedef typename _Codecvt::state_type state_type;

	/** Default constructor.
	*
	* @param __bytebuf The underlying byte stream buffer.
	* @param __pcvt The facet to use for conversions.
	* @param __state Initial conversion state.
	*
	* Takes ownership of @p __pcvt and will delete it in the destructor.
	*/
	explicit
	wbuffer_convert(streambuf* __bytebuf = 0, _Codecvt* __pcvt = new _Codecvt,
	state_type __state = state_type())
	: _M_buf(__bytebuf), _M_cvt(__pcvt), _M_state(__state)
	{
	if (!_M_cvt)
	__throw_logic_error("wbuffer_convert");

	_M_always_noconv = _M_cvt->always_noconv();

	if (_M_buf)
	{
	this->setp(_M_put_area, _M_put_area + _S_buffer_length);
	this->setg(_M_get_area + _S_putback_length,
	_M_get_area + _S_putback_length,
	_M_get_area + _S_putback_length);
	}
	}

	~wbuffer_convert() = default;

	// _GLIBCXX_RESOLVE_LIB_DEFECTS
	// 2176. Special members for wstring_convert and wbuffer_convert
	wbuffer_convert(const wbuffer_convert&) = delete;
	wbuffer_convert& operator=(const wbuffer_convert&) = delete;

	streambuf* rdbuf() const noexcept { return _M_buf; }

	streambuf*
	rdbuf(streambuf *__bytebuf) noexcept
	{
	auto __prev = _M_buf;
	_M_buf = __bytebuf;
	return __prev;
	}

	/// The conversion state following the last conversion.
	state_type state() const noexcept { return _M_state; }

	protected:
	int
	sync()
	{ return _M_buf && _M_conv_put() && _M_buf->pubsync() ? 0 : -1; }

	typename _Wide_streambuf::int_type
	overflow(typename _Wide_streambuf::int_type __out)
	{
	if (!_M_buf \|\| !_M_conv_put())
	return _Tr::eof();
	else if (!_Tr::eq_int_type(__out, _Tr::eof()))
	return this->sputc(__out);
	return _Tr::not_eof(__out);
	}

	typename _Wide_streambuf::int_type
	underflow()
	{
	if (!_M_buf)
	return _Tr::eof();

	if (this->gptr() < this->egptr() \|\| (_M_buf && _M_conv_get()))
	return _Tr::to_int_type(*this->gptr());
	else
	return _Tr::eof();
	}

	streamsize
	xsputn(const typename _Wide_streambuf::char_type* __s, streamsize __n)
	{
	if (!_M_buf \|\| __n == 0)
	return 0;
	streamsize __done = 0;
	do
	{
	auto __nn = std::min<streamsize>(this->epptr() - this->pptr(),
	__n - __done);
	_Tr::copy(this->pptr(), __s + __done, __nn);
	this->pbump(__nn);
	__done += __nn;
	} while (__done < __n && _M_conv_put());
	return __done;
	}

	private:
	// fill the get area from converted contents of the byte stream buffer
	bool
	_M_conv_get()
	{
	const streamsize __pb1 = this->gptr() - this->eback();
	const streamsize __pb2 = _S_putback_length;
	const streamsize __npb = std::min(__pb1, __pb2);

	_Tr::move(_M_get_area + _S_putback_length - __npb,
	this->gptr() - __npb, __npb);

	streamsize __nbytes = sizeof(_M_get_buf) - _M_unconv;
	__nbytes = std::min(__nbytes, _M_buf->in_avail());
	if (__nbytes < 1)
	__nbytes == 1;
	__nbytes = _M_buf->sgetn(_M_get_buf + _M_unconv, __nbytes);
	if (__nbytes < 1)
	return false;
	__nbytes += _M_unconv;

	// convert _M_get_buf into _M_get_area

	_Elem* __outbuf = _M_get_area + _S_putback_length;
	_Elem* __outnext = __outbuf;
	const char* __bnext = _M_get_buf;

	codecvt_base::result __result;
	if (_M_always_noconv)
	__result = codecvt_base::noconv;
	else
	{
	_Elem* __outend = _M_get_area + _S_buffer_length;

	__result = _M_cvt->in(_M_state,
	__bnext, __bnext + __nbytes, __bnext,
	__outbuf, __outend, __outnext);
	}

	if (__result == codecvt_base::noconv)
	{
	// cast is safe because noconv means _Elem is same type as char
	auto __get_buf = reinterpret_cast<const _Elem*>(_M_get_buf);
	_Tr::copy(__outbuf, __get_buf, __nbytes);
	_M_unconv = 0;
	return true;
	}

	if ((_M_unconv = _M_get_buf + __nbytes - __bnext))
	char_traits<char>::move(_M_get_buf, __bnext, _M_unconv);

	this->setg(__outbuf, __outbuf, __outnext);

	return __result != codecvt_base::error;
	}

	// unused
	bool
	_M_put(...)
	{ return false; }

	bool
	_M_put(const char* __p, streamsize __n)
	{
	if (_M_buf->sputn(__p, __n) < __n)
	return false;
	}

	// convert the put area and write to the byte stream buffer
	bool
	_M_conv_put()
	{
	_Elem* const __first = this->pbase();
	const _Elem* const __last = this->pptr();
	const streamsize __pending = __last - __first;

	if (_M_always_noconv)
	return _M_put(__first, __pending);

	char __outbuf[2 * _S_buffer_length];

	const _Elem* __next = __first;
	const _Elem* __start;
	do
	{
	__start = __next;
	char* __outnext = __outbuf;
	char* const __outlast = __outbuf + sizeof(__outbuf);
	auto __result = _M_cvt->out(_M_state, __next, __last, __next,
	__outnext, __outlast, __outnext);
	if (__result == codecvt_base::error)
	return false;
	else if (__result == codecvt_base::noconv)
	return _M_put(__next, __pending);

	if (!_M_put(__outbuf, __outnext - __outbuf))
	return false;
	}
	while (__next != __last && __next != __start);

	if (__next != __last)
	_Tr::move(__first, __next, __last - __next);

	this->pbump(__first - __next);
	return __next != __first;
	}

	streambuf* _M_buf;
	unique_ptr<_Codecvt> _M_cvt;
	state_type _M_state;

	static const streamsize _S_buffer_length = 32;
	static const streamsize _S_putback_length = 3;
	_Elem _M_put_area[_S_buffer_length];
	_Elem _M_get_area[_S_buffer_length];
	streamsize _M_unconv = 0;
	char _M_get_buf[_S_buffer_length-_S_putback_length];
	bool _M_always_noconv;
	};

	#endif // _GLIBCXX_USE_WCHAR_T

	/// @} group locales

	_GLIBCXX_END_NAMESPACE_VERSION
	} // namespace

	#endif // __cplusplus

	#endif /* _LOCALE_CONV_H */