// Locale support -*- C++ -*-

// Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006
// 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 2, 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.

// You should have received a copy of the GNU General Public License along
// with this library; see the file COPYING.  If not, write to the Free
// Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
// USA.

// As a special exception, you may use this file as part of a free software
// library without restriction.  Specifically, if other files instantiate
// templates or use macros or inline functions from this file, or you compile
// this file and link it with other files to produce an executable, this
// file does not by itself cause the resulting executable to be covered by
// the GNU General Public License.  This exception does not however
// invalidate any other reasons why the executable file might be covered by
// the GNU General Public License.

/** @file locale_facets.h
 *  This is an internal header file, included by other library headers.
 *  You should not attempt to use it directly.
 */

//
// ISO C++ 14882: 22.1  Locales
//

#ifndef _LOCALE_FACETS_H
#define _LOCALE_FACETS_H 1

#pragma GCC system_header

#include <ctime>	// For struct tm
#include <cwctype>	// For wctype_t
#include <bits/ctype_base.h>	
#include <iosfwd>
#include <bits/ios_base.h>  // For ios_base, ios_base::iostate
#include <streambuf>
#include <bits/cpp_type_traits.h>

_GLIBCXX_BEGIN_NAMESPACE(std)

  // NB: Don't instantiate required wchar_t facets if no wchar_t support.
#ifdef _GLIBCXX_USE_WCHAR_T
# define  _GLIBCXX_NUM_FACETS 28
#else
# define  _GLIBCXX_NUM_FACETS 14
#endif

  // Convert string to numeric value of type _Tv and store results.
  // NB: This is specialized for all required types, there is no
  // generic definition.
  template<typename _Tv>
    void
    __convert_to_v(const char* __in, _Tv& __out, ios_base::iostate& __err,
		   const __c_locale& __cloc);

  // Explicit specializations for required types.
  template<>
    void
    __convert_to_v(const char*, float&, ios_base::iostate&,
		   const __c_locale&);

  template<>
    void
    __convert_to_v(const char*, double&, ios_base::iostate&,
		   const __c_locale&);

  template<>
    void
    __convert_to_v(const char*, long double&, ios_base::iostate&,
		   const __c_locale&);

  // NB: __pad is a struct, rather than a function, so it can be
  // partially-specialized.
  template<typename _CharT, typename _Traits>
    struct __pad
    {
      static void
      _S_pad(ios_base& __io, _CharT __fill, _CharT* __news,
	     const _CharT* __olds, const streamsize __newlen,
	     const streamsize __oldlen, const bool __num);
    };

  // Used by both numeric and monetary facets.
  // Inserts "group separator" characters into an array of characters.
  // It's recursive, one iteration per group.  It moves the characters
  // in the buffer this way: "xxxx12345" -> "12,345xxx".  Call this
  // only with __glen != 0.
  template<typename _CharT>
    _CharT*
    __add_grouping(_CharT* __s, _CharT __sep,
		   const char* __gbeg, size_t __gsize,
		   const _CharT* __first, const _CharT* __last);

  // This template permits specializing facet output code for
  // ostreambuf_iterator.  For ostreambuf_iterator, sputn is
  // significantly more efficient than incrementing iterators.
  template<typename _CharT>
    inline
    ostreambuf_iterator<_CharT>
    __write(ostreambuf_iterator<_CharT> __s, const _CharT* __ws, int __len)
    {
      __s._M_put(__ws, __len);
      return __s;
    }

  // This is the unspecialized form of the template.
  template<typename _CharT, typename _OutIter>
    inline
    _OutIter
    __write(_OutIter __s, const _CharT* __ws, int __len)
    {
      for (int __j = 0; __j < __len; __j++, ++__s)
	*__s = __ws[__j];
      return __s;
    }


  // 22.2.1.1  Template class ctype
  // Include host and configuration specific ctype enums for ctype_base.

  // Common base for ctype<_CharT>.
  /**
   *  @brief  Common base for ctype facet
   *
   *  This template class provides implementations of the public functions
   *  that forward to the protected virtual functions.
   *
   *  This template also provides abtract stubs for the protected virtual
   *  functions.
  */
  template<typename _CharT>
    class __ctype_abstract_base : public locale::facet, public ctype_base
    {
    public:
      // Types:
      /// Typedef for the template parameter
      typedef _CharT char_type;

      /**
       *  @brief  Test char_type classification.
       *
       *  This function finds a mask M for @a c and compares it to mask @a m.
       *  It does so by returning the value of ctype<char_type>::do_is().
       *
       *  @param c  The char_type to compare the mask of.
       *  @param m  The mask to compare against.
       *  @return  (M & m) != 0.
      */
      bool
      is(mask __m, char_type __c) const
      { return this->do_is(__m, __c); }

      /**
       *  @brief  Return a mask array.
       *
       *  This function finds the mask for each char_type in the range [lo,hi)
       *  and successively writes it to vec.  vec must have as many elements
       *  as the char array.  It does so by returning the value of
       *  ctype<char_type>::do_is().
       *
       *  @param lo  Pointer to start of range.
       *  @param hi  Pointer to end of range.
       *  @param vec  Pointer to an array of mask storage.
       *  @return  @a hi.
      */
      const char_type*
      is(const char_type *__lo, const char_type *__hi, mask *__vec) const
      { return this->do_is(__lo, __hi, __vec); }

      /**
       *  @brief  Find char_type matching a mask
       *
       *  This function searches for and returns the first char_type c in
       *  [lo,hi) for which is(m,c) is true.  It does so by returning
       *  ctype<char_type>::do_scan_is().
       *
       *  @param m  The mask to compare against.
       *  @param lo  Pointer to start of range.
       *  @param hi  Pointer to end of range.
       *  @return  Pointer to matching char_type if found, else @a hi.
      */
      const char_type*
      scan_is(mask __m, const char_type* __lo, const char_type* __hi) const
      { return this->do_scan_is(__m, __lo, __hi); }

      /**
       *  @brief  Find char_type not matching a mask
       *
       *  This function searches for and returns the first char_type c in
       *  [lo,hi) for which is(m,c) is false.  It does so by returning
       *  ctype<char_type>::do_scan_not().
       *
       *  @param m  The mask to compare against.
       *  @param lo  Pointer to first char in range.
       *  @param hi  Pointer to end of range.
       *  @return  Pointer to non-matching char if found, else @a hi.
      */
      const char_type*
      scan_not(mask __m, const char_type* __lo, const char_type* __hi) const
      { return this->do_scan_not(__m, __lo, __hi); }

      /**
       *  @brief  Convert to uppercase.
       *
       *  This function converts the argument to uppercase if possible.
       *  If not possible (for example, '2'), returns the argument.  It does
       *  so by returning ctype<char_type>::do_toupper().
       *
       *  @param c  The char_type to convert.
       *  @return  The uppercase char_type if convertible, else @a c.
      */
      char_type
      toupper(char_type __c) const
      { return this->do_toupper(__c); }

      /**
       *  @brief  Convert array to uppercase.
       *
       *  This function converts each char_type in the range [lo,hi) to
       *  uppercase if possible.  Other elements remain untouched.  It does so
       *  by returning ctype<char_type>:: do_toupper(lo, hi).
       *
       *  @param lo  Pointer to start of range.
       *  @param hi  Pointer to end of range.
       *  @return  @a hi.
      */
      const char_type*
      toupper(char_type *__lo, const char_type* __hi) const
      { return this->do_toupper(__lo, __hi); }

      /**
       *  @brief  Convert to lowercase.
       *
       *  This function converts the argument to lowercase if possible.  If
       *  not possible (for example, '2'), returns the argument.  It does so
       *  by returning ctype<char_type>::do_tolower(c).
       *
       *  @param c  The char_type to convert.
       *  @return  The lowercase char_type if convertible, else @a c.
      */
      char_type
      tolower(char_type __c) const
      { return this->do_tolower(__c); }

      /**
       *  @brief  Convert array to lowercase.
       *
       *  This function converts each char_type in the range [lo,hi) to
       *  lowercase if possible.  Other elements remain untouched.  It does so
       *  by returning ctype<char_type>:: do_tolower(lo, hi).
       *
       *  @param lo  Pointer to start of range.
       *  @param hi  Pointer to end of range.
       *  @return  @a hi.
      */
      const char_type*
      tolower(char_type* __lo, const char_type* __hi) const
      { return this->do_tolower(__lo, __hi); }

      /**
       *  @brief  Widen char to char_type
       *
       *  This function converts the char argument to char_type using the
       *  simplest reasonable transformation.  It does so by returning
       *  ctype<char_type>::do_widen(c).
       *
       *  Note: this is not what you want for codepage conversions.  See
       *  codecvt for that.
       *
       *  @param c  The char to convert.
       *  @return  The converted char_type.
      */
      char_type
      widen(char __c) const
      { return this->do_widen(__c); }

      /**
       *  @brief  Widen array to char_type
       *
       *  This function converts each char in the input to char_type using the
       *  simplest reasonable transformation.  It does so by returning
       *  ctype<char_type>::do_widen(c).
       *
       *  Note: this is not what you want for codepage conversions.  See
       *  codecvt for that.
       *
       *  @param lo  Pointer to start of range.
       *  @param hi  Pointer to end of range.
       *  @param to  Pointer to the destination array.
       *  @return  @a hi.
      */
      const char*
      widen(const char* __lo, const char* __hi, char_type* __to) const
      { return this->do_widen(__lo, __hi, __to); }

      /**
       *  @brief  Narrow char_type to char
       *
       *  This function converts the char_type to char using the simplest
       *  reasonable transformation.  If the conversion fails, dfault is
       *  returned instead.  It does so by returning
       *  ctype<char_type>::do_narrow(c).
       *
       *  Note: this is not what you want for codepage conversions.  See
       *  codecvt for that.
       *
       *  @param c  The char_type to convert.
       *  @param dfault  Char to return if conversion fails.
       *  @return  The converted char.
      */
      char
      narrow(char_type __c, char __dfault) const
      { return this->do_narrow(__c, __dfault); }

      /**
       *  @brief  Narrow array to char array
       *
       *  This function converts each char_type in the input to char using the
       *  simplest reasonable transformation and writes the results to the
       *  destination array.  For any char_type in the input that cannot be
       *  converted, @a dfault is used instead.  It does so by returning
       *  ctype<char_type>::do_narrow(lo, hi, dfault, to).
       *
       *  Note: this is not what you want for codepage conversions.  See
       *  codecvt for that.
       *
       *  @param lo  Pointer to start of range.
       *  @param hi  Pointer to end of range.
       *  @param dfault  Char to use if conversion fails.
       *  @param to  Pointer to the destination array.
       *  @return  @a hi.
      */
      const char_type*
      narrow(const char_type* __lo, const char_type* __hi,
	      char __dfault, char *__to) const
      { return this->do_narrow(__lo, __hi, __dfault, __to); }

    protected:
      explicit
      __ctype_abstract_base(size_t __refs = 0): facet(__refs) { }

      virtual
      ~__ctype_abstract_base() { }

      /**
       *  @brief  Test char_type classification.
       *
       *  This function finds a mask M for @a c and compares it to mask @a m.
       *
       *  do_is() is a hook for a derived facet to change the behavior of
       *  classifying.  do_is() must always return the same result for the
       *  same input.
       *
       *  @param c  The char_type to find the mask of.
       *  @param m  The mask to compare against.
       *  @return  (M & m) != 0.
      */
      virtual bool
      do_is(mask __m, char_type __c) const = 0;

      /**
       *  @brief  Return a mask array.
       *
       *  This function finds the mask for each char_type in the range [lo,hi)
       *  and successively writes it to vec.  vec must have as many elements
       *  as the input.
       *
       *  do_is() is a hook for a derived facet to change the behavior of
       *  classifying.  do_is() must always return the same result for the
       *  same input.
       *
       *  @param lo  Pointer to start of range.
       *  @param hi  Pointer to end of range.
       *  @param vec  Pointer to an array of mask storage.
       *  @return  @a hi.
      */
      virtual const char_type*
      do_is(const char_type* __lo, const char_type* __hi,
	    mask* __vec) const = 0;

      /**
       *  @brief  Find char_type matching mask
       *
       *  This function searches for and returns the first char_type c in
       *  [lo,hi) for which is(m,c) is true.
       *
       *  do_scan_is() is a hook for a derived facet to change the behavior of
       *  match searching.  do_is() must always return the same result for the
       *  same input.
       *
       *  @param m  The mask to compare against.
       *  @param lo  Pointer to start of range.
       *  @param hi  Pointer to end of range.
       *  @return  Pointer to a matching char_type if found, else @a hi.
      */
      virtual const char_type*
      do_scan_is(mask __m, const char_type* __lo,
		 const char_type* __hi) const = 0;

      /**
       *  @brief  Find char_type not matching mask
       *
       *  This function searches for and returns a pointer to the first
       *  char_type c of [lo,hi) for which is(m,c) is false.
       *
       *  do_scan_is() is a hook for a derived facet to change the behavior of
       *  match searching.  do_is() must always return the same result for the
       *  same input.
       *
       *  @param m  The mask to compare against.
       *  @param lo  Pointer to start of range.
       *  @param hi  Pointer to end of range.
       *  @return  Pointer to a non-matching char_type if found, else @a hi.
      */
      virtual const char_type*
      do_scan_not(mask __m, const char_type* __lo,
		  const char_type* __hi) const = 0;

      /**
       *  @brief  Convert to uppercase.
       *
       *  This virtual function converts the char_type argument to uppercase
       *  if possible.  If not possible (for example, '2'), returns the
       *  argument.
       *
       *  do_toupper() is a hook for a derived facet to change the behavior of
       *  uppercasing.  do_toupper() must always return the same result for
       *  the same input.
       *
       *  @param c  The char_type to convert.
       *  @return  The uppercase char_type if convertible, else @a c.
      */
      virtual char_type
      do_toupper(char_type) const = 0;

      /**
       *  @brief  Convert array to uppercase.
       *
       *  This virtual function converts each char_type in the range [lo,hi)
       *  to uppercase if possible.  Other elements remain untouched.
       *
       *  do_toupper() is a hook for a derived facet to change the behavior of
       *  uppercasing.  do_toupper() must always return the same result for
       *  the same input.
       *
       *  @param lo  Pointer to start of range.
       *  @param hi  Pointer to end of range.
       *  @return  @a hi.
      */
      virtual const char_type*
      do_toupper(char_type* __lo, const char_type* __hi) const = 0;

      /**
       *  @brief  Convert to lowercase.
       *
       *  This virtual function converts the argument to lowercase if
       *  possible.  If not possible (for example, '2'), returns the argument.
       *
       *  do_tolower() is a hook for a derived facet to change the behavior of
       *  lowercasing.  do_tolower() must always return the same result for
       *  the same input.
       *
       *  @param c  The char_type to convert.
       *  @return  The lowercase char_type if convertible, else @a c.
      */
      virtual char_type
      do_tolower(char_type) const = 0;

      /**
       *  @brief  Convert array to lowercase.
       *
       *  This virtual function converts each char_type in the range [lo,hi)
       *  to lowercase if possible.  Other elements remain untouched.
       *
       *  do_tolower() is a hook for a derived facet to change the behavior of
       *  lowercasing.  do_tolower() must always return the same result for
       *  the same input.
       *
       *  @param lo  Pointer to start of range.
       *  @param hi  Pointer to end of range.
       *  @return  @a hi.
      */
      virtual const char_type*
      do_tolower(char_type* __lo, const char_type* __hi) const = 0;

      /**
       *  @brief  Widen char
       *
       *  This virtual function converts the char to char_type using the
       *  simplest reasonable transformation.
       *
       *  do_widen() is a hook for a derived facet to change the behavior of
       *  widening.  do_widen() must always return the same result for the
       *  same input.
       *
       *  Note: this is not what you want for codepage conversions.  See
       *  codecvt for that.
       *
       *  @param c  The char to convert.
       *  @return  The converted char_type
      */
      virtual char_type
      do_widen(char) const = 0;

      /**
       *  @brief  Widen char array
       *
       *  This function converts each char in the input to char_type using the
       *  simplest reasonable transformation.
       *
       *  do_widen() is a hook for a derived facet to change the behavior of
       *  widening.  do_widen() must always return the same result for the
       *  same input.
       *
       *  Note: this is not what you want for codepage conversions.  See
       *  codecvt for that.
       *
       *  @param lo  Pointer to start range.
       *  @param hi  Pointer to end of range.
       *  @param to  Pointer to the destination array.
       *  @return  @a hi.
      */
      virtual const char*
      do_widen(const char* __lo, const char* __hi,
	       char_type* __dest) const = 0;

      /**
       *  @brief  Narrow char_type to char
       *
       *  This virtual function converts the argument to char using the
       *  simplest reasonable transformation.  If the conversion fails, dfault
       *  is returned instead.
       *
       *  do_narrow() is a hook for a derived facet to change the behavior of
       *  narrowing.  do_narrow() must always return the same result for the
       *  same input.
       *
       *  Note: this is not what you want for codepage conversions.  See
       *  codecvt for that.
       *
       *  @param c  The char_type to convert.
       *  @param dfault  Char to return if conversion fails.
       *  @return  The converted char.
      */
      virtual char
      do_narrow(char_type, char __dfault) const = 0;

      /**
       *  @brief  Narrow char_type array to char
       *
       *  This virtual function converts each char_type in the range [lo,hi) to
       *  char using the simplest reasonable transformation and writes the
       *  results to the destination array.  For any element in the input that
       *  cannot be converted, @a dfault is used instead.
       *
       *  do_narrow() is a hook for a derived facet to change the behavior of
       *  narrowing.  do_narrow() must always return the same result for the
       *  same input.
       *
       *  Note: this is not what you want for codepage conversions.  See
       *  codecvt for that.
       *
       *  @param lo  Pointer to start of range.
       *  @param hi  Pointer to end of range.
       *  @param dfault  Char to use if conversion fails.
       *  @param to  Pointer to the destination array.
       *  @return  @a hi.
      */
      virtual const char_type*
      do_narrow(const char_type* __lo, const char_type* __hi,
		char __dfault, char* __dest) const = 0;
    };

  // NB: Generic, mostly useless implementation.
  /**
   *  @brief  Template ctype facet
   *
   *  This template class defines classification and conversion functions for
   *  character sets.  It wraps <cctype> functionality.  Ctype gets used by
   *  streams for many I/O operations.
   *
   *  This template provides the protected virtual functions the developer
   *  will have to replace in a derived class or specialization to make a
   *  working facet.  The public functions that access them are defined in
   *  __ctype_abstract_base, to allow for implementation flexibility.  See
   *  ctype<wchar_t> for an example.  The functions are documented in
   *  __ctype_abstract_base.
   *
   *  Note: implementations are provided for all the protected virtual
   *  functions, but will likely not be useful.
  */
  template<typename _CharT>
    class ctype : public __ctype_abstract_base<_CharT>
    {
    public:
      // Types:
      typedef _CharT			char_type;
      typedef typename __ctype_abstract_base<_CharT>::mask mask;

      /// The facet id for ctype<char_type>
      static locale::id			id;

      explicit
      ctype(size_t __refs = 0) : __ctype_abstract_base<_CharT>(__refs) { }

   protected:
      virtual
      ~ctype();

      virtual bool
      do_is(mask __m, char_type __c) const;

      virtual const char_type*
      do_is(const char_type* __lo, const char_type* __hi, mask* __vec) const;

      virtual const char_type*
      do_scan_is(mask __m, const char_type* __lo, const char_type* __hi) const;

      virtual const char_type*
      do_scan_not(mask __m, const char_type* __lo,
		  const char_type* __hi) const;

      virtual char_type
      do_toupper(char_type __c) const;

      virtual const char_type*
      do_toupper(char_type* __lo, const char_type* __hi) const;

      virtual char_type
      do_tolower(char_type __c) const;

      virtual const char_type*
      do_tolower(char_type* __lo, const char_type* __hi) const;

      virtual char_type
      do_widen(char __c) const;

      virtual const char*
      do_widen(const char* __lo, const char* __hi, char_type* __dest) const;

      virtual char
      do_narrow(char_type, char __dfault) const;

      virtual const char_type*
      do_narrow(const char_type* __lo, const char_type* __hi,
		char __dfault, char* __dest) const;
    };

  template<typename _CharT>
    locale::id ctype<_CharT>::id;

  // 22.2.1.3  ctype<char> specialization.
  /**
   *  @brief  The ctype<char> specialization.
   *
   *  This class defines classification and conversion functions for
   *  the char type.  It gets used by char streams for many I/O
   *  operations.  The char specialization provides a number of
   *  optimizations as well.
  */
  template<>
    class ctype<char> : public locale::facet, public ctype_base
    {
    public:
      // Types:
      /// Typedef for the template parameter char.
      typedef char		char_type;

    protected:
      // Data Members:
      __c_locale		_M_c_locale_ctype;
      bool			_M_del;
      __to_type			_M_toupper;
      __to_type			_M_tolower;
      const mask*		_M_table;
      mutable char		_M_widen_ok;
      mutable char		_M_widen[1 + static_cast<unsigned char>(-1)];
      mutable char		_M_narrow[1 + static_cast<unsigned char>(-1)];
      mutable char		_M_narrow_ok;	// 0 uninitialized, 1 init,
						// 2 memcpy can't be used

    public:
      /// The facet id for ctype<char>
      static locale::id        id;
      /// The size of the mask table.  It is SCHAR_MAX + 1.
      static const size_t      table_size = 1 + static_cast<unsigned char>(-1);

      /**
       *  @brief  Constructor performs initialization.
       *
       *  This is the constructor provided by the standard.
       *
       *  @param table If non-zero, table is used as the per-char mask.
       *               Else classic_table() is used.
       *  @param del   If true, passes ownership of table to this facet.
       *  @param refs  Passed to the base facet class.
      */
      explicit
      ctype(const mask* __table = 0, bool __del = false, size_t __refs = 0);

      /**
       *  @brief  Constructor performs static initialization.
       *
       *  This constructor is used to construct the initial C locale facet.
       *
       *  @param cloc  Handle to C locale data.
       *  @param table If non-zero, table is used as the per-char mask.
       *  @param del   If true, passes ownership of table to this facet.
       *  @param refs  Passed to the base facet class.
      */
      explicit
      ctype(__c_locale __cloc, const mask* __table = 0, bool __del = false,
	    size_t __refs = 0);

      /**
       *  @brief  Test char classification.
       *
       *  This function compares the mask table[c] to @a m.
       *
       *  @param c  The char to compare the mask of.
       *  @param m  The mask to compare against.
       *  @return  True if m & table[c] is true, false otherwise.
      */
      inline bool
      is(mask __m, char __c) const;

      /**
       *  @brief  Return a mask array.
       *
       *  This function finds the mask for each char in the range [lo, hi) and
       *  successively writes it to vec.  vec must have as many elements as
       *  the char array.
       *
       *  @param lo  Pointer to start of range.
       *  @param hi  Pointer to end of range.
       *  @param vec  Pointer to an array of mask storage.
       *  @return  @a hi.
      */
      inline const char*
      is(const char* __lo, const char* __hi, mask* __vec) const;

      /**
       *  @brief  Find char matching a mask
       *
       *  This function searches for and returns the first char in [lo,hi) for
       *  which is(m,char) is true.
       *
       *  @param m  The mask to compare against.
       *  @param lo  Pointer to start of range.
       *  @param hi  Pointer to end of range.
       *  @return  Pointer to a matching char if found, else @a hi.
      */
      inline const char*
      scan_is(mask __m, const char* __lo, const char* __hi) const;

      /**
       *  @brief  Find char not matching a mask
       *
       *  This function searches for and returns a pointer to the first char
       *  in [lo,hi) for which is(m,char) is false.
       *
       *  @param m  The mask to compare against.
       *  @param lo  Pointer to start of range.
       *  @param hi  Pointer to end of range.
       *  @return  Pointer to a non-matching char if found, else @a hi.
      */
      inline const char*
      scan_not(mask __m, const char* __lo, const char* __hi) const;

      /**
       *  @brief  Convert to uppercase.
       *
       *  This function converts the char argument to uppercase if possible.
       *  If not possible (for example, '2'), returns the argument.
       *
       *  toupper() acts as if it returns ctype<char>::do_toupper(c).
       *  do_toupper() must always return the same result for the same input.
       *
       *  @param c  The char to convert.
       *  @return  The uppercase char if convertible, else @a c.
      */
      char_type
      toupper(char_type __c) const
      { return this->do_toupper(__c); }

      /**
       *  @brief  Convert array to uppercase.
       *
       *  This function converts each char in the range [lo,hi) to uppercase
       *  if possible.  Other chars remain untouched.
       *
       *  toupper() acts as if it returns ctype<char>:: do_toupper(lo, hi).
       *  do_toupper() must always return the same result for the same input.
       *
       *  @param lo  Pointer to first char in range.
       *  @param hi  Pointer to end of range.
       *  @return  @a hi.
      */
      const char_type*
      toupper(char_type *__lo, const char_type* __hi) const
      { return this->do_toupper(__lo, __hi); }

      /**
       *  @brief  Convert to lowercase.
       *
       *  This function converts the char argument to lowercase if possible.
       *  If not possible (for example, '2'), returns the argument.
       *
       *  tolower() acts as if it returns ctype<char>::do_tolower(c).
       *  do_tolower() must always return the same result for the same input.
       *
       *  @param c  The char to convert.
       *  @return  The lowercase char if convertible, else @a c.
      */
      char_type
      tolower(char_type __c) const
      { return this->do_tolower(__c); }

      /**
       *  @brief  Convert array to lowercase.
       *
       *  This function converts each char in the range [lo,hi) to lowercase
       *  if possible.  Other chars remain untouched.
       *
       *  tolower() acts as if it returns ctype<char>:: do_tolower(lo, hi).
       *  do_tolower() must always return the same result for the same input.
       *
       *  @param lo  Pointer to first char in range.
       *  @param hi  Pointer to end of range.
       *  @return  @a hi.
      */
      const char_type*
      tolower(char_type* __lo, const char_type* __hi) const
      { return this->do_tolower(__lo, __hi); }

      /**
       *  @brief  Widen char
       *
       *  This function converts the char to char_type using the simplest
       *  reasonable transformation.  For an underived ctype<char> facet, the
       *  argument will be returned unchanged.
       *
       *  This function works as if it returns ctype<char>::do_widen(c).
       *  do_widen() must always return the same result for the same input.
       *
       *  Note: this is not what you want for codepage conversions.  See
       *  codecvt for that.
       *
       *  @param c  The char to convert.
       *  @return  The converted character.
      */
      char_type
      widen(char __c) const
      {
	if (_M_widen_ok)
	  return _M_widen[static_cast<unsigned char>(__c)];
	this->_M_widen_init();
	return this->do_widen(__c);
      }

      /**
       *  @brief  Widen char array
       *
       *  This function converts each char in the input to char using the
       *  simplest reasonable transformation.  For an underived ctype<char>
       *  facet, the argument will be copied unchanged.
       *
       *  This function works as if it returns ctype<char>::do_widen(c).
       *  do_widen() must always return the same result for the same input.
       *
       *  Note: this is not what you want for codepage conversions.  See
       *  codecvt for that.
       *
       *  @param lo  Pointer to first char in range.
       *  @param hi  Pointer to end of range.
       *  @param to  Pointer to the destination array.
       *  @return  @a hi.
      */
      const char*
      widen(const char* __lo, const char* __hi, char_type* __to) const
      {
	if (_M_widen_ok == 1)
	  {
	    memcpy(__to, __lo, __hi - __lo);
	    return __hi;
	  }
	if (!_M_widen_ok)
	  _M_widen_init();
	return this->do_widen(__lo, __hi, __to);
      }

      /**
       *  @brief  Narrow char
       *
       *  This function converts the char to char using the simplest
       *  reasonable transformation.  If the conversion fails, dfault is
       *  returned instead.  For an underived ctype<char> facet, @a c
       *  will be returned unchanged.
       *
       *  This function works as if it returns ctype<char>::do_narrow(c).
       *  do_narrow() must always return the same result for the same input.
       *
       *  Note: this is not what you want for codepage conversions.  See
       *  codecvt for that.
       *
       *  @param c  The char to convert.
       *  @param dfault  Char to return if conversion fails.
       *  @return  The converted character.
      */
      char
      narrow(char_type __c, char __dfault) const
      {
	if (_M_narrow[static_cast<unsigned char>(__c)])
	  return _M_narrow[static_cast<unsigned char>(__c)];
	const char __t = do_narrow(__c, __dfault);
	if (__t != __dfault)
	  _M_narrow[static_cast<unsigned char>(__c)] = __t;
	return __t;
      }

      /**
       *  @brief  Narrow char array
       *
       *  This function converts each char in the input to char using the
       *  simplest reasonable transformation and writes the results to the
       *  destination array.  For any char in the input that cannot be
       *  converted, @a dfault is used instead.  For an underived ctype<char>
       *  facet, the argument will be copied unchanged.
       *
       *  This function works as if it returns ctype<char>::do_narrow(lo, hi,
       *  dfault, to).  do_narrow() must always return the same result for the
       *  same input.
       *
       *  Note: this is not what you want for codepage conversions.  See
       *  codecvt for that.
       *
       *  @param lo  Pointer to start of range.
       *  @param hi  Pointer to end of range.
       *  @param dfault  Char to use if conversion fails.
       *  @param to  Pointer to the destination array.
       *  @return  @a hi.
      */
      const char_type*
      narrow(const char_type* __lo, const char_type* __hi,
	     char __dfault, char *__to) const
      {
	if (__builtin_expect(_M_narrow_ok == 1, true))
	  {
	    memcpy(__to, __lo, __hi - __lo);
	    return __hi;
	  }
	if (!_M_narrow_ok)
	  _M_narrow_init();
	return this->do_narrow(__lo, __hi, __dfault, __to);
      }

    protected:
      /// Returns a pointer to the mask table provided to the constructor, or
      /// the default from classic_table() if none was provided.
      const mask*
      table() const throw()
      { return _M_table; }

      /// Returns a pointer to the C locale mask table.
      static const mask*
      classic_table() throw();

      /**
       *  @brief  Destructor.
       *
       *  This function deletes table() if @a del was true in the
       *  constructor.
      */
      virtual
      ~ctype();

      /**
       *  @brief  Convert to uppercase.
       *
       *  This virtual function converts the char argument to uppercase if
       *  possible.  If not possible (for example, '2'), returns the argument.
       *
       *  do_toupper() is a hook for a derived facet to change the behavior of
       *  uppercasing.  do_toupper() must always return the same result for
       *  the same input.
       *
       *  @param c  The char to convert.
       *  @return  The uppercase char if convertible, else @a c.
      */
      virtual char_type
      do_toupper(char_type) const;

      /**
       *  @brief  Convert array to uppercase.
       *
       *  This virtual function converts each char in the range [lo,hi) to
       *  uppercase if possible.  Other chars remain untouched.
       *
       *  do_toupper() is a hook for a derived facet to change the behavior of
       *  uppercasing.  do_toupper() must always return the same result for
       *  the same input.
       *
       *  @param lo  Pointer to start of range.
       *  @param hi  Pointer to end of range.
       *  @return  @a hi.
      */
      virtual const char_type*
      do_toupper(char_type* __lo, const char_type* __hi) const;

      /**
       *  @brief  Convert to lowercase.
       *
       *  This virtual function converts the char argument to lowercase if
       *  possible.  If not possible (for example, '2'), returns the argument.
       *
       *  do_tolower() is a hook for a derived facet to change the behavior of
       *  lowercasing.  do_tolower() must always return the same result for
       *  the same input.
       *
       *  @param c  The char to convert.
       *  @return  The lowercase char if convertible, else @a c.
      */
      virtual char_type
      do_tolower(char_type) const;

      /**
       *  @brief  Convert array to lowercase.
       *
       *  This virtual function converts each char in the range [lo,hi) to
       *  lowercase if possible.  Other chars remain untouched.
       *
       *  do_tolower() is a hook for a derived facet to change the behavior of
       *  lowercasing.  do_tolower() must always return the same result for
       *  the same input.
       *
       *  @param lo  Pointer to first char in range.
       *  @param hi  Pointer to end of range.
       *  @return  @a hi.
      */
      virtual const char_type*
      do_tolower(char_type* __lo, const char_type* __hi) const;

      /**
       *  @brief  Widen char
       *
       *  This virtual function converts the char to char using the simplest
       *  reasonable transformation.  For an underived ctype<char> facet, the
       *  argument will be returned unchanged.
       *
       *  do_widen() is a hook for a derived facet to change the behavior of
       *  widening.  do_widen() must always return the same result for the
       *  same input.
       *
       *  Note: this is not what you want for codepage conversions.  See
       *  codecvt for that.
       *
       *  @param c  The char to convert.
       *  @return  The converted character.
      */
      virtual char_type
      do_widen(char __c) const
      { return __c; }

      /**
       *  @brief  Widen char array
       *
       *  This function converts each char in the range [lo,hi) to char using
       *  the simplest reasonable transformation.  For an underived
       *  ctype<char> facet, the argument will be copied unchanged.
       *
       *  do_widen() is a hook for a derived facet to change the behavior of
       *  widening.  do_widen() must always return the same result for the
       *  same input.
       *
       *  Note: this is not what you want for codepage conversions.  See
       *  codecvt for that.
       *
       *  @param lo  Pointer to start of range.
       *  @param hi  Pointer to end of range.
       *  @param to  Pointer to the destination array.
       *  @return  @a hi.
      */
      virtual const char*
      do_widen(const char* __lo, const char* __hi, char_type* __dest) const
      {
	memcpy(__dest, __lo, __hi - __lo);
	return __hi;
      }

      /**
       *  @brief  Narrow char
       *
       *  This virtual function converts the char to char using the simplest
       *  reasonable transformation.  If the conversion fails, dfault is
       *  returned instead.  For an underived ctype<char> facet, @a c will be
       *  returned unchanged.
       *
       *  do_narrow() is a hook for a derived facet to change the behavior of
       *  narrowing.  do_narrow() must always return the same result for the
       *  same input.
       *
       *  Note: this is not what you want for codepage conversions.  See
       *  codecvt for that.
       *
       *  @param c  The char to convert.
       *  @param dfault  Char to return if conversion fails.
       *  @return  The converted char.
      */
      virtual char
      do_narrow(char_type __c, char) const
      { return __c; }

      /**
       *  @brief  Narrow char array to char array
       *
       *  This virtual function converts each char in the range [lo,hi) to
       *  char using the simplest reasonable transformation and writes the
       *  results to the destination array.  For any char in the input that
       *  cannot be converted, @a dfault is used instead.  For an underived
       *  ctype<char> facet, the argument will be copied unchanged.
       *
       *  do_narrow() is a hook for a derived facet to change the behavior of
       *  narrowing.  do_narrow() must always return the same result for the
       *  same input.
       *
       *  Note: this is not what you want for codepage conversions.  See
       *  codecvt for that.
       *
       *  @param lo  Pointer to start of range.
       *  @param hi  Pointer to end of range.
       *  @param dfault  Char to use if conversion fails.
       *  @param to  Pointer to the destination array.
       *  @return  @a hi.
      */
      virtual const char_type*
      do_narrow(const char_type* __lo, const char_type* __hi,
		char, char* __dest) const
      {
	memcpy(__dest, __lo, __hi - __lo);
	return __hi;
      }

    private:

      void _M_widen_init() const
      {
	char __tmp[sizeof(_M_widen)];
	for (size_t __i = 0; __i < sizeof(_M_widen); ++__i)
	  __tmp[__i] = __i;
	do_widen(__tmp, __tmp + sizeof(__tmp), _M_widen);

	_M_widen_ok = 1;
	// Set _M_widen_ok to 2 if memcpy can't be used.
	if (memcmp(__tmp, _M_widen, sizeof(_M_widen)))
	  _M_widen_ok = 2;
      }

      // Fill in the narrowing cache and flag whether all values are
      // valid or not.  _M_narrow_ok is set to 2 if memcpy can't
      // be used.
      void _M_narrow_init() const
      {
	char __tmp[sizeof(_M_narrow)];
	for (size_t __i = 0; __i < sizeof(_M_narrow); ++__i)
	  __tmp[__i] = __i;
	do_narrow(__tmp, __tmp + sizeof(__tmp), 0, _M_narrow);

	_M_narrow_ok = 1;
	if (memcmp(__tmp, _M_narrow, sizeof(_M_narrow)))
	  _M_narrow_ok = 2;
	else
	  {
	    // Deal with the special case of zero: renarrow with a
	    // different default and compare.
	    char __c;
	    do_narrow(__tmp, __tmp + 1, 1, &__c);
	    if (__c == 1)
	      _M_narrow_ok = 2;
	  }
      }
    };

  template<>
    const ctype<char>&
    use_facet<ctype<char> >(const locale& __loc);

#ifdef _GLIBCXX_USE_WCHAR_T
  // 22.2.1.3  ctype<wchar_t> specialization
  /**
   *  @brief  The ctype<wchar_t> specialization.
   *
   *  This class defines classification and conversion functions for the
   *  wchar_t type.  It gets used by wchar_t streams for many I/O operations.
   *  The wchar_t specialization provides a number of optimizations as well.
   *
   *  ctype<wchar_t> inherits its public methods from
   *  __ctype_abstract_base<wchar_t>.
  */
  template<>
    class ctype<wchar_t> : public __ctype_abstract_base<wchar_t>
    {
    public:
      // Types:
      /// Typedef for the template parameter wchar_t.
      typedef wchar_t		char_type;
      typedef wctype_t		__wmask_type;

    protected:
      __c_locale		_M_c_locale_ctype;

      // Pre-computed narrowed and widened chars.
      bool                      _M_narrow_ok;
      char                      _M_narrow[128];
      wint_t                    _M_widen[1 + static_cast<unsigned char>(-1)];

      // Pre-computed elements for do_is.
      mask                      _M_bit[16];
      __wmask_type              _M_wmask[16];

    public:
      // Data Members:
      /// The facet id for ctype<wchar_t>
      static locale::id		id;

      /**
       *  @brief  Constructor performs initialization.
       *
       *  This is the constructor provided by the standard.
       *
       *  @param refs  Passed to the base facet class.
      */
      explicit
      ctype(size_t __refs = 0);

      /**
       *  @brief  Constructor performs static initialization.
       *
       *  This constructor is used to construct the initial C locale facet.
       *
       *  @param cloc  Handle to C locale data.
       *  @param refs  Passed to the base facet class.
      */
      explicit
      ctype(__c_locale __cloc, size_t __refs = 0);

    protected:
      __wmask_type
      _M_convert_to_wmask(const mask __m) const;

      /// Destructor
      virtual
      ~ctype();

      /**
       *  @brief  Test wchar_t classification.
       *
       *  This function finds a mask M for @a c and compares it to mask @a m.
       *
       *  do_is() is a hook for a derived facet to change the behavior of
       *  classifying.  do_is() must always return the same result for the
       *  same input.
       *
       *  @param c  The wchar_t to find the mask of.
       *  @param m  The mask to compare against.
       *  @return  (M & m) != 0.
      */
      virtual bool
      do_is(mask __m, char_type __c) const;

      /**
       *  @brief  Return a mask array.
       *
       *  This function finds the mask for each wchar_t in the range [lo,hi)
       *  and successively writes it to vec.  vec must have as many elements
       *  as the input.
       *
       *  do_is() is a hook for a derived facet to change the behavior of
       *  classifying.  do_is() must always return the same result for the
       *  same input.
       *
       *  @param lo  Pointer to start of range.
       *  @param hi  Pointer to end of range.
       *  @param vec  Pointer to an array of mask storage.
       *  @return  @a hi.
      */
      virtual const char_type*
      do_is(const char_type* __lo, const char_type* __hi, mask* __vec) const;

      /**
       *  @brief  Find wchar_t matching mask
       *
       *  This function searches for and returns the first wchar_t c in
       *  [lo,hi) for which is(m,c) is true.
       *
       *  do_scan_is() is a hook for a derived facet to change the behavior of
       *  match searching.  do_is() must always return the same result for the
       *  same input.
       *
       *  @param m  The mask to compare against.
       *  @param lo  Pointer to start of range.
       *  @param hi  Pointer to end of range.
       *  @return  Pointer to a matching wchar_t if found, else @a hi.
      */
      virtual const char_type*
      do_scan_is(mask __m, const char_type* __lo, const char_type* __hi) const;

      /**
       *  @brief  Find wchar_t not matching mask
       *
       *  This function searches for and returns a pointer to the first
       *  wchar_t c of [lo,hi) for which is(m,c) is false.
       *
       *  do_scan_is() is a hook for a derived facet to change the behavior of
       *  match searching.  do_is() must always return the same result for the
       *  same input.
       *
       *  @param m  The mask to compare against.
       *  @param lo  Pointer to start of range.
       *  @param hi  Pointer to end of range.
       *  @return  Pointer to a non-matching wchar_t if found, else @a hi.
      */
      virtual const char_type*
      do_scan_not(mask __m, const char_type* __lo,
		  const char_type* __hi) const;

      /**
       *  @brief  Convert to uppercase.
       *
       *  This virtual function converts the wchar_t argument to uppercase if
       *  possible.  If not possible (for example, '2'), returns the argument.
       *
       *  do_toupper() is a hook for a derived facet to change the behavior of
       *  uppercasing.  do_toupper() must always return the same result for
       *  the same input.
       *
       *  @param c  The wchar_t to convert.
       *  @return  The uppercase wchar_t if convertible, else @a c.
      */
      virtual char_type
      do_toupper(char_type) const;

      /**
       *  @brief  Convert array to uppercase.
       *
       *  This virtual function converts each wchar_t in the range [lo,hi) to
       *  uppercase if possible.  Other elements remain untouched.
       *
       *  do_toupper() is a hook for a derived facet to change the behavior of
       *  uppercasing.  do_toupper() must always return the same result for
       *  the same input.
       *
       *  @param lo  Pointer to start of range.
       *  @param hi  Pointer to end of range.
       *  @return  @a hi.
      */
      virtual const char_type*
      do_toupper(char_type* __lo, const char_type* __hi) const;

      /**
       *  @brief  Convert to lowercase.
       *
       *  This virtual function converts the argument to lowercase if
       *  possible.  If not possible (for example, '2'), returns the argument.
       *
       *  do_tolower() is a hook for a derived facet to change the behavior of
       *  lowercasing.  do_tolower() must always return the same result for
       *  the same input.
       *
       *  @param c  The wchar_t to convert.
       *  @return  The lowercase wchar_t if convertible, else @a c.
      */
      virtual char_type
      do_tolower(char_type) const;

      /**
       *  @brief  Convert array to lowercase.
       *
       *  This virtual function converts each wchar_t in the range [lo,hi) to
       *  lowercase if possible.  Other elements remain untouched.
       *
       *  do_tolower() is a hook for a derived facet to change the behavior of
       *  lowercasing.  do_tolower() must always return the same result for
       *  the same input.
       *
       *  @param lo  Pointer to start of range.
       *  @param hi  Pointer to end of range.
       *  @return  @a hi.
      */
      virtual const char_type*
      do_tolower(char_type* __lo, const char_type* __hi) const;

      /**
       *  @brief  Widen char to wchar_t
       *
       *  This virtual function converts the char to wchar_t using the
       *  simplest reasonable transformation.  For an underived ctype<wchar_t>
       *  facet, the argument will be cast to wchar_t.
       *
       *  do_widen() is a hook for a derived facet to change the behavior of
       *  widening.  do_widen() must always return the same result for the
       *  same input.
       *
       *  Note: this is not what you want for codepage conversions.  See
       *  codecvt for that.
       *
       *  @param c  The char to convert.
       *  @return  The converted wchar_t.
      */
      virtual char_type
      do_widen(char) const;

      /**
       *  @brief  Widen char array to wchar_t array
       *
       *  This function converts each char in the input to wchar_t using the
       *  simplest reasonable transformation.  For an underived ctype<wchar_t>
       *  facet, the argu…