locale_facets.h

gcc-you can use this code to learn something about gcc, and inquire further into linux,

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

// Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003
// 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, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
// 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.

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

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

#ifndef _CPP_BITS_LOCFACETS_H
#define _CPP_BITS_LOCFACETS_H	1

#pragma GCC system_header

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

namespace std
{
  // NB: Don't instantiate required wchar_t facets if no wchar_t support.
#ifdef _GLIBCPP_USE_WCHAR_T
# define  _GLIBCPP_NUM_FACETS 28
#else
# define  _GLIBCPP_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, int __base = 10);

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

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

#ifdef _GLIBCPP_USE_LONG_LONG
  template<>
    void
    __convert_to_v(const char*, long long&, ios_base::iostate&, 
		   const __c_locale&, int);

  template<>
    void
    __convert_to_v(const char*, unsigned long long&, ios_base::iostate&, 
		   const __c_locale&, int);
#endif

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

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

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

  // 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.
  // Check to make sure that the __grouping_tmp string constructed in
  // money_get or num_get matches the canonical grouping for a given
  // locale.
  // __grouping_tmp is parsed L to R
  // 1,222,444 == __grouping_tmp of "\1\3\3"
  // __grouping is parsed R to L
  // 1,222,444 == __grouping of "\3" == "\3\3\3"
  template<typename _CharT>
    bool
    __verify_grouping(const basic_string<_CharT>& __grouping, 
		      basic_string<_CharT>& __grouping_tmp);

  // 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 __gbeg != __gend.
  template<typename _CharT>
    _CharT*
    __add_grouping(_CharT* __s, _CharT __sep,  
		   const char* __gbeg, const char* __gend, 
		   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.
  #include <bits/ctype_base.h>

  // Common base for ctype<_CharT>.  
  template<typename _CharT>
    class __ctype_abstract_base : public locale::facet, public ctype_base
    {
    public:
      // Types:
      typedef _CharT char_type;

      bool 
      is(mask __m, char_type __c) const
      { return this->do_is(__m, __c); }

      const char_type*
      is(const char_type *__lo, const char_type *__hi, mask *__vec) const   
      { return this->do_is(__lo, __hi, __vec); }

      const char_type*
      scan_is(mask __m, const char_type* __lo, const char_type* __hi) const
      { return this->do_scan_is(__m, __lo, __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); }

      char_type 
      toupper(char_type __c) const
      { return this->do_toupper(__c); }

      const char_type*
      toupper(char_type *__lo, const char_type* __hi) const
      { return this->do_toupper(__lo, __hi); }

      char_type 
      tolower(char_type __c) const
      { return this->do_tolower(__c); }

      const char_type*
      tolower(char_type* __lo, const char_type* __hi) const
      { return this->do_tolower(__lo, __hi); }

      char_type 
      widen(char __c) const
      { return this->do_widen(__c); }

      const char*
      widen(const char* __lo, const char* __hi, char_type* __to) const
      { return this->do_widen(__lo, __hi, __to); }

      char 
      narrow(char_type __c, char __dfault) const
      { return this->do_narrow(__c, __dfault); }

      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): locale::facet(__refs) { }

      virtual 
      ~__ctype_abstract_base() { }
      
      virtual bool 
      do_is(mask __m, char_type __c) const = 0;

      virtual const char_type*
      do_is(const char_type* __lo, const char_type* __hi, 
	    mask* __vec) const = 0;

      virtual const char_type*
      do_scan_is(mask __m, const char_type* __lo,
		 const char_type* __hi) const = 0;

      virtual const char_type*
      do_scan_not(mask __m, const char_type* __lo, 
		  const char_type* __hi) const = 0;

      virtual char_type 
      do_toupper(char_type) const = 0;

      virtual const char_type*
      do_toupper(char_type* __lo, const char_type* __hi) const = 0;

      virtual char_type 
      do_tolower(char_type) const = 0;

      virtual const char_type*
      do_tolower(char_type* __lo, const char_type* __hi) const = 0;
      
      virtual char_type 
      do_widen(char) const = 0;

      virtual const char*
      do_widen(const char* __lo, const char* __hi, 
	       char_type* __dest) const = 0;

      virtual char 
      do_narrow(char_type, char __dfault) const = 0;

      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.
  template<typename _CharT>
    class ctype : public __ctype_abstract_base<_CharT>
    {
    public:
      // Types:
      typedef _CharT 		  	char_type;
      typedef typename ctype::mask 	mask;

      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.
  template<>
    class ctype<char> : public __ctype_abstract_base<char>
    {
    public:
      // Types:
      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;
      
    public:
      static locale::id        id;
      static const size_t      table_size = 1 + static_cast<unsigned char>(-1);

      explicit 
      ctype(const mask* __table = 0, bool __del = false, size_t __refs = 0);

      explicit 
      ctype(__c_locale __cloc, const mask* __table = 0, bool __del = false, 
	    size_t __refs = 0);

      inline bool 
      is(mask __m, char __c) const;
 
      inline const char*
      is(const char* __lo, const char* __hi, mask* __vec) const;
 
      inline const char*
      scan_is(mask __m, const char* __lo, const char* __hi) const;

      inline const char*
      scan_not(mask __m, const char* __lo, const char* __hi) const;
     
    protected:
      const mask* 
      table() const throw()
      { return _M_table; }

      static const mask* 
      classic_table() throw();

      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) const;

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

      virtual char_type 
      do_tolower(char_type) const;

      virtual const char_type*
      do_tolower(char_type* __lo, const char_type* __hi) const;
      
      virtual char_type 
      do_widen(char) 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<>
    const ctype<char>&
    use_facet<ctype<char> >(const locale& __loc);

#ifdef _GLIBCPP_USE_WCHAR_T
  // 22.2.1.3  ctype<wchar_t> specialization
  template<>
    class ctype<wchar_t> : public __ctype_abstract_base<wchar_t>
    {
    public:
      // Types:
      typedef wchar_t 	       	char_type;
      typedef wctype_t	       	__wmask_type;

    protected:
      __c_locale		_M_c_locale_ctype;

    public:
      // Data Members:
      static locale::id        	id;

      explicit 
      ctype(size_t __refs = 0);

      explicit 
      ctype(__c_locale __cloc, size_t __refs = 0);

    protected:
      __wmask_type
      _M_convert_to_wmask(const mask __m) const;

      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) const;

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

      virtual char_type 
      do_tolower(char_type) const;

      virtual const char_type*
      do_tolower(char_type* __lo, const char_type* __hi) const;
      
      virtual char_type 
      do_widen(char) 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<>
    const ctype<wchar_t>&
    use_facet<ctype<wchar_t> >(const locale& __loc);
#endif //_GLIBCPP_USE_WCHAR_T

  // Include host and configuration specific ctype inlines.
  #include <bits/ctype_inline.h>

  // 22.2.1.2  Template class ctype_byname
  template<typename _CharT>
    class ctype_byname : public ctype<_CharT>
    {
    public:
      typedef _CharT 		char_type;

      explicit 
      ctype_byname(const char* __s, size_t __refs = 0);