vstring_util.h

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// Versatile string utility -*- C++ -*-

// Copyright (C) 2005, 2006, 2007 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 ext/vstring_util.h
 *  This file is a GNU extension to the Standard C++ Library.
 *  This is an internal header file, included by other library headers.
 *  You should not attempt to use it directly.
 */

#ifndef _VSTRING_UTIL_H
#define _VSTRING_UTIL_H 1

#pragma GCC system_header

#include <ext/vstring_fwd.h>
#include <debug/debug.h>
#include <bits/stl_function.h>  // For less
#include <bits/functexcept.h>
#include <bits/localefwd.h>
#include <bits/ostream_insert.h>
#include <bits/stl_iterator.h>
#include <ext/numeric_traits.h>
#include <bits/stl_move.h>

_GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)

  template<typename _CharT, typename _Traits, typename _Alloc>
    struct __vstring_utility
    {
      typedef typename _Alloc::template rebind<_CharT>::other _CharT_alloc_type;

      typedef _Traits                       traits_type;      
      typedef typename _Traits::char_type           value_type;
      typedef typename _CharT_alloc_type::size_type     size_type;
      typedef typename _CharT_alloc_type::difference_type   difference_type;      
      typedef typename _CharT_alloc_type::pointer       pointer;
      typedef typename _CharT_alloc_type::const_pointer     const_pointer;

      // For __sso_string.
      typedef __gnu_cxx::
      __normal_iterator<pointer, __gnu_cxx::
            __versa_string<_CharT, _Traits, _Alloc,
                       __sso_string_base> >
        __sso_iterator;
      typedef __gnu_cxx::
      __normal_iterator<const_pointer, __gnu_cxx::
            __versa_string<_CharT, _Traits, _Alloc,
                       __sso_string_base> >
        __const_sso_iterator;

      // For __rc_string.
      typedef __gnu_cxx::
      __normal_iterator<pointer, __gnu_cxx::
            __versa_string<_CharT, _Traits, _Alloc,
                       __rc_string_base> >
        __rc_iterator;
      typedef __gnu_cxx::
      __normal_iterator<const_pointer, __gnu_cxx::
            __versa_string<_CharT, _Traits, _Alloc,
                       __rc_string_base> >
        __const_rc_iterator;

      // NB:  When the allocator is empty, deriving from it saves space 
      // (http://www.cantrip.org/emptyopt.html).
      template<typename _Alloc1>
        struct _Alloc_hider
    : public _Alloc1
    {
      _Alloc_hider(_CharT* __ptr)
      : _Alloc1(), _M_p(__ptr) { }

      _Alloc_hider(const _Alloc1& __a, _CharT* __ptr)
      : _Alloc1(__a), _M_p(__ptr) { }

      _CharT*  _M_p; // The actual data.
    };

      // When __n = 1 way faster than the general multichar
      // traits_type::copy/move/assign.
      static void
      _S_copy(_CharT* __d, const _CharT* __s, size_type __n)
      {
    if (__n == 1)
      traits_type::assign(*__d, *__s);
    else
      traits_type::copy(__d, __s, __n);
      }

      static void
      _S_move(_CharT* __d, const _CharT* __s, size_type __n)
      {
    if (__n == 1)
      traits_type::assign(*__d, *__s);
    else
      traits_type::move(__d, __s, __n);   
      }

      static void
      _S_assign(_CharT* __d, size_type __n, _CharT __c)
      {
    if (__n == 1)
      traits_type::assign(*__d, __c);
    else
      traits_type::assign(__d, __n, __c);     
      }

      // _S_copy_chars is a separate template to permit specialization
      // to optimize for the common case of pointers as iterators.
      template<typename _Iterator>
        static void
        _S_copy_chars(_CharT* __p, _Iterator __k1, _Iterator __k2)
        {
      for (; __k1 != __k2; ++__k1, ++__p)
        traits_type::assign(*__p, *__k1); // These types are off.
    }

      static void
      _S_copy_chars(_CharT* __p, __sso_iterator __k1, __sso_iterator __k2)
      { _S_copy_chars(__p, __k1.base(), __k2.base()); }

      static void
      _S_copy_chars(_CharT* __p, __const_sso_iterator __k1,
            __const_sso_iterator __k2)
      { _S_copy_chars(__p, __k1.base(), __k2.base()); }

      static void
      _S_copy_chars(_CharT* __p, __rc_iterator __k1, __rc_iterator __k2)
      { _S_copy_chars(__p, __k1.base(), __k2.base()); }

      static void
      _S_copy_chars(_CharT* __p, __const_rc_iterator __k1,
            __const_rc_iterator __k2)
      { _S_copy_chars(__p, __k1.base(), __k2.base()); }

      static void
      _S_copy_chars(_CharT* __p, _CharT* __k1, _CharT* __k2)
      { _S_copy(__p, __k1, __k2 - __k1); }

      static void
      _S_copy_chars(_CharT* __p, const _CharT* __k1, const _CharT* __k2)
      { _S_copy(__p, __k1, __k2 - __k1); }

      static int
      _S_compare(size_type __n1, size_type __n2)
      {
    const difference_type __d = difference_type(__n1 - __n2);

    if (__d > __numeric_traits_integer<int>::__max)
      return __numeric_traits_integer<int>::__max;
    else if (__d < __numeric_traits_integer<int>::__min)
      return __numeric_traits_integer<int>::__min;
    else
      return int(__d);
      }
    };

_GLIBCXX_END_NAMESPACE

#endif /* _VSTRING_UTIL_H */

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