vstring_util.h

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00001 // Versatile string utility -*- C++ -*-
00002 
00003 // Copyright (C) 2005, 2006 Free Software Foundation, Inc.
00004 //
00005 // This file is part of the GNU ISO C++ Library.  This library is free
00006 // software; you can redistribute it and/or modify it under the
00007 // terms of the GNU General Public License as published by the
00008 // Free Software Foundation; either version 2, or (at your option)
00009 // any later version.
00010 
00011 // This library is distributed in the hope that it will be useful,
00012 // but WITHOUT ANY WARRANTY; without even the implied warranty of
00013 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00014 // GNU General Public License for more details.
00015 
00016 // You should have received a copy of the GNU General Public License along
00017 // with this library; see the file COPYING.  If not, write to the Free
00018 // Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
00019 // USA.
00020 
00021 // As a special exception, you may use this file as part of a free software
00022 // library without restriction.  Specifically, if other files instantiate
00023 // templates or use macros or inline functions from this file, or you compile
00024 // this file and link it with other files to produce an executable, this
00025 // file does not by itself cause the resulting executable to be covered by
00026 // the GNU General Public License.  This exception does not however
00027 // invalidate any other reasons why the executable file might be covered by
00028 // the GNU General Public License.
00029 
00030 /** @file ext/vstring_util.h
00031  *  This file is a GNU extension to the Standard C++ Library.
00032  *  This is an internal header file, included by other library headers.
00033  *  You should not attempt to use it directly.
00034  */
00035 
00036 #ifndef _VSTRING_UTIL_H
00037 #define _VSTRING_UTIL_H 1
00038 
00039 #pragma GCC system_header
00040 
00041 #include <ext/vstring_fwd.h>
00042 #include <debug/debug.h>
00043 #include <bits/stl_function.h>  // For less
00044 #include <bits/functexcept.h>
00045 #include <locale>
00046 #include <algorithm> // For std::distance, srd::search.
00047 
00048 namespace __gnu_cxx
00049 {
00050   template<typename _CharT, typename _Traits, typename _Alloc>
00051     struct __vstring_utility
00052     {
00053       typedef typename _Alloc::template rebind<_CharT>::other _CharT_alloc_type;
00054 
00055       typedef _Traits                       traits_type;      
00056       typedef typename _Traits::char_type           value_type;
00057       typedef typename _CharT_alloc_type::size_type     size_type;
00058       typedef typename _CharT_alloc_type::pointer       pointer;
00059       typedef typename _CharT_alloc_type::const_pointer     const_pointer;
00060 
00061       // For __sso_string.
00062       typedef __gnu_cxx::
00063       __normal_iterator<pointer, __gnu_cxx::
00064             __versa_string<_CharT, _Traits, _Alloc,
00065                        __sso_string_base> >
00066         __sso_iterator;
00067       typedef __gnu_cxx::
00068       __normal_iterator<const_pointer, __gnu_cxx::
00069             __versa_string<_CharT, _Traits, _Alloc,
00070                        __sso_string_base> >
00071         __const_sso_iterator;
00072 
00073       // For __rc_string.
00074       typedef __gnu_cxx::
00075       __normal_iterator<pointer, __gnu_cxx::
00076             __versa_string<_CharT, _Traits, _Alloc,
00077                        __rc_string_base> >
00078         __rc_iterator;
00079       typedef __gnu_cxx::
00080       __normal_iterator<const_pointer, __gnu_cxx::
00081             __versa_string<_CharT, _Traits, _Alloc,
00082                        __rc_string_base> >
00083         __const_rc_iterator;
00084 
00085       // NB:  When the allocator is empty, deriving from it saves space 
00086       // (http://www.cantrip.org/emptyopt.html).
00087       template<typename _Alloc1>
00088         struct _Alloc_hider
00089     : public _Alloc1
00090     {
00091       _Alloc_hider(const _Alloc1& __a, _CharT* __ptr)
00092       : _Alloc1(__a), _M_p(__ptr) { }
00093 
00094       _CharT*  _M_p; // The actual data.
00095     };
00096 
00097       // For use in _M_construct (_S_construct) forward_iterator_tag.
00098       template<typename _Type>
00099         static bool
00100         _S_is_null_pointer(_Type* __ptr)
00101         { return __ptr == 0; }
00102 
00103       template<typename _Type>
00104         static bool
00105         _S_is_null_pointer(_Type)
00106         { return false; }
00107 
00108       // When __n = 1 way faster than the general multichar
00109       // traits_type::copy/move/assign.
00110       static void
00111       _S_copy(_CharT* __d, const _CharT* __s, size_type __n)
00112       {
00113     if (__n == 1)
00114       traits_type::assign(*__d, *__s);
00115     else
00116       traits_type::copy(__d, __s, __n);
00117       }
00118 
00119       static void
00120       _S_move(_CharT* __d, const _CharT* __s, size_type __n)
00121       {
00122     if (__n == 1)
00123       traits_type::assign(*__d, *__s);
00124     else
00125       traits_type::move(__d, __s, __n);   
00126       }
00127 
00128       static void
00129       _S_assign(_CharT* __d, size_type __n, _CharT __c)
00130       {
00131     if (__n == 1)
00132       traits_type::assign(*__d, __c);
00133     else
00134       traits_type::assign(__d, __n, __c);     
00135       }
00136 
00137       // _S_copy_chars is a separate template to permit specialization
00138       // to optimize for the common case of pointers as iterators.
00139       template<typename _Iterator>
00140         static void
00141         _S_copy_chars(_CharT* __p, _Iterator __k1, _Iterator __k2)
00142         {
00143       for (; __k1 != __k2; ++__k1, ++__p)
00144         traits_type::assign(*__p, *__k1); // These types are off.
00145     }
00146 
00147       static void
00148       _S_copy_chars(_CharT* __p, __sso_iterator __k1, __sso_iterator __k2)
00149       { _S_copy_chars(__p, __k1.base(), __k2.base()); }
00150 
00151       static void
00152       _S_copy_chars(_CharT* __p, __const_sso_iterator __k1,
00153             __const_sso_iterator __k2)
00154       { _S_copy_chars(__p, __k1.base(), __k2.base()); }
00155 
00156       static void
00157       _S_copy_chars(_CharT* __p, __rc_iterator __k1, __rc_iterator __k2)
00158       { _S_copy_chars(__p, __k1.base(), __k2.base()); }
00159 
00160       static void
00161       _S_copy_chars(_CharT* __p, __const_rc_iterator __k1,
00162             __const_rc_iterator __k2)
00163       { _S_copy_chars(__p, __k1.base(), __k2.base()); }
00164 
00165       static void
00166       _S_copy_chars(_CharT* __p, _CharT* __k1, _CharT* __k2)
00167       { _S_copy(__p, __k1, __k2 - __k1); }
00168 
00169       static void
00170       _S_copy_chars(_CharT* __p, const _CharT* __k1, const _CharT* __k2)
00171       { _S_copy(__p, __k1, __k2 - __k1); }
00172     };
00173 } // namespace __gnu_cxx
00174 
00175 namespace std
00176 {
00177   // To implement Option 3 of DR 431 (vstring only in 4_1-branch).
00178   template<typename _Alloc, bool = std::__is_empty<_Alloc>::__value>
00179     struct __alloc_swap
00180     { static void _S_do_it(_Alloc&, _Alloc&) { } };
00181 
00182   template<typename _Alloc>
00183     struct __alloc_swap<_Alloc, false>
00184     {
00185       static void
00186       _S_do_it(_Alloc& __one, _Alloc& __two)
00187       {
00188     // Precondition: swappable allocators.
00189     if (__one != __two)
00190       swap(__one, __two);
00191       }
00192     };
00193 }
00194 
00195 #endif /* _VSTRING_UTIL_H */

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