libstdc++-v3/include/ext/vstring_util.h

   1 // Versatile string utility -*- C++ -*-
   2
   3 // Copyright (C) 2005-2022 Free Software Foundation, Inc.
   4 //
   5 // This file is part of the GNU ISO C++ Library.  This library is free
   6 // software; you can redistribute it and/or modify it under the
   7 // terms of the GNU General Public License as published by the
   8 // Free Software Foundation; either version 3, or (at your option)
   9 // any later version.
  10
  11 // This library is distributed in the hope that it will be useful,
  12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 // GNU General Public License for more details.
  15
  16 // Under Section 7 of GPL version 3, you are granted additional
  17 // permissions described in the GCC Runtime Library Exception, version
  18 // 3.1, as published by the Free Software Foundation.
  19
  20 // You should have received a copy of the GNU General Public License and
  21 // a copy of the GCC Runtime Library Exception along with this program;
  22 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  23 // <http://www.gnu.org/licenses/>.
  24
  25 /** @file ext/vstring_util.h
  26  *  This is an internal header file, included by other library headers.
  27  *  Do not attempt to use it directly. @headername{ext/vstring.h}
  28  */
  29
  30 #ifndef _VSTRING_UTIL_H
  31 #define _VSTRING_UTIL_H 1
  32
  33 #pragma GCC system_header
  34
  35 #include <bits/requires_hosted.h> // GNU extensions are currently omitted
  36
  37 #include <ext/vstring_fwd.h>
  38 #include <debug/debug.h>
  39 #include <bits/stl_function.h>  // For less
  40 #include <bits/functexcept.h>
  41 #include <bits/localefwd.h>
  42 #include <bits/ostream_insert.h>
  43 #include <bits/stl_iterator.h>
  44 #include <ext/numeric_traits.h>
  45 #include <ext/alloc_traits.h>
  46 #include <bits/move.h>
  47 #include <bits/range_access.h>
  48
  49 namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
  50 {
  51 _GLIBCXX_BEGIN_NAMESPACE_VERSION
  52
  53   template<typename _CharT, typename _Traits, typename _Alloc>
  54     struct __vstring_utility
  55     {
  56       typedef typename __alloc_traits<_Alloc>::template rebind<_CharT>::other
  57         _CharT_alloc_type;
  58       typedef __alloc_traits<_CharT_alloc_type> _CharT_alloc_traits;
  59
  60       typedef _Traits                                       traits_type;
  61       typedef typename _Traits::char_type                   value_type;
  62       typedef typename _CharT_alloc_type::size_type         size_type;
  63       typedef typename _CharT_alloc_type::difference_type   difference_type;
  64       typedef typename _CharT_alloc_traits::pointer         pointer;
  65       typedef typename _CharT_alloc_traits::const_pointer   const_pointer;
  66
  67       // For __sso_string.
  68       typedef __gnu_cxx::
  69       __normal_iterator<pointer, __gnu_cxx::
  70                         __versa_string<_CharT, _Traits, _Alloc,
  71                                        __sso_string_base> >
  72         __sso_iterator;
  73       typedef __gnu_cxx::
  74       __normal_iterator<const_pointer, __gnu_cxx::
  75                         __versa_string<_CharT, _Traits, _Alloc,
  76                                        __sso_string_base> >
  77         __const_sso_iterator;
  78
  79       // For __rc_string.
  80       typedef __gnu_cxx::
  81       __normal_iterator<pointer, __gnu_cxx::
  82                         __versa_string<_CharT, _Traits, _Alloc,
  83                                        __rc_string_base> >
  84         __rc_iterator;
  85       typedef __gnu_cxx::
  86       __normal_iterator<const_pointer, __gnu_cxx::
  87                         __versa_string<_CharT, _Traits, _Alloc,
  88                                        __rc_string_base> >
  89         __const_rc_iterator;
  90
  91       // NB:  When the allocator is empty, deriving from it saves space
  92       // (http://www.cantrip.org/emptyopt.html).
  93       template<typename _Alloc1>
  94         struct _Alloc_hider
  95         : public _Alloc1
  96         {
  97           _Alloc_hider(_CharT* __ptr)
  98           : _Alloc1(), _M_p(__ptr) { }
  99
 100           _Alloc_hider(const _Alloc1& __a, _CharT* __ptr)
 101           : _Alloc1(__a), _M_p(__ptr) { }
 102
 103           _CharT*  _M_p; // The actual data.
 104         };
 105
 106       // When __n = 1 way faster than the general multichar
 107       // traits_type::copy/move/assign.
 108       static void
 109       _S_copy(_CharT* __d, const _CharT* __s, size_type __n)
 110       {
 111         if (__n == 1)
 112           traits_type::assign(*__d, *__s);
 113         else
 114           traits_type::copy(__d, __s, __n);
 115       }
 116
 117       static void
 118       _S_move(_CharT* __d, const _CharT* __s, size_type __n)
 119       {
 120         if (__n == 1)
 121           traits_type::assign(*__d, *__s);
 122         else
 123           traits_type::move(__d, __s, __n);
 124       }
 125
 126       static void
 127       _S_assign(_CharT* __d, size_type __n, _CharT __c)
 128       {
 129         if (__n == 1)
 130           traits_type::assign(*__d, __c);
 131         else
 132           traits_type::assign(__d, __n, __c);
 133       }
 134
 135       // _S_copy_chars is a separate template to permit specialization
 136       // to optimize for the common case of pointers as iterators.
 137       template<typename _Iterator>
 138         static void
 139         _S_copy_chars(_CharT* __p, _Iterator __k1, _Iterator __k2)
 140         {
 141           for (; __k1 != __k2; ++__k1, ++__p)
 142             traits_type::assign(*__p, *__k1); // These types are off.
 143         }
 144
 145       static void
 146       _S_copy_chars(_CharT* __p, __sso_iterator __k1, __sso_iterator __k2)
 147       { _S_copy_chars(__p, __k1.base(), __k2.base()); }
 148
 149       static void
 150       _S_copy_chars(_CharT* __p, __const_sso_iterator __k1,
 151                     __const_sso_iterator __k2)
 152       { _S_copy_chars(__p, __k1.base(), __k2.base()); }
 153
 154       static void
 155       _S_copy_chars(_CharT* __p, __rc_iterator __k1, __rc_iterator __k2)
 156       { _S_copy_chars(__p, __k1.base(), __k2.base()); }
 157
 158       static void
 159       _S_copy_chars(_CharT* __p, __const_rc_iterator __k1,
 160                     __const_rc_iterator __k2)
 161       { _S_copy_chars(__p, __k1.base(), __k2.base()); }
 162
 163       static void
 164       _S_copy_chars(_CharT* __p, _CharT* __k1, _CharT* __k2)
 165       { _S_copy(__p, __k1, __k2 - __k1); }
 166
 167       static void
 168       _S_copy_chars(_CharT* __p, const _CharT* __k1, const _CharT* __k2)
 169       { _S_copy(__p, __k1, __k2 - __k1); }
 170
 171       static int
 172       _S_compare(size_type __n1, size_type __n2)
 173       {
 174         const difference_type __d = difference_type(__n1 - __n2);
 175
 176         if (__d > __numeric_traits_integer<int>::__max)
 177           return __numeric_traits_integer<int>::__max;
 178         else if (__d < __numeric_traits_integer<int>::__min)
 179           return __numeric_traits_integer<int>::__min;
 180         else
 181           return int(__d);
 182       }
 183     };
 184
 185 _GLIBCXX_END_NAMESPACE_VERSION
 186 } // namespace
 187
 188 #endif /* _VSTRING_UTIL_H */