libstdc++
vstring_util.h
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1 // Versatile string utility -*- C++ -*-
2 
3 // Copyright (C) 2005-2018 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 <ext/vstring_fwd.h>
36 #include <debug/debug.h>
37 #include <bits/stl_function.h> // For less
38 #include <bits/functexcept.h>
39 #include <bits/localefwd.h>
40 #include <bits/ostream_insert.h>
41 #include <bits/stl_iterator.h>
42 #include <ext/numeric_traits.h>
43 #include <bits/move.h>
44 #include <bits/range_access.h>
45 
46 namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
47 {
48 _GLIBCXX_BEGIN_NAMESPACE_VERSION
49 
50  template<typename _CharT, typename _Traits, typename _Alloc>
51  struct __vstring_utility
52  {
53  typedef typename _Alloc::template rebind<_CharT>::other _CharT_alloc_type;
54 
55  typedef _Traits traits_type;
56  typedef typename _Traits::char_type value_type;
57  typedef typename _CharT_alloc_type::size_type size_type;
58  typedef typename _CharT_alloc_type::difference_type difference_type;
59  typedef typename _CharT_alloc_type::pointer pointer;
60  typedef typename _CharT_alloc_type::const_pointer const_pointer;
61 
62  // For __sso_string.
63  typedef __gnu_cxx::
64  __normal_iterator<pointer, __gnu_cxx::
65  __versa_string<_CharT, _Traits, _Alloc,
66  __sso_string_base> >
67  __sso_iterator;
68  typedef __gnu_cxx::
69  __normal_iterator<const_pointer, __gnu_cxx::
70  __versa_string<_CharT, _Traits, _Alloc,
71  __sso_string_base> >
72  __const_sso_iterator;
73 
74  // For __rc_string.
75  typedef __gnu_cxx::
76  __normal_iterator<pointer, __gnu_cxx::
77  __versa_string<_CharT, _Traits, _Alloc,
78  __rc_string_base> >
79  __rc_iterator;
80  typedef __gnu_cxx::
81  __normal_iterator<const_pointer, __gnu_cxx::
82  __versa_string<_CharT, _Traits, _Alloc,
83  __rc_string_base> >
84  __const_rc_iterator;
85 
86  // NB: When the allocator is empty, deriving from it saves space
87  // (http://www.cantrip.org/emptyopt.html).
88  template<typename _Alloc1>
89  struct _Alloc_hider
90  : public _Alloc1
91  {
92  _Alloc_hider(_CharT* __ptr)
93  : _Alloc1(), _M_p(__ptr) { }
94 
95  _Alloc_hider(const _Alloc1& __a, _CharT* __ptr)
96  : _Alloc1(__a), _M_p(__ptr) { }
97 
98  _CharT* _M_p; // The actual data.
99  };
100 
101  // When __n = 1 way faster than the general multichar
102  // traits_type::copy/move/assign.
103  static void
104  _S_copy(_CharT* __d, const _CharT* __s, size_type __n)
105  {
106  if (__n == 1)
107  traits_type::assign(*__d, *__s);
108  else
109  traits_type::copy(__d, __s, __n);
110  }
111 
112  static void
113  _S_move(_CharT* __d, const _CharT* __s, size_type __n)
114  {
115  if (__n == 1)
116  traits_type::assign(*__d, *__s);
117  else
118  traits_type::move(__d, __s, __n);
119  }
120 
121  static void
122  _S_assign(_CharT* __d, size_type __n, _CharT __c)
123  {
124  if (__n == 1)
125  traits_type::assign(*__d, __c);
126  else
127  traits_type::assign(__d, __n, __c);
128  }
129 
130  // _S_copy_chars is a separate template to permit specialization
131  // to optimize for the common case of pointers as iterators.
132  template<typename _Iterator>
133  static void
134  _S_copy_chars(_CharT* __p, _Iterator __k1, _Iterator __k2)
135  {
136  for (; __k1 != __k2; ++__k1, ++__p)
137  traits_type::assign(*__p, *__k1); // These types are off.
138  }
139 
140  static void
141  _S_copy_chars(_CharT* __p, __sso_iterator __k1, __sso_iterator __k2)
142  { _S_copy_chars(__p, __k1.base(), __k2.base()); }
143 
144  static void
145  _S_copy_chars(_CharT* __p, __const_sso_iterator __k1,
146  __const_sso_iterator __k2)
147  { _S_copy_chars(__p, __k1.base(), __k2.base()); }
148 
149  static void
150  _S_copy_chars(_CharT* __p, __rc_iterator __k1, __rc_iterator __k2)
151  { _S_copy_chars(__p, __k1.base(), __k2.base()); }
152 
153  static void
154  _S_copy_chars(_CharT* __p, __const_rc_iterator __k1,
155  __const_rc_iterator __k2)
156  { _S_copy_chars(__p, __k1.base(), __k2.base()); }
157 
158  static void
159  _S_copy_chars(_CharT* __p, _CharT* __k1, _CharT* __k2)
160  { _S_copy(__p, __k1, __k2 - __k1); }
161 
162  static void
163  _S_copy_chars(_CharT* __p, const _CharT* __k1, const _CharT* __k2)
164  { _S_copy(__p, __k1, __k2 - __k1); }
165 
166  static int
167  _S_compare(size_type __n1, size_type __n2)
168  {
169  const difference_type __d = difference_type(__n1 - __n2);
170 
171  if (__d > __numeric_traits_integer<int>::__max)
172  return __numeric_traits_integer<int>::__max;
173  else if (__d < __numeric_traits_integer<int>::__min)
174  return __numeric_traits_integer<int>::__min;
175  else
176  return int(__d);
177  }
178  };
179 
180 _GLIBCXX_END_NAMESPACE_VERSION
181 } // namespace
182 
183 #endif /* _VSTRING_UTIL_H */
GNU extensions for public use.