1 // POD character, std::char_traits specialization -*- C++ -*-
2 
3 // Copyright (C) 2002, 2003, 2004, 2005 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 2, 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 // You should have received a copy of the GNU General Public License along
17 // with this library; see the file COPYING.  If not, write to the Free
18 // Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
19 // USA.
20 
21 // As a special exception, you may use this file as part of a free software
22 // library without restriction.  Specifically, if other files instantiate
23 // templates or use macros or inline functions from this file, or you compile
24 // this file and link it with other files to produce an executable, this
25 // file does not by itself cause the resulting executable to be covered by
26 // the GNU General Public License.  This exception does not however
27 // invalidate any other reasons why the executable file might be covered by
28 // the GNU General Public License.
29 
30 /** @file ext/pod_char_traits.h
31  *  This file is a GNU extension to the Standard C++ Library.
32  */
33 
34 // Gabriel Dos Reis <gdr@integrable-solutions.net>
35 // Benjamin Kosnik <bkoz@redhat.com>
36 
37 #ifndef _POD_CHAR_TRAITS_H
38 #define _POD_CHAR_TRAITS_H 1
39 
40 #include <string>
41 
42 _GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)
43 
44   // POD character abstraction.
45   // NB: The char_type parameter is a subset of int_type, as to allow
46   // int_type to properly hold the full range of char_type values as
47   // well as EOF.
48   /// @brief A POD class that serves as a character abstraction class.
49   template<typename V, typename I, typename S = mbstate_t>
50     struct character
51     {
52       typedef V				value_type;
53       typedef I				int_type;
54       typedef S				state_type;
55       typedef character<V, I, S>	char_type;
56 
57       value_type	value;
58 
59       template<typename V2>
60         static char_type
61         from(const V2& v)
62         {
63 	  char_type ret = { static_cast<value_type>(v) };
64 	  return ret;
65 	}
66 
67       template<typename V2>
68         static V2
69         to(const char_type& c)
70         {
71 	  V2 ret = { static_cast<V2>(c.value) };
72 	  return ret;
73 	}
74 
75     };
76 
77   template<typename V, typename I, typename S>
78     inline bool
79     operator==(const character<V, I, S>& lhs, const character<V, I, S>& rhs)
80     { return lhs.value == rhs.value; }
81 
82   template<typename V, typename I, typename S>
83     inline bool
84     operator<(const character<V, I, S>& lhs, const character<V, I, S>& rhs)
85     { return lhs.value < rhs.value; }
86 
87 _GLIBCXX_END_NAMESPACE
88 
89 _GLIBCXX_BEGIN_NAMESPACE(std)
90 
91   /// char_traits<__gnu_cxx::character> specialization.
92   template<typename V, typename I, typename S>
93     struct char_traits<__gnu_cxx::character<V, I, S> >
94     {
95       typedef __gnu_cxx::character<V, I, S>	char_type;
96       typedef typename char_type::int_type	int_type;
97       typedef typename char_type::state_type	state_type;
98       typedef fpos<state_type>			pos_type;
99       typedef streamoff				off_type;
100 
101       static void
102       assign(char_type& __c1, const char_type& __c2)
103       { __c1 = __c2; }
104 
105       static bool
106       eq(const char_type& __c1, const char_type& __c2)
107       { return __c1 == __c2; }
108 
109       static bool
110       lt(const char_type& __c1, const char_type& __c2)
111       { return __c1 < __c2; }
112 
113       static int
114       compare(const char_type* __s1, const char_type* __s2, size_t __n)
115       {
116 	for (size_t __i = 0; __i < __n; ++__i)
117 	  if (!eq(__s1[__i], __s2[__i]))
118 	    return lt(__s1[__i], __s2[__i]) ? -1 : 1;
119 	return 0;
120       }
121 
122       static size_t
123       length(const char_type* __s)
124       {
125 	const char_type* __p = __s;
126 	while (__p->value)
127 	  ++__p;
128 	return (__p - __s);
129       }
130 
131       static const char_type*
132       find(const char_type* __s, size_t __n, const char_type& __a)
133       {
134 	for (const char_type* __p = __s; size_t(__p - __s) < __n; ++__p)
135 	  if (*__p == __a)
136 	    return __p;
137 	return 0;
138       }
139 
140       static char_type*
141       move(char_type* __s1, const char_type* __s2, size_t __n)
142       {
143 	return static_cast<char_type*>(std::memmove(__s1, __s2,
144 						    __n * sizeof(char_type)));
145       }
146 
147       static char_type*
148       copy(char_type* __s1, const char_type* __s2, size_t __n)
149       {
150 	std::copy(__s2, __s2 + __n, __s1);
151 	return __s1;
152       }
153 
154       static char_type*
155       assign(char_type* __s, size_t __n, char_type __a)
156       {
157 	std::fill_n(__s, __n, __a);
158         return __s;
159       }
160 
161       static char_type
162       to_char_type(const int_type& __i)
163       { return char_type::template from(__i); }
164 
165       static int_type
166       to_int_type(const char_type& __c)
167       { return char_type::template to<int_type>(__c); }
168 
169       static bool
170       eq_int_type(const int_type& __c1, const int_type& __c2)
171       { return __c1 == __c2; }
172 
173       static int_type
174       eof()
175       {
176 	int_type __r = { -1 };
177 	return __r;
178       }
179 
180       static int_type
181       not_eof(const int_type& __c)
182       { return eq_int_type(__c, eof()) ? int_type() : __c; }
183     };
184 
185 _GLIBCXX_END_NAMESPACE
186 
187 #endif
188