f73d090e426cfa7458f6029c57fc9baf9918749f
[libdai.git] / include / dai / enum.h
1 /* Copyright (C) 2006-2008 Joris Mooij [joris dot mooij at tuebingen dot mpg dot de]
2 Radboud University Nijmegen, The Netherlands /
3 Max Planck Institute for Biological Cybernetics, Germany
4
5 This file is part of libDAI.
6
7 libDAI is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2 of the License, or
10 (at your option) any later version.
11
12 libDAI is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
16
17 You should have received a copy of the GNU General Public License
18 along with libDAI; if not, write to the Free Software
19 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22
23 /// \file
24 /// \brief Defines the DAI_ENUM macro
25
26
27 #ifndef __defined_libdai_enum_h
28 #define __defined_libdai_enum_h
29
30
31 #include <cstring>
32 #include <iostream>
33 #include <dai/exceptions.h>
34
35
36 /// Extends the C++ enum type by supporting input/output streaming and conversion to and from const char*
37 /** Example of usage:
38 * \code
39 * DAI_ENUM(colors,RED,GREEN,BLUE)
40 * \endcode
41 * defines a class encapsulating an
42 * \code
43 * enum colors {RED, GREEN, BLUE};
44 * \endcode
45 * It offers additional functionality over the plain "enum" keyword.
46 */
47 #define DAI_ENUM(x,val0,...) class x {\
48 public:\
49 enum value {val0,__VA_ARGS__};\
50 \
51 x() : v(val0) {}\
52 \
53 x(value w) : v(w) {}\
54 \
55 x(char const *w) {\
56 static char const* labelstring = #val0 "," #__VA_ARGS__ ",";\
57 size_t pos_begin = 0;\
58 size_t i = 0;\
59 for( size_t pos_end = 0; labelstring[pos_end] != '\0'; pos_end++ )\
60 if( (labelstring[pos_end] == ',') ) {\
61 if( (strlen( w ) == pos_end - pos_begin) && (strncmp( labelstring + pos_begin, w, pos_end - pos_begin ) == 0) ) {\
62 v = (value)i;\
63 return;\
64 } else {\
65 i++;\
66 pos_begin = pos_end + 1;\
67 }\
68 }\
69 DAI_THROW(UNKNOWN_ENUM_VALUE);\
70 }\
71 \
72 operator value() const { return v; }\
73 \
74 operator size_t() const { return (size_t)v; }\
75 \
76 operator char const*() const {\
77 static char labelstring[] = #val0 "," #__VA_ARGS__;\
78 size_t pos_begin = 0;\
79 size_t i = 0;\
80 for( size_t pos_end = 0; ; pos_end++ )\
81 if( (labelstring[pos_end] == ',') || (labelstring[pos_end] == '\0') ) {\
82 if( (size_t)v == i ) {\
83 labelstring[pos_end] = '\0';\
84 return labelstring + pos_begin;\
85 } else {\
86 i++;\
87 pos_begin = pos_end + 1;\
88 }\
89 }\
90 }\
91 \
92 friend std::istream& operator >> (std::istream& is, x& y) {\
93 std::string s;\
94 is >> s;\
95 y = x(s.c_str());\
96 return is;\
97 }\
98 \
99 friend std::ostream& operator << (std::ostream& os, const x& y) {\
100 os << (const char *)y;\
101 return os;\
102 }\
103 \
104 private:\
105 value v;\
106 };
107
108
109 #endif