1// Copyright Vladimir Prus 2002-2004.
2// Distributed under the Boost Software License, Version 1.0.
3// (See accompanying file LICENSE_1_0.txt
4// or copy at http://www.boost.org/LICENSE_1_0.txt)
5
6
7#ifndef BOOST_VARIABLES_MAP_VP_2003_05_19
8#define BOOST_VARIABLES_MAP_VP_2003_05_19
9
10#include <boost/program_options/config.hpp>
11
12#include <boost/any.hpp>
13#include <boost/shared_ptr.hpp>
14
15#include <string>
16#include <map>
17#include <set>
18
19#if defined(BOOST_MSVC)
20# pragma warning (push)
21# pragma warning (disable:4251) // 'boost::program_options::variable_value::v' : class 'boost::any' needs to have dll-interface to be used by clients of class 'boost::program_options::variable_value
22#endif
23
24namespace boost { namespace program_options {
25
26 template<class charT>
27 class basic_parsed_options;
28
29 class value_semantic;
30 class variables_map;
31
32 // forward declaration
33
34 /** Stores in 'm' all options that are defined in 'options'.
35 If 'm' already has a non-defaulted value of an option, that value
36 is not changed, even if 'options' specify some value.
37 */
38 BOOST_PROGRAM_OPTIONS_DECL
39 void store(const basic_parsed_options<char>& options, variables_map& m,
40 bool utf8 = false);
41
42 /** Stores in 'm' all options that are defined in 'options'.
43 If 'm' already has a non-defaulted value of an option, that value
44 is not changed, even if 'options' specify some value.
45 This is wide character variant.
46 */
47 BOOST_PROGRAM_OPTIONS_DECL
48 void store(const basic_parsed_options<wchar_t>& options,
49 variables_map& m);
50
51
52 /** Runs all 'notify' function for options in 'm'. */
53 BOOST_PROGRAM_OPTIONS_DECL void notify(variables_map& m);
54
55 /** Class holding value of option. Contains details about how the
56 value is set and allows to conveniently obtain the value.
57 */
58 class BOOST_PROGRAM_OPTIONS_DECL variable_value {
59 public:
60 variable_value() : m_defaulted(false) {}
61 variable_value(const boost::any& xv, bool xdefaulted)
62 : v(xv), m_defaulted(xdefaulted)
63 {}
64
65 /** If stored value if of type T, returns that value. Otherwise,
66 throws boost::bad_any_cast exception. */
67 template<class T>
68 const T& as() const {
69 return boost::any_cast<const T&>(v);
70 }
71 /** @overload */
72 template<class T>
73 T& as() {
74 return boost::any_cast<T&>(v);
75 }
76
77 /// Returns true if no value is stored.
78 bool empty() const;
79 /** Returns true if the value was not explicitly
80 given, but has default value. */
81 bool defaulted() const;
82 /** Returns the contained value. */
83 const boost::any& value() const;
84
85 /** Returns the contained value. */
86 boost::any& value();
87 private:
88 boost::any v;
89 bool m_defaulted;
90 // Internal reference to value semantic. We need to run
91 // notifications when *final* values of options are known, and
92 // they are known only after all sources are stored. By that
93 // time options_description for the first source might not
94 // be easily accessible, so we need to store semantic here.
95 shared_ptr<const value_semantic> m_value_semantic;
96
97 friend BOOST_PROGRAM_OPTIONS_DECL
98 void store(const basic_parsed_options<char>& options,
99 variables_map& m, bool);
100
101 friend class BOOST_PROGRAM_OPTIONS_DECL variables_map;
102 };
103
104 /** Implements string->string mapping with convenient value casting
105 facilities. */
106 class BOOST_PROGRAM_OPTIONS_DECL abstract_variables_map {
107 public:
108 abstract_variables_map();
109 abstract_variables_map(const abstract_variables_map* next);
110
111 virtual ~abstract_variables_map() {}
112
113 /** Obtains the value of variable 'name', from *this and
114 possibly from the chain of variable maps.
115
116 - if there's no value in *this.
117 - if there's next variable map, returns value from it
118 - otherwise, returns empty value
119
120 - if there's defaulted value
121 - if there's next variable map, which has a non-defaulted
122 value, return that
123 - otherwise, return value from *this
124
125 - if there's a non-defaulted value, returns it.
126 */
127 const variable_value& operator[](const std::string& name) const;
128
129 /** Sets next variable map, which will be used to find
130 variables not found in *this. */
131 void next(abstract_variables_map* next);
132
133 private:
134 /** Returns value of variable 'name' stored in *this, or
135 empty value otherwise. */
136 virtual const variable_value& get(const std::string& name) const = 0;
137
138 const abstract_variables_map* m_next;
139 };
140
141 /** Concrete variables map which store variables in real map.
142
143 This class is derived from std::map<std::string, variable_value>,
144 so you can use all map operators to examine its content.
145 */
146 class BOOST_PROGRAM_OPTIONS_DECL variables_map : public abstract_variables_map,
147 public std::map<std::string, variable_value>
148 {
149 public:
150 variables_map();
151 variables_map(const abstract_variables_map* next);
152
153 // Resolve conflict between inherited operators.
154 const variable_value& operator[](const std::string& name) const
155 { return abstract_variables_map::operator[](name); }
156
157 // Override to clear some extra fields.
158 void clear();
159
160 void notify();
161
162 private:
163 /** Implementation of abstract_variables_map::get
164 which does 'find' in *this. */
165 const variable_value& get(const std::string& name) const;
166
167 /** Names of option with 'final' values \-- which should not
168 be changed by subsequence assignments. */
169 std::set<std::string> m_final;
170
171 friend BOOST_PROGRAM_OPTIONS_DECL
172 void store(const basic_parsed_options<char>& options,
173 variables_map& xm,
174 bool utf8);
175
176 /** Names of required options, filled by parser which has
177 access to options_description.
178 The map values are the "canonical" names for each corresponding option.
179 This is useful in creating diagnostic messages when the option is absent. */
180 std::map<std::string, std::string> m_required;
181 };
182
183
184 /*
185 * Templates/inlines
186 */
187
188 inline bool
189 variable_value::empty() const
190 {
191 return v.empty();
192 }
193
194 inline bool
195 variable_value::defaulted() const
196 {
197 return m_defaulted;
198 }
199
200 inline
201 const boost::any&
202 variable_value::value() const
203 {
204 return v;
205 }
206
207 inline
208 boost::any&
209 variable_value::value()
210 {
211 return v;
212 }
213
214}}
215
216#if defined(BOOST_MSVC)
217# pragma warning (pop)
218#endif
219
220#endif
221

source code of boost/libs/program_options/include/boost/program_options/variables_map.hpp