1// Copyright Vladimir Prus 2002-2004.
2// Copyright Bertolt Mildner 2004.
3// Distributed under the Boost Software License, Version 1.0.
4// (See accompanying file LICENSE_1_0.txt
5// or copy at http://www.boost.org/LICENSE_1_0.txt)
6
7
8#ifndef BOOST_OPTION_DESCRIPTION_VP_2003_05_19
9#define BOOST_OPTION_DESCRIPTION_VP_2003_05_19
10
11#include <boost/program_options/config.hpp>
12#include <boost/program_options/errors.hpp>
13#include <boost/program_options/value_semantic.hpp>
14
15#include <boost/function.hpp>
16#include <boost/shared_ptr.hpp>
17#include <boost/detail/workaround.hpp>
18#include <boost/any.hpp>
19
20#include <string>
21#include <vector>
22#include <set>
23#include <map>
24#include <stdexcept>
25#include <utility>
26
27#include <iosfwd>
28
29#if defined(BOOST_MSVC)
30# pragma warning (push)
31# pragma warning (disable:4251) // class 'boost::shared_ptr<T>' needs to have dll-interface to be used by clients of class 'boost::program_options::option_description'
32#endif
33
34
35/** Boost namespace */
36namespace boost {
37/** Namespace for the library. */
38namespace program_options {
39
40 /** Describes one possible command line/config file option. There are two
41 kinds of properties of an option. First describe it syntactically and
42 are used only to validate input. Second affect interpretation of the
43 option, for example default value for it or function that should be
44 called when the value is finally known. Routines which perform parsing
45 never use second kind of properties \-- they are side effect free.
46 @sa options_description
47 */
48 class BOOST_PROGRAM_OPTIONS_DECL option_description {
49 public:
50
51 option_description();
52
53 /** Initializes the object with the passed data.
54
55 Note: it would be nice to make the second parameter auto_ptr,
56 to explicitly pass ownership. Unfortunately, it's often needed to
57 create objects of types derived from 'value_semantic':
58 options_description d;
59 d.add_options()("a", parameter<int>("n")->default_value(1));
60 Here, the static type returned by 'parameter' should be derived
61 from value_semantic.
62
63 Alas, derived->base conversion for auto_ptr does not really work,
64 see
65 http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2000/n1232.pdf
66 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#84
67
68 So, we have to use plain old pointers. Besides, users are not
69 expected to use the constructor directly.
70
71
72 The 'name' parameter is interpreted by the following rules:
73 - if there's no "," character in 'name', it specifies long name
74 - otherwise, the part before "," specifies long name and the part
75 after \-- short name.
76 */
77 option_description(const char* name,
78 const value_semantic* s);
79
80 /** Initializes the class with the passed data.
81 */
82 option_description(const char* name,
83 const value_semantic* s,
84 const char* description);
85
86 virtual ~option_description();
87
88 enum match_result { no_match, full_match, approximate_match };
89
90 /** Given 'option', specified in the input source,
91 returns 'true' if 'option' specifies *this.
92 */
93 match_result match(const std::string& option, bool approx,
94 bool long_ignore_case, bool short_ignore_case) const;
95
96 /** Returns the key that should identify the option, in
97 particular in the variables_map class.
98 The 'option' parameter is the option spelling from the
99 input source.
100 If option name contains '*', returns 'option'.
101 If long name was specified, it's the long name, otherwise
102 it's a short name with prepended '-'.
103 */
104 const std::string& key(const std::string& option) const;
105
106
107 /** Returns the canonical name for the option description to enable the user to
108 recognised a matching option.
109 1) For short options ('-', '/'), returns the short name prefixed.
110 2) For long options ('--' / '-') returns the first long name prefixed
111 3) All other cases, returns the first long name (if present) or the short
112 name, unprefixed.
113 */
114 std::string canonical_display_name(int canonical_option_style = 0) const;
115
116 const std::string& long_name() const;
117
118 const std::pair<const std::string*, std::size_t> long_names() const;
119
120 /// Explanation of this option
121 const std::string& description() const;
122
123 /// Semantic of option's value
124 shared_ptr<const value_semantic> semantic() const;
125
126 /// Returns the option name, formatted suitably for usage message.
127 std::string format_name() const;
128
129 /** Returns the parameter name and properties, formatted suitably for
130 usage message. */
131 std::string format_parameter() const;
132
133 private:
134
135 option_description& set_names(const char* name);
136
137 /**
138 * a one-character "switch" name - with its prefix,
139 * so that this is either empty or has length 2 (e.g. "-c"
140 */
141 std::string m_short_name;
142
143 /**
144 * one or more names by which this option may be specified
145 * on a command-line or in a config file, which are not
146 * a single-letter switch. The names here are _without_
147 * any prefix.
148 */
149 std::vector<std::string> m_long_names;
150
151 std::string m_description;
152
153 // shared_ptr is needed to simplify memory management in
154 // copy ctor and destructor.
155 shared_ptr<const value_semantic> m_value_semantic;
156 };
157
158 class options_description;
159
160 /** Class which provides convenient creation syntax to option_description.
161 */
162 class BOOST_PROGRAM_OPTIONS_DECL options_description_easy_init {
163 public:
164 options_description_easy_init(options_description* owner);
165
166 options_description_easy_init&
167 operator()(const char* name,
168 const char* description);
169
170 options_description_easy_init&
171 operator()(const char* name,
172 const value_semantic* s);
173
174 options_description_easy_init&
175 operator()(const char* name,
176 const value_semantic* s,
177 const char* description);
178
179 private:
180 options_description* owner;
181 };
182
183
184 /** A set of option descriptions. This provides convenient interface for
185 adding new option (the add_options) method, and facilities to search
186 for options by name.
187
188 See @ref a_adding_options "here" for option adding interface discussion.
189 @sa option_description
190 */
191 class BOOST_PROGRAM_OPTIONS_DECL options_description {
192 public:
193 static const unsigned m_default_line_length;
194
195 /** Creates the instance. */
196 options_description(unsigned line_length = m_default_line_length,
197 unsigned min_description_length = m_default_line_length / 2);
198 /** Creates the instance. The 'caption' parameter gives the name of
199 this 'options_description' instance. Primarily useful for output.
200 The 'description_length' specifies the number of columns that
201 should be reserved for the description text; if the option text
202 encroaches into this, then the description will start on the next
203 line.
204 */
205 options_description(const std::string& caption,
206 unsigned line_length = m_default_line_length,
207 unsigned min_description_length = m_default_line_length / 2);
208 /** Adds new variable description. Throws duplicate_variable_error if
209 either short or long name matches that of already present one.
210 */
211 void add(shared_ptr<option_description> desc);
212 /** Adds a group of option description. This has the same
213 effect as adding all option_descriptions in 'desc'
214 individually, except that output operator will show
215 a separate group.
216 Returns *this.
217 */
218 options_description& add(const options_description& desc);
219
220 /** Find the maximum width of the option column, including options
221 in groups. */
222 unsigned get_option_column_width() const;
223
224 public:
225 /** Returns an object of implementation-defined type suitable for adding
226 options to options_description. The returned object will
227 have overloaded operator() with parameter type matching
228 'option_description' constructors. Calling the operator will create
229 new option_description instance and add it.
230 */
231 options_description_easy_init add_options();
232
233 const option_description& find(const std::string& name,
234 bool approx,
235 bool long_ignore_case = false,
236 bool short_ignore_case = false) const;
237
238 const option_description* find_nothrow(const std::string& name,
239 bool approx,
240 bool long_ignore_case = false,
241 bool short_ignore_case = false) const;
242
243
244 const std::vector< shared_ptr<option_description> >& options() const;
245
246 /** Produces a human readable output of 'desc', listing options,
247 their descriptions and allowed parameters. Other options_description
248 instances previously passed to add will be output separately. */
249 friend BOOST_PROGRAM_OPTIONS_DECL std::ostream& operator<<(std::ostream& os,
250 const options_description& desc);
251
252 /** Outputs 'desc' to the specified stream, calling 'f' to output each
253 option_description element. */
254 void print(std::ostream& os, unsigned width = 0) const;
255
256 private:
257#if BOOST_WORKAROUND(BOOST_MSVC, BOOST_TESTED_AT(1800))
258 // prevent warning C4512: assignment operator could not be generated
259 options_description& operator=(const options_description&);
260#endif
261
262 typedef std::map<std::string, int>::const_iterator name2index_iterator;
263 typedef std::pair<name2index_iterator, name2index_iterator>
264 approximation_range;
265
266 //approximation_range find_approximation(const std::string& prefix) const;
267
268 std::string m_caption;
269 const unsigned m_line_length;
270 const unsigned m_min_description_length;
271
272 // Data organization is chosen because:
273 // - there could be two names for one option
274 // - option_add_proxy needs to know the last added option
275 std::vector< shared_ptr<option_description> > m_options;
276
277 // Whether the option comes from one of declared groups.
278#if BOOST_WORKAROUND(BOOST_DINKUMWARE_STDLIB, BOOST_TESTED_AT(313))
279 // vector<bool> is buggy there, see
280 // http://support.microsoft.com/default.aspx?scid=kb;en-us;837698
281 std::vector<char> belong_to_group;
282#else
283 std::vector<bool> belong_to_group;
284#endif
285
286 std::vector< shared_ptr<options_description> > groups;
287
288 };
289
290 /** Class thrown when duplicate option description is found. */
291 class BOOST_PROGRAM_OPTIONS_DECL duplicate_option_error : public error {
292 public:
293 duplicate_option_error(const std::string& xwhat) : error(xwhat) {}
294 };
295}}
296
297#if defined(BOOST_MSVC)
298# pragma warning (pop)
299#endif
300
301#endif
302

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