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| 15 | <h1><img src="../../../boost.png" alt="boost.png (6897 bytes)" align= |
| 16 | "middle" width="277" height="86">Boost.MultiIndex Examples</h1> |
| 17 | |
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| 19 | Performance |
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| 22 | Index |
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| 27 | |
| 28 | <hr> |
| 29 | |
| 30 | <h2>Contents</h2> |
| 31 | |
| 32 | <ul> |
| 33 | <li><a href="#example1">Example 1: basic usage</a></li> |
| 34 | <li><a href="#example2">Example 2: using functions as keys</a></li> |
| 35 | <li><a href="#example3">Example 3: constructing <code>multi_index_container</code>s |
| 36 | with <code>ctor_args_list</code></a></li> |
| 37 | <li><a href="#example4">Example 4: bidirectional map</a></li> |
| 38 | <li><a href="#example5">Example 5: sequenced indices</a></li> |
| 39 | <li><a href="#example6">Example 6: complex searches and foreign keys</a></li> |
| 40 | <li><a href="#example7">Example 7: composite keys</a></li> |
| 41 | <li><a href="#example8">Example 8: hashed indices</a></li> |
| 42 | <li><a href="#example9">Example 9: serialization and MRU lists</a></li> |
| 43 | <li><a href="#example10">Example 10: random access indices</a></li> |
| 44 | <li><a href="#example11">Example 11: index rearrangement</a></li> |
| 45 | <li><a href="#example12">Example 12: using Boost.Interprocess allocators</a></li> |
| 46 | </ul> |
| 47 | |
| 48 | <h2><a name="example1">Example 1: basic usage</a></h2> |
| 49 | |
| 50 | <p> |
| 51 | See <a href="../example/basic.cpp">source code</a>. |
| 52 | </p> |
| 53 | |
| 54 | <p> |
| 55 | Basic program showing the multi-indexing capabilities of Boost.MultiIndex |
| 56 | with an admittedly boring set of <code>employee</code> records. |
| 57 | </p> |
| 58 | |
| 59 | <h2><a name="example2">Example 2: using functions as keys</a></h2> |
| 60 | |
| 61 | <p> |
| 62 | See <a href="../example/fun_key.cpp">source code</a>. |
| 63 | </p> |
| 64 | |
| 65 | <p> |
| 66 | Usually keys assigned to an index are based on a member variable of the |
| 67 | element, but key extractors can be defined which take their value from |
| 68 | a member function or a global function. This has some similarity with the concept of |
| 69 | <i>calculated keys</i> supported by some relational database engines. |
| 70 | The example shows how to use the predefined <code>const_mem_fun</code> |
| 71 | and <code>global_fun</code> key extractors to deal with this situation. |
| 72 | </p> |
| 73 | |
| 74 | <p> |
| 75 | Keys based on functions usually will not be actual references, |
| 76 | but rather the temporary values resulting from the invocation of the |
| 77 | member function used. This implies that <code>modify_key</code> cannot be |
| 78 | applied to this type of extractors, which is a perfectly logical |
| 79 | constraint anyway. |
| 80 | </p> |
| 81 | |
| 82 | <h2><a name="example3">Example 3: constructing <code>multi_index_container</code>s |
| 83 | with <code>ctor_args_list</code></a></h2> |
| 84 | |
| 85 | <p> |
| 86 | See <a href="../example/non_default_ctor.cpp">source code</a>. |
| 87 | </p> |
| 88 | |
| 89 | <p> |
| 90 | We show a practical example of usage of <code>multi_index_container::ctor_arg_list</code>, |
| 91 | whose definition and purpose are explained in the |
| 92 | <a href="tutorial/creation.html#ctor_args_list">tutorial</a>. The |
| 93 | program groups a sorted collection of numbers based on identification through |
| 94 | modulo arithmetics, by which <code>x</code> and <code>y</code> are equivalent |
| 95 | if <code>(x%n)==(y%n)</code>, for some fixed <code>n</code>. |
| 96 | </p> |
| 97 | |
| 98 | <h2><a name="example4">Example 4: bidirectional map</a></h2> |
| 99 | |
| 100 | <p> |
| 101 | See <a href="../example/bimap.cpp">source code</a>. |
| 102 | </p> |
| 103 | |
| 104 | <p> |
| 105 | This example shows how to construct a bidirectional map with |
| 106 | <code>multi_index_container</code>. By a <i>bidirectional map</i> we mean |
| 107 | a container of <code>(const FromType,const ToType)</code> pairs |
| 108 | such that no two elements exists with the same first |
| 109 | <i>or</i> second component (<code>std::map</code> only |
| 110 | guarantees uniqueness of the first component). Fast lookup is provided |
| 111 | for both keys. The program features a tiny Spanish-English |
| 112 | dictionary with online query of words in both languages. |
| 113 | </p> |
| 114 | |
| 115 | <p> |
| 116 | This bidirectional map can be considered as a primitive precursor |
| 117 | to the full-fledged container provided by |
| 118 | <a href="../../bimap/index.html">Boost.Bimap</a>. |
| 119 | </p> |
| 120 | |
| 121 | <h2><a name="example5">Example 5: sequenced indices</a></h2> |
| 122 | |
| 123 | <p> |
| 124 | See <a href="../example/sequenced.cpp">source code</a>. |
| 125 | </p> |
| 126 | |
| 127 | <p> |
| 128 | The combination of a sequenced index with an index of type <code>ordered_non_unique</code> |
| 129 | yields a <code>list</code>-like structure with fast lookup capabilities. The |
| 130 | example performs some operations on a given text, like word counting and |
| 131 | selective deletion of some words. |
| 132 | </p> |
| 133 | |
| 134 | <h2><a name="example6">Example 6: complex searches and foreign keys</a></h2> |
| 135 | |
| 136 | <p> |
| 137 | See <a href="../example/complex_structs.cpp">source code</a>. |
| 138 | </p> |
| 139 | |
| 140 | <p> |
| 141 | This program illustrates some advanced techniques that can be applied |
| 142 | for complex data structures using <code>multi_index_container</code>. |
| 143 | Consider a <code>car_model</code> class for storing information |
| 144 | about automobiles. On a first approach, <code>car_model</code> can |
| 145 | be defined as: |
| 146 | </p> |
| 147 | |
| 148 | <blockquote><pre> |
| 149 | <span class=keyword>struct</span> <span class=identifier>car_model</span> |
| 150 | <span class=special>{</span> |
| 151 | <span class=identifier>std</span><span class=special>::</span><span class=identifier>string</span> <span class=identifier>model</span><span class=special>;</span> |
| 152 | <span class=identifier>std</span><span class=special>::</span><span class=identifier>string</span> <span class=identifier>manufacturer</span><span class=special>;</span> |
| 153 | <span class=keyword>int</span> <span class=identifier>price</span><span class=special>;</span> |
| 154 | <span class=special>};</span> |
| 155 | </pre></blockquote> |
| 156 | |
| 157 | <p> |
| 158 | This definition has a design flaw that any reader acquainted with |
| 159 | relational databases can easily spot: The <code>manufacturer</code> |
| 160 | member is duplicated among all cars having the same manufacturer. |
| 161 | This is a waste of space and poses difficulties when, for instance, |
| 162 | the name of a manufacturer has to be changed. Following the usual |
| 163 | principles in relational database design, the appropriate design |
| 164 | involves having the manufactures stored in a separate |
| 165 | <code>multi_index_container</code> and store pointers to these in |
| 166 | <code>car_model</code>: |
| 167 | </p> |
| 168 | |
| 169 | <blockquote><pre> |
| 170 | <span class=keyword>struct</span> <span class=identifier>car_manufacturer</span> |
| 171 | <span class=special>{</span> |
| 172 | <span class=identifier>std</span><span class=special>::</span><span class=identifier>string</span> <span class=identifier>name</span><span class=special>;</span> |
| 173 | <span class=special>};</span> |
| 174 | |
| 175 | <span class=keyword>struct</span> <span class=identifier>car_model</span> |
| 176 | <span class=special>{</span> |
| 177 | <span class=identifier>std</span><span class=special>::</span><span class=identifier>string</span> <span class=identifier>model</span><span class=special>;</span> |
| 178 | <span class=identifier>car_manufacturer</span><span class=special>*</span> <span class=identifier>manufacturer</span><span class=special>;</span> |
| 179 | <span class=keyword>int</span> <span class=identifier>price</span><span class=special>;</span> |
| 180 | <span class=special>};</span> |
| 181 | </pre></blockquote> |
| 182 | |
| 183 | <p> |
| 184 | Although predefined Boost.MultiIndex key extractors can handle many |
| 185 | situations involving pointers (see |
| 186 | <a href="tutorial/key_extraction.html#advanced_key_extractors">advanced features |
| 187 | of Boost.MultiIndex key extractors</a> in the tutorial), this case |
| 188 | is complex enough that a suitable key extractor has to be defined. The following |
| 189 | utility cascades two key extractors: |
| 190 | </p> |
| 191 | |
| 192 | <blockquote><pre> |
| 193 | <span class=keyword>template</span><span class=special><</span><span class=keyword>class</span> <span class=identifier>KeyExtractor1</span><span class=special>,</span><span class=keyword>class</span> <span class=identifier>KeyExtractor2</span><span class=special>></span> |
| 194 | <span class=keyword>struct</span> <span class=identifier>key_from_key</span> |
| 195 | <span class=special>{</span> |
| 196 | <span class=keyword>public</span><span class=special>:</span> |
| 197 | <span class=keyword>typedef</span> <span class=keyword>typename</span> <span class=identifier>KeyExtractor1</span><span class=special>::</span><span class=identifier>result_type</span> <span class=identifier>result_type</span><span class=special>;</span> |
| 198 | |
| 199 | <span class=identifier>key_from_key</span><span class=special>(</span> |
| 200 | <span class=keyword>const</span> <span class=identifier>KeyExtractor1</span><span class=special>&</span> <span class=identifier>key1_</span><span class=special>=</span><span class=identifier>KeyExtractor1</span><span class=special>(),</span> |
| 201 | <span class=keyword>const</span> <span class=identifier>KeyExtractor2</span><span class=special>&</span> <span class=identifier>key2_</span><span class=special>=</span><span class=identifier>KeyExtractor2</span><span class=special>()):</span> |
| 202 | <span class=identifier>key1</span><span class=special>(</span><span class=identifier>key1_</span><span class=special>),</span><span class=identifier>key2</span><span class=special>(</span><span class=identifier>key2_</span><span class=special>)</span> |
| 203 | <span class=special>{}</span> |
| 204 | |
| 205 | <span class=keyword>template</span><span class=special><</span><span class=keyword>typename</span> <span class=identifier>Arg</span><span class=special>></span> |
| 206 | <span class=identifier>result_type</span> <span class=keyword>operator</span><span class=special>()(</span><span class=identifier>Arg</span><span class=special>&</span> <span class=identifier>arg</span><span class=special>)</span><span class=keyword>const</span> |
| 207 | <span class=special>{</span> |
| 208 | <span class=keyword>return</span> <span class=identifier>key1</span><span class=special>(</span><span class=identifier>key2</span><span class=special>(</span><span class=identifier>arg</span><span class=special>));</span> |
| 209 | <span class=special>}</span> |
| 210 | |
| 211 | <span class=keyword>private</span><span class=special>:</span> |
| 212 | <span class=identifier>KeyExtractor1</span> <span class=identifier>key1</span><span class=special>;</span> |
| 213 | <span class=identifier>KeyExtractor2</span> <span class=identifier>key2</span><span class=special>;</span> |
| 214 | <span class=special>};</span> |
| 215 | </pre></blockquote> |
| 216 | |
| 217 | <p> |
| 218 | so that access from a <code>car_model</code> to the <code>name</code> field |
| 219 | of its associated <code>car_manufacturer</code> can be accomplished with |
| 220 | </p> |
| 221 | |
| 222 | <blockquote><pre> |
| 223 | <span class=identifier>key_from_key</span><span class=special><</span> |
| 224 | <span class=identifier>member</span><span class=special><</span><span class=identifier>car_manufacturer</span><span class=special>,</span><span class=keyword>const</span> <span class=identifier>std</span><span class=special>::</span><span class=identifier>string</span><span class=special>,&</span><span class=identifier>car_manufacturer</span><span class=special>::</span><span class=identifier>name</span><span class=special>>,</span> |
| 225 | <span class=identifier>member</span><span class=special><</span><span class=identifier>car_model</span><span class=special>,</span><span class=keyword>const</span> <span class=identifier>car_manufacturer</span> <span class=special>*,</span><span class=identifier>car_model</span><span class=special>::</span><span class=identifier>manufacturer</span><span class=special>></span> |
| 226 | <span class=special>></span> |
| 227 | </pre></blockquote> |
| 228 | |
| 229 | <p> |
| 230 | The program asks the user for a car manufacturer and a range of prices |
| 231 | and returns the car models satisfying these requirements. This is a complex |
| 232 | search that cannot be performed on a single operation. Broadly sketched, |
| 233 | one procedure for executing the selection is: |
| 234 | <ol> |
| 235 | <li>Select the elements with the given manufacturer by means |
| 236 | of <code>equal_range</code>, |
| 237 | <li>feed these elements into a <code>multi_index_container</code> sorted |
| 238 | by price, |
| 239 | <li>select by price using <code>lower_bound</code> and |
| 240 | <code>upper_bound</code>; |
| 241 | </ol> |
| 242 | or alternatively: |
| 243 | <ol> |
| 244 | <li>Select the elements within the price range with |
| 245 | <code>lower_bound</code> and <code>upper_bound</code>, |
| 246 | <li>feed these elements into a <code>multi_index_container</code> sorted |
| 247 | by manufacturer, |
| 248 | <li>locate the elements with given manufacturer using |
| 249 | <code>equal_range</code>. |
| 250 | </ol> |
| 251 | An interesting technique developed in the example lies in |
| 252 | the construction of the intermediate <code>multi_index_container</code>. |
| 253 | In order to avoid object copying, appropriate <i>view</i> types |
| 254 | are defined with <code>multi_index_container</code>s having as elements |
| 255 | pointers to <code>car_model</code>s instead of actual objects. |
| 256 | These views have to be supplemented with appropriate |
| 257 | dereferencing key extractors. |
| 258 | </p> |
| 259 | |
| 260 | <h2><a name="example7">Example 7: composite keys</a></h2> |
| 261 | |
| 262 | <p> |
| 263 | See <a href="../example/composite_keys.cpp">source code</a>. |
| 264 | </p> |
| 265 | |
| 266 | <p> |
| 267 | Boost.MultiIndex <a href="tutorial/key_extraction.html#composite_keys"> |
| 268 | <code>composite_key</code></a> construct provides a flexible tool for |
| 269 | creating indices with non-trivial sorting criteria. |
| 270 | The program features a rudimentary simulation of a file system |
| 271 | along with an interactive Unix-like shell. A file entry is represented by |
| 272 | the following structure: |
| 273 | </p> |
| 274 | |
| 275 | <blockquote><pre> |
| 276 | <span class=keyword>struct</span> <span class=identifier>file_entry</span> |
| 277 | <span class=special>{</span> |
| 278 | <span class=identifier>std</span><span class=special>::</span><span class=identifier>string</span> <span class=identifier>name</span><span class=special>;</span> |
| 279 | <span class=keyword>unsigned</span> <span class=identifier>size</span><span class=special>;</span> |
| 280 | <span class=keyword>bool</span> <span class=identifier>is_dir</span><span class=special>;</span> <span class=comment>// true if the entry is a directory</span> |
| 281 | <span class=keyword>const</span> <span class=identifier>file_entry</span><span class=special>*</span> <span class=identifier>dir</span><span class=special>;</span> <span class=comment>// directory this entry belongs in</span> |
| 282 | <span class=special>};</span> |
| 283 | </pre></blockquote> |
| 284 | |
| 285 | <p> |
| 286 | Entries are kept in a <code>multi_index_container</code> maintaining two indices |
| 287 | with composite keys: |
| 288 | <ul> |
| 289 | <li>A primary index ordered by directory and name,</li> |
| 290 | <li>a secondary index ordered by directory and size.</li> |
| 291 | </ul> |
| 292 | The reason that the order is made firstly by the directory in which |
| 293 | the files are located obeys to the local nature of the shell commands, |
| 294 | like for instance <code>ls</code>. The shell simulation only has three |
| 295 | commands: |
| 296 | <ul> |
| 297 | <li><code>cd [.|..|<i><directory></i>]</code></li> |
| 298 | <li><code>ls [-s]</code> (<code>-s</code> orders the output by size)</li> |
| 299 | <li><code>mkdir <i><directory></i></code></li> |
| 300 | </ul> |
| 301 | The program exits when the user presses the Enter key at the command prompt. |
| 302 | </p> |
| 303 | |
| 304 | <p> |
| 305 | The reader is challenged to add more functionality to the program; for |
| 306 | instance: |
| 307 | <ul> |
| 308 | <li>Implement additional commands, like <code>cp</code>.</li> |
| 309 | <li>Add handling of absolute paths.</li> |
| 310 | <li>Use <a href="tutorial/creation.html#serialization">serialization</a> |
| 311 | to store and retrieve the filesystem state between program runs.</li> |
| 312 | </ul> |
| 313 | </p> |
| 314 | |
| 315 | <h2><a name="example8">Example 8: hashed indices</a></h2> |
| 316 | |
| 317 | <p> |
| 318 | See <a href="../example/hashed.cpp">source code</a>. |
| 319 | </p> |
| 320 | |
| 321 | <p> |
| 322 | Hashed indices can be used as an alternative to ordered indices when |
| 323 | fast lookup is needed and sorting information is of no interest. The |
| 324 | example features a word counter where duplicate entries are checked |
| 325 | by means of a hashed index. Confront the word counting algorithm with |
| 326 | that of <a href="#example5">example 5</a>. |
| 327 | </p> |
| 328 | |
| 329 | <h2><a name="example9">Example 9: serialization and MRU lists</a></h2> |
| 330 | |
| 331 | <p> |
| 332 | See <a href="../example/serialization.cpp">source code</a>. |
| 333 | </p> |
| 334 | |
| 335 | <p> |
| 336 | A typical application of serialization capabilities allows a program to |
| 337 | restore the user context between executions. The example program asks |
| 338 | the user for words and keeps a record of the ten most recently entered |
| 339 | ones, in the current or in previous sessions. The serialized data structure, |
| 340 | sometimes called an <i>MRU (most recently used) list</i>, has some interest |
| 341 | on its own: an MRU list behaves as a regular FIFO queue, with the exception |
| 342 | that, when inserting a preexistent entry, this does not appear twice, but |
| 343 | instead the entry is moved to the front of the list. You can observe this |
| 344 | behavior in many programs featuring a "Recent files" menu command. This |
| 345 | data structure is implemented with <code>multi_index_container</code> by |
| 346 | combining a sequenced index and an index of type <code>hashed_unique</code>. |
| 347 | </p> |
| 348 | |
| 349 | <h2><a name="example10">Example 10: random access indices</a></h2> |
| 350 | |
| 351 | <p> |
| 352 | See <a href="../example/random_access.cpp">source code</a>. |
| 353 | </p> |
| 354 | |
| 355 | <p> |
| 356 | The example resumes the text container introduced in |
| 357 | <a href="#example5">example 5</a> and shows how substituting a random |
| 358 | access index for a sequenced index allows for extra capabilities like |
| 359 | efficient access by position and calculation of the offset of a given |
| 360 | element into the container. |
| 361 | </p> |
| 362 | |
| 363 | <h2><a name="example11">Example 11: index rearrangement</a></h2> |
| 364 | |
| 365 | <p> |
| 366 | See <a href="../example/rearrange.cpp">source code</a>. |
| 367 | </p> |
| 368 | |
| 369 | <p> |
| 370 | There is a relatively common piece of urban lore claiming that |
| 371 | a deck of cards must be shuffled seven times in a row to be perfectly |
| 372 | mixed. The statement derives from the works of mathematician Persi |
| 373 | Diaconis on <i>riffle shuffling</i>: this shuffling |
| 374 | technique involves splitting the deck in two packets roughly the same |
| 375 | size and then dropping the cards from both packets so that they become |
| 376 | interleaved. It has been shown that when repeating this procedure |
| 377 | seven times the statistical distribution of cards is reasonably |
| 378 | close to that associated with a truly random permutation. A measure |
| 379 | of "randomness" can be estimated by counting <i>rising sequences</i>: |
| 380 | consider a permutation of the sequence 1,2, ... , <i>n</i>, a rising sequence |
| 381 | is a maximal chain of consecutive elements <i>m</i>, <i>m+1</i>, ... , <i>m+r</i> |
| 382 | such that they are arranged in ascending order. For instance, the permutation |
| 383 | 125364789 is composed of the two rising sequences 1234 and 56789, |
| 384 | as becomes obvious by displaying the sequence like this, |
| 385 | <span style="vertical-align:sub">1</span><span style="vertical-align:sub">2</span><span style="vertical-align:super">5</span><span style="vertical-align:sub">3</span><span style="vertical-align:super">6</span><span style="vertical-align:sub">4</span><span style="vertical-align:super">7</span><span style="vertical-align:super">8</span><span style="vertical-align:super">9</span>. |
| 386 | The average number of rising sequences in a random permutation of |
| 387 | <i>n</i> elements is (<i>n</i>+1)/2: by contrast, after a single riffle |
| 388 | shuffle of an initially sorted deck of cards, there cannot be more than |
| 389 | two rising sequences. The average number of rising sequences approximates |
| 390 | to (<i>n</i>+1)/2 as the number of consecutive riffle shuffles increases, |
| 391 | with seven shuffles yielding a close result for a 52-card poker deck. |
| 392 | Brad Mann's paper |
| 393 | <a href="http://www.dartmouth.edu/~chance/teaching_aids/books_articles/Mann.pdf">"How |
| 394 | many times should you shuffle a deck of cards?"</a> provides a |
| 395 | rigorous yet very accessible treatment of this subject. |
| 396 | |
| 397 | </p> |
| 398 | |
| 399 | <p> |
| 400 | The example program estimates the average number of rising sequences |
| 401 | in a 52-card deck after repeated riffle shuffling as well as applying |
| 402 | a completely random permutation. The deck is modeled by the following |
| 403 | container: |
| 404 | <blockquote><pre> |
| 405 | <span class=identifier>multi_index_container</span><span class=special><</span> |
| 406 | <span class=keyword>int</span><span class=special>,</span> |
| 407 | <span class=identifier>indexed_by</span><span class=special><</span> |
| 408 | <span class=identifier>random_access</span><span class=special><>,</span> |
| 409 | <span class=identifier>random_access</span><span class=special><></span> |
| 410 | <span class=special>></span> |
| 411 | <span class=special>></span> |
| 412 | </pre></blockquote> |
| 413 | where the first index stores the current arrangement of the deck, while |
| 414 | the second index is used to remember the start position. This representation |
| 415 | allows for an efficient implementation of a rising sequences counting |
| 416 | algorithm in linear time. |
| 417 | <a href="reference/rnd_indices.html#rearrange"><code>rearrange</code></a> |
| 418 | is used to apply to the deck a shuffle performed externally on an |
| 419 | auxiliary data structure. |
| 420 | </p> |
| 421 | |
| 422 | <h2><a name="example12">Example 12: using Boost.Interprocess allocators</a></h2> |
| 423 | |
| 424 | <p> |
| 425 | See <a href="../example/ip_allocator.cpp">source code</a>. |
| 426 | </p> |
| 427 | |
| 428 | <p> |
| 429 | Boost.MultiIndex supports special allocators such as those provided by |
| 430 | <a href="../../interprocess/index.html">Boost.Interprocess</a>, |
| 431 | which allows for <code>multi_index_container</code>s to be placed in shared |
| 432 | memory. The example features a front-end to a small book database |
| 433 | implemented by means of a <code>multi_index_container</code> stored |
| 434 | in a Boost.Interprocess memory mapped file. The reader can verify that several |
| 435 | instances of the program correctly work simultaneously and immediately see |
| 436 | the changes to the database performed by any other instance. |
| 437 | </p> |
| 438 | |
| 439 | <hr> |
| 440 | |
| 441 | <div class="prev_link"><a href="performance.html"><img src="prev.gif" alt="performance" border="0"><br> |
| 442 | Performance |
| 443 | </a></div> |
| 444 | <div class="up_link"><a href="index.html"><img src="up.gif" alt="index" border="0"><br> |
| 445 | Index |
| 446 | </a></div> |
| 447 | <div class="next_link"><a href="tests.html"><img src="next.gif" alt="tests" border="0"><br> |
| 448 | Tests |
| 449 | </a></div><br clear="all" style="clear: all;"> |
| 450 | |
| 451 | <br> |
| 452 | |
| 453 | <p>Revised May 26th 2009</p> |
| 454 | |
| 455 | <p>© Copyright 2003-2009 Joaquín M López Muñoz. |
| 456 | Distributed under the Boost Software |
| 457 | License, Version 1.0. (See accompanying file <a href="../../../LICENSE_1_0.txt"> |
| 458 | LICENSE_1_0.txt</a> or copy at <a href="http://www.boost.org/LICENSE_1_0.txt"> |
| 459 | http://www.boost.org/LICENSE_1_0.txt</a>) |
| 460 | </p> |
| 461 | |
| 462 | </body> |
| 463 | </html> |