projects / ceph.git / blame
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1 | <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> |
| 2 | <html> | |
| 3 | <head> | |
| 4 | <meta content= | |
| 5 | "HTML Tidy for Windows (vers 1st February 2003), see www.w3.org" | |
| 6 | name="generator"> | |
| 7 | <title> | |
| 8 | Quick Start | |
| 9 | </title> | |
| 10 | <meta http-equiv="Content-Type" content="text/html; charset=us-ascii"> | |
| 11 | <link rel="stylesheet" href="theme/style.css" type="text/css"> | |
| 12 | </head> | |
| 13 | <body> | |
| 14 | <table width="100%" border="0" background="theme/bkd2.gif" cellspacing="2"> | |
| 15 | <tr> | |
| 16 | <td width="10"></td> | |
| 17 | <td width="85%"> | |
| 18 | <font size="6" face="Verdana, Arial, Helvetica, sans-serif"><b>Quick | |
| 19 | Start</b></font> | |
| 20 | </td> | |
| 21 | <td width="112"> | |
| 22 | <a href="http://spirit.sf.net"><img src="theme/spirit.gif" | |
| 23 | width="112" height="48" align="right" border="0"></a> | |
| 24 | </td> | |
| 25 | </tr> | |
| 26 | </table><br> | |
| 27 | <table border="0"> | |
| 28 | <tr> | |
| 29 | <td width="10"></td> | |
| 30 | <td width="30"> | |
| 31 | <a href="../index.html"><img src="theme/u_arr.gif" border="0"></a> | |
| 32 | </td> | |
| 33 | <td width="30"> | |
| 34 | <a href="introduction.html"><img src="theme/l_arr.gif" border="0"> | |
| 35 | </a> | |
| 36 | </td> | |
| 37 | <td width="30"> | |
| 38 | <a href="basic_concepts.html"><img src="theme/r_arr.gif" border="0"> | |
| 39 | </a> | |
| 40 | </td> | |
| 41 | </tr> | |
| 42 | </table> | |
| 43 | <h2> | |
| 44 | <b>Why would you want to use Spirit?</b> | |
| 45 | </h2> | |
| 46 | <p> | |
| 47 | Spirit is designed to be a practical parsing tool. At the very least, the | |
| 48 | ability to generate a fully-working parser from a formal EBNF | |
| 49 | specification inlined in C++ significantly reduces development time. | |
| 50 | While it may be practical to use a full-blown, stand-alone parser such as | |
| 51 | YACC or ANTLR when we want to develop a computer language such as C or | |
| 52 | Pascal, it is certainly overkill to bring in the big guns when we wish to | |
| 53 | write extremely small micro-parsers. At that end of the spectrum, | |
| 54 | programmers typically approach the job at hand not as a formal parsing | |
| 55 | task but through ad hoc hacks using primitive tools such as | |
| 56 | <tt>scanf</tt>. True, there are tools such as regular-expression | |
| 57 | libraries (such as <a href= | |
| 58 | "http://www.boost.org/libs/regex/index.html">boost regex</a>) or scanners | |
| 59 | (such as <a href="http://www.boost.org/libs/tokenizer/index.html">boost | |
| 60 | tokenizer</a>), but these tools do not scale well when we need to write | |
| 61 | more elaborate parsers. Attempting to write even a moderately-complex | |
| 62 | parser using these tools leads to code that is hard to understand and | |
| 63 | maintain. | |
| 64 | </p> | |
| 65 | <p> | |
| 66 | One prime objective is to make the tool easy to use. When one thinks of a | |
| 67 | parser generator, the usual reaction is "it must be big and complex with | |
| 68 | a steep learning curve." Not so. Spirit is designed to be fully scalable. | |
| 69 | The framework is structured in layers. This permits learning on an | |
| 70 | as-needed basis, after only learning the minimal core and basic concepts. | |
| 71 | </p> | |
| 72 | <p> | |
| 73 | For development simplicity and ease in deployment, the entire framework | |
| 74 | consists of only header files, with no libraries to link against or | |
| 75 | build. Just put the spirit distribution in your include path, compile and | |
| 76 | run. Code size? -very tight. In the quick start example that we shall | |
| 77 | present in a short while, the code size is dominated by the instantiation | |
| 78 | of the <tt>std::vector</tt> and <tt>std::iostream</tt>. | |
| 79 | </p> | |
| 80 | <h2> | |
| 81 | <b>Trivial Example #1</b></h2> | |
| 82 | <p>Create a parser that will parse | |
| 83 | a floating-point number. | |
| 84 | </p> | |
| 85 | <pre><code><font color="#000000"> </font></code><span class="identifier">real_p</span> | |
| 86 | </pre> | |
| 87 | <p> | |
| 88 | (You've got to admit, that's trivial!) The above code actually generates | |
| 89 | a Spirit <tt>real_parser</tt> (a built-in parser) which parses a floating | |
| 90 | point number. Take note that parsers that are meant to be used directly | |
| 91 | by the user end with "<tt>_p</tt>" in their names as a Spirit convention. | |
| 92 | Spirit has many pre-defined parsers and consistent naming conventions | |
| 93 | help you keep from going insane! | |
| 94 | </p> | |
| 95 | <h2> | |
| 96 | <b>Trivial Example #2</b></h2> | |
| 97 | <p> | |
| 98 | Create a parser that will accept a line consisting of two floating-point | |
| 99 | numbers. | |
| 100 | </p> | |
| 101 | ||
| 102 | <pre><code><font color="#000000"> </font></code><code><span class= | |
| 103 | "identifier">real_p</span> <span class= | |
| 104 | "special">>></span> <span class="identifier">real_p</span></code> | |
| 105 | </pre> | |
| 106 | <p> | |
| 107 | Here you see the familiar floating-point numeric parser | |
| 108 | <code><tt>real_p</tt></code> used twice, once for each number. What's | |
| 109 | that <tt class="operators">>></tt> operator doing in there? Well, | |
| 110 | they had to be separated by something, and this was chosen as the | |
| 111 | "followed by" sequence operator. The above program creates a parser from | |
| 112 | two simpler parsers, glueing them together with the sequence operator. | |
| 113 | The result is a parser that is a composition of smaller parsers. | |
| 114 | Whitespace between numbers can implicitly be consumed depending on how | |
| 115 | the parser is invoked (see below). | |
| 116 | </p> | |
| 117 | <p> | |
| 118 | Note: when we combine parsers, we end up with a "bigger" parser, But it's | |
| 119 | still a parser. Parsers can get bigger and bigger, nesting more and more, | |
| 120 | but whenever you glue two parsers together, you end up with one bigger | |
| 121 | parser. This is an important concept. | |
| 122 | </p> | |
| 123 | <h2> | |
| 124 | <b>Trivial Example #3</b></h2> | |
| 125 | <p> | |
| 126 | Create a parser that will accept an arbitrary number of floating-point | |
| 127 | numbers. (Arbitrary means anything from zero to infinity) | |
| 128 | </p> | |
| 129 | ||
| 130 | <pre><code><font color="#000000"> </font></code><code><span class= | |
| 131 | "special">*</span><span class="identifier">real_p</span></code> | |
| 132 | </pre> | |
| 133 | <p> | |
| 134 | This is like a regular-expression Kleene Star, though the syntax might | |
| 135 | look a bit odd for a C++ programmer not used to seeing the <tt class= | |
| 136 | "operators">*</tt> operator overloaded like this. Actually, if you know | |
| 137 | regular expressions it may look odd too since the star is <b>before</b> | |
| 138 | the expression it modifies. C'est la vie. Blame it on the fact that we | |
| 139 | must work with the syntax rules of C++. | |
| 140 | </p> | |
| 141 | <p> | |
| 142 | Any expression that evaluates to a parser may be used with the Kleene | |
| 143 | Star. Keep in mind, though, that due to C++ operator precedence rules you | |
| 144 | may need to put the expression in parentheses for complex expressions. | |
| 145 | The Kleene Star is also known as a Kleene Closure, but we call it the | |
| 146 | Star in most places. | |
| 147 | </p> | |
| 148 | <h3> | |
| 149 | <b><a name="list_of_numbers"></a> Example #4 [ A Just Slightly Less Trivial Example</b> | |
| 150 | ] </h3> | |
| 151 | <p> | |
| 152 | This example will create a parser that accepts a comma-delimited list of numbers and put the numbers in a vector. | |
| 153 | </p> | |
| 154 | <h4><strong> Step 1. Create the parser</strong></h4> | |
| 155 | <pre><code><font color="#000000"> </font></code><code><span class= | |
| 156 | "identifier">real_p</span> <span class= | |
| 157 | "special">>></span> <span class="special">*(</span><span class= | |
| 158 | "identifier">ch_p</span><span class="special">(</span><span class= | |
| 159 | "literal">','</span><span class="special">)</span> <span class= | |
| 160 | "special">>></span> <span class= | |
| 161 | "identifier">real_p</span><span class="special">)</span></code> | |
| 162 | </pre> | |
| 163 | <p> | |
| 164 | Notice <tt>ch_p(',')</tt>. It is a literal character parser that can | |
| 165 | recognize the comma <tt>','</tt>. In this case, the Kleene Star is | |
| 166 | modifying a more complex parser, namely, the one generated by the | |
| 167 | expression: | |
| 168 | </p> | |
| 169 | ||
| 170 | <pre><code><font color="#000000"> </font></code><code><span class= | |
| 171 | "special">(</span><span class="identifier">ch_p</span><span class= | |
| 172 | "special">(</span><span class="literal">','</span><span class= | |
| 173 | "special">)</span> <span class="special">>></span> <span class= | |
| 174 | "identifier">real_p</span><span class="special">)</span></code> | |
| 175 | </pre> | |
| 176 | <p> | |
| 177 | Note that this is a case where the parentheses are necessary. The Kleene | |
| 178 | star encloses the complete expression above. | |
| 179 | </p> | |
| 180 | <h4> | |
| 181 | <b><strong>Step 2. </strong>Using a Parser (now that it's created)</b></h4> | |
| 182 | <p> | |
| 183 | Now that we have created a parser, how do we use it? Like the result of | |
| 184 | any C++ temporary object, we can either store it in a variable, or call | |
| 185 | functions directly on it. | |
| 186 | </p> | |
| 187 | <p> | |
| 188 | We'll gloss over some low-level C++ details and just get to the good | |
| 189 | stuff. | |
| 190 | </p> | |
| 191 | <p> | |
| 192 | If <b><tt>r</tt></b> is a rule (don't worry about what rules exactly are | |
| 193 | for now. This will be discussed later. Suffice it to say that the rule is | |
| 194 | a placeholder variable that can hold a parser), then we store the parser | |
| 195 | as a rule like this: | |
| 196 | </p> | |
| 197 | ||
| 198 | <pre><code><font color="#000000"> </font></code><code><font color="#000000"><span class= | |
| 199 | "identifier">r</span> <span class="special">=</span> <span class= | |
| 200 | "identifier">real_p</span> <span class= | |
| 201 | "special">>> *(</span><span class= | |
| 202 | "identifier">ch_p</span><span class="special">(</span><span class= | |
| 203 | "literal">','</span><span class="special">) >></span> <span class= | |
| 204 | "identifier">real_p</span><span class="special">);</span></font></code> | |
| 205 | </pre> | |
| 206 | <p> | |
| 207 | Not too exciting, just an assignment like any other C++ expression you've | |
| 208 | used for years. The cool thing about storing a parser in a rule is this: | |
| 209 | rules are parsers, and now you can refer to it <b>by name</b>. (In this | |
| 210 | case the name is <tt><b>r</b></tt>). Notice that this is now a full | |
| 211 | assignment expression, thus we terminate it with a semicolon, | |
| 212 | "<tt>;</tt>". | |
| 213 | </p> | |
| 214 | <p> | |
| 215 | That's it. We're done with defining the parser. So the next step is now | |
| 216 | invoking this parser to do its work. There are a couple of ways to do | |
| 217 | this. For now, we shall use the free <tt>parse</tt> function that takes | |
| 218 | in a <tt>char const*</tt>. The function accepts three arguments: | |
| 219 | </p> | |
| 220 | <blockquote> | |
| 221 | <p> | |
| 222 | <img src="theme/bullet.gif" width="12" height="12"> The null-terminated | |
| 223 | <tt>const char*</tt> input<br> | |
| 224 | <img src="theme/bullet.gif" width="12" height="12"> The parser | |
| 225 | object<br> | |
| 226 | <img src="theme/bullet.gif" width="12" height="12"> Another parser | |
| 227 | called the <b>skip parser</b> | |
| 228 | </p> | |
| 229 | </blockquote> | |
| 230 | <p> | |
| 231 | In our example, we wish to skip spaces and tabs. Another parser named | |
| 232 | <tt>space_p</tt> is included in Spirit's repertoire of predefined | |
| 233 | parsers. It is a very simple parser that simply recognizes whitespace. We | |
| 234 | shall use <tt>space_p</tt> as our skip parser. The skip parser is the one | |
| 235 | responsible for skipping characters in between parser elements such as | |
| 236 | the <tt>real_p</tt> and the <tt>ch_p</tt>. | |
| 237 | </p> | |
| 238 | <p> | |
| 239 | Ok, so now let's parse! | |
| 240 | </p> | |
| 241 | ||
| 242 | <pre><code><font color="#000000"> </font></code><code><font color="#000000"><span class= | |
| 243 | "identifier">r</span> <span class="special">=</span> <span class= | |
| 244 | "identifier">real_p</span> <span class= | |
| 245 | "special">>></span> <span class="special">*(</span><span class= | |
| 246 | "identifier">ch_p</span><span class="special">(</span><span class= | |
| 247 | "literal">','</span><span class="special">)</span> <span class= | |
| 248 | "special">>></span> <span class= | |
| 249 | "identifier">real_p</span><span class="special">); | |
| 250 | </span> <span class="identifier"> parse</span><span class= | |
| 251 | "special">(</span><span class="identifier">str</span><span class= | |
| 252 | "special">,</span> <span class="identifier">r</span><span class= | |
| 253 | "special">,</span> <span class="identifier">space_p</span><span class= | |
| 254 | "special">)</span> <span class= | |
| 255 | "comment">// Not a full statement yet, patience...</span></font></code> | |
| 256 | </pre> | |
| 257 | <p> | |
| 258 | The parse function returns an object (called <tt>parse_info</tt>) that | |
| 259 | holds, among other things, the result of the parse. In this example, we | |
| 260 | need to know: | |
| 261 | </p> | |
| 262 | <blockquote> | |
| 263 | <p> | |
| 264 | <img src="theme/bullet.gif" width="12" height="12"> Did the parser | |
| 265 | successfully recognize the input <tt>str</tt>?<br> | |
| 266 | <img src="theme/bullet.gif" width="12" height="12"> Did the parser | |
| 267 | <b>fully</b> parse and consume the input up to its end? | |
| 268 | </p> | |
| 269 | </blockquote> | |
| 270 | <p> | |
| 271 | To get a complete picture of what we have so far, let us also wrap this | |
| 272 | parser inside a function: | |
| 273 | </p> | |
| 274 | ||
| 275 | <pre><code><font color="#000000"> </font></code><code><font color="#000000"><span class= | |
| 276 | "keyword">bool | |
| 277 | </span> <span class="identifier"> parse_numbers</span><span class= | |
| 278 | "special">(</span><span class="keyword">char</span> <span class= | |
| 279 | "keyword">const</span><span class="special">*</span> <span class= | |
| 280 | "identifier">str</span><span class="special">) | |
| 281 | { | |
| 282 | </span> <span class="keyword"> return</span> <span class= | |
| 283 | "identifier">parse</span><span class="special">(</span><span class= | |
| 284 | "identifier">str</span><span class="special">,</span> <span class= | |
| 285 | "identifier">real_p</span> <span class= | |
| 286 | "special">>></span> <span class="special">*(</span><span class= | |
| 287 | "literal">','</span> <span class="special">>></span> <span class= | |
| 288 | "identifier">real_p</span><span class="special">),</span> <span class= | |
| 289 | "identifier">space_p</span><span class="special">).</span><span class= | |
| 290 | "identifier">full</span><span class="special">; | |
| 291 | }</span></font></code> | |
| 292 | </pre> | |
| 293 | <p> | |
| 294 | Note in this case we dropped the named rule and inlined the parser | |
| 295 | directly in the call to parse. Upon calling parse, the expression | |
| 296 | evaluates into a temporary, unnamed parser which is passed into the | |
| 297 | parse() function, used, and then destroyed. | |
| 298 | </p> | |
| 299 | <table border="0" width="80%" align="center"> | |
| 300 | <tr> | |
| 301 | <td class="note_box"> | |
| 302 | <img src="theme/note.gif" width="16" height="16"><b>char and wchar_t | |
| 303 | operands</b><br> | |
| 304 | <br> | |
| 305 | The careful reader may notice that the parser expression has | |
| 306 | <tt class="quotes">','</tt> instead of <tt>ch_p(',')</tt> as the | |
| 307 | previous examples did. This is ok due to C++ syntax rules of | |
| 308 | conversion. There are <tt>>></tt> operators that are overloaded | |
| 309 | to accept a <tt>char</tt> or <tt>wchar_t</tt> argument on its left or | |
| 310 | right (but not both). An operator may be overloaded if at least one | |
| 311 | of its parameters is a user-defined type. In this case, the | |
| 312 | <tt>real_p</tt> is the 2nd argument to <tt>operator<span class= | |
| 313 | "operators">>></span></tt>, and so the proper overload of | |
| 314 | <tt class="operators">>></tt> is used, converting | |
| 315 | <tt class="quotes">','</tt> into a character literal parser.<br> | |
| 316 | <br> | |
| 317 | The problem with omiting the <tt>ch_p</tt> call should be obvious: | |
| 318 | <tt>'a' >> 'b'</tt> is <b>not</b> a spirit parser, it is a | |
| 319 | numeric expression, right-shifting the ASCII (or another encoding) | |
| 320 | value of <tt class="quotes">'a'</tt> by the ASCII value of | |
| 321 | <tt class="quotes">'b'</tt>. However, both <tt>ch_p('a') >> | |
| 322 | 'b'</tt> and <tt>'a' >> ch_p('b')</tt> are Spirit sequence | |
| 323 | parsers for the letter <tt class="quotes">'a'</tt> followed by | |
| 324 | <tt class="quotes">'b'</tt>. You'll get used to it, sooner or | |
| 325 | later. | |
| 326 | </td> | |
| 327 | </tr> | |
| 328 | </table> | |
| 329 | <p> | |
| 330 | Take note that the object returned from the parse function has a member | |
| 331 | called <tt>full</tt> which returns true if both of our requirements above | |
| 332 | are met (i.e. the parser fully parsed the input). | |
| 333 | </p> | |
| 334 | <h4> | |
| 335 | <b> Step 3. Semantic Actions</b></h4> | |
| 336 | <p> | |
| 337 | Our parser above is really nothing but a recognizer. It answers the | |
| 338 | question <i class="quotes">"did the input match our grammar?"</i>, but it | |
| 339 | does not remember any data, nor does it perform any side effects. | |
| 340 | Remember: we want to put the parsed numbers into a vector. This is done | |
| 341 | in an <b>action</b> that is linked to a particular parser. For example, | |
| 342 | whenever we parse a real number, we wish to store the parsed number after | |
| 343 | a successful match. We now wish to extract information from the parser. | |
| 344 | Semantic actions do this. Semantic actions may be attached to any point | |
| 345 | in the grammar specification. These actions are C++ functions or functors | |
| 346 | that are called whenever a part of the parser successfully recognizes a | |
| 347 | portion of the input. Say you have a parser <b>P</b>, and a C++ function | |
| 348 | <b>F</b>, you can make the parser call <b>F</b> whenever it matches an | |
| 349 | input by attaching <b>F</b>: | |
| 350 | </p> | |
| 351 | ||
| 352 | <pre><code><font color="#000000"> </font></code><code><font color="#000000"><span class= | |
| 353 | "identifier">P</span><span class="special">[&</span><span class= | |
| 354 | "identifier">F</span><span class="special">]</span></font></code> | |
| 355 | </pre> | |
| 356 | <p> | |
| 357 | Or if <b>F</b> is a function object (a functor): | |
| 358 | </p> | |
| 359 | ||
| 360 | <pre><code><font color="#000000"> </font></code><code><font color="#000000"><span class= | |
| 361 | "identifier">P</span><span class="special">[</span><span class= | |
| 362 | "identifier">F</span><span class="special">]</span></font></code> | |
| 363 | </pre> | |
| 364 | <p> | |
| 365 | The function/functor signature depends on the type of the parser to which | |
| 366 | it is attached. The parser <tt>real_p</tt> passes a single argument: the | |
| 367 | parsed number. Thus, if we were to attach a function <b>F</b> to | |
| 368 | <tt>real_p</tt>, we need <b>F</b> to be declared as: | |
| 369 | </p> | |
| 370 | ||
| 371 | <pre><code> </code><code><span class= | |
| 372 | "keyword">void</span> <span class="identifier">F</span><span class= | |
| 373 | "special">(</span><span class="keyword">double</span> <span class= | |
| 374 | "identifier">n</span><span class="special">);</span></code></pre> | |
| 375 | <p> | |
| 376 | For our example however, again, we can take advantage of some predefined | |
| 377 | semantic functors and functor generators (<img src="theme/lens.gif" | |
| 378 | width="15" height="16"> A functor generator is a function that returns | |
| 379 | a functor). For our purpose, Spirit has a functor generator | |
| 380 | <tt>push_back_a(c)</tt>. In brief, this semantic action, when called, | |
| 381 | <b>appends</b> the parsed value it receives from the parser it is | |
| 382 | attached to, to the container <tt>c</tt>. | |
| 383 | </p> | |
| 384 | <p> | |
| 385 | Finally, here is our complete comma-separated list parser: | |
| 386 | </p> | |
| 387 | ||
| 388 | <pre><code><font color="#000000"> </font></code><code><font color="#000000"><span class= | |
| 389 | "keyword">bool | |
| 390 | </span> <span class="identifier">parse_numbers</span><span class= | |
| 391 | "special">(</span><span class="keyword">char</span> <span class= | |
| 392 | "keyword">const</span><span class="special">*</span> <span class= | |
| 393 | "identifier">str</span><span class="special">,</span> <span class= | |
| 394 | "identifier">vector</span><span class="special"><</span><span class= | |
| 395 | "keyword">double</span><span class= | |
| 396 | "special">>&</span> <span class="identifier">v</span><span class= | |
| 397 | "special">) | |
| 398 | { | |
| 399 | </span> <span class="keyword">return</span> <span class= | |
| 400 | "identifier">parse</span><span class="special">(</span><span class= | |
| 401 | "identifier">str</span><span class="special">, | |
| 402 | ||
| 403 | </span> <span class="comment"> // Begin grammar | |
| 404 | </span> <span class="special"> ( | |
| 405 | </span> <span class="identifier">real_p</span><span class= | |
| 406 | "special">[</span><span class="identifier">push_back_a</span><span class= | |
| 407 | "special">(</span><span class="identifier">v</span><span class= | |
| 408 | "special">)]</span> <span class="special">>></span> <span class= | |
| 409 | "special">*(</span><span class="literal">','</span> <span class= | |
| 410 | "special">>></span> <span class= | |
| 411 | "identifier">real_p</span><span class="special">[</span><span class= | |
| 412 | "identifier">push_back_a</span><span class="special">(</span><span class= | |
| 413 | "identifier">v</span><span class="special">)]) | |
| 414 | ) | |
| 415 | </span> <span class="special"> , | |
| 416 | </span> <span class="comment"> // End grammar | |
| 417 | ||
| 418 | </span> <span class="identifier"> space_p</span><span class= | |
| 419 | "special">).</span><span class="identifier">full</span><span class="special">; | |
| 420 | }</span></font></code> | |
| 421 | </pre> | |
| 422 | <p> | |
| 423 | This is the same parser as above. This time with appropriate semantic | |
| 424 | actions attached to strategic places to extract the parsed numbers and | |
| 425 | stuff them in the vector <tt>v</tt>. The parse_numbers function returns | |
| 426 | true when successful. | |
| 427 | </p> | |
| 428 | <p> | |
| 429 | <img src="theme/lens.gif" width="15" height="16"> The full source code | |
| 430 | can be <a href="../example/fundamental/number_list.cpp">viewed here</a>. | |
| 431 | This is part of the Spirit distribution. | |
| 432 | </p> | |
| 433 | <table border="0"> | |
| 434 | <tr> | |
| 435 | <td width="10"></td> | |
| 436 | <td width="30"> | |
| 437 | <a href="../index.html"><img src="theme/u_arr.gif" border="0"></a> | |
| 438 | </td> | |
| 439 | <td width="30"> | |
| 440 | <a href="introduction.html"><img src="theme/l_arr.gif" border="0"> | |
| 441 | </a> | |
| 442 | </td> | |
| 443 | <td width="30"> | |
| 444 | <a href="basic_concepts.html"><img src="theme/r_arr.gif" border="0"> | |
| 445 | </a> | |
| 446 | </td> | |
| 447 | </tr> | |
| 448 | </table><br> | |
| 449 | <hr size="1"> | |
| 450 | <p class="copyright"> | |
| 451 | Copyright © 1998-2003 Joel de Guzman<br> | |
| 452 | Copyright © 2002 Chris Uzdavinis<br> | |
| 453 | <br> | |
| 454 | <font size="2">Use, modification and distribution is subject to the | |
| 455 | Boost Software License, Version 1.0. (See accompanying file | |
| 456 | LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)</font> | |
| 457 | </p> | |
| 458 | <blockquote> | |
| 459 | ||
| 460 | </blockquote> | |
| 461 | </body> | |
| 462 | </html> |