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  26 <div class="titlepage"><div><div><h5 class="title">
  27 <a name="spirit.qi.reference.char.char"></a><a class="link" href="char.html" title="Character Parser (char_, lit)">Character Parser (<code class="computeroutput"><span class="identifier">char_</span></code>, <code class="computeroutput"><span class="identifier">lit</span></code>)</a>
  28 </h5></div></div></div>
  29 <h6>
  30 <a name="spirit.qi.reference.char.char.h0"></a>
  31             <span><a name="spirit.qi.reference.char.char.description"></a></span><a class="link" href="char.html#spirit.qi.reference.char.char.description">Description</a>
  32           </h6>
  33 <p>
  34             The <code class="computeroutput"><span class="identifier">char_</span></code> parser matches
  35             single characters. The <code class="computeroutput"><span class="identifier">char_</span></code>
  36             parser has an associated <a class="link" href="../basics.html#spirit.qi.reference.basics.character_encoding_namespace">Character
  37             Encoding Namespace</a>. This is needed when doing basic operations
  38             such as inhibiting case sensitivity and dealing with character ranges.
  39           </p>
  40 <p>
  41             There are various forms of <code class="computeroutput"><span class="identifier">char_</span></code>.
  42           </p>
  43 <h6>
  44 <a name="spirit.qi.reference.char.char.h1"></a>
  45             <span><a name="spirit.qi.reference.char.char.char_"></a></span><a class="link" href="char.html#spirit.qi.reference.char.char.char_">char_</a>
  46           </h6>
  47 <p>
  48             The no argument form of <code class="computeroutput"><span class="identifier">char_</span></code>
  49             matches any character in the associated <a class="link" href="../basics.html#spirit.qi.reference.basics.character_encoding_namespace">Character
  50             Encoding Namespace</a>.
  51           </p>
  52 <pre class="programlisting"><span class="identifier">char_</span>               <span class="comment">// matches any character</span>
  53 </pre>
  54 <h6>
  55 <a name="spirit.qi.reference.char.char.h2"></a>
  56             <span><a name="spirit.qi.reference.char.char.char__ch_"></a></span><a class="link" href="char.html#spirit.qi.reference.char.char.char__ch_">char_(ch)</a>
  57           </h6>
  58 <p>
  59             The single argument form of <code class="computeroutput"><span class="identifier">char_</span></code>
  60             (with a character argument) matches the supplied character.
  61           </p>
  62 <pre class="programlisting"><span class="identifier">char_</span><span class="special">(</span><span class="char">'x'</span><span class="special">)</span>          <span class="comment">// matches 'x'</span>
  63 <span class="identifier">char_</span><span class="special">(</span><span class="identifier">L</span><span class="char">'x'</span><span class="special">)</span>         <span class="comment">// matches L'x'</span>
  64 <span class="identifier">char_</span><span class="special">(</span><span class="identifier">x</span><span class="special">)</span>            <span class="comment">// matches x (a char)</span>
  65 </pre>
  66 <h6>
  67 <a name="spirit.qi.reference.char.char.h3"></a>
  68             <span><a name="spirit.qi.reference.char.char.char__first__last_"></a></span><a class="link" href="char.html#spirit.qi.reference.char.char.char__first__last_">char_(first,
  69             last)</a>
  70           </h6>
  71 <p>
  72             <code class="computeroutput"><span class="identifier">char_</span></code> with two arguments,
  73             matches a range of characters.
  74           </p>
  75 <pre class="programlisting"><span class="identifier">char_</span><span class="special">(</span><span class="char">'a'</span><span class="special">,</span><span class="char">'z'</span><span class="special">)</span>      <span class="comment">// alphabetic characters</span>
  76 <span class="identifier">char_</span><span class="special">(</span><span class="identifier">L</span><span class="char">'0'</span><span class="special">,</span><span class="identifier">L</span><span class="char">'9'</span><span class="special">)</span>    <span class="comment">// digits</span>
  77 </pre>
  78 <p>
  79             A range of characters is created from a low-high character pair. Such
  80             a parser matches a single character that is in the range, including both
  81             endpoints. Note, the first character must be <span class="emphasis"><em>before</em></span>
  82             the second, according to the underlying <a class="link" href="../basics.html#spirit.qi.reference.basics.character_encoding_namespace">Character
  83             Encoding Namespace</a>.
  84           </p>
  85 <p>
  86             Character mapping is inherently platform dependent. It is not guaranteed
  87             in the standard for example that <code class="computeroutput"><span class="char">'A'</span>
  88             <span class="special">&lt;</span> <span class="char">'Z'</span></code>,
  89             that is why in Spirit2, we purposely attach a specific <a class="link" href="../basics.html#spirit.qi.reference.basics.character_encoding_namespace">Character
  90             Encoding Namespace</a> (such as ASCII, ISO-8859-1) to the <code class="computeroutput"><span class="identifier">char_</span></code> parser to eliminate such ambiguities.
  91           </p>
  92 <div class="note"><table border="0" summary="Note">
  93 <tr>
  94 <td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="../../../../images/note.png"></td>
  95 <th align="left">Note</th>
  96 </tr>
  97 <tr><td align="left" valign="top">
  98 <p>
  99               <span class="bold"><strong>Sparse bit vectors</strong></span>
 100             </p>
 101 <p>
 102               To accommodate 16/32 and 64 bit characters, the char-set statically
 103               switches from a <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">bitset</span></code>
 104               implementation when the character type is not greater than 8 bits,
 105               to a sparse bit/boolean set which uses a sorted vector of disjoint
 106               ranges (<code class="computeroutput"><span class="identifier">range_run</span></code>).
 107               The set is constructed from ranges such that adjacent or overlapping
 108               ranges are coalesced.
 109             </p>
 110 <p>
 111               <code class="computeroutput"><span class="identifier">range_runs</span></code> are very
 112               space-economical in situations where there are lots of ranges and a
 113               few individual disjoint values. Searching is O(log n) where n is the
 114               number of ranges.
 115             </p>
 116 </td></tr>
 117 </table></div>
 118 <h6>
 119 <a name="spirit.qi.reference.char.char.h4"></a>
 120             <span><a name="spirit.qi.reference.char.char.char__def_"></a></span><a class="link" href="char.html#spirit.qi.reference.char.char.char__def_">char_(def)</a>
 121           </h6>
 122 <p>
 123             Lastly, when given a string (a plain C string, a <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_string</span></code>,
 124             etc.), the string is regarded as a char-set definition string following
 125             a syntax that resembles posix style regular expression character sets
 126             (except that double quotes delimit the set elements instead of square
 127             brackets and there is no special negation ^ character). Examples:
 128           </p>
 129 <pre class="programlisting"><span class="identifier">char_</span><span class="special">(</span><span class="string">"a-zA-Z"</span><span class="special">)</span>     <span class="comment">// alphabetic characters</span>
 130 <span class="identifier">char_</span><span class="special">(</span><span class="string">"0-9a-fA-F"</span><span class="special">)</span>  <span class="comment">// hexadecimal characters</span>
 131 <span class="identifier">char_</span><span class="special">(</span><span class="string">"actgACTG"</span><span class="special">)</span>   <span class="comment">// DNA identifiers</span>
 132 <span class="identifier">char_</span><span class="special">(</span><span class="string">"\x7f\x7e"</span><span class="special">)</span>   <span class="comment">// Hexadecimal 0x7F and 0x7E</span>
 133 </pre>
 134 <h6>
 135 <a name="spirit.qi.reference.char.char.h5"></a>
 136             <span><a name="spirit.qi.reference.char.char.lit_ch_"></a></span><a class="link" href="char.html#spirit.qi.reference.char.char.lit_ch_">lit(ch)</a>
 137           </h6>
 138 <p>
 139             <code class="computeroutput"><span class="identifier">lit</span></code>, when passed a single
 140             character, behaves like the single argument <code class="computeroutput"><span class="identifier">char_</span></code>
 141             except that <code class="computeroutput"><span class="identifier">lit</span></code> does
 142             not synthesize an attribute. A plain <code class="computeroutput"><span class="keyword">char</span></code>
 143             or <code class="computeroutput"><span class="keyword">wchar_t</span></code> is equivalent
 144             to a <code class="computeroutput"><span class="identifier">lit</span></code>.
 145           </p>
 146 <div class="note"><table border="0" summary="Note">
 147 <tr>
 148 <td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="../../../../images/note.png"></td>
 149 <th align="left">Note</th>
 150 </tr>
 151 <tr><td align="left" valign="top"><p>
 152               <code class="computeroutput"><span class="identifier">lit</span></code> is reused by both
 153               the <a class="link" href="../string/string.html" title="String Parsers (string, lit)">string parsers</a>
 154               and the char parsers. In general, a char parser is created when you
 155               pass in a character and a string parser is created when you pass in
 156               a string. The exception is when you pass a single element literal string,
 157               e.g. <code class="computeroutput"><span class="identifier">lit</span><span class="special">(</span><span class="string">"x"</span><span class="special">)</span></code>.
 158               In this case, we optimize this to create a char parser instead of a
 159               string parser.
 160             </p></td></tr>
 161 </table></div>
 162 <p>
 163             Examples:
 164           </p>
 165 <pre class="programlisting"><span class="char">'x'</span>
 166 <span class="identifier">lit</span><span class="special">(</span><span class="char">'x'</span><span class="special">)</span>
 167 <span class="identifier">lit</span><span class="special">(</span><span class="identifier">L</span><span class="char">'x'</span><span class="special">)</span>
 168 <span class="identifier">lit</span><span class="special">(</span><span class="identifier">c</span><span class="special">)</span> <span class="comment">// c is a char</span>
 169 </pre>
 170 <h6>
 171 <a name="spirit.qi.reference.char.char.h6"></a>
 172             <span><a name="spirit.qi.reference.char.char.header"></a></span><a class="link" href="char.html#spirit.qi.reference.char.char.header">Header</a>
 173           </h6>
 174 <pre class="programlisting"><span class="comment">// forwards to &lt;boost/spirit/home/qi/char/char.hpp&gt;</span>
 175 <span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">spirit</span><span class="special">/</span><span class="identifier">include</span><span class="special">/</span><span class="identifier">qi_char_</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
 176 </pre>
 177 <p>
 178             Also, see <a class="link" href="../../../structure/include.html" title="Include">Include Structure</a>.
 179           </p>
 180 <h6>
 181 <a name="spirit.qi.reference.char.char.h7"></a>
 182             <span><a name="spirit.qi.reference.char.char.namespace"></a></span><a class="link" href="char.html#spirit.qi.reference.char.char.namespace">Namespace</a>
 183           </h6>
 184 <div class="informaltable"><table class="table">
 185 <colgroup><col></colgroup>
 186 <thead><tr><th>
 187                     <p>
 188                       Name
 189                     </p>
 190                   </th></tr></thead>
 191 <tbody>
 192 <tr><td>
 193                     <p>
 194                       <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">spirit</span><span class="special">::</span><span class="identifier">lit</span> <span class="comment">// alias:
 195                       boost::spirit::qi::lit</span></code>
 196                     </p>
 197                   </td></tr>
 198 <tr><td>
 199                     <p>
 200                       <code class="computeroutput"><span class="identifier">ns</span><span class="special">::</span><span class="identifier">char_</span></code>
 201                     </p>
 202                   </td></tr>
 203 </tbody>
 204 </table></div>
 205 <p>
 206             In the table above, <code class="computeroutput"><span class="identifier">ns</span></code>
 207             represents a <a class="link" href="../basics.html#spirit.qi.reference.basics.character_encoding_namespace">Character
 208             Encoding Namespace</a>.
 209           </p>
 210 <h6>
 211 <a name="spirit.qi.reference.char.char.h8"></a>
 212             <span><a name="spirit.qi.reference.char.char.model_of"></a></span><a class="link" href="char.html#spirit.qi.reference.char.char.model_of">Model
 213             of</a>
 214           </h6>
 215 <div class="blockquote"><blockquote class="blockquote"><p>
 216               <a class="link" href="../parser_concepts/primitiveparser.html" title="PrimitiveParser"><code class="computeroutput"><span class="identifier">PrimitiveParser</span></code></a>
 217             </p></blockquote></div>
 218 <div class="variablelist">
 219 <p class="title"><b>Notation</b></p>
 220 <dl>
 221 <dt><span class="term"><code class="computeroutput"><span class="identifier">c</span></code>, <code class="computeroutput"><span class="identifier">f</span></code>, <code class="computeroutput"><span class="identifier">l</span></code></span></dt>
 222 <dd><p>
 223                   A literal char, e.g. <code class="computeroutput"><span class="char">'x'</span></code>,
 224                   <code class="computeroutput"><span class="identifier">L</span><span class="char">'x'</span></code>
 225                   or anything that can be converted to a <code class="computeroutput"><span class="keyword">char</span></code>
 226                   or <code class="computeroutput"><span class="keyword">wchar_t</span></code>, or a
 227                   <a class="link" href="../basics.html#spirit.qi.reference.basics.lazy_argument">Lazy Argument</a>
 228                   that evaluates to anything that can be converted to a <code class="computeroutput"><span class="keyword">char</span></code> or <code class="computeroutput"><span class="keyword">wchar_t</span></code>.
 229                 </p></dd>
 230 <dt><span class="term"><code class="computeroutput"><span class="identifier">ns</span></code></span></dt>
 231 <dd><p>
 232                   A <a class="link" href="../basics.html#spirit.qi.reference.basics.character_encoding_namespace">Character
 233                   Encoding Namespace</a>.
 234                 </p></dd>
 235 <dt><span class="term"><code class="computeroutput"><span class="identifier">cs</span></code></span></dt>
 236 <dd><p>
 237                   A <a class="link" href="../basics.html#spirit.qi.reference.basics.string">String</a>
 238                   or a <a class="link" href="../basics.html#spirit.qi.reference.basics.lazy_argument">Lazy
 239                   Argument</a> that evaluates to a <a class="link" href="../basics.html#spirit.qi.reference.basics.string">String</a>
 240                   that specifies a char-set definition string following a syntax
 241                   that resembles posix style regular expression character sets (except
 242                   the square brackets and the negation <code class="computeroutput"><span class="special">^</span></code>
 243                   character).
 244                 </p></dd>
 245 <dt><span class="term"><code class="computeroutput"><span class="identifier">cp</span></code></span></dt>
 246 <dd><p>
 247                   A char parser, a char range parser or a char set parser.
 248                 </p></dd>
 249 </dl>
 250 </div>
 251 <h6>
 252 <a name="spirit.qi.reference.char.char.h9"></a>
 253             <span><a name="spirit.qi.reference.char.char.expression_semantics"></a></span><a class="link" href="char.html#spirit.qi.reference.char.char.expression_semantics">Expression
 254             Semantics</a>
 255           </h6>
 256 <p>
 257             Semantics of an expression is defined only where it differs from, or
 258             is not defined in <a class="link" href="../parser_concepts/primitiveparser.html" title="PrimitiveParser"><code class="computeroutput"><span class="identifier">PrimitiveParser</span></code></a>.
 259           </p>
 260 <div class="informaltable"><table class="table">
 261 <colgroup>
 262 <col>
 263 <col>
 264 </colgroup>
 265 <thead><tr>
 266 <th>
 267                     <p>
 268                       Expression
 269                     </p>
 270                   </th>
 271 <th>
 272                     <p>
 273                       Semantics
 274                     </p>
 275                   </th>
 276 </tr></thead>
 277 <tbody>
 278 <tr>
 279 <td>
 280                     <p>
 281                       <code class="computeroutput"><span class="identifier">c</span></code>
 282                     </p>
 283                   </td>
 284 <td>
 285                     <p>
 286                       Create char parser from a char, <code class="computeroutput"><span class="identifier">c</span></code>.
 287                     </p>
 288                   </td>
 289 </tr>
 290 <tr>
 291 <td>
 292                     <p>
 293                       <code class="computeroutput"><span class="identifier">lit</span><span class="special">(</span><span class="identifier">c</span><span class="special">)</span></code>
 294                     </p>
 295                   </td>
 296 <td>
 297                     <p>
 298                       Create a char parser from a char, <code class="computeroutput"><span class="identifier">c</span></code>.
 299                     </p>
 300                   </td>
 301 </tr>
 302 <tr>
 303 <td>
 304                     <p>
 305                       <code class="computeroutput"><span class="identifier">ns</span><span class="special">::</span><span class="identifier">char_</span></code>
 306                     </p>
 307                   </td>
 308 <td>
 309                     <p>
 310                       Create a char parser that matches any character in the <code class="computeroutput"><span class="identifier">ns</span></code> encoding.
 311                     </p>
 312                   </td>
 313 </tr>
 314 <tr>
 315 <td>
 316                     <p>
 317                       <code class="computeroutput"><span class="identifier">ns</span><span class="special">::</span><span class="identifier">char_</span><span class="special">(</span><span class="identifier">c</span><span class="special">)</span></code>
 318                     </p>
 319                   </td>
 320 <td>
 321                     <p>
 322                       Create a char parser with <code class="computeroutput"><span class="identifier">ns</span></code>
 323                       encoding from a char, <code class="computeroutput"><span class="identifier">c</span></code>.
 324                     </p>
 325                   </td>
 326 </tr>
 327 <tr>
 328 <td>
 329                     <p>
 330                       <code class="computeroutput"><span class="identifier">ns</span><span class="special">::</span><span class="identifier">char_</span><span class="special">(</span><span class="identifier">f</span><span class="special">,</span>
 331                       <span class="identifier">l</span><span class="special">)</span></code>
 332                     </p>
 333                   </td>
 334 <td>
 335                     <p>
 336                       Create a char-range parser that matches characters from range
 337                       (<code class="computeroutput"><span class="identifier">f</span></code> to <code class="computeroutput"><span class="identifier">l</span></code>, inclusive) with <code class="computeroutput"><span class="identifier">ns</span></code> encoding.
 338                     </p>
 339                   </td>
 340 </tr>
 341 <tr>
 342 <td>
 343                     <p>
 344                       <code class="computeroutput"><span class="identifier">ns</span><span class="special">::</span><span class="identifier">char_</span><span class="special">(</span><span class="identifier">cs</span><span class="special">)</span></code>
 345                     </p>
 346                   </td>
 347 <td>
 348                     <p>
 349                       Create a char-set parser with <code class="computeroutput"><span class="identifier">ns</span></code>
 350                       encoding from a char-set definition string, <code class="computeroutput"><span class="identifier">cs</span></code>.
 351                     </p>
 352                   </td>
 353 </tr>
 354 <tr>
 355 <td>
 356                     <p>
 357                       <code class="computeroutput"><span class="special">~</span><span class="identifier">cp</span></code>
 358                     </p>
 359                   </td>
 360 <td>
 361                     <p>
 362                       Negate <code class="computeroutput"><span class="identifier">cp</span></code>.
 363                       The result is a negated char parser that matches any character
 364                       in the <code class="computeroutput"><span class="identifier">ns</span></code> encoding
 365                       except the characters matched by <code class="computeroutput"><span class="identifier">cp</span></code>.
 366                     </p>
 367                   </td>
 368 </tr>
 369 </tbody>
 370 </table></div>
 371 <h6>
 372 <a name="spirit.qi.reference.char.char.h10"></a>
 373             <span><a name="spirit.qi.reference.char.char.attributes"></a></span><a class="link" href="char.html#spirit.qi.reference.char.char.attributes">Attributes</a>
 374           </h6>
 375 <div class="informaltable"><table class="table">
 376 <colgroup>
 377 <col>
 378 <col>
 379 </colgroup>
 380 <thead><tr>
 381 <th>
 382                     <p>
 383                       Expression
 384                     </p>
 385                   </th>
 386 <th>
 387                     <p>
 388                       Attribute
 389                     </p>
 390                   </th>
 391 </tr></thead>
 392 <tbody>
 393 <tr>
 394 <td>
 395                     <p>
 396                       <code class="computeroutput"><span class="identifier">c</span></code>
 397                     </p>
 398                   </td>
 399 <td>
 400                     <p>
 401                       <code class="computeroutput"><span class="identifier">unused</span></code> or if
 402                       <code class="computeroutput"><span class="identifier">c</span></code> is a <a class="link" href="../basics.html#spirit.qi.reference.basics.lazy_argument">Lazy Argument</a>,
 403                       the character type returned by invoking it.
 404                     </p>
 405                   </td>
 406 </tr>
 407 <tr>
 408 <td>
 409                     <p>
 410                       <code class="computeroutput"><span class="identifier">lit</span><span class="special">(</span><span class="identifier">c</span><span class="special">)</span></code>
 411                     </p>
 412                   </td>
 413 <td>
 414                     <p>
 415                       <code class="computeroutput"><span class="identifier">unused</span></code> or if
 416                       <code class="computeroutput"><span class="identifier">c</span></code> is a <a class="link" href="../basics.html#spirit.qi.reference.basics.lazy_argument">Lazy Argument</a>,
 417                       the character type returned by invoking it.
 418                     </p>
 419                   </td>
 420 </tr>
 421 <tr>
 422 <td>
 423                     <p>
 424                       <code class="computeroutput"><span class="identifier">ns</span><span class="special">::</span><span class="identifier">char_</span></code>
 425                     </p>
 426                   </td>
 427 <td>
 428                     <p>
 429                       The character type of the <a class="link" href="../basics.html#spirit.qi.reference.basics.character_encoding_namespace">Character
 430                       Encoding Namespace</a>, <code class="computeroutput"><span class="identifier">ns</span></code>.
 431                     </p>
 432                   </td>
 433 </tr>
 434 <tr>
 435 <td>
 436                     <p>
 437                       <code class="computeroutput"><span class="identifier">ns</span><span class="special">::</span><span class="identifier">char_</span><span class="special">(</span><span class="identifier">c</span><span class="special">)</span></code>
 438                     </p>
 439                   </td>
 440 <td>
 441                     <p>
 442                       The character type of the <a class="link" href="../basics.html#spirit.qi.reference.basics.character_encoding_namespace">Character
 443                       Encoding Namespace</a>, <code class="computeroutput"><span class="identifier">ns</span></code>.
 444                     </p>
 445                   </td>
 446 </tr>
 447 <tr>
 448 <td>
 449                     <p>
 450                       <code class="computeroutput"><span class="identifier">ns</span><span class="special">::</span><span class="identifier">char_</span><span class="special">(</span><span class="identifier">f</span><span class="special">,</span>
 451                       <span class="identifier">l</span><span class="special">)</span></code>
 452                     </p>
 453                   </td>
 454 <td>
 455                     <p>
 456                       The character type of the <a class="link" href="../basics.html#spirit.qi.reference.basics.character_encoding_namespace">Character
 457                       Encoding Namespace</a>, <code class="computeroutput"><span class="identifier">ns</span></code>.
 458                     </p>
 459                   </td>
 460 </tr>
 461 <tr>
 462 <td>
 463                     <p>
 464                       <code class="computeroutput"><span class="identifier">ns</span><span class="special">::</span><span class="identifier">char_</span><span class="special">(</span><span class="identifier">cs</span><span class="special">)</span></code>
 465                     </p>
 466                   </td>
 467 <td>
 468                     <p>
 469                       The character type of the <a class="link" href="../basics.html#spirit.qi.reference.basics.character_encoding_namespace">Character
 470                       Encoding Namespace</a>, <code class="computeroutput"><span class="identifier">ns</span></code>.
 471                     </p>
 472                   </td>
 473 </tr>
 474 <tr>
 475 <td>
 476                     <p>
 477                       <code class="computeroutput"><span class="special">~</span><span class="identifier">cp</span></code>
 478                     </p>
 479                   </td>
 480 <td>
 481                     <p>
 482                       The attribute of <code class="computeroutput"><span class="identifier">cp</span></code>.
 483                     </p>
 484                   </td>
 485 </tr>
 486 </tbody>
 487 </table></div>
 488 <h6>
 489 <a name="spirit.qi.reference.char.char.h11"></a>
 490             <span><a name="spirit.qi.reference.char.char.complexity"></a></span><a class="link" href="char.html#spirit.qi.reference.char.char.complexity">Complexity</a>
 491           </h6>
 492 <div class="blockquote"><blockquote class="blockquote"><p>
 493               <span class="bold"><strong>O(N)</strong></span>, except for char-sets with 16-bit
 494               (or more) characters (e.g. <code class="computeroutput"><span class="keyword">wchar_t</span></code>).
 495               These have <span class="bold"><strong>O(log N)</strong></span> complexity, where
 496               N is the number of distinct character ranges in the set.
 497             </p></blockquote></div>
 498 <h6>
 499 <a name="spirit.qi.reference.char.char.h12"></a>
 500             <span><a name="spirit.qi.reference.char.char.example"></a></span><a class="link" href="char.html#spirit.qi.reference.char.char.example">Example</a>
 501           </h6>
 502 <div class="note"><table border="0" summary="Note">
 503 <tr>
 504 <td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="../../../../images/note.png"></td>
 505 <th align="left">Note</th>
 506 </tr>
 507 <tr><td align="left" valign="top"><p>
 508               The test harness for the example(s) below is presented in the <a class="link" href="../basics.html#spirit.qi.reference.basics.examples">Basics Examples</a>
 509               section.
 510             </p></td></tr>
 511 </table></div>
 512 <p>
 513             Some using declarations:
 514           </p>
 515 <p>
 516 </p>
 517 <pre class="programlisting"><span class="keyword">using</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">spirit</span><span class="special">::</span><span class="identifier">qi</span><span class="special">::</span><span class="identifier">lit</span><span class="special">;</span>
 518 <span class="keyword">using</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">spirit</span><span class="special">::</span><span class="identifier">ascii</span><span class="special">::</span><span class="identifier">char_</span><span class="special">;</span>
 519 </pre>
 520 <p>
 521           </p>
 522 <p>
 523             Basic literals:
 524           </p>
 525 <p>
 526 </p>
 527 <pre class="programlisting"><span class="identifier">test_parser</span><span class="special">(</span><span class="string">"x"</span><span class="special">,</span> <span class="char">'x'</span><span class="special">);</span>                      <span class="comment">// plain literal</span>
 528 <span class="identifier">test_parser</span><span class="special">(</span><span class="string">"x"</span><span class="special">,</span> <span class="identifier">lit</span><span class="special">(</span><span class="char">'x'</span><span class="special">));</span>                 <span class="comment">// explicit literal</span>
 529 <span class="identifier">test_parser</span><span class="special">(</span><span class="string">"x"</span><span class="special">,</span> <span class="identifier">char_</span><span class="special">(</span><span class="char">'x'</span><span class="special">));</span>               <span class="comment">// ascii::char_</span>
 530 </pre>
 531 <p>
 532           </p>
 533 <p>
 534             Range:
 535           </p>
 536 <p>
 537 </p>
 538 <pre class="programlisting"><span class="keyword">char</span> <span class="identifier">ch</span><span class="special">;</span>
 539 <span class="identifier">test_parser_attr</span><span class="special">(</span><span class="string">"5"</span><span class="special">,</span> <span class="identifier">char_</span><span class="special">(</span><span class="char">'0'</span><span class="special">,</span><span class="char">'9'</span><span class="special">),</span> <span class="identifier">ch</span><span class="special">);</span>  <span class="comment">// ascii::char_ range</span>
 540 <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special">&lt;&lt;</span> <span class="identifier">ch</span> <span class="special">&lt;&lt;</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span>               <span class="comment">// prints '5'</span>
 541 </pre>
 542 <p>
 543           </p>
 544 <p>
 545             Character set:
 546           </p>
 547 <p>
 548 </p>
 549 <pre class="programlisting"><span class="identifier">test_parser_attr</span><span class="special">(</span><span class="string">"5"</span><span class="special">,</span> <span class="identifier">char_</span><span class="special">(</span><span class="string">"0-9"</span><span class="special">),</span> <span class="identifier">ch</span><span class="special">);</span>    <span class="comment">// ascii::char_ set</span>
 550 <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special">&lt;&lt;</span> <span class="identifier">ch</span> <span class="special">&lt;&lt;</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span>               <span class="comment">// prints '5'</span>
 551 </pre>
 552 <p>
 553           </p>
 554 <p>
 555             Lazy char_ using <a href="../../../../../../phoenix/doc/html/index.html" target="_top">Phoenix</a>
 556           </p>
 557 <p>
 558 </p>
 559 <pre class="programlisting"><span class="keyword">namespace</span> <span class="identifier">phx</span> <span class="special">=</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">phoenix</span><span class="special">;</span>
 560 <span class="identifier">test_parser</span><span class="special">(</span><span class="string">"x"</span><span class="special">,</span> <span class="identifier">phx</span><span class="special">::</span><span class="identifier">val</span><span class="special">(</span><span class="char">'x'</span><span class="special">));</span>            <span class="comment">// direct</span>
 561 <span class="identifier">test_parser</span><span class="special">(</span><span class="string">"5"</span><span class="special">,</span>
 562     <span class="identifier">char_</span><span class="special">(</span><span class="identifier">phx</span><span class="special">::</span><span class="identifier">val</span><span class="special">(</span><span class="char">'0'</span><span class="special">),</span><span class="identifier">phx</span><span class="special">::</span><span class="identifier">val</span><span class="special">(</span><span class="char">'9'</span><span class="special">)));</span>    <span class="comment">// ascii::char_ range</span>
 563 </pre>
 564 <p>
 565           </p>
 566 </div>
 567 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 568 <td align="left"></td>
 569 <td align="right"><div class="copyright-footer">Copyright &#169; 2001-2011 Joel de Guzman, Hartmut Kaiser<p>
 570         Distributed under the Boost Software License, Version 1.0. (See accompanying
 571         file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
 572       </p>
 573 </div></td>
 574 </tr></table>
 575 <hr>
 576 <div class="spirit-nav">
 577 <a accesskey="p" href="../char.html"><img src="../../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../char.html"><img src="../../../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../../index.html"><img src="../../../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="char_class.html"><img src="../../../../../../../../doc/src/images/next.png" alt="Next"></a>
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