1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>Traits Class Requirements</title> 5<link rel="stylesheet" href="../../../../../../../doc/src/boostbook.css" type="text/css"> 6<meta name="generator" content="DocBook XSL Stylesheets V1.79.1"> 7<link rel="home" href="../../../index.html" title="Boost.Regex 5.1.4"> 8<link rel="up" href="../concepts.html" title="Concepts"> 9<link rel="prev" href="charT_concept.html" title="charT Requirements"> 10<link rel="next" href="iterator_concepts.html" title="Iterator Requirements"> 11</head> 12<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> 13<table cellpadding="2" width="100%"><tr> 14<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../../boost.png"></td> 15<td align="center"><a href="../../../../../../../index.html">Home</a></td> 16<td align="center"><a href="../../../../../../../libs/libraries.htm">Libraries</a></td> 17<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> 18<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> 19<td align="center"><a href="../../../../../../../more/index.htm">More</a></td> 20</tr></table> 21<hr> 22<div class="spirit-nav"> 23<a accesskey="p" href="charT_concept.html"><img src="../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../concepts.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="iterator_concepts.html"><img src="../../../../../../../doc/src/images/next.png" alt="Next"></a> 24</div> 25<div class="section"> 26<div class="titlepage"><div><div><h4 class="title"> 27<a name="boost_regex.ref.concepts.traits_concept"></a><a class="link" href="traits_concept.html" title="Traits Class Requirements">Traits Class 28 Requirements</a> 29</h4></div></div></div> 30<p> 31 There are two sets of requirements for the <code class="computeroutput"><span class="identifier">traits</span></code> 32 template argument to <a class="link" href="../basic_regex.html" title="basic_regex"><code class="computeroutput"><span class="identifier">basic_regex</span></code></a>: a minimal interface 33 (which is part of the regex standardization proposal), and an optional 34 Boost-specific enhanced interface. 35 </p> 36<h5> 37<a name="boost_regex.ref.concepts.traits_concept.h0"></a> 38 <span class="phrase"><a name="boost_regex.ref.concepts.traits_concept.minimal_requirements"></a></span><a class="link" href="traits_concept.html#boost_regex.ref.concepts.traits_concept.minimal_requirements">Minimal 39 requirements.</a> 40 </h5> 41<p> 42 In the following table <code class="computeroutput"><span class="identifier">X</span></code> 43 denotes a traits class defining types and functions for the character container 44 type <code class="computeroutput"><span class="identifier">charT</span></code>; <span class="emphasis"><em>u</em></span> 45 is an object of type <code class="computeroutput"><span class="identifier">X</span></code>; 46 <span class="emphasis"><em>v</em></span> is an object of type <code class="computeroutput"><span class="keyword">const</span> 47 <span class="identifier">X</span></code>; <span class="emphasis"><em>p</em></span> is 48 a value of type <code class="computeroutput"><span class="keyword">const</span> <span class="identifier">charT</span><span class="special">*</span></code>; <span class="emphasis"><em>I1</em></span> and <span class="emphasis"><em>I2</em></span> 49 are Input Iterators; <span class="emphasis"><em>c</em></span> is a value of type <code class="computeroutput"><span class="keyword">const</span> <span class="identifier">charT</span></code>; 50 <span class="emphasis"><em>s</em></span> is an object of type <code class="computeroutput"><span class="identifier">X</span><span class="special">::</span><span class="identifier">string_type</span></code>; 51 <span class="emphasis"><em>cs</em></span> is an object of type <code class="computeroutput"><span class="keyword">const</span> 52 <span class="identifier">X</span><span class="special">::</span><span class="identifier">string_type</span></code>; <span class="emphasis"><em>b</em></span> is 53 a value of type <code class="computeroutput"><span class="keyword">bool</span></code>; <span class="emphasis"><em>I</em></span> 54 is a value of type <code class="computeroutput"><span class="keyword">int</span></code>; <span class="emphasis"><em>F1</em></span> 55 and <span class="emphasis"><em>F2</em></span> are values of type <code class="computeroutput"><span class="keyword">const</span> 56 <span class="identifier">charT</span><span class="special">*</span></code>; 57 and <span class="emphasis"><em>loc</em></span> is an object of type <code class="computeroutput"><span class="identifier">X</span><span class="special">::</span><span class="identifier">locale_type</span></code>. 58 </p> 59<div class="informaltable"><table class="table"> 60<colgroup> 61<col> 62<col> 63<col> 64</colgroup> 65<thead><tr> 66<th> 67 <p> 68 Expression 69 </p> 70 </th> 71<th> 72 <p> 73 Return type 74 </p> 75 </th> 76<th> 77 <p> 78 Assertion / Note Pre / Post condition 79 </p> 80 </th> 81</tr></thead> 82<tbody> 83<tr> 84<td> 85 <p> 86 X::char_type 87 </p> 88 </td> 89<td> 90 <p> 91 charT 92 </p> 93 </td> 94<td> 95 <p> 96 The character container type used in the implementation of class 97 template basic_regex. 98 </p> 99 </td> 100</tr> 101<tr> 102<td> 103 <p> 104 X::size_type 105 </p> 106 </td> 107<td> 108 </td> 109<td> 110 <p> 111 An unsigned integer type, capable of holding the length of a 112 null-terminated string of charT's. 113 </p> 114 </td> 115</tr> 116<tr> 117<td> 118 <p> 119 X::string_type 120 </p> 121 </td> 122<td> 123 <p> 124 std::basic_string<charT> or std::vector<charT> 125 </p> 126 </td> 127<td> 128 </td> 129</tr> 130<tr> 131<td> 132 <p> 133 X::locale_type 134 </p> 135 </td> 136<td> 137 <p> 138 Implementation defined 139 </p> 140 </td> 141<td> 142 <p> 143 A copy constructible type that represents the locale used by 144 the traits class. 145 </p> 146 </td> 147</tr> 148<tr> 149<td> 150 <p> 151 X::char_class_type 152 </p> 153 </td> 154<td> 155 <p> 156 Implementation defined 157 </p> 158 </td> 159<td> 160 <p> 161 A bitmask type representing a particular character classification. 162 Multiple values of this type can be bitwise-or'ed together to 163 obtain a new valid value. 164 </p> 165 </td> 166</tr> 167<tr> 168<td> 169 <p> 170 X::length(p) 171 </p> 172 </td> 173<td> 174 <p> 175 X::size_type 176 </p> 177 </td> 178<td> 179 <p> 180 Yields the smallest i such that p[i] == 0. Complexity is linear 181 in i. 182 </p> 183 </td> 184</tr> 185<tr> 186<td> 187 <p> 188 v.translate(c) 189 </p> 190 </td> 191<td> 192 <p> 193 X::char_type 194 </p> 195 </td> 196<td> 197 <p> 198 Returns a character such that for any character d that is to 199 be considered equivalent to c then v.translate(c) == v.translate(d). 200 </p> 201 </td> 202</tr> 203<tr> 204<td> 205 <p> 206 v.translate_nocase(c) 207 </p> 208 </td> 209<td> 210 <p> 211 X::char_type 212 </p> 213 </td> 214<td> 215 <p> 216 For all characters C that are to be considered equivalent to 217 c when comparisons are to be performed without regard to case, 218 then v.translate_nocase(c) == v.translate_nocase(C). 219 </p> 220 </td> 221</tr> 222<tr> 223<td> 224 <p> 225 v.transform(F1, F2) 226 </p> 227 </td> 228<td> 229 <p> 230 X::string_type 231 </p> 232 </td> 233<td> 234 <p> 235 Returns a sort key for the character sequence designated by the 236 iterator range [F1, F2) such that if the character sequence [G1, 237 G2) sorts before the character sequence [H1, H2) then v.transform(G1, 238 G2) < v.transform(H1, H2). 239 </p> 240 </td> 241</tr> 242<tr> 243<td> 244 <p> 245 v.transform_primary(F1, F2) 246 </p> 247 </td> 248<td> 249 <p> 250 X::string_type 251 </p> 252 </td> 253<td> 254 <p> 255 Returns a sort key for the character sequence designated by the 256 iterator range [F1, F2) such that if the character sequence [G1, 257 G2) sorts before the character sequence [H1, H2) when character 258 case is not considered then v.transform_primary(G1, G2) < 259 v.transform_primary(H1, H2). 260 </p> 261 </td> 262</tr> 263<tr> 264<td> 265 <p> 266 v.lookup_classname(F1, F2) 267 </p> 268 </td> 269<td> 270 <p> 271 X::char_class_type 272 </p> 273 </td> 274<td> 275 <p> 276 Converts the character sequence designated by the iterator range 277 [F1,F2) into a bitmask type that can subsequently be passed to 278 isctype. Values returned from lookup_classname can be safely 279 bitwise or'ed together. Returns 0 if the character sequence is 280 not the name of a character class recognized by X. The value 281 returned shall be independent of the case of the characters in 282 the sequence. 283 </p> 284 </td> 285</tr> 286<tr> 287<td> 288 <p> 289 v.lookup_collatename(F1, F2) 290 </p> 291 </td> 292<td> 293 <p> 294 X::string_type 295 </p> 296 </td> 297<td> 298 <p> 299 Returns a sequence of characters that represents the collating 300 element consisting of the character sequence designated by the 301 iterator range [F1, F2). Returns an empty string if the character 302 sequence is not a valid collating element. 303 </p> 304 </td> 305</tr> 306<tr> 307<td> 308 <p> 309 v.isctype(c, v.lookup_classname (F1, F2)) 310 </p> 311 </td> 312<td> 313 <p> 314 bool 315 </p> 316 </td> 317<td> 318 <p> 319 Returns true if character c is a member of the character class 320 designated by the iterator range [F1, F2), false otherwise. 321 </p> 322 </td> 323</tr> 324<tr> 325<td> 326 <p> 327 v.value(c, I) 328 </p> 329 </td> 330<td> 331 <p> 332 int 333 </p> 334 </td> 335<td> 336 <p> 337 Returns the value represented by the digit c in base I if the 338 character c is a valid digit in base I; otherwise returns -1. 339 [Note: the value of I will only be 8, 10, or 16. -end note] 340 </p> 341 </td> 342</tr> 343<tr> 344<td> 345 <p> 346 u.imbue(loc) 347 </p> 348 </td> 349<td> 350 <p> 351 X::locale_type 352 </p> 353 </td> 354<td> 355 <p> 356 Imbues u with the locale loc, returns the previous locale used 357 by u if any. 358 </p> 359 </td> 360</tr> 361<tr> 362<td> 363 <p> 364 v.getloc() 365 </p> 366 </td> 367<td> 368 <p> 369 X::locale_type 370 </p> 371 </td> 372<td> 373 <p> 374 Returns the current locale used by v if any. 375 </p> 376 </td> 377</tr> 378</tbody> 379</table></div> 380<h5> 381<a name="boost_regex.ref.concepts.traits_concept.h1"></a> 382 <span class="phrase"><a name="boost_regex.ref.concepts.traits_concept.additional_optional_requirements"></a></span><a class="link" href="traits_concept.html#boost_regex.ref.concepts.traits_concept.additional_optional_requirements">Additional 383 Optional Requirements</a> 384 </h5> 385<p> 386 The following additional requirements are strictly optional, however in 387 order for <a class="link" href="../basic_regex.html" title="basic_regex"><code class="computeroutput"><span class="identifier">basic_regex</span></code></a> 388 to take advantage of these additional interfaces, all of the following 389 requirements must be met; <a class="link" href="../basic_regex.html" title="basic_regex"><code class="computeroutput"><span class="identifier">basic_regex</span></code></a> will detect the presence 390 or absence of the member <code class="computeroutput"><span class="identifier">boost_extensions_tag</span></code> 391 and configure itself appropriately. 392 </p> 393<div class="informaltable"><table class="table"> 394<colgroup> 395<col> 396<col> 397<col> 398</colgroup> 399<thead><tr> 400<th> 401 <p> 402 Expression 403 </p> 404 </th> 405<th> 406 <p> 407 Result 408 </p> 409 </th> 410<th> 411 <p> 412 Assertion / Note Pre / Post condition 413 </p> 414 </th> 415</tr></thead> 416<tbody> 417<tr> 418<td> 419 <p> 420 X::boost_extensions_tag 421 </p> 422 </td> 423<td> 424 <p> 425 An unspecified type. 426 </p> 427 </td> 428<td> 429 <p> 430 When present, all of the extensions listed in this table must 431 be present. 432 </p> 433 </td> 434</tr> 435<tr> 436<td> 437 <p> 438 v.syntax_type(c) 439 </p> 440 </td> 441<td> 442 <p> 443 regex_constants::syntax_type 444 </p> 445 </td> 446<td> 447 <p> 448 Returns a symbolic value of type regex_constants::syntax_type 449 that signifies the meaning of character c within the regular 450 expression grammar. 451 </p> 452 </td> 453</tr> 454<tr> 455<td> 456 <p> 457 v.escape_syntax_type(c) 458 </p> 459 </td> 460<td> 461 <p> 462 regex_constants::escape_syntax_type 463 </p> 464 </td> 465<td> 466 <p> 467 Returns a symbolic value of type regex_constants::escape_syntax_type, 468 that signifies the meaning of character c within the regular 469 expression grammar, when c has been preceded by an escape character. 470 Precondition: if b is the character preceding c in the expression 471 being parsed then: <code class="computeroutput"><span class="identifier">v</span><span class="special">.</span><span class="identifier">syntax_type</span><span class="special">(</span><span class="identifier">b</span><span class="special">)</span> <span class="special">==</span> 472 <span class="identifier">syntax_escape</span></code> 473 </p> 474 </td> 475</tr> 476<tr> 477<td> 478 <p> 479 v.translate(c, b) 480 </p> 481 </td> 482<td> 483 <p> 484 X::char_type 485 </p> 486 </td> 487<td> 488 <p> 489 Returns a character d such that: for any character d that is 490 to be considered equivalent to c then <code class="computeroutput"><span class="identifier">v</span><span class="special">.</span><span class="identifier">translate</span><span class="special">(</span><span class="identifier">c</span><span class="special">,</span><span class="keyword">false</span><span class="special">)==</span><span class="identifier">v</span><span class="special">.</span><span class="identifier">translate</span><span class="special">(</span><span class="identifier">d</span><span class="special">,</span><span class="keyword">false</span><span class="special">)</span></code>. Likewise for all characters 491 C that are to be considered equivalent to c when comparisons 492 are to be performed without regard to case, then <code class="computeroutput"><span class="identifier">v</span><span class="special">.</span><span class="identifier">translate</span><span class="special">(</span><span class="identifier">c</span><span class="special">,</span><span class="keyword">true</span><span class="special">)==</span><span class="identifier">v</span><span class="special">.</span><span class="identifier">translate</span><span class="special">(</span><span class="identifier">C</span><span class="special">,</span><span class="keyword">true</span><span class="special">)</span></code>. 493 </p> 494 </td> 495</tr> 496<tr> 497<td> 498 <p> 499 v.toi(I1, I2, i) 500 </p> 501 </td> 502<td> 503 <p> 504 An integer type capable of holding either a charT or an int. 505 </p> 506 </td> 507<td> 508 <p> 509 Behaves as follows: if <code class="computeroutput"><span class="identifier">p</span> 510 <span class="special">==</span> <span class="identifier">q</span></code> 511 or if <code class="computeroutput"><span class="special">*</span><span class="identifier">p</span></code> 512 is not a digit character then returns -1. Otherwise performs 513 formatted numeric input on the sequence [p,q) and returns the 514 result as an int. Postcondition: either p == q or *p is a non-digit 515 character. 516 </p> 517 </td> 518</tr> 519<tr> 520<td> 521 <p> 522 v.error_string(I) 523 </p> 524 </td> 525<td> 526 <p> 527 std::string 528 </p> 529 </td> 530<td> 531 <p> 532 Returns a human readable error string for the error condition 533 i, where i is one of the values enumerated by type regex_constants::error_type. 534 If the value <span class="emphasis"><em>I</em></span> is not recognized then returns 535 the string "Unknown error" or a localized equivalent. 536 </p> 537 </td> 538</tr> 539<tr> 540<td> 541 <p> 542 v.tolower(c) 543 </p> 544 </td> 545<td> 546 <p> 547 X::char_type 548 </p> 549 </td> 550<td> 551 <p> 552 Converts c to lower case, used for Perl-style \l and \L formatting 553 operations. 554 </p> 555 </td> 556</tr> 557<tr> 558<td> 559 <p> 560 v.toupper(c) 561 </p> 562 </td> 563<td> 564 <p> 565 X::char_type 566 </p> 567 </td> 568<td> 569 <p> 570 Converts c to upper case, used for Perl-style \u and \U formatting 571 operations. 572 </p> 573 </td> 574</tr> 575</tbody> 576</table></div> 577</div> 578<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 579<td align="left"></td> 580<td align="right"><div class="copyright-footer">Copyright © 1998-2013 John Maddock<p> 581 Distributed under the Boost Software License, Version 1.0. 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