1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>regex_iterator</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="../ref.html" title="Reference"> 9<link rel="prev" href="regex_replace.html" title="regex_replace"> 10<link rel="next" href="regex_token_iterator.html" title="regex_token_iterator"> 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 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href="regex_iterator.html" title="regex_iterator"><code class="computeroutput"><span class="identifier">regex_iterator</span></code></a> will enumerate all 31 of the regular expression matches found in some sequence: dereferencing a 32 <a class="link" href="regex_iterator.html" title="regex_iterator"><code class="computeroutput"><span class="identifier">regex_iterator</span></code></a> 33 yields a reference to a <a class="link" href="match_results.html" title="match_results"><code class="computeroutput"><span class="identifier">match_results</span></code></a> object. 34 </p> 35<pre class="programlisting"><span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">BidirectionalIterator</span><span class="special">,</span> 36 <span class="keyword">class</span> <span class="identifier">charT</span> <span class="special">=</span> <span class="identifier">iterator_traits</span><span class="special"><</span><span class="identifier">BidirectionalIterator</span><span class="special">>::</span><span class="identifier">value_type</span><span class="special">,</span> 37 <span class="keyword">class</span> <span class="identifier">traits</span> <span class="special">=</span> <span class="identifier">regex_traits</span><span class="special"><</span><span class="identifier">charT</span><span class="special">></span> <span class="special">></span> 38<span class="keyword">class</span> <span class="identifier">regex_iterator</span> 39<span class="special">{</span> 40<span class="keyword">public</span><span class="special">:</span> 41 <span class="keyword">typedef</span> <span class="identifier">basic_regex</span><span class="special"><</span><span class="identifier">charT</span><span class="special">,</span> <span class="identifier">traits</span><span class="special">></span> <span class="identifier">regex_type</span><span class="special">;</span> 42 <span class="keyword">typedef</span> <span class="identifier">match_results</span><span class="special"><</span><span class="identifier">BidirectionalIterator</span><span class="special">></span> <span class="identifier">value_type</span><span class="special">;</span> 43 <span class="keyword">typedef</span> <span class="keyword">typename</span> <span class="identifier">iterator_traits</span><span class="special"><</span><span class="identifier">BidirectionalIterator</span><span class="special">>::</span><span class="identifier">difference_type</span> <span class="identifier">difference_type</span><span class="special">;</span> 44 <span class="keyword">typedef</span> <span class="keyword">const</span> <span class="identifier">value_type</span><span class="special">*</span> <span class="identifier">pointer</span><span class="special">;</span> 45 <span class="keyword">typedef</span> <span class="keyword">const</span> <span class="identifier">value_type</span><span class="special">&</span> <span class="identifier">reference</span><span class="special">;</span> 46 <span class="keyword">typedef</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">forward_iterator_tag</span> <span class="identifier">iterator_category</span><span class="special">;</span> 47 48 <a class="link" href="regex_iterator.html#boost_regex.regex_iterator.construct1">regex_iterator</a><span class="special">();</span> 49 <a class="link" href="regex_iterator.html#boost_regex.regex_iterator.construct2">regex_iterator</a><span class="special">(</span><span class="identifier">BidirectionalIterator</span> <span class="identifier">a</span><span class="special">,</span> <span class="identifier">BidirectionalIterator</span> <span class="identifier">b</span><span class="special">,</span> 50 <span class="keyword">const</span> <span class="identifier">regex_type</span><span class="special">&</span> <span class="identifier">re</span><span class="special">,</span> 51 <span class="identifier">match_flag_type</span> <span class="identifier">m</span> <span class="special">=</span> <span class="identifier">match_default</span><span class="special">);</span> 52 <a class="link" href="regex_iterator.html#boost_regex.regex_iterator.construct3">regex_iterator</a><span class="special">(</span><span class="keyword">const</span> <span class="identifier">regex_iterator</span><span class="special">&);</span> 53 <span class="identifier">regex_iterator</span><span class="special">&</span> <a class="link" href="regex_iterator.html#boost_regex.regex_iterator.assign">operator=(</a><span class="keyword">const</span> <span class="identifier">regex_iterator</span><span class="special">&);</span> 54 <span class="keyword">bool</span> <a class="link" href="regex_iterator.html#boost_regex.regex_iterator.op_eq">operator==</a><span class="special">(</span><span class="keyword">const</span> <span class="identifier">regex_iterator</span><span class="special">&)</span><span class="keyword">const</span><span class="special">;</span> 55 <span class="keyword">bool</span> <a class="link" href="regex_iterator.html#boost_regex.regex_iterator.op_ne">operator!=</a><span class="special">(</span><span class="keyword">const</span> <span class="identifier">regex_iterator</span><span class="special">&)</span><span class="keyword">const</span><span class="special">;</span> 56 <span class="keyword">const</span> <span class="identifier">value_type</span><span class="special">&</span> <a class="link" href="regex_iterator.html#boost_regex.regex_iterator.op_deref">operator*</a><span class="special">()</span><span class="keyword">const</span><span class="special">;</span> 57 <span class="keyword">const</span> <span class="identifier">value_type</span><span class="special">*</span> <a class="link" href="regex_iterator.html#boost_regex.regex_iterator.op_arrow">operator-></a><span class="special">()</span><span class="keyword">const</span><span class="special">;</span> 58 <span class="identifier">regex_iterator</span><span class="special">&</span> <a class="link" href="regex_iterator.html#boost_regex.regex_iterator.op_inc">operator++</a><span class="special">();</span> 59 <span class="identifier">regex_iterator</span> <a class="link" href="regex_iterator.html#boost_regex.regex_iterator.op_inc2">operator++</a><span class="special">(</span><span class="keyword">int</span><span class="special">);</span> 60<span class="special">};</span> 61 62<span class="keyword">typedef</span> <span class="identifier">regex_iterator</span><span class="special"><</span><span class="keyword">const</span> <span class="keyword">char</span><span class="special">*></span> <span class="identifier">cregex_iterator</span><span class="special">;</span> 63<span class="keyword">typedef</span> <span class="identifier">regex_iterator</span><span class="special"><</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">::</span><span class="identifier">const_iterator</span><span class="special">></span> <span class="identifier">sregex_iterator</span><span class="special">;</span> 64 65<span class="preprocessor">#ifndef</span> <span class="identifier">BOOST_NO_WREGEX</span> 66<span class="keyword">typedef</span> <span class="identifier">regex_iterator</span><span class="special"><</span><span class="keyword">const</span> <span class="keyword">wchar_t</span><span class="special">*></span> <span class="identifier">wcregex_iterator</span><span class="special">;</span> 67<span class="keyword">typedef</span> <span class="identifier">regex_iterator</span><span class="special"><</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">wstring</span><span class="special">::</span><span class="identifier">const_iterator</span><span class="special">></span> <span class="identifier">wsregex_iterator</span><span class="special">;</span> 68<span class="preprocessor">#endif</span> 69 70<span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">charT</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">traits</span><span class="special">></span> <span class="identifier">regex_iterator</span><span class="special"><</span><span class="keyword">const</span> <span class="identifier">charT</span><span class="special">*,</span> <span class="identifier">charT</span><span class="special">,</span> <span class="identifier">traits</span><span class="special">></span> 71 <a class="link" href="regex_iterator.html#boost_regex.regex_iterator.make">make_regex_iterator</a><span class="special">(</span><span class="keyword">const</span> <span class="identifier">charT</span><span class="special">*</span> <span class="identifier">p</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">basic_regex</span><span class="special"><</span><span class="identifier">charT</span><span class="special">,</span> <span class="identifier">traits</span><span class="special">>&</span> <span class="identifier">e</span><span class="special">,</span> 72 <span class="identifier">regex_constants</span><span class="special">::</span><span class="identifier">match_flag_type</span> <span class="identifier">m</span> <span class="special">=</span> <span class="identifier">regex_constants</span><span class="special">::</span><span class="identifier">match_default</span><span class="special">);</span> 73 74<span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">charT</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">traits</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">ST</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">SA</span><span class="special">></span> 75 <span class="identifier">regex_iterator</span><span class="special"><</span><span class="keyword">typename</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_string</span><span class="special"><</span><span class="identifier">charT</span><span class="special">,</span> <span class="identifier">ST</span><span class="special">,</span> <span class="identifier">SA</span><span class="special">>::</span><span class="identifier">const_iterator</span><span class="special">,</span> <span class="identifier">charT</span><span class="special">,</span> <span class="identifier">traits</span><span class="special">></span> 76 <a class="link" href="regex_iterator.html#boost_regex.regex_iterator.make">make_regex_iterator</a><span class="special">(</span><span class="keyword">const</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_string</span><span class="special"><</span><span class="identifier">charT</span><span class="special">,</span> <span class="identifier">ST</span><span class="special">,</span> <span class="identifier">SA</span><span class="special">>&</span> <span class="identifier">p</span><span class="special">,</span> 77 <span class="keyword">const</span> <span class="identifier">basic_regex</span><span class="special"><</span><span class="identifier">charT</span><span class="special">,</span> <span class="identifier">traits</span><span class="special">>&</span> <span class="identifier">e</span><span class="special">,</span> 78 <span class="identifier">regex_constants</span><span class="special">::</span><span class="identifier">match_flag_type</span> <span class="identifier">m</span> <span class="special">=</span> <span class="identifier">regex_constants</span><span class="special">::</span><span class="identifier">match_default</span><span class="special">);</span> 79</pre> 80<h5> 81<a name="boost_regex.ref.regex_iterator.h0"></a> 82 <span class="phrase"><a name="boost_regex.ref.regex_iterator.description"></a></span><a class="link" href="regex_iterator.html#boost_regex.ref.regex_iterator.description">Description</a> 83 </h5> 84<p> 85 A <a class="link" href="regex_iterator.html" title="regex_iterator"><code class="computeroutput"><span class="identifier">regex_iterator</span></code></a> 86 is constructed from a pair of iterators, and enumerates all occurrences of 87 a regular expression within that iterator range. 88 </p> 89<a name="boost_regex.regex_iterator.construct1"></a><pre class="programlisting"><span class="identifier">regex_iterator</span><span class="special">();</span> 90</pre> 91<p> 92 <span class="bold"><strong>Effects</strong></span>: constructs an end of sequence 93 <a class="link" href="regex_iterator.html" title="regex_iterator"><code class="computeroutput"><span class="identifier">regex_iterator</span></code></a>. 94 </p> 95<a name="boost_regex.regex_iterator.construct2"></a><pre class="programlisting"><span class="identifier">regex_iterator</span><span class="special">(</span><span class="identifier">BidirectionalIterator</span> <span class="identifier">a</span><span class="special">,</span> <span class="identifier">BidirectionalIterator</span> <span class="identifier">b</span><span class="special">,</span> 96 <span class="keyword">const</span> <span class="identifier">regex_type</span><span class="special">&</span> <span class="identifier">re</span><span class="special">,</span> 97 <span class="identifier">match_flag_type</span> <span class="identifier">m</span> <span class="special">=</span> <span class="identifier">match_default</span><span class="special">);</span> 98</pre> 99<p> 100 <span class="bold"><strong>Effects</strong></span>: constructs a <a class="link" href="regex_iterator.html" title="regex_iterator"><code class="computeroutput"><span class="identifier">regex_iterator</span></code></a> that will enumerate 101 all occurrences of the expression <span class="emphasis"><em>re</em></span>, within the sequence 102 [a,b), and found using <a class="link" href="match_flag_type.html" title="match_flag_type"><code class="computeroutput"><span class="identifier">match_flag_type</span></code></a> <span class="emphasis"><em>m</em></span>. 103 The object <span class="emphasis"><em>re</em></span> must exist for the lifetime of the <a class="link" href="regex_iterator.html" title="regex_iterator"><code class="computeroutput"><span class="identifier">regex_iterator</span></code></a>. 104 </p> 105<p> 106 <span class="bold"><strong>Throws</strong></span>: <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">runtime_error</span></code> 107 if the complexity of matching the expression against an N character string 108 begins to exceed O(N<sup>2</sup>), or if the program runs out of stack space while matching 109 the expression (if Boost.Regex is configured in recursive mode), or if the 110 matcher exhausts its permitted memory allocation (if Boost.Regex is configured 111 in non-recursive mode). 112 </p> 113<a name="boost_regex.regex_iterator.construct3"></a><pre class="programlisting"><span class="identifier">regex_iterator</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">regex_iterator</span><span class="special">&</span> <span class="identifier">that</span><span class="special">);</span> 114</pre> 115<p> 116 <span class="bold"><strong>Effects</strong></span>: constructs a copy of <code class="computeroutput"><span class="identifier">that</span></code>. 117 </p> 118<p> 119 <span class="bold"><strong>Postconditions</strong></span>: <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span> <span class="special">==</span> <span class="identifier">that</span></code>. 120 </p> 121<a name="boost_regex.regex_iterator.assign"></a><pre class="programlisting"><span class="identifier">regex_iterator</span><span class="special">&</span> <span class="keyword">operator</span><span class="special">=(</span><span class="keyword">const</span> <span class="identifier">regex_iterator</span><span class="special">&);</span> 122</pre> 123<p> 124 <span class="bold"><strong>Effects</strong></span>: sets <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> equal to those in <code class="computeroutput"><span class="identifier">that</span></code>. 125 </p> 126<p> 127 <span class="bold"><strong>Postconditions</strong></span>: *this == that. 128 </p> 129<a name="boost_regex.regex_iterator.op_eq"></a><pre class="programlisting"><span class="keyword">bool</span> <span class="keyword">operator</span><span class="special">==(</span><span class="keyword">const</span> <span class="identifier">regex_iterator</span><span class="special">&</span> <span class="identifier">that</span><span class="special">)</span><span class="keyword">const</span><span class="special">;</span> 130</pre> 131<p> 132 <span class="bold"><strong>Effects</strong></span>: returns true if *this is equal 133 to that. 134 </p> 135<a name="boost_regex.regex_iterator.op_ne"></a><pre class="programlisting"><span class="keyword">bool</span> <span class="keyword">operator</span><span class="special">!=(</span><span class="keyword">const</span> <span class="identifier">regex_iterator</span><span class="special">&)</span><span class="keyword">const</span><span class="special">;</span> 136</pre> 137<p> 138 <span class="bold"><strong>Effects</strong></span>: returns <code class="computeroutput"><span class="special">!(*</span><span class="keyword">this</span> <span class="special">==</span> <span class="identifier">that</span><span class="special">)</span></code>. 139 </p> 140<a name="boost_regex.regex_iterator.op_deref"></a><pre class="programlisting"><span class="keyword">const</span> <span class="identifier">value_type</span><span class="special">&</span> <span class="keyword">operator</span><span class="special">*()</span><span class="keyword">const</span><span class="special">;</span> 141</pre> 142<p> 143 <span class="bold"><strong>Effects</strong></span>: dereferencing a <a class="link" href="regex_iterator.html" title="regex_iterator"><code class="computeroutput"><span class="identifier">regex_iterator</span></code></a> object it yields 144 a const reference to a <a class="link" href="match_results.html" title="match_results"><code class="computeroutput"><span class="identifier">match_results</span></code></a> object, whose members 145 are set as follows: 146 </p> 147<div class="informaltable"><table class="table"> 148<colgroup> 149<col> 150<col> 151</colgroup> 152<thead><tr> 153<th> 154 <p> 155 Element 156 </p> 157 </th> 158<th> 159 <p> 160 Value 161 </p> 162 </th> 163</tr></thead> 164<tbody> 165<tr> 166<td> 167 <p> 168 <code class="computeroutput"><span class="special">(*</span><span class="identifier">it</span><span class="special">).</span><span class="identifier">size</span><span class="special">()</span></code> 169 </p> 170 </td> 171<td> 172 <p> 173 <code class="computeroutput"><span class="number">1</span> <span class="special">+</span> 174 <span class="identifier">re</span><span class="special">.</span><span class="identifier">mark_count</span><span class="special">()</span></code> 175 </p> 176 </td> 177</tr> 178<tr> 179<td> 180 <p> 181 <code class="computeroutput"><span class="special">(*</span><span class="identifier">it</span><span class="special">).</span><span class="identifier">empty</span><span class="special">()</span></code> 182 </p> 183 </td> 184<td> 185 <p> 186 <code class="computeroutput"><span class="keyword">false</span></code> 187 </p> 188 </td> 189</tr> 190<tr> 191<td> 192 <p> 193 <code class="computeroutput"><span class="special">(*</span><span class="identifier">it</span><span class="special">).</span><span class="identifier">prefix</span><span class="special">().</span><span class="identifier">first</span></code> 194 </p> 195 </td> 196<td> 197 <p> 198 The end of the last match found, or the start of the underlying 199 sequence if this is the first match enumerated 200 </p> 201 </td> 202</tr> 203<tr> 204<td> 205 <p> 206 <code class="computeroutput"><span class="special">(*</span><span class="identifier">it</span><span class="special">).</span><span class="identifier">prefix</span><span class="special">().</span><span class="identifier">last</span></code> 207 </p> 208 </td> 209<td> 210 <p> 211 The same as the start of the match found: <code class="computeroutput"><span class="special">(*</span><span class="identifier">it</span><span class="special">)[</span><span class="number">0</span><span class="special">].</span><span class="identifier">first</span></code> 212 </p> 213 </td> 214</tr> 215<tr> 216<td> 217 <p> 218 <code class="computeroutput"><span class="special">(*</span><span class="identifier">it</span><span class="special">).</span><span class="identifier">prefix</span><span class="special">().</span><span class="identifier">matched</span></code> 219 </p> 220 </td> 221<td> 222 <p> 223 True if the prefix did not match an empty string: <code class="computeroutput"><span class="special">(*</span><span class="identifier">it</span><span class="special">).</span><span class="identifier">prefix</span><span class="special">().</span><span class="identifier">first</span> 224 <span class="special">!=</span> <span class="special">(*</span><span class="identifier">it</span><span class="special">).</span><span class="identifier">prefix</span><span class="special">().</span><span class="identifier">second</span></code> 225 </p> 226 </td> 227</tr> 228<tr> 229<td> 230 <p> 231 <code class="computeroutput"><span class="special">(*</span><span class="identifier">it</span><span class="special">).</span><span class="identifier">suffix</span><span class="special">().</span><span class="identifier">first</span></code> 232 </p> 233 </td> 234<td> 235 <p> 236 The same as the end of the match found: <code class="computeroutput"><span class="special">(*</span><span class="identifier">it</span><span class="special">)[</span><span class="number">0</span><span class="special">].</span><span class="identifier">second</span></code> 237 </p> 238 </td> 239</tr> 240<tr> 241<td> 242 <p> 243 <code class="computeroutput"><span class="special">(*</span><span class="identifier">it</span><span class="special">).</span><span class="identifier">suffix</span><span class="special">().</span><span class="identifier">last</span></code> 244 </p> 245 </td> 246<td> 247 <p> 248 The end of the underlying sequence. 249 </p> 250 </td> 251</tr> 252<tr> 253<td> 254 <p> 255 <code class="computeroutput"><span class="special">(*</span><span class="identifier">it</span><span class="special">).</span><span class="identifier">suffix</span><span class="special">().</span><span class="identifier">matched</span></code> 256 </p> 257 </td> 258<td> 259 <p> 260 True if the suffix did not match an empty string: <code class="computeroutput"><span class="special">(*</span><span class="identifier">it</span><span class="special">).</span><span class="identifier">suffix</span><span class="special">().</span><span class="identifier">first</span> 261 <span class="special">!=</span> <span class="special">(*</span><span class="identifier">it</span><span class="special">).</span><span class="identifier">suffix</span><span class="special">().</span><span class="identifier">second</span></code> 262 </p> 263 </td> 264</tr> 265<tr> 266<td> 267 <p> 268 <code class="computeroutput"><span class="special">(*</span><span class="identifier">it</span><span class="special">)[</span><span class="number">0</span><span class="special">].</span><span class="identifier">first</span></code> 269 </p> 270 </td> 271<td> 272 <p> 273 The start of the sequence of characters that matched the regular 274 expression 275 </p> 276 </td> 277</tr> 278<tr> 279<td> 280 <p> 281 <code class="computeroutput"><span class="special">(*</span><span class="identifier">it</span><span class="special">)[</span><span class="number">0</span><span class="special">].</span><span class="identifier">second</span></code> 282 </p> 283 </td> 284<td> 285 <p> 286 The end of the sequence of characters that matched the regular 287 expression 288 </p> 289 </td> 290</tr> 291<tr> 292<td> 293 <p> 294 <code class="computeroutput"><span class="special">(*</span><span class="identifier">it</span><span class="special">)[</span><span class="number">0</span><span class="special">].</span><span class="identifier">matched</span></code> 295 </p> 296 </td> 297<td> 298 <p> 299 true if a full match was found, and false if it was a partial match 300 (found as a result of the match_partial flag being set). 301 </p> 302 </td> 303</tr> 304<tr> 305<td> 306 <p> 307 <code class="computeroutput"><span class="special">(*</span><span class="identifier">it</span><span class="special">)[</span><span class="identifier">n</span><span class="special">].</span><span class="identifier">first</span></code> 308 </p> 309 </td> 310<td> 311 <p> 312 For all integers <code class="computeroutput"><span class="identifier">n</span> <span class="special"><</span> <span class="special">(*</span><span class="identifier">it</span><span class="special">).</span><span class="identifier">size</span><span class="special">()</span></code>, 313 the start of the sequence that matched sub-expression <span class="emphasis"><em>n</em></span>. 314 Alternatively, if sub-expression <span class="emphasis"><em>n</em></span> did not 315 participate in the match, then last. 316 </p> 317 </td> 318</tr> 319<tr> 320<td> 321 <p> 322 <code class="computeroutput"><span class="special">(*</span><span class="identifier">it</span><span class="special">)[</span><span class="identifier">n</span><span class="special">].</span><span class="identifier">second</span></code> 323 </p> 324 </td> 325<td> 326 <p> 327 For all integers <code class="computeroutput"><span class="identifier">n</span> <span class="special"><</span> <span class="special">(*</span><span class="identifier">it</span><span class="special">).</span><span class="identifier">size</span><span class="special">()</span></code>, 328 the end of the sequence that matched sub-expression <span class="emphasis"><em>n</em></span>. 329 Alternatively, if sub-expression <span class="emphasis"><em>n</em></span> did not 330 participate in the match, then last. 331 </p> 332 </td> 333</tr> 334<tr> 335<td> 336 <p> 337 <code class="computeroutput"><span class="special">(*</span><span class="identifier">it</span><span class="special">)[</span><span class="identifier">n</span><span class="special">].</span><span class="identifier">matched</span></code> 338 </p> 339 </td> 340<td> 341 <p> 342 For all integers <code class="computeroutput"><span class="identifier">n</span> <span class="special"><</span> <span class="special">(*</span><span class="identifier">it</span><span class="special">).</span><span class="identifier">size</span><span class="special">()</span></code>, 343 true if sub-expression <span class="emphasis"><em>n</em></span> participated in the 344 match, false otherwise. 345 </p> 346 </td> 347</tr> 348<tr> 349<td> 350 <p> 351 <code class="computeroutput"><span class="special">(*</span><span class="identifier">it</span><span class="special">).</span><span class="identifier">position</span><span class="special">(</span><span class="identifier">n</span><span class="special">)</span></code> 352 </p> 353 </td> 354<td> 355 <p> 356 For all integers <code class="computeroutput"><span class="identifier">n</span> <span class="special"><</span> <span class="special">(*</span><span class="identifier">it</span><span class="special">).</span><span class="identifier">size</span><span class="special">()</span></code>, 357 then the distance from the start of the underlying sequence to 358 the start of sub-expression match <span class="emphasis"><em>n</em></span>. 359 </p> 360 </td> 361</tr> 362</tbody> 363</table></div> 364<a name="boost_regex.regex_iterator.op_arrow"></a><pre class="programlisting"><span class="keyword">const</span> <span class="identifier">value_type</span><span class="special">*</span> <span class="keyword">operator</span><span class="special">->()</span><span class="keyword">const</span><span class="special">;</span> 365</pre> 366<p> 367 <span class="bold"><strong>Effects</strong></span>: returns <code class="computeroutput"><span class="special">&(*</span><span class="keyword">this</span><span class="special">)</span></code>. 368 </p> 369<a name="boost_regex.regex_iterator.op_inc"></a><pre class="programlisting"><span class="identifier">regex_iterator</span><span class="special">&</span> <span class="keyword">operator</span><span class="special">++();</span> 370</pre> 371<p> 372 <span class="bold"><strong>Effects</strong></span>: moves the iterator to the next 373 match in the underlying sequence, or the end of sequence iterator if none 374 if found. When the last match found matched a zero length string, then the 375 <a class="link" href="regex_iterator.html" title="regex_iterator"><code class="computeroutput"><span class="identifier">regex_iterator</span></code></a> 376 will find the next match as follows: if there exists a non-zero length match 377 that starts at the same location as the last one, then returns it, otherwise 378 starts looking for the next (possibly zero length) match from one position 379 to the right of the last match. 380 </p> 381<p> 382 <span class="bold"><strong>Throws</strong></span>: <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">runtime_error</span></code> 383 if the complexity of matching the expression against an N character string 384 begins to exceed O(N<sup>2</sup>), or if the program runs out of stack space while matching 385 the expression (if Boost.Regex is configured in recursive mode), or if the 386 matcher exhausts its permitted memory allocation (if Boost.Regex is configured 387 in non-recursive mode). 388 </p> 389<p> 390 <span class="bold"><strong>Returns</strong></span>: *this. 391 </p> 392<a name="boost_regex.regex_iterator.op_inc2"></a><pre class="programlisting"><span class="identifier">regex_iterator</span> <span class="keyword">operator</span><span class="special">++(</span><span class="keyword">int</span><span class="special">);</span> 393</pre> 394<p> 395 <span class="bold"><strong>Effects</strong></span>: constructs a copy result of <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code>, then 396 calls <code class="computeroutput"><span class="special">++(*</span><span class="keyword">this</span><span class="special">)</span></code>. 397 </p> 398<p> 399 <span class="bold"><strong>Returns</strong></span>: result. 400 </p> 401<a name="boost_regex.regex_iterator.make"></a><pre class="programlisting"><span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">charT</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">traits</span><span class="special">></span> 402<span class="identifier">regex_iterator</span><span class="special"><</span><span class="keyword">const</span> <span class="identifier">charT</span><span class="special">*,</span> <span class="identifier">charT</span><span class="special">,</span> <span class="identifier">traits</span><span class="special">></span> 403 <span class="identifier">make_regex_iterator</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">charT</span><span class="special">*</span> <span class="identifier">p</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">basic_regex</span><span class="special"><</span><span class="identifier">charT</span><span class="special">,</span> <span class="identifier">traits</span><span class="special">>&</span> <span class="identifier">e</span><span class="special">,</span> 404 <span class="identifier">regex_constants</span><span class="special">::</span><span class="identifier">match_flag_type</span> <span class="identifier">m</span> <span class="special">=</span> <span class="identifier">regex_constants</span><span class="special">::</span><span class="identifier">match_default</span><span class="special">);</span> 405 406<span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">charT</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">traits</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">ST</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">SA</span><span class="special">></span> 407<span class="identifier">regex_iterator</span><span class="special"><</span><span class="keyword">typename</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_string</span><span class="special"><</span><span class="identifier">charT</span><span class="special">,</span> <span class="identifier">ST</span><span class="special">,</span> <span class="identifier">SA</span><span class="special">>::</span><span class="identifier">const_iterator</span><span class="special">,</span> <span class="identifier">charT</span><span class="special">,</span> <span class="identifier">traits</span><span class="special">></span> 408 <span class="identifier">make_regex_iterator</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_string</span><span class="special"><</span><span class="identifier">charT</span><span class="special">,</span> <span class="identifier">ST</span><span class="special">,</span> <span class="identifier">SA</span><span class="special">>&</span> <span class="identifier">p</span><span class="special">,</span> 409 <span class="keyword">const</span> <span class="identifier">basic_regex</span><span class="special"><</span><span class="identifier">charT</span><span class="special">,</span> <span class="identifier">traits</span><span class="special">>&</span> <span class="identifier">e</span><span class="special">,</span> 410 <span class="identifier">regex_constants</span><span class="special">::</span><span class="identifier">match_flag_type</span> <span class="identifier">m</span> <span class="special">=</span> <span class="identifier">regex_constants</span><span class="special">::</span><span class="identifier">match_default</span><span class="special">);</span> 411</pre> 412<p> 413 <span class="bold"><strong>Effects</strong></span>: returns an iterator that enumerates 414 all occurrences of expression <span class="emphasis"><em>e</em></span> in text <span class="emphasis"><em>p</em></span> 415 using <a class="link" href="match_flag_type.html" title="match_flag_type"><code class="computeroutput"><span class="identifier">match_flag_type</span></code></a> 416 <span class="emphasis"><em>m</em></span>. 417 </p> 418<h5> 419<a name="boost_regex.ref.regex_iterator.h1"></a> 420 <span class="phrase"><a name="boost_regex.ref.regex_iterator.examples"></a></span><a class="link" href="regex_iterator.html#boost_regex.ref.regex_iterator.examples">Examples</a> 421 </h5> 422<p> 423 The following example takes a C++ source file and builds up an index of class 424 names, and the location of that class in the file. 425 </p> 426<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">string</span><span class="special">></span> 427<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">map</span><span class="special">></span> 428<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">fstream</span><span class="special">></span> 429<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">iostream</span><span class="special">></span> 430<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">regex</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> 431 432<span class="keyword">using</span> <span class="keyword">namespace</span> <span class="identifier">std</span><span class="special">;</span> 433 434<span class="comment">// purpose:</span> 435<span class="comment">// takes the contents of a file in the form of a string</span> 436<span class="comment">// and searches for all the C++ class definitions, storing</span> 437<span class="comment">// their locations in a map of strings/int's</span> 438 439<span class="keyword">typedef</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">map</span><span class="special"><</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">,</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">::</span><span class="identifier">difference_type</span><span class="special">,</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">less</span><span class="special"><</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">></span> <span class="special">></span> <span class="identifier">map_type</span><span class="special">;</span> 440 441<span class="keyword">const</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">re</span> <span class="special">=</span> 442 <span class="comment">// possibly leading whitespace: </span> 443 <span class="string">"^[[:space:]]*"</span> 444 <span class="comment">// possible template declaration:</span> 445 <span class="string">"(template[[:space:]]*<[^;:{]+>[[:space:]]*)?"</span> 446 <span class="comment">// class or struct:</span> 447 <span class="string">"(class|struct)[[:space:]]*"</span> 448 <span class="comment">// leading declspec macros etc:</span> 449 <span class="string">"("</span> 450 <span class="string">"\\<\\w+\\>"</span> 451 <span class="string">"("</span> 452 <span class="string">"[[:blank:]]*\\([^)]*\\)"</span> 453 <span class="string">")?"</span> 454 <span class="string">"[[:space:]]*"</span> 455 <span class="string">")*"</span> 456 <span class="comment">// the class name</span> 457 <span class="string">"(\\<\\w*\\>)[[:space:]]*"</span> 458 <span class="comment">// template specialisation parameters</span> 459 <span class="string">"(<[^;:{]+>)?[[:space:]]*"</span> 460 <span class="comment">// terminate in { or :</span> 461 <span class="string">"(\\{|:[^;\\{()]*\\{)"</span><span class="special">;</span> 462 463 464<span class="identifier">boost</span><span class="special">::</span><span class="identifier">regex</span> <span class="identifier">expression</span><span class="special">(</span><span class="identifier">re</span><span class="special">);</span> 465<span class="identifier">map_type</span> <span class="identifier">class_index</span><span class="special">;</span> 466 467<span class="keyword">bool</span> <span class="identifier">regex_callback</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">match_results</span><span class="special"><</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">::</span><span class="identifier">const_iterator</span><span class="special">>&</span> <span class="identifier">what</span><span class="special">)</span> 468<span class="special">{</span> 469 <span class="comment">// what[0] contains the whole string</span> 470 <span class="comment">// what[5] contains the class name.</span> 471 <span class="comment">// what[6] contains the template specialisation if any.</span> 472 <span class="comment">// add class name and position to map:</span> 473 <span class="identifier">class_index</span><span class="special">[</span><span class="identifier">what</span><span class="special">[</span><span class="number">5</span><span class="special">].</span><span class="identifier">str</span><span class="special">()</span> <span class="special">+</span> <span class="identifier">what</span><span class="special">[</span><span class="number">6</span><span class="special">].</span><span class="identifier">str</span><span class="special">()]</span> <span class="special">=</span> <span class="identifier">what</span><span class="special">.</span><span class="identifier">position</span><span class="special">(</span><span class="number">5</span><span class="special">);</span> 474 <span class="keyword">return</span> <span class="keyword">true</span><span class="special">;</span> 475<span class="special">}</span> 476 477<span class="keyword">void</span> <span class="identifier">load_file</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">&</span> <span class="identifier">s</span><span class="special">,</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">istream</span><span class="special">&</span> <span class="identifier">is</span><span class="special">)</span> 478<span class="special">{</span> 479 <span class="identifier">s</span><span class="special">.</span><span class="identifier">erase</span><span class="special">();</span> 480 <span class="identifier">s</span><span class="special">.</span><span class="identifier">reserve</span><span class="special">(</span><span class="identifier">is</span><span class="special">.</span><span class="identifier">rdbuf</span><span class="special">()-></span><span class="identifier">in_avail</span><span class="special">());</span> 481 <span class="keyword">char</span> <span class="identifier">c</span><span class="special">;</span> 482 <span class="keyword">while</span><span class="special">(</span><span class="identifier">is</span><span class="special">.</span><span class="identifier">get</span><span class="special">(</span><span class="identifier">c</span><span class="special">))</span> 483 <span class="special">{</span> 484 <span class="keyword">if</span><span class="special">(</span><span class="identifier">s</span><span class="special">.</span><span class="identifier">capacity</span><span class="special">()</span> <span class="special">==</span> <span class="identifier">s</span><span class="special">.</span><span class="identifier">size</span><span class="special">())</span> 485 <span class="identifier">s</span><span class="special">.</span><span class="identifier">reserve</span><span class="special">(</span><span class="identifier">s</span><span class="special">.</span><span class="identifier">capacity</span><span class="special">()</span> <span class="special">*</span> <span class="number">3</span><span class="special">);</span> 486 <span class="identifier">s</span><span class="special">.</span><span class="identifier">append</span><span class="special">(</span><span class="number">1</span><span class="special">,</span> <span class="identifier">c</span><span class="special">);</span> 487 <span class="special">}</span> 488<span class="special">}</span> 489 490<span class="keyword">int</span> <span class="identifier">main</span><span class="special">(</span><span class="keyword">int</span> <span class="identifier">argc</span><span class="special">,</span> <span class="keyword">const</span> <span class="keyword">char</span><span class="special">**</span> <span class="identifier">argv</span><span class="special">)</span> 491<span class="special">{</span> 492 <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span> <span class="identifier">text</span><span class="special">;</span> 493 <span class="keyword">for</span><span class="special">(</span><span class="keyword">int</span> <span class="identifier">i</span> <span class="special">=</span> <span class="number">1</span><span class="special">;</span> <span class="identifier">i</span> <span class="special"><</span> <span class="identifier">argc</span><span class="special">;</span> <span class="special">++</span><span class="identifier">i</span><span class="special">)</span> 494 <span class="special">{</span> 495 <span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"Processing file "</span> <span class="special"><<</span> <span class="identifier">argv</span><span class="special">[</span><span class="identifier">i</span><span class="special">]</span> <span class="special"><<</span> <span class="identifier">endl</span><span class="special">;</span> 496 <span class="identifier">std</span><span class="special">::</span><span class="identifier">ifstream</span> <span class="identifier">fs</span><span class="special">(</span><span class="identifier">argv</span><span class="special">[</span><span class="identifier">i</span><span class="special">]);</span> 497 <span class="identifier">load_file</span><span class="special">(</span><span class="identifier">text</span><span class="special">,</span> <span class="identifier">fs</span><span class="special">);</span> 498 <span class="comment">// construct our iterators:</span> 499 <span class="identifier">boost</span><span class="special">::</span><span class="identifier">sregex_iterator</span> <span class="identifier">m1</span><span class="special">(</span><span class="identifier">text</span><span class="special">.</span><span class="identifier">begin</span><span class="special">(),</span> <span class="identifier">text</span><span class="special">.</span><span class="identifier">end</span><span class="special">(),</span> <span class="identifier">expression</span><span class="special">);</span> 500 <span class="identifier">boost</span><span class="special">::</span><span class="identifier">sregex_iterator</span> <span class="identifier">m2</span><span class="special">;</span> 501 <span class="identifier">std</span><span class="special">::</span><span class="identifier">for_each</span><span class="special">(</span><span class="identifier">m1</span><span class="special">,</span> <span class="identifier">m2</span><span class="special">,</span> <span class="special">&</span><span class="identifier">regex_callback</span><span class="special">);</span> 502 <span class="comment">// copy results:</span> 503 <span class="identifier">cout</span> <span class="special"><<</span> <span class="identifier">class_index</span><span class="special">.</span><span class="identifier">size</span><span class="special">()</span> <span class="special"><<</span> <span class="string">" matches found"</span> <span class="special"><<</span> <span class="identifier">endl</span><span class="special">;</span> 504 <span class="identifier">map_type</span><span class="special">::</span><span class="identifier">iterator</span> <span class="identifier">c</span><span class="special">,</span> <span class="identifier">d</span><span class="special">;</span> 505 <span class="identifier">c</span> <span class="special">=</span> <span class="identifier">class_index</span><span class="special">.</span><span class="identifier">begin</span><span class="special">();</span> 506 <span class="identifier">d</span> <span class="special">=</span> <span class="identifier">class_index</span><span class="special">.</span><span class="identifier">end</span><span class="special">();</span> 507 <span class="keyword">while</span><span class="special">(</span><span class="identifier">c</span> <span class="special">!=</span> <span class="identifier">d</span><span class="special">)</span> 508 <span class="special">{</span> 509 <span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"class \""</span> <span class="special"><<</span> <span class="special">(*</span><span class="identifier">c</span><span class="special">).</span><span class="identifier">first</span> <span class="special"><<</span> <span class="string">"\" found at index: "</span> <span class="special"><<</span> <span class="special">(*</span><span class="identifier">c</span><span class="special">).</span><span class="identifier">second</span> <span class="special"><<</span> <span class="identifier">endl</span><span class="special">;</span> 510 <span class="special">++</span><span class="identifier">c</span><span class="special">;</span> 511 <span class="special">}</span> 512 <span class="identifier">class_index</span><span class="special">.</span><span class="identifier">erase</span><span class="special">(</span><span class="identifier">class_index</span><span class="special">.</span><span class="identifier">begin</span><span class="special">(),</span> <span class="identifier">class_index</span><span class="special">.</span><span class="identifier">end</span><span class="special">());</span> 513 <span class="special">}</span> 514 <span class="keyword">return</span> <span class="number">0</span><span class="special">;</span> 515<span class="special">}</span> 516</pre> 517</div> 518<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 519<td align="left"></td> 520<td align="right"><div class="copyright-footer">Copyright © 1998-2013 John Maddock<p> 521 Distributed under the Boost Software License, Version 1.0. (See accompanying 522 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>) 523 </p> 524</div></td> 525</tr></table> 526<hr> 527<div class="spirit-nav"> 528<a accesskey="p" href="regex_replace.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../ref.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="regex_token_iterator.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a> 529</div> 530</body> 531</html> 532
