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<div class="titlepage"><div><div><h3 class="title">
<a name="boost_regex.ref.match_results"></a><a class="link" href="match_results.html" title="match_results"> match_results</a>
</h3></div></div></div>
<a name="boost_regex.ref.match_results.synopsis"></a><h5>
<a name="id1055233"></a>
<a class="link" href="match_results.html#boost_regex.ref.match_results.synopsis">Synopsis</a>
</h5>
<pre class="programlisting"><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>
</pre>
<p>
Regular expressions are different from many simple pattern-matching algorithms
in that as well as finding an overall match they can also produce sub-expression
matches: each sub-expression being delimited in the pattern by a pair of
parenthesis (...). There has to be some method for reporting sub-expression
matches back to the user: this is achieved this by defining a class <code class="computeroutput"><span class="identifier">match_results</span></code> that acts as an indexed collection
of sub-expression matches, each sub-expression match being contained in an
object of type <a class="link" href="sub_match.html" title="sub_match"><code class="computeroutput"><span class="identifier">sub_match</span></code></a>.
</p>
<p>
Template class <code class="computeroutput"><span class="identifier">match_results</span></code>
denotes a collection of character sequences representing the result of a
regular expression match. Objects of type <code class="computeroutput"><span class="identifier">match_results</span></code>
are passed to the algorithms <a class="link" href="regex_match.html" title="regex_match"><code class="computeroutput"><span class="identifier">regex_match</span></code></a> and <a class="link" href="regex_search.html" title="regex_search"><code class="computeroutput"><span class="identifier">regex_search</span></code></a>, and are returned by
the iterator <a class="link" href="regex_iterator.html" title="regex_iterator"><code class="computeroutput"><span class="identifier">regex_iterator</span></code></a>. Storage for the
collection is allocated and freed as necessary by the member functions of
class <code class="computeroutput"><span class="identifier">match_results</span></code>.
</p>
<p>
The template class <code class="computeroutput"><span class="identifier">match_results</span></code>
conforms to the requirements of a Sequence, as specified in (lib.sequence.reqmts),
except that only operations defined for const-qualified Sequences are supported.
</p>
<p>
Class template <code class="computeroutput"><span class="identifier">match_results</span></code>
is most commonly used as one of the typedefs <code class="computeroutput"><span class="identifier">cmatch</span></code>,
<code class="computeroutput"><span class="identifier">wcmatch</span></code>, <code class="computeroutput"><span class="identifier">smatch</span></code>,
or <code class="computeroutput"><span class="identifier">wsmatch</span></code>:
</p>
<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>
<span class="keyword">class</span> <span class="identifier">Allocator</span> <span class="special">=</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">allocator</span><span class="special"><</span><span class="identifier">sub_match</span><span class="special"><</span><span class="identifier">BidirectionalIterator</span><span class="special">></span> <span class="special">></span>
<span class="keyword">class</span> <span class="identifier">match_results</span><span class="special">;</span>
<span class="keyword">typedef</span> <span class="identifier">match_results</span><span class="special"><</span><span class="keyword">const</span> <span class="keyword">char</span><span class="special">*></span> <span class="identifier">cmatch</span><span class="special">;</span>
<span class="keyword">typedef</span> <span class="identifier">match_results</span><span class="special"><</span><span class="keyword">const</span> <span class="keyword">wchar_t</span><span class="special">*></span> <span class="identifier">wcmatch</span><span class="special">;</span>
<span class="keyword">typedef</span> <span class="identifier">match_results</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">smatch</span><span class="special">;</span>
<span class="keyword">typedef</span> <span class="identifier">match_results</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">wsmatch</span><span class="special">;</span>
<span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">BidirectionalIterator</span><span class="special">,</span>
<span class="keyword">class</span> <span class="identifier">Allocator</span> <span class="special">=</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">allocator</span><span class="special"><</span><span class="identifier">sub_match</span><span class="special"><</span><span class="identifier">BidirectionalIterator</span><span class="special">></span> <span class="special">></span>
<span class="keyword">class</span> <span class="identifier">match_results</span>
<span class="special">{</span>
<span class="keyword">public</span><span class="special">:</span>
<span class="keyword">typedef</span> <span class="identifier">sub_match</span><span class="special"><</span><span class="identifier">BidirectionalIterator</span><span class="special">></span> <span class="identifier">value_type</span><span class="special">;</span>
<span class="keyword">typedef</span> <span class="keyword">const</span> <span class="identifier">value_type</span><span class="special">&</span> <span class="identifier">const_reference</span><span class="special">;</span>
<span class="keyword">typedef</span> <span class="identifier">const_reference</span> <span class="identifier">reference</span><span class="special">;</span>
<span class="keyword">typedef</span> <span class="identifier">implementation</span> <span class="identifier">defined</span> <span class="identifier">const_iterator</span><span class="special">;</span>
<span class="keyword">typedef</span> <span class="identifier">const_iterator</span> <span class="identifier">iterator</span><span class="special">;</span>
<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>
<span class="keyword">typedef</span> <span class="keyword">typename</span> <span class="identifier">Allocator</span><span class="special">::</span><span class="identifier">size_type</span> <span class="identifier">size_type</span><span class="special">;</span>
<span class="keyword">typedef</span> <span class="identifier">Allocator</span> <span class="identifier">allocator_type</span><span class="special">;</span>
<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">value_type</span> <span class="identifier">char_type</span><span class="special">;</span>
<span class="keyword">typedef</span> <span class="identifier">basic_string</span><span class="special"><</span><span class="identifier">char_type</span><span class="special">></span> <span class="identifier">string_type</span><span class="special">;</span>
<span class="comment">// construct/copy/destroy:
</span> <a class="link" href="match_results.html#boost_regex.match_results.construct">explicit match_results</a><span class="special">(</span><span class="keyword">const</span> <span class="identifier">Allocator</span><span class="special">&</span> <span class="identifier">a</span> <span class="special">=</span> <span class="identifier">Allocator</span><span class="special">());</span>
<a class="link" href="match_results.html#boost_regex.match_results.copy_construct">match_results</a><span class="special">(</span><span class="keyword">const</span> <span class="identifier">match_results</span><span class="special">&</span> <span class="identifier">m</span><span class="special">);</span>
<a class="link" href="match_results.html#boost_regex.match_results.assign">match_results& operator=</a><span class="special">(</span><span class="keyword">const</span> <span class="identifier">match_results</span><span class="special">&</span> <span class="identifier">m</span><span class="special">);</span>
<span class="special">~</span><span class="identifier">match_results</span><span class="special">();</span>
<span class="comment">// size:
</span> <span class="identifier">size_type</span> <a class="link" href="match_results.html#boost_regex.match_results.size">size</a><span class="special">()</span> <span class="keyword">const</span><span class="special">;</span>
<span class="identifier">size_type</span> <a class="link" href="match_results.html#boost_regex.match_results.max_size">max_size</a><span class="special">()</span> <span class="keyword">const</span><span class="special">;</span>
<span class="keyword">bool</span> <a class="link" href="match_results.html#boost_regex.match_results.empty">empty</a><span class="special">()</span> <span class="keyword">const</span><span class="special">;</span>
<span class="comment">// element access:
</span> <span class="identifier">difference_type</span> <a class="link" href="match_results.html#boost_regex.match_results.length">length</a><span class="special">(</span><span class="keyword">int</span> <span class="identifier">sub</span> <span class="special">=</span> <span class="number">0</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
<span class="identifier">difference_type</span> <a class="link" href="match_results.html#boost_regex.match_results.length">length</a><span class="special">(</span><span class="keyword">const</span> <span class="identifier">char_type</span><span class="special">*</span> <span class="identifier">sub</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
<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="identifier">difference_type</span> <a class="link" href="match_results.html#boost_regex.match_results.length">length</a><span class="special">(</span><span class="keyword">const</span> <span class="identifier">charT</span><span class="special">*</span> <span class="identifier">sub</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
<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">A</span><span class="special">></span>
<span class="identifier">difference_type</span> <a class="link" href="match_results.html#boost_regex.match_results.length">length</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">Traits</span><span class="special">,</span> <span class="identifier">A</span><span class="special">>&</span> <span class="identifier">sub</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
<span class="identifier">difference_type</span> <a class="link" href="match_results.html#boost_regex.match_results.position">position</a><span class="special">(</span><span class="keyword">unsigned</span> <span class="keyword">int</span> <span class="identifier">sub</span> <span class="special">=</span> <span class="number">0</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
<span class="identifier">difference_type</span> <a class="link" href="match_results.html#boost_regex.match_results.position">position</a><span class="special">(</span><span class="keyword">const</span> <span class="identifier">char_type</span><span class="special">*</span> <span class="identifier">sub</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
<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="identifier">difference_type</span> <a class="link" href="match_results.html#boost_regex.match_results.position">position</a><span class="special">(</span><span class="keyword">const</span> <span class="identifier">charT</span><span class="special">*</span> <span class="identifier">sub</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
<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">A</span><span class="special">></span>
<span class="identifier">difference_type</span> <a class="link" href="match_results.html#boost_regex.match_results.position">position</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">Traits</span><span class="special">,</span> <span class="identifier">A</span><span class="special">>&</span> <span class="identifier">sub</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
<span class="identifier">string_type</span> <a class="link" href="match_results.html#boost_regex.match_results.str">str</a><span class="special">(</span><span class="keyword">int</span> <span class="identifier">sub</span> <span class="special">=</span> <span class="number">0</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
<span class="identifier">string_type</span> <a class="link" href="match_results.html#boost_regex.match_results.str">str</a><span class="special">(</span><span class="keyword">const</span> <span class="identifier">char_type</span><span class="special">*</span> <span class="identifier">sub</span><span class="special">)</span><span class="keyword">const</span><span class="special">;</span>
<span class="keyword">template</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">A</span><span class="special">></span>
<span class="identifier">string_type</span> <a class="link" href="match_results.html#boost_regex.match_results.str">str</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">char_type</span><span class="special">,</span> <span class="identifier">Traits</span><span class="special">,</span> <span class="identifier">A</span><span class="special">>&</span> <span class="identifier">sub</span><span class="special">)</span><span class="keyword">const</span><span class="special">;</span>
<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="identifier">string_type</span> <a class="link" href="match_results.html#boost_regex.match_results.str">str</a><span class="special">(</span><span class="keyword">const</span> <span class="identifier">charT</span><span class="special">*</span> <span class="identifier">sub</span><span class="special">)</span><span class="keyword">const</span><span class="special">;</span>
<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">A</span><span class="special">></span>
<span class="identifier">string_type</span> <a class="link" href="match_results.html#boost_regex.match_results.str">str</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">Traits</span><span class="special">,</span> <span class="identifier">A</span><span class="special">>&</span> <span class="identifier">sub</span><span class="special">)</span><span class="keyword">const</span><span class="special">;</span>
<span class="identifier">const_reference</span> <a class="link" href="match_results.html#boost_regex.match_results.subscript">operator[]</a><span class="special">(</span><span class="keyword">int</span> <span class="identifier">n</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
<span class="identifier">const_reference</span> <a class="link" href="match_results.html#boost_regex.match_results.subscript">operator[]</a><span class="special">(</span><span class="keyword">const</span> <span class="identifier">char_type</span><span class="special">*</span> <span class="identifier">n</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
<span class="keyword">template</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">A</span><span class="special">></span>
<span class="identifier">const_reference</span> <a class="link" href="match_results.html#boost_regex.match_results.subscript">operator[]</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">char_type</span><span class="special">,</span> <span class="identifier">Traits</span><span class="special">,</span> <span class="identifier">A</span><span class="special">>&</span> <span class="identifier">n</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
<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="identifier">const_reference</span> <a class="link" href="match_results.html#boost_regex.match_results.subscript">operator[]</a><span class="special">(</span><span class="keyword">const</span> <span class="identifier">charT</span><span class="special">*</span> <span class="identifier">n</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
<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">A</span><span class="special">></span>
<span class="identifier">const_reference</span> <a class="link" href="match_results.html#boost_regex.match_results.subscript">operator[]</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">Traits</span><span class="special">,</span> <span class="identifier">A</span><span class="special">>&</span> <span class="identifier">n</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
<span class="identifier">const_reference</span> <a class="link" href="match_results.html#boost_regex.match_results.prefix">prefix</a><span class="special">()</span> <span class="keyword">const</span><span class="special">;</span>
<span class="identifier">const_reference</span> <a class="link" href="match_results.html#boost_regex.match_results.suffix">suffix</a><span class="special">()</span> <span class="keyword">const</span><span class="special">;</span>
<span class="identifier">const_iterator</span> <a class="link" href="match_results.html#boost_regex.match_results.begin">begin</a><span class="special">()</span> <span class="keyword">const</span><span class="special">;</span>
<span class="identifier">const_iterator</span> <a class="link" href="match_results.html#boost_regex.match_results.end">end</a><span class="special">()</span> <span class="keyword">const</span><span class="special">;</span>
<span class="comment">// format:
</span> <span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">OutputIterator</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">Formatter</span><span class="special">></span>
<span class="identifier">OutputIterator</span> <a class="link" href="match_results.html#boost_regex.match_results.format">format</a><span class="special">(</span><span class="identifier">OutputIterator</span> <span class="identifier">out</span><span class="special">,</span>
<span class="identifier">Formatter</span> <span class="identifier">fmt</span><span class="special">,</span>
<span class="identifier">match_flag_type</span> <span class="identifier">flags</span> <span class="special">=</span> <span class="identifier">format_default</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
<span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">Formatter</span><span class="special">></span>
<span class="identifier">string_type</span> <a class="link" href="match_results.html#boost_regex.match_results.format2">format</a><span class="special">(</span><span class="identifier">Formatter</span> <span class="identifier">fmt</span><span class="special">,</span>
<span class="identifier">match_flag_type</span> <span class="identifier">flags</span> <span class="special">=</span> <span class="identifier">format_default</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
<span class="identifier">allocator_type</span> <a class="link" href="match_results.html#boost_regex.match_results.get_allocator">get_allocator</a><span class="special">()</span> <span class="keyword">const</span><span class="special">;</span>
<span class="keyword">void</span> <a class="link" href="match_results.html#boost_regex.match_results.swap">swap</a><span class="special">(</span><span class="identifier">match_results</span><span class="special">&</span> <span class="identifier">that</span><span class="special">);</span>
<span class="preprocessor">#ifdef</span> <span class="identifier">BOOST_REGEX_MATCH_EXTRA</span>
<span class="keyword">typedef</span> <span class="keyword">typename</span> <span class="identifier">value_type</span><span class="special">::</span><span class="identifier">capture_sequence_type</span> <span class="identifier">capture_sequence_type</span><span class="special">;</span>
<span class="keyword">const</span> <span class="identifier">capture_sequence_type</span><span class="special">&</span> <a class="link" href="match_results.html#boost_regex.match_results.captures">captures</a><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">i</span><span class="special">)</span><span class="keyword">const</span><span class="special">;</span>
<span class="preprocessor">#endif</span>
<span class="special">};</span>
<span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">BidirectionalIterator</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">Allocator</span><span class="special">></span>
<span class="keyword">bool</span> <a class="link" href="match_results.html#boost_regex.match_results.op_eq">operator ==</a> <span class="special">(</span><span class="keyword">const</span> <span class="identifier">match_results</span><span class="special"><</span><span class="identifier">BidirectionalIterator</span><span class="special">,</span> <span class="identifier">Allocator</span><span class="special">>&</span> <span class="identifier">m1</span><span class="special">,</span>
<span class="keyword">const</span> <span class="identifier">match_results</span><span class="special"><</span><span class="identifier">BidirectionalIterator</span><span class="special">,</span> <span class="identifier">Allocator</span><span class="special">>&</span> <span class="identifier">m2</span><span class="special">);</span>
<span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">BidirectionalIterator</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">Allocator</span><span class="special">></span>
<span class="keyword">bool</span> <a class="link" href="match_results.html#boost_regex.match_results.op_ne">operator !=</a> <span class="special">(</span><span class="keyword">const</span> <span class="identifier">match_results</span><span class="special"><</span><span class="identifier">BidirectionalIterator</span><span class="special">,</span> <span class="identifier">Allocator</span><span class="special">>&</span> <span class="identifier">m1</span><span class="special">,</span>
<span class="keyword">const</span> <span class="identifier">match_results</span><span class="special"><</span><span class="identifier">BidirectionalIterator</span><span class="special">,</span> <span class="identifier">Allocator</span><span class="special">>&</span> <span class="identifier">m2</span><span class="special">);</span>
<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">BidirectionalIterator</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">Allocator</span><span class="special">></span>
<span class="identifier">basic_ostream</span><span class="special"><</span><span class="identifier">charT</span><span class="special">,</span> <span class="identifier">traits</span><span class="special">>&</span>
<a class="link" href="match_results.html#boost_regex.match_results.op_stream">operator <<</a> <span class="special">(</span><span class="identifier">basic_ostream</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">os</span><span class="special">,</span>
<span class="keyword">const</span> <span class="identifier">match_results</span><span class="special"><</span><span class="identifier">BidirectionalIterator</span><span class="special">,</span> <span class="identifier">Allocator</span><span class="special">>&</span> <span class="identifier">m</span><span class="special">);</span>
<span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">BidirectionalIterator</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">Allocator</span><span class="special">></span>
<span class="keyword">void</span> <a class="link" href="match_results.html#boost_regex.match_results.op_swap">swap</a><span class="special">(</span><span class="identifier">match_results</span><span class="special"><</span><span class="identifier">BidirectionalIterator</span><span class="special">,</span> <span class="identifier">Allocator</span><span class="special">>&</span> <span class="identifier">m1</span><span class="special">,</span>
<span class="identifier">match_results</span><span class="special"><</span><span class="identifier">BidirectionalIterator</span><span class="special">,</span> <span class="identifier">Allocator</span><span class="special">>&</span> <span class="identifier">m2</span><span class="special">);</span>
</pre>
<a name="boost_regex.ref.match_results.description"></a><h5>
<a name="id1058963"></a>
<a class="link" href="match_results.html#boost_regex.ref.match_results.description">Description</a>
</h5>
<p>
In all <code class="computeroutput"><span class="identifier">match_results</span></code> constructors,
a copy of the Allocator argument is used for any memory allocation performed
by the constructor or member functions during the lifetime of the object.
</p>
<a name="boost_regex.match_results.construct"></a><p>
</p>
<pre class="programlisting"><span class="identifier">match_results</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">Allocator</span><span class="special">&</span> <span class="identifier">a</span> <span class="special">=</span> <span class="identifier">Allocator</span><span class="special">());</span>
</pre>
<p>
<span class="bold"><strong>Effects</strong></span>: Constructs an object of class
<code class="computeroutput"><span class="identifier">match_results</span></code>. The postconditions
of this function are indicated in the table:
</p>
<div class="informaltable"><table class="table">
<colgroup>
<col>
<col>
</colgroup>
<thead><tr>
<th>
<p>
Element
</p>
</th>
<th>
<p>
Value
</p>
</th>
</tr></thead>
<tbody>
<tr>
<td>
<p>
empty()
</p>
</td>
<td>
<p>
true
</p>
</td>
</tr>
<tr>
<td>
<p>
size()
</p>
</td>
<td>
<p>
0
</p>
</td>
</tr>
<tr>
<td>
<p>
str()
</p>
</td>
<td>
<p>
basic_string<charT>()
</p>
</td>
</tr>
</tbody>
</table></div>
<a name="boost_regex.match_results.copy_construct"></a><p>
</p>
<pre class="programlisting"><span class="identifier">match_results</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">match_results</span><span class="special">&</span> <span class="identifier">m</span><span class="special">);</span>
</pre>
<p>
<span class="bold"><strong>Effects</strong></span>: Constructs an object of class match_results,
as a copy of m.
</p>
<a name="boost_regex.match_results.assign"></a><p>
</p>
<pre class="programlisting"><span class="identifier">match_results</span><span class="special">&</span> <span class="keyword">operator</span><span class="special">=(</span><span class="keyword">const</span> <span class="identifier">match_results</span><span class="special">&</span> <span class="identifier">m</span><span class="special">);</span>
</pre>
<p>
<span class="bold"><strong>Effects</strong></span>: Assigns m to *this. The postconditions
of this function are indicated in the table:
</p>
<div class="informaltable"><table class="table">
<colgroup>
<col>
<col>
</colgroup>
<thead><tr>
<th>
<p>
Element
</p>
</th>
<th>
<p>
Value
</p>
</th>
</tr></thead>
<tbody>
<tr>
<td>
<p>
empty()
</p>
</td>
<td>
<p>
m.empty().
</p>
</td>
</tr>
<tr>
<td>
<p>
size()
</p>
</td>
<td>
<p>
m.size().
</p>
</td>
</tr>
<tr>
<td>
<p>
str(n)
</p>
</td>
<td>
<p>
m.str(n) for all integers n < m.size().
</p>
</td>
</tr>
<tr>
<td>
<p>
prefix()
</p>
</td>
<td>
<p>
m.prefix().
</p>
</td>
</tr>
<tr>
<td>
<p>
suffix()
</p>
</td>
<td>
<p>
m.suffix().
</p>
</td>
</tr>
<tr>
<td>
<p>
(*this)[n]
</p>
</td>
<td>
<p>
m[n] for all integers n < m.size().
</p>
</td>
</tr>
<tr>
<td>
<p>
length(n)
</p>
</td>
<td>
<p>
m.length(n) for all integers n < m.size().
</p>
</td>
</tr>
<tr>
<td>
<p>
position(n)
</p>
</td>
<td>
<p>
m.position(n) for all integers n < m.size().
</p>
</td>
</tr>
</tbody>
</table></div>
<a name="boost_regex.match_results.size"></a><p>
</p>
<pre class="programlisting"><span class="identifier">size_type</span> <span class="identifier">size</span><span class="special">()</span><span class="keyword">const</span><span class="special">;</span>
</pre>
<p>
<span class="bold"><strong>Effects</strong></span>: Returns the number of <a class="link" href="sub_match.html" title="sub_match"><code class="computeroutput"><span class="identifier">sub_match</span></code></a> elements stored in *this;
that is the number of marked sub-expressions in the regular expression that
was matched plus one.
</p>
<a name="boost_regex.match_results.max_size"></a><p>
</p>
<pre class="programlisting"><span class="identifier">size_type</span> <span class="identifier">max_size</span><span class="special">()</span><span class="keyword">const</span><span class="special">;</span>
</pre>
<p>
<span class="bold"><strong>Effects</strong></span>: Returns the maximum number of
<a class="link" href="sub_match.html" title="sub_match"><code class="computeroutput"><span class="identifier">sub_match</span></code></a>
elements that can be stored in *this.
</p>
<a name="boost_regex.match_results.empty"></a><p>
</p>
<pre class="programlisting"><span class="keyword">bool</span> <span class="identifier">empty</span><span class="special">()</span><span class="keyword">const</span><span class="special">;</span>
</pre>
<p>
<span class="bold"><strong>Effects</strong></span>: Returns size() == 0.
</p>
<a name="boost_regex.match_results.length"></a><p>
</p>
<pre class="programlisting"><span class="identifier">difference_type</span> <span class="identifier">length</span><span class="special">(</span><span class="keyword">int</span> <span class="identifier">sub</span> <span class="special">=</span> <span class="number">0</span><span class="special">)</span><span class="keyword">const</span><span class="special">;</span>
<span class="identifier">difference_type</span> <span class="identifier">length</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">char_type</span><span class="special">*</span> <span class="identifier">sub</span><span class="special">)</span><span class="keyword">const</span><span class="special">;</span>
<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="identifier">difference_type</span> <span class="identifier">length</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">charT</span><span class="special">*</span> <span class="identifier">sub</span><span class="special">)</span><span class="keyword">const</span><span class="special">;</span>
<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">A</span><span class="special">></span>
<span class="identifier">difference_type</span> <span class="identifier">length</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">Traits</span><span class="special">,</span> <span class="identifier">A</span><span class="special">>&)</span><span class="keyword">const</span><span class="special">;</span>
</pre>
<p>
<span class="bold"><strong>Requires</strong></span>: that the match_results object
has been initialized as a result of a successful call to <a class="link" href="regex_search.html" title="regex_search"><code class="computeroutput"><span class="identifier">regex_search</span></code></a> or <a class="link" href="regex_match.html" title="regex_match"><code class="computeroutput"><span class="identifier">regex_match</span></code></a> or was returned from
a <a class="link" href="regex_iterator.html" title="regex_iterator"><code class="computeroutput"><span class="identifier">regex_iterator</span></code></a>,
and that the underlying iterators have not been subsequently invalidated.
Will raise a <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">logic_error</span></code> if the match_results object
was not initialized.
</p>
<p>
<span class="bold"><strong>Effects</strong></span>: Returns the length of sub-expression
<span class="emphasis"><em>sub</em></span>, that is to say: <code class="computeroutput"><span class="special">(*</span><span class="keyword">this</span><span class="special">)[</span><span class="identifier">sub</span><span class="special">].</span><span class="identifier">length</span><span class="special">()</span></code>.
</p>
<p>
The overloads that accept a string refer to a named sub-expression <span class="emphasis"><em>n</em></span>.
In the event that there is no such named sub-expression then returns zero.
</p>
<p>
The template overloads of this function, allow the string and/or character
type to be different from the character type of the underlying sequence and/or
regular expression: in this case the characters will be widened to the underlying
character type of the original regular expression. A compiler error will
occur if the argument passes a wider character type than the underlying sequence.
These overloads allow a normal narrow character C string literal to be used
as an argument, even when the underlying character type of the expression
being matched may be something more exotic such as a Unicode character type.
</p>
<a name="boost_regex.match_results.position"></a><p>
</p>
<pre class="programlisting"><span class="identifier">difference_type</span> <span class="identifier">position</span><span class="special">(</span><span class="keyword">unsigned</span> <span class="keyword">int</span> <span class="identifier">sub</span> <span class="special">=</span> <span class="number">0</span><span class="special">)</span><span class="keyword">const</span><span class="special">;</span>
<span class="identifier">difference_type</span> <span class="identifier">position</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">char_type</span><span class="special">*</span> <span class="identifier">sub</span><span class="special">)</span><span class="keyword">const</span><span class="special">;</span>
<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="identifier">difference_type</span> <span class="identifier">position</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">charT</span><span class="special">*</span> <span class="identifier">sub</span><span class="special">)</span><span class="keyword">const</span><span class="special">;</span>
<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">A</span><span class="special">></span>
<span class="identifier">difference_type</span> <span class="identifier">position</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">Traits</span><span class="special">,</span> <span class="identifier">A</span><span class="special">>&)</span><span class="keyword">const</span><span class="special">;</span>
</pre>
<p>
<span class="bold"><strong>Requires</strong></span>: that the match_results object
has been initialized as a result of a successful call to <a class="link" href="regex_search.html" title="regex_search"><code class="computeroutput"><span class="identifier">regex_search</span></code></a> or <a class="link" href="regex_match.html" title="regex_match"><code class="computeroutput"><span class="identifier">regex_match</span></code></a> or was returned from
a <a class="link" href="regex_iterator.html" title="regex_iterator"><code class="computeroutput"><span class="identifier">regex_iterator</span></code></a>,
and that the underlying iterators have not been subsequently invalidated.
Will raise a <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">logic_error</span></code> if the match_results object
was not initialized.
</p>
<p>
<span class="bold"><strong>Effects</strong></span>: Returns the starting location of
sub-expression <span class="emphasis"><em>sub</em></span>, or -1 if <span class="emphasis"><em>sub</em></span>
was not matched. Note that if this represents a partial match , then <code class="computeroutput"><span class="identifier">position</span><span class="special">()</span></code>
will return the location of the partial match even though <code class="computeroutput"><span class="special">(*</span><span class="keyword">this</span><span class="special">)[</span><span class="number">0</span><span class="special">].</span><span class="identifier">matched</span></code>
is false.
</p>
<p>
The overloads that accept a string refer to a named sub-expression <span class="emphasis"><em>n</em></span>.
In the event that there is no such named sub-expression then returns -1.
</p>
<p>
The template overloads of this function, allow the string and/or character
type to be different from the character type of the underlying sequence and/or
regular expression: in this case the characters will be widened to the underlying
character type of the original regular expression. A compiler error will
occur if the argument passes a wider character type than the underlying sequence.
These overloads allow a normal narrow character C string literal to be used
as an argument, even when the underlying character type of the expression
being matched may be something more exotic such as a Unicode character type.
</p>
<a name="boost_regex.match_results.str"></a><p>
</p>
<pre class="programlisting"><span class="identifier">string_type</span> <span class="identifier">str</span><span class="special">(</span><span class="keyword">int</span> <span class="identifier">sub</span> <span class="special">=</span> <span class="number">0</span><span class="special">)</span><span class="keyword">const</span><span class="special">;</span>
<span class="identifier">string_type</span> <span class="identifier">str</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">char_type</span><span class="special">*</span> <span class="identifier">sub</span><span class="special">)</span><span class="keyword">const</span><span class="special">;</span>
<span class="keyword">template</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">A</span><span class="special">></span>
<span class="identifier">string_type</span> <span class="identifier">str</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">char_type</span><span class="special">,</span> <span class="identifier">Traits</span><span class="special">,</span> <span class="identifier">A</span><span class="special">>&</span> <span class="identifier">sub</span><span class="special">)</span><span class="keyword">const</span><span class="special">;</span>
<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="identifier">string_type</span> <span class="identifier">str</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">charT</span><span class="special">*</span> <span class="identifier">sub</span><span class="special">)</span><span class="keyword">const</span><span class="special">;</span>
<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">A</span><span class="special">></span>
<span class="identifier">string_type</span> <span class="identifier">str</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">Traits</span><span class="special">,</span> <span class="identifier">A</span><span class="special">>&</span> <span class="identifier">sub</span><span class="special">)</span><span class="keyword">const</span><span class="special">;</span>
</pre>
<p>
<span class="bold"><strong>Requires</strong></span>: that the match_results object
has been initialized as a result of a successful call to <a class="link" href="regex_search.html" title="regex_search"><code class="computeroutput"><span class="identifier">regex_search</span></code></a> or <a class="link" href="regex_match.html" title="regex_match"><code class="computeroutput"><span class="identifier">regex_match</span></code></a> or was returned from
a <a class="link" href="regex_iterator.html" title="regex_iterator"><code class="computeroutput"><span class="identifier">regex_iterator</span></code></a>,
and that the underlying iterators have not been subsequently invalidated.
Will raise a <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">logic_error</span></code> if the match_results object
was not initialized.
</p>
<p>
<span class="bold"><strong>Effects</strong></span>: Returns sub-expression <span class="emphasis"><em>sub</em></span>
as a string: <code class="computeroutput"><span class="identifier">string_type</span><span class="special">((*</span><span class="keyword">this</span><span class="special">)[</span><span class="identifier">sub</span><span class="special">])</span></code>.
</p>
<p>
The overloads that accept a string, return the string that matched the named
sub-expression <span class="emphasis"><em>n</em></span>. In the event that there is no such
named sub-expression then returns an empty string.
</p>
<p>
The template overloads of this function, allow the string and/or character
type to be different from the character type of the underlying sequence and/or
regular expression: in this case the characters will be widened to the underlying
character type of the original regular expression. A compiler error will
occur if the argument passes a wider character type than the underlying sequence.
These overloads allow a normal narrow character C string literal to be used
as an argument, even when the underlying character type of the expression
being matched may be something more exotic such as a Unicode character type.
</p>
<a name="boost_regex.match_results.subscript"></a><p>
</p>
<pre class="programlisting"><span class="identifier">const_reference</span> <span class="keyword">operator</span><span class="special">[](</span><span class="keyword">int</span> <span class="identifier">n</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
<span class="identifier">const_reference</span> <span class="keyword">operator</span><span class="special">[](</span><span class="keyword">const</span> <span class="identifier">char_type</span><span class="special">*</span> <span class="identifier">n</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
<span class="keyword">template</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">A</span><span class="special">></span>
<span class="identifier">const_reference</span> <span class="keyword">operator</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">char_type</span><span class="special">,</span> <span class="identifier">Traits</span><span class="special">,</span> <span class="identifier">A</span><span class="special">>&</span> <span class="identifier">n</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
<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="identifier">const_reference</span> <span class="keyword">operator</span><span class="special">[](</span><span class="keyword">const</span> <span class="identifier">charT</span><span class="special">*</span> <span class="identifier">n</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
<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">A</span><span class="special">></span>
<span class="identifier">const_reference</span> <span class="keyword">operator</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">Traits</span><span class="special">,</span> <span class="identifier">A</span><span class="special">>&</span> <span class="identifier">n</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
</pre>
<p>
<span class="bold"><strong>Requires</strong></span>: that the match_results object
has been initialized as a result of a successful call to <a class="link" href="regex_search.html" title="regex_search"><code class="computeroutput"><span class="identifier">regex_search</span></code></a> or <a class="link" href="regex_match.html" title="regex_match"><code class="computeroutput"><span class="identifier">regex_match</span></code></a> or was returned from
a <a class="link" href="regex_iterator.html" title="regex_iterator"><code class="computeroutput"><span class="identifier">regex_iterator</span></code></a>,
and that the underlying iterators have not been subsequently invalidated.
Will raise a <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">logic_error</span></code> if the match_results object
was not initialized.
</p>
<p>
<span class="bold"><strong>Effects</strong></span>: Returns a reference to the <a class="link" href="sub_match.html" title="sub_match"><code class="computeroutput"><span class="identifier">sub_match</span></code></a>
object representing the character sequence that matched marked sub-expression
<span class="emphasis"><em>n</em></span>. If <code class="computeroutput"><span class="identifier">n</span> <span class="special">==</span> <span class="number">0</span></code> then returns
a reference to a <a class="link" href="sub_match.html" title="sub_match"><code class="computeroutput"><span class="identifier">sub_match</span></code></a> object representing the
character sequence that matched the whole regular expression. If <span class="emphasis"><em>n</em></span>
is out of range, or if <span class="emphasis"><em>n</em></span> is an unmatched sub-expression,
then returns a <a class="link" href="sub_match.html" title="sub_match"><code class="computeroutput"><span class="identifier">sub_match</span></code></a>
object whose matched member is false.
</p>
<p>
The overloads that accept a string, return a reference to the <a class="link" href="sub_match.html" title="sub_match"><code class="computeroutput"><span class="identifier">sub_match</span></code></a> object representing the
character sequence that matched the named sub-expression <span class="emphasis"><em>n</em></span>.
In the event that there is no such named sub-expression then returns a <a class="link" href="sub_match.html" title="sub_match"><code class="computeroutput"><span class="identifier">sub_match</span></code></a>
object whose matched member is false.
</p>
<p>
The template overloads of this function, allow the string and/or character
type to be different from the character type of the underlying sequence and/or
regular expression: in this case the characters will be widened to the underlying
character type of the original regular expression. A compiler error will
occur if the argument passes a wider character type than the underlying sequence.
These overloads allow a normal narrow character C string literal to be used
as an argument, even when the underlying character type of the expression
being matched may be something more exotic such as a Unicode character type.
</p>
<a name="boost_regex.match_results.prefix"></a><p>
</p>
<pre class="programlisting"><span class="identifier">const_reference</span> <span class="identifier">prefix</span><span class="special">()</span><span class="keyword">const</span><span class="special">;</span>
</pre>
<p>
<span class="bold"><strong>Requires</strong></span>: that the match_results object
has been initialized as a result of a successful call to <a class="link" href="regex_search.html" title="regex_search"><code class="computeroutput"><span class="identifier">regex_search</span></code></a> or <a class="link" href="regex_match.html" title="regex_match"><code class="computeroutput"><span class="identifier">regex_match</span></code></a> or was returned from
a <a class="link" href="regex_iterator.html" title="regex_iterator"><code class="computeroutput"><span class="identifier">regex_iterator</span></code></a>,
and that the underlying iterators have not been subsequently invalidated.
Will raise a <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">logic_error</span></code> if the match_results object
was not initialized.
</p>
<p>
<span class="bold"><strong>Effects</strong></span>: Returns a reference to the <a class="link" href="sub_match.html" title="sub_match"><code class="computeroutput"><span class="identifier">sub_match</span></code></a>
object representing the character sequence from the start of the string being
matched or searched, to the start of the match found.
</p>
<a name="boost_regex.match_results.suffix"></a><p>
</p>
<pre class="programlisting"><span class="identifier">const_reference</span> <span class="identifier">suffix</span><span class="special">()</span><span class="keyword">const</span><span class="special">;</span>
</pre>
<p>
<span class="bold"><strong>Requires</strong></span>: that the match_results object
has been initialized as a result of a successful call to <a class="link" href="regex_search.html" title="regex_search"><code class="computeroutput"><span class="identifier">regex_search</span></code></a> or <a class="link" href="regex_match.html" title="regex_match"><code class="computeroutput"><span class="identifier">regex_match</span></code></a> or was returned from
a <a class="link" href="regex_iterator.html" title="regex_iterator"><code class="computeroutput"><span class="identifier">regex_iterator</span></code></a>,
and that the underlying iterators have not been subsequently invalidated.
Will raise a <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">logic_error</span></code> if the match_results object
was not initialized.
</p>
<p>
<span class="bold"><strong>Effects</strong></span>: Returns a reference to the <a class="link" href="sub_match.html" title="sub_match"><code class="computeroutput"><span class="identifier">sub_match</span></code></a>
object representing the character sequence from the end of the match found
to the end of the string being matched or searched.
</p>
<a name="boost_regex.match_results.begin"></a><p>
</p>
<pre class="programlisting"><span class="identifier">const_iterator</span> <span class="identifier">begin</span><span class="special">()</span><span class="keyword">const</span><span class="special">;</span>
</pre>
<p>
<span class="bold"><strong>Effects</strong></span>: Returns a starting iterator that
enumerates over all the marked sub-expression matches stored in *this.
</p>
<a name="boost_regex.match_results.end"></a><p>
</p>
<pre class="programlisting"><span class="identifier">const_iterator</span> <span class="identifier">end</span><span class="special">()</span><span class="keyword">const</span><span class="special">;</span>
</pre>
<p>
<span class="bold"><strong>Effects</strong></span>: Returns a terminating iterator
that enumerates over all the marked sub-expression matches stored in *this.
</p>
<a name="boost_regex.match_results_format"></a><a name="boost_regex.match_results.format"></a><p>
</p>
<pre class="programlisting"><span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">OutputIterator</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">Formatter</span><span class="special">></span>
<span class="identifier">OutputIterator</span> <span class="identifier">format</span><span class="special">(</span><span class="identifier">OutputIterator</span> <span class="identifier">out</span><span class="special">,</span>
<span class="identifier">Formatter</span> <span class="identifier">fmt</span><span class="special">,</span>
<span class="identifier">match_flag_type</span> <span class="identifier">flags</span> <span class="special">=</span> <span class="identifier">format_default</span><span class="special">);</span>
</pre>
<p>
<span class="bold"><strong>Requires</strong></span>: The type <code class="computeroutput"><span class="identifier">OutputIterator</span></code>
conforms to the Output Iterator requirements (C++ std 24.1.2).
</p>
<p>
The type <code class="computeroutput"><span class="identifier">Formatter</span></code> must be
either a pointer to a null-terminated string of type <code class="computeroutput"><span class="identifier">char_type</span><span class="special">[]</span></code>, or be a container of <code class="computeroutput"><span class="identifier">char_type</span></code>'s
(for example <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_string</span><span class="special"><</span><span class="identifier">char_type</span><span class="special">></span></code>)
or be a unary, binary or ternary functor that computes the replacement string
from a function call: either <code class="computeroutput"><span class="identifier">fmt</span><span class="special">(*</span><span class="keyword">this</span><span class="special">)</span></code>
which must return a container of <code class="computeroutput"><span class="identifier">char_type</span></code>'s
to be used as the replacement text, or either <code class="computeroutput"><span class="identifier">fmt</span><span class="special">(*</span><span class="keyword">this</span><span class="special">,</span>
<span class="identifier">out</span><span class="special">)</span></code>
or <code class="computeroutput"><span class="identifier">fmt</span><span class="special">(*</span><span class="keyword">this</span><span class="special">,</span> <span class="identifier">out</span><span class="special">,</span> <span class="identifier">flags</span><span class="special">)</span></code>, both of which write the replacement text
to <code class="computeroutput"><span class="special">*</span><span class="identifier">out</span></code>,
and then return the new OutputIterator position. Note that if the formatter
is a functor, then it is <span class="emphasis"><em>passed by value</em></span>: users that
want to pass function objects with internal state might want to use <a href="../../../../../../doc/html/ref.html" target="_top">Boost.Ref</a> to wrap the object
so that it's passed by reference.
</p>
<p>
<span class="bold"><strong>Requires</strong></span>: that the match_results object
has been initialized as a result of a successful call to <a class="link" href="regex_search.html" title="regex_search"><code class="computeroutput"><span class="identifier">regex_search</span></code></a> or <a class="link" href="regex_match.html" title="regex_match"><code class="computeroutput"><span class="identifier">regex_match</span></code></a> or was returned from
a <a class="link" href="regex_iterator.html" title="regex_iterator"><code class="computeroutput"><span class="identifier">regex_iterator</span></code></a>,
and that the underlying iterators have not been subsequently invalidated.
Will raise a <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">logic_error</span></code> if the match_results object
was not initialized.
</p>
<p>
<span class="bold"><strong>Effects</strong></span>: If <code class="computeroutput"><span class="identifier">fmt</span></code>
is either a null-terminated string, or a container of <code class="computeroutput"><span class="identifier">char_type</span></code>'s,
then copies the character sequence <code class="computeroutput"><span class="special">[</span><span class="identifier">fmt</span><span class="special">.</span><span class="identifier">begin</span><span class="special">(),</span> <span class="identifier">fmt</span><span class="special">.</span><span class="identifier">end</span><span class="special">())</span></code>
to <code class="computeroutput"><span class="identifier">OutputIterator</span></code> <span class="emphasis"><em>out</em></span>.
For each format specifier or escape sequence in <span class="emphasis"><em>fmt</em></span>,
replace that sequence with either the character(s) it represents, or the
sequence of characters within <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> to which it refers. The bitmasks specified
in flags determines what format specifiers or escape sequences are recognized,
by default this is the format used by ECMA-262, ECMAScript Language Specification,
Chapter 15 part 5.4.11 String.prototype.replace.
</p>
<p>
If <code class="computeroutput"><span class="identifier">fmt</span></code> is a function object,
then depending on the number of arguments the function object accepts, it
will either:
</p>
<div class="itemizedlist"><ul type="disc">
<li>
Call <code class="computeroutput"><span class="identifier">fmt</span><span class="special">(*</span><span class="keyword">this</span><span class="special">)</span></code>
and copy the string returned to <code class="computeroutput"><span class="identifier">OutputIterator</span></code>
<span class="emphasis"><em>out</em></span>.
</li>
<li>
Call <code class="computeroutput"><span class="identifier">fmt</span><span class="special">(*</span><span class="keyword">this</span><span class="special">,</span> <span class="identifier">out</span><span class="special">)</span></code>.
</li>
<li>
Call <code class="computeroutput"><span class="identifier">fmt</span><span class="special">(*</span><span class="keyword">this</span><span class="special">,</span> <span class="identifier">out</span><span class="special">,</span> <span class="identifier">flags</span><span class="special">)</span></code>.
</li>
</ul></div>
<p>
In all cases the new position of the <code class="computeroutput"><span class="identifier">OutputIterator</span></code>
is returned.
</p>
<p>
See the <a class="link" href="../format.html" title="Search and Replace Format String Syntax">format syntax guide for more information</a>.
</p>
<p>
<span class="bold"><strong>Returns</strong></span>: out.
</p>
<a name="boost_regex.match_results.format2"></a><p>
</p>
<pre class="programlisting"><span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">Formatter</span><span class="special">></span>
<span class="identifier">string_type</span> <span class="identifier">format</span><span class="special">(</span><span class="identifier">Formatter</span> <span class="identifier">fmt</span><span class="special">,</span>
<span class="identifier">match_flag_type</span> <span class="identifier">flags</span> <span class="special">=</span> <span class="identifier">format_default</span><span class="special">);</span>
</pre>
<p>
<span class="bold"><strong>Requires</strong></span> The type <code class="computeroutput"><span class="identifier">Formatter</span></code>
must be either a pointer to a null-terminated string of type <code class="computeroutput"><span class="identifier">char_type</span><span class="special">[]</span></code>,
or be a container of <code class="computeroutput"><span class="identifier">char_type</span></code>'s
(for example <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_string</span><span class="special"><</span><span class="identifier">char_type</span><span class="special">></span></code>)
or be a unary, binary or ternary functor that computes the replacement string
from a function call: either <code class="computeroutput"><span class="identifier">fmt</span><span class="special">(*</span><span class="keyword">this</span><span class="special">)</span></code>
which must return a container of <code class="computeroutput"><span class="identifier">char_type</span></code>'s
to be used as the replacement text, or either <code class="computeroutput"><span class="identifier">fmt</span><span class="special">(*</span><span class="keyword">this</span><span class="special">,</span>
<span class="identifier">out</span><span class="special">)</span></code>
or <code class="computeroutput"><span class="identifier">fmt</span><span class="special">(*</span><span class="keyword">this</span><span class="special">,</span> <span class="identifier">out</span><span class="special">,</span> <span class="identifier">flags</span><span class="special">)</span></code>, both of which write the replacement text
to <code class="computeroutput"><span class="special">*</span><span class="identifier">out</span></code>,
and then return the new OutputIterator position.
</p>
<p>
<span class="bold"><strong>Requires</strong></span>: that the match_results object
has been initialized as a result of a successful call to <a class="link" href="regex_search.html" title="regex_search"><code class="computeroutput"><span class="identifier">regex_search</span></code></a> or <a class="link" href="regex_match.html" title="regex_match"><code class="computeroutput"><span class="identifier">regex_match</span></code></a> or was returned from
a <a class="link" href="regex_iterator.html" title="regex_iterator"><code class="computeroutput"><span class="identifier">regex_iterator</span></code></a>,
and that the underlying iterators have not been subsequently invalidated.
Will raise a <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">logic_error</span></code> if the match_results object
was not initialized.
</p>
<p>
<span class="bold"><strong>Effects</strong></span>: If <code class="computeroutput"><span class="identifier">fmt</span></code>
is either a null-terminated string, or a container of <code class="computeroutput"><span class="identifier">char_type</span></code>'s,
then copies the string <span class="emphasis"><em>fmt</em></span>: For each format specifier
or escape sequence in <span class="emphasis"><em>fmt</em></span>, replace that sequence with
either the character(s) it represents, or the sequence of characters within
<code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code>
to which it refers. The bitmasks specified in flags determines what format
specifiers or escape sequences are recognized, by default this is the format
used by ECMA-262, ECMAScript Language Specification, Chapter 15 part 5.4.11
String.prototype.replace.
</p>
<p>
If <code class="computeroutput"><span class="identifier">fmt</span></code> is a function object,
then depending on the number of arguments the function object accepts, it
will either:
</p>
<div class="itemizedlist"><ul type="disc">
<li>
Call <code class="computeroutput"><span class="identifier">fmt</span><span class="special">(*</span><span class="keyword">this</span><span class="special">)</span></code>
and return the result.
</li>
<li>
Call <code class="computeroutput"><span class="identifier">fmt</span><span class="special">(*</span><span class="keyword">this</span><span class="special">,</span> <span class="identifier">unspecified</span><span class="special">-</span><span class="identifier">output</span><span class="special">-</span><span class="identifier">iterator</span><span class="special">)</span></code>,
where <code class="computeroutput"><span class="identifier">unspecified</span><span class="special">-</span><span class="identifier">output</span><span class="special">-</span><span class="identifier">iterator</span></code> is an unspecified OutputIterator
type used to copy the output to the string result.
</li>
<li>
Call <code class="computeroutput"><span class="identifier">fmt</span><span class="special">(*</span><span class="keyword">this</span><span class="special">,</span> <span class="identifier">unspecified</span><span class="special">-</span><span class="identifier">output</span><span class="special">-</span><span class="identifier">iterator</span><span class="special">,</span>
<span class="identifier">flags</span><span class="special">)</span></code>,
where <code class="computeroutput"><span class="identifier">unspecified</span><span class="special">-</span><span class="identifier">output</span><span class="special">-</span><span class="identifier">iterator</span></code> is an unspecified OutputIterator
type used to copy the output to the string result.
</li>
</ul></div>
<p>
See the <a class="link" href="../format.html" title="Search and Replace Format String Syntax">format syntax guide for more information</a>.
</p>
<a name="boost_regex.match_results.get_allocator"></a><p>
</p>
<pre class="programlisting"><span class="identifier">allocator_type</span> <span class="identifier">get_allocator</span><span class="special">()</span><span class="keyword">const</span><span class="special">;</span>
</pre>
<p>
<span class="bold"><strong>Effects</strong></span>: Returns a copy of the Allocator
that was passed to the object's constructor.
</p>
<a name="boost_regex.match_results.swap"></a><p>
</p>
<pre class="programlisting"><span class="keyword">void</span> <span class="identifier">swap</span><span class="special">(</span><span class="identifier">match_results</span><span class="special">&</span> <span class="identifier">that</span><span class="special">);</span>
</pre>
<p>
<span class="bold"><strong>Effects</strong></span>: Swaps the contents of the two sequences.
</p>
<p>
<span class="bold"><strong>Postcondition</strong></span>: *this contains the sequence
of matched sub-expressions that were in that, that contains the sequence
of matched sub-expressions that were in *this.
</p>
<p>
<span class="bold"><strong>Complexity</strong></span>: constant time.
</p>
<a name="boost_regex.match_results.capture_type"></a><p>
</p>
<pre class="programlisting"><span class="keyword">typedef</span> <span class="keyword">typename</span> <span class="identifier">value_type</span><span class="special">::</span><span class="identifier">capture_sequence_type</span> <span class="identifier">capture_sequence_type</span><span class="special">;</span>
</pre>
<p>
Defines an implementation-specific type that satisfies the requirements of
a standard library Sequence (21.1.1 including the optional Table 68 operations),
whose value_type is a <code class="computeroutput"><span class="identifier">sub_match</span><span class="special"><</span><span class="identifier">BidirectionalIterator</span><span class="special">></span></code>. This type happens to be <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">vector</span><span class="special"><</span><span class="identifier">sub_match</span><span class="special"><</span><span class="identifier">BidirectionalIterator</span><span class="special">></span> <span class="special">></span></code>,
but you shouldn't actually rely on that.
</p>
<a name="boost_regex.match_results.captures"></a><p>
</p>
<pre class="programlisting"><span class="keyword">const</span> <span class="identifier">capture_sequence_type</span><span class="special">&</span> <span class="identifier">captures</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">i</span><span class="special">)</span><span class="keyword">const</span><span class="special">;</span>
</pre>
<p>
<span class="bold"><strong>Requires</strong></span>: that the match_results object
has been initialized as a result of a successful call to <a class="link" href="regex_search.html" title="regex_search"><code class="computeroutput"><span class="identifier">regex_search</span></code></a> or <a class="link" href="regex_match.html" title="regex_match"><code class="computeroutput"><span class="identifier">regex_match</span></code></a> or was returned from
a <a class="link" href="regex_iterator.html" title="regex_iterator"><code class="computeroutput"><span class="identifier">regex_iterator</span></code></a>,
and that the underlying iterators have not been subsequently invalidated.
Will raise a <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">logic_error</span></code> if the match_results object
was not initialized.
</p>
<p>
<span class="bold"><strong>Effects</strong></span>: returns a sequence containing all
the captures obtained for sub-expression i.
</p>
<p>
<span class="bold"><strong>Returns</strong></span>: <code class="computeroutput"><span class="special">(*</span><span class="keyword">this</span><span class="special">)[</span><span class="identifier">i</span><span class="special">].</span><span class="identifier">captures</span><span class="special">();</span></code>
</p>
<p>
<span class="bold"><strong>Preconditions</strong></span>: the library must be built
and used with BOOST_REGEX_MATCH_EXTRA defined, and you must pass the flag
match_extra to the regex matching functions ( <a class="link" href="regex_match.html" title="regex_match"><code class="computeroutput"><span class="identifier">regex_match</span></code></a>, <a class="link" href="regex_search.html" title="regex_search"><code class="computeroutput"><span class="identifier">regex_search</span></code></a>, <a class="link" href="regex_iterator.html" title="regex_iterator"><code class="computeroutput"><span class="identifier">regex_iterator</span></code></a> or <a class="link" href="regex_token_iterator.html" title="regex_token_iterator"><code class="computeroutput"><span class="identifier">regex_token_iterator</span></code></a>) in order for
this member function to be defined and return useful information.
</p>
<p>
<span class="bold"><strong>Rationale</strong></span>: Enabling this feature has several
consequences:
</p>
<div class="itemizedlist"><ul type="disc">
<li>
sub_match occupies more memory resulting in complex expressions running
out of memory or stack space more quickly during matching.
</li>
<li>
The matching algorithms are less efficient at handling some features
(independent sub-expressions for example), even when match_extra is not
used.
</li>
<li>
The matching algorithms are much less efficient (i.e. slower), when match_extra
is used. Mostly this is down to the extra memory allocations that have
to take place.
</li>
</ul></div>
<a name="boost_regex.match_results.op_eq"></a><p>
</p>
<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> <span class="keyword">class</span> <span class="identifier">Allocator</span><span class="special">></span>
<span class="keyword">bool</span> <span class="keyword">operator</span> <span class="special">==</span> <span class="special">(</span><span class="keyword">const</span> <span class="identifier">match_results</span><span class="special"><</span><span class="identifier">BidirectionalIterator</span><span class="special">,</span> <span class="identifier">Allocator</span><span class="special">>&</span> <span class="identifier">m1</span><span class="special">,</span>
<span class="keyword">const</span> <span class="identifier">match_results</span><span class="special"><</span><span class="identifier">BidirectionalIterator</span><span class="special">,</span> <span class="identifier">Allocator</span><span class="special">>&</span> <span class="identifier">m2</span><span class="special">);</span>
</pre>
<p>
<span class="bold"><strong>Effects</strong></span>: Compares the two sequences for
equality.
</p>
<a name="boost_regex.match_results.op_ne"></a><p>
</p>
<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> <span class="keyword">class</span> <span class="identifier">Allocator</span><span class="special">></span>
<span class="keyword">bool</span> <span class="keyword">operator</span> <span class="special">!=</span> <span class="special">(</span><span class="keyword">const</span> <span class="identifier">match_results</span><span class="special"><</span><span class="identifier">BidirectionalIterator</span><span class="special">,</span> <span class="identifier">Allocator</span><span class="special">>&</span> <span class="identifier">m1</span><span class="special">,</span>
<span class="keyword">const</span> <span class="identifier">match_results</span><span class="special"><</span><span class="identifier">BidirectionalIterator</span><span class="special">,</span> <span class="identifier">Allocator</span><span class="special">>&</span> <span class="identifier">m2</span><span class="special">);</span>
</pre>
<p>
<span class="bold"><strong>Effects</strong></span>: Compares the two sequences for
inequality.
</p>
<a name="boost_regex.match_results.op_stream"></a><p>
</p>
<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> <span class="keyword">class</span> <span class="identifier">BidirectionalIterator</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">Allocator</span><span class="special">></span>
<span class="identifier">basic_ostream</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="keyword">operator</span> <span class="special"><<</span> <span class="special">(</span><span class="identifier">basic_ostream</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">os</span><span class="special">,</span>
<span class="keyword">const</span> <span class="identifier">match_results</span><span class="special"><</span><span class="identifier">BidirectionalIterator</span><span class="special">,</span> <span class="identifier">Allocator</span><span class="special">>&</span> <span class="identifier">m</span><span class="special">);</span>
</pre>
<p>
<span class="bold"><strong>Effects</strong></span>: Writes the contents of <span class="emphasis"><em>m</em></span>
to the stream <span class="emphasis"><em>os</em></span> as if by calling <code class="computeroutput"><span class="identifier">os</span>
<span class="special"><<</span> <span class="identifier">m</span><span class="special">.</span><span class="identifier">str</span><span class="special">()</span></code>;
Returns <span class="emphasis"><em>os</em></span>.
</p>
<a name="boost_regex.match_results.op_swap"></a><p>
</p>
<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> <span class="keyword">class</span> <span class="identifier">Allocator</span><span class="special">></span>
<span class="keyword">void</span> <span class="identifier">swap</span><span class="special">(</span><span class="identifier">match_results</span><span class="special"><</span><span class="identifier">BidirectionalIterator</span><span class="special">,</span> <span class="identifier">Allocator</span><span class="special">>&</span> <span class="identifier">m1</span><span class="special">,</span>
<span class="identifier">match_results</span><span class="special"><</span><span class="identifier">BidirectionalIterator</span><span class="special">,</span> <span class="identifier">Allocator</span><span class="special">>&</span> <span class="identifier">m2</span><span class="special">);</span>
</pre>
<p>
<span class="bold"><strong>Effects</strong></span>: Swaps the contents of the two sequences.
</p>
</div>
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<td align="right"><div class="copyright-footer">Copyright © 1998 -2007 John Maddock<p>
Distributed under the Boost Software License, Version 1.0. (See accompanying
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>)
</p>
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