forked from boostorg/regex
Add checked constructors to the Unicode iterators that need them.
Update icu support code to use the new checking-constructors. Update tests to check the full Unicode character range (as of Unicode V6). Add minimal docs describing the iterators. [SVN r73271]
This commit is contained in:
John Maddock
@ -3,7 +3,7 @@
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<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
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<title>Partial Matches</title>
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<div class="section" lang="en">
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<div class="section">
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<div class="titlepage"><div><div><h2 class="title" style="clear: both">
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<a name="boost_regex.partial_matches"></a><a class="link" href="partial_matches.html" title="Partial Matches">Partial Matches</a>
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</h2></div></div></div>
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@ -164,14 +164,14 @@
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Be aware that using partial matches can sometimes result in somewhat imperfect
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behavior:
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</p>
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<div class="itemizedlist"><ul type="disc">
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<li>
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<div class="itemizedlist"><ul class="itemizedlist" type="disc">
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<li class="listitem">
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There are some expressions, such as ".*abc" that will always
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produce a partial match. This problem can be reduced by careful construction
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of the regular expressions used, or by setting flags like match_not_dot_newline
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so that expressions like .* can't match past line boundaries.
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</li>
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<li>
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<li class="listitem">
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Boost.Regex currently prefers leftmost matches to full matches, so for
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example matching "abc|b" against "ab" produces a partial
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match against the "ab" rather than a full match against "b".
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@ -198,24 +198,24 @@
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<span class="keyword">bool</span> <span class="identifier">is_possible_card_number</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">&</span> <span class="identifier">input</span><span class="special">)</span>
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<span class="special">{</span>
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<span class="comment">//
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</span> <span class="comment">// return false for partial match, true for full match, or throw for
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</span> <span class="comment">// impossible match based on what we have so far...
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</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>
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<span class="comment">//</span>
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<span class="comment">// return false for partial match, true for full match, or throw for</span>
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<span class="comment">// impossible match based on what we have so far...</span>
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<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>
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<span class="keyword">if</span><span class="special">(</span><span class="number">0</span> <span class="special">==</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">regex_match</span><span class="special">(</span><span class="identifier">input</span><span class="special">,</span> <span class="identifier">what</span><span class="special">,</span> <span class="identifier">e</span><span class="special">,</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">match_default</span> <span class="special">|</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">match_partial</span><span class="special">))</span>
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<span class="special">{</span>
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<span class="comment">// the input so far could not possibly be valid so reject it:
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</span> <span class="keyword">throw</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">runtime_error</span><span class="special">(</span>
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<span class="comment">// the input so far could not possibly be valid so reject it:</span>
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<span class="keyword">throw</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">runtime_error</span><span class="special">(</span>
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<span class="string">"Invalid data entered - this could not possibly be a valid card number"</span><span class="special">);</span>
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<span class="special">}</span>
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<span class="comment">// OK so far so good, but have we finished?
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</span> <span class="keyword">if</span><span class="special">(</span><span class="identifier">what</span><span class="special">[</span><span class="number">0</span><span class="special">].</span><span class="identifier">matched</span><span class="special">)</span>
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<span class="comment">// OK so far so good, but have we finished?</span>
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<span class="keyword">if</span><span class="special">(</span><span class="identifier">what</span><span class="special">[</span><span class="number">0</span><span class="special">].</span><span class="identifier">matched</span><span class="special">)</span>
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<span class="special">{</span>
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<span class="comment">// excellent, we have a result:
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</span> <span class="keyword">return</span> <span class="keyword">true</span><span class="special">;</span>
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<span class="comment">// excellent, we have a result:</span>
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<span class="keyword">return</span> <span class="keyword">true</span><span class="special">;</span>
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<span class="special">}</span>
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<span class="comment">// what we have so far is only a partial match...
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</span> <span class="keyword">return</span> <span class="keyword">false</span><span class="special">;</span>
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<span class="comment">// what we have so far is only a partial match...</span>
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<span class="keyword">return</span> <span class="keyword">false</span><span class="special">;</span>
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<span class="special">}</span>
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</pre>
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<p>
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@ -231,37 +231,37 @@
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<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">string</span><span class="special">></span>
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<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>
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<span class="comment">// match some kind of html tag:
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</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">regex</span> <span class="identifier">e</span><span class="special">(</span><span class="string">"<[^>]*>"</span><span class="special">);</span>
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<span class="comment">// count how many:
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</span><span class="keyword">unsigned</span> <span class="keyword">int</span> <span class="identifier">tags</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span>
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<span class="comment">// match some kind of html tag:</span>
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<span class="identifier">boost</span><span class="special">::</span><span class="identifier">regex</span> <span class="identifier">e</span><span class="special">(</span><span class="string">"<[^>]*>"</span><span class="special">);</span>
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<span class="comment">// count how many:</span>
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<span class="keyword">unsigned</span> <span class="keyword">int</span> <span class="identifier">tags</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span>
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<span class="keyword">void</span> <span class="identifier">search</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>
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<span class="special">{</span>
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<span class="comment">// buffer we'll be searching in:
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</span> <span class="keyword">char</span> <span class="identifier">buf</span><span class="special">[</span><span class="number">4096</span><span class="special">];</span>
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<span class="comment">// saved position of end of partial match:
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</span> <span class="keyword">const</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">next_pos</span> <span class="special">=</span> <span class="identifier">buf</span> <span class="special">+</span> <span class="keyword">sizeof</span><span class="special">(</span><span class="identifier">buf</span><span class="special">);</span>
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<span class="comment">// flag to indicate whether there is more input to come:
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</span> <span class="keyword">bool</span> <span class="identifier">have_more</span> <span class="special">=</span> <span class="keyword">true</span><span class="special">;</span>
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<span class="comment">// buffer we'll be searching in:</span>
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<span class="keyword">char</span> <span class="identifier">buf</span><span class="special">[</span><span class="number">4096</span><span class="special">];</span>
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<span class="comment">// saved position of end of partial match:</span>
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<span class="keyword">const</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">next_pos</span> <span class="special">=</span> <span class="identifier">buf</span> <span class="special">+</span> <span class="keyword">sizeof</span><span class="special">(</span><span class="identifier">buf</span><span class="special">);</span>
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<span class="comment">// flag to indicate whether there is more input to come:</span>
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<span class="keyword">bool</span> <span class="identifier">have_more</span> <span class="special">=</span> <span class="keyword">true</span><span class="special">;</span>
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<span class="keyword">while</span><span class="special">(</span><span class="identifier">have_more</span><span class="special">)</span>
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<span class="special">{</span>
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<span class="comment">// how much do we copy forward from last try:
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</span> <span class="keyword">unsigned</span> <span class="identifier">leftover</span> <span class="special">=</span> <span class="special">(</span><span class="identifier">buf</span> <span class="special">+</span> <span class="keyword">sizeof</span><span class="special">(</span><span class="identifier">buf</span><span class="special">))</span> <span class="special">-</span> <span class="identifier">next_pos</span><span class="special">;</span>
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<span class="comment">// and how much is left to fill:
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</span> <span class="keyword">unsigned</span> <span class="identifier">size</span> <span class="special">=</span> <span class="identifier">next_pos</span> <span class="special">-</span> <span class="identifier">buf</span><span class="special">;</span>
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<span class="comment">// copy forward whatever we have left:
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</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">memmove</span><span class="special">(</span><span class="identifier">buf</span><span class="special">,</span> <span class="identifier">next_pos</span><span class="special">,</span> <span class="identifier">leftover</span><span class="special">);</span>
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<span class="comment">// fill the rest from the stream:
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</span> <span class="identifier">is</span><span class="special">.</span><span class="identifier">read</span><span class="special">(</span><span class="identifier">buf</span> <span class="special">+</span> <span class="identifier">leftover</span><span class="special">,</span> <span class="identifier">size</span><span class="special">);</span>
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<span class="comment">// how much do we copy forward from last try:</span>
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<span class="keyword">unsigned</span> <span class="identifier">leftover</span> <span class="special">=</span> <span class="special">(</span><span class="identifier">buf</span> <span class="special">+</span> <span class="keyword">sizeof</span><span class="special">(</span><span class="identifier">buf</span><span class="special">))</span> <span class="special">-</span> <span class="identifier">next_pos</span><span class="special">;</span>
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<span class="comment">// and how much is left to fill:</span>
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<span class="keyword">unsigned</span> <span class="identifier">size</span> <span class="special">=</span> <span class="identifier">next_pos</span> <span class="special">-</span> <span class="identifier">buf</span><span class="special">;</span>
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<span class="comment">// copy forward whatever we have left:</span>
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<span class="identifier">std</span><span class="special">::</span><span class="identifier">memmove</span><span class="special">(</span><span class="identifier">buf</span><span class="special">,</span> <span class="identifier">next_pos</span><span class="special">,</span> <span class="identifier">leftover</span><span class="special">);</span>
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<span class="comment">// fill the rest from the stream:</span>
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<span class="identifier">is</span><span class="special">.</span><span class="identifier">read</span><span class="special">(</span><span class="identifier">buf</span> <span class="special">+</span> <span class="identifier">leftover</span><span class="special">,</span> <span class="identifier">size</span><span class="special">);</span>
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<span class="keyword">unsigned</span> <span class="identifier">read</span> <span class="special">=</span> <span class="identifier">is</span><span class="special">.</span><span class="identifier">gcount</span><span class="special">();</span>
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<span class="comment">// check to see if we've run out of text:
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</span> <span class="identifier">have_more</span> <span class="special">=</span> <span class="identifier">read</span> <span class="special">==</span> <span class="identifier">size</span><span class="special">;</span>
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<span class="comment">// reset next_pos:
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</span> <span class="identifier">next_pos</span> <span class="special">=</span> <span class="identifier">buf</span> <span class="special">+</span> <span class="keyword">sizeof</span><span class="special">(</span><span class="identifier">buf</span><span class="special">);</span>
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<span class="comment">// and then iterate:
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</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">cregex_iterator</span> <span class="identifier">a</span><span class="special">(</span>
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<span class="comment">// check to see if we've run out of text:</span>
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<span class="identifier">have_more</span> <span class="special">=</span> <span class="identifier">read</span> <span class="special">==</span> <span class="identifier">size</span><span class="special">;</span>
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<span class="comment">// reset next_pos:</span>
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<span class="identifier">next_pos</span> <span class="special">=</span> <span class="identifier">buf</span> <span class="special">+</span> <span class="keyword">sizeof</span><span class="special">(</span><span class="identifier">buf</span><span class="special">);</span>
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<span class="comment">// and then iterate:</span>
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<span class="identifier">boost</span><span class="special">::</span><span class="identifier">cregex_iterator</span> <span class="identifier">a</span><span class="special">(</span>
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<span class="identifier">buf</span><span class="special">,</span>
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<span class="identifier">buf</span> <span class="special">+</span> <span class="identifier">read</span> <span class="special">+</span> <span class="identifier">leftover</span><span class="special">,</span>
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<span class="identifier">e</span><span class="special">,</span>
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@ -272,18 +272,18 @@
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<span class="special">{</span>
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<span class="keyword">if</span><span class="special">((*</span><span class="identifier">a</span><span class="special">)[</span><span class="number">0</span><span class="special">].</span><span class="identifier">matched</span> <span class="special">==</span> <span class="keyword">false</span><span class="special">)</span>
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<span class="special">{</span>
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<span class="comment">// Partial match, save position and break:
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</span> <span class="identifier">next_pos</span> <span class="special">=</span> <span class="special">(*</span><span class="identifier">a</span><span class="special">)[</span><span class="number">0</span><span class="special">].</span><span class="identifier">first</span><span class="special">;</span>
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<span class="comment">// Partial match, save position and break:</span>
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<span class="identifier">next_pos</span> <span class="special">=</span> <span class="special">(*</span><span class="identifier">a</span><span class="special">)[</span><span class="number">0</span><span class="special">].</span><span class="identifier">first</span><span class="special">;</span>
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<span class="keyword">break</span><span class="special">;</span>
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<span class="special">}</span>
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<span class="keyword">else</span>
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<span class="special">{</span>
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<span class="comment">// full match:
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</span> <span class="special">++</span><span class="identifier">tags</span><span class="special">;</span>
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<span class="comment">// full match:</span>
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<span class="special">++</span><span class="identifier">tags</span><span class="special">;</span>
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<span class="special">}</span>
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<span class="comment">// move to next match:
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</span> <span class="special">++</span><span class="identifier">a</span><span class="special">;</span>
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<span class="comment">// move to next match:</span>
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<span class="special">++</span><span class="identifier">a</span><span class="special">;</span>
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<span class="special">}</span>
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<span class="special">}</span>
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<span class="special">}</span>
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@ -291,7 +291,7 @@
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</div>
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<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
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<td align="left"></td>
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<td align="right"><div class="copyright-footer">Copyright © 1998 -2010 John Maddock<p>
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<td align="right"><div class="copyright-footer">Copyright © 1998-2010 John Maddock<p>
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Distributed under the Boost Software License, Version 1.0. (See accompanying
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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>)
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</p>
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