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| <div class="section"> |
| <div class="titlepage"><div><div><h4 class="title"> |
| <a name="spirit_repository.qi_components.directives.distinct"></a><a class="link" href="distinct.html" title="Qi Distinct Parser Directive"> |
| Qi Distinct Parser Directive</a> |
| </h4></div></div></div> |
| <a name="spirit_repository.qi_components.directives.distinct.description"></a><h6> |
| <a name="id764582"></a> |
| <a class="link" href="distinct.html#spirit_repository.qi_components.directives.distinct.description">Description</a> |
| </h6> |
| <p> |
| The <span class="emphasis"><em>Spirit.Qi</em></span> <code class="computeroutput"><span class="identifier">distinct</span></code> |
| parser is a directive component allowing to avoid partial matches while |
| parsing using a skipper. A simple example is the common task of matching |
| a C keyword. Consider: |
| </p> |
| <pre class="programlisting"><span class="string">"description"</span> <span class="special">>></span> <span class="special">-</span><span class="identifier">lit</span><span class="special">(</span><span class="string">":"</span><span class="special">)</span> <span class="special">>></span> <span class="special">*(</span><span class="identifier">char_</span> <span class="special">-</span> <span class="identifier">eol</span><span class="special">)</span> |
| </pre> |
| <p> |
| intended to match a line in a configuration file. Let's assume further, |
| that this rule is used with a <code class="computeroutput"><span class="identifier">space</span></code> |
| skipper and that we have the following strings in the input: |
| </p> |
| <pre class="programlisting"><span class="string">"description: ident\n"</span> |
| <span class="string">"description ident\n"</span> |
| <span class="string">"descriptionident\n"</span> |
| </pre> |
| <p> |
| It might seem unexpected, but the parser above matches all three inputs |
| just fine, even if the third input should not match at all! In order to |
| avoid the unwanted match we are forced to make our rule more complicated: |
| </p> |
| <pre class="programlisting"><span class="identifier">lexeme</span><span class="special">[</span><span class="string">"description"</span> <span class="special">>></span> <span class="special">!</span><span class="identifier">char_</span><span class="special">(</span><span class="string">"a-zA-Z_0-9"</span><span class="special">)]</span> <span class="special">>></span> <span class="special">-</span><span class="identifier">lit</span><span class="special">(</span><span class="string">":"</span><span class="special">)</span> <span class="special">>></span> <span class="special">*(</span><span class="identifier">char_</span> <span class="special">-</span> <span class="identifier">eol</span><span class="special">)</span> |
| </pre> |
| <p> |
| (the rule reads as: match <code class="computeroutput"><span class="string">"description"</span></code> |
| as long as it's not <span class="emphasis"><em>directly</em></span> followed by a valid identifier). |
| </p> |
| <p> |
| The <code class="computeroutput"><span class="identifier">distinct</span><span class="special">[]</span></code> |
| directive is meant to simplify the rule above: |
| </p> |
| <pre class="programlisting"><span class="identifier">distinct</span><span class="special">(</span><span class="identifier">char_</span><span class="special">(</span><span class="string">"a-zA-Z_0-9"</span><span class="special">))[</span><span class="string">"description"</span><span class="special">]</span> <span class="special">>></span> <span class="special">-</span><span class="identifier">lit</span><span class="special">(</span><span class="string">":"</span><span class="special">)</span> <span class="special">>></span> <span class="special">*(</span><span class="identifier">char_</span> <span class="special">-</span> <span class="identifier">eol</span><span class="special">)</span> |
| </pre> |
| <p> |
| Using the <code class="computeroutput"><span class="identifier">distinct</span><span class="special">[]</span></code> |
| component instead of the explicit sequence has the advantage of being able |
| to encapsulate the tail (i.e the <code class="computeroutput"><span class="identifier">char_</span><span class="special">(</span><span class="string">"a-zA-Z_0-9"</span><span class="special">)</span></code>) as a separate parser construct. The following |
| code snippet illustrates the idea (for the full code of this example please |
| see <a href="../../../../../test/qi/distinct.cpp" target="_top">distinct.cpp</a>): |
| </p> |
| <p> |
| |
| </p> |
| <pre class="programlisting"><span class="keyword">namespace</span> <span class="identifier">spirit</span> <span class="special">=</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">spirit</span><span class="special">;</span> |
| <span class="keyword">namespace</span> <span class="identifier">ascii</span> <span class="special">=</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">spirit</span><span class="special">::</span><span class="identifier">ascii</span><span class="special">;</span> |
| <span class="keyword">namespace</span> <span class="identifier">repo</span> <span class="special">=</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">spirit</span><span class="special">::</span><span class="identifier">repository</span><span class="special">;</span> |
| |
| <span class="comment">// Define metafunctions allowing to compute the type of the distinct() |
| </span><span class="comment">// and ascii::char_() constructs |
| </span><span class="keyword">namespace</span> <span class="identifier">traits</span> |
| <span class="special">{</span> |
| <span class="comment">// Metafunction allowing to get the type of any repository::distinct(...) |
| </span> <span class="comment">// construct |
| </span> <span class="keyword">template</span> <span class="special"><</span><span class="keyword">typename</span> <span class="identifier">Tail</span><span class="special">></span> |
| <span class="keyword">struct</span> <span class="identifier">distinct_spec</span> |
| <span class="special">:</span> <span class="identifier">spirit</span><span class="special">::</span><span class="identifier">result_of</span><span class="special">::</span><span class="identifier">terminal</span><span class="special"><</span><span class="identifier">repo</span><span class="special">::</span><span class="identifier">tag</span><span class="special">::</span><span class="identifier">distinct</span><span class="special">(</span><span class="identifier">Tail</span><span class="special">)></span> |
| <span class="special">{};</span> |
| |
| <span class="comment">// Metafunction allowing to get the type of any ascii::char_(...) construct |
| </span> <span class="keyword">template</span> <span class="special"><</span><span class="keyword">typename</span> <span class="identifier">String</span><span class="special">></span> |
| <span class="keyword">struct</span> <span class="identifier">char_spec</span> |
| <span class="special">:</span> <span class="identifier">spirit</span><span class="special">::</span><span class="identifier">result_of</span><span class="special">::</span><span class="identifier">terminal</span><span class="special"><</span><span class="identifier">spirit</span><span class="special">::</span><span class="identifier">tag</span><span class="special">::</span><span class="identifier">ascii</span><span class="special">::</span><span class="identifier">char_</span><span class="special">(</span><span class="identifier">String</span><span class="special">)></span> |
| <span class="special">{};</span> |
| <span class="special">};</span> |
| |
| <span class="comment">// Define a helper function allowing to create a distinct() construct from |
| </span><span class="comment">// an arbitrary tail parser |
| </span><span class="keyword">template</span> <span class="special"><</span><span class="keyword">typename</span> <span class="identifier">Tail</span><span class="special">></span> |
| <span class="keyword">inline</span> <span class="keyword">typename</span> <span class="identifier">traits</span><span class="special">::</span><span class="identifier">distinct_spec</span><span class="special"><</span><span class="identifier">Tail</span><span class="special">>::</span><span class="identifier">type</span> |
| <span class="identifier">distinct_spec</span><span class="special">(</span><span class="identifier">Tail</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">tail</span><span class="special">)</span> |
| <span class="special">{</span> |
| <span class="keyword">return</span> <span class="identifier">repo</span><span class="special">::</span><span class="identifier">distinct</span><span class="special">(</span><span class="identifier">tail</span><span class="special">);</span> |
| <span class="special">}</span> |
| |
| <span class="comment">// Define a helper function allowing to create a ascii::char_() construct |
| </span><span class="comment">// from an arbitrary string representation |
| </span><span class="keyword">template</span> <span class="special"><</span><span class="keyword">typename</span> <span class="identifier">String</span><span class="special">></span> |
| <span class="keyword">inline</span> <span class="keyword">typename</span> <span class="identifier">traits</span><span class="special">::</span><span class="identifier">char_spec</span><span class="special"><</span><span class="identifier">String</span><span class="special">>::</span><span class="identifier">type</span> |
| <span class="identifier">char_spec</span><span class="special">(</span><span class="identifier">String</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">str</span><span class="special">)</span> |
| <span class="special">{</span> |
| <span class="keyword">return</span> <span class="identifier">ascii</span><span class="special">::</span><span class="identifier">char_</span><span class="special">(</span><span class="identifier">str</span><span class="special">);</span> |
| <span class="special">}</span> |
| |
| <span class="comment">// the following constructs the type of a distinct_spec holding a |
| </span><span class="comment">// charset("0-9a-zA-Z_") as its tail parser |
| </span><span class="keyword">typedef</span> <span class="identifier">traits</span><span class="special">::</span><span class="identifier">char_spec</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">type</span> <span class="identifier">charset_tag_type</span><span class="special">;</span> |
| <span class="keyword">typedef</span> <span class="identifier">traits</span><span class="special">::</span><span class="identifier">distinct_spec</span><span class="special"><</span><span class="identifier">charset_tag_type</span><span class="special">>::</span><span class="identifier">type</span> <span class="identifier">keyword_tag_type</span><span class="special">;</span> |
| |
| <span class="comment">// Define a new Qi 'keyword' directive usable as a shortcut for a |
| </span><span class="comment">// repository::distinct(char_(std::string("0-9a-zA-Z_"))) |
| </span><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span> <span class="keyword">const</span> <span class="identifier">keyword_spec</span><span class="special">(</span><span class="string">"0-9a-zA-Z_"</span><span class="special">);</span> |
| <span class="identifier">keyword_tag_type</span> <span class="keyword">const</span> <span class="identifier">keyword</span> <span class="special">=</span> <span class="identifier">distinct_spec</span><span class="special">(</span><span class="identifier">char_spec</span><span class="special">(</span><span class="identifier">keyword_spec</span><span class="special">));</span> |
| </pre> |
| <p> |
| </p> |
| <p> |
| These definitions define a new Qi parser recognizing keywords! This allows |
| to rewrite our declaration parser expression as: |
| </p> |
| <pre class="programlisting"><span class="identifier">keyword</span><span class="special">[</span><span class="string">"description"</span><span class="special">]</span> <span class="special">>></span> <span class="special">-</span><span class="identifier">lit</span><span class="special">(</span><span class="string">":"</span><span class="special">)</span> <span class="special">>></span> <span class="special">*(</span><span class="identifier">char_</span> <span class="special">-</span> <span class="identifier">eol</span><span class="special">)</span> |
| </pre> |
| <p> |
| which is much more readable and concise if compared to the original parser |
| expression. In addition the new <code class="computeroutput"><span class="identifier">keyword</span><span class="special">[]</span></code> directive has the advantage to be usable |
| for wrapping any parser expression, not only strings as in the example |
| above. |
| </p> |
| <a name="spirit_repository.qi_components.directives.distinct.header"></a><h6> |
| <a name="id765952"></a> |
| <a class="link" href="distinct.html#spirit_repository.qi_components.directives.distinct.header">Header</a> |
| </h6> |
| <pre class="programlisting"><span class="comment">// forwards to <boost/spirit/repository/home/qi/directive/distinct.hpp> |
| </span><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">spirit</span><span class="special">/</span><span class="identifier">repository</span><span class="special">/</span><span class="identifier">include</span><span class="special">/</span><span class="identifier">qi_distinct</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> |
| </pre> |
| <a name="spirit_repository.qi_components.directives.distinct.synopsis"></a><h6> |
| <a name="id766039"></a> |
| <a class="link" href="distinct.html#spirit_repository.qi_components.directives.distinct.synopsis">Synopsis</a> |
| </h6> |
| <pre class="programlisting"><span class="identifier">distinct</span><span class="special">(</span><span class="identifier">tail</span><span class="special">)[</span><span class="identifier">subject</span><span class="special">]</span> |
| </pre> |
| <a name="spirit_repository.qi_components.directives.distinct.parameters"></a><h6> |
| <a name="id766087"></a> |
| <a class="link" href="distinct.html#spirit_repository.qi_components.directives.distinct.parameters">Parameters</a> |
| </h6> |
| <div class="informaltable"><table class="table"> |
| <colgroup> |
| <col> |
| <col> |
| </colgroup> |
| <thead><tr> |
| <th> |
| <p> |
| Parameter |
| </p> |
| </th> |
| <th> |
| <p> |
| Description |
| </p> |
| </th> |
| </tr></thead> |
| <tbody> |
| <tr> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">tail</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| The parser construct specifying what whould not follow the subject |
| in order to match the overall expression. |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">subject</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| The parser construct to use to match the current input. The distinct |
| directive makes sure that no unexpected partial matches occur. |
| </p> |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| <p> |
| All two parameters can be arbitrary complex parsers themselves. |
| </p> |
| <a name="spirit_repository.qi_components.directives.distinct.attribute"></a><h6> |
| <a name="id766199"></a> |
| <a class="link" href="distinct.html#spirit_repository.qi_components.directives.distinct.attribute">Attribute</a> |
| </h6> |
| <p> |
| The <code class="computeroutput"><span class="identifier">distinct</span></code> component |
| exposes the attribute type of its subject as its own attribute type. If |
| the <code class="computeroutput"><span class="identifier">subject</span></code> does not expose |
| any attribute (the type is <code class="computeroutput"><span class="identifier">unused_type</span></code>), |
| then the <code class="computeroutput"><span class="identifier">distinct</span></code> does |
| not expose any attribute either. |
| </p> |
| <pre class="programlisting"><span class="identifier">a</span><span class="special">:</span> <span class="identifier">A</span><span class="special">,</span> <span class="identifier">b</span><span class="special">:</span> <span class="identifier">B</span> <span class="special">--></span> <span class="identifier">distinct</span><span class="special">(</span><span class="identifier">b</span><span class="special">)[</span><span class="identifier">a</span><span class="special">]:</span> <span class="identifier">A</span> |
| </pre> |
| <a name="spirit_repository.qi_components.directives.distinct.example"></a><h6> |
| <a name="id766328"></a> |
| <a class="link" href="distinct.html#spirit_repository.qi_components.directives.distinct.example">Example</a> |
| </h6> |
| <p> |
| The following example shows simple use cases of the <code class="computeroutput"><span class="identifier">distinct</span></code> |
| parser. <a href="../../../../../example/qi/distinct.cpp" target="_top">distinct.cpp</a>) |
| </p> |
| <a name="spirit_repository.qi_components.directives.distinct.prerequisites"></a><h6> |
| <a name="id766365"></a> |
| <a class="link" href="distinct.html#spirit_repository.qi_components.directives.distinct.prerequisites">Prerequisites</a> |
| </h6> |
| <p> |
| In addition to the main header file needed to include the core components |
| implemented in <span class="emphasis"><em>Spirit.Qi</em></span> we add the header file needed |
| for the new <code class="computeroutput"><span class="identifier">distinct</span></code> generator. |
| </p> |
| <p> |
| |
| </p> |
| <pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">spirit</span><span class="special">/</span><span class="identifier">include</span><span class="special">/</span><span class="identifier">qi</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> |
| <span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">spirit</span><span class="special">/</span><span class="identifier">repository</span><span class="special">/</span><span class="identifier">include</span><span class="special">/</span><span class="identifier">qi_distinct</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> |
| </pre> |
| <p> |
| </p> |
| <p> |
| To make all the code below more readable we introduce the following namespaces. |
| </p> |
| <p> |
| |
| </p> |
| <pre class="programlisting"><span class="keyword">using</span> <span class="keyword">namespace</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">spirit</span><span class="special">;</span> |
| <span class="keyword">using</span> <span class="keyword">namespace</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">spirit</span><span class="special">::</span><span class="identifier">ascii</span><span class="special">;</span> |
| <span class="keyword">using</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">spirit</span><span class="special">::</span><span class="identifier">repository</span><span class="special">::</span><span class="identifier">distinct</span><span class="special">;</span> |
| </pre> |
| <p> |
| </p> |
| <a name="spirit_repository.qi_components.directives.distinct.using_the_distinct_directive_to_match_keywords"></a><h6> |
| <a name="id766632"></a> |
| <a class="link" href="distinct.html#spirit_repository.qi_components.directives.distinct.using_the_distinct_directive_to_match_keywords">Using |
| The Distinct Directive to Match keywords</a> |
| </h6> |
| <p> |
| We show several examples of how the <code class="computeroutput"><span class="identifier">distinct</span><span class="special">[]</span></code> directive can be used to force correct |
| behavior while matching keywords. The first two code snippets show the |
| correct matching of the <code class="computeroutput"><span class="identifier">description</span></code> |
| keyword (in this hypothetical example we allow keywords to be directly |
| followed by an optional <code class="computeroutput"><span class="string">"--"</span></code>): |
| </p> |
| <p> |
| |
| </p> |
| <pre class="programlisting"><span class="special">{</span> |
| <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span> <span class="identifier">str</span><span class="special">(</span><span class="string">"description ident"</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">iterator</span> <span class="identifier">first</span><span class="special">(</span><span class="identifier">str</span><span class="special">.</span><span class="identifier">begin</span><span class="special">());</span> |
| <span class="keyword">bool</span> <span class="identifier">r</span> <span class="special">=</span> <span class="identifier">qi</span><span class="special">::</span><span class="identifier">phrase_parse</span><span class="special">(</span><span class="identifier">first</span><span class="special">,</span> <span class="identifier">str</span><span class="special">.</span><span class="identifier">end</span><span class="special">()</span> |
| <span class="special">,</span> <span class="identifier">distinct</span><span class="special">(</span><span class="identifier">alnum</span> <span class="special">|</span> <span class="char">'_'</span><span class="special">)[</span><span class="string">"description"</span><span class="special">]</span> <span class="special">>></span> <span class="special">-</span><span class="identifier">lit</span><span class="special">(</span><span class="string">"--"</span><span class="special">)</span> <span class="special">>></span> <span class="special">+(</span><span class="identifier">alnum</span> <span class="special">|</span> <span class="char">'_'</span><span class="special">)</span> |
| <span class="special">,</span> <span class="identifier">space</span><span class="special">);</span> |
| <span class="identifier">BOOST_ASSERT</span><span class="special">(</span><span class="identifier">r</span> <span class="special">&&</span> <span class="identifier">first</span> <span class="special">==</span> <span class="identifier">str</span><span class="special">.</span><span class="identifier">end</span><span class="special">());</span> |
| <span class="special">}</span> |
| </pre> |
| <p> |
| </p> |
| <p> |
| |
| </p> |
| <pre class="programlisting"><span class="special">{</span> |
| <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span> <span class="identifier">str</span><span class="special">(</span><span class="string">"description--ident"</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">iterator</span> <span class="identifier">first</span><span class="special">(</span><span class="identifier">str</span><span class="special">.</span><span class="identifier">begin</span><span class="special">());</span> |
| <span class="keyword">bool</span> <span class="identifier">r</span> <span class="special">=</span> <span class="identifier">qi</span><span class="special">::</span><span class="identifier">phrase_parse</span><span class="special">(</span><span class="identifier">first</span><span class="special">,</span> <span class="identifier">str</span><span class="special">.</span><span class="identifier">end</span><span class="special">()</span> |
| <span class="special">,</span> <span class="identifier">distinct</span><span class="special">(</span><span class="identifier">alnum</span> <span class="special">|</span> <span class="char">'_'</span><span class="special">)[</span><span class="string">"description"</span><span class="special">]</span> <span class="special">>></span> <span class="special">-</span><span class="identifier">lit</span><span class="special">(</span><span class="string">"--"</span><span class="special">)</span> <span class="special">>></span> <span class="special">+(</span><span class="identifier">alnum</span> <span class="special">|</span> <span class="char">'_'</span><span class="special">)</span> |
| <span class="special">,</span> <span class="identifier">space</span><span class="special">);</span> |
| <span class="identifier">BOOST_ASSERT</span><span class="special">(</span><span class="identifier">r</span> <span class="special">&&</span> <span class="identifier">first</span> <span class="special">==</span> <span class="identifier">str</span><span class="special">.</span><span class="identifier">end</span><span class="special">());</span> |
| <span class="special">}</span> |
| </pre> |
| <p> |
| </p> |
| <p> |
| The last example shows that the <code class="computeroutput"><span class="identifier">distinct</span><span class="special">[]</span></code> parser component correctly refuses to |
| match "description-ident": |
| </p> |
| <p> |
| |
| </p> |
| <pre class="programlisting"><span class="special">{</span> |
| <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span> <span class="identifier">str</span><span class="special">(</span><span class="string">"description-ident"</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">iterator</span> <span class="identifier">first</span><span class="special">(</span><span class="identifier">str</span><span class="special">.</span><span class="identifier">begin</span><span class="special">());</span> |
| <span class="keyword">bool</span> <span class="identifier">r</span> <span class="special">=</span> <span class="identifier">qi</span><span class="special">::</span><span class="identifier">phrase_parse</span><span class="special">(</span><span class="identifier">first</span><span class="special">,</span> <span class="identifier">str</span><span class="special">.</span><span class="identifier">end</span><span class="special">()</span> |
| <span class="special">,</span> <span class="identifier">distinct</span><span class="special">(</span><span class="identifier">alnum</span> <span class="special">|</span> <span class="char">'_'</span><span class="special">)[</span><span class="string">"description"</span><span class="special">]</span> <span class="special">>></span> <span class="special">-</span><span class="identifier">lit</span><span class="special">(</span><span class="string">"--"</span><span class="special">)</span> <span class="special">>></span> <span class="special">+(</span><span class="identifier">alnum</span> <span class="special">|</span> <span class="char">'_'</span><span class="special">)</span> |
| <span class="special">,</span> <span class="identifier">space</span><span class="special">);</span> |
| <span class="identifier">BOOST_ASSERT</span><span class="special">(!</span><span class="identifier">r</span> <span class="special">&&</span> <span class="identifier">first</span> <span class="special">==</span> <span class="identifier">str</span><span class="special">.</span><span class="identifier">begin</span><span class="special">());</span> |
| <span class="special">}</span> |
| </pre> |
| <p> |
| </p> |
| </div> |
| <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> |
| <td align="left"></td> |
| <td align="right"><div class="copyright-footer">Copyright © 2001-2010 Joel de Guzman, Hartmut Kaiser<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> |
| </div></td> |
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