| <html> |
| <head> |
| <!-- Generated by the Spirit (http://spirit.sf.net) QuickDoc --> |
| <title>predefined_actors</title> |
| <link rel="stylesheet" href="theme/style.css" type="text/css"> |
| </head> |
| <body> |
| <table width="100%" height="48" border="0" background="theme/bkd2.gif" cellspacing="2"> |
| <tr> |
| <td width="10"> |
| </td> |
| <td width="85%"> <font size="6" face="Verdana, Arial, Helvetica, sans-serif"><b>Predefined |
| Actors</b></font></td> |
| <td width="112"><a href="http://spirit.sf.net"><img src="theme/spirit.gif" align="right" border="0"></a></td> |
| </tr> |
| </table> |
| <br> |
| <table border="0"> |
| <tr> |
| <td width="30"><a href="../index.html"><img src="theme/u_arr.gif" border="0"></a></td> |
| <td width="30"><a href="indepth_the_parser_context.html"><img src="theme/l_arr.gif" width="20" height="19" border="0"></a></td> |
| <td width="20"><a href="parametric_parsers.html"><img src="theme/r_arr.gif" width="20" height="19" border="0"></a></td> |
| </tr> |
| </table> |
| <h2>Actors</h2><p> |
| The framework has a number of predefined semantic action functors. |
| Experience shows that these functors are so often used that they were included |
| as part of the core framework to spare the user from having to reinvent the |
| same functionality over and over again.</p> |
| <h2>Quick example: <tt>assign_a</tt> actor</h2> |
| <code> |
| <pre> <span class=keyword>int </span><span class=identifier>i</span><span class=special>,</span><span class=identifier> j</span><span class=special>; |
| </span><span class=identifier>std</span><span class=special>::</span><span class=identifier>string </span><span class=identifier>s</span><span class=special>; |
| </span><span class=identifier>r </span><span class=special>= </span><span class=identifier>int_p</span><span class=special>[</span><span class=identifier>assign_a</span><span class=special>(</span><span class=identifier>i</span><span class=special>)] >> (+</span><span class=identifier>alpha_p</span><span class=special>)[</span><span class=identifier>assign_a</span><span class=special>(</span><span class=identifier>s</span><span class=special>)] >> </span><span class=identifier>int_p</span><span class=special>[</span><span class=identifier>assign_a</span><span class=special>(</span><span class=identifier>j</span><span class=special>,</span><span class=identifier>i</span><span class=special>)];</span></pre> |
| </code> |
| <p> |
| Given an input <tt>123456 Hello 789</tt>, </p> |
| <ol><li><tt>assign_a(i)</tt> will extract the number <tt>123456</tt> and assign it to <tt>i</tt>, </li><li><tt>assign_a(s)</tt> will extract the string <tt>"Hello"</tt> and assign it to <tt>s</tt>,</li><li><tt>assign_a(j,i)</tt> will assign i to j, j=i, without using the parse result.</li></ol> |
| <p> Technically, the expression <tt>assign_a(v)</tt> is a template function that |
| generates a semantic action. In fact, actor instances are not created directly |
| since they usually involve a number of template parameters. Instead generator |
| functions ("helper functions") are provided to generate actors from |
| their arguments. All helper functions have the "_a" suffix. For example, |
| <tt>append_actor</tt> is created using the <tt>append_a</tt> function. </p> |
| <p> |
| The semantic action generated is polymorphic and should work with any |
| type as long as it is compatible with the arguments received from the parser. |
| It might not be obvious, but a string can accept the iterator first and last |
| arguments that are passed into a generic semantic action (see above). In fact, |
| any STL container that has an <tt>assign(first, last)</tt> member function can be |
| used.</p> |
| <h2>Actors summary</h2><p> |
| Below are tables summarizing the "built-in" actors with the |
| conventions given below.</p> |
| <ul> |
| <li><tt>ref</tt> is a <b>reference</b> to an object stored in a policy holder |
| actor</li> |
| <li><tt>value_ref</tt> and <tt>key_ref</tt> are <b>const reference</b>s stored |
| in a policy holder actor</li> |
| <li><tt>value</tt> is the <b>parse result</b>. This could be the result for |
| the single argument () operator or the two argument () operator</li> |
| <li><tt>vt</tt> stands for the <tt>value_type</tt> type: <tt>type& ref; |
| // vt is type::value_type</tt>.</li> |
| </ul> |
| <p> Note that examples are provided after the tables.</p> |
| <table width="90%" border="0" align="center"> |
| <tr> |
| <td class="table_title" colspan="8"> Unary operator actors</td> |
| </tr> |
| <td width="30%" class="table_cells">++ref</td> <td width="70%" class="table_cells"><b>increment_a</b>(ref)</td> |
| </tr> |
| <td class="table_cells">--ref</td> <td class="table_cells"><b>decrement_a</b>(ref)</td> |
| </tr> |
| </table> |
| <table width="90%" border="0" align="center"> |
| <tr> |
| <td class="table_title" colspan="26"> Assign actors</td> |
| </tr> |
| <tr> |
| <td class="table_cells">ref = value</td> |
| <td class="table_cells"><b>assign_a</b>(ref)</td> |
| </tr> |
| <td width="30%" class="table_cells">ref = value_ref</td> |
| <td width="70%" class="table_cells"><b>assign_a</b>(ref, value_ref)</td> |
| </tr> |
| </table> |
| <table width="90%" border="0" align="center"> |
| <tr> |
| <td class="table_title" colspan="30"> Container actors </td> |
| </tr> |
| <tr> |
| <td width="30%" class="table_cells">ref.push_back(value)</td> |
| <td width="70%" class="table_cells"><b>push_back_a</b>(ref)</td> |
| </tr> |
| <td class="table_cells">ref.push_back(value_ref)</td> |
| <td class="table_cells"><b>push_back_a</b>(ref, value_ref)</td> |
| </tr> |
| <td class="table_cells">ref.push_front(value)</td> |
| <td class="table_cells"><b>push_front_a</b>(ref)</td> |
| </tr> |
| <td class="table_cells">ref.push_front(value_ref)</td> |
| <td class="table_cells"><b>push_front_a</b>(ref, value_ref)</td> |
| </tr> |
| <td class="table_cells">ref.clear()</td> |
| <td class="table_cells"><b>clear_a</b>(ref)</td> |
| </tr> |
| </table> |
| <table width="90%" border="0" align="center"> |
| <tr> |
| <td class="table_title" colspan="14"> Associative container actors </td> |
| </tr> |
| <td width="30%" class="table_cells">ref.insert(vt(value, value_ref))</td> <td width="70%" class="table_cells"><b>insert_key_a</b>(ref, value_ref)</td> |
| </tr> <tr> |
| <td class="table_cells"> ref.insert(vt(key_ref,value_ref)) </td> |
| <td class="table_cells"> <strong>insert_at_a</strong>(ref, key_ref_, value_ref)</td> |
| </tr> |
| <tr> |
| <td class="table_cells"> ref.insert(vt(key_ref,value)) </td> |
| <td class="table_cells"> <strong>insert_at_a</strong>(ref, key_ref) </td> |
| </tr> |
| <td class="table_cells">ref[value] = value_ref</td> |
| <td class="table_cells"><b>assign_key_a</b>(ref, value_ref)</td> |
| </tr> |
| <td class="table_cells">ref.erase(ref,value)</td> |
| <td class="table_cells"><b>erase_a</b>(ref)</td> |
| </tr> |
| <td class="table_cells">ref.erase(ref,key_ref)</td> |
| <td class="table_cells"><b>erase_a</b>(ref, key_ref)</td> |
| </tr> |
| </table> |
| <table width="90%" border="0" align="center"> |
| <tr> |
| <td class="table_title" colspan="8"> Miscellanous actors </td> |
| </tr> |
| <tr> |
| <td width="30%" class="table_cells">swaps aref and bref</td> |
| <td width="70%" class="table_cells"><strong>swap_a</strong>(aref, bref)</td> |
| </tr> |
| </table> |
| <h3>Include Files</h3> |
| <p>The header files for the predefined actors are located in <tt>boost/spirit/actor</tt>. |
| The file <tt>actors.hpp</tt> contains all the includes for all the actors. You |
| may include just the specific header files that you need. The list below enumerates |
| the header files.</p> |
| <pre> <span class="preprocessor">#include</span> <span class="special"><</span>boost<span class="special">/</span>spirit<span class="special">/</span>actor<span class="special">/</span><span class="identifier">assign_actor</span><span class="special">.</span>hpp<span class="special">><br></span> <span class="preprocessor">#include</span> <span class="special"><</span>boost<span class="special">/</span>spirit<span class="special">/</span>actor<span class="special">/</span>assign_key_actor<span class="special">.</span>hpp<span class="special">></span><span class="special"></span><span class="special"></span> |
| <span class="preprocessor">#include</span> <span class="special"><</span>boost<span class="special">/</span>spirit<span class="special">/</span>actor<span class="special">/</span><span class="identifier">clear_actor</span><span class="special">.</span>hpp<span class="special">></span><span class="special"></span><span class="special"></span> |
| <span class="preprocessor">#include</span> <span class="special"><</span>boost<span class="special">/</span>spirit<span class="special">/</span>actor<span class="special">/</span><span class="identifier">decrement_actor</span><span class="special">.</span>hpp<span class="special">></span><span class="special"></span><span class="special"></span> |
| <span class="preprocessor">#include</span> <span class="special"><</span>boost<span class="special">/</span>spirit<span class="special">/</span>actor<span class="special">/</span><span class="identifier">erase_actor</span><span class="special">.</span>hpp<span class="special">></span><span class="special"></span> <br> <span class="preprocessor">#include</span> <span class="special"><</span>boost<span class="special">/</span>spirit<span class="special">/</span>actor<span class="special">/</span><span class="identifier">increment_actor</span><span class="special">.</span>hpp<span class="special">><br></span> <span class="preprocessor">#include</span> <span class="special"><</span>boost<span class="special">/</span>spirit<span class="special">/</span>actor<span class="special">/</span><span class="identifier">insert_key_actor</span><span class="special">.</span>hpp<span class="special">></span><span class="special"></span><span class="special"></span> |
| <span class="preprocessor">#include</span> <span class="special"><</span>boost<span class="special">/</span>spirit<span class="special">/</span>actor<span class="special">/</span>insert_at_actor.hpp<span class="special">></span> |
| <span class="preprocessor">#include</span> <span class="special"><</span>boost<span class="special">/</span>spirit<span class="special">/</span>actor<span class="special">/</span><span class="identifier">push_back_actor</span><span class="special">.</span>hpp<span class="special">></span><span class="special"></span><span class="special"></span> |
| <span class="preprocessor">#include</span> <span class="special"><</span>boost<span class="special">/</span>spirit<span class="special">/</span>actor<span class="special">/</span><span class="identifier">push_front_actor</span><span class="special">.</span>hpp<span class="special">></span><span class="special"></span><span class="special"></span> |
| <span class="preprocessor">#include</span> <span class="special"><</span>boost<span class="special">/</span>spirit<span class="special">/</span>actor<span class="special">/</span><span class="identifier">swap_actor</span><span class="special">.</span>hpp<span class="special">></span><span class="special"></span><span class="special"></span></pre> |
| <h3>Examples</h3> |
| <h4>Increment a value</h4> |
| <p> |
| Suppose that your input string is </p> |
| <code> |
| <pre> 1,2,-3,4,... |
| </pre> |
| </code><p> |
| and we want to count the number of ints. The actor <tt>increment_a</tt> applies <tt>++</tt> to its reference:</p> |
| <code> |
| <pre> <span class=keyword>int </span><span class=identifier>count </span><span class=special>= </span><span class=number>0</span><span class=special>; |
| </span><span class=identifier>rule</span><span class=special><> </span><span class=identifier>r </span><span class=special>= </span><span class=identifier>list_p</span><span class=special>.</span><span class=identifier>direct</span><span class=special>(</span><span class=identifier>int_p</span><span class=special>[</span><span class=identifier>increment_a</span><span class=special>(</span><span class=identifier>count</span><span class=special>)], </span><span class=identifier>ch_p</span><span class=special>(</span><span class=literal>','</span><span class=special>));</span></pre> |
| </code> |
| <h4>Append values to a vector (or other container)</h4> |
| <p> Here, you want to fill a <tt>vector<int></tt> with the numbers. The |
| actor <tt>push_back_a</tt> can be used to insert the integers at the back of |
| the vector:</p> |
| <code> |
| <pre> <span class=identifier>vector</span><span class=special><</span><span class=keyword>int</span><span class=special>> </span><span class=identifier>v</span><span class=special>; |
| </span><span class=identifier>rule</span><span class=special><> </span><span class=identifier>r </span><span class=special>= </span><span class=identifier>list_p</span><span class=special>.</span><span class=identifier>direct</span><span class=special>(</span><span class=identifier>int_p</span><span class=special>[</span><span class=identifier>push_back_a</span><span class=special>(</span><span class=identifier>v</span><span class=special>)], </span><span class=identifier>ch_p</span><span class=special>(</span><span class=literal>','</span><span class=special>));</span></pre> |
| </code> |
| <h4>insert key-value pairs into a map</h4><p> |
| Suppose that your input string is </p> |
| <code> |
| <pre> (1,2) (3,4) ... |
| </pre> |
| </code> |
| <p> and you want to parse the pair into a <tt>map<int,int></tt>. <tt>assign_a</tt> |
| can be used to store key and values in a temporary key variable, while <tt>insert_a</tt> |
| is used to insert it into the map:</p> |
| <pre> <code><span class=identifier>map</span><span class=special><</span><span class=keyword>int</span><span class=special>, </span><span class=keyword>int</span><span class="special">>::</span>value_type<span class=keyword> </span>k<span class=special>; |
| </span><span class=identifier>map</span><span class=special><</span><span class=keyword>int</span><span class=special>, </span><span class=keyword>int</span><span class=special>> </span><span class=identifier>m</span><span class=special>; |
| |
| </span><span class=identifier>rule</span><span class=special><> </span><span class=identifier>pair </span><span class=special>= </span><span class=identifier> |
| confix_p</span><span class=special>( |
| </span><span class=literal>'('</span><span class=special> |
| , </span><span class=identifier>int_p</span><span class=special>[</span><span class=identifier>assign_a</span><span class=special>(</span>k.first<span class=special>)] >> </span><span class=literal>','</span><span class=special> >> </span><span class=identifier>int_p</span><span class=special>[</span><span class=identifier>assign_a</span><span class=special>(</span>k.second<span class=special>)] |
| ,</span><span class=literal> ')' |
| </span><span class=special>)<br> [</span><span class=identifier>insert_at_a</span><span class=special>(</span><span class=identifier>m</span><span class=special>, </span><span class=identifier>k</span><span class=identifier></span><span class=special>)] |
| ;</span></code></pre> |
| <h2>Policy holder actors and policy actions</h2> |
| <p> The action takes place through a call to the <tt>()</tt> operator: single |
| argument <tt>()</tt> operator call for character parsers and two argument (first, |
| last) call for phrase parsers. Actors should implement at least one of the two |
| <tt>()</tt> operator.</p> |
| <p> |
| A lot of actors need to store reference to one or more objects. For |
| example, actions on container need to store a reference to the container.</p> |
| <p> Therefore, this kind of actor have been broken down into <strong>a)</strong> |
| an action policy that does the action (act member function), <strong>b)</strong> |
| policy holder actor that stores the references and feeds the act member function.</p> |
| <h3>Policy holder actors</h3> |
| <p> The available policy holders are enumerated below.</p> |
| <table width="90%" border="0" align="center"> |
| <tr> |
| <td class="table_title" colspan="24"> Policy holders </td> |
| </tr> |
| <tr> |
| <td class="table_cells">Name</td> |
| <td class="table_cells">Stored variables</td> |
| <td class="table_cells">Act signature</td> |
| </tr> |
| <td class="table_cells">ref_actor</td> |
| <td class="table_cells">1 reference</td> |
| <td class="table_cells"><tt>act(ref)</tt></td> |
| </tr> |
| <td class="table_cells">ref_value_actor</td> |
| <td class="table_cells">1 ref</td> |
| <td class="table_cells"> <tt>act(ref, value)</tt> or <tt>act(ref, first, last)</tt></td> |
| </tr> |
| <td class="table_cells">ref_const_ref_actor</td> |
| <td class="table_cells">1 ref and 1 const ref</td> |
| <td class="table_cells"><tt>act(ref, const_ref)</tt></td> |
| </tr> |
| <td class="table_cells">ref_const_ref_value_actor</td> |
| <td class="table_cells">1 ref</td> |
| <td class="table_cells"><tt>act(ref, value)</tt> or <tt>act(ref, first, last)</tt></td> |
| </tr> |
| <td class="table_cells">ref_const_ref_const_ref_actor</td> |
| <td class="table_cells">1 ref, 2 const ref</td> |
| <td class="table_cells"><tt>act(ref, const_ref1, const_ref2)</tt></td> |
| </tr> |
| </table> |
| <h3>Include Files</h3> |
| <p>The predefined policy header files are located in <tt>boost/spirit/actor</tt>:</p> |
| <pre> <span class="preprocessor">#include</span> <span class="special"><</span>boost<span class="special">/</span>spirit<span class="special">/</span>actor<span class="special">/</span>ref_actor<span class="special">.</span>hpp<span class="special">><br></span> <span class="preprocessor">#include</span> <span class="special"><</span>boost<span class="special">/</span>spirit<span class="special">/</span>actor<span class="special">/</span>ref_value_actor<span class="special">.</span>hpp<span class="special">></span><span class="special"></span><span class="special"></span> |
| <span class="preprocessor">#include</span> <span class="special"><</span>boost<span class="special">/</span>spirit<span class="special">/</span>actor<span class="special">/</span>ref_const_ref<span class="special">.</span>hpp<span class="special">></span><span class="special"></span> |
| <span class="preprocessor">#include</span> <span class="special"><</span>boost<span class="special">/</span>spirit<span class="special">/</span>actor<span class="special">/</span>ref_const_ref_value<span class="special">.</span>hpp<span class="special">></span><span class="special"></span> |
| <span class="preprocessor">#include</span> <span class="special"><</span>boost<span class="special">/</span>spirit<span class="special">/</span>actor<span class="special">/</span>ref_const_ref_value<span class="special">.</span>hpp<span class="special">></span><span class="special"></span> |
| <span class="preprocessor">#include</span> <span class="special"><</span>boost<span class="special">/</span>spirit<span class="special">/</span>actor<span class="special">/</span>ref_const_ref_const_ref<span class="special">.</span>hpp<span class="special">></span><span class="special"></span></pre> |
| <h3>Holder naming convention</h3> |
| <p> Policy holder have the following naming convention:</p> |
| <pre> <code><member>_ >> *<member> >> !value >> actor</code></pre> |
| <p> where <tt>member</tt> is the action policy member which can be of type:</p> |
| <ul> |
| <li>ref, a reference</li> |
| <li>const_ref, a const reference</li> |
| <li>value, by value</li> |
| <li>empty, no stored members</li> |
| </ul> |
| <p> and <tt>value</tt> states if the policy uses the parse result or not.</p> |
| <h3>Holder example: <tt>ref_actor</tt> class</h3> |
| <pre><code> <span class=comment>// this is the building block for action that |
| // take a reference and the parse result |
| |
| </span><span class=keyword>template</span><span class=special>< |
| </span><span class=keyword>typename </span><span class=identifier>T</span><span class=special>,</span><span class="comment"> // reference type</span><span class=identifier> |
| </span><span class=keyword>typename </span><span class=identifier>ActionT </span><span class=comment>// action policy |
| </span><span class=special>> |
| </span><span class=keyword>class </span><span class=identifier>ref_value_actor </span><span class=special>: </span><span class=keyword>public </span><span class=identifier>ActionT |
| </span><span class=special>{ |
| </span> <span class=keyword>public</span><span class=special>: |
| |
| </span><span class=keyword>explicit </span><span class=identifier>ref_value_actor</span><span class=special>(</span><span class=identifier>T</span><span class=special>& </span><span class=identifier>ref_</span><span class=special>) |
| : </span><span class=identifier>ref</span><span class=special>(</span><span class=identifier>ref_</span><span class=special>){} |
| |
| </span><span class=keyword>template</span><span class=special><</span><span class=keyword>typename </span><span class=identifier>T2</span><span class=special>> |
| </span><span class=keyword>void operator</span><span class=special>()(</span><span class=identifier>T2 </span><span class=keyword>const</span><span class=special>& </span><span class=identifier>val</span><span class=special>) </span><span class=keyword>const |
| </span><span class=special>{ |
| </span><span class=identifier>act</span><span class=special>(</span><span class=identifier>ref</span><span class=special>, </span><span class=identifier>val</span><span class=special>);</span><span class="comment"> // defined in ActionT</span><span class=identifier> |
| </span><span class=special>} |
| |
| </span><span class=keyword>template</span><span class=special><</span><span class=keyword>typename </span><span class=identifier>IteratorT</span><span class=special>> |
| </span><span class=keyword>void operator</span><span class=special>()( |
| </span><span class=identifier>IteratorT </span><span class=keyword>const</span><span class=special>& </span><span class=identifier>first</span><span class=special>, |
| </span><span class=identifier>IteratorT </span><span class=keyword>const</span><span class=special>& </span><span class=identifier>last</span><span class=special>) </span><span class=keyword>const |
| </span><span class=special>{ |
| </span><span class=identifier>act</span><span class=special>(</span><span class=identifier>ref</span><span class=special>,</span><span class=identifier>first</span><span class=special>,</span><span class=identifier>last</span><span class=special>);</span><span class="comment"> // defined in ActionT</span><span class=identifier> |
| </span><span class=special>} |
| |
| </span><span class=keyword>private</span><span class=special>: |
| |
| </span><span class=identifier> T</span><span class=special>& </span><span class=identifier>ref</span><span class=special>; |
| };</span></code></pre> |
| <h3>Actor example: <tt>assign_actor</tt></h3> |
| <code> |
| <pre> <span class=comment>// assign_action assigns the parse result to the reference |
| |
| </span><span class=keyword>struct </span><span class=identifier>assign_action |
| </span><span class=special>{ |
| </span><span class=keyword>template</span><span class=special>< |
| </span><span class=keyword>typename </span><span class=identifier>T</span><span class=special>, |
| </span><span class=keyword>typename </span><span class=identifier>ValueT |
| </span><span class=special>> |
| </span><span class=keyword>void </span><span class=identifier>act</span><span class=special>(</span><span class=identifier>T</span><span class=special>& </span><span class=identifier>ref</span><span class=special>, </span><span class=identifier>ValueT </span><span class=keyword>const</span><span class=special>& </span><span class=identifier>value</span><span class=special>) </span><span class=keyword>const |
| </span><span class=special>{ |
| </span><span class=identifier>ref</span><span class=special> = </span><span class=special></span><span class=identifier>value</span><span class=special>; |
| } |
| |
| </span><span class=keyword>template</span><span class=special>< |
| </span><span class=keyword>typename </span><span class=identifier>T</span><span class=special>, |
| </span><span class=keyword>typename </span><span class=identifier>IteratorT |
| </span><span class=special>> |
| </span><span class=keyword>void </span><span class=identifier>act</span><span class=special>( |
| </span><span class=identifier>T</span><span class=special>& </span><span class=identifier>ref</span><span class=special>, |
| </span><span class=identifier>IteratorT </span><span class=keyword>const</span><span class=special>& </span><span class=identifier>first</span><span class=special>, |
| </span><span class=identifier>IteratorT </span><span class=keyword>const</span><span class=special>& </span><span class=identifier>last</span><span class=special>) </span><span class=keyword>const |
| </span><span class=special>{ |
| </span><span class=keyword>typedef </span><span class=keyword>typename </span><span class=identifier>T</span><span class=special>::</span><span class=identifier>value_type </span><span class=identifier>value_type</span><span class=special>; |
| </span><span class=identifier>value_type </span><span class=identifier>vt</span><span class=special>(</span><span class=identifier>first</span><span class=special>,</span><span class=identifier> last</span><span class=special>); |
| </span><span class=identifier>ref</span><span class=special> = </span><span class=special></span><span class=identifier>vt</span><span class=special>; |
| } |
| };</span></pre> |
| </code> |
| <h3>Helper function example: <tt>assign_a</tt> function</h3> |
| <code> |
| <pre> |
| <span class=comment>// assign_a is a polymorphic helper function that generators an |
| // assign_actor based on ref_value_actor, assign_action and the |
| // type of its argument. |
| |
| </span><span class=keyword>template</span><span class=special><</span><span class=keyword>typename </span><span class=identifier>T</span><span class=special>> |
| </span><span class=keyword>inline </span><span class=identifier>ref_value_actor</span><span class=special><</span><span class=identifier>T</span><span class=special>, </span>assign<span class=identifier>_action</span><span class=special>></span><span class=identifier> |
| assign_a</span><span class=special>(</span><span class=identifier>T</span><span class=special>& </span><span class=identifier>ref</span><span class=special>) |
| { |
| </span><span class=keyword>return </span><span class=identifier>ref_value_actor</span><span class=special><</span><span class=identifier>T</span><span class=special>,</span><span class=identifier> assign_action</span><span class=special>>(</span><span class=identifier>ref</span><span class=special>); |
| }</span></pre> |
| </code> |
| <table border="0"> |
| <tr> |
| <td width="30"><a href="../index.html"><img src="theme/u_arr.gif" border="0"></a></td> |
| <td width="30"><a href="indepth_the_parser_context.html"><img src="theme/l_arr.gif" width="20" height="19" border="0"></a></td> |
| <td width="20"><a href="parametric_parsers.html"><img src="theme/r_arr.gif" width="20" height="19" border="0"></a></td> |
| </tr> |
| </table> |
| <br> |
| <hr size="1"> |
| <p class="copyright">Copyright © 2003 <font color="#666666">Jonathan de Halleux</font><font size="2"><font size="2"><font color="#666666"> |
| </font></font> </font><br> |
| Copyright © 2003 Joel de Guzman<br> |
| <br> |
| <font size="2">Use, modification and distribution is subject to the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) </font> </p> |
| </body> |
| </html> |