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| </div> |
| <div class="section"> |
| <div class="titlepage"><div><div><h5 class="title"> |
| <a name="spirit.karma.reference.numeric.boolean"></a><a class="link" href="boolean.html" title="Boolean Generators (bool_)">Boolean Generators |
| (<code class="computeroutput"><span class="identifier">bool_</span></code>)</a> |
| </h5></div></div></div> |
| <a name="spirit.karma.reference.numeric.boolean.description"></a><h6> |
| <a name="id1081588"></a> |
| <a class="link" href="boolean.html#spirit.karma.reference.numeric.boolean.description">Description</a> |
| </h6> |
| <p> |
| As you might expect, the <code class="computeroutput"><span class="identifier">bool_generator</span></code> |
| can generate output from boolean values. The <code class="computeroutput"><span class="identifier">bool_generator</span></code> |
| generator can be used to generate output from ordinary primitive C/C++ |
| <code class="computeroutput"><span class="keyword">bool</span></code> values or user defined |
| boolean types if the type follows certain expression requirements (for |
| more information about the requirements, see <a class="link" href="boolean.html#spirit.karma.reference.numeric.boolean.additional_requirements">below</a>)). |
| The <code class="computeroutput"><span class="identifier">bool_generator</span></code> is |
| a template class. Template parameters fine tune its behavior. |
| </p> |
| <a name="spirit.karma.reference.numeric.boolean.header"></a><h6> |
| <a name="id1081642"></a> |
| <a class="link" href="boolean.html#spirit.karma.reference.numeric.boolean.header">Header</a> |
| </h6> |
| <pre class="programlisting"><span class="comment">// forwards to <boost/spirit/home/karma/numeric/bool.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">include</span><span class="special">/</span><span class="identifier">karma_bool</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> |
| </pre> |
| <p> |
| Also, see <a class="link" href="../../../structure/include.html" title="Include">Include Structure</a>. |
| </p> |
| <a name="spirit.karma.reference.numeric.boolean.namespace"></a><h6> |
| <a name="id1081716"></a> |
| <a class="link" href="boolean.html#spirit.karma.reference.numeric.boolean.namespace">Namespace</a> |
| </h6> |
| <div class="informaltable"><table class="table"> |
| <colgroup><col></colgroup> |
| <thead><tr><th> |
| <p> |
| Name |
| </p> |
| </th></tr></thead> |
| <tbody> |
| <tr><td> |
| <p> |
| <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">spirit</span><span class="special">::</span><span class="identifier">lit</span> <span class="comment">// alias: |
| boost::spirit::karma::lit</span></code> |
| </p> |
| </td></tr> |
| <tr><td> |
| <p> |
| <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">spirit</span><span class="special">::</span><span class="identifier">bool_</span> <span class="comment">// |
| alias: boost::spirit::karma::bool_</span></code> |
| </p> |
| </td></tr> |
| <tr><td> |
| <p> |
| <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">spirit</span><span class="special">::</span><span class="identifier">true_</span> <span class="comment">// |
| alias: boost::spirit::karma::true_</span></code> |
| </p> |
| </td></tr> |
| <tr><td> |
| <p> |
| <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">spirit</span><span class="special">::</span><span class="identifier">false_</span> <span class="comment">// |
| alias: boost::spirit::karma::false_</span></code> |
| </p> |
| </td></tr> |
| </tbody> |
| </table></div> |
| <div class="note"><table border="0" summary="Note"> |
| <tr> |
| <td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="../../../../images/note.png"></td> |
| <th align="left">Note</th> |
| </tr> |
| <tr><td align="left" valign="top"><p> |
| <code class="computeroutput"><span class="identifier">lit</span></code> is reused by the |
| <a class="link" href="../string.html" title="String">String Generators</a>, |
| the <a class="link" href="../char.html" title="Char">Character Generators</a>, |
| and the Numeric Generators. In general, a char generator is created |
| when you pass in a character, a string generator is created when you |
| pass in a string, and a numeric generator is created when you use a |
| numeric (boolean) literal. |
| </p></td></tr> |
| </table></div> |
| <a name="spirit.karma.reference.numeric.boolean.synopsis"></a><h6> |
| <a name="id1081934"></a> |
| <a class="link" href="boolean.html#spirit.karma.reference.numeric.boolean.synopsis">Synopsis</a> |
| </h6> |
| <pre class="programlisting"><span class="keyword">template</span> <span class="special"><</span> |
| <span class="keyword">typename</span> <span class="identifier">B</span> |
| <span class="special">,</span> <span class="keyword">unsigned</span> <span class="identifier">Policies</span><span class="special">></span> |
| <span class="keyword">struct</span> <span class="identifier">bool_generator</span><span class="special">;</span> |
| </pre> |
| <a name="spirit.karma.reference.numeric.boolean.template_parameters"></a><h6> |
| <a name="id1082004"></a> |
| <a class="link" href="boolean.html#spirit.karma.reference.numeric.boolean.template_parameters">Template |
| parameters</a> |
| </h6> |
| <div class="informaltable"><table class="table"> |
| <colgroup> |
| <col> |
| <col> |
| <col> |
| </colgroup> |
| <thead><tr> |
| <th> |
| <p> |
| Parameter |
| </p> |
| </th> |
| <th> |
| <p> |
| Description |
| </p> |
| </th> |
| <th> |
| <p> |
| Default |
| </p> |
| </th> |
| </tr></thead> |
| <tbody> |
| <tr> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">B</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| The boolean base type of the boolean generator. |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="keyword">bool</span></code> |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">Policies</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| The policies to use while converting the boolean. |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">bool_policies</span><span class="special"><</span><span class="identifier">B</span><span class="special">></span></code> |
| </p> |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| <a name="spirit.karma.reference.numeric.boolean.model_of"></a><h6> |
| <a name="id1082152"></a> |
| <a class="link" href="boolean.html#spirit.karma.reference.numeric.boolean.model_of">Model |
| of</a> |
| </h6> |
| <div class="blockquote"><blockquote class="blockquote"><p> |
| <a class="link" href="../generator_concepts/primitivegenerator.html" title="PrimitiveGenerator"><code class="computeroutput"><span class="identifier">PrimitiveGenerator</span></code></a> |
| </p></blockquote></div> |
| <div class="variablelist"> |
| <p class="title"><b>Notation</b></p> |
| <dl> |
| <dt><span class="term"><code class="computeroutput"><span class="identifier">b</span></code></span></dt> |
| <dd><p> |
| Boolean literal, or a <a class="link" href="../karma_basics.html#spirit.karma.reference.karma_basics.lazy_argument">Lazy |
| Argument</a> that evaluates to a boolean value of type <code class="computeroutput"><span class="identifier">B</span></code> |
| </p></dd> |
| <dt><span class="term"><code class="computeroutput"><span class="identifier">B</span></code></span></dt> |
| <dd><p> |
| Type of <code class="computeroutput"><span class="identifier">b</span></code>: any |
| type usable as a boolean, or in case of a <a class="link" href="../karma_basics.html#spirit.karma.reference.karma_basics.lazy_argument">Lazy |
| Argument</a>, its return value |
| </p></dd> |
| </dl> |
| </div> |
| <a name="spirit.karma.reference.numeric.boolean.expression_semantics"></a><h6> |
| <a name="id1082256"></a> |
| <a class="link" href="boolean.html#spirit.karma.reference.numeric.boolean.expression_semantics">Expression |
| Semantics</a> |
| </h6> |
| <p> |
| Semantics of an expression is defined only where it differs from, or |
| is not defined in <a class="link" href="../generator_concepts/primitivegenerator.html" title="PrimitiveGenerator"><code class="computeroutput"><span class="identifier">PrimitiveGenerator</span></code></a>. |
| </p> |
| <div class="informaltable"><table class="table"> |
| <colgroup> |
| <col> |
| <col> |
| </colgroup> |
| <thead><tr> |
| <th> |
| <p> |
| Expression |
| </p> |
| </th> |
| <th> |
| <p> |
| Semantics |
| </p> |
| </th> |
| </tr></thead> |
| <tbody> |
| <tr> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">lit</span><span class="special">(</span><span class="identifier">b</span><span class="special">)</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| Generate the boolean literal <code class="computeroutput"><span class="identifier">b</span></code> |
| using the default formatting (<code class="computeroutput"><span class="keyword">false</span></code> |
| is generated as <code class="computeroutput"><span class="string">"false"</span></code>, |
| and <code class="computeroutput"><span class="keyword">true</span></code> is generated |
| as <code class="computeroutput"><span class="string">"true"</span></code>). |
| This generator never fails (unless the underlying output stream |
| reports an error). |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">bool_</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| Generate the boolean value provided by a mandatory attribute |
| using the default formatting (<code class="computeroutput"><span class="keyword">false</span></code> |
| is generated as <code class="computeroutput"><span class="string">"false"</span></code>, |
| and <code class="computeroutput"><span class="keyword">true</span></code> is generated |
| as <code class="computeroutput"><span class="string">"true"</span></code>). |
| This generator never fails (unless the underlying output stream |
| reports an error). |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">bool_</span><span class="special">(</span><span class="identifier">b</span><span class="special">)</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| Generate the boolean value provided by the immediate literal |
| value the generator is initialized from using the default formatting |
| (<code class="computeroutput"><span class="keyword">false</span></code> is generated |
| as <code class="computeroutput"><span class="string">"false"</span></code>, |
| and <code class="computeroutput"><span class="keyword">true</span></code> is generated |
| as <code class="computeroutput"><span class="string">"true"</span></code>). |
| If this generator has an associated attribute it succeeds only |
| if the attribute is equal to the immediate literal (unless |
| the underlying output stream reports an error). Otherwise this |
| generator fails and does not generate any output. |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">true_</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| Generate <code class="computeroutput"><span class="string">"true"</span></code>. |
| If this generator has an associated attribute it succeeds only |
| if the attribute is <code class="computeroutput"><span class="keyword">true</span></code> |
| as well (unless the underlying output stream reports an error). |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">false_</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| Generate <code class="computeroutput"><span class="string">"false"</span></code>. |
| If this generator has an associated attribute it succeeds only |
| if the attribute is <code class="computeroutput"><span class="keyword">false</span></code> |
| as well (unless the underlying output stream reports an error). |
| </p> |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| <p> |
| All generators listed in the table above (except <code class="computeroutput"><span class="identifier">lit</span><span class="special">(</span><span class="identifier">num</span><span class="special">)</span></code>) are predefined specializations of the |
| <code class="computeroutput"><span class="identifier">bool_generator</span><span class="special"><</span><span class="identifier">B</span><span class="special">,</span> <span class="identifier">Policies</span><span class="special">></span></code> |
| basic boolean generator type described below. It is possible to directly |
| use this type to create boolean generators using a wide range of formatting |
| options. |
| </p> |
| <div class="informaltable"><table class="table"> |
| <colgroup> |
| <col> |
| <col> |
| </colgroup> |
| <thead><tr> |
| <th> |
| <p> |
| Expression |
| </p> |
| </th> |
| <th> |
| <p> |
| Semantics |
| </p> |
| </th> |
| </tr></thead> |
| <tbody> |
| <tr> |
| <td> |
| <p> |
| |
| </p> |
| <pre xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="table-programlisting"><span class="identifier">bool_generator</span><span class="special"><</span> |
| <span class="identifier">B</span><span class="special">,</span> <span class="identifier">Policies</span> |
| <span class="special">>()</span></pre> |
| <p> |
| </p> |
| </td> |
| <td> |
| <p> |
| Generate the boolean of type <code class="computeroutput"><span class="identifier">B</span></code> |
| provided by a mandatory attribute using the specified <code class="computeroutput"><span class="identifier">Policies</span></code> This generator never |
| fails (unless the underlying output stream reports an error). |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| |
| </p> |
| <pre xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="table-programlisting"><span class="identifier">bool_generator</span><span class="special"><</span> |
| <span class="identifier">B</span><span class="special">,</span> <span class="identifier">Policies</span> |
| <span class="special">>()(</span><span class="identifier">b</span><span class="special">)</span></pre> |
| <p> |
| </p> |
| </td> |
| <td> |
| <p> |
| Generate the boolean of type <code class="computeroutput"><span class="identifier">B</span></code> |
| provided by the immediate literal value the generator is initialized |
| from, using the specified <code class="computeroutput"><span class="identifier">Policies</span></code>. |
| If this generator has an associated attribute it succeeds only |
| if the attribute is equal to the immediate literal (unless |
| the underlying output stream reports an error). Otherwise this |
| generator fails and does not generate any output. |
| </p> |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| <div class="note"><table border="0" summary="Note"> |
| <tr> |
| <td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="../../../../images/note.png"></td> |
| <th align="left">Note</th> |
| </tr> |
| <tr><td align="left" valign="top"><p> |
| All boolean generators properly respect the <a class="link" href="../directive/upperlower.html" title="Directives Controlling Case Sensitivity (upper[], lower[])"><code class="computeroutput"><span class="identifier">upper</span></code></a> and <a class="link" href="../directive/upperlower.html" title="Directives Controlling Case Sensitivity (upper[], lower[])"><code class="computeroutput"><span class="identifier">lower</span></code></a> directives. |
| </p></td></tr> |
| </table></div> |
| <a name="spirit.karma.reference.numeric.boolean.additional_requirements"></a><h6> |
| <a name="id1083593"></a> |
| <a class="link" href="boolean.html#spirit.karma.reference.numeric.boolean.additional_requirements">Additional |
| Requirements</a> |
| </h6> |
| <p> |
| The following lists enumerate the requirements which must be met in order |
| to use a certain type <code class="computeroutput"><span class="identifier">B</span></code> |
| to instantiate and use a <code class="computeroutput"><span class="identifier">bool_generator</span><span class="special"><</span><span class="identifier">B</span><span class="special">,</span> <span class="identifier">Policies</span><span class="special">></span></code>. |
| </p> |
| <p> |
| The type <code class="computeroutput"><span class="identifier">B</span></code>: |
| </p> |
| <div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"> |
| must be (safely) convertible to <code class="computeroutput"><span class="keyword">bool</span></code> |
| </li></ul></div> |
| <a name="spirit.karma.reference.numeric.boolean.attributes"></a><h6> |
| <a name="id1083675"></a> |
| <a class="link" href="boolean.html#spirit.karma.reference.numeric.boolean.attributes">Attributes</a> |
| </h6> |
| <div class="informaltable"><table class="table"> |
| <colgroup> |
| <col> |
| <col> |
| </colgroup> |
| <thead><tr> |
| <th> |
| <p> |
| Expression |
| </p> |
| </th> |
| <th> |
| <p> |
| Attribute |
| </p> |
| </th> |
| </tr></thead> |
| <tbody> |
| <tr> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">bool_</span><span class="special">(</span><span class="identifier">b</span><span class="special">)</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">unused</span></code> |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">bool_</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="keyword">bool</span></code>, attribute |
| is mandatory (otherwise compilation will fail) |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">bool_</span><span class="special">(</span><span class="identifier">b</span><span class="special">)</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="keyword">bool</span></code>, attribute |
| is optional, if it is supplied, the generator compares the |
| attribute with <code class="computeroutput"><span class="identifier">b</span></code> |
| and succeeds only if both are equal, failing otherwise. |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| |
| </p> |
| <pre xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="table-programlisting"><span class="identifier">bool_generator</span><span class="special"><</span> |
| <span class="identifier">B</span><span class="special">,</span> <span class="identifier">Policies</span> |
| <span class="special">>()</span></pre> |
| <p> |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">B</span></code>, attribute |
| is mandatory (otherwise compilation will fail) |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| |
| </p> |
| <pre xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="table-programlisting"><span class="identifier">bool_generator</span><span class="special"><</span> |
| <span class="identifier">B</span><span class="special">,</span> <span class="identifier">Policies</span> |
| <span class="special">>()(</span><span class="identifier">b</span><span class="special">)</span></pre> |
| <p> |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">B</span></code>, attribute |
| is optional, if it is supplied, the generator compares the |
| attribute with <code class="computeroutput"><span class="identifier">b</span></code> |
| and succeeds only if both are equal, failing otherwise. |
| </p> |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| <div class="note"><table border="0" summary="Note"> |
| <tr> |
| <td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="../../../../images/note.png"></td> |
| <th align="left">Note</th> |
| </tr> |
| <tr><td align="left" valign="top"><p> |
| In addition to their usual attribute of type <code class="computeroutput"><span class="identifier">B</span></code> |
| all listed generators accept an instance of a <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">optional</span><span class="special"><</span><span class="identifier">B</span><span class="special">></span></code> as well. If the <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">optional</span><span class="special"><></span></code> is initialized (holds a value) |
| the generators behave as if their attribute was an instance of <code class="computeroutput"><span class="identifier">B</span></code> and emit the value stored in the |
| <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">optional</span><span class="special"><></span></code>. |
| Otherwise the generators will fail. |
| </p></td></tr> |
| </table></div> |
| <a name="spirit.karma.reference.numeric.boolean.boolean_formatting_policies"></a><h6> |
| <a name="id1084056"></a> |
| <a class="link" href="boolean.html#spirit.karma.reference.numeric.boolean.boolean_formatting_policies">Boolean |
| Formatting Policies</a> |
| </h6> |
| <p> |
| If special formatting of a boolean is needed, overload the policy class |
| <code class="computeroutput"><span class="identifier">bool_policies</span><span class="special"><</span><span class="identifier">B</span><span class="special">></span></code> |
| and use it as a template parameter to the <code class="computeroutput"><span class="identifier">bool_generator</span><span class="special"><></span></code> boolean generator. For instance: |
| </p> |
| <pre class="programlisting"><span class="keyword">struct</span> <span class="identifier">special_bool_policy</span> <span class="special">:</span> <span class="identifier">karma</span><span class="special">::</span><span class="identifier">bool_policies</span><span class="special"><></span> |
| <span class="special">{</span> |
| <span class="keyword">template</span> <span class="special"><</span><span class="keyword">typename</span> <span class="identifier">CharEncoding</span><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">Tag</span> |
| <span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">OutputIterator</span><span class="special">></span> |
| <span class="keyword">static</span> <span class="keyword">bool</span> <span class="identifier">generate_false</span><span class="special">(</span><span class="identifier">OutputIterator</span><span class="special">&</span> <span class="identifier">sink</span><span class="special">,</span> <span class="keyword">bool</span> <span class="identifier">b</span><span class="special">)</span> |
| <span class="special">{</span> |
| <span class="comment">// we want to spell the names of false as eurt (true backwards) |
| </span> <span class="keyword">return</span> <span class="identifier">string_inserter</span><span class="special"><</span><span class="identifier">CharEncoding</span><span class="special">,</span> <span class="identifier">Tag</span><span class="special">>::</span><span class="identifier">call</span><span class="special">(</span><span class="identifier">sink</span><span class="special">,</span> <span class="string">"eurt"</span><span class="special">);</span> |
| <span class="special">}</span> |
| <span class="special">};</span> |
| |
| <span class="keyword">typedef</span> <span class="identifier">karma</span><span class="special">::</span><span class="identifier">bool_generator</span><span class="special"><</span><span class="identifier">special_bool_policy</span><span class="special">></span> <span class="identifier">backwards_bool_type</span><span class="special">;</span> |
| <span class="identifier">backwards_bool_type</span> <span class="keyword">const</span> <span class="identifier">backwards_bool</span><span class="special">;</span> |
| |
| <span class="identifier">karma</span><span class="special">::</span><span class="identifier">generate</span><span class="special">(</span><span class="identifier">sink</span><span class="special">,</span> <span class="identifier">backwards_bool</span><span class="special">,</span> <span class="keyword">true</span><span class="special">);</span> <span class="comment">// will output: true |
| </span><span class="identifier">karma</span><span class="special">::</span><span class="identifier">generate</span><span class="special">(</span><span class="identifier">sink</span><span class="special">,</span> <span class="identifier">backwards_bool</span><span class="special">(</span><span class="keyword">false</span><span class="special">));</span> <span class="comment">// will output: uert |
| </span></pre> |
| <p> |
| The template parameter <code class="computeroutput"><span class="identifier">B</span></code> |
| should be the type to be formatted using the overloaded policy type. |
| At the same time <code class="computeroutput"><span class="identifier">B</span></code> will |
| be used as the attribute type of the created real number generator. The |
| default for <code class="computeroutput"><span class="identifier">B</span></code> is <code class="computeroutput"><span class="keyword">bool</span></code>. |
| </p> |
| <a name="spirit.karma.reference.numeric.boolean.boolean_formatting_policy_expression_semantics"></a><h6> |
| <a name="id1084479"></a> |
| <a class="link" href="boolean.html#spirit.karma.reference.numeric.boolean.boolean_formatting_policy_expression_semantics">Boolean |
| Formatting Policy Expression Semantics</a> |
| </h6> |
| <p> |
| A boolean formatting policy should expose the following: |
| </p> |
| <div class="informaltable"><table class="table"> |
| <colgroup> |
| <col> |
| <col> |
| </colgroup> |
| <thead><tr> |
| <th> |
| <p> |
| Expression |
| </p> |
| </th> |
| <th> |
| <p> |
| Description |
| </p> |
| </th> |
| </tr></thead> |
| <tbody> |
| <tr> |
| <td> |
| <p> |
| |
| </p> |
| <pre xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="table-programlisting"><span class="keyword">template</span> <span class="special"><</span><span class="keyword">typename</span> <span class="identifier">Inserter</span> |
| <span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">OutputIterator</span> |
| <span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">Policies</span><span class="special">></span> |
| <span class="keyword">bool</span> <span class="identifier">call</span> <span class="special">(</span><span class="identifier">OutputIterator</span><span class="special">&</span> <span class="identifier">sink</span><span class="special">,</span> <span class="identifier">Num</span> <span class="identifier">n</span> |
| <span class="special">,</span> <span class="identifier">Policies</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">p</span><span class="special">);</span> |
| </pre> |
| <p> |
| </p> |
| </td> |
| <td> |
| <p> |
| This is the main function used to generate the output for a |
| boolean. It is called by the boolean generator in order to |
| perform the conversion. In theory all of the work can be implemented |
| here, but the easiest way is to use existing functionality |
| provided by the type specified by the template parameter <code class="computeroutput"><span class="identifier">Inserter</span></code>. The default implementation |
| of this functions is: |
| </p> |
| <pre xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="table-programlisting"><span class="keyword">template</span> <span class="special"><</span><span class="keyword">typename</span> <span class="identifier">Inserter</span><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">OutputIterator</span> |
| <span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">Policies</span><span class="special">></span> |
| <span class="keyword">static</span> <span class="keyword">bool</span> |
| <span class="identifier">call</span> <span class="special">(</span><span class="identifier">OutputIterator</span><span class="special">&</span> <span class="identifier">sink</span><span class="special">,</span> <span class="identifier">B</span> <span class="identifier">b</span><span class="special">,</span> <span class="identifier">Policies</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">p</span><span class="special">)</span> |
| <span class="special">{</span> |
| <span class="keyword">return</span> <span class="identifier">Inserter</span><span class="special">::</span><span class="identifier">call_n</span><span class="special">(</span><span class="identifier">sink</span><span class="special">,</span> <span class="identifier">b</span><span class="special">,</span> <span class="identifier">p</span><span class="special">);</span> |
| <span class="special">}</span> |
| </pre> |
| <p> |
| <code class="computeroutput"><span class="identifier">sink</span></code> is the |
| output iterator to use for generation |
| </p> |
| <p> |
| <code class="computeroutput"><span class="identifier">b</span></code> is the boolean |
| to convert |
| </p> |
| <p> |
| <code class="computeroutput"><span class="identifier">p</span></code> is the instance |
| of the policy type used to instantiate this real number generator. |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| |
| </p> |
| <pre xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="table-programlisting"><span class="keyword">template</span> <span class="special"><</span><span class="keyword">typename</span> <span class="identifier">CharEncoding</span><span class="special">,</span> |
| <span class="keyword">typename</span> <span class="identifier">Tag</span><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">OutputIterator</span><span class="special">></span> |
| <span class="keyword">bool</span> <span class="identifier">generate_false</span><span class="special">(</span> |
| <span class="identifier">OutputIterator</span><span class="special">&</span> <span class="identifier">sink</span><span class="special">,</span> <span class="identifier">B</span> <span class="identifier">b</span><span class="special">);</span> |
| </pre> |
| <p> |
| </p> |
| </td> |
| <td> |
| <p> |
| This function is called to generate the boolean if it is <code class="computeroutput"><span class="keyword">false</span></code>. |
| </p> |
| <p> |
| <code class="computeroutput"><span class="identifier">sink</span></code> is the |
| output iterator to use for generation |
| </p> |
| <p> |
| <code class="computeroutput"><span class="identifier">b</span></code> is the boolean |
| to convert (the value is <code class="computeroutput"><span class="keyword">false</span></code>). |
| </p> |
| <p> |
| The template parameters <code class="computeroutput"><span class="identifier">CharEncoding</span></code> |
| and <code class="computeroutput"><span class="identifier">Tag</span></code> are |
| either of the type <code class="computeroutput"><span class="identifier">unused_type</span></code> |
| or describe the character class and conversion to be applied |
| to any output possibly influenced by either the <code class="computeroutput"><span class="identifier">lower</span><span class="special">[]</span></code> |
| or <code class="computeroutput"><span class="identifier">upper</span><span class="special">[]</span></code> |
| directives. |
| </p> |
| <p> |
| The return value defines the outcome of the whole generator. |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| |
| </p> |
| <pre xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="table-programlisting"><span class="keyword">template</span> <span class="special"><</span><span class="keyword">typename</span> <span class="identifier">CharEncoding</span><span class="special">,</span> |
| <span class="keyword">typename</span> <span class="identifier">Tag</span><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">OutputIterator</span><span class="special">></span> |
| <span class="keyword">bool</span> <span class="identifier">generate_true</span><span class="special">(</span> |
| <span class="identifier">OutputIterator</span><span class="special">&</span> <span class="identifier">sink</span><span class="special">,</span> <span class="identifier">B</span> <span class="identifier">b</span><span class="special">);</span> |
| </pre> |
| <p> |
| </p> |
| </td> |
| <td> |
| <p> |
| This function is called to generate the boolean if it is <code class="computeroutput"><span class="keyword">true</span></code>. |
| </p> |
| <p> |
| <code class="computeroutput"><span class="identifier">sink</span></code> is the |
| output iterator to use for generation |
| </p> |
| <p> |
| <code class="computeroutput"><span class="identifier">b</span></code> is the boolean |
| to convert (the value is <code class="computeroutput"><span class="keyword">true</span></code>). |
| </p> |
| <p> |
| The template parameters <code class="computeroutput"><span class="identifier">CharEncoding</span></code> |
| and <code class="computeroutput"><span class="identifier">Tag</span></code> are |
| either of the type <code class="computeroutput"><span class="identifier">unused_type</span></code> |
| or describe the character class and conversion to be applied |
| to any output possibly influenced by either the <code class="computeroutput"><span class="identifier">lower</span><span class="special">[]</span></code> |
| or <code class="computeroutput"><span class="identifier">upper</span><span class="special">[]</span></code> |
| directives. |
| </p> |
| <p> |
| The return value defines the outcome of the whole generator. |
| </p> |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| <a name="spirit.karma.reference.numeric.boolean.complexity"></a><h6> |
| <a name="id1085283"></a> |
| <a class="link" href="boolean.html#spirit.karma.reference.numeric.boolean.complexity">Complexity</a> |
| </h6> |
| <div class="blockquote"><blockquote class="blockquote"><p> |
| O(N), where <code class="computeroutput"><span class="identifier">N</span></code> is the |
| number of characters needed to represent the generated boolean. |
| </p></blockquote></div> |
| <a name="spirit.karma.reference.numeric.boolean.example"></a><h6> |
| <a name="id1085310"></a> |
| <a class="link" href="boolean.html#spirit.karma.reference.numeric.boolean.example">Example</a> |
| </h6> |
| <div class="note"><table border="0" summary="Note"> |
| <tr> |
| <td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="../../../../images/note.png"></td> |
| <th align="left">Note</th> |
| </tr> |
| <tr><td align="left" valign="top"><p> |
| The test harness for the example(s) below is presented in the <a class="link" href="../karma_basics.html#spirit.karma.reference.karma_basics.examples">Basics Examples</a> |
| section. |
| </p></td></tr> |
| </table></div> |
| <p> |
| Some includes: |
| </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">karma</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">include</span><span class="special">/</span><span class="identifier">phoenix_core</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">include</span><span class="special">/</span><span class="identifier">phoenix_operator</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">fusion</span><span class="special">/</span><span class="identifier">include</span><span class="special">/</span><span class="identifier">std_pair</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">iostream</span><span class="special">></span> |
| <span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">string</span><span class="special">></span> |
| </pre> |
| <p> |
| </p> |
| <p> |
| Some using declarations: |
| </p> |
| <p> |
| |
| </p> |
| <pre class="programlisting"><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">karma</span><span class="special">::</span><span class="identifier">bool_</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">karma</span><span class="special">::</span><span class="identifier">lit</span><span class="special">;</span> |
| </pre> |
| <p> |
| </p> |
| <p> |
| Basic usage of an <code class="computeroutput"><span class="identifier">bool_</span></code> |
| generator: |
| </p> |
| <p> |
| |
| </p> |
| <pre class="programlisting"><span class="identifier">test_generator</span><span class="special">(</span><span class="string">"true"</span><span class="special">,</span> <span class="identifier">lit</span><span class="special">(</span><span class="keyword">true</span><span class="special">));</span> |
| <span class="identifier">test_generator</span><span class="special">(</span><span class="string">"false"</span><span class="special">,</span> <span class="identifier">bool_</span><span class="special">(</span><span class="keyword">false</span><span class="special">));</span> |
| <span class="identifier">test_generator_attr</span><span class="special">(</span><span class="string">"true"</span><span class="special">,</span> <span class="identifier">bool_</span><span class="special">(</span><span class="keyword">true</span><span class="special">),</span> <span class="keyword">true</span><span class="special">);</span> |
| <span class="identifier">test_generator_attr</span><span class="special">(</span><span class="string">""</span><span class="special">,</span> <span class="identifier">bool_</span><span class="special">(</span><span class="keyword">true</span><span class="special">),</span> <span class="keyword">false</span><span class="special">);</span> <span class="comment">// fails (as true != false)! |
| </span><span class="identifier">test_generator_attr</span><span class="special">(</span><span class="string">"false"</span><span class="special">,</span> <span class="identifier">bool_</span><span class="special">,</span> <span class="keyword">false</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> |
| </tr></table> |
| <hr> |
| <div class="spirit-nav"> |
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