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<div class="titlepage"><div><div><h5 class="title">
<a name="spirit.karma.reference.generator_concepts.narygenerator"></a><a class="link" href="narygenerator.html" title="NaryGenerator">NaryGenerator</a>
</h5></div></div></div>
<a name="spirit.karma.reference.generator_concepts.narygenerator.description"></a><h6>
<a name="id1031878"></a>
<a class="link" href="narygenerator.html#spirit.karma.reference.generator_concepts.narygenerator.description">Description</a>
</h6>
<p>
<span class="emphasis"><em>NaryGenerator</em></span> is a composite generator that has
one or more subjects. The NaryGenerator allows its subjects to be treated
in the same way as a single instance of a <a class="link" href="generator.html" title="Generator"><code class="computeroutput"><span class="identifier">Generator</span></code></a> following the Composite
Design Pattern.
</p>
<a name="spirit.karma.reference.generator_concepts.narygenerator.refinement_of"></a><h6>
<a name="id1031909"></a>
<a class="link" href="narygenerator.html#spirit.karma.reference.generator_concepts.narygenerator.refinement_of">Refinement
of</a>
</h6>
<div class="blockquote"><blockquote class="blockquote"><p>
<a class="link" href="generator.html" title="Generator"><code class="computeroutput"><span class="identifier">Generator</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">g</span></code></span></dt>
<dd><p>
A NaryGenerator.
</p></dd>
<dt><span class="term"><code class="computeroutput"><span class="identifier">G</span></code></span></dt>
<dd><p>
A NaryGenerator type.
</p></dd>
</dl>
</div>
<a name="spirit.karma.reference.generator_concepts.narygenerator.valid_expressions"></a><h6>
<a name="id1031986"></a>
<a class="link" href="narygenerator.html#spirit.karma.reference.generator_concepts.narygenerator.valid_expressions">Valid
Expressions</a>
</h6>
<p>
In addition to the requirements defined in <a class="link" href="generator.html" title="Generator"><code class="computeroutput"><span class="identifier">Generator</span></code></a>, for any NaryGenerator
the following must be met:
</p>
<div class="informaltable"><table class="table">
<colgroup>
<col>
<col>
<col>
</colgroup>
<thead><tr>
<th>
<p>
Expression
</p>
</th>
<th>
<p>
Semantics
</p>
</th>
<th>
<p>
Return type
</p>
</th>
</tr></thead>
<tbody><tr>
<td>
<p>
<code class="computeroutput"><span class="identifier">g</span><span class="special">.</span><span class="identifier">elements</span></code>
</p>
</td>
<td>
<p>
The tuple of elements.
</p>
</td>
<td>
<p>
A <a href="../../../../../../../../libs/fusion/doc/html/index.html" target="_top">Boost.Fusion</a>
Sequence of <a class="link" href="generator.html" title="Generator"><code class="computeroutput"><span class="identifier">Generator</span></code></a> types.
</p>
</td>
</tr></tbody>
</table></div>
<a name="spirit.karma.reference.generator_concepts.narygenerator.type_expressions"></a><h6>
<a name="id1032110"></a>
<a class="link" href="narygenerator.html#spirit.karma.reference.generator_concepts.narygenerator.type_expressions">Type
Expressions</a>
</h6>
<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>
<code class="computeroutput"><span class="identifier">g</span><span class="special">.</span><span class="identifier">elements_type</span></code>
</p>
</td>
<td>
<p>
Elements tuple type.
</p>
</td>
</tr>
<tr>
<td>
<p>
<code class="computeroutput"><span class="identifier">traits</span><span class="special">::</span><span class="identifier">is_nary_generator</span><span class="special"><</span><span class="identifier">G</span><span class="special">>::</span><span class="identifier">type</span></code>
</p>
</td>
<td>
<p>
Metafunction that evaluates to <code class="computeroutput"><span class="identifier">mpl</span><span class="special">::</span><span class="identifier">true_</span></code>
if a certain type, <code class="computeroutput"><span class="identifier">G</span></code>
is a NaryGenerator, <code class="computeroutput"><span class="identifier">mpl</span><span class="special">::</span><span class="identifier">false_</span></code>
otherwise (See <a href="../../../../../../../../libs/mpl/doc/refmanual/integral-constant.html" target="_top">MPL
Boolean Constant</a>).
</p>
</td>
</tr>
</tbody>
</table></div>
<a name="spirit.karma.reference.generator_concepts.narygenerator.invariants"></a><h6>
<a name="id1032279"></a>
<a class="link" href="narygenerator.html#spirit.karma.reference.generator_concepts.narygenerator.invariants">Invariants</a>
</h6>
<p>
For each element, <code class="computeroutput"><span class="identifier">E</span></code>,
in any NaryGenerator, <code class="computeroutput"><span class="identifier">G</span></code>,
the following invariant always holds:
</p>
<div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem">
<code class="computeroutput"><span class="identifier">traits</span><span class="special">::</span><span class="identifier">is_generator</span><span class="special"><</span><span class="identifier">E</span><span class="special">>::</span><span class="identifier">type</span></code> evaluates to <code class="computeroutput"><span class="identifier">mpl</span><span class="special">::</span><span class="identifier">true_</span></code>
</li></ul></div>
<a name="spirit.karma.reference.generator_concepts.narygenerator.models"></a><h6>
<a name="id1032368"></a>
<a class="link" href="narygenerator.html#spirit.karma.reference.generator_concepts.narygenerator.models">Models</a>
</h6>
<p>
The following generators conform to this model:
</p>
<div class="itemizedlist"><ul class="itemizedlist" type="disc">
<li class="listitem">
<a class="link" href="../operator/sequence.html" title="Sequences (a << b)">Sequence
(<code class="computeroutput"><span class="special"><<</span></code>)</a>,
</li>
<li class="listitem">
<a class="link" href="../operator/alternative.html" title="Alternative (a | b)">Alternative
(<code class="computeroutput"><span class="special">|</span></code>)</a>.
</li>
</ul></div>
<p>
<span class="bold"><strong>FIXME</strong></span> Add more links to models of NaryGenerator
concept
</p>
</div>
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<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>
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