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<title>Complex (libffi: the portable foreign function interface library)</title>

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<div class="subsection-level-extent" id="Complex">
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Next: <a href="Complex-Type-Example.html" accesskey="n" rel="next">Complex Type Example</a>, Previous: <a href="Type-Example.html" accesskey="p" rel="prev">Type Example</a>, Up: <a href="Types.html" accesskey="u" rel="up">Types</a> &nbsp; [<a href="Index.html" title="Index" rel="index">Index</a>]</p>
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<h4 class="subsection" id="Complex-Types"><span>2.3.6 Complex Types<a class="copiable-link" href="#Complex-Types"> &para;</a></span></h4>

<p><code class="code">libffi</code> supports the complex types defined by the C99
standard (<code class="code">_Complex float</code>, <code class="code">_Complex double</code> and
<code class="code">_Complex long double</code> with the built-in type descriptors
<code class="code">ffi_type_complex_float</code>, <code class="code">ffi_type_complex_double</code> and
<code class="code">ffi_type_complex_longdouble</code>.
</p>
<p>Custom complex types like <code class="code">_Complex int</code> can also be used.
An <code class="code">ffi_type</code> object has to be defined to describe the
complex type to <code class="code">libffi</code>.
</p>
<a class="index-entry-id" id="index-ffi_005ftype-2"></a>
<dl class="first-deftp">
<dt class="deftp" id="index-ffi_005ftype-3"><span class="category-def">Data type: </span><span><strong class="def-name">ffi_type</strong><a class="copiable-link" href="#index-ffi_005ftype-3"> &para;</a></span></dt>
<dd><dl class="table">
<dt><code class="code">size_t size</code></dt>
<dd><p>This must be manually set to the size of the complex type.
</p>
</dd>
<dt><code class="code">unsigned short alignment</code></dt>
<dd><p>This must be manually set to the alignment of the complex type.
</p>
</dd>
<dt><code class="code">unsigned short type</code></dt>
<dd><p>For a complex type, this must be set to <code class="code">FFI_TYPE_COMPLEX</code>.
</p>
</dd>
<dt><code class="code">ffi_type **elements</code></dt>
<dd>
<p>This is a &lsquo;<samp class="samp">NULL</samp>&rsquo;-terminated array of pointers to
<code class="code">ffi_type</code> objects.  The first element is set to the
<code class="code">ffi_type</code> of the complex&rsquo;s base type.  The second element
must be set to <code class="code">NULL</code>.
</p></dd>
</dl>
</dd></dl>

<p>The section <a class="ref" href="Complex-Type-Example.html">Complex Type Example</a> shows a way to determine
the <code class="code">size</code> and <code class="code">alignment</code> members in a platform
independent way.
</p>
<p>For platforms that have no complex support in <code class="code">libffi</code> yet,
the functions <code class="code">ffi_prep_cif</code> and <code class="code">ffi_prep_args</code> abort
the program if they encounter a complex type.
</p>
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