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<a name="Complex"></a>
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<p>
Next: <a href="Complex-Type-Example.html#Complex-Type-Example" accesskey="n" rel="next">Complex Type Example</a>, Previous: <a href="Type-Example.html#Type-Example" accesskey="p" rel="prev">Type Example</a>, Up: <a href="Types.html#Types" accesskey="u" rel="up">Types</a> [<a href="Index.html#Index" title="Index" rel="index">Index</a>]</p>
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<a name="Complex-Types"></a>
<h4 class="subsection">2.3.4 Complex Types</h4>
<p>‘<samp>libffi</samp>’ supports the complex types defined by the C99
standard (<code>_Complex float</code>, <code>_Complex double</code> and
<code>_Complex long double</code> with the built-in type descriptors
<code>ffi_type_complex_float</code>, <code>ffi_type_complex_double</code> and
<code>ffi_type_complex_longdouble</code>.
</p>
<p>Custom complex types like <code>_Complex int</code> can also be used.
An <code>ffi_type</code> object has to be defined to describe the
complex type to ‘<samp>libffi</samp>’.
</p>
<a name="index-ffi_005ftype-2"></a>
<dl>
<dt><a name="index-ffi_005ftype-3"></a>Data type: <strong>ffi_type</strong></dt>
<dd><dl compact="compact">
<dt><code>size_t size</code></dt>
<dd><p>This must be manually set to the size of the complex type.
</p>
</dd>
<dt><code>unsigned short alignment</code></dt>
<dd><p>This must be manually set to the alignment of the complex type.
</p>
</dd>
<dt><code>unsigned short type</code></dt>
<dd><p>For a complex type, this must be set to <code>FFI_TYPE_COMPLEX</code>.
</p>
</dd>
<dt><code>ffi_type **elements</code></dt>
<dd>
<p>This is a ‘<samp>NULL</samp>’-terminated array of pointers to
<code>ffi_type</code> objects. The first element is set to the
<code>ffi_type</code> of the complex’s base type. The second element
must be set to <code>NULL</code>.
</p></dd>
</dl>
</dd></dl>
<p>The section <a href="Complex-Type-Example.html#Complex-Type-Example">Complex Type Example</a> shows a way to determine
the <code>size</code> and <code>alignment</code> members in a platform
independent way.
</p>
<p>For platforms that have no complex support in <code>libffi</code> yet,
the functions <code>ffi_prep_cif</code> and <code>ffi_prep_args</code> abort
the program if they encounter a complex type.
</p>
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