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<h4 class="subsection">A.5.4 Structure Field Offset Measurement</h4>

<p>You can use <code>offsetof</code> to measure the location within a structure
type of a particular structure member.

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<div class="defun">
&mdash; Macro: size_t <b>offsetof</b> (<var>type, member</var>)<var><a name="index-offsetof-3812"></a></var><br>
<blockquote><p>This expands to a integer constant expression that is the offset of the
structure member named <var>member</var> in the structure type <var>type</var>. 
For example, <code>offsetof (struct s, elem)</code> is the offset, in bytes,
of the member <code>elem</code> in a <code>struct s</code>.

        <p>This macro won't work if <var>member</var> is a bit field; you get an error
from the C compiler in that case. 
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