[2]</tt>.</li>

<li>Otherwise use either <tt>tostring()</tt> on 64&nbsp;bit integers
or complex numbers or combine multiple fields of a cdata aggregate to
a Lua string (e.g. with
<a href="ext_ffi_api.html#ffi_string"><tt>ffi.string()</tt></a>). Then
use the resulting Lua string as a key when indexing tables.</li>

<li>Create your own specialized hash table implementation using the
C&nbsp;types provided by the FFI library, just like you would in
C&nbsp;code. Ultimately this may give much better performance t