rbage collection, too.
</p>
<p>
<b>Callbacks due to implicit conversions are permanent!</b> There is no
way to guess their lifetime, since the C&nbsp;side might store the
function pointer for later use (typical for GUI toolkits). The associated
resources cannot be reclaimed until termination:
</p>
<pre class="code">
ffi.cdef[[
typedef int (__stdcall *WNDENUMPROC)(void *hwnd, intptr_t l);
int EnumWindows(WNDENUMPROC func, intptr_t l);
]]

-- Implicit conversion to a callback via function pointer argument.
lo