=proto
int duk_is_object_coercible(duk_context *ctx, int index);

=stack
[ ... val! ... ]

=summary
<p>Returns 1 if value at <code>index</code> is object coercible, as defined in
<a href="http://www.ecma-international.org/ecma-262/5.1/#sec-9.10">CheckObjectCoercible</a>,
otherwise returns 0.  If <code>index</code> is invalid, also returns 0.</p>

<p>All Ecmascript types are object coercible except <code>undefined</code> and
<code>null</code>.  The custom buffer and pointer types are currently not object
coercible.</p>

=example
if (duk_is_object_coercible(ctx, -3)) {
    /* ... */
}

=tags
stack
object

=fixme
Make buffer and pointer object coercible, and give them a prototype object?