void * pointers to type
jsval and vice versa.
#define PRIVATE_TO_JSVAL(p) /* ... */ #define JSVAL_TO_PRIVATE(v) /* ... */
PRIVATE_TO_JSVAL(), an application can store a private data pointer,
p, as a
jsval. This can be useful with reserved slots.
The private data pointer can point to application-defined memory of any type, but the pointer must be two-byte-aligned (that is,
(int) p must be even).