+/* It's undefined behaviour in C99 to convert from a function pointer to
+ * a data-object pointer, e.g. void pointer. gcc's -pedantic warns of
+ * this and can stop compilation. POSIX requires the operation however,
+ * e.g. for dlsym(3), and so we know it's safe on POSIX platforms, e.g.
+ * the pointers are of the same size. Thus use a union to subvert gcc's
+ * check. The function-pointer equivalent of a void pointer is any
+ * function-pointer type as all function pointers are defined to be
+ * convertible from one another; use the simplest available. */
+typedef union {
+ void *v;
+ void (*f)(void);
+} generic_pointer;
+