Function element_compare

src/backend/utils/adt/array_selfuncs.c:1165–1176

* Comparison function for elements. * * We use the element type's default btree opclass, and its default collation * if the type is collation-sensitive. * * XXX consider using SortSupport infrastructure */

 * XXX consider using SortSupport infrastructure
 */
static int
element_compare(const void *key1, const void *key2, void *arg)
{
	Datum		d1 = *((const Datum *) key1);
	Datum		d2 = *((const Datum *) key2);
	TypeCacheEntry *typentry = (TypeCacheEntry *) arg;
	FmgrInfo   *cmpfunc = &typentry->cmp_proc_finfo;
	Datum		c;

	c = FunctionCall2Coll(cmpfunc, typentry->typcollation, d1, d2);
	return DatumGetInt32(c);
}

/*
 * Comparison function for sorting floats into descending order.