我一直在查看不同的qsort实现,并且在这里找到了源代码(https://code.woboq.org/userspace/glibc/stdlib/qsort.c.html)中有一行我不明白的内容。它看起来像是一个函数指针声明。希望得到任何帮助。为了回答这个问题,我已经包含了尽可能多的代码(并标注了该行),如果还有需要,请告诉我,谢谢。
typedef struct
{
char *lo;
char *hi;
} stack_node;
void _quicksort (void *const pbase, size_t total_elems, size_t size, cmp_t cmp, void *arg)
{
char *base_ptr = (char *) pbase;
const size_t max_thresh = 4 * size;
if (total_elems == 0)
return;
if (total_elems > 4)
{
char *lo = base_ptr;
char *hi = &lo[size * (total_elems - 1)];
stack_node stack[(8 * sizeof(size_t))];
stack_node *top = stack;
/* Line below is a function pointer declaration? Initializes struct? */
((void) ((top->lo = (((void*)0))), (top->hi = (((void*)0))), ++top));
while ((stack < top))
{
char *left_ptr;
char *right_ptr;
char *mid = lo + size * ((hi - lo) / size >> 1);
... code goes on
PUSH (NULL, NULL);
。你从哪里获取了这个版本,为什么要以这种形式查看它? - AnT stands with Russia