Re: pointer_to_function?

mdh wrote:
Could someone please help me understand p 119 of K&R?

This is a version of qsort that, depending on a command line optional
argument ( -n) sorts lines numerically vs lexicographically.

I think the relevant lines ( well, the ones I am having a problem
with) are as follows.


# include.....
etc
void qsort(void *lineptr[], int left, int right, int (*comp)(void *,
void *)); /** declaration**/

main......{
.....
if(qsort((void**) lineptr, 0, nlines-1, (int (*)(void*, void*))
(numeric ? numcmp:strcmp));
........
}

int (*)(void*, void*))(numeric ? numcmp:strcmp)

Is casting the result of (numeric ? numcmp:strcmp) to the required
function pointer type. I assume numcmp uses int* and strcmp uses const
char* for their parameters, hence the need for a cast.


--
Ian Collins.
.

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