User-defined comparison function that must be declared with __cdecl - C-style
calling convention. This function takes two arguments - elem1 and
elem2. These arguments are the pointers to the array elements. fcmp
function must compare these elements and return an integer value:
*elem1 < *elem2
- fcmp returns value < 0
*elem1 == *elem2
- fcmp returns value == 0
*elem1 > *elem2
- fcmp returns value > 0
Return value
None.
Remarks
See the C/C++ run-time library reference for more information.
If you need to pass user-defined data to the compare function, you should
use the qsortex function instead.
The sort implemented by the qsort and qsortex functions is not stable.
In other words, the order for the elements that are equal according to
the compare function is not defined. The order can change when the array
is sorted repeatedly.