View Compilation Error

0_0_38372846_25419.cpp: In function 'int main()':
0_0_38372846_25419.cpp:11:27: error: cannot convert 'std::basic_string<char>::iterator {aka __gnu_cxx::__normal_iterator<char*, std::basic_string<char> >}' to 'void*' for argument '1' to 'void qsort(void*, size_t, size_t, int (*)(const void*, const void*))'
   qsort(s.begin(), s.end());
                           ^