C语言结构体指针成员强制类型转换

 #include <stdio.h>
 #include <stdlib.h>

 typedef struct ListElmt_
 {
     void *data;
     struct ListElmt_ *next;
 } ListElmt;

 int main() {

     ListElmt list;
     //char str = 'a';
     //list.data = &str;
     //*(list.data) = 'a';

     list.data = malloc();
     *( (char *) list.data) = 'a';

     printf("%c", *( (char *) list.data));

     return ;
 }