是否可以在指向结构的第一个成员的指针上调用free（并且结构是与malloc相关的结构）？我原则上知道指针指向正确的东西......
struct s {int x;};
//in main
struct s* test;
test = (struct s*) malloc(sizeof(*test));
int* test2;
test2 = &(test->x);
free(test2); //is this okay??
此外，如果答案会改变 int x 被结构替换？
更新：为什么我要编写这样的代码？
struct s {int x;};
struct sx1 {struct s test; int y;}; //extending struct s
struct sx2 {struct s test; int z;}; //another
// ** some functions to keep track of the number of references to each variable of type struct s
int release(struct s* ptr){
//if the number of references to *ptr is 0 call free on ptr
}
int main(){
struct sx1* test1;
struct sx2* test2;
test1 = (sx1*) malloc(sizeof(*sx1));
test2 = (sx2*) malloc(sizeof(*sx2));
//code that changes the number of references to test1 and test2, calling functions defined in **
release(test1);
release(test2);
}