Assign values to a dereferenced void pointer

Question

I'm doing a class in c++ that supports any kind of variable to help me in a future project. The thing is, when I try to assign a value to a void* variable, I get the error: void* is not a pointer-to-object type. Here is the code:

int main (void) {
    void* a;
    int x;
    a = malloc(sizeof(int));
    x = 120;
    ((int)(*a)) = x;
    printf("%d",((int)*a));
    free(a);
    system("pause");
    return 0;
}

I see it like I am trying to assign the value of x in the memory block reserved for a. I want that the value stored in x be stored in the memory block of a. Can any1 help me?

Answer 1

You probably want to do:

void* a;
int x;
a = malloc(sizeof(int));
x = 120;
*(int*)a = x;
printf("%d", * (int*)a);
free(a);

Answer 2

You're making it too complicated. Just cast a to be an int *, or better yet declare a as int * to start with.

int x = 120;
int * a ;
// now just cast the result from malloc as int*
if((a = (int *)malloc(sizeof(int))) == NULL){ //ALWAYS check
   exit(-1);
}
*a = x;

There are slicker ways to do similar things in C++, but you appear to be primarily caught up in pointer syntax.