Question

(I want to deal with “void” I am avoid “template class” because it is too much trouble)

ok establish some ground

int aa=3;
int bb=4;
int cc=0;

int *a, *b, *c;

a = &aa;
b = &bb;
c = &cc;

*c = *a +*b; //yields 7

but I want to do the following:

void *va;
void *vb;
void *vc;

va = a;
vb = b;

*c = (int)(*va + *vb);  // <-- 3 errors see below

but I get errors:

 error C2100: illegal indirection
 error C2100: illegal indirection
 error C2110: cannot add two pointers

Answer 1

You can’t dereference void pointer.

If you want to turn them into int* you should do that before dereferencing;

(*(int*)vc) = (*(int*)va) + (*(int*)vb);

But you better be more specific, what exactly you want to do that you call “the following”.