> In C the Any type is void. Using the class definitions above this is entirely valid and produces no warnings: > void v; > struct t1 = v;

I assume you mean a pointer to void here. You explicitly cannot have a void value, as void is an incomplete type (it has no size).

  $ gcc -x c - <<<"int main(void) {void a; return 0;}"
  <stdin>: In function ‘main’:
  <stdin>:1:22: error: variable or field ‘a’ declared void

You can have a pointer to void, which works as you describe, though you must also use a pointer to the struct.

  void *v;
  struct t1 *b = v;