Multiple return values in C at the cost of one weird input parameter(github.com)

  typedef struct { int x; int y; } foo_result_t;
  foo_result_t foo(int a, int b) {
     return (foo_result_t){ a*a, a/b };
  }
  int main(void) {
     foo_result_t a = foo(40,2);
  }

  struct { int x; int y; } foo(int a, int b)
  {
     typeof(foo(a,b)) out = { a*a, a/b };
     return out;
  }
  int main(void) {
     __auto_type a = foo(40,2);
  }

    struct Foo foo = return_foo();

    struct Foo foo;
    return_foo(&foo);

   return out;
   (void)zero;