more const and pointers

void main()
{
    double d = 3.5;
    const double CD = 4.5;
    // const ptr to double
    double *const cptr = &d;  // OK
    double *const cptr = &CD; // Error: not const dbl
    double *const cptr;       // Error: must initialize
    // const ptr to const double
    const double* const cptr2 = &d;  // OK
    const double* const cptr2 = &CD; // OK
    const double* const cptr2;       // Error: must initialize
}