Hey,reading through https://dlang.org/articles/const-faq.html and experimenting a bit:
```
immutable int i = 3;
const(int)* p = &i;
int* q = cast(int*)p;
assert(q == p && p == &i);
writeln(i); // 3
*q = 1; // Why does this have no effect at all? No error
no nothing?!
writeln(i); // 3
```
When changing i to non-immutable the `*q=1` sets i to 1.
There is no error message. The `*q=1` simply has no effect at
all. Also with `const int i`.
Is that intended?
