Both safe and wrong?

[Luís Marques]

Consider this code:
https://run.dlang.io/is/aw09pD

import std.stdio;

@safe:

const x = 42;
int* y = cast(int*) &x;

void main()
{
     *y = 7;
     writeln(x); // prints 42
}

I'm probably too out of touch of how the safe type system should 
work, but this seems inconsistent. I would expect *either*:

1) Overriding x's const is unsafe and undefined behavior. The 
cast inside a safe block should cause an error. The 42 is fine.

2) As we promised the type system, we didn't modify the 42 
through a const view of that value (x), instead we used a mutable 
view (y). The cast is fine. It should print 7 instead.

But I guess I'm wrong? Please clarify.