@safe pointer value modification

[Jacob Shtokolov via Digitalmars-d]

Hi,

According to the docs: https://dlang.org/spec/memory-safe-d.html
Memory-safe code cannot use certain language features, such as:

   Casts that break the type system.
   Modification of pointer values.
   Taking the address of a local variable or function parameter.

So, modification of pointer values is prohibited (if I understand 
this sentence correctly).
However, this code compiles (and will cause a segfault of 
course): https://run.dlang.io/is/HrUKMy

    import std.stdio;

    @safe void main()
    {
        int *a;
        *a = 10;

        writeln(a);
    }

I'm still learning D so very likely misunderstood something, but 
isn't that a bug?

Thanks!