how to initialise const variables

[Adam D. Ruppe via Digitalmars-d-learn]

On Friday, 26 February 2016 at 02:32:44 UTC, Nicholas Wilson 
wrote:
> struct A
> {
>      const (void *) p;
> }
>
> struct B
> {
>     A    a;
>     this(void * _p)
>     {
>         a.p = _p;
>     }
> }
>
> I cannot change the definition of A
> how do I initialise b.a.p?

Use a constructor for A instead of trying to write to one 
specific member:

a = A(_p);

const variable must be initialized in constructors. Structs have 
automatically defined constructors that take all the member 
variables so even if it isn't explicitly written, you can still 
do this.