-dip1000 @safe scope wrapper

Chris M. chrismohrfeld at comcast.net
Thu Jun 28 14:05:26 UTC 2018


On Thursday, 28 June 2018 at 13:29:58 UTC, vit wrote:
> Hello,
> Is it possible to create scope wrapper initialized by non 
> default constructor with scope parameter?
> something like this:
>
> struct Wrapper{
>     int* p;
>
>     static Wrapper create(scope return int* p)@safe{
>         Wrapper w;
>         w.p = p;
>         return w;
>     }
>
>     /++ This doesn't work:
>     this(scope return int* p)@safe scope{
>         this.p = p;
>     }+/
> }
>
> void main()@safe{
>     scope int i;
>     scope Wrapper w1 = Wrapper.create(&i);
>     scope Wrapper w2 = Wrapper(&i);
> }

I'm not sure why create works in this case either. I get the 
following when I uncomment the constructor

test.d(12): Error: scope variable p assigned to this with longer 
lifetime

Is there a subtle difference I'm missing?




More information about the Digitalmars-d-learn mailing list