Simplification of @trusted

[Paul Backus]

On Thursday, 17 June 2021 at 20:25:22 UTC, Ola Fosheim Grøstad 
wrote:
> On Thursday, 17 June 2021 at 19:06:31 UTC, Paul Backus wrote:
>> In order for `get` to have a safe interface, it must not be 
>> possible to call it from `@safe` code with an instance that 
>> has `offset >= 2`. Because of the bug in `size`, it *is* 
>> possible for `@safe` code to call `get` with such an instance. 
>> Therefore, `get` does not have a safe interface.
>
> Yes, but if I make size() @trusted and fix the bug then 
> interface is provably safe?

Assuming [issue 20941][1] is fixed, yes.

[1]: https://issues.dlang.org/show_bug.cgi?id=20941

>
>
>   Also, if I do this, it is probably safe, because of the 
> invariant that is checked?
>
[...]
>
> ```
>     invariant{ assert(0<= offset && offset <=1 ); }
> ```

Yes.