Error: cannot implicitly convert expression this.aa of type inout(string[string]) to string[string]

[Robert-D]

On Thursday, 15 March 2018 at 11:33:49 UTC, Simen Kjærås wrote:
> On Thursday, 15 March 2018 at 11:18:48 UTC, Robert-D wrote:
>> [...]
>
>
> This is where things go wrong:
>>     [...]
>
> 'inout' means that this function can keep the const, immutable 
> or mutable status of the type on which the function is called. 
> This means that an inout function has to treat the object as 
> const, because otherwise the function would break the 
> guarantees of immutable and const.
>
> When using inout on a function, you always want to put inout on 
> something else too - either a ref parameter or the return 
> value. In your case, this works:
>
>     inout(S) dup() inout pure {
>     	return inout(S)(aa);
>     }
>
> --
>   Simen

I want the function to create a mutable copy from a const or a 
imutable

Like this:

void main() {
     const S s = S(["": ""]);
     S b = s.dup();
}

How can i do that?