Inability to dup/~ for const arrays of class objects

[Peter Williams]

On 30/05/13 16:21, Ali Çehreli wrote:
> On 05/29/2013 06:54 PM, Peter Williams wrote:
>  > Wouldn't a better rule for pass by value be that any changes to
>  > the data part of the array (including assignment to an element) causes
>  > reallocation of the entire data portion.
>
> The type of a slice parameter is not different than a local slice
> variable. Since we wouldn't want an entire copy of the elements due to
> an element mutation:
>
>      int[] whole = // ...;
>      int[] firstHalf = whole[0 .. $/2];
>      firstHalf = 42;    // this should affect whole
>
> Moving the last two lines to a new function should not change meaning:
>
>      int[] whole = // ...;
>      setFirstHalf(whole, 42);  // should still affect whole

I think that setFirstHalf() should only effect whole if it's passed in 
by reference.  I certainly intend to adopt that practice in my D code.

Peter