Confusion over what types have value vs reference semantics

[Mike Parker via Digitalmars-d-learn]

On Sunday, 11 September 2016 at 16:10:04 UTC, Mike Parker wrote:

> And here, no memory is allocated. barSlice.ptr is the same as 
> bar.ptr and barSlice.length is the same as bar.length. However, 
> if you append a new element:
>
> barSlice ~= 10;
>
> The GC will allocate memory for a new array and barSlice will 
> no longer point to bar. It will now have four elements.

I should clarify that this holds true for all slices, not just 
slices of static arrays. The key point is that appending to a 
slice will only allocate if the the .capacity property of the 
slice is 0. Slices of static arrays will always have a capacity 
of 0. Slices of slices might not, i.e. there may be room in the 
memory block for more elements.