array as parameter

[Jonathan M Davis via Digitalmars-d-learn]

On Sat, 07 Jun 2014 20:56:13 +0000
Paul via Digitalmars-d-learn <digitalmars-d-learn at puremagic.com> wrote:

> Dynamic array is really reference. Right? But why modification of
> parameter in this case does not work:
>
> void some_func(string[] s) {
>   s ~= "xxx"; s ~= "yyy";
> }
>
> but this works:
>
> void some_fun(ref string[] s) {
>   s ~= "xxx"; s ~= "yyy";
> }
>
> In the 1st case s is reference too, is not it?

The first case just slices the array, so it refers to the same data, but the
slice itself is a different slice, so if you append to it, it doesn't affect
the original slice, and it could then result in a reallocation so that the two
slices don't even refer to the same data anymore.

You should read this: http://dlang.org/d-array-article.html

- Jonathan M Davis