On 07/05/2018 09:43 PM, Ivo Maffei wrote:
class Foo {
private static Foo[] fooSlice = new Foo[0]; //private static slice
static immutable Foo[] getFooList() { //static method returning an
immutable slice
return fooSlice;
}
}
However when compiling with dub I get the following error:
Error: function `main.Foo.getFooList` without this cannot be immutable
If you want to return an `immutable Foo[]`, you have to write the
signature like this:
static immutable(Foo[]) getFooList()
Otherwise, the `immutable` qualifier applies to the method itself
instead of the `Foo[]` return type. But a static method can't be
immutable, so you get the error.
But it won't work even if you fix that, because mutable doesn't convert
to immutable like that.
`immutable` means that the data can't ever change. Not even the owning
Foo is allowed to change it. If you want to disallow changes from
outside, but still allow the owning Foo to make changes, use `const`:
static const(Foo[]) getFooList()
