Cannot take the .keys of shared AA. Is this a regression in 2.087 or a feature?

[Jonathan M Davis]

On Friday, August 16, 2019 2:16:31 AM MDT Piotr Mitana via Digitalmars-d-
learn wrote:
> On Thursday, 15 August 2019 at 19:51:30 UTC, Jonathan M Davis
>
> wrote:
> > Not being able to implicitly convert to const is a bit odd, but
> > arguably, nothing should ever be called on a shared AA anyway.
> > If an operation isn't thread-safe, then it shouldn't work with
> > shared. To use a shared object safely, you have to protect
> > access to it with a mutex or some other synchronization
> > mechanism, after which you would normally cast away shared to
> > operate on the object as thread-local while the lock is in
> > place and then release the lock when you're done (also making
> > sure that no thread-local references exist when the lock is
> > released). Because keys is not at all thread-safe, I'd strongly
> > argue that it should not work on a shared AA, and if it does,
> > that's a bug.
>
> OK, I get the point. So I should go with something similar to
> this, right?
>
> import core.sync.mutex;
> import std;
>
> shared(string[string]) dict;
> shared(Mutex) mtx;
>
> shared static this()
> {
>      mtx = new shared Mutex;
> }
>
> void main()
> {
>      mtx.lock;
>      (cast(string[string]) dict).keys;
>      mtx.unlock;
> }
>
> Or I could use synchronized, if dict was inside a class. Thank
> you!

Yes. Or you can use synchronized blocks. e.g.

    synchronized(mtx)
    {
        (cast(string[string]) dict).keys;
    }

- Jonathan M Davis