Immutable woes

[Pelle]

On 09/21/2010 09:29 AM, Bob Cowdery wrote:
>   Hi
>
> I'm stuggling with immutable.
>
> I have a fixed size buffer which is used as a circular buffer of floats
> and is effectively double buffering data I wish to transfer to another
> thread. At an appropriate point I take the top half or bottom half of
> the buffer and send it to another thread.
>
> To do this I need to copy the data to an immutable transfer buffer to
> use in the send. I'm sure this is simple but I can't figure it.
>
> if I say something like:
> float[] xfer = new float[512];
> xfer = buffer[0 .. $/2];
> tid.send(xfer);
>
> it rightly tells me 'thread local data not allowed'. If I make it:
>
> immutable (float)[] xfer;
> xfer = buffer[0 .. $/2];
> tid.send(xfer);
>
> it tells me 'can't implicitly convert float[] to immutable (float)[]'
>
> If I try a float by float copy into xfer it can't because I've said the
> buffer is immutable. In the first example I can't figure out how to
> convert the slice into an immutable copy which I think is what I should
> be doing.
>
> Can someone point me in the right direction.
>
> Thanks
> Bob
>

immutable(float)[] xfer = buffer[0 .. $/2].idup;
tid.send(xfer);

Don't use assumeUnique for non-unique references.