Passing shared delegates

[Martin Drasar]

On 17.1.2013 12:56, Maxim Fomin wrote:
> Casting away shared in undefined behavior. Although it may be not
> written explicitly in dlang.org, once D will have a standard like C or
> C++, it will be name like so.
> 
> In practice this means that behavior of program is uncertain and may
> result in many consequences. In this case content of arrays may be any
> of 1,2,3,4,5,6.
> ... snip ...
> Note, if you mark functions as @safe, the code will not compile, because
> throwing shared is not allowed in D safe code.

I know about some peculiarities of shared (this thread
http://forum.dlang.org/thread/k7orpj$1tt5$1@digitalmars.com was a good
eye-opener) and tend to avoid it as much as possible and solve my
problems with message passing concurrency, however there are some times
when I had to do some casting and just be careful.

>> What happens when you cast from and to shared? Is there any moving in
>> memory from TLS and back? Or does it just access the memory as if it
>> were in shared space?
> 
> It is implementation specific, but I guess nothing is moved, just a
> variable is reinterpreted.

Ok, good.

> ... snip ...
> You can compile this code and look at addresses and assembly if you are
> interested in implementation details.

Good ol' printf. I should have thought about it. Thanks.

Martin