valid uses of shared

[Artur Skawina]

On 06/08/12 21:30, Artur Skawina wrote:
>>> in this thread, omitting 'static' should cause a build failure; right
>>> now it is accepted, even when written as
>>>
>>>    shared Atomic!int counter;
>>>
>>> The problem? 'shared' is silently dropped. Move the counter from a struct
>>> into a function after realizing it's only accessed from one place, forget
>>> to add 'static' - and the result will compile w/o even a warning.
>>
>> The difference is that static is not a type constructor.
> 
> The problem is that 'shared' is lost, resulting in an incorrect program.
> When you explicitly declare something as shared the compiler better treat
> it as such, or fail to compile it; silently changing the meaning is never
> acceptable.

That was misleading; "shared" isn't actually lost, but as the variable is
placed on the stack it becomes effectively thread local, which can be very
unintuitive. But i can't think of an easy way to prevent this mistake, while
still allowing shared data to be placed on the stack. And the latter can
be useful sometimes...

artur