Possible to pass a member function to spawn?

Steven Schveighoffer schveiguy at yahoo.com
Mon Feb 6 18:33:18 PST 2012

On Mon, 06 Feb 2012 21:26:02 -0500, James Miller <james at aatch.net> wrote:

> It is also worth noting that the reason delegates are not eligible for
> thread spawn is that delegates hold references from outside their
> definition. This means that delegates can hold references to data that
> outside their thread, thus breaking the rule that all data is
> thread-local unless specified otherwise.
> The compiler could try to reason about your program and figure out
> that your "delegate" doesn't actually access cross-thread data, but
> that is very, very hard to prove. D's design is not suited to the
> Actor model, at least not without some modification.

He wants to do a delegate of a method from a shared class, there is no  
unknown context here.  I agree delegate literals should not be eligible.   
Then again, those delegates should not be marked shared.

When I tried to run a simple test, the compiler reported:

Error: template std.concurrency.spawn(T...) cannot deduce template  
function from argument types !()(void delegate() shared)

So clearly, the compiler knows that the delegate is from a shared object.   
This should be doable today...


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