Re: [boost] [spirit] Two failures caused by thread lib updated?

From: Hartmut Kaiser (hartmut.kaiser_at_[hidden])
Date: 2007-10-27 18:15:16

Peter Dimov wrote:

> > the multi platform failures observed for grammar_mt_tests and 
> > owi_mt_tests seem to correlate to the recent thread lib update:
> >
> > cxx: Error: ../boost/thread/pthread/thread.hpp, line 139: 
> call of an 
> > object
> >           of a class type without appropriate operator() or 
> conversion
> >           functions to pointer-to-function type (badcallclsobj)
> >           detected during instantiation of "void
> >                     boost::thread::thread_data<F>::run() [with
> >
> > F=boost::reference_wrapper<single_grammar_object_task>]"
> >                 f();
> > ----------------^
> >
> > Anyone knows what's going on?
> 
> I think I do. The new Boost.Threads implements the proposed 
> standard interface where F is expected to be a function 
> object; std::reference_wrapper is, but 
> boost::reference_wrapper isn't. The old Boost.Threads did not 
> suffer from this problem since it stored F in a 
> boost::function, which automatically recognizes 
> reference_wrapper and "dereferences" it before the call.
> 
> This can be fixed on the user side by wrapping the 
> reference_wrapper in a boost::bind, or it can be fixed on the 
> Boost.Threads side. The third option, making 
> boost::reference_wrapper callable, is a very risky change 
> that I would advise against. 

I strongly object against silently changing the Boost.Thread
interface/semantics. So I'ld vote for 2)

Regards Hartmut