Re: [Boost-users] Possibly too newbie a question?

Subject: Re: [Boost-users] Possibly too newbie a question?
From: Gevorg Voskanyan (v_gevorg_at_[hidden])
Date: 2010-03-17 17:30:29

Eric Whitcombe wrote:
>>>    I am stepping through interprocess shared memory code and I was a little 
>>>    confused by the offset_ptr code that I was 
>>>    hitting*. I cannot figure out how that is specified to the template of rbtree_best_fit. I see in boost/interprocess/interprocess_fwd.hpp the declaration 
>>>    of managed_shared_memory by typedef'ing basic_managed_shared_memory with rbtree_best_fit<mutex_family> as the 
>>> AllocationAlgorithm argument but I can't figure out how offset_ptr is is supplied as the VoidPointer >>>    argument to the rbtree_best_fit template. That 
>>>    template has 3 arguments but the forward declaration only provides one. Are 
>>>    the other two somehow inferred? If so, how? 

rbtree_best_fit<mutex_family> works because rbtree_best_fit
class template's declaration specifies default arguments for
VoidMutex and MemAlignment template parameters, shown here:
template<class MutexFamily, class VoidMutex = offset_ptr<void>, std::size_t MemAlignment = 0>
class rbtree_best_fit;

So rbtree_best_fit<mutex_family> is equivalent to
rbtree_best_fit<mutex_family, offset_ptr<void>, 0>

Does that answer your question, or have I misunderstood it?

HTH,
Gevorg