Re: [Boost-users] Exception when constructing empty list in shared memory (boost::interprocess::list)

Subject: Re: [Boost-users] Exception when constructing empty list in shared memory (boost::interprocess::list)
From: Ion Gaztañaga (igaztanaga_at_[hidden])
Date: 2008-11-22 05:49:05

Roland wrote:
> Hello all (Hi Ion)
> 
> Here's a small piece of code that causes an exception to be thrown (when it
> shouldn't). The environment is MSVC8 (VS2005SP1) with Boost 1.37. The code
> is an adaption of one of the samples in the interprocess documentation.

Thanks for the report. It's a bug. To fix the bug you should modify the 
local copy of list.hpp. As you see there is no protection against an 
empty range insertion:

template<class FwdIterator>
void priv_create_and_insert_nodes
       (const_iterator pos, FwdIterator beg, FwdIterator end,
        allocator_v2, std::forward_iterator_tag)
{
    //Optimized allocation and construction
    this->allocate_many_and_construct
       (beg, std::distance(beg, end), insertion_functor(this->icont(),
       pos.get()));
    }
}

add a test to avoid this:

template<class FwdIterator>
void priv_create_and_insert_nodes
    (const_iterator pos, FwdIterator beg, FwdIterator end, allocator_v2,
     std::forward_iterator_tag)
{
    if(beg != end){
       //Optimized allocation and construction
       this->allocate_many_and_construct
          (beg, std::distance(beg, end), insertion_functor
           (this->icont(), pos.get()));
    }
}

Commited to SVN, revision 49871.

Regards,

Ion