On 10/22/07, Scott <cheesy4poofs@cox.net> wrote:
I have a map, declared as:
typedef std::pair<int, HintPage *> PageCachePair; typedef boost::fast_pool_allocator<PageCachePair> PageCacheAllocator; typedef std::map<int, HintPage *, std::less<int>, PageCacheAllocator> PageCache;
The problem is when I try to call:
boost::singleton_pool<boost::fast_pool_allocator_tag, sizeof(PageCachePair)>::purge_memory();
This always returns false. The real problem (of course) is that sizeof(PageCachePair) is incorrect. The real size is determined by the rebind mechanism for the actual map node struct. However, I have no idea how to portably determine that size.
Is it even possible to do this?
I've ran into this before, and there are some old posts on the Mailing List about this. I can't remember the solution off the top of my head, so you may want to do a search, but I'm pretty sure there's no portable way around this. The big problem is that PageCache::allocator_type will still be identical to your typedef, and get_allocator won't help because you won't know the correct type to cast to. --Michael Fawcett