Revised cache class

From: Rainer Deyke (root_at_[hidden])
Date: 2002-03-11 17:38:12

I have replaced the cache template class at
http://groups.yahoo.com/group/boost/files/cache.zip with a new
version.  The major new feature is that there are strong and weak
handles.  Strong handles ('cache<...>::handle') guarantee that the
referenced object is in the cache and are analogous to
'boost::shared_ptr'.  Weak handles are analogous to 'boost::weak_ptr'
and require conversion to a strong handle before use.

typedef cache<string, bitmap> bitmap_cache_t;
bitmap_cache_t bitmap_cache;
bitmap_cache_t::handle foo = bitmap_cache.get_handle("foo.bmp");
foo->draw();
bitmap_cache_t::weak_handle weak_bar =
bitmap_cache.get_handle("bar.bmp");
bitmap_cache_t::handle bar = weak_bar.get();
bar->draw();

There are various possible improvements in both interface and
implementation.  However, I would like opinions on what I already have
before I start making random improvements.  Is the general design
acceptable?  Is something like this desired in Boost?

--
Rainer Deyke | root_at_[hidden] | http://rainerdeyke.com