Binary Compatibility

The current API contains factory methods that let the user specify a memory storage to use (for client optimization so that you don't have to use memory allocators). The problem with this is this is that we don't pass a size of the buffer down to the factory method. This is a consequence of the fact that we expose the size and internal details of internal data structures so that the user could write:

ex:
memcached_st *memcached_create(memcached_st *ptr);

So what is the problem with this? It is a risky business if you do dynamic linking and we change the layout of memcached_st by adding members (and we don't update the library version number)...