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Custom storage class - Look at my code?

PrestoChung · 2011-06-30T16:59:27

Hi I have created a storage class to store arbitrary objects in linear memory. I think this is essentially a memory allocator but it stores a little information about the object allocated (size in bytes, number of objects) This was originally meant to be the method of storing Components in an Entity-System. Usually I hear that the STL is a better idea. The obvious STL analogue is the std::vector. But the problem is how to store references to std::vector elements? If you store a pointer to an element, that pointer may become invalid by re-sizing of the vector. If you store an index, that index may also change. The other problem is storing generic collections of std::vectors. Because it is a template you cannot have a homogenous collection of std::vectors: each one is a different type. That is why this storage class is not a template: if it was a template I could not create a structure such as [source]Storage myStors[10][/source] if Storage is a template<> There are two supplemental classes that are to help manage the allocation and ownership of the elements: Range and Rangeset. Range is just what it sounds like, it is a minimum and maximum value. A Rangeset is a sorted linked-list of Ranges so that ownership of elements need not always be 100% contiguous. The Storage keeps track of which elements are available with it's own Rangeset, which should be disjoint with the Rangesets of the Entities that have ownership of the objects. Again I have found that a situation such as this will be necessary to hold object Entities themselves if I want them to be contiguous in memory: they will require references to parents and children which can't be stored as pointers to std::vector elements because of the aforesaid considerations. Please correct me if I am causing myself too much trouble! Here is a link to the code (about 850 lines): http://dl.dropbox.com/u/78425/stor.h