I'm developing some cross-platform software which is intended to run on mobile devices. Both iOS and Android provide low memory warnings. I plan to make a wrapper class that will free cached resources (like textures) when low memory warnings are issued (assuming the resource is not in use). If the resource returns to use, it'll re-cache it, etc... I'm trying to think of what this is called. In .Net, it's similar to a "weak reference" but that only really makes sense when dealing with garbage collection, and since I'm using c++ and shared_ptr, a weak reference already has a meaning which is distinct from the one I'm thinking of. There's also the difference that this class will be able to rebuild the cache when needed. What is this pattern/whatever is called?
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