I'm using a two-dimensional boost::multi_array to store objects of a custom struct. The problem is that I have a huge amount of these objects so that the index of the array I would need exceeds the range of an integer. Is there any possibility to use long as an index of a multi-array or do you have any other suggestions on how to store a dataset this big and still keep it accessible at a decent speed?
The official documentation states that the index type is unspecified, but looking into the repository, one sees that the definition most likely is typedef std::ptrdiff_t index;
So if you compile for an x86 32-bit system, you will surely run out of addressable memory anyways, so the limited size of indicies is not your real problem. Your only option would be to chose a system with enough memory, which has to be one with more than 2^32 bytes and thus has to be a 64 bit one. 2^64 will be certainly enough to represent the dimensions of your multiarray.