If you ever start from something like this, you should be asking a lot of more-basic questions first, such as: 1. Why is the goal to put everything in one bloc

If you ever start from something like this, you should be asking a lot of more-basic questions first, such as: 1. Why is the goal to put everything in one block with a single allocation? Could everything still work if they were separated? 2. What do Vector2 and Vector3 look like? What if they say "int a, b" and "int a, b, c" respectively? If a perfectly-aligned "new int[total]" would have fixed the problem, it should have been tried from the start and the code refactored accordingly to not necessarily use structure types to look up the data. 3. Conversely, are Vector2 and Vector3 complex classes with special constructors (or equally important, could they someday become that way)? If so, even a "fixed" memory-allocation solution will be equally fragile to maintain because there is a responsibility to ensure that constructors are called correctly. 4. What is the memory profile of the rest of the application, e.g. how many Mesh objects themselves are created and is the entire approach to managing Mesh objects wrong? Maybe the focus on optimizing one piece has missed an entire problem somewhere else that is more fundamental. Clearly the original code has bugs but it is also only 14 lines, the fixes for the bugs are straightforward and the right solution (after other analysis) may well have been to remove the code entirely instead of doing the same thing in a different way. Beware of the tendency to "fix" things without looking more deeply at the actual problem.