There are a lot of data structures where doubling the size of the struct would be a big deal. I've worked on big graphs, where I used similar tricks, because m

There are a lot of data structures where doubling the size of the struct would be a big deal. I've worked on big graphs, where I used similar tricks, because most of the storage of a graph is pointers, and limits of what can be quickly computed are bound by how much of the graph you can get in memory.