Comment by andriy_koval

> You allocate off heap memory and dump data into it. With modern Java classes like Arena, MemoryLayout, and VarHandle it's honestly a lot like C structs.

my opinion is that no, it is not, declaring and using C struct is 20x times more transparent, cost efficient and predictable. And that's we talking about C raw stucts, which has lots of additional ergonomics/safety/expression improvements in both c++ and rust on top of it.