> You don't call 'struct_free(obj)' (there isn't even such a function), instead you call 'arena_reset(arena)' once. Stop thinking about individual object lifeti

> You don't call 'struct_free(obj)' (there isn't even such a function), instead you call 'arena_reset(arena)' once. Stop thinking about individual object lifetimes, start thinking about arenas as 'lifetime buckets' :) Yes, so you can use RAII for the arena if needed. The problem is not RAII itself, is where it is applied. And having a manual "arena_reset" function instead of a RAII-based "Arena" abstraction is objectively inferior as anyone could forget to call "arena_reset" while RAII would enforce the clean-up.