Arena allocation with alignment-aware bump pointers is the backbone of how LLVM's BumpPtrAllocator handles every IR node during a compilation pass, and how web servers like nginx and per-request handlers in Go's runtime scope allocations to a request's lifetime so the entire arena can be dropped in one O(1) operation instead of walking a free list. Getting the `(offset + align - 1) & ~(align - 1)` alignment trick right here is the exact bit-masking idiom used throughout systems code wherever a type's `_Alignof` must be respected.