[MaskRay]

I don't follow Zig's development. https://ziglang.org/download/0.15.1/release-notes.html#Motiv... feels vague to me, and linking to a lengthy video isn't very clarifying. Still, I skimmed through it to get a sense of it.

Zig's approach seems to require users to explicitly call flush for any writes. This reminds me of a similar issue in LLVM's `raw_svector_ostream`. Before a 2015 commit https://github.com/llvm/llvm-project/commit/3d1173ba1a53cab0... , it only called flush at the end, which was efficient. That commit changed this, leading to unnecessarily slow performance. To not break existing users, the 2024 pull request https://github.com/llvm/llvm-project/pull/97704 tries to implement a new interface, but the changes would cause significant churn. @aengelke