This annotation would be useless, because it would infect ~99% of your codebase. All IO is implemented as unsafe FFI calls or unsafe inline assembly somewhere d

This annotation would be useless, because it would infect ~99% of your codebase. All IO is implemented as unsafe FFI calls or unsafe inline assembly somewhere down the stack. And even "pure" types like Box, Option, Vec have a lot of unsafe in their implementations. At some point these standard implementations just have to talk to an allocator which is implemented unsafely (obviously), or they have to construct a slice [1], etc. Would you make an exception for the standard library and why? I think, this just doesn't make sense. It's all unsafe somewhere down the stack. [1] https://doc.rust-lang.org/std/slice/fn.from_raw_parts.html https://doc.rust-lang.org/std/slice/fn.from_raw_parts.html