> assembly-like unsafeness > I don't see why you would need C-style "arbitrary lines before and after the line that will not execute, reads from unrelated memo

> assembly-like unsafeness > I don't see why you would need C-style "arbitrary lines before and after the line that will not execute, reads from unrelated memory addresses will return arbitrary values" UB This reason this happens is because we don't compile things down to obvious assembly, they get optimized. Each of those optimizations requires assumptions to be made about the the code. If you break those assumptions, then the optimizations can result in arbitrary results happening. Those assumptions determine what is and isn't UB. Most languages just don't give the programmer any way to break those assumptions, but languages like C and Rust do. Thus, Rust will always have this 'problem' because it can/will make even more aggressive optimizations then C will, meaning badly written `unsafe` code will have arbitrary behavior and results from the optimizer if the compiler doesn't understand what you're doing.