alt Hacker News> But the bug is still almost always in an unsafe block.
That's entirely dependent on how you write your Rust code. If you're derefing an invalid pointer then the bug is usually in how you calculated that pointer value, but the only part that actually requires 'unsafe' is the deref, not the bugged pointer calculation.
Now in properly written Rust code you should be marking all of that code as 'unsafe' in that case and documenting what invariants need to be maintained, but that's entirely on you to do. The only part the compiler actually enforces is that you mark the specific spots where you make use of the operations that 'unsafe' allows.
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I think this point gets missed too often in the face of technical things the Rust compiler does.
There was a world where everyone just used the unsafe keyword everywhere, and Rust code crashed & had memory issues all the time.
The big thing Rust did wasn't invent borrow checking or memory safety; it's the ease of use, the defaults, and the social aspect of "if unsafe is used, a memory bug is in the unsafe part".
> The only part the compiler actually enforces is that you mark the specific spots where you make use of the operations that 'unsafe' allows.
Yes, I wish there was a way to mark code as unsafe without also allowing unsafe operations. Its quite common I have some "safe" code that generates values which are eventually used in an unsafe block. If the "safe" code is wrong, my unsafe code will fail in memory-unsafe ways. But there's currently no way to annotate this sort of "safe" code. Rust provides the unsafe keyword - but that keyword is generally reserved for code which needs to actually make unsafe operations (like derefing pointers or calling other unsafe functions).