Rust for C-Programmers

25.9 Unsafe Traits

Certain traits in Rust are marked unsafe if an incorrect implementation can lead to undefined behavior. This typically applies to traits involving pointer aliasing, concurrency, or other low-level operations beyond the compiler’s power to verify.

unsafe trait MyUnsafeTrait {
    // Methods or invariants that the implementer must maintain.
}

struct MyType;

unsafe impl MyUnsafeTrait for MyType {
    // Implementation that respects the trait's invariants.
}

Implementing an unsafe trait is a serious responsibility. Violating its requirements can undermine assumptions that other code relies on for safety.