MaybeUninit for safe uninitialized memory

MaybeUninit<T> is the safe way to work with uninitialized memory. It's useful for FFI, performance-critical code, or when you need to initialize large arrays element-by-element. Unlike uninitialized variables (which are UB), MaybeUninit is explicitly designed for this. You write to it via .as_mut_ptr() or .write(), then call .assume_init() once it's fully initialized. The assumption is your responsibility, so it's still unsafe, but it's safer than raw pointers. I use it for zero-copy deserialization or when initializing large fixed-size buffers. It's a low-level tool but essential for certain patterns where you can't afford the overhead of default initialization.