Unsafe Rust

Raw pointers

Addresses without borrow tracking: what they are, and why reading through one needs unsafe

What a raw pointer is

A raw pointer is just an address. Unlike a reference it can be null, dangling or aliased, so creating one is safe but reading or writing through it needs unsafe

Writing through a pointer

1fn main() {
2    let mut x = 5;
3    let p = &raw mut x;
4
5    unsafe {
6        *p += 1;
7    }
8    println!("{x}");
9}

$6Visualize in Playground

p holds the address of x. Writing through it changes x in place, with no borrow tracking