E0796.md

Reference of mutable static.

Erroneous code example:

static mut X: i32 = 23;
static mut Y: i32 = 24;

unsafe {
  let y = &X;
  let ref x = X;
  let (x, y) = (&X, &Y);
  foo(&X);
}

fn foo<'a>(_x: &'a i32) {}

Mutable statics can be written to by multiple threads: aliasing violations or data races will cause undefined behavior.

Reference of mutable static is a hard error from 2024 edition.