// Make sure validation can handle many overlapping shared borrows for different parts of a data structure use std::cell::RefCell; #[allow(unused)] struct Test { a: u32, b: u32, } fn test1() { let t = &mut Test { a: 0, b: 0 }; { let x; { let y = &t.a; x = &t; let _y = *y; } let _x = x.a; } t.b = 42; } fn test2(r: &mut RefCell) { let x = &*r; // releasing write lock, first suspension recorded let mut x_ref = x.borrow_mut(); let x_inner: &mut i32 = &mut *x_ref; // new inner write lock, with same lifetime as outer lock let _x_inner_shr = &*x_inner; // releasing inner write lock, recording suspension let _y = &*r; // second suspension for the outer write lock let _x_inner_shr2 = &*x_inner; // 2nd suspension for inner write lock } fn main() { test1(); test2(&mut RefCell::new(0)); }