rust/src/test/ui/borrowck/borrowck-swap-mut-base-ptr.rs
2020-08-30 18:45:07 +03:00

23 lines
486 B
Rust

// Test that attempt to swap `&mut` pointer while pointee is borrowed
// yields an error.
//
// Example from compiler/rustc_borrowck/borrowck/README.md
use std::mem::swap;
fn foo<'a>(mut t0: &'a mut isize,
mut t1: &'a mut isize) {
let p: &isize = &*t0; // Freezes `*t0`
swap(&mut t0, &mut t1); //~ ERROR cannot borrow `t0`
*t1 = 22;
p.use_ref();
}
fn main() {
}
trait Fake { fn use_mut(&mut self) { } fn use_ref(&self) { } }
impl<T> Fake for T { }