rust/tests/ui/nll/issue-27282-reborrow-ref-mut-in-guard.rs
2023-01-11 09:32:08 +00:00

31 lines
1.2 KiB
Rust

// Issue 27282: This is a variation on issue-27282-move-ref-mut-into-guard.rs
//
// It reborrows instead of moving the `ref mut` pattern borrow. This
// means that our conservative check for mutation in guards will
// reject it. But I want to make sure that we continue to reject it
// (under NLL) even when that conservative check goes away.
#![feature(if_let_guard)]
fn main() {
let mut b = &mut true;
match b {
&mut false => {},
ref mut r if { (|| { let bar = &mut *r; **bar = false; })();
//~^ ERROR cannot borrow `r` as mutable, as it is immutable for the pattern guard
false } => { &mut *r; },
&mut true => { println!("You might think we should get here"); },
_ => panic!("surely we could never get here, since rustc warns it is unreachable."),
}
let mut b = &mut true;
match b {
&mut false => {},
ref mut r if let Some(()) = { (|| { let bar = &mut *r; **bar = false; })();
//~^ ERROR cannot borrow `r` as mutable, as it is immutable for the pattern guard
None } => { &mut *r; },
&mut true => {},
_ => {},
}
}