rust/tests/ui/borrowck/two-phase-sneaky.rs

16 lines
509 B
Rust

// This is the first counter-example from Niko's blog post
// smallcultfollowing.com/babysteps/blog/2017/03/01/nested-method-calls-via-two-phase-borrowing/
// of a danger for code to crash if we just turned off the check for whether
// a mutable-borrow aliases another borrow.
fn main() {
let mut v: Vec<String> = vec![format!("Hello, ")];
v[0].push_str({
v.push(format!("foo"));
//~^ ERROR cannot borrow `v` as mutable more than once at a time [E0499]
"World!"
});
}