// Tests that two closures cannot simultaneously have mutable // access to the variable, whether that mutable access be used // for direct assignment or for taking mutable ref. Issue #6801. #![feature(on_unimplemented)] #[rustc_on_unimplemented( //~ ERROR `#[rustc_on_unimplemented]` requires a value message="the message" label="the label" //~ ERROR expected one of `)` or `,`, found `label` )] trait T {} fn main() { }