#![feature(unboxed_closures, tuple_trait)] // Tests that we can't move out of an unboxed closure environment // if the upvar is captured by ref or the closure takes self by // reference. fn to_fn>(f: F) -> F { f } fn to_fn_mut>(f: F) -> F { f } fn to_fn_once>(f: F) -> F { f } fn main() { // By-ref cases { let x = Box::new(0); let f = to_fn(|| drop(x)); //~ ERROR cannot move } { let x = Box::new(0); let f = to_fn_mut(|| drop(x)); //~ ERROR cannot move } { let x = Box::new(0); let f = to_fn_once(|| drop(x)); // OK -- FnOnce } // By-value cases { let x = Box::new(0); let f = to_fn(move || drop(x)); //~ ERROR cannot move } { let x = Box::new(0); let f = to_fn_mut(move || drop(x)); //~ ERROR cannot move } { let x = Box::new(0); let f = to_fn_once(move || drop(x)); // this one is ok } }