#![allow(unused)] fn foo<F>(f: F) where F: Fn() { } fn main() { // Test that this closure is inferred to `FnOnce` because it moves // from `y.0`. This affects the error output (the error is that // the closure implements `FnOnce`, not that it moves from inside // a `Fn` closure.) let y = (vec![1, 2, 3], 0); let c = || drop(y.0); //~ ERROR expected a closure that implements the `Fn` trait foo(c); }