#![feature(fn_traits)] #![feature(unboxed_closures)] struct S; impl Fn(u32) -> u32 for S { //~^ ERROR associated item constraints are not allowed here [E0229] //~| ERROR expected a `FnMut(u32)` closure, found `S` fn call(&self) -> u32 { //~^ ERROR method `call` has 1 parameter but the declaration in trait `call` has 2 5 } } fn main() {}