// Copyright 2012 The Rust Project Developers. See the COPYRIGHT // file at the top-level directory of this distribution and at // http://rust-lang.org/COPYRIGHT. // // Licensed under the Apache License, Version 2.0 or the MIT license // , at your // option. This file may not be copied, modified, or distributed // except according to those terms. #![feature(overloaded_calls)] use std::ops::{FnMut}; struct S { x: int, y: int, } impl FnMut<(),int> for S { extern "rust-call" fn call_mut(&mut self, (): ()) -> int { self.x * self.y } } fn main() { let mut s = S { x: 3, y: 3, }; let ans = s(); assert_eq!(ans, 9); }