// Copyright 2016 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. //! Test that #[derive(Copy, Clone)] produces a shallow copy //! even when a member violates RFC 1521 #[macro_use] extern crate derivative; use std::sync::atomic::{AtomicBool, ATOMIC_BOOL_INIT, Ordering}; /// A struct that pretends to be Copy, but actually does something /// in its Clone impl #[derive(Copy)] struct Liar; /// Static cooperating with the rogue Clone impl static CLONED: AtomicBool = ATOMIC_BOOL_INIT; impl Clone for Liar { fn clone(&self) -> Self { // this makes Clone vs Copy observable CLONED.store(true, Ordering::SeqCst); *self } } /// This struct is actually Copy... at least, it thinks it is! #[derive(Copy, Clone)] struct TheirTheir(Liar); #[derive(Derivative)] #[derivative(Copy, Clone)] struct OurOur1(Liar); #[derive(Derivative)] #[derivative(Clone, Copy)] struct OurOur2(Liar); #[derive(Copy)] #[derive(Derivative)] #[derivative(Clone)] struct TheirOur1(Liar); #[derive(Copy)] #[derive(Derivative)] #[derivative(Clone)] struct TheirOur2(Liar); #[test] fn main() { let _ = TheirTheir(Liar).clone(); assert!(!CLONED.load(Ordering::SeqCst), "TheirTheir"); let _ = OurOur1(Liar).clone(); assert!(!CLONED.load(Ordering::SeqCst), "OurOur1"); let _ = OurOur2(Liar).clone(); assert!(!CLONED.load(Ordering::SeqCst), "OurOur2"); // Ideally this would work the same, just testing that the behaviour does not change: CLONED.store(false, Ordering::SeqCst); let _ = TheirOur1(Liar).clone(); assert!(CLONED.load(Ordering::SeqCst), "TheirOur1"); CLONED.store(false, Ordering::SeqCst); let _ = TheirOur2(Liar).clone(); assert!(CLONED.load(Ordering::SeqCst), "TheirOur2"); }