// Copyright 2015 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. // Demonstrate that a type param in negative position causes dropck to reject code // that might indirectly access previously dropped value. // // Compare with run-pass/issue28498-ugeh-with-passed-to-fn.rs #[derive(Debug)] struct ScribbleOnDrop(String); impl Drop for ScribbleOnDrop { fn drop(&mut self) { self.0 = format!("DROPPED"); } } struct Foo(u32, T, Box fn(&'r T) -> String>); impl Drop for Foo { fn drop(&mut self) { // Use of `unsafe_destructor_blind_to_params` is unsound, // because we pass `T` to the callback in `self.2` // below, and thus potentially read from borrowed data. println!("Dropping Foo({}, {})", self.0, (self.2)(&self.1)); } } fn callback(s: & &ScribbleOnDrop) -> String { format!("{:?}", s) } fn main() { let (last_dropped, foo0); let (foo1, first_dropped); last_dropped = ScribbleOnDrop(format!("last")); first_dropped = ScribbleOnDrop(format!("first")); foo0 = Foo(0, &last_dropped, Box::new(callback)); foo1 = Foo(1, &first_dropped, Box::new(callback)); println!("foo0.1: {:?} foo1.1: {:?}", foo0.1, foo1.1); } //~^ ERROR `last_dropped` does not live long enough //~| ERROR `first_dropped` does not live long enough