| // 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 <LICENSE-APACHE or |
| // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your |
| // option. This file may not be copied, modified, or distributed |
| // except according to those terms. |
| |
| // Check that child trait who only has items via its *parent* trait |
| // does cause dropck to inject extra region constraints. |
| |
| #![allow(non_camel_case_types)] |
| |
| trait Parent { fn foo(&self); } |
| trait Child: Parent { } |
| |
| impl Parent for i32 { fn foo(&self) { } } |
| impl<'a> Parent for &'a D_Child<i32> { |
| fn foo(&self) { |
| println!("accessing child value: {}", self.0); |
| } |
| } |
| |
| impl Child for i32 { } |
| impl<'a> Child for &'a D_Child<i32> { } |
| |
| struct D_Child<T:Child>(T); |
| impl <T:Child> Drop for D_Child<T> { fn drop(&mut self) { self.0.foo() } } |
| |
| fn f_child() { |
| // `_d` and `d1` are assigned the *same* lifetime by region inference ... |
| let (_d, d1); |
| |
| d1 = D_Child(1); |
| // ... we store a reference to `d1` within `_d` ... |
| _d = D_Child(&d1); //~ ERROR `d1` does not live long enough |
| |
| // ... dropck *should* complain, because Drop of _d could (and |
| // does) access the already dropped `d1` via the `foo` method. |
| } |
| |
| fn main() { |
| f_child(); |
| } |