| // Copyright 2017 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. |
| |
| use std::fmt; |
| |
| fn foo() -> Box<impl fmt::Debug+?Sized> { |
| let x : Box<[u8]> = Box::new([0]); |
| x |
| } |
| fn bar() -> Box<impl fmt::Debug+?Sized> { |
| let y: Box<fmt::Debug> = Box::new([0]); |
| y |
| } |
| |
| fn main() { |
| let f = foo(); |
| let b = bar(); |
| |
| // this is an `*mut [u8]` in practice |
| let f_raw : *mut _ = Box::into_raw(f); |
| // this is an `*mut fmt::Debug` in practice |
| let mut b_raw = Box::into_raw(b); |
| // ... and they should not be mixable |
| b_raw = f_raw as *mut _; //~ ERROR is invalid |
| } |
