| // 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. |
| |
| // compile-flags: --edition 2018 |
| |
| #![feature(try_blocks)] |
| |
| #![inline(never)] |
| fn do_something_with<T>(_x: T) {} |
| |
| // This test checks that borrows made and returned inside try blocks are properly constrained |
| pub fn main() { |
| { |
| // Test that borrows returned from a try block must be valid for the lifetime of the |
| // result variable |
| let result: Result<(), &str> = try { |
| let my_string = String::from(""); |
| let my_str: & str = & my_string; |
| //~^ ERROR `my_string` does not live long enough |
| Err(my_str) ?; |
| Err("") ?; |
| }; |
| do_something_with(result); |
| } |
| |
| { |
| // Test that borrows returned from try blocks freeze their referent |
| let mut i = 5; |
| let k = &mut i; |
| let mut j: Result<(), &mut i32> = try { |
| Err(k) ?; |
| i = 10; //~ ERROR cannot assign to `i` because it is borrowed |
| }; |
| ::std::mem::drop(k); //~ ERROR use of moved value: `k` |
| i = 40; //~ ERROR cannot assign to `i` because it is borrowed |
| |
| let i_ptr = if let Err(i_ptr) = j { i_ptr } else { panic ! ("") }; |
| *i_ptr = 50; |
| } |
| } |
| |