| // 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. |
| |
| #![feature(catch_expr)] |
| |
| // This test checks that borrows made and returned inside catch blocks are properly constrained |
| pub fn main() { |
| { |
| // Test that a borrow which *might* be returned still freezes its referent |
| let mut i = 222; |
| let x: Result<&i32, ()> = do catch { |
| Err(())?; |
| &i |
| }; |
| x.ok().cloned(); |
| i = 0; //~ ERROR cannot assign to `i` because it is borrowed |
| let _ = i; |
| } |
| |
| { |
| let x = String::new(); |
| let _y: Result<(), ()> = do catch { |
| Err(())?; |
| ::std::mem::drop(x); |
| }; |
| println!("{}", x); //~ ERROR use of moved value: `x` |
| } |
| |
| { |
| // Test that a borrow which *might* be assigned to an outer variable still freezes |
| // its referent |
| let mut i = 222; |
| let j; |
| let x: Result<(), ()> = do catch { |
| Err(())?; |
| j = &i; |
| }; |
| i = 0; //~ ERROR cannot assign to `i` because it is borrowed |
| let _ = i; |
| } |
| } |
| |