src/test/ui/nll/return_from_loop.rs

   1 // Copyright 2012-2016 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 // Basic test for liveness constraints: the region (`R1`) that appears
  12 // in the type of `p` includes the points after `&v[0]` up to (but not
  13 // including) the call to `use_x`. The `else` branch is not included.
  14
  15 // compile-flags:-Zborrowck=compare
  16
  17 #![allow(warnings)]
  18 #![feature(rustc_attrs)]
  19
  20 struct MyStruct {
  21     field: String
  22 }
  23
  24 fn main() {
  25 }
  26
  27 fn nll_fail() {
  28     let mut my_struct = MyStruct { field: format!("Hello") };
  29
  30     let value = &mut my_struct.field;
  31     loop {
  32         my_struct.field.push_str("Hello, world!");
  33         //~^ ERROR (Ast) [E0499]
  34         //~| ERROR (Mir) [E0499]
  35         value.len();
  36         return;
  37     }
  38 }
  39
  40 fn nll_ok() {
  41     let mut my_struct = MyStruct { field: format!("Hello") };
  42
  43     let value = &mut my_struct.field;
  44     loop {
  45         my_struct.field.push_str("Hello, world!");
  46         //~^ ERROR (Ast) [E0499]
  47         return;
  48     }
  49 }