src/test/run-pass/regions-refcell.rs

   1 // Copyright 2012-2014 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 // This is a regression test for something that only came up while
  12 // attempting to bootstrap librustc with new destructor lifetime
  13 // semantics.
  14
  15
  16 use std::collections::HashMap;
  17 use std::cell::RefCell;
  18
  19 // This version does not yet work (associated type issues)...
  20 #[cfg(cannot_use_this_yet)]
  21 fn foo<'a>(map: RefCell<HashMap<&'static str, &'a [u8]>>) {
  22     let one = [1];
  23     assert_eq!(map.borrow().get("one"), Some(&one[..]));
  24 }
  25
  26 #[cfg(cannot_use_this_yet_either)]
  27 // ... and this version does not work (the lifetime of `one` is
  28 // supposed to match the lifetime `'a`) ...
  29 fn foo<'a>(map: RefCell<HashMap<&'static str, &'a [u8]>>) {
  30     let one = [1];
  31     assert_eq!(map.borrow().get("one"), Some(&&one[..]));
  32 }
  33
  34 #[cfg(all(not(cannot_use_this_yet),not(cannot_use_this_yet_either)))]
  35 fn foo<'a>(map: RefCell<HashMap<&'static str, &'a [u8]>>) {
  36     // ...so instead we walk through the trivial slice and make sure
  37     // it contains the element we expect.
  38
  39     for (i, &x) in map.borrow().get("one").unwrap().iter().enumerate() {
  40         assert_eq!((i, x), (0, 1));
  41     }
  42 }
  43
  44 fn main() {
  45     let zer = [0];
  46     let one = [1];
  47     let two = [2];
  48     let mut map = HashMap::new();
  49     map.insert("zero", &zer[..]);
  50     map.insert("one",  &one[..]);
  51     map.insert("two",  &two[..]);
  52     let map = RefCell::new(map);
  53     foo(map);
  54 }