src/test/compile-fail/borrowck/borrowck-anon-fields-tuple.rs

   1 // Copyright 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 // Tests that we are able to distinguish when loans borrow different
  12 // anonymous fields of a tuple vs the same anonymous field.
  13
  14 fn distinct_variant() {
  15     let mut y = (1, 2);
  16
  17     let a = match y {
  18         (ref mut a, _) => a
  19     };
  20
  21     let b = match y {
  22         (_, ref mut b) => b
  23     };
  24
  25     *a += 1;
  26     *b += 1;
  27 }
  28
  29 fn same_variant() {
  30     let mut y = (1, 2);
  31
  32     let a = match y {
  33         (ref mut a, _) => a
  34     };
  35
  36     let b = match y {
  37         (ref mut b, _) => b //~ ERROR cannot borrow
  38     };
  39
  40     *a += 1;
  41     *b += 1;
  42 }
  43
  44 fn main() {
  45 }