src/test/compile-fail/non-exhaustive-match.rs

   1 // Copyright 2012 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 #![feature(slice_patterns)]
  12 #![allow(illegal_floating_point_literal_pattern)]
  13
  14 enum t { a, b, }
  15
  16 fn main() {
  17     let x = t::a;
  18     match x { t::b => { } } //~ ERROR non-exhaustive patterns: `a` not covered
  19     match true { //~ ERROR non-exhaustive patterns: `false` not covered
  20       true => {}
  21     }
  22     match Some(10) { //~ ERROR non-exhaustive patterns: `Some(_)` not covered
  23       None => {}
  24     }
  25     match (2, 3, 4) { //~ ERROR non-exhaustive patterns: `(_, _, _)` not covered
  26       (_, _, 4) => {}
  27     }
  28     match (t::a, t::a) { //~ ERROR non-exhaustive patterns: `(a, a)` not covered
  29       (t::a, t::b) => {}
  30       (t::b, t::a) => {}
  31     }
  32     match t::a { //~ ERROR non-exhaustive patterns: `b` not covered
  33       t::a => {}
  34     }
  35     // This is exhaustive, though the algorithm got it wrong at one point
  36     match (t::a, t::b) {
  37       (t::a, _) => {}
  38       (_, t::a) => {}
  39       (t::b, t::b) => {}
  40     }
  41     let vec = vec![Some(42), None, Some(21)];
  42     let vec: &[Option<isize>] = &vec;
  43     match *vec { //~ ERROR non-exhaustive patterns: `[]` not covered
  44         [Some(..), None, ref tail..] => {}
  45         [Some(..), Some(..), ref tail..] => {}
  46         [None] => {}
  47     }
  48     let vec = vec![1];
  49     let vec: &[isize] = &vec;
  50     match *vec {
  51         [_, ref tail..] => (),
  52         [] => ()
  53     }
  54     let vec = vec![0.5f32];
  55     let vec: &[f32] = &vec;
  56     match *vec { //~ ERROR non-exhaustive patterns: `[_, _, _, _]` not covered
  57         [0.1, 0.2, 0.3] => (),
  58         [0.1, 0.2] => (),
  59         [0.1] => (),
  60         [] => ()
  61     }
  62     let vec = vec![Some(42), None, Some(21)];
  63     let vec: &[Option<isize>] = &vec;
  64     match *vec {
  65         [Some(..), None, ref tail..] => {}
  66         [Some(..), Some(..), ref tail..] => {}
  67         [None, None, ref tail..] => {}
  68         [None, Some(..), ref tail..] => {}
  69         [Some(_)] => {}
  70         [None] => {}
  71         [] => {}
  72     }
  73 }