src/test/compile-fail/indexing-requires-a-uint.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 // Make sure that indexing an array is only valid with a `usize`, not any other
  12 // integral type.
  13
  14 fn main() {
  15     fn bar<T>(_: T) {}
  16     [0][0u8]; //~ ERROR: `[_]: std::ops::Index<u8>` is not satisfied
  17
  18     [0][0]; // should infer to be a usize
  19
  20     let i = 0;      // i is an IntVar
  21     [0][i];         // i should be locked to usize
  22     bar::<isize>(i);  // i should not be re-coerced back to an isize
  23     //~^ ERROR: mismatched types
  24 }