src/test/compile-fail/borrowck/borrowck-use-uninitialized-in-cast.rs

   1 // Copyright 2015 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 // revisions: ast mir
  12 //[mir]compile-flags: -Z emit-end-regions -Z borrowck-mir
  13
  14 // Check that we detect unused values that are cast to other things.
  15 // The problem was specified to casting to `*`, as creating unsafe
  16 // pointers was not being fully checked. Issue #20791.
  17
  18 fn main() {
  19     let x: &i32;
  20     let y = x as *const i32; //[ast]~ ERROR use of possibly uninitialized variable: `*x` [E0381]
  21                              //[mir]~^ ERROR (Ast) [E0381]
  22                              //[mir]~| ERROR (Mir) [E0381]
  23 }