src/test/compile-fail/borrowck/borrowck-use-uninitialized-in-cast-trait.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 // Variation on `borrowck-use-uninitialized-in-cast` in which we do a
  12 // trait cast from an uninitialized source. Issue #20791.
  13
  14 trait Foo { fn dummy(&self) { } }
  15 impl Foo for i32 { }
  16
  17 fn main() {
  18     let x: &i32;
  19     let y = x as *const Foo; //~ ERROR use of possibly uninitialized variable: `*x`
  20 }