src/test/compile-fail/dst-object-from-unsized-type.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 // Test that we cannot create objects from unsized types.
  12
  13 trait Foo { fn foo(&self) {} }
  14 impl Foo for str {}
  15 impl Foo for [u8] {}
  16
  17 fn test1<T: ?Sized + Foo>(t: &T) {
  18     let u: &Foo = t;
  19     //~^ ERROR `T: std::marker::Sized` is not satisfied
  20 }
  21
  22 fn test2<T: ?Sized + Foo>(t: &T) {
  23     let v: &Foo = t as &Foo;
  24     //~^ ERROR `T: std::marker::Sized` is not satisfied
  25 }
  26
  27 fn test3() {
  28     let _: &[&Foo] = &["hi"];
  29     //~^ ERROR `str: std::marker::Sized` is not satisfied
  30 }
  31
  32 fn test4(x: &[u8]) {
  33     let _: &Foo = x as &Foo;
  34     //~^ ERROR `[u8]: std::marker::Sized` is not satisfied
  35 }
  36
  37 fn main() { }