src/test/compile-fail/object-safety-generics.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 // Check that we correctly prevent users from making trait objects
  12 // from traits with generic methods, unless `where Self : Sized` is
  13 // present.
  14
  15 trait Bar {
  16     fn bar<T>(&self, t: T);
  17 }
  18
  19 trait Quux {
  20     fn bar<T>(&self, t: T)
  21         where Self : Sized;
  22 }
  23
  24 fn make_bar<T:Bar>(t: &T) -> &Bar {
  25         //~^ ERROR E0038
  26         //~| NOTE method `bar` has generic type parameters
  27         //~| NOTE the trait `Bar` cannot be made into an object
  28     t
  29 }
  30
  31 fn make_bar_explicit<T:Bar>(t: &T) -> &Bar {
  32     //~^ ERROR E0038
  33     //~| NOTE method `bar` has generic type parameters
  34     //~| NOTE the trait `Bar` cannot be made into an object
  35     t as &Bar
  36 }
  37
  38 fn make_quux<T:Quux>(t: &T) -> &Quux {
  39     t
  40 }
  41
  42 fn make_quux_explicit<T:Quux>(t: &T) -> &Quux {
  43     t as &Quux
  44 }
  45
  46 fn main() {
  47 }