src/test/compile-fail/trait-suggest-where-clause.rs

   1 // Copyright 2016 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 use std::mem;
  12
  13 struct Misc<T:?Sized>(T);
  14
  15 fn check<T: Iterator, U: ?Sized>() {
  16     // suggest a where-clause, if needed
  17     mem::size_of::<U>();
  18     //~^ ERROR `U: std::marker::Sized` is not satisfied
  19     //~| HELP E0277
  20     //~| HELP consider adding a `where U: std::marker::Sized` bound
  21     //~| NOTE required by `std::mem::size_of`
  22
  23     mem::size_of::<Misc<U>>();
  24     //~^ ERROR `U: std::marker::Sized` is not satisfied
  25     //~| HELP E0277
  26     //~| HELP consider adding a `where U: std::marker::Sized` bound
  27     //~| NOTE required because it appears within the type `Misc<U>`
  28     //~| NOTE required by `std::mem::size_of`
  29
  30     // ... even if T occurs as a type parameter
  31
  32     <u64 as From<T>>::from;
  33     //~^ ERROR `u64: std::convert::From<T>` is not satisfied
  34     //~| HELP E0277
  35     //~| HELP consider adding a `where u64: std::convert::From<T>` bound
  36     //~| NOTE required by `std::convert::From::from`
  37
  38     <u64 as From<<T as Iterator>::Item>>::from;
  39     //~^ ERROR `u64: std::convert::From<<T as std::iter::Iterator>::Item>` is not satisfied
  40     //~| HELP E0277
  41     //~| HELP consider adding a `where u64:
  42     //~| NOTE required by `std::convert::From::from`
  43
  44     // ... but not if there are inference variables
  45
  46     <Misc<_> as From<T>>::from;
  47     //~^ ERROR `Misc<_>: std::convert::From<T>` is not satisfied
  48     //~| HELP E0277
  49     //~| NOTE required by `std::convert::From::from`
  50
  51     // ... and also not if the error is not related to the type
  52
  53     mem::size_of::<[T]>();
  54     //~^ ERROR `[T]: std::marker::Sized` is not satisfied
  55     //~| HELP E0277
  56     //~| NOTE `[T]` does not have a constant size
  57     //~| NOTE required by `std::mem::size_of`
  58
  59     mem::size_of::<[&U]>();
  60     //~^ ERROR `[&U]: std::marker::Sized` is not satisfied
  61     //~| HELP E0277
  62     //~| NOTE `[&U]` does not have a constant size
  63     //~| NOTE required by `std::mem::size_of`
  64 }
  65
  66 fn main() {
  67 }