| // Copyright 2012-2018 The Rust Project Developers. See the COPYRIGHT |
| // file at the top-level directory of this distribution and at |
| // http://rust-lang.org/COPYRIGHT. |
| // |
| // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or |
| // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your |
| // option. This file may not be copied, modified, or distributed |
| // except according to those terms. |
| |
| // compile-pass |
| |
| #![feature(const_let)] |
| #![feature(underscore_const_names)] |
| |
| trait Trt {} |
| struct Str {} |
| impl Trt for Str {} |
| |
| macro_rules! check_impl { |
| ($struct:ident,$trait:ident) => { |
| const _ : () = { |
| use std::marker::PhantomData; |
| struct ImplementsTrait<T: $trait>(PhantomData<T>); |
| let _ = ImplementsTrait::<$struct>(PhantomData); |
| () |
| }; |
| } |
| } |
| |
| #[deny(unused)] |
| const _ : () = (); |
| |
| const _ : i32 = 42; |
| const _ : Str = Str{}; |
| |
| check_impl!(Str, Trt); |
| check_impl!(Str, Trt); |
| |
| fn main() { |
| check_impl!(Str, Trt); |
| check_impl!(Str, Trt); |
| } |