| // Copyright 2017 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. |
| |
| #![feature(generators)] |
| #![feature(optin_builtin_traits)] |
| |
| auto trait Foo {} |
| |
| struct No; |
| |
| impl !Foo for No {} |
| |
| struct A<'a, 'b>(&'a mut bool, &'b mut bool, No); |
| |
| impl<'a, 'b: 'a> Foo for A<'a, 'b> {} |
| |
| struct OnlyFooIfStaticRef(No); |
| impl Foo for &'static OnlyFooIfStaticRef {} |
| |
| struct OnlyFooIfRef(No); |
| impl<'a> Foo for &'a OnlyFooIfRef {} |
| |
| fn assert_foo<T: Foo>(f: T) {} |
| |
| fn main() { |
| // Make sure 'static is erased for generator interiors so we can't match it in trait selection |
| let x: &'static _ = &OnlyFooIfStaticRef(No); |
| let gen = || { |
| let x = x; |
| yield; |
| assert_foo(x); |
| }; |
| assert_foo(gen); //~ ERROR the trait bound `No: Foo` is not satisfied |
| |
| // Allow impls which matches any lifetime |
| let x = &OnlyFooIfRef(No); |
| let gen = || { |
| let x = x; |
| yield; |
| assert_foo(x); |
| }; |
| assert_foo(gen); // ok |
| |
| // Disallow impls which relates lifetimes in the generator interior |
| let gen = || { |
| let a = A(&mut true, &mut true, No); |
| yield; |
| assert_foo(a); |
| }; |
| assert_foo(gen); //~ ERROR the requirement `for<'r, 's> 'r : 's` is not satisfied |
| } |