// Copyright 2016 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 or the MIT license // , at your // option. This file may not be copied, modified, or distributed // except according to those terms. // Coherence error results because we do not know whether `T: Foo

` or not // for the second impl. use std::marker::PhantomData; pub trait Foo

{} impl > Foo

for Option {} impl Foo for Option { } //~ ERROR E0119 fn main() {}