// Copyright 2012 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. // Test that a type which is covariant with respect to its region // parameter yields an error when used in a contravariant way. // // Note: see variance-regions-*.rs for the tests that check that the // variance inference works in the first place. use std::marker; struct Covariant<'a> { marker: marker::PhantomData } fn use_<'short,'long>(c: Covariant<'long>, s: &'short isize, l: &'long isize, _where:Option<&'short &'long ()>) { // Test whether Covariant<'long> <: Covariant<'short>. Since // 'short <= 'long, this would be true if the Covariant type were // contravariant with respect to its parameter 'a. let _: Covariant<'short> = c; //~ ERROR mismatched types } fn main() {}