// 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. // `S` is contravariant with respect to both parameters. struct S<'a, 'b> { f: &'a isize, g: &'b isize, } fn use_<'short,'long>(c: S<'long, 'short>, s: &'short isize, l: &'long isize, _where:Option<&'short &'long ()>) { let _: S<'long, 'short> = c; // OK let _: S<'short, 'short> = c; // OK // Test whether S<_,'short> <: S<_,'long>. Since // 'short <= 'long, this would be true if the Contravariant type were // covariant with respect to its parameter 'a. let _: S<'long, 'long> = c; //~ ERROR mismatched types } fn main() {}