rust/src/test/compile-fail/variance-contravariant-self-trait-match.rs
Niko Matsakis 38fdd50e0b Remove *most* mentions of phantom fns and variance on traits. Leave some
comments and also leave the entries in the variance tables for now.
2015-04-02 13:25:06 -04:00

38 lines
1.0 KiB
Rust

// Copyright 2015 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.
#![allow(dead_code)]
// Test that even when `Self` is only used in contravariant position, it
// is treated as invariant.
trait Get {
fn get(&self);
}
fn get_min_from_max<'min, 'max, G>()
where 'max : 'min, G : 'max, &'max G : Get
{
impls_get::<&'min G>(); //~ ERROR mismatched types
}
fn get_max_from_min<'min, 'max, G>()
where 'max : 'min, G : 'max, &'min G : Get
{
// Previously OK, but now error because traits are invariant with
// respect to all inputs.
impls_get::<&'max G>(); //~ ERROR mismatched types
}
fn impls_get<G>() where G : Get { }
fn main() { }