| // Copyright 2014 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. |
| |
| // Check testing of equality constraints in a higher-ranked context. |
| |
| pub trait TheTrait<T> { |
| type A; |
| |
| fn get(&self, t: T) -> Self::A; |
| } |
| |
| struct IntStruct { |
| x: isize |
| } |
| |
| impl<'a> TheTrait<&'a isize> for IntStruct { |
| type A = &'a isize; |
| |
| fn get(&self, t: &'a isize) -> &'a isize { |
| t |
| } |
| } |
| |
| struct UintStruct { |
| x: isize |
| } |
| |
| impl<'a> TheTrait<&'a isize> for UintStruct { |
| type A = &'a usize; |
| |
| fn get(&self, t: &'a isize) -> &'a usize { |
| panic!() |
| } |
| } |
| |
| struct Tuple { |
| } |
| |
| impl<'a> TheTrait<(&'a isize, &'a isize)> for Tuple { |
| type A = &'a isize; |
| |
| fn get(&self, t: (&'a isize, &'a isize)) -> &'a isize { |
| t.0 |
| } |
| } |
| |
| fn foo<T>() |
| where T : for<'x> TheTrait<&'x isize, A = &'x isize> |
| { |
| // ok for IntStruct, but not UintStruct |
| } |
| |
| fn bar<T>() |
| where T : for<'x> TheTrait<&'x isize, A = &'x usize> |
| { |
| // ok for UintStruct, but not IntStruct |
| } |
| |
| fn tuple_one<T>() |
| where T : for<'x,'y> TheTrait<(&'x isize, &'y isize), A = &'x isize> |
| { |
| // not ok for tuple, two lifetimes and we pick first |
| } |
| |
| fn tuple_two<T>() |
| where T : for<'x,'y> TheTrait<(&'x isize, &'y isize), A = &'y isize> |
| { |
| // not ok for tuple, two lifetimes and we pick second |
| } |
| |
| fn tuple_three<T>() |
| where T : for<'x> TheTrait<(&'x isize, &'x isize), A = &'x isize> |
| { |
| // ok for tuple |
| } |
| |
| fn tuple_four<T>() |
| where T : for<'x,'y> TheTrait<(&'x isize, &'y isize)> |
| { |
| // not ok for tuple, two lifetimes, and lifetime matching is invariant |
| } |
| |
| pub fn main() { |
| foo::<IntStruct>(); |
| foo::<UintStruct>(); //~ ERROR type mismatch |
| |
| bar::<IntStruct>(); //~ ERROR type mismatch |
| bar::<UintStruct>(); |
| |
| tuple_one::<Tuple>(); |
| //~^ ERROR E0277 |
| //~| ERROR type mismatch |
| |
| tuple_two::<Tuple>(); |
| //~^ ERROR E0277 |
| //~| ERROR type mismatch |
| |
| tuple_three::<Tuple>(); |
| |
| tuple_four::<Tuple>(); |
| //~^ ERROR E0277 |
| } |