| // 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 call_foo() { |
| foo::<IntStruct>(); |
| foo::<UintStruct>(); //~ ERROR type mismatch |
| } |
| |
| pub fn call_bar() { |
| bar::<IntStruct>(); //~ ERROR type mismatch |
| bar::<UintStruct>(); |
| } |
| |
| pub fn call_tuple_one() { |
| tuple_one::<Tuple>(); |
| //~^ ERROR implementation of `TheTrait` is not general enough |
| //~| ERROR implementation of `TheTrait` is not general enough |
| } |
| |
| pub fn call_tuple_two() { |
| tuple_two::<Tuple>(); |
| //~^ ERROR implementation of `TheTrait` is not general enough |
| //~| ERROR implementation of `TheTrait` is not general enough |
| } |
| |
| pub fn call_tuple_three() { |
| tuple_three::<Tuple>(); |
| } |
| |
| pub fn call_tuple_four() { |
| tuple_four::<Tuple>(); |
| //~^ ERROR implementation of `TheTrait` is not general enough |
| } |
| |
| fn main() {} |