rust/tests/ui/coherence/coherence-subtyping.rs

21 lines
555 B
Rust

// Test that two distinct impls which match subtypes of one another
// yield coherence errors (or not) depending on the variance.
//
// Note: This scenario is currently accepted, but as part of the
// universe transition (#56105) may eventually become an error.
//@ check-pass
trait TheTrait {
fn foo(&self) {}
}
impl TheTrait for for<'a, 'b> fn(&'a u8, &'b u8) -> &'a u8 {}
impl TheTrait for for<'a> fn(&'a u8, &'a u8) -> &'a u8 {
//~^ WARN conflicting implementation
//~| WARN the behavior may change in a future release
}
fn main() {}