// Test that impls for these two types are considered ovelapping: // // * `for<'r> fn(fn(&'r u32))` // * `fn(fn(&'a u32)` where `'a` is free // // This is because, for `'a = 'static`, the two types overlap. // Effectively for them to be equal to you get: // // * `for<'r> fn(fn(&'r u32)) <: fn(fn(&'static u32))` // * true if `exists<'r> { 'r: 'static }` (obviously true) // * `fn(fn(&'static u32)) <: for<'r> fn(fn(&'r u32))` // * true if `forall<'r> { 'static: 'r }` (also true) trait Trait {} impl Trait for for<'r> fn(fn(&'r ())) {} impl<'a> Trait for fn(fn(&'a ())) {} //~^ ERROR conflicting implementations // // Note in particular that we do NOT get a future-compatibility warning // here. This is because the new leak-check proposed in [MCP 295] does not // "error" when these two types are equated. // // [MCP 295]: https://github.com/rust-lang/compiler-team/issues/295 fn main() {}