rust/tests/ui/traits/new-solver/object-unsafety.rs
2023-07-03 09:12:15 +02:00

29 lines
881 B
Rust

// compile-flags: -Ztrait-solver=next
trait Setup {
type From: Copy;
}
fn copy<U: Setup + ?Sized>(from: &U::From) -> U::From {
*from
}
pub fn copy_any<T>(t: &T) -> T {
copy::<dyn Setup<From=T>>(t)
//~^ ERROR the type `&<dyn Setup<From = T> as Setup>::From` is not well-formed
//~| ERROR the trait bound `dyn Setup<From = T>: Setup` is not satisfied
//~| ERROR mismatched types
//~| ERROR mismatched types
//~| ERROR the type `<dyn Setup<From = T> as Setup>::From` is not well-formed
//~| ERROR the size for values of type `<dyn Setup<From = T> as Setup>::From` cannot be known at compilation time
// FIXME(-Ztrait-solver=next): These error messages are horrible and some of them
// are even simple fallout from previous error.
}
fn main() {
let x = String::from("Hello, world");
let y = copy_any(&x);
println!("{y}");
}