rust/tests/ui/traits/suggest-where-clause.rs
2023-01-11 09:32:08 +00:00

37 lines
866 B
Rust

use std::mem;
struct Misc<T:?Sized>(T);
fn check<T: Iterator, U: ?Sized>() {
// suggest a where-clause, if needed
mem::size_of::<U>();
//~^ ERROR the size for values of type
mem::size_of::<Misc<U>>();
//~^ ERROR the size for values of type
// ... even if T occurs as a type parameter
<u64 as From<T>>::from;
//~^ ERROR `u64: From<T>` is not satisfied
<u64 as From<<T as Iterator>::Item>>::from;
//~^ ERROR `u64: From<<T as Iterator>::Item>` is not satisfied
// ... but not if there are inference variables
<Misc<_> as From<T>>::from;
//~^ ERROR `Misc<_>: From<T>` is not satisfied
// ... and also not if the error is not related to the type
mem::size_of::<[T]>();
//~^ ERROR the size for values of type
mem::size_of::<[&U]>();
//~^ ERROR the size for values of type
}
fn main() {
}