rust/tests/ui/on-unimplemented/on-trait.rs
2023-01-11 09:32:08 +00:00

33 lines
894 B
Rust

// ignore-tidy-linelength
#![feature(rustc_attrs)]
pub mod Bar {
#[rustc_on_unimplemented = "test error `{Self}` with `{Bar}` `{Baz}` `{Quux}` in `{Foo}`"]
pub trait Foo<Bar, Baz, Quux> {}
}
use Bar::Foo;
fn foobar<U: Clone, T: Foo<u8, U, u32>>() -> T {
panic!()
}
#[rustc_on_unimplemented="a collection of type `{Self}` cannot be built from an iterator over elements of type `{A}`"]
trait MyFromIterator<A> {
/// Builds a container with elements from an external iterator.
fn my_from_iter<T: Iterator<Item=A>>(iterator: T) -> Self;
}
fn collect<A, I: Iterator<Item=A>, B: MyFromIterator<A>>(it: I) -> B {
MyFromIterator::my_from_iter(it)
}
pub fn main() {
let x = vec![1u8, 2, 3, 4];
let y: Option<Vec<u8>> = collect(x.iter()); // this should give approximately the same error for x.iter().collect()
//~^ ERROR
let x: String = foobar(); //~ ERROR
}