rust/tests/ui/associated-types/defaults-cyclic-fail-2.rs

42 lines
888 B
Rust

#![feature(associated_type_defaults)]
// A more complex version of `defaults-cyclic-fail-1.rs`, with non-trivial defaults.
// Having a cycle in assoc. type defaults is okay...
trait Tr {
type A = Vec<Self::B>;
type B = Box<Self::A>;
}
impl Tr for () {}
impl Tr for u8 {
type A = u8;
}
impl Tr for u16 {
type B = ();
}
impl Tr for u32 {
type A = ();
type B = u8;
}
impl Tr for bool {
type A = Box<Self::B>;
//~^ ERROR overflow evaluating the requirement `<bool as Tr>::A == _`
}
// (the error is shown twice for some reason)
impl Tr for usize {
type B = &'static Self::A;
//~^ ERROR overflow evaluating the requirement `<usize as Tr>::B == _`
}
fn main() {
// We don't check that the types project correctly because the cycle errors stop compilation
// before `main` is type-checked.
// `defaults-cyclic-pass-2.rs` does this.
}