| warning: the feature `specialization` is incomplete and may not be safe to use and/or cause compiler crashes |
| --> $DIR/issue-39448.rs:1:12 |
| | |
| LL | #![feature(specialization)] |
| | ^^^^^^^^^^^^^^ |
| | |
| = note: see issue #31844 <https://github.com/rust-lang/rust/issues/31844> for more information |
| = help: consider using `min_specialization` instead, which is more stable and complete |
| = note: `#[warn(incomplete_features)]` on by default |
| |
| error[E0391]: cycle detected when computing whether impls specialize one another |
| --> $DIR/issue-39448.rs:24:1 |
| | |
| LL | impl<T: A, U: A + FromA<T>> FromA<T> for U { |
| | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ |
| | |
| = note: ...which requires evaluating trait selection obligation `u16: FromA<u8>`... |
| = note: ...which again requires computing whether impls specialize one another, completing the cycle |
| note: cycle used when building specialization graph of trait `FromA` |
| --> $DIR/issue-39448.rs:20:1 |
| | |
| LL | trait FromA<T> { |
| | ^^^^^^^^^^^^^^ |
| = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information |
| |
| error: aborting due to 1 previous error; 1 warning emitted |
| |
| For more information about this error, try `rustc --explain E0391`. |
