diff options
4 files changed, 90 insertions, 1 deletions
diff --git a/compiler/rustc_next_trait_solver/src/solve/assembly/mod.rs b/compiler/rustc_next_trait_solver/src/solve/assembly/mod.rs index a2e6ef6f0fe..d58c264841c 100644 --- a/compiler/rustc_next_trait_solver/src/solve/assembly/mod.rs +++ b/compiler/rustc_next_trait_solver/src/solve/assembly/mod.rs @@ -473,7 +473,10 @@ where // fails to reach a fixpoint but ends up getting an error after // running for some additional step. // - // cc trait-system-refactor-initiative#105 + // FIXME(@lcnr): While I believe an error here to be possible, we + // currently don't have any test which actually triggers it. @lqd + // created a minimization for an ICE in typenum, but that one no + // longer fails here. cc trait-system-refactor-initiative#105. let source = CandidateSource::BuiltinImpl(BuiltinImplSource::Misc); let certainty = Certainty::Maybe { cause, opaque_types_jank: OpaqueTypesJank::AllGood }; self.probe_trait_candidate(source) diff --git a/tests/ui/indexing/ambiguity-after-deref-step.rs b/tests/ui/indexing/ambiguity-after-deref-step.rs new file mode 100644 index 00000000000..2dd95eed097 --- /dev/null +++ b/tests/ui/indexing/ambiguity-after-deref-step.rs @@ -0,0 +1,9 @@ +// Regression test making sure that indexing fails with an ambiguity +// error if one of the deref-steps encounters an inference variable. + +fn main() { + let x = &Default::default(); + //~^ ERROR type annotations needed for `&_` + x[1]; + let _: &Vec<()> = x; +} diff --git a/tests/ui/indexing/ambiguity-after-deref-step.stderr b/tests/ui/indexing/ambiguity-after-deref-step.stderr new file mode 100644 index 00000000000..c7ddd4731c7 --- /dev/null +++ b/tests/ui/indexing/ambiguity-after-deref-step.stderr @@ -0,0 +1,17 @@ +error[E0282]: type annotations needed for `&_` + --> $DIR/ambiguity-after-deref-step.rs:5:9 + | +LL | let x = &Default::default(); + | ^ +LL | +LL | x[1]; + | - type must be known at this point + | +help: consider giving `x` an explicit type, where the placeholders `_` are specified + | +LL | let x: &_ = &Default::default(); + | ++++ + +error: aborting due to 1 previous error + +For more information about this error, try `rustc --explain E0282`. diff --git a/tests/ui/traits/next-solver/forced-ambiguity-typenum-ice.rs b/tests/ui/traits/next-solver/forced-ambiguity-typenum-ice.rs new file mode 100644 index 00000000000..679d6b1fb16 --- /dev/null +++ b/tests/ui/traits/next-solver/forced-ambiguity-typenum-ice.rs @@ -0,0 +1,60 @@ +//@ compile-flags: -Znext-solver +//@ check-pass + +// Regression test for trait-system-refactor-initiative#105. We previously encountered +// an ICE in typenum as `forced_ambiguity` failed. While this test no longer causes +// `forced_ambiguity` to error, we still want to use it as a regression test. + +pub struct UInt<U, B> { + _msb: U, + _lsb: B, +} +pub struct B1; +pub trait Sub<Rhs> { + type Output; +} +impl<U, B> Sub<B1> for UInt<UInt<U, B>, B1> { + type Output = (); +} +impl<U> Sub<B1> for UInt<U, ()> +where + U: Sub<B1>, + U::Output: Send, +{ + type Output = (); +} + +pub trait Op<N, R, I> { + fn op(&self) { + unimplemented!() + } +} +trait OpIf<N, R, I> {} + +impl<N, Ur, Br, I> Op<N, UInt<Ur, Br>, I> for () +where + N: Sub<I>, + (): OpIf<N, UInt<UInt<Ur, Br>, N::Output>, I>, +{ +} +impl<N, R, Ui, Bi> OpIf<N, R, UInt<Ui, Bi>> for () +where + UInt<Ui, Bi>: Sub<B1>, + (): Op<N, R, <UInt<Ui, Bi> as Sub<B1>>::Output>, +{ +} +impl<N, R> OpIf<N, R, ()> for () where R: Sub<N> {} + +pub trait Compute { + type Output; +} + +pub fn repro<Ul, Bl>() +where + UInt<Ul, Bl>: Compute, + <UInt<Ul, Bl> as Compute>::Output: Sub<B1>, + (): Op<UInt<(), Bl>, (), ()>, +{ + ().op(); +} +fn main() {} |