diff options
Diffstat (limited to 'tests')
4 files changed, 87 insertions, 4 deletions
diff --git a/tests/ui/traits/next-solver/cycles/inductive-cycle-but-err.rs b/tests/ui/traits/next-solver/cycles/inductive-cycle-but-err.rs index b0c778e7f57..754fc872e45 100644 --- a/tests/ui/traits/next-solver/cycles/inductive-cycle-but-err.rs +++ b/tests/ui/traits/next-solver/cycles/inductive-cycle-but-err.rs @@ -34,9 +34,17 @@ where MultipleNested: Trait, {} +// We ignore the trivially true global where-bounds when checking that this +// impl is well-formed, meaning that we depend on `MultipleNested: Trait` when +// recursively proving `MultipleCandidates: Trait`. +// +// These overflow errors will disappear once we treat these cycles as either +// productive or an error. impl Trait for MultipleNested +//~^ ERROR overflow evaluating the requirement `MultipleNested: Trait` where MultipleCandidates: Trait, + //~^ ERROR overflow evaluating the requirement `MultipleCandidates: Trait` DoesNotImpl: Trait, {} diff --git a/tests/ui/traits/next-solver/cycles/inductive-cycle-but-err.stderr b/tests/ui/traits/next-solver/cycles/inductive-cycle-but-err.stderr index acacaf6a331..7895a263634 100644 --- a/tests/ui/traits/next-solver/cycles/inductive-cycle-but-err.stderr +++ b/tests/ui/traits/next-solver/cycles/inductive-cycle-but-err.stderr @@ -1,16 +1,29 @@ +error[E0275]: overflow evaluating the requirement `MultipleNested: Trait` + --> $DIR/inductive-cycle-but-err.rs:43:16 + | +LL | impl Trait for MultipleNested + | ^^^^^^^^^^^^^^ + +error[E0275]: overflow evaluating the requirement `MultipleCandidates: Trait` + --> $DIR/inductive-cycle-but-err.rs:46:25 + | +LL | MultipleCandidates: Trait, + | ^^^^^ + error[E0277]: the trait bound `MultipleCandidates: Trait` is not satisfied - --> $DIR/inductive-cycle-but-err.rs:46:19 + --> $DIR/inductive-cycle-but-err.rs:54:19 | LL | impls_trait::<MultipleCandidates>(); | ^^^^^^^^^^^^^^^^^^ the trait `Trait` is not implemented for `MultipleCandidates` | = help: the trait `Trait` is implemented for `MultipleCandidates` note: required by a bound in `impls_trait` - --> $DIR/inductive-cycle-but-err.rs:43:19 + --> $DIR/inductive-cycle-but-err.rs:51:19 | LL | fn impls_trait<T: Trait>() {} | ^^^^^ required by this bound in `impls_trait` -error: aborting due to 1 previous error +error: aborting due to 3 previous errors -For more information about this error, try `rustc --explain E0277`. +Some errors have detailed explanations: E0275, E0277. +For more information about an error, try `rustc --explain E0275`. diff --git a/tests/ui/traits/winnowing/global-where-bound-region-constraints-2.rs b/tests/ui/traits/winnowing/global-where-bound-region-constraints-2.rs new file mode 100644 index 00000000000..d422605a292 --- /dev/null +++ b/tests/ui/traits/winnowing/global-where-bound-region-constraints-2.rs @@ -0,0 +1,33 @@ +//@ revisions: current next +//@ ignore-compare-mode-next-solver (explicit revisions) +//@[next] compile-flags: -Znext-solver +//@ check-pass + +// Regression test for trait-system-refactor-initiative#172. +// +// In this test the global where-bound simply constrains the +// object lifetime bound to 'static while the builtin impl +// ends up also emitting a `dyn Any: 'static` type outlives +// constraint. This previously resulted in ambiguity. We now +// always prefer the impl. + +pub trait Any: 'static {} + +pub trait Downcast<T>: Any +where + T: Any, +{ +} + +// elided object lifetime: `dyn Any + 'static` +impl dyn Any { + pub fn is<T>(&self) + where + T: Any, + // elaboration adds global where-clause `dyn Any + 'static: Any` + Self: Downcast<T>, + { + } +} + +fn main() {} diff --git a/tests/ui/traits/winnowing/global-where-bound-region-constraints.rs b/tests/ui/traits/winnowing/global-where-bound-region-constraints.rs new file mode 100644 index 00000000000..3bc8b0438bf --- /dev/null +++ b/tests/ui/traits/winnowing/global-where-bound-region-constraints.rs @@ -0,0 +1,29 @@ +//@ revisions: current next +//@ ignore-compare-mode-next-solver (explicit revisions) +//@[next] compile-flags: -Znext-solver +//@ check-pass + +// Regression test for trait-system-refactor-initiative#172. +// +// The next-generation trait solver previously simply tried +// to merge the global where-bounds with the impl candidates. +// This caused ambiguity in case the where-bound had stricter +// region requirements than the impl. + +trait Trait {} +struct Foo<'a, 'b>(&'a (), &'b ()); +impl<'a> Trait for Foo<'a, 'static> {} + +fn impls_trait<T: Trait>() {} +fn foo() +where + Foo<'static, 'static>: Trait, +{ + // impl requires `'1 to be 'static + // global where-bound requires both '0 and '1 to be 'static + // + // we always prefer the impl here. + impls_trait::<Foo<'_, '_>>(); +} + +fn main() {} |