diff options
Diffstat (limited to 'tests/ui/coherence/coherence-impl-trait-for-trait.rs')
-rw-r--r-- | tests/ui/coherence/coherence-impl-trait-for-trait.rs | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/tests/ui/coherence/coherence-impl-trait-for-trait.rs b/tests/ui/coherence/coherence-impl-trait-for-trait.rs new file mode 100644 index 000000000..195a37f15 --- /dev/null +++ b/tests/ui/coherence/coherence-impl-trait-for-trait.rs @@ -0,0 +1,20 @@ +// Test that we give suitable error messages when the user attempts to +// impl a trait `Trait` for its own object type. + +trait Foo { fn dummy(&self) { } } +trait Bar: Foo { } +trait Baz: Bar { } + +// Supertraits of Baz are not legal: +impl Foo for dyn Baz { } +//~^ ERROR E0371 +impl Bar for dyn Baz { } +//~^ ERROR E0371 +impl Baz for dyn Baz { } +//~^ ERROR E0371 + +// But other random traits are: +trait Other { } +impl Other for dyn Baz { } // OK, Other not a supertrait of Baz + +fn main() { } |