diff options
Diffstat (limited to 'src/test/ui/coherence/coherence-rfc447-constrained.rs')
-rw-r--r-- | src/test/ui/coherence/coherence-rfc447-constrained.rs | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/src/test/ui/coherence/coherence-rfc447-constrained.rs b/src/test/ui/coherence/coherence-rfc447-constrained.rs new file mode 100644 index 000000000..9d1d86883 --- /dev/null +++ b/src/test/ui/coherence/coherence-rfc447-constrained.rs @@ -0,0 +1,22 @@ +// run-pass +// check that trait matching can handle impls whose types are only +// constrained by a projection. + +trait IsU32 {} +impl IsU32 for u32 {} + +trait Mirror { type Image: ?Sized; } +impl<T: ?Sized> Mirror for T { type Image = T; } + +trait Bar {} +impl<U: Mirror, V: Mirror<Image=L>, L: Mirror<Image=U>> Bar for V + where U::Image: IsU32 {} + +trait Foo { fn name() -> &'static str; } +impl Foo for u64 { fn name() -> &'static str { "u64" } } +impl<T: Bar> Foo for T { fn name() -> &'static str { "Bar" }} + +fn main() { + assert_eq!(<u64 as Foo>::name(), "u64"); + assert_eq!(<u32 as Foo>::name(), "Bar"); +} |