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Diffstat (limited to 'tests/ui/implied-bounds/normalization.rs')
-rw-r--r-- | tests/ui/implied-bounds/normalization.rs | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/tests/ui/implied-bounds/normalization.rs b/tests/ui/implied-bounds/normalization.rs new file mode 100644 index 000000000..f776fc98a --- /dev/null +++ b/tests/ui/implied-bounds/normalization.rs @@ -0,0 +1,58 @@ +// Test that we get implied bounds from complex projections after normalization. + +// check-pass + +// implementations wil ensure that +// WF(<T as Combine<'a>>::Ty) implies T: 'a +trait Combine<'a> { + type Ty; +} + +impl<'a, T: 'a> Combine<'a> for Box<T> { + type Ty = &'a T; +} + +// ======= Wrappers ====== + +// normalizes to a projection +struct WrapA<T>(T); +impl<'a, T> Combine<'a> for WrapA<T> +where + T: Combine<'a>, +{ + type Ty = T::Ty; +} + +// <WrapB<T> as Combine<'a>>::Ty normalizes to a type variable ?X +// with constraint `<T as Combine<'a>>::Ty == ?X` +struct WrapB<T>(T); +impl<'a, X, T> Combine<'a> for WrapB<T> +where + T: Combine<'a, Ty = X>, +{ + type Ty = X; +} + +// <WrapC<T> as Combine<'a>>::Ty normalizes to `&'a &'?x ()` +// with constraint `<T as Combine<'a>>::Ty == &'a &'?x ()` +struct WrapC<T>(T); +impl<'a, 'x: 'a, T> Combine<'a> for WrapC<T> +where + T: Combine<'a, Ty = &'a &'x ()>, +{ + type Ty = &'a &'x (); +} + +//==== Test implied bounds ====== + +fn test_wrap<'a, 'b, 'c1, 'c2, A, B>( + _: <WrapA<Box<A>> as Combine<'a>>::Ty, // normalized: &'a A + _: <WrapB<Box<B>> as Combine<'b>>::Ty, // normalized: &'b B + _: <WrapC<Box<&'c1 ()>> as Combine<'c2>>::Ty, // normalized: &'c2 &'c1 () +) { + None::<&'a A>; + None::<&'b B>; + None::<&'c2 &'c1 ()>; +} + +fn main() {} |