From 17d40c6057c88f4c432b0d7bac88e1b84cb7e67f Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Wed, 17 Apr 2024 14:03:36 +0200 Subject: Adding upstream version 1.65.0+dfsg1. Signed-off-by: Daniel Baumann --- .../assoc-ty-wf-used-to-get-assoc-ty.rs | 27 ++++++++++++++++++++++ 1 file changed, 27 insertions(+) create mode 100644 src/test/ui/implied-bounds/assoc-ty-wf-used-to-get-assoc-ty.rs (limited to 'src/test/ui/implied-bounds/assoc-ty-wf-used-to-get-assoc-ty.rs') diff --git a/src/test/ui/implied-bounds/assoc-ty-wf-used-to-get-assoc-ty.rs b/src/test/ui/implied-bounds/assoc-ty-wf-used-to-get-assoc-ty.rs new file mode 100644 index 000000000..33b746c5e --- /dev/null +++ b/src/test/ui/implied-bounds/assoc-ty-wf-used-to-get-assoc-ty.rs @@ -0,0 +1,27 @@ +// Test for a less than ideal interaction of implied bounds and normalization. +trait Tr { + type Ty; +} + +impl Tr for T { + type Ty = &'static T; +} + +// `<&'a u8 as Tr>::Ty` should cause an error because `&'a u8: Tr` doesn't hold for +// all possible 'a. However, we consider normalized types for implied bounds. +// +// We normalize this projection to `&'static &'a u8` and add a nested `&'a u8: 'static` +// bound. This bound is then proven using the implied bounds for `&'static &'a u8` which +// we only get by normalizing in the first place. +fn test<'a>(x: &'a u8, _wf: <&'a u8 as Tr>::Ty) -> &'static u8 { x } + +fn main() { + // This works as we have 'static references due to promotion. + let _: &'static u8 = test(&3, &&3); + // This causes an error because the projection requires 'a to be 'static. + // It would be unsound if this compiled. + let x: u8 = 3; + let _: &'static u8 = test(&x, &&3); + //~^ ERROR `x` does not live long enough + +} -- cgit v1.2.3