From 64d98f8ee037282c35007b64c2649055c56af1db Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Wed, 17 Apr 2024 14:19:03 +0200 Subject: Merging upstream version 1.68.2+dfsg1. Signed-off-by: Daniel Baumann --- tests/ui/nll/polonius/subset-relations.rs | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) create mode 100644 tests/ui/nll/polonius/subset-relations.rs (limited to 'tests/ui/nll/polonius/subset-relations.rs') diff --git a/tests/ui/nll/polonius/subset-relations.rs b/tests/ui/nll/polonius/subset-relations.rs new file mode 100644 index 000000000..f223ab177 --- /dev/null +++ b/tests/ui/nll/polonius/subset-relations.rs @@ -0,0 +1,29 @@ +// Checks that Polonius can compute cases of universal regions errors: +// "illegal subset relation errors", cases where analysis finds that +// two free regions outlive each other, without any evidence that this +// relation holds. + +// compile-flags: -Z polonius + +// returning `y` requires that `'b: 'a`, but it's not known to be true +fn missing_subset<'a, 'b>(x: &'a u32, y: &'b u32) -> &'a u32 { + y //~ ERROR +} + +// `'b: 'a` is explicitly declared +fn valid_subset<'a, 'b: 'a>(x: &'a u32, y: &'b u32) -> &'a u32 { + y +} + +// because of `x`, it is implied that `'b: 'a` holds +fn implied_bounds_subset<'a, 'b>(x: &'a &'b mut u32) -> &'a u32 { + x +} + +// `'b: 'a` is declared, and `'a: 'c` is known via implied bounds: +// `'b: 'c` is therefore known to hold transitively +fn transitively_valid_subset<'a, 'b: 'a, 'c>(x: &'c &'a u32, y: &'b u32) -> &'c u32 { + y +} + +fn main() {} -- cgit v1.2.3