From 218caa410aa38c29984be31a5229b9fa717560ee Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Wed, 17 Apr 2024 14:19:13 +0200 Subject: Merging upstream version 1.68.2+dfsg1. Signed-off-by: Daniel Baumann --- tests/ui/regions/regions-infer-bound-from-trait.rs | 40 ++++++++++++++++++++++ 1 file changed, 40 insertions(+) create mode 100644 tests/ui/regions/regions-infer-bound-from-trait.rs (limited to 'tests/ui/regions/regions-infer-bound-from-trait.rs') diff --git a/tests/ui/regions/regions-infer-bound-from-trait.rs b/tests/ui/regions/regions-infer-bound-from-trait.rs new file mode 100644 index 000000000..610452182 --- /dev/null +++ b/tests/ui/regions/regions-infer-bound-from-trait.rs @@ -0,0 +1,40 @@ +// Test that we can derive lifetime bounds on type parameters +// from trait inheritance. + +trait Static : 'static { } + +trait Is<'a> : 'a { } + +struct Inv<'a> { + x: Option<&'a mut &'a isize> +} + +fn check_bound<'a,A:'a>(x: Inv<'a>, a: A) { } + +// In all of these cases, we can derive a bound for A that is longer +// than 'a based on the trait bound of A: + +fn foo1<'a,A:Static>(x: Inv<'a>, a: A) { + check_bound(x, a) +} + +fn foo2<'a,A:Static>(x: Inv<'static>, a: A) { + check_bound(x, a) +} + +fn foo3<'a,A:Is<'a>>(x: Inv<'a>, a: A) { + check_bound(x, a) +} + +// In these cases, there is no trait bound, so we cannot derive any +// bound for A and we get an error: + +fn bar1<'a,A>(x: Inv<'a>, a: A) { + check_bound(x, a) //~ ERROR parameter type `A` may not live long enough +} + +fn bar2<'a,'b,A:Is<'b>>(x: Inv<'a>, y: Inv<'b>, a: A) { + check_bound(x, a) //~ ERROR parameter type `A` may not live long enough +} + +fn main() { } -- cgit v1.2.3